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Thoracolumbar Spinal Injuries – Evolution of Understanding of fracture Mechanics and Management Options

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Volume 1 | Issue 2 | Sep – Dec 2016 | Page 7-8 | Shailesh Hadgaonkar, Ketan Khurjekar

Authors : Shailesh Hadgaonkar [1], Ketan Khurjekar [1]

[1] Sancheti Institute for Orthopaedics &Rehabilitation, Pune, India.

Address of Correspondence
Dr Shailesh Hadgaonkar
Sancheti Institute for Orthopaedics &Rehabilitation, Pune, India
Email: editor.ijspine@gmail.com

Introduction

This symposia on thoracolumbar fractures is aimed at providing an overview to the reader with respect to evolving trends in fracture diagnosis and management.
There has always been controversies in treating thoracolumbar spine injuries with neurological deficit, but as we know the goal of managing these T-L junction injuries is to maintain the sagittal alignment for mechanical stability and to give additional support for rehab and physiotherapy for neurological recovery. The main aim of thoracolumbar fracture surgery is to give structural support to the spinal column for wheelchair mobilization in cases with complete injury and paraplegia. We have found significant improvement in quality of life in patients who were operated for these severe thoraco lumbar spinal injuries. As we all know the most common level of these injuries is T 12 and L1, sustaining from the high velocity trauma. The flexibility at thoraco lumbar junction, the thoracic rib cage ending at the junctional level, coronal alignment of facet joint in thoracic spine and the changes in the lower thoracic facets to less coronal alignment is likely to cause fracture dislocations. Various transitional zone injuries- between T 11- L2 are approximately 50 – 60 % of all injuries. Most common reason for these injuries – are fall from height and high velocity RTA. There is a significant association of other injuries such as chest, abdominal, vascular injuries and also head injuries with these fracture dislocations.
It is paramount to evaluate these patients in detail, thorough clinical and neurological assessment is mandatory. The standard American Spinal Injury Association (ASIA) guidelines should be followed in neurological assessment. Associated relevant investigations as the X-rays and MRI scans will guide for non-operative Vs operative management. Additional modalities such as CT scans and 3D reconstruction is important clinically unstable and high grade T-L injuries. Primary assessment and medical management is important to stabilize the patient before planning the surgery.

Evolution of classification systems :
Various different classification system have evolved from the World War I and II days, as Bohler in 1930 classified T-L fractures into five categories :-
1- Compression fractures
2- Flexion /distraction injuries
3- Extension fractures
4- Rotational injuries
5- Shear fractures
Watson Jones in 1938 classified T-L injuries adding instability to Bohler’s classification. The most important factor in Watson Jones classification was description of Posterior ligamentous complex (PLC) in spine stability, as they felt the integrity of interspinous ligament is most important stability factor.
Nicole in 1949, further classified using anatomical classification with emphasis on interspinous ligament integrity. He described the stability structures as the vertebral body, disc, intervertebral joint, and interspinous ligament. This classification serves as a foundation for subsequent classifications.
Holdsworth in 1963, described Two column theory and he emphasized the spinal stability on posterior ligamentous complex (PLC) stability. Kelly and Whitesides attempted to modify Holdsworth classification, as they specifically mentioned anterior column as solid vertebral body whereas posterior column as posterior elements and neural arch. Also they emphasized the treatment of neurological deficit.
Dennis in 1983, came up with a new concept – Three column theory using the radiological parameters. He provided a new insight in detailing the classification into anterior, middle and posterior column. They described the middle column – osteo-ligamentous complex injury is the primary determinant of mechanical spinal stability.
Mcafee et al described the classification based on CT scans of 100 consecutive patients and divided into 6 groups. This was the most detailed classification system in the 1980’s. They described the height loss of vertebral body, facetal joint subluxation, fragments in the spinal canal, progressive neurological deficit, kyphosis angle because of instability was assessed with the CT scan. As per their criteria translational and flexion/rotational fracture dislocation and posterior ligamentous complex (PLC) injury with kyphosis more than 30 degrees angle should undergo surgery.
In 1994 Mc Cormack classified on load sharing concept, which focuses more on location of the fracture in the vertebral body.
Then in 1994, Magrel et al came up with classification based on evaluation of 1445 cases and classified into 3 types and 53 injury models.
In 2005, Vaccero et al came up with Spine trauma study group – Thoraco Lumbar Injury Classification System (TLICS) which takes a detail note on fracture mechanism, the intact PLC status and the neurological status of the patient.
TLICS points:
Fracture Mechanism
Compression fracture 1
Burst fracture 1
Rotational fracture 3
Splitting 4
Neurological involvement
None 0
Nerve root 2
Medulla spinalis, conus medularis-
– Incomplete 3
– Complete 2
Cauda equina 3
Posterior ligamentous complex
Intact 0
Possibly injured 2
Injured 3

Surgical indication is for cases with 5 points or more, cases with 4 points are between surgical vs non surgical, and cases with 3 or less points are non surgical. It is quite a comprehensive and popular classification in clinical practice and many centers prefer to use this classification worldwide.
Recently AO Spine knowledge forum has proposed a comprehensive modified AO classification based on morphology of fracture, neurology status and description of relevant patient specific modifiers
These classifications signify the growth in our understanding of pahtomechanics of the spine fracture as well as takes into account our growing expertise in the offering better surgical options to the patients.

Management Options:
Various management options are discussed in the current symposia and most of the options are individualised depending on the etiology and extent of fracture. Few general rules are noted below –
– Cases where there is retropulsion up to 40- 50 degrees without neurological deficit with intact PLC we can attempt indirect decompression and distraction in first 5 -6 days after the injury.
– Cases with less angulation and wedging with minimal kyphosis can be dealt with short segment fixation.
– Interlink in long construct always adds-up to the stability. Reduction of the dislocation with various maneuvers always beneficial for sagittal profile.
– Role of steroid is controversial post T-L injury with neurological deficit and is rarely used worldwide.
– Role of minimally invasive spine (MIS) surgery is evolving and needs a longer follow up. MIS surgery helps in reducing the bleeding, morbidity in selective cases.
– There is a significant role of rehabilitation post-surgery, in cases of T-L fractures with neurological deficit. Stem cells are promising in animal and Fish models in research labs and we are very hopeful about the same in humans.
Most of the above options are discussed in details in the symposia and we would encourage the readers to go through the articles. Ultimately the clinical evaluation summed with the radiological parameters will decide the management plan as cases with instability, neurological deficit and progressive neurological worsening cases will need surgical intervention. A lot of cases can be conserved with careful monitoring.
We thank all the authors and contributors for participating in the symposia and invite interested readers to participate as symposium editors or authors. Please write to us by email and provide your suggestions and comments.

How to Cite this Article: Hadgaonkar S, Khurjekar K. Thoracolumbar Spinal Injuries Evolution of Understanding Fracture Mechanics and Management Options . International Journal of Spine Sep-Dec 2016;1(2):7-8.

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Shoulder Balance and Scoliosis

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Volume 1 | Issue 1 | Apr – June 2016 | Page 31-32|Ketan Khurjekar[1].

Authors :Ketan Khurjekar[1]

Sancheti Institute for Orthopaedics &Rehabilitation, Pune, India

Address of Correspondence

Dr Ketan Khurjekar
Sancheti Institute for Orthopaedics &Rehabilitation, Pune, India

Email: kkhurjekar@googlemail.com

Abstract

Abstract: Shoulder imbalance is a fairly new outcome variable that is been associated with complex spinal deformities. The presentation of should imbalance is variable and depends on the extent, severity of primary curve, compensatory curves and overall balance of the spine both in sagittal and coronal planes (rotatory planes). It is definitely an important outcome measure in terms of satisfactory patient outcome, however factors that affect it are still unclear and more studies are required. Current article focusses on the basics of shoulder imbalance and currently available methods of measuring it.
Key Words: Adult spinal deformity, shoulder imbalance, cosmoses.

Introduction
Shoulder Balance and Scoliosis
Scoliosis though termed as a coronal deviation in normal architecture of spine, it is often found that there is sagittal imbalance associated with the rotation of the spinal column. Scoliosis is a 3-D deformity and its rotation element was not taken into consideration till recent times. Sagittal imbalance or coronal deviation along with rotational mal-alignment gives obnoxious spinal deformity and severity is perceived more because of shoulder imbalance. Shoulder imbalance is reported as difference in shoulder asymmetry. Residual shoulder asymmetry ruins the result of good anatomical Cobb to Cobb correction. Patient undergoing spinal fusion surgery did not do well unless the sagittal Balance is corrected. It plays important role in cosmesis achieved after surgery. It is unclear, that which factors of scoliosis complex determines the shoulder balance. How does preoperative severity of shoulder imbalance affect the post operative outcome still remains speculative. Why only proximal thoracic and main thoracic curve are given significance when we talk about shoulder balance is topic of discussion? Just as a corollary, for years abnormal abdominal reflex was considered to be indicator of intraspinal problem. Yngve demonstrated that abnormality of abdominal refelex was seen in 27 % of normal individuals[1]. Shoulder imbalance associated with proximal curve, dictates the long fusion surgery till T2 which balances out the shoulder and helps achieve good cosmetic correction. If left shoulder is higher > 5 mm in right proximal thoracic curve, then including proximal thoracic curve in instrumentation is mandatory. As per Lenke et al, if left shoulder is higher in a right proximal thoracic curve, upper instrumented vertebra (UIV) would be T2. If right shoulder is higher, then UIV would be T4. If both shoulders are equal, then fusion would be restricted to T3 [2]. Pelvic girdle is base of spine foundation. Any deviation or malalignment of spine is noted as abnormal pelvic tilt. But pectoral girdle has no direct attachment. So it has been postulated that correction of chest wall deformities can correct shoulder level and Scapulae to give desired shoulder balance [3].
Few of the Current practices of measuring shoulder Imbalance [4]
· Curve pattern on standing AP and Lateral (whole Spine Scannograms) are mandatory to measure shoulder asymmetry
· T1 tilt- Positive T1 tilt is defined as the angulation of upper end plate of T1 to the horizontal with the proximal vertebral body up and right lower vertebral body down
· Clavicle Angle- Intersection of horizontal line and tangential line connecting the higher two points of each clavicle. Positive clavicle angle means left clavicle is up and right clavicle is down
· T1-ICL correlation- T1 vertebral tilt and intercoracoid line (ICL) tilt have simplified measurement of shoulder balance. T1-ICL relationship is concordant or discordant. Relationship is concordant if T1 is tilted to the same side as that of ICL. Similarly it is discordant if T1 has tilted in opposite direction of ICL [3].
· Coracoid Height Difference- Difference between two horizontal lines drawn from each coracoid will tell us about Coracoid Height difference.
· Trapezius length- Showed weak correlation with post-operative shoulder balance
· First rib- Clavicle height- Vertical distance of first rib apex to superior clavicle
· RSH- radiographic Shoulder height- Graded height difference of Soft tissue shadow directly superior to acromio-clavicular joint in AP view. When imbalance is more than 3 cm, it is called as Significant Shoulder Imbalance. Moderate imbalance would be 2 to 3 cm and less than 1 cm would be minimal shoulder imbalance.
In a series of 112 cases, Kuklo et al4 concluded that the clavicle angle and not the T1 tilt is the best predictor of preoperative and post operative shoulder balance. Standing Proximal Cobb and side bending Cobb is considered as essential part of survey.
Determination of UIV would have bearing on post-op shoulder balance. Whether to stop at T2 or T3 or T4 is unclear. Suk et al has suggested that neutral vertebra of the proximal thoracic curve should be selected as UIV irrespective of shoulder level particularly when all pedicle screw construct is used [5]. However above findings are true if the curve T1-ICL concordant. Means if the T1 is tilted along with the proximal curve then depressing the neutral vertebra or T1 will get the shoulder balanced. As against that, if the proximal thoracic curve is T1-ICl discordant, then depressing T1 will further enhance the shoulder imbalance [3]. Only radiological shoulder balance doesn’t correlate with the clinical appearance. Correcting T1 tilt radiologically will correct Shoulder balance has proven to be myth beyond doubt. Researchers from Turkey evaluated shoulder balance radiologically and clinically in healthy adults and proved that shoulder balance in healthy adults doesn’t exist [6].
Healthy adolescent patients almost 19 % had asymmetric shoulders and almost 72 % had side to side difference of < 1 cm. None of the individuals ever complained of shoulder imbalance. The radiological shoulder balance parameters reliably reflect the clinical appearance. Coracoid height difference is taken into consideration when shoulders are included in radiographs and clavicular tilt angle is considered when shoulders are obviated. Researchers from Japan have classified shoulder balance broadly into medial and lateral shoulder height asymmetry. Medial differences reflected in trapezial prominence created by upward tilted proximal ribs and tilted T1. Lateral shoulder height asymmetry correlates weakly with clavicular angle. Correlation of trapezial prominence is more predictable to compare after scoliosis surgery [7]. Shoulder balance is considered as paramount indicator in cosmesis correction. It has significant impact of patient’s self-perception [8]. Generally anterior shoulder balance is perceived by patient and posterior shoulder balance is perceived by clinician. From patient’s perspective, achieving anterior shoulder balance is vital. Both, anterior and posterior shoulder balance were thought to be correlating equally. Unlike, it is showing weak correlation and it is recommended for clinicians and surgeons to evaluate both sided in planning deformity correction, particularly Lenke type 2 curves [8]. Chinese workers have affirmed that radiologic parameters alone will not guide post-operative shoulder balance. We should pay more attention to clinical cosmetic correction than only radiological angle restoration to get proper shoulder balance. We should not only include shoulder height but should also include the shoulder angle, axilla angle and areal balance between left and right shoulder. Qiu et al has suggested that estimate of shoulder height, which is intersection of clavicle and rib cage is the most reliable landmark. It will guide in assessing shoulder balance to better extent [9]. To Summarise, the shoulder balance is an area of complexity with many researchers with their experienced thought process. The common mandate is to get satisfactory cosmetic correction of scoliosis for patient as well as clinician.

