Orthopedic outcomes of long-term daily corticosteroid treatment in Duchenne muscular dystrophy

Objective: To document the effects of long-term daily corticosteroid treatment on a variety of orthopedic outcomes in boys with Duchenne muscular dystrophy. Methods: We reviewed the charts of 159 boys with genetically confirmed dystrophinopathies followed at the Ohio State University Muscular Dystrophy Clinic between 2000 and 2003. Charts were reviewed for ambulation status, type and duration of steroid treatment (if any), and orthopedic complications including presence and location of long bone fractures, vertebral compression fractures, and the presence and degree of scoliosis. Results: The cohort consisted of 143 boys (16 boys with Becker dystrophy were excluded); 75 had been treated with steroids for at least 1 year, whereas 68 boys had never been treated or had received only a brief submaximal dose. The mean duration of daily steroid treatment was 8.04 years. Treated boys ambulated independently 3.3 years longer than the untreated group (p < 0.0001) and had a lower prevalence of scoliosis than the untreated group (31 vs 91%; p < 0.0001). The average scoliotic curve was also milder in the treated group (11.6°) compared with the untreated group (33.2°; p < 0.0001). Vertebral compression fractures occurred in 32% of the treated group, whereas no vertebral fractures were discovered in the steroid naive group (p = 0.0012). Long bone fractures were 2.6 times greater in steroid-treated patients. Conclusions: Although boys with Duchenne muscular dystrophy on long-term corticosteroid treatment have a significantly decreased risk of scoliosis and an extension of more than 3 years9 independent ambulation, they are at increased risk of vertebral and lower limb fractures compared with untreated boys.