| Abstract|| |
Over an 8 years study period, the author had an opportunity to evaluate a large number of patients with complex thoracic and thoracolumbar deformities of varied etiology. Of these 127 were treated surgically [scoliosis: 78 and hyperkyphosis :49]. These deformities were operated for a variety of indications, viz: relentless progression, risk of future neurological deficit, progressive cardiorespiratory compromise, and cosmesis. The various etiologies of these cases, along with their treatment protocols have been analyzed and presented in this paper. Various approaches and implants that we used in the surgery of these patients have also been discussed.
A specific protocol for management was devised based on the following variables:
- The etiopathology of the deformity and its natural history [viz: idiopathic, congenital, neuromuscular, nerofibromatosis, etc].
- The timing of surgery.[emergency, semi- elective, elective, etc],
- The appropriate surgical approach [anterior, posterior or combined]
- The fusion: the technique, the mandatory fusion levels, choice of grafts and bone substitutes if any?
- The postoperative protocol for mobilization and role of bracing.
- The safety factor: surgery for complex spinal deformities although rewarding is extremely "high risk" and could result in unforgiving neurological compromise either transient or permanent. This specific factor needs to be extensively discussed, preoperatively, with the patient and his family in the true context of the risk benefit ratio, before assuming responsibility for its management. Use of pre and intraoperative spinal cord monitoring [somatosensory evoked potentials] has been extremely helpful in this regard.
|How to cite this article:|
Bhojraj S Y. Evaluation and management of complex spinal deformities in developing countries - a critical analysis of 127 operated cases. Indian J Orthop 2002;36:262-6
|How to cite this URL:|
Bhojraj S Y. Evaluation and management of complex spinal deformities in developing countries - a critical analysis of 127 operated cases. Indian J Orthop [serial online] 2002 [cited 2019 May 21];36:262-6. Available from: http://www.ijoonline.com/text.asp?2002/36/4/262/35949
| Introduction|| |
Spinal deformities have always been a great challenge to spinal surgeons. Not only their treatment modalities, but also the geographic and racial incidence, causative factors, biomechanics, pathology and natural history, have all been quite perplexing to us. As more data gets added on to world literature, newer hypothesis are developed, and many get accepted as the 'final solution', only to be replaced by another theory, soon. ,,,,,,,,,
As is clear from our experience, concepts in scoliosis management are constantly being updated, and are very much 'society dependent'. The same treatment may not be valid in all situations. Hence statistics from local settings become vital in deciding management protocols.
In the following text, we present our experiences and figures pertaining to surgical management of spinal deformities. The significance of our work is in its exclusively 'Indian' stance, which makes it relevant to every orthopedic surgeon dealing in spinal deformities in our country.
| Material and Methods|| |
One hundred and twenty seven patients were operated between 1993 and 2001 at our Spine Clinic, and all have been meticulously followed up till date. There were 78 ases operated predominantly for scoliosis, and 49 cases for hyperkyphosis, though many of these had a combination of both deformities.
Out of the total 78 cases of scoliosis operated by the clinic during these 8 years, 44 were idiopathic, 16 congenital, 11 neuromuscular and 7 were dystrophic curves due to neurofibromatosis. The average follow up of these cases has been 4 years.
Preoperative assessment included measurement of Cobb angles, decompensation, documentation of rib humps, shoulder asymmetry and height / arm spans. Standing and lateral bending antero-posterior radiographs, and standing lateral radiograms were performed in all cases. MR scans were reserved in special situations to include obvious clinical evidence of congenital curves - limb length discrepancy, spina bifida variants, etc, neurofibromatosis, neuromuscular scoliosis and any curve with rapid unexplained progression. MR scans helped detect cord anomalies like diastometamyelia, Arnold Chiari malformation More Detailss, syringomyelia and tethered cord.
A single posterior approach was used for surgery in 35 cases, an anterior approach in 12 cases and the remaining 31 cases had a combined anterior and posterior approach in a single sitting.