References 

1. Yngve D. Abdominal reflexes J Pediatric orthop. 1997: 17(1): 105-108
2. Lenke LG, Bridwell KH, O’Brien MF, et al. Recognition and treatment of proximal thoracic curve in adolescent idiopathic scoliosis treated with Cotrel-Dubousset instrumentation. Spine. 1994;19:1589-1597
3. Menon KV, Tahasildar N, Pillay HM, Ambuselvum M, Jayachandren RK. Patterns of Shoulder Balance in Idipopathic Scoliosis. J Spinal Disord Tech 2014;27:401-408
4. Kuklo TR, Lenke LG, Graham EJ, Won DS, Sweet FA, Blanke KM, Bridwell KH. Correlation of radiographic, clinical, and patient assessment of shoulder balance following fusion versus nonfusion of the proximal thoracic curve in adolescent idiopathic scoliosis. Spine (Phila Pa 1976). 2002 Sep 15;27(18):2013-20.
5. Suk SI, Kim WJ, Lee CS, Lee SM, Kim JH, Chung ER, Lee JH. Indications of proximal thoracic curve fusion in thoracic adolescent idiopathic scoliosis: recognition and treatment of double thoracic curve pattern in adolescent idiopathic scoliosis treated with segmental instrumentation. Spine (Phila Pa 1976). 2000 Sep 15;25(18):2342-9..
6. Akel I, Pekmezci M, Hayran M, Genc Y, Kocak O, Derman O, Erdogan I, Yazici M. Evaluation of shoulder balance in the normal adolescent population and its correlation with radiological parameters. Eur Spine J. 2008;17: 348-354.
7. Ono T, Bastrom TP, Newton PO. Defining 2 components of shoulder imbalance. Spine 2012; 37: E1511-E1516
8. Yang s, Feuchtbaum, Werner BC, Cho W, Reddi V, Arlet V. Does anterior shoulder balance in adolescent idiopathic scoliosis correlate with posterior shoulder balance clinically and radiologically. Eur Spine J. 2012: 21: 1978-1983
9. Qiu XS, Ma WW, Li WG, Wang B, Yu Y, Zhu ZZ, Qian BP, Zhu F, Sun X, Ng BK, Cheng JC, Qiu Y. Discrepancy between radiographic shoulder balance and cosmetic shoulder balance in adolescent idiopathic scoliosis patients with double thoracic curve. Eur Spine J. 2009 Jan;18(1):45-51.

How to Cite this Article: Khurjekar K. Shoulder Balance and Scoliosis. International Journal of Spine Apr – June 2016;2(1):31-32 .

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Management Strategies and Selection of Fusion Levels in Adult Spinal Deformities

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Volume 1 | Issue 1 | Apr – June 2016 | Page 25-30|Kshitij Chaudhary[1], Ranjith Unnikrishnan[2].

Authors :Kshitij Chaudhary[1], Ranjith Unnikrishnan[2]

[1] Department of Spine Surgery, Mumbai, Maharashtra, India
[2] Kerala Institute of Medical Sciences, Trivandrum, Kerala, India

Address of Correspondence
Dr. Kshitij Chaudhary
206-3A, Vaishali nagar, KK Marg, Jacob Circle, Mahalaxmi East
Mumbai 400011.
Email: chaudhary.kc@gmail.com

Abstract

Abstract: Adult spinal deformity (ASD) is fast becoming a global spinal epidemic. Decision making in adult deformity is a complex process and with each passing year, the treatment protocols are evolving as new evidence comes to light. The decision to choose surgery is not only complex but also patient specific. The surgical options can be broadly classified into three groups in order of increasing complexity and surgical invasiveness: 1) focal decompression only, 2) decompression with limited fusion, and 3) fusion of the entire curve. Of the many controversies plaguing adult spinal deformity, choosing end levels of fusion is the subject matter of ongoing debate. This narrative review makes an attempt to provide general guidelines for selecting fusion levels based on the current evidence.
Key Words: Adult spinal deformity, surgery, degenerative scoliosis, fusion levels, review

Introduction
As the world’s population ages, adult spinal deformity (ASD) is fast becoming a global spinal epidemic. Although accurate estimates are difficult, the prevalence is reported to be as high as 60% in individuals older than 60 years [1]. Adult deformity can be of two types. Adult idiopathic scoliosis represents patients who have a history of idiopathic scoliosis in childhood that present with symptoms related to degenerative arthritis within the curve. Degenerative or De novo scoliosis represents patients without preexisting spinal deformity who present with spinal deformity secondary to degenerative spinal changes [2]. It is hypothesized that asymmetric disc degeneration and facet arthritis with lateral and/or rotatory listhesis is responsible for the development of de novo scoliosis in adults. Usually, the age of presentation of patients with degenerative scoliosis is in the 6th decade. The typical presentation is either axial back pain or radiculopathy (radicular or neurogenic claudication). With severe deformity, patients may present with a change in body habitus, abnormal posture and may complain of ill-fitting clothes. One of the fundamental difference between treating adolescent deformity and adult deformity is that the treatment choice is guided by the clinical presentation rather than radiological parameters. Although precise therapeutic guidelines for treating these patients are not defined, clinicians should take into consideration certain general evidence-based principles when treating these patients. Decision making in adult deformity is a complex process and with each passing year, the treatment protocols are evolving as new evidence comes to light. In general, with exception of patients presenting with acute neurological deterioration, nonoperative treatment is the first option offered to patients. The surgical options can be broadly classified into three groups in order of increasing complexity and surgical invasiveness: 1) focal decompression only, 2) decompression with limited fusion, and 3) fusion of the entire curve [3]. Surgery is indicated in patients who fail conservative care and continue have ongoing back pain, neurological symptoms or deformity progression. The decision to choose surgery is not only complex but also patient specific. Innumerable factors need to be considered before finalizing on surgery, and the patient should be part of this decision-making process. Of the many controversies plaguing adult spinal deformity, choosing end levels of fusion is the subject matter of ongoing debate. While limited fusion and decompression is associated with lower postoperative complications, these patients may soon become symptomatic due to adjacent segment degeneration if the fusion levels are not chosen wisely. Extensive fusion of the entire deformity not only carries a significant surgical risk, but is also associated with complications related to selection of end-levels of fusion. At the distal end the debate is whether to fuse or not to fuse to sacrum. At the proximal end, proximal junctional kyphosis remains a risk and, therefore, choice of upper end-level of fusion requires special attention. This review article makes an attempt to provide general guidelines for selecting fusion levels based on the current evidence.

Radiographic evaluation of ASD patient:
Standing full spine radiographs:
Standing radiographs are of paramount importance. Patients with spinal deformity should be evaluated using full spine radiographs that include the external auditory canal and the femoral heads. The position of the arms with 30º shoulder flexion has the least impact on sagittal alignment [4].
Frontal Radiograph
1. Cobb angle: measure for all curves, including fractional curves. Identify stable, neutral and end vertebrae.
2. Lateral listhesis: adjacent vertebrae are relatively neutral in relation to each other
3. Rotatory listhesis: cephalad vertebra is rotated compared to the caudad vertebra
4. Coronal balance: offset of the C7 in relation to the central sacral vertical line is measured, with offsets of more than 5 cm considered as abnormal.
5. Clavicle angle: angle between a line joining two clavicles (most cephalad points of both clavicles) and the horizontal reference line. It is a measure of shoulder imbalance.
6. Pelvic obliquity: angle between the highest points of iliac crest or sacral ala and the horizontal reference line. If there is a pelvic obliquity it is imperative to rule out an oblique take off of L5 and limb length inequality.

Lateral Radiograph
1. Thoracic kyphosis: as measured from T4 to T12. (Fig. 1)
2. Lumbar lordosis: as measured from L1 to S1. (Fig. 1)
3. Global Sagittal balance (Fig. 1): These parameters have been shown to correlate with self-reported pain and disability (HRQOL measures) [5,6].
a. Sagittal C7 plumbline is drawn from the centroid of C7. Measure the horizontal offset of from this plumbline and the posterior superior corner of S1.
b. T1 and T9 spinopelvic parameters: these are angles between the the vertical plumbline dropped from the center of T1 or T9 vertebral body and the line joining this center to the center of the femoral axis. These are a measure of sagittal imbalance.
4. Pelvic parameters (Fig 2): Pelvic incidence is a morphological parameter that remains relatively constant throughout adulthood. It is the sum of sacral slope and pelvic tilt (PI=SS+PT) which vary according to the pelvic position. Normative values are: 52º for PI, 12º for PT and 40º for SS [7].
5. Anterior or posterior vertebral subluxation.
6. Osteophytes and status of disc collapse: These are markers or stability of a particular motion segment

Figure 1

Adult spinal deformity classification:
Unlike the widely popular and established Lenke classification for adolescent idiopathic scoliosis, the classification systems for adult spinal deformity continue to evolve as increasing evidence accumulates. The attempt is to try to link the classification system to a treatment algorithm that can reliably predict the outcome of surgical intervention. The adult spinal deformity committee of the Scoliosis Research Society has developed the SRS-Schwab Adult Spinal Deformity classification that has been shown to be comprehensive and predictive of outcomes and complications in the management of ASD [8].
Flexibility films
When planning a surgery, it is important to assess the flexibility of the deformity. It is extremely useful to compare the standing radiographs with the supine films. Supplementary radiographs such as push-prone films, traction, and bending films may also be useful. Silva and Lenke have categorized curve flexibility into three categories: flexible, stiff and stuck. “Flexible” deformities will correct passively by at least 50% and will not require additional release procedures. “Stiff” deformities correct 25-50% and may require an anterior release or posterior facet resections (Ponte osteotomies). “Stuck” deformities are quite rigid and need three column osteotomy [3].

