The clinical orthopedic effects of chronic daily corticosteroid treatment were evaluated by chart review in boys with genetically confirmed Duchenne muscular dystrophy (DMD) followed at the Ohio State University Muscular Dystrophy Clinic between 2000 and 2003. Becker dystrophy cases diagnosed in 16 were excluded. Of 143 with DMD, 75 (52.4%) had been treated with steroids for at least 1 year (prednisone 0.75 mg/kg/day or deflazacort 0.9 mg/kg/day), and 68 (47.6%) had never been treated or had received brief trials of subtherapeutic doses (5 mg prednisone daily for < 6 months). Both cohorts had a mean height below the 5th percentile. Mean age of the treated group was 16.9 years (range 6.1-30.5 years) vs 14.4 (1.1-39.6 years) for untreated patients. Reason for non-treatment was invariably parent fear of side effects. Mean duration of steroid treatment was 8.04 years (range 1-18 years). Independent ambulation was lost at 12.52 +/- 3.02 years for steroid-treated vs 9.21 +/- 1.48 years in untreated patients (P<.0001). Lower limb fractures accounted for loss of ambulation in only 1 case (3.1%) in the untreated group compared to 11 (40.7%) of the steroid-treated patients. Scoliosis of >10 degrees developed in 31% of treated vs 91% of untreated (P<.0001). Vertebral compression fractures occurred in 32% of steroid-treated and none of untreated patients (P=.0012). The prevalence of femoral fractures was 28.3% in treated vs 7.27% in untreated patients (P.0051). Humeral fractures were less frequent in steroid-treated (9.43%) compared to untreated patients (25.45%) (P=.042). 
COMMENT. Long-term treatment with steroids in DMD patients results in an increase in duration of independent ambulation of more than 3 years and a significantly decreased risk of scoliosis. Adverