Abstract
In spite of preventive treatment, particularly in young paraplegics with transverse lesions above T9, a high rate of neurogenic scoliosis must be expected. Due to the loss of sitting balance in the wheelchair, to increased risks of pressure sores, and to progressive restriction to the patient’s ventilatory function, surgical intervention often becomes necessary. A surgical method for successful application in SCI patients should meet specific demands:
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High primary stability: External immobilisation in braces or casts would pose problems, long-lasting bed rest must be avoided and no muscular support is possible. Conversely, the instrumentation must resist against often very strong spinal spasticity.
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High corrective capacity in all planes: Wheelchair dependent patients have fewer facilities for compensation of a remaining spinal deformity than ambulating patients. In sub-optimal correction, the sacrum has to be included into the fusion more frequently, with serious impact on the patient’s independence in ADL.
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Avoidance of precedent procedures for anterior release: The ventilatory function in patients with mainly high thoracic or cervical transverse lesions is already impaired, let alone the effect of the scoliosis. Additional impacts by thoracotomy should be avoided if possible. The same aspect should also be considered, looking at the following.
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Posterior procedure: Because neurogenic scoliosis deformities usually need long instrumentations, exclusively anterior procedures can rarely be used. Compared with the combination of anterior (e.g. thoracic VDS) procedures together with a posterior method, a purely posterior procedure would be beneficial, as long as it can achieve equal correction.
Since 1991 the author has worked on a concept using pedicle screws as cantilevers for 3-D correction, de-rotation being the core manoeuvre. The evolutive development of suitable, outrigged instruments for the reduction has now been finalised, allowing the presentation of the method.
Although more than 20 cases have demonstrated the method’s superior potential in 3-D correction of the deformity, and although the primary stability provided by the method meets the requirements of this patient group, neurogenic scoliosis in para- and tetraplegics still poses inherent problems:
• Insertion of pedicle screws in scoliosis is difficult, at least in the upper thoracic region. It will take time before sufficiently accurate and available modern navigation systems can resolve this.
• Once the lumbosacral junction is included in the fusion, negative impacts on the patient’s ADL, as well as on the fusion rate, must be anticipated.
In conclusion, a promising and effective method for surgical correction of neurogenic scoliosis is available.
The use of this method will become easier by further developments in computer assisted surgery. Having a tool at hand, which, by it’s corrective abilities, allows the sparing of the lumbosacral junction from fusion, as long as pelvic obliquity is not fixed, the detection of initial fixation by thorough follow up of the patients at risk becomes paramount.
The abstracts were prepared by Mr Peter Millner. Correspondence should be addressed to Peter Millner, Consultant Spinal Surgeon, Orthopaedic Surgery, Chancellor Wing, Ward 28 Office Suite, St James’ University Hospital, Beckett Street, Leeds LS9 7TF.