Figure 2

MRI and CT scan
MRI is useful to evaluate the spinal canal in patients with neurological symptoms. The location of spinal stenosis has important implications on surgical treatment. CT myelogram may be useful in patient with contraindications to MRI. In patient with severe deformity, multiplaner CT reconstruction may give more information compared to MRI. Osteophytosis and autofused segments are readily diagnosed on CT scan and this too has ramifications on surgical treatment.

Surgical options

1) Decompression without fusion:
Although this is an attractive option for the elderly with comorbidities, it can be successfully employed in only a subset of patients. It is ideal for a patient with neurological symptoms (radicular pain) with little or no back pain. The nature of stenosis should be either central canal or lateral recess, and it should be possible to perform a limited decompression to achieve nerve decompression. Foraminal stenosis requires wider destabilizing bony resection and is usually not suitable for decompression only procedure. Besides, if the comparison between standing and supine films suggest a collapsing nature of the deformity, this option is not ideal. Radiographically, these curves should be mild (<15-20º) with a reasonable global sagittal balance and no lumbar kyphosis. The segments that need decompression should be stable as indicated by the presence of osteophytes or collapsed disc space and should not demonstrate subluxation (>2mm) on dynamic or standing radiographs. However, decompression may result in curve progression and worsening of symptoms, especially if done at the apex of the deformity.

2) Decompression with limited fusion within the deformity:

This option involves performing a limited fusion in the area of decompression. This is suitable for a patient with predominant leg pain (neurogenic claudication) who will require extensive decompression (e.g. severe lateral recess or foraminal stenosis, previous laminectomy, dynamic stenosis). The curve should be relatively small (<30º) without significant lumbar kyphosis or global imbalance. If there is an indication of segmental instability (vertebral subluxation >2mm, anterior, lateral or rotatory) without significant osteophytes or disc settling the segment should be fused.

Choosing fusion levels in limited fusion
The concern in limited fusion is accelerated degeneration of adjacent segment leading to spinal stenosis and progression of deformity. At the proximal end, it is advisable to include the adjacent segment that has a rotary subluxation or segmental kyphosis within the fusion [9]. Fusion from apex to sacrum have been shown to have poorer outcomes, hence if possible, fusion should not stop at the apex of the deformity [10]. At the proximal end, a decision must be made whether to extend fusion to sacrum. Frequently, the concavity of the fractional curve (L4 to S1) results in foraminal stenosis at L5-S1. Therefore, if the decompression involved L5-S1 segment the fusion should extend to the sacrum. Preexisting pathology (listhesis, pars defect) or severe disc degeneration are indications for extending fusion to the sacrum.
Hansraj et al in a large cohort of symptomatic spinal stenosis with degenerative scoliosis <20º, reported a 95% success rate (no revision surgery) of decompression alone surgery at four years follow-up [11]. Transfeldt et al compared three surgical groups: decompression only, limited fusion and full curve correction. Full curve correction group had the highest complication rate, the worst Oswestry results but it was second best in patient satisfaction. Decompression alone had the lowest complication rate but the lowest patient satisfaction rate. Limited fusion had intermediate results between these two groups [10]. Another retrospective study by Daubs et al found that in patients with curves <30º limited fusion groups outperformed the decompression only group for up to 5 years [12].

3) Fusion of entire deformity with or without decompression

This is indicated in patients with significant back pain with or without leg pain as a result of spinal deformity. Typically, these curves are large (>45º), with significant segmental subluxations (>2mm) or instability. The goal of curve correction is to restore global and regional imbalance. Literature indicates that proper restoration of the sagittal profile is critical for improvement of postoperative outcomes as measured by HRQOL scores [13].
The goals of surgery are to correct the deformity to achieve the following:
1) Lumbar lordosis should be corrected to within 10º of the pelvic incidence (PI-LL = ±10 degrees)
2) Sagittal vertical axis should be restored within 5 cm of the posterior superior corner of sacrum
3) Pelvic tilt should be restored to less than 25º
Surgimap software is an excellent graphical tool for preoperative planning to achieve these goals [14]. Depending on the flexibility of the deformity, various release procedures, ranging from facetectomy to three column osteotomy are employed to achieve these goals.

a) Proximal fusion level:
The most feared complication at the proximal end of the construct is PJK (proximal junctional kyphosis). Proper selection of proximal fusion level or the upper instrumented vertebra (UIV) may help reduce the risk of this complication

1) The UIV should be a stable vertebra. Preferable horizontal rather than tilted vertebra.
2) Evaluate the adjacent segment for spinal stenosis, olisthesis, facet arthropathy, and disc degeneration. One should consider including such level within the fusion.
3) Avoid stopping that the apex of focal or regional kyphosis. Physiological apex in the thoracic spine is around T6 and it is better to stop short (T10) or go beyond this level (T4 or above).
4) Avoid stopping in thoracolumbar region, if the thoracic spine has vertebral compression fractures or thoracic hyperkyphosis.
5) Shoulder balance needs to be considered. Unlike adolescent curves, the compensatory curves in adult deformity do not correct with reduction of the primary deformity. The compensatory curves may be stiffer due to degenerative changes and may require inclusion in the fusion to achieve should symmetry.
It is disputable whether to stop the fusion at T10 or L1/L2. Often the stable vertebra is going to be T12. It is a transitional area, and hence most authors recommend bypassing the area and going to T10, which is in a more stable region of the spine even if it means increasing the extent of surgery. Kuklo et al reported that only two of the 20 patients had good to excellent results when stopping at L1 or L2 [15]. However, Kim et al compared three groups with UIV of T9, T11, and L1 and found no difference in outcome at 4.5 years. [16] Cho et al concluded that there was no difference in adjacent segment problems between fusion to T10 and fusion to T11 or T12. They concluded that fusion to T11 or T12 was acceptable when UIV was above the upper end vertebra [17].

b) Distal fusion level
In degenerative scoliosis, the most common radiographic anomaly is L3-4 rotatory subluxation with a fixed tilt of L4-5. Hence, it is usually not possible to stop at L3 or L4 in degenerative scoliosis. Therefore, the options available for distal fusion level are L5, sacrum, or pelvis.

L5 or Sacrum?

This decision can be difficult and challenging. Advantages of stopping at L5 are preservation of lumbosacral motion, reduced stress on SI joints, lower operative time and lower nonunion rate [18]. However, stopping at L5 may be associated with adjacent segment disease and increase in sagittal imbalance as the L5-S1 disc collapses and goes into kyphosis. Edwards et al found adjacent segment disease in L5-S1 to be 61% out of which approximately 2/3rd had an increase in SVA by more than 5cm. Extension of fusion to sacrum was performed in 23% patients, and a further 17% were offered surgery, but they declined [19]. Contrary to the popular notion that deep seated L5 is relatively stable, this study found that loss of L5 fixation was not uncommon in such patients.
Obtaining fusion to sacrum can be a challenge and many have reported a significant nonunion rate [20,21]. In addition, it adds to the surgical burden and increases surgical time and blood loss. Bridwell [22] has recommend that fusion should extend to sacrum in the following situations:
1. L5-S1 spondylolisthesis
2. Central or foraminal stenosis at L5-S1
3. Oblique take off of L5 >15 degrees
4. Severe L5-S1 disc degeneration

L5 or pelvis?

Much of the ongoing debate has shifted from L5 versus S1 to a choice between L5 versus pelvis. Several studies have reported S1 screw failure and pseudarthrosis in patients with long fusion to the sacrum [23-25]. Iliac fixation, particularly with iliac screws, has gained popularity in the recent years. The downside of iliac screws could be their potential for loosening, implant prominence, and pain which may necessitate a hardware removal. However, this complication is not very common [18]. Some authors advocate an interbody fusion at L5-S1 (TLIF or ALIF) in addition to sacro-plevic fusion in patients with long constructs (>3 levels) to reduce failure rate due to pseudarthrosis [7].

Indications for extending fixation to pelvis are: [26]
1) Long construct: There is no clear definition of a long construct, but many surgeons recommend including the pelvis if the UIV is L2 or above.
2) Inability to achieve a good coronal or sagittal balance intraoperatively.
3) Poor sacral fixation (e.g. in osteoporosis)
4) High risk of pseudarthrosis (e.g. smokers, diabetics)
5) Inability to achieve a good interbody fusion at L5-S1
6) In patients undergoing three column osteotomies in the lower lumbar spine.

Minimally invasive techniques:
Minimally invasive, muscle sparing, tubular techniques are becoming popular to treat lumbar degenerative disorders. They have especially been useful in adult deformity patients to achieve decompression without damaging midline structures and help preserve the posterior tension band. They can also be used for limited fusion operations to reduce the surgical footprint and may reduce adjacent segment problems. However, in long constructs, it is still debatable whether minimally invasive techniques are as effective as open techniques in restoring sagittal and coronal balance [27].

Table 1

Case examples:

Case 1: (Fig. 3 and 4) Decompression with limited fusion
A 62-year old woman presented with predominant leg side neurogenic claudicatory pain attributed to foraminal stenosis (L4-5 and L5-S1) in the concavity of the fractional curve. The patient had failed all conservative measures. Standing radiographs (Fig. 3a) demonstrate a left sided lumbar curve of 25º with a fractional curve from L4 to sacrum of 18º. Supine films (Fig. 3b) show that the lumbar curve corrects to 19º and the fractional curve reduces to 10º. This suggests that the foraminal stenosis at L4-5 and L5-S1 is dynamic in nature, and a simple decompression is not going to relieve her of her symptoms. The lumbar lordosis is 50º, and it is within 10 degrees of the pelvic incidence (56º) (Figure 3c). The pelvic tilt is 7º. The global sagittal and coronal balance is normal. There is rotatory subluxation between L3-4 and anterior subluxation of L4-5 that is more than 2mm (Figure 3a), which is an indication for fusion to extend to L3 even though she does not have spinal stenosis at L3-4. Fusion was extended to sacrum as L5-S1 level had symptomatic stenosis (Fig. 3a). A TLIF procedure was added at L5-S1 level to improve foraminal height as well as to improve fusion rate. Satisfactory tricortical purchase was obtained in the sacrum and hence iliac fixation was deferred.

Figure 3 and 4

Case 2: (Fig. 5 and 6) Focal decompression with full curve correction using a long construct
A 74-year man presented with significant neurogenic claudication in both legs and severe back pain that has been unresponsive to conservative measures. The patient did not have any focal neurological deficit. Standing radiographs revealed 52º left lumbar curve with a fractional curve of 17º (Fig. 5a). There was a severe coronal imbalance (+8cm). Lateral standing radiographs showed positive sagittal imbalance (SVA +7cm), lumbar lordosis of -17º, and pelvic incidence of 59º. There was some amount of compensatory pelvic retroversion as indicated by a high pelvic tilt (PT 29º) (Fig. 5b). The goal of surgery was to achieve neural decompression as well as to restore global and regional balance (ideal postoperative alignment should have PT of <25º, PI-LL= ±10º and SVA <5cm). Surgery involved laminectomy and decompression of neural structures from L3 to S1 and posterior instrumented fusion from T10 to Pelvis (Fig. 6a). The flexibility and supine films showed 30% correction and posterior Ponté osteotomies were performed to release the deformity. The stable vertebra was T11 on preoperative radiographs and hence fusion was extended to T10, which is relatively stable segment due to its connection to the rib cage. There was no hyperkyphosis and hence fusion was not extended to the upper thoracic spine. As the fusion construct was long, additional iliac fixation was added to protect the S1 screw and improve the chances of achieving a successful lumbosacral fusion. Postoperative standing radiographs show a good restoration of coronal and sagittal balance. The lumbar lordosis is restored to -49º. Pelvic incidence minus lumbar lordosis is 11 degrees and there is improvement in pelvic tilt to 22º. SVA improved from +7cm to +1cm (Fig. 6).

