Radiographic and functional outcome after surgical management of severe scoliosis in skeletally immature patients with muscular dystrophy

Abstract

Objective: Most patients with muscular dystrophy (MD) develop progressive scoliosis after losing ambulatory status, but some cases develop severe scoliosis at a skeletally immature age before losing ambulatory status. Only a few studies have been conducted in skeletally immature patients with severe scoliosis. The purpose of this study was to assess the functional and cosmetic outcome in skeletally immature patients with severe scoliosis.

Methods: Preoperative, immediate postoperative, and final follow-up radiographs were analyzed in 10 consecutive skeletally immature patients with respect to the Cobb angle degree and the pelvic obliquity angle correction, how long the correction was maintained, and the development of the crankshaft phenomenon. In the functional assessment, the ability to sit balanced, according to the Mulcahy method, and the ability to use hands, according to the Rhyu method, were evaluated. Furthermore, the degree of subjective satisfaction was evaluated in these patients.

Results: The average age of the patients was 10.4 years, and the average follow-up period was 33 months with minimum 2 years' follow-up. All 10 patients survived and were available at the follow-up. The mean Cobb and pelvic obliquity angles were 80 degrees and 17 degrees at the time of the surgery, 31 degrees and 3.7 degrees immediately after the surgery, and 35 degrees and 4.7 degrees at the time of the final follow-up, respectively. The initial mean Cobb angle correction averaged 61%, with 78% of pelvic obliquity corrected. These corrections were maintained over time in most cases. At the time of the surgery, the mean volume of blood loss was 1111 mL, with an average operation time of 411 minutes. There were no major complications. At the time of the last follow-up, no patient showed development of the crankshaft phenomenon. The average score for the ability to sit balanced improved from 4.4 to 6.6 according to the Mulcahy evaluation method. The scores for hand use were 2.2-2.7. However, the forced vital capacity of the lungs decreased from a preoperative 48% to 46.1%.

Conclusions: These results indicate that even in very young MD patients with severe scoliosis, acceptable curve correction can be achieved and maintained with surgery. The improved pelvic obliquity and scoliosis angle stabilized the spine, freeing the upper extremities and allowing productive activities characteristic of childhood.