Although 8 of these 78 cases had a non instrumented fusion or decompression, the remaining 70 cases had some form of locally made [not imported] spinal instrumentation, viz: Harrington rods with sublaminar wires in 49, closed loop spinal rectangles with sublaminar wires or pedicular screws in 7, rods with hooks and screws [hybrid] in 3 and anterior vertebral body screws [Zielke design] in 11 [Table 1].
Local rib and iliac crest bone grafts were used in all the cases. In many (n=15) of the recent cases bone graft was augmented with hydroxyapatitie blocks (Indian).
Postoperative protocol included the following:
- All cases were kept in bed until removal of skin clips i.e. 10 days post operative.
- In all cases, (excepting the 3 idiopathic curves corrected with a closed loop rectangle and sublaminar wires), a full contact thoraco lumbar, plastic- moulded posterior orthosis with anterior canvas straps was used during ambulation for a period of 3 months post operative.
- The 3 idiopathic curves, in which a closed loop rectangle and SLWS were used as instrumentation, were ambulated on the 7th post operative day without bracing.
- Activities of daily living, included schooling was restricted for a minimum of one month, depending upon the nature of the curve, instrumentation and social back up for the patient.
- Clinical radiographic evaluation was performed at 10 days, 6 weeks, 3 months then 6 monthly up to 2 years post operative and then a one yearly.
- Radiological assessment included measurement of Cobb angles, and assessment of fusion. Clinical assessment included evaluation of decompensation, cosmetic corrections and function.
Results:Following the above mentioned protocol, we generally had good results in view of deformity connection, maintenance of correction , instrumentation, fusion and long term function. One hundred and twenty seven patients were operated between 1993 and 2001 at our Spine Clinic, and all have been meticulously followed up till date. We came across a few complications in our series, including
- Implant related - minor - wire cut out, hook pull
- Implant related - minor - wire cut out, hook pull out, screw breakage
- Implant related - major - rod breakage with loss of correction
- Curve related -'Adding on' and decompensation
- Fusion related - delayed fusion / pseudarthrosis.
- Junctional kyphosis
- Neurological deficit -We had one major neurological mishap related to anterior intra canal screw penetration. No other case had any neurological compromise post operative. In this, we would like to mention that in our fairly large number of cases of sublaminar wiring, we had no wire related problems, and we feel that the risk of sublaminar wiring has been overstated in literature.
Out of the total 49 cases of thoracic and thoracolumbar hyperkyphosis operated in the clinic during these 8 years, 26 were due to spinal tuberculosis-[either active or healed] whereas the remaining 23 were due to varied etiology, viz: congenital, developmental, neuromuscular, post tumor excision/irradiation and neurofibromatosis.
These deformities were divided into 2 major categories: viz:
Category "A" were those with a localized angular apex as commonly seen in post tuberculous, congenital [hemivertebra ]etc.
These were further sub classified into:
Category "B" were those with a rounded type or a "c" shaped curve as commonly seen in neuromuscular, developmental and some cases of extensive neurofibromatosis.
- Category "A-1" with a mobile-flexible apex, as in acute-wet spinal infections
- Category "A-2" with a fixed-rigid apex as in healed spinal infections or as in congenital deformities.
Protocol for surgical approach
This particular categorization was vital to the planning of surgical approach, as follows:
Category "A-1"; required stage one posterior corrective instrumentation with closed loop spinal rectangle and sublaminar wires,[ at least 3-4 levels above and below the apex], and extensive posterior fusion followed by stage two [under the same anaesthesia] anterior debridement/clearance and strut bone grafting for long term arthrodesis and maintenance of correction.
Category "A-2" required stage one posterior "transpedicular" or "posterolateral" apical release "osteotomy" and corrective instrumentation with closed loop spinal rectangle and sublaminar wires,[ at least 3-4 levels above and below the apex], and extensive posterior fusion followed by stage two [under the same anaesthesia] anterior debridement/clearance and strut bone grafting for long term arthrodesis and maintenance of correction.
Category "B" required stage one multiple level releases comprising of discectomies with or without osteotomies and interbody multisegmental fusion using cortico-cancellous chips followed by stage two [under the same anaesthesia] corrective instrumentation with closed loop spinal rectangle and sublaminar wires, [at least 3-4 levels above and below the apex], and extensive posterior fusion.