Figure 5 and 6

Conclusions

The treatment of adult spinal deformity, surgical decision making and selection of fusion levels remains a complex and controversial process. Surgery in this population is risky and fraught with complications. Over the last few decades, our knowledge regarding these deformities has taken a quantum leap. However, there is still a lot of ground to cover. Therapeutic guidelines and classification system will evolve as researchers continue to search for answers.

References 

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2. Aebi M. The adult scoliosis. Eur Spine J 2005;14:925–48.
3. Silva FE, Lenke LG. Adult degenerative scoliosis: evaluation and management. Neurosurg Focus 2010;28:E1.
4. Vedantam R, Lenke LG, Bridwell KH, Linville DL, Blanke K. The effect of variation in arm position on sagittal spinal alignment. Spine 2000;25:2204–9.
5. Glassman SD, Bridwell KH, Dimar JR, Horton W, Berven S, Schwab F. The impact of positive sagittal balance in adult spinal deformity. Spine 2005;30:2024–9.
6. Lafage VC, Schwab F, Patel A, Hawkinson N, Farcy J-P. Pelvic Tilt and Truncal Inclination. Spine 2009;34:E599–E606.
7. Blondel B, Wickman AM, Apazidis A, Lafage VC, Schwab F, Bendo JA. Selection of fusion levels in adults with spinal deformity: an update. Spine J 2013. doi:10.1016/j.spinee.2012.11.046.
8. Schwab F, Ungar B, Blondel B, Buchowski J, Coe J, Deinlein D, et al. Scoliosis Research Society-Schwab adult spinal deformity classification: a validation study. Spine 2012;37:1077–82. doi:10.1097/BRS.0b013e31823e15e2.
9. Cho K-J, Suk S-I, Park S-R, Kim J-H, Kim S-S, Lee T-J, et al. Short fusion versus long fusion for degenerative lumbar scoliosis. Eur Spine J 2008;17:650–6. doi:10.1007/s00586-008-0615-z.
10. Transfeldt EE, Topp R, Mehbod A, Winter RB. Surgical outcomes of decompression, decompression with limited fusion, and decompression with full curve fusion for degenerative scoliosis with radiculopathy. Spine 2010;35:1872–5. doi:10.1097/BRS.0b013e3181ce63a2.
11. Hansraj KK, Cammisa FP, O’Leary PF, Crockett HC, Fras CI, Cohen MS, et al. Decompressive surgery for typical lumbar spinal stenosis. Clin Orthop Relat Res 2001:10–7.
12. Daubs MD, Lenke LG, Bridwell KH, Cheh G, Kim YJ, Stobbs G. Decompression alone versus decompression with limited fusion for treatment of degenerative lumbar scoliosis in the elderly patient. Evidence-Based Spine-Care Journal 2012;3:27–32.
13. Blondel B, Schwab F, Ungar B, Smith JS, Bridwell KH, Glassman SD, et al. Impact of magnitude and percentage of global sagittal plane correction on health-related quality of life at 2-years follow-up. Neurosurgery 2012;71:341–8–discussion348.
14. Akbar M, Terran J, Ames CP, Lafage VC, Schwab F. Use of surgimap spine in sagittal plane analysis, osteotomy planning, and correction calculation. Neurosurg Clin N Am 2013;24:163–72.
15. Kuklo TR. Principles for selecting fusion levels in adult spinal deformity with particular attention to lumbar curves and double major curves. Spine 2006;31:S132–8.
16. Kim YJ, Bridwell KH, Lenke LG, Rhim S, Kim Y-W. Is the T9, T11, or L1 the more reliable proximal level after adult lumbar or lumbosacral instrumented fusion to L5 or S1? Spine 2007;32:2653–61.
17. Cho K-J, Suk S-I, Park S-R, Kim J-H, Jung J-H. Selection of proximal fusion level for adult degenerative lumbar scoliosis. Eur Spine J 2013;22:394–401.
18. Polly DW, Hamill CL, Bridwell KH. Debate: to fuse or not to fuse to the sacrum, the fate of the L5-S1 disc. Spine 2006;31:S179–84. doi:10.1097/01.brs.0000234761.87368.ee.
19. Edwards CC, Bridwell KH, Patel A, Rinella AS, Jung Kim Y, Berra ABA, et al. Thoracolumbar deformity arthrodesis to L5 in adults: the fate of the L5-S1 disc. Spine 2003;28:2122–31.
20. Eck KR, Bridwell KH, Ungacta FF, Riew KD, Lapp MA, Lenke LG, et al. Complications and results of long adult deformity fusions down to l4, l5, and the sacrum. Spine 2001;26:E182–92.
21. Edwards CC, Bridwell KH, Patel A, Rinella AS, Berra A, Lenke LG. Long adult deformity fusions to L5 and the sacrum. A matched cohort analysis. Spine 2004;29:1996–2005.
22. Bridwell KH. Selection of instrumentation and fusion levels for scoliosis: where to start and where to stop. Invited submission from the Joint Section Meeting on Disorders of the Spine and Peripheral Nerves, March 2004. J Neurosurg Spine 2004;1:1–8.
23. Harimaya K, Mishiro T, Lenke LG, Bridwell KH, Koester LA, Sides BA. Etiology and revision surgical strategies in failed lumbosacral fixation of adult spinal deformity constructs. Spine 2011;36:1701–10.
24. Tsuchiya K, Bridwell KH, Kuklo TR, Lenke LG, Baldus C. Minimum 5-year analysis of L5-S1 fusion using sacropelvic fixation (bilateral S1 and iliac screws) for spinal deformity. Spine 2006;31:303–8.
25. Tumialán LM, Mummaneni PV. Long-segment spinal fixation using pelvic screws. Neurosurgery 2008;63:183–90.
26. Shen FH, Mason JR, Shimer AL, Arlet VM. Pelvic fixation for adult scoliosis. Eur Spine J 2012;22:265–75.
27. Graham RB, Sugrue PA, Koski TR. Adult Degenerative Scoliosis. Clin Spine Surg. 2016 Apr;29(3):95-107.

How to Cite this Article: Chaudhary K, Unnikrishnan R Management strategies and selection of fusion levels in adult spinal deformities.. International Journal of Spine Apr – June 2016;2(1):25-30 .

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Complications Encountered in Surgical Management Adult Spinal Deformities- Prevention and Management- A Retrospective Study in 193 Patients

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Volume 1 | Issue 1 | Apr – June 2016 | Page 21-24|Hitesh N Modi[1], Bharat R Dave[1].

Authors :Hitesh N Modi[1], Bharat R Dave[1]

[1] Department of Spine Surgery, Zydus Hospital, Thaltej, Ahmedabad, GUJ and # Stavya Spine Hospital and Research Institute, Ellisbridge, Ahmedabad, GUJ.

Address of Correspondence
Dr. Hitesh N. Modi, Department of Spine Surgery, Zydus Hospital, SG highway, Thaltej, Ahmedabad, GUJ, INDIA. Email: modispine@gmail.com

Abstract

Background: Adult spinal deformity surgery is often associated with increased number of postoperative complications. Purpose of study was to elaborate encountered complications and possible ways to prevent and avoid such complications during surgery.
Methods: This was a retrospective analytical study in 193 patients with adult spinal deformity operated between 2010 and 2014 with decompression and multilevel pedicle screw fixation. Average age of patients was 64.5 years with minimum follow-up of 12 months. Clinical results were evaluated by excellent-good, fair and poor results on regular follow-up. Complications were elaborated in detail with possible causes and ways to prevent or avoid such complications to occur in future.
Results: There were 133 (69%) patients with excellent or good results while 35 (18%) patients with fair and 25 (13%) patients with poor results. There was 24.8% (n=48 out of 193) complication rate was found in the study. There were 20, 10, 6, 5, 3, 2, 1 and1 patients had persistent symptoms, respiratory difficulty, proximal junction kyphosis, dural puncture, deaths, wound infection, foot drop and renal failure, respectively. Reason for such complications were discussed in detail and precautions implemented in future surgeries.
Conclusion: There are higher postoperative complications rates noted in adult spinal deformity surgeries. Most common complications were proximal junctional kyphosis, respiratory difficulty and persistent symptoms postoperatively. Proper preoperative preparation and precautions to avoid such complications are necessary before surgical decision.
Key Words: Adult spinal deformity, surgical correction, postoperative complications, preventive measures.

Introduction
Surgeries, in earlier phase, were developed primarily to address and treat injuries or traumas causing death if not treated. Later on, as advances in surgeries progressed, it was focused to improve quality of life. Major advances in surgeries in recent era focused on overcome obstacles of bleeding, infection and pain as well as improved quality of life and earliest return to work without any disability [1]. Therefore surgical indications are found to be an elective application, including the complex conditions such as spinal deformity that typically affect quality of life rather than being an immediate threat to life. Adult spinal deformity is a significant problem for many patients affecting their quality of life, in particularly, the elderly people. India has around 100 million elderly at present and the number is expected to increase to 323 million, constituting 20 per cent of the total population, by 2050,” the report jointly brought out by United Nations Population Fund (UNFPA) and Help Age International said. Similarly in US also the number of elderly patients has been projected to increase to 19.6% from current 12.4% by the year 2030 [2]. Spinal deformity is a major morbidity in elderly population, with pain and balance problems associated with spinal deformity often representing a significant obstacle to mobility in this age group [3]. Nonsurgical management for adult or degenerative spinal deformity is likely underreported. While it is hypothesized that a majority of spinal deformity patients are treated non operatively by their primary physicians, and increasing number of patients are opting for surgery now days [4]. Adult deformity surgery in older patients is becoming an increasingly common and requested procedure. Average life expectancy is rising with an increased expectation for extended quality of life. However, despite improved technical capabilities, complications remain a common occurrence and a significant concern in adult deformity surgery. There are many literatures published showing favorable results with adult spinal deformity surgeries; however, actual prevalence of complications varies widely [5-9]. Several reports have reported a complication rate of greater than 40% in the literature. A meta-analysis published by Yadla et al, who reviewed 3299 patients, found a 41.2% complication rate [10]. In another multicenter retrospective series of 306 primary lumbar adult or degenerative scoliosis patients older than 50, Charosky et al have shown an overall complication rate of 39% [11]. Daubs et al, in their series of 46 complex adult deformity patients aged 60 years or older, presented a complication rate of 37% [12]. In patients older than 70, Lonergan et al reported 95% of patients experiencing a complication of some type [13]. It is also important to note that variety of complications reported in literature varies in terms of minor or major complication. The purpose of this article was to identify commonly associated complications encountered during adult or degenerative scoliosis surgery, to identify and elaborate the risk factors and methods to overcome and avoid such complications. In addition we aimed at literature review of such complications to educate about it to our patients prior to surgery.

Material and Methods
This is a retrospective analytical study of 193 patients operated for degenerative or adult spinal deformity between 2010 and 2014. Average age of patients was 64.5 (SD=10.5) years (Table 1).

TABLE  1

All patients were operated by both the authors. The indications of surgery were primarily chronic mechanical low back pain, radicular symptoms, lumbar stenosis and degenerative scoliosis. All patients were explained about possible outcome with extent of surgery as well as longer recovery time than the routine. Additionally all patients were put on calcium supplementation medications prior to the surgery. All patients were operated with pedicle screw fixation and posterolateral fusion along with decompression of affected lumbar spine and correction of spinal deformity to achieve sagittal balance. All surgeries were performed with open surgical technique with wide subperisteal exposure of all operative levels till the tips of transverse processes which was followed by free-hand pedicle screw instrumentation and attempting curve correction by facetectomy with rod derogation maneuver. Decompression laminectomy with or without discectomies were performed at the only affected levels with bilateral foramina decompression. Pedicure subtraction osteotomy was performed in only indicated patients where there was gross sagittal imbalance with kyphotic deformity noted. Postoperative follow-up was done at 6weeks, 3, 6, 12 months and yearly thereafter. There was follow-up of patients apart from protocol also if there is any complication or urgent assistance needed. Results were analyzed using relief in symptoms and improvement in quality of life as well as VAS score for pain. Results were divided in to excellent and good results that had postoperative recovery in their symptoms more than 80% and 60-80%, respectively. If patient had recovery in symptoms by 40-60% and less than 40%, there were categorized in to fair and poor results accordingly. Perioperative and postoperative complications were specifically recorded and studied in detail for this study. Complications that were recorded from operative period to three months postoperative period were included in perioperative complications [14]. Complications seen after three months were included in postoperative complications. Revisions after complications were also studied separately to identify the cause.

