Early treatment of scoliosis with growing rods in children with severe spinal muscular atrophy: a preliminary report.

BACKGROUND: Spinal muscle atrophy (SMA) is a progressive neuromuscular disease predominantly presenting in infancy and early childhood. Scoliosis is the most common spinal deformity in these patients and treatment in SMA patients is controversial. Treatment is usually definitive fusion. The purpose of this study is to evaluate a novel growing rod technique used to treat more involved children with SMA types I and II with scoliosis at an earlier age.

METHODS: An Institutional Review Board approved retrospective medical record review was performed of children with SMA who were treated for scoliosis with the growing rod construct. Chart and radiographic data were reviewed. Eleven patients met the inclusion criteria, 4 male and 7 female patients. No patients were lost to follow-up. Mean follow-up was 43 months (range, 24 to 76 mo). The average age at time of surgery was 6 years. Five patients had a diagnosis of SMA I, 6 patients with SMA II. The 11 children underwent 45 surgical procedures, 12 growing rod implantations with 34 lengthenings.

TECHNIQUE: 4.5 mm titanium rods (Medronic Memphis, TN) were implanted obtaining a stable anchor point proximally with 4 pedicle screws and a cross link, and distally with 2 iliac bolts and 2 pedicle screws. Fusion is obtained at both anchor points by decortications and the use of bone graft. Subcutaneous low profile rods span between both anchor points using axial connectors.

RESULTS: The average preoperative Cobb angle measurement of the major curve was 51.5 degrees (range, 38 to 76 degrees), postoperatively, 21.6 degrees (range, 2 to 34 degrees), and follow-up 18.7 degrees (range, 5 to 34 degrees). No surgical complications were identified or unplanned return to surgery. Medical complications were seen in 2 patients for postoperative pneumonia and anemia.

CONCLUSIONS: Growing rod construct is an effective option in the treatment of scoliosis in SMA patients with scoliosis.