TREATMENT OF NEUROLOGICAL SCOLIOSIS OF MORE THAN 100° BY USING AN HYBRID CONSTRUCT (PEDICLE SCREWS PLUS UNIVERSAL CLAMPS)

Abstract

Neurological scoliosis differs from idiopathic type for some peculiar features that negatively affect operative time and blood loss during surgical treatment. To reduce the rate of complications in neurological scoliosis, an hybrid construct based on combined lumbar pedicle screws and Universal Clamps (UC) at thoracic levels can be used. The aim of our study was to assess the validity of the hybrid construct in neurological scoliosis treatment respect to technical success (deformity correction), operative time and blood loss, in a prospective series of patients with preoperative Cobb angle > 100°. Between 2002 and 2008 we treated 15 patients (3 M, 12 F) affected by neurological scoliosis with preoperative Cobb angle > 100° (107±4°) by hybrid construct. The mean age was 14 years (range 10–17). The etiology was cerebral palsy in 12 cases, Friedreich’s ataxia in 2 cases and Aicardi Syndrome in one case. All patients were treated by posterior access to stabilize each affected level, combining screws (Socore TM), UC and hooks in an hybrid construct. In 3 patients a secondary posterior access was achieved in order to strengthen the UC effect, adding a concave costotomy. Skull traction by sling and pelvic countertraction to control obliquity were used in all cases. Pelvic instrumentation provided iliosacral screw fixation according to Dubousset or iliac fixation in accordance with Sponseller. Two concave rods and one convex were used in all assembly. The average percentage of correction was 70% (32±7°). Mean operative time was 4 hours with mean blood loss of 1800 ml. We used a mean of 6 transpedicular screws (range 4–11), 7 UC (5–9) and 5 hooks (4–6) in our assembly. Mean follow-up time was 36 months (range 12–84), with an average loss of correction of 7°. The hybrid construct (lumbar transpedicular screws, thoracic Universal Clamps, pedicle-transverse hooks at the upper end of the curve) appears safe and effective in treatment of neurological scoliosis > 100°. This assembly provides a good correction of the deformity and reduces operative time, radiation exposure and blood loss respect to all-screws constructs. Sublaminar acrylic loops (Universal Clamp) have the same stress resistance in comparison with steel or titanium alloy sublaminar wires. Moreover, the simplicity of implant and tensioning of the strips is associated with the possibility of re-tensioning and progressive correction, providing a better capacity of managing the kyphotic component in case of thoracic lordosis. Among neurological scoliosis treatments, the hybrid construct can be considered a valid option due to the advantages of shortening the operative time and diminishing the risks of vascular and neurological complications.