Results and Complications
Average follow-up was 24.1 months (SD= 9.1) with minimum follow-up 12 months. There were 28 patients having at least one level listless, 69 patients with two or less level severe stenosis, and rest 96 patients having problems at more than two levels along with degenerative scoliosis (Table 1).

TABLE  1

There were 5 patients with associated dorsolumbar stenosis (tendom stenosis), one with cervical myelopathy, one with intra-dural tumor, and eight with associated compression fractures and three with discitis apart from main pathology of stenosis or instability. All pathologies were addressed and operated along with correction of degenerative scoliosis and decompression of stenotic part or stabilization of instability. Evaluation of our results at the final follow-up shows that there were 133 (69%) patients with excellent or good results while 35 (18%) patients with fair and 25 (13%) patients with poor results (Table 2).

TABLE  2

Evaluating our complications (Table 2), there were three (who were included in poor results) deaths (1.5%); out of them one was due to pulmonary embolism and rest two were due to postoperative cardiac events. There was one patient from fair results who needed hemodialysis for acute renal shut down during perioperative period which recovered after 4 weeks with 21 cycles of hemodialysis. Six (3.1%) patients were having adjacent level degeneration or implant loosening causing myelopathy symptoms that required revision surgery (Fig 1-2).

Figure 1 and 2

On further evaluating them, all of them were having severe osteoporosis of bone marrow density for wrist and hip scan. All of them were kept of Teriperatide injections for at least one year and after that they did not have any further squeals. One patient had postoperative foot drop which recovered partially over a period of three months as implant positioning were found adequate on postoperative CT scan. This patient had having severely stenotic preoprerative canal size, and therefore, reason for foot drop was mainly due to handling of roots. There were five (2.6%) dural punctures during surgery which were repaired uneventfully. There were only two (1%) patients with postoperative wound infections; one with superficial and one with deep infections. Both were healed after debridement and appropriate antibiotics. Both patients were having positive urine culture due to prolonged catheterization postoperatively. There were 10 (5.2%) patients with postoperative oxygen saturation stays below 90% mainly due to pain and obesity that decreased vital capacity. They were treated with nasal oxygen masks and active spirometry exercise without any further complications. There were 20 patients (10.4%) with persistent back pain and tingling or numbness in legs that affected their daily life infrequently. However, on further evaluating their MRI or CT scans there was no causative factors found out. They have been treated with medications, physiotherapy and reassurance. All patients were mobilized during the hospital stay with the help of physiotherapists after 24-48 hours of surgery as postoperative back pain was controlled. All patients were give training by physiotherapists for postural changes, mobilization, back strengthening exercises, toilet training and avoidance to bending forward and sitting on floor.

Discussion
Advances in pre-operative optimization, operative techniques and perioperative management have made surgical intervention a reasonable alternative for an increasing number of patients. Multiple investigators have reported substantial benefit of surgery with respect to pain, self-image, function, and ability to perform physical activities [10,15]. These benefits have been demonstrated despite the complexity of spinal realignment procedures and a substantial perioperative complication rate. There is a large body of evidence demonstrating positive mid- to long-term outcomes following surgical intervention for adult spinal deformity [16]. Yadla et al [10] found that operative intervention for adult spinal deformity is associated with improvement in both radiographic and clinical outcomes at a minimum 2-year follow-up. Similarly we have also found in our study that there was significant improvement in clinical as well as radiological parameters in our patient groups which has proven the benefits of surgery. In our study we have found overall 24.8% complications which is almost similar to the rate published in literature [1,12,13,17,18]. Postoperative deterioration in pulmonary functions in form of decrease in FEV1 is a major concern causing increased respiratory efforts and decreased oxygen saturation. There is an inevitable natural decline in pulmonary function with ageing, which may be more pronounced in patients with untreated spinal deformity [19]. Lehman et al. [20] demonstrated significant decline in all measures of pulmonary function (5-6% decline compared with predicted age-related decline) following deformity surgery with a clinically significant decline (a decline of >10% inFEV1) in pulmonary function in 27% of the patients of their series of 164 patients operated for adult spinal deformity. However, they did not evaluate immediate postoperative FEV1. In our series we have found decreased oxygen saturation and increased respiratory efforts postoperatively mainly due to obesity and post-operative pain as well as use of opioid analgesics which might cause respiratory depression. We therefore, give 30 degree prope-up position with nasal oxygen and encouragement of spirometry exercise once patient is able to follow the commands soon after surgery. With maintaining this protocol none of our patients had any long-term respiratory infections or difficulty. Additionally to start with preoperative spirometry exercise is also welcome to avoid and treat such conditions postoperatively. Proximal junctional kyphosis (PJK) or degeneration with implant loosening is also a known and well described complication in literature. In recent review article by Lau et al [17] suggested that the reported incidence of PJK ranged widely, from 5% to 46% in patients undergoing spinal instrumentation and fusion for adult spinal deformity. It is reported that 66% of PJK occurs within 3 months and 80% within 18 months after surgery. The reported revision rates due to PJK range from 13% to 55%. In our case series we have found over all 3.1% of proximal level problems and out of which we did revision surgery for five patients. One patient did not want to go ahead with revision surgery eventually developed spastic paraplegia. While other five patients who underwent revision surgery eventually improved without any further sequel. Additionally we have started Teriperatide injections to all of them to develop bone mass as their BMD suggested of having osteroporosis. Later on we have followed a protocol of starting Teriperatide injection (explained before surgery) postoperatively and maintaining that we had not found significant complications related with PJK [21,22]. Additionally we also explained our patients to avoid sitting of floor and bending forward to prevent PJK. In another review article by Soroceanu et al [23] included 245 patients to identify implant related complications after adult spinal deformity surgery. They found out 31.7% patients have had some sort of implant related complications and52.6% of those patients required reoperation. Rod breakage accounted for 47% of the implant-related complications, and proximal junctional kyphosis accounted for 54.5% of radiographical complications. In our series although we found out PJK, we did not find any patients have had complications such as rod breakage or mal-positioning of implants that needs revision. In another recent article by Sandquist et al. [24] suggested that their unique technique of multilevel segmental screw technique (MLSS) where a longer length pedicle screws was inserted from pedicle to upward direction crossing at least one or two segments to achieve stronger hold in one or two more vertebral levels; and thus decreasing chances of PJK in their series. However, we have not used this technique in any of our patients. There were other un-expected complications were also noted in our patient series such as acute renal shut down in one patient requiring hemodialysis. That patient was having hypertension as well as diabetes with renal compromise. Probable cause for ARF was identified as prolonged hypotension postoperatively has caused decreased renal perfusion resulting in to renal shut down. Therefore, we usually follow having blood pressure of minimum 100mm of Hg during surgery with constant watch on urine output. Postoperatively as well keeping Foley catheter in situ until patient starts walking and mobilizing to toilet would keep eye on volume and color of urine. If we feel color of urine is darker than what is expected, it would be always better to investigate for blood urea and creatinine level along with input output chart to correct immediately. There was one patient with acute pulmonary embolism postoperatively. Patient had long travel 24 hours before surgery with history of diabetes and previous heart disease. We then thereafter follow a protocol not to operate patients who have had long travel before 48 hours. We also investigate in form of venous Doppler study and postoperatively we also use DVT stockings to prevent such incidences unless patient starts walking independently postoperatively. We agree that this is a retrospective review study in patients with adult spinal deformity with primarily aimed at treating primary factors such as stenosis or instability along with correction of deformity. Minimum follow-up being only 12 months is also less if we wants to study all possible complications after such major surgery. However, large numbers of patient in our series is sufficient to explain and possible precautions to manage such patients postoperatively. Additionally our preoperative and postoperative precautionary steps in form of spirometry exercise, mobilization and anti DVT protocols, implementation of anti osteoporosis medications and avoidance as well as modification of life style might have prevented certain complications described in the literature. In spite of all shortcomings in the study, we think this would guide further to researchers and surgeons to keep complication rates lower after adult spinal deformity surgery.

References 

1. Smith JS KM, Crawford A, Shaffrey CI. Outcomes, expectations and complication overview for the surgical treatment of adult and paediatric spinal deformity. Spine deformity preview 2012:4-14.
2. Federal interagency forum on aging-related statistics. Older American update: Key indicator of wellness. (<http://www.agingstats.gov/agingstatsdotnet/Main_site/Data/Data_2006.aspx>) 2006; [Accessed August 8, 2011 ].
3. Bess S, Boachie-Adjei O, Burton D, Cunningham M, Shaffrey C, Shelokov A, Hostin R, Schwab F, Wood K, Akbarnia B. Pain and disability determine treatment modality for older patients with adult scoliosis, while deformity guides treatment for younger patients. Spine (Phila Pa 1976) 2009;34:2186-90.
4. Glassman SD, Berven S, Kostuik J, Dimar JR, Horton WC, Bridwell K. Nonsurgical resource utilization in adult spinal deformity. Spine (Phila Pa 1976) 2006;31:941-7.
5. Simmons ED, Jr., Kowalski JM, Simmons EH. The results of surgical treatment for adult scoliosis. Spine (Phila Pa 1976) 1993;18:718-24.
6. Deyo RA, Ciol MA, Cherkin DC, Loeser JD, Bigos SJ. Lumbar spinal fusion. A cohort study of complications, reoperations, and resource use in the Medicare population. Spine (Phila Pa 1976) 1993;18:1463-70.
7. Bradford DS, Tay BK, Hu SS. Adult scoliosis: surgical indications, operative management, complications, and outcomes. Spine (Phila Pa 1976) 1999;24:2617-29.
8. Baron EM, Albert TJ. Medical complications of surgical treatment of adult spinal deformity and how to avoid them. Spine (Phila Pa 1976) 2006;31:S106-18.
9. Burneikiene S, Nelson EL, Mason A, Rajpal S, Serxner B, Villavicencio AT. Complications in patients undergoing combined transforaminal lumbar interbody fusion and posterior instrumentation with deformity correction for degenerative scoliosis and spinal stenosis. Surg Neurol Int;3:25.
10. Yadla S, Maltenfort MG, Ratliff JK, Harrop JS. Adult scoliosis surgery outcomes: a systematic review. Neurosurg Focus;28:E3.
11. Charosky S, Guigui P, Blamoutier A, Roussouly P, Chopin D. Complications and risk factors of primary adult scoliosis surgery: a multicenter study of 306 patients. Spine (Phila Pa 1976);37:693-700.
12. Daubs MD, Lenke LG, Cheh G, Stobbs G, Bridwell KH. Adult spinal deformity surgery: complications and outcomes in patients over age 60. Spine (Phila Pa 1976) 2007;32:2238-44.
13. Lonergan T, Place H, Taylor P. Acute Complications Following Adult Spinal Deformity Surgery in Patients Aged 70 Years and Older. J Spinal Disord Tech.
14. Modi HN, Suh SW, Hong JY, Cho JW, Park JH, Yang JH. Treatment and complications in flaccid neuromuscular scoliosis (Duchenne muscular dystrophy and spinal muscular atrophy) with posterior-only pedicle screw instrumentation. Eur Spine J;19:384-93.
15. Smith JS, Shaffrey CI, Glassman SD, Berven SH, Schwab FJ, Hamill CL, Horton WC, Ondra SL, Sansur CA, Bridwell KH. Risk-benefit assessment of surgery for adult scoliosis: an analysis based on patient age. Spine (Phila Pa 1976);36:817-24.
16. Paulus MC, Kalantar SB, Radcliff K. Cost and value of spinal deformity surgery. Spine (Phila Pa 1976);39:388-93.
17. Lau D, Clark AJ, Scheer JK, Daubs MD, Coe JD, Paonessa KJ, LaGrone MO, Kasten MD, Amaral RA, Trobisch PD, Lee JH, Fabris-Monterumici D, Anand N, Cree AK, Hart RA, Hey LA, Ames CP. Proximal junctional kyphosis and failure after spinal deformity surgery: a systematic review of the literature as a background to classification development. Spine (Phila Pa 1976);39:2093-102.
18. Shapiro GS, Taira G, Boachie-Adjei O. Results of surgical treatment of adult idiopathic scoliosis with low back pain and spinal stenosis: a study of long-term clinical radiographic outcomes. Spine (Phila Pa 1976) 2003;28:358-63.
19. Weinstein SL, Zavala DC, Ponseti IV. Idiopathic scoliosis: long-term follow-up and prognosis in untreated patients. J Bone Joint Surg Am 1981;63:702-12.
20. Lehman RA, Jr., Kang DG, Lenke LG, Stallbaumer JJ, Sides BA. Pulmonary function following adult spinal deformity surgery: minimum two-year follow-up. J Bone Joint Surg Am;97:32-9.
21. Ohtori S, Inoue G, Orita S, Yamauchi K, Eguchi Y, Ochiai N, Kishida S, Kuniyoshi K, Aoki Y, Nakamura J, Ishikawa T, Miyagi M, Kamoda H, Suzuki M, Kubota G, Sakuma Y, Oikawa Y, Inage K, Sainoh T, Takaso M, Toyone T, Takahashi K. Comparison of teriparatide and bisphosphonate treatment to reduce pedicle screw loosening after lumbar spinal fusion surgery in postmenopausal women with osteoporosis from a bone quality perspective. Spine (Phila Pa 1976);38:E487-92.
22. Park JH, Kang KC, Shin DE, Koh YG, Son JS, Kim BH. Preventive effects of conservative treatment with short-term teriparatide on the progression of vertebral body collapse after osteoporotic vertebral compression fracture. Osteoporos Int;25:613-8.
23. Soroceanu A, Diebo BG, Burton D, Smith JS, Deviren V, Shaffrey C, Kim HJ, Mundis G, Ames C, Errico T, Bess S, Hostin R, Hart R, Schwab F, Lafage V. Radiographical and Implant-Related Complications in Adult Spinal Deformity Surgery: Incidence, Patient Risk Factors, and Impact on Health-Related Quality of Life. Spine (Phila Pa 1976);40:1414-21.
24. Sandquist L, Carr D, Tong D, Gonda R, Soo TM. Preventing proximal junctional failure in long segmental instrumented cases of adult degenerative scoliosis using a multilevel stabilization screw technique. Surg Neurol Int;6:112.

How to Cite this Article: Modi H, Dave BR. Complications encountered in surgical management adult spinal deformities- Prevention and management- a retrospective study in 193 patients. International Journal of Spine Apr – June 2016;1(1):21-24 .

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Osteoporosis And its Effect on Progression of Adult Spinal Deformities

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Volume 1 | Issue 1 |Apr – June 2016 | Page 15-20|H S Chhabra[1], PK Kartik Yelamarthy[1].

Authors :H S Chhabra[1], PK Kartik Yelamarthy[1]

[1] Indian Spinal Injuries Centre, Sector C, Vasant Kunj,
New Delhi, India.

Address of Correspondence
Dr. H S Chhabra
Indian Spinal Injuries Centre, Sector C, Vasant Kunj, New Delhi, India.
Email Id:-dryelamarthykarthik@gmail.com

Abstract

Adult spinal deformity may occur as the result of a number of conditions and patients may present with a heterogeneous group of symptoms. These include deformities in all 3 planes (coronal, sagital and axial) i.e scoliosis, kyphosis and rotational deformities. Clinical presentation varies and differs from pediatric deformities in that patients present more often with axial back pain and neurogenic claudication rather than a cosmetic deformity. Indications for treatment include pain, neurogenic symptoms, and progressive deformity. Larger deviations in the anterior, posterior or lateral plane will require greater energy use to maintain a standing position. Finally, progression outside of the “stable cone of economy” results in a loss of postural control and the need for external supports. The aim of this article is to analyze the role of osteoporosis in the progression of adult spinal deformity .We conducted a review of literature from Medline and searched for articles related to adult spinal deformities and osteoporosis. Osteoporosis along with progressive and asymmetric degeneration of the disc and facet joints has a role in progression of these deformities. Osteoporosis may also impact surgical options and can significantly impact the operative plan.
Keywords: Adult spinal deformity, osteoporosis, disc degeneration, deformity progression.

Introduction
Spinal deformity is defined as a curvature in the spine where the alignment is outside of defined normal limits. Adult spinal deformity is one of the most challenging spinal disorders and by definition describes a complex spectrum of spinal deformities that present in adulthood including adult scoliosis, sagittal and coronal imbalance, and iatrogenic deformity, with or without spinal stenosis [1].Adult spinal deformity may occur as a result of a number of conditions, each of which ultimately lead to an imbalance of the structural support of the spinal column. Abnormal curvature may occur in the sagittal plane (kyphosis, lordosis) or in the coronal plane (scoliosis) causing imbalance in both planes . The magnitude of the curvature of the spine is measured using Cobb angle measurements. Axial plane deformity is measured by degrees of rotation from the frontal or sagittal plane [2]. Clinical presentation of adult spinal deformity varies greatly from minimal or no symptoms to severe pain with disability [3]. A majority of patients remain asymptomatic with radiographic findings alone. However, when patients begin to complain of symptoms, these may vary from mild back pain without radiculopathy to severe back pain with neurogenic claudication, radiculopathy, and walking intolerance.4 A complete patient assessment requires not only appropriate imaging studies but a complete history and physical exam. An adult deformity classification has been established by Schwab et al and applies radiographic parameters of disability[5]. As presented in Table 1. The presented adult deformity classification has a significant impact on surgical rates and operative strategy (approach, fusion to sacrum, and use of osteotomies). Through continued investigation, further refinement of the classification and formation of effective treatment algorithms are certain to emerge to guide the care of adults suffering from spinal deformity [5].

Scoliosis: A scoliosis is diagnosed in adult patients when it occurs or becomes relevant after skeletal maturity with a Cobb angle of more than 10 degrees in the frontal plain film [6,7].

Type 1: Primary degenerative scoliosis (‘‘de novo’’ form), mostly located in the thoracolumbar or lumbar spine
Type 2: Progressive idiopathic scoliosis in adult life of the thoracic, thoracolumbar, and/or lumbar spine
Type 3: Secondary degenerative scoliosis.
(a) Scoliosis following idiopathic or other forms of scoliosis or occurring in the context of a pelvic obliquity due to a leg length discrepancy, hip pathology or a lumbosacral transitional anomaly, mostly located in the thoracolumbar, lumbar or lumbosacral spine .
(b) Scoliosis secondary to metabolic bone disease (mostly osteoporosis) combined with asymmetric arthritic disease and/or vertebral fractures

Clinically, the most prominent groups are secondary (type 3) and primary (type 1)degenerative adult scoliosis. In elderly patients, all the three forms may be aggravated by osteoporosis [8,9,10].

Sagittal Plane Deformity: Age-related postural hyperkyphosis is an exaggerated anterior curvature of the thoracic spine, sometimes referred to as Dowager’s hump or gibbous deformity. This condition impairs mobility [22] and increases the risk of falls [23] and fractures [24]. Several types of postural deformities exist according to the number, severity, and location of vertebral fractures(upper or middle thoracic, thoracolumbar, or lumbar).Satoh et al. classified osteoporotic postural deformities into the following five groups based on changes of the physiological thoracic and lumbar curvature:[11]
1) normal posture without apparent change in spinal curve;
2) round back with increased thoracic kyphosis and normal lumbar lordosis;
3) hollow round back with increased thoracic kyphosis and lumbar lordosis;
4) whole kyphosis with extensive kyphosis from thoracic to lumbar spine; and
5) lower acute kyphosis with localized lumbar kyphosis with straight thoracic spine

Iatrogenic Spinal Deformity
Iatrogenic spinal deformities can cause either sagittal or coronal imbalance. They consist of flat back syndrome, post-laminectomy kyphosis and proximal junctional kyphosis(PJK).With the development of posterior segmental stabilization, the rates of flat back syndrome decreased [12,13,14,15,16]. A pathology known as junctional kyphosis also commonly calls for the use of instrumentation above the level of fusion in the thoraco-lumbar or cervico-thoracal vertebrae . Fusions that end at the level of the 7th and 8th thoracic vertebrae are known as the apex of thoracic kyphosis and may lead to junctional kyphosis. Post-laminectomy kyphosis is mostly seen after multi-level laminectomy procedures, especially in the cervical region and in cases of facetectomies with facet capsule destruction [17]. After cervical laminectomies in pediatric patients with incomplete bone development, post-laminectomy kyphosis is seen more commonly than in adult patients [17,18]. The rate of post-laminectomy kyphosis may become much greater in the population of pediatric patients with malignant intramedullary pathologies following radiotherapy treatment [17,19].

Natural History

Adult Scoliosis:
Idiopathic curves:(type 2 curves)[20]:
Lumbar curves of more than 300 degrees with apical vertebral rotation of more than 30% progressed the most. Right sided lumbar curves tended to progress twice as much as left lumbar curves. Also, marked vertebral rotation combined with translational shift (lateral olisthesis) was associated with significant curve progression. The thoracolumbar curve pattern manifested the most pronounced amount of apical vertebral rotation. The incidence of translatory shifts increased with time. Combined curves tended to balance with age, although lumbar part tended to progress more than the thoracic counter part. Weinstein and Ponsetti noted greater progression in lumbar curve if L5 was not well seated over the sacrum and apical vertebral rotation was more than 33% [48].

De novo curves (type 1 curves)[20]:
Robin et al analysed 554 individuals longitudinally for 7 to 13 years (315 women and 239 men, age range 50 to 84 yrs). 179 had curves exceeding 100. Fifty five (10%) developed denovo scoliosis during this period. Left sided curves were common in women. Sex ratio (F:M) increased with curve size. Rotatory olisthesis was found in 34% of patients, most common at L3-4 and L4-5 levels. As per a prospective study by Korovessis et al [21], risk factors directly related to curve progression were lateral olisthesis at the apical vertebra, a high Harrington factor (Cobb angle divided by number of vertebrae included in the curve) and the disc index.

Sagittal Plane Deformity:
The natural history of hyperkyphosis is not firmly established. Hyperkyphosis may develop from either muscle weakness and degenerative disc disease, leading to vertebral fractures and worsening hyperkyphosis, or from initial vertebral fractures that precipitate its development

Cause And Progression Of Adult Deformity (scoliosis, sagittal deformity, iatrogenic deformity)

Scoliosis:
The clinical syndrome of spinal osteoporosis is characterized by the occurrence of non-traumaticvertebral fractures and a disproportionately large amount of loss of trabecular bone necessary for the maintenance of vertebral strength [25,26].
Significant correlations exist between the bone mineral content, the compressive strength of the vertebrae [27,27,29], vertebral fractures, hyperkyphosis, and back pain. What remains unresolved is the role played by decreased vertebral bone mineral content in the development and progression of scoliosis in the adult. Shands and Eisberg noted a higher incidence of scoliosis in persons over 60years of age. Later, Vanderpool et al [30] reported scoliosis in 6%of persons over 50 years, and 36%more in those with osteoporosis. Those authors noted that scoliosis can arise in the elderly and is etiologically related to the higher incidence of metabolic bone disease. In an epidemiological study of routine anteropostenor (AP) chest and recumbent roentgenograms of the lower thoracic and lumbar spine, Robin et a1 .concluded that there was no basis for assuming a causal relationship between scoliosis and osteoporosis .But several theories could explain the association between fractures and scoliosis. Fractures may cause scoliosis, or, conversely scoliosis may cause fractures. Alternatively, scoliosis and fractures may be manifestations of the same underlying condition so that they would be expected to occur together frequently. The posterior spinal elements, facet joints. and ligamentous structures are not disrupted in osteoporotic compression fractures and may provide a fixed axis for sagittal and coronal spinal deformities. Yet this explanation does not account for the rotatory component of the deformity seen in osteoporotic patients. Mechanical factors that increase the forces applied to a vertebra increase the likelihood of that vertebra mechanically failing. Theoretically, a collagen abnormality may be responsible for osteoporosis and so called idiopathic scoliosis. Thus, several independent lines of evidence support the finding of a high concordance between osteoporosis and scoliosis. Fractures in osteoporotic or scoliotic patients would result from routine loading of an inherently weak spinal connective tissue [31].

