SPINE SURGERY IN DUCHENNE MUSCULAR-DYSTRO PHY

Purpose of the study The authors present a retrospective review of 27 patients presenting a Duchenne muscular dystrophy and who were operate d for spinal deformity, with special reference to functional result an d postoperative evolution of vital capacity. Material and methods Age at surgery averaged 14. Mean scoliotic angulation was 42 degrees. A th oraco-lumbar kyphosis was present in 15 cases (kyphotic index less tha n 10 degrees). A pelvic obliquity averaging 17 degrees was associated in 19 cases. Mean pre-operative vital capacity was 56 per cent. Preope rative evolution of vital capacity was documented in 18 cases : annual rate of decrease was 4,3 per cent. Heart ejection fraction averaged 6 3 per cent in 23 cases, and was normal in 4 cases. Instrumentation was extented from D3, D4 or D5 to L5 (5 cases) or S1 (22 cases). Spinal f ixation was done in all patients by subliminar wiring with Luque rods (5 cases) or Hartshill rectangle (22 cases). Sacral fixation was done with ilio-sacral screws linked to the rectangle by Cotrel Dubousset ro ds and dominos (15 cases). Results Mean blood loss was 1750 cc. Postop eratively, 25 patients were extubated on the operative day, 1 patient at D+1, and one patient underwent a tracheostomy after one month. Scol iosis was reduced to 10 degrees after surgery and 13 degrees after 30 months follow-up, Pelvic obliquity was reduced to 4 degrees after surg ery and 7 degrees after 30 months. A good spinal balance was present a fter surgery in 20 patients; at follow-up, a coronal or sagittal imbal ance averaging 40 mm was observed in 22 patients. Postoperative evolut ion of Vital capacity was documented in 21 cases. The annual decrease rate was 6,4 per cent. Rate was higher in patients presenting a good p reoperative vital capacity (over 70 per cent) and very low In patients presenting a preoperative vital capacity under 40 per cent. 10 patien ts were deceased at review after a mean 53 months survival, at a mean age of 19. 17 patients were alive with a 50 months follow-up. Discussi on Spinal surgery in Duchenne muscular dystrophy has a low morbidity. It allows to keep sitting position to the child and to preserve qualit y of life. Surgery should be considered as soon as frontal or sagittal collapse of the spine is observed. However surgery does not result in respiratory improvement nor in life duration lengthening.