Operative treatment of scoliosis in proximal spinal muscular atrophy: results of 41 patients.

INTRODUCTION: The early development of progressive scoliosis with pelvic obliquity is the most significant orthopaedic problem for non-ambulatory children with spinal muscular atrophy (SMA).

PATIENTS: 24 SMA patients were operated on for scoliosis using the ISOLA(®) system and 17 patients using a telescopic rod. The average age at spinal surgery was 12.3 years (6.5-22.7) in the ISOLA(®) group and 6.7 years (4.8-10.9) in the telescopic rod group.

RESULTS: The Cobb angle was corrected on average from pre-operative 83°(54°-120°) to post-operative 39°(5°-70°) in the ISOLA(®) group and, respectively, from 62°(28°-86°) to 18°(0°-34°) in the telescopic rod group. Mean loss of correction at mean follow-up of 6 years (3-10) was 6°(0°-33°) in the ISOLA(®) group and at mean follow-up of 8.6 years (3-12) 13°(0°-49°) in the telescopic rod group excluding the patients with rod failure. The vital capacity is not worsened by these operations in comparison to the natural course. After telescopic rods were implanted, there were some unsatisfactory results due to crankshaft phenomenon and an increase of pelvic obliquity.

CONCLUSION: Our recommendation for non-ambulatory SMA patients is to have definitive stabilisation using multisegmental instrumentation, starting from the age of 10 to 12 years.