The asymmetric degeneration of the disc and/or the facet joints leads to an asymmetric loading of the spinal segment and consequently of a whole spinal area. This again leads to an asymmetric deformity. Such a deformity again triggers asymmetric degeneration and induces asymmetric loading, creating a vicious cycle and enhancing curve progression. The destruction of structural spinal elements like discs, facet joints, and joint capsules responsible for stability leads to uni- or multi-segmental, multi-directional instability and can manifest as spondylolisthesis or translational or rotary olisthesis. The biological reaction is the formation of osteophytes at facet joint and vertebral end plates contributing to increasing narrowing of the spinal canal with facetjoint and ligamentum flavum hypertrophy and calcification. Effective narrowing of the spinal canal caliber causes central and lateral recess spinal stenosis [32,33]. Instability and collapse of the disc height leads to foraminal stenosis, with radicular pain or neurogenic claudication-type pain.

The asymmetric loading, coupled with degeneration, triggers a vicious cycle enhancing curve progression. This is fueled by common metabolic bone disorders like osteoporosis especially in post-menopause female patients leading to further asymmetric deformation and collapse in the weakened osteoporotic vertebra with subsequent curve progression[34].

Table 1

Sagittal Plane Deformity:
Sagittal postural deformities begin with localized kyphosis due to either fracture or asymptomatic insidious collapse at the thoracic and/or thoracolumbar spine . This increased kyphosis (round back) can be readily compensated by increasing lumbar lordosis, resulting in the formation of the hollow round back [35]. Compensated upper thoracic lordosis for wedged vertebral fractures at the thoracolumbar junction results in lower acute kyphosis .If progressing round back cannot be compensated by lumbar lordosis, kyphosis extends down to the lumbar region, resulting in whole kyphosis. Therefore, whole kyphosis cannot be compensated by other spinal segments. Because lumbar kyphosis is thought to be related to weakness of the spinal extensors [36], whole kyphosis usually forces the patient to use a cane while standing and walking [35]. These uncompensated conditions seemed to contribute impairment of all the domain scores in the whole kyphosis group, especially in the activities of daily living domain score, resulting in a significant reduction in the total quality of life score compared with other postural deformities.

Iatrogenic Deformity:
Risk factors for PJK included age at operation, low bone mineral density, shorter fusion constructs, upper instrumented vertebrae below L2, and inadequate restoration of global sagittal balance. Osteopenia/osteoporosis has been established as a significant risk factor for proximal junctional kyphosis. Both symptomatic and asymptomatic compression fractures that kyphose the spine are not uncommon in the elderly. In addition, the elderly tend to have more kyphosis in their thoracic spine. For this reason, longer instrumented fusions that span the entire thoracic spine are often needed [37]

Implications of Deformity Progession:
In the domain of spinal surgery, it is useful to recall important concepts that can serve as a foundation to understanding and treating deformity. Optimal alignment of bone structures and joints is critical for the efficient function of the musculoskeletal system. Furthermore, a complex interaction of the neurologic system and muscular recruitment is necessary for ergonomic balance and deliberate displacement of the human body. Therefore, it is important to consider that ideal spinal alignment allows an individual to assume standing posture with minimal muscular energy expenditure. Physiologic curvatures of the spine in the sagittal plane, the straight spine in the coronal plane, balanced tension of the spinal ligaments, and activation of intrinsic anterior and posterior musculature should permit extended pain free erect position. This concept is reflected in the “Cone of Economy” principle conceptualized by Jean Dubousset [46] (Figure 1). Within the center of the cone, the individual may remain in an ergonomically favorable erect position. However, larger deviations in the anterior posterior
or lateral plane will require greater energy use to maintain a standing position. Finally, progression outside of the “stable cone” results in a loss of postural control and the need for external supports.

Figure 1 and 2

In the setting of adult spinal deformity (ASD), structural or iatrogenic modifications to spinal alignment should be considered . Spinal malalignment in ASD challenges balance mechanisms used for maintenance of an upright posture to achieve the basic human needs of preserving level visual gaze and retaining the head over the pelvis. Progressive severity in skeletal malalignment might result in greater recruitment in muscular effort and greater energy expenditure to maintain the erect posture as well as use of compensatory mechanisms. Spinal malalignment to the extremes of the “Cone of Economy” leads to extreme muscular demand, fatigue, and significant pain as well as disability. Once a spinal deformity has reached
the level of marked loss in function and quality of life, surgical intervention is often recommended and requested [46,47]

Influence of Osteoporosis on Management of Adult Deformity
The surgical treatment is complicated by the weak bone where implants are more difficult to be anchored and fixed, making the instrumented fusion prone to instrumentation-related complications. Trabecular bone is predominantly affected by osteoporosis, and because the pedicle screw has cortical contact limited to the pedicle isthmus, a “windshield wiper” mode of failure typically leads to screw loosening [38]. Therefore, fixation strategies for osteoporotic bone are targeted either toward taking advantage of the relatively stronger cortical bone [39] or toward augmenting the fixation of a pedicle screw within the existing trabecular bone [40]. It should be recognized, however, that when sclerosis is associated with degeneration in patients with adult scoliosis, the local bone mineral density may be significantly increased, limiting the local effects of the systemic osteoporosis. Various methods have been used for treatment of the osteoporotic patient, including sublaminar wires and pediculolaminar fixation [41], both of which take advantage of cortical bone composition of the posterior spinal lamina. In addition, techniques to improve the fixation of pedicle screws within osteoporotic trabecular bone have also been developed including polymethylmethacrylate cement augmentation of pedicle screws [42]. Calcium sulfate paste may also be used, which has the theoretical advantage of becoming replaced by bone over time 43. Other alternatives have been investigated, including conical screws, hydroxyapatite-coated screws, and expandable screws. There is no consensus on the optimal screw diameter, length, or shape for fixation in osteoporotic bone. It has been demonstrated that with high insertional torque, the screw-strength is improved [44]. This may be attained by undertapping (or not tapping) the screw trajectory. Larger-diameter screws may offer increased contact with the cortical bone of the pedicle and, thus, increase insertional torque. However, this may potentially increase the risk of pedicle fracture particularly in this population. Longer screw length also can increase screw pull-out strength, particularly when there is “bicortical” purchase with the distal end of the screw passing through the anterior vertebral cortex. However, bicortical purchase increases the possibility of injury to abdominal or vascular structures and therefore is usually limited to the sacral region. An additional strategy is to use multiple points of fixation with a numerous pedicle screw construct thus providing for the spread and distribution of contact forces. Care should be taken to preserve the supraspinous ligament, intraspinous ligament, and ligamentum flavum between the rostral fused level and the adjacent segment as well as throughout the construct where possible. This may possibly prevent the development of junctional deformity and instability because it serves as a segment of high posterior tension. With extension of the fusion to the sacrum, utilization of multiple and bicortical screw fixation in addition to consideration of anterior column support at L5–S1 and/or iliac fixation should be considered. Larger diameters and increased lengths to 70 or 80 mm improve iliac screw pull-out strength. This improved caudal fixation in deformity patients has been found to be persistent in patients with a minimum of 5 years of follow-up [45]. In summary, several of the central tenets of spinal reconstruction are particularly important in the adult deformity patient population with poor bone quality. Appropriate balance reduces junctional forces, which diminishes the risk of both instrumentation failure and adjacent vertebral fractures. The surgeon should thus endeavor to balance the rostral and caudal ends of the construct. In addition, a meticulous fusion procedure, augmented with appropriate bone graft or bone graft substitutes, is especially important. This will support the development of a rapid and solid fusion such that long-term spinal stability will be ensured, relieving the requirements put upon the reconstruction instrumentation and its relatively poor interface with the osteoporotic bone.

Figure 3 and 4

Conclusions

Adult spinal deformity may occur as a result of a number of
conditions, each of which ultimately lead to an imbalance of the
structural support of the spinal column. These deformities can
occur in all 3 planes. The asymmetric loading, coupled with
degeneration is fuelled by osteoporosis in the progression of
adult spinal deformities. Osteoporosis also plays a role in
deciding the instrumentation to be used in management of these deformities.

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How to Cite this Article:  Chhabra HS, Yelamarthy PKK. Osteoporosis and its effect on progression of Adult Spinal deformities. International Journal of Spine Apr – June 2016;1(1):15-20 .

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Factors Influencing Sagittal Malalignment and its Effect on Clinical Implications in Adult Spinal Deformity

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Volume 1 | Issue 1 | Apr – June 2016 | Page 5-9|Bassel G Diebo[1], Jeffrey J Varghese BS[1], Frank J Schwab[1].

Authors :Bassel G Diebo[1], Jeffrey J Varghese BS[1], Frank J Schwab[1].

[1]Department Spine Service, Hospital for Special Surgery, New York, NY, United States

Address of Correspondence
Dr. Bassel G. Diebo
Spine Service, Hospital for Special Surgery, New York, NY, United States.
Email: dr.basseldiebo@gmail.com

Abstract

Respect for the sagittal plane has been broadly published and accessible for all surgeons. Yet, suboptimal outcomes and revision cases remain highly prevalent. In this article, the authors present a case of a pleasant lady who started with a simple lumbar decompression surgery for spinal stenosis that deteriorated and then failed revision surgery, ultimately presenting with a severely disabling flatback and a remarkable spinal deformity. Her case highlights the importance of sagittal alignment in degenerative patients. Failure to appreciate the sagittal plane has a direct impact on patient reported outcomes and serious debilitating iatrogenic deformity. The maintenance of spinal alignment is not a deformity specific exercise; therefore, all surgeons should consider optimizing the sagittal plane to reduce the incidence of not only iatrogenic deformity but the burden of any spinal pathology.
Keywords: Sagittal Malalignment, adult spinal deformity, degenerative scoliosis.

Introduction
The close relationship between sagittal spinal alignment and patient reported outcomes is widely recognized [1–8]. As a result, sagittal radiographic parameters, such as the SRS-Schwab modifiers (Sagittal vertical axis: SVA, pelvic incidence minus lumber lordosis: PI-LL, and pelvic tilt: PT), have been investigated and validated in multiple spinal pathologies and patient groups. However, to date, iatrogenic causes remain an important contributor to the prevalence of adult spinal deformity. One reason for the increased incidence of iatrogenic deformity relates to the lack of correction and/or preservation of sagittal alignment when addressing focal or regional degenerative conditions. In addition to decompression and stabilization, maintenance of lumbar lordosis is crucial in avoiding the creation of deformities such as flatback syndrome [9]. The importance of the sagittal plane was originally established based on multi-center databases of spinal deformity patients; however, recent studies on patients undergoing less invasive procedures for lumbar degenerative conditions unraveled the universality of this importance. In a literature review of the last two decades, Mehta et al concluded that the sagittal parameters play a central role in the treatment of isthmic spondylolysis, spondylolisthesis, and degenerative pathologies [10]. Masevnin and Kumar et al have both demonstrated that adjacent segment pathologies are more prevalent in patients who underwent surgical correction of degenerative conditions without correcting sagittal alignment [11,12]. Finally, hypo- and hyperlordosis have been reported as risk factors for disc height reduction and facet joints arthritis, respectively [13,14]. Respect for the sagittal plane has been broadly published and accessible for all surgeons. Yet, suboptimal outcomes and revision cases remain highly prevalent [15–19]. In this article, the authors present a case of a pleasant lady who started with a simple lumbar decompression surgery and a subsequent failed revision surgery. Following a short fusion of L3-L5, the patient presented herself to the spine clinic of the senior author with a disabling flatback, an inability to walk more than 1 block, and a remarkable adult spinal deformity.