Results: This unique, indigenous and categorized surgical approach for "correction of hyperkyphotic deformities" based on this novel classification is not described previously in world literature and has shown encouraging long term results at recent follow ups.
We have not had any major complications like implant failure leading to curve collapse, or neurological deficits post correction.
However, prominence of the upper end of the implant has been a problem in a few cases on long follow up, and we attribute this to the inter spinous dissection without stabilization of the upper most segment. We have tried to address this by reconstructing the posterior column stability by inter spinous wiring in recent cases, with a good short term result.
| Discussion|| |
We feel that surgical correction of spinal deformities is a high demand proposition with high risks involved not to maintain high costs. An institutional back up is essential to provide the 'team effort' required for this major under taking. Each deformity comes with its individual set of problems and solutions and hence generalization of protocol is not possible.
A detailed analysis of each curve and careful planning is advocated before surgery. This involves an in-depth study of the X- rays to look at curve type, flexibility and decide on the levels of fusion, and type of instrumentations. The King's classification gives good basic guidelines for tharacolumbar curves, and we have used it extensively where applicable in our series.
Choosing fusion levels
As 80% of our work is based on posterior surgery, following the Harrington's stable zone principle is imperative. This sometimes entails taking one or even 2 extra levels in the fusion, as compared to anterior surgery. However, this need not necessarily have any clinical relevance.
Lateral bending films become important in choosing the upper and lower ends of fusion in anterior surgery. It is possible to save motion segments in the anterior approach and hence we have used it mainly for pure lumbar curves, in our series where motion segments are an issue.
Role of instrumentation
The invasion of the developing countries with multinationals has increased the problems rather than solving them. Loads of implants and instrumentation systems, some of them discarded by the developed nations after prolonged use, are being dumped in our country and certain vulnerable surgeons are unfortunately falling prey to this ploy, there by making the poor patient pay for these implants which is not only very difficult to use and prohibitively expensive, but also totally unnecessary. In our series, we have had comparable immediate and long term results with cheap and simple, locally made implants and this highlights the fact that appropriate surgical technique is much more crucial than the type of implant used.
As we see it, spinal implants in deformity surgery have two basic functions - achieving correction intra-operatively, and maintaining the correction until fusion occurs, ie, 12 to 24 months. This is unlike arthroplasty, where the surgery lasts as long as the implant. Hence, implants made from expensive metal have little advantage over standard stainless steel implants.
As regards ability for correction, we have, over the years, been extremely satisfied with the correcting ability of sublaminar wires coupled with a Harrington rod or a closed loop rectangle. These not only allow translation in a staged manner, but also bring about derotation, as we have documented in post operative CT scans. These simplistic devices cost but a small fraction of what their imported counterparts do.
Clearly, there can be no substitute for a meticulous technique of release and fusion, which will assure a lasting surgical result.
Role of spinal cord Monitoring - the 'Safety Factor'
Undoubtedly, the biggest risk involved in these surgeries is the risk of inflicting neurological damage due to manipulations during surgery. Though one can never be too cautious to this end, we certainly advocate the use of spinal cord monitoring during surgery, as a back up to the surgical exercise. We use SSEP (somatosensory sensory evoked potential) at our institute, which is a real time functional tracing of the sensory tracts during surgery. Though restricted to the sensory tracts, we have found it to be extremely effective, with almost no false positive or false negative results. We have used this in all our cases. Use of epidural electrodes makes the tracing more sensitive, especially in cases with poor pre operative conduction.
Addition of motor tract monitoring would enhance our armamentarium, though we have still not used it.
The policy of 'wait and watch'
Supervised neglect could be hazardous in certain cases where early prompt and timely intervention, of a relatively innocuous nature could have avoided a much more complex and risky surgery. Hence, the message would be, that if one feels unsure about the management protocol of a particular vexing problem, one should not deny the patient an expert second opinion! In today's world of medico legal and negligence awareness the doctor may not be excused for denying timely surgical intervention for a patient with a progressive spinal deformity.
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S Y Bhojraj
Spine Clinic, PD Hinduja National Hospital, Veer Savarkar Marg, Mumbai 400016
Source of Support: None, Conflict of Interest: None