Case presentation:
History of present illness and physical examination:
This is a 70-year old Caucasian female who recently presented to the senior author’s clinic with a long history of back pain and two previous surgeries. In 2011, she had lumbar laminectomies and decompressions (L3-L5) and in 2012 she ultimately underwent a L3 to L5 instrumented fusion. Her severe (8/10) pain returned in 2013, originating in her buttock region, and traveled inferiorly through the right leg to the foot. For two years, the patient was only able to walk one block before she had to pitch forward from significant back pain and need external support. She underwent several non-operative treatments including: epidural injections, physical therapy, acupuncture, massages, and multiple nerve blocks. She is on Tramadol three times a day and one Percocet 5/325 every night. The patient stood with both sagittal and coronal malalignments (Fig. 1), was unable to toe or heel walk, and had poor tandem gait. She demonstrated right distal extremity numbness and weaknesses of both the tibialis anterior and extensor hallucis longus, but was otherwise neurovascularly intact.

Figure 1: Pre-operative anterio-posterior and lateral radiographs

Figure 1: Pre-operative anterio-posterior and lateral radiographs

Radiographic imaging:
CT scan:T12-Sacrum axial imaging revealed a mild degenerative scoliosis of the upper lumbar spine with the apex between L2-L3. Cephalad to the L3-L5 fusion, the patient had facet arthroses, a disc bulge, and central canal stenoses at T12-L1 and L1-L2. At the fusion levels, the patient had multiple degenerative discs, facet arthroses, and neural foraminal narrowings. X-Ray analysis: The patient presented with a pelvic incidence of 57°, indicating a standard pelvic morphology from a spinal perspective. Sagittal alignment analysis revealed a severe adult spinal deformity classified by the SRS-Schwab: PI-LL mismatch of 34° (++), PT of 40° (++) and SVA of 86 mm (++). Thorough analysis of the lumbar spine demonstrated a caudal (L4-S1) lordosis of 24°, L3-L5 (fused segments) lordosis of 18° and, L1-L2 (unfused segments) kyphosis of 6° (Fig. 2). The thoracic spine did not exhibit any hypokyphotic compensation (TK = 45°). Coronal x-rays revealed a 22° coronal curve (L1-L3) and a 65 mm right coronal malalignment. The full radiographic analysis is reported in Fig. 3.

Figure 2: Pre-operative sagittal radiographic analysis

Figure 2: Pre-operative sagittal radiographic analysis

Figure 3: Pre-operative segmental analysis of lumbar lordosis

Figure 3: Pre-operative segmental analysis of lumbar lordosis

Surgical planning and technique:
After discussing the treatment options, benefits, and risks, with the patient for her severe sagittal plane deformity, the decision was made to extend the fusion to T3 with pelvic fixation. The surgical strategy included a L3 pedicle subtraction osteotomy (PSO) of 35° and a L5-S1 transpedicular lumbar interbody fusion (TLIF) for an expected 10° of lordotic correction. Using dedicated software (Surgimap, Nemaris Inc, New York, NY), the surgical plan was simulated to ensure proper post-operative alignment. Patient-specific custom rods were generated and forwarded to the manufacturer to be pre-bent, ensuring an accurate execution of the surgical plan. In the OR, the reconstruction required additional T3-L2 Smith-Peterson osteotomies to afford fusion and deformity correction. At the osteotomy site, a wide laminar foraminotomy from L2 to L4 was performed and two short rods were added between these levels (Four-Rod technique), offering adequate correction and closure. Fluoroscopy confirmed that the proper correction was achieved in both planes.
Post-operative follow-up:
The patient recovered without incident, and is not only satisfied but happy with her new posture. Radiographic analysis revealed an adequate lumbar lordosis, a PI-LL within 10 degrees, a global sagittal alignment (SVA) of 36 mm, and a pelvic tilt of 28°. These are classified as (0), (0) and (+) based on SRS-Schwab classification. The lumbar coronal curve was corrected to 8 degrees and the C7PL to 16 mm to the right. (Fig 4)

Figure 4: Post-operative anterio-posterior and lateral radiographs

Figure 4: Post-operative anterio-posterior and lateral radiographs

Discussion:
There is a growing body of evidence in the literature regarding the clinical implications of sagittal spinal alignment. Over the last decade, scientific conferences are increasingly dedicating significant amounts of time and effort to raising awareness and spreading the sagittal message. The teaching today is: optimize or preserve the sagittal alignment of the spine in all spectrums of operations, from ‘simple’ one-level fusions to complex multi-planar deformity surgeries. For the management of spinal pathologies, it is no longer acceptable to perform only neural decompressions for stenosis and only fusions for stabilizing the spine. The sagittal plane, specifically with respect to lumbar lordosis, should be optimally aligned, if not already. This recommendation is valid almost regardless of the spinal etiology. To guide spinal realignment in adult spinal deformity, the key sagittal modifiers (PT, PI-LL, and SVA), with their clinically relevant thresholds, are already cornerstones for surgical correction. These parameters are also being investigated in patients with degenerative disc diseases, spondylolisthesis (degenerative and isthmic), as well as spinal stenosis. Moving beyond deformity: sagittal alignment in degenerative diseases:
In degenerative spondylolisthesis (DS), it is now established that higher pelvic incidences result in higher sacral slopes and shear stresses at the lumbosacral junction, making it a predisposing factor for DS. Moreover, Jeon et al took this a step further to conclude that degenerative retrolisthesis exists in two types, both of which are driven by sagittal parameters; one primarily resulting from degeneration in patients with low pelvic incidences, and the other secondarily resulting from compensatory mechanisms in patients with anterolistheses and high pelvic incidences [20]. Ultimately, sagittal alignment influences two out of the three features included in the Labelle classification of spondylolisthesis [21]. With regards to surgical treatment, Feng et al showed that the restoration of pelvic tilt and lumbar lordosis played important roles in the surgical outcomes of DS [22]. In other degenerative diseases, Bae et al demonstrated that patients with an upper lumbar disc herniation have significantly different sagittal profiles than patients with a lower disc herniation. In their studies, pelvic incidence and lumbar lordosis were significantly factors in determining the level of disc herniation [23)]. Thus, treatment of these pathologies is increasingly considering the sagittal plane.

Sagittal alignment in spinal stenosis:
Patients with lumbar stenosis adopt a forward compensatory bending posture to relieve the symptoms of neural compression [25,26].This malalignment pattern may be confused with sagittal spinal deformity and a loss of lumbar lordosis. Thus, there has been a recent debate on whether a surgeon should address the stenosis by decompression+/-fusion alone or with spinal realignment as well. Recent data demonstrated that decompression alone does indeed improve the sagittal profile of spinal stenosis patients. Jeon et al investigated 40 lumbar stenosis patients and followed them up to two years. In their study, patients who underwent decompressions alone had improvements in SVA, from 39 mm at baseline to 23 mm at 2 year follow up [24]. Buckland et al, in unpublished data, showed that while anterior truncal malalignment was similar between deformity and degenerative patients, pelvic tilt appeared to be a unique compensatory mechanism of deformity patients. Recently, Fujii et al showed that decompressions can improve global alignment in stenotic patients when malalignment is induced by a compensatory reduction in lumbar lordosis [27]. However, they also noticed that without corrective surgery, stenosis patients with higher preoperative malalignments (PI-LL > 21.5 and SVA > 69 mm) had residual malalignments postoperatively. This malalignment has proven to negatively impact patients reported outcomes in another study by Hikata et al [28)] In general, there is rising consensus that lumbar stenosis patients with severe sagittal malalignment (SRS Schwab SVA ++) should be assessed for a concomitant sagittal deformity and ultimately be considered for corrective surgery.
While more research is needed to establish treatment guidelines for sagittal realignment of spinal stenosis patients, it is crucial to understand that the maintenance of sagittal alignment is a must. The patient in this article deteriorated from being a spinal stenosis patient undergoing a two-level fusion to a flatback patient requiring realignment with osteotomy. This iatrogenic deformity is challenging and is commonly seen in daily practice of deformity surgeons. Based on the PI-LL formula, our patient needed approximately 50° of L1-S1 lordosis, of which 65% (32°) should be in the extreme caudal lumbar segments [29)]. However, when looking at the L1-S1 lordosis of this patient, she only had 21°. More importantly, the previously fused caudal segments were constructed with only 18°, which is a clear loss of lordosis.

Sagittal alignment: How to improve, What is new and How to be more patient-specific?
To improve our understanding of the sagittal plane, the gap between researchers and clinicians must be bridged. Feedback from surgeons in daily practice is crucial to improve the current guidelines of sagittal realignment. The ultimate goal is a personalized treatment that addresses the patient’s age, pathology, function, expectations, and spino-pelvic morphology.
Lafage et al investigated the impact of age on the spino-pelvic alignment and provided updated thresholds of PT, PI-LL and SVA [30]. The new targets for the radiographic parameters provide more “patient-specific” alignment thresholds. Their data revealed that age should be considered when determining the ideal sagittal alignment for a given patient, with older patients requiring less rigorous alignment objectives (Table 1).

Table 1: Age-adjusted sagittal alignment thresholds.

Table 1: Age-adjusted sagittal alignment thresholds.

Moreover, patient-specific instrumentation is a recent advancement in spine surgery. Surgeons can now plan their surgery and choose or construct certain instrumentations based on their patient’s morphology and alignment targets. Using the existing knowledge on the optimal sagittal alignment, these customized implants might help preserve the sagittal plane in degenerative patients. There are several factors that need to be acknowledged to achieve or maintain adequate sagittal alignment of the spine. The pelvis is a key component that must be considered. The measurement of pelvic incidence (PI) and the calculation of the mismatch between PI and lumbar lordosis are crucial in assessing the deformity magnitude when its main driver is the loss of LL. Any mismatch > 10° is associated with worse patient reported outcomes. Every surgeon needs to ensure that the surgical intervention does not alter this harmony between the spine and the pelvis [1,4]. Moreover, analysis of the compensatory mechanisms recruited by each patient is mandatory. Pelvic tilt, thoracic hypokyphosis, and knee flexion [31] are common mechanisms that need to be considered and delineated from the main driver of deformity. The surgery needs to be planned with the help of dedicated software and the plan needs to be simulated to confirm that post-operative alignment is ideal [32,33]. Finally, patient expectations, comorbidities, and their soft tissue profile are highly important aspects to consider. These are being investigated for their impact on how we treat our spinal pathology patients.

Conclusions

This article, drawing support from cases and the plethora of literature available, highlights the importance of sagittal alignment in degenerative patients. Failure to appreciate the sagittal plane has a direct impact on patient reported outcomes and serious debilitating iatrogenic deformity. The maintenance of spinal alignment is not a deformity specific exercise; therefore, all surgeons should consider optimizing the sagittal plane to reduce the incidence of not only iatrogenic deformity but the burden of any spinal pathology.

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How to Cite this Article:Diebo BG, Varghese JJ, Schwab FJ. Factors Influencing Sagittal Malalignment and its effect on Clinical Implications in Adult Spinal Deformity. International Journal of Spine Apr – June 2016;1(1):5-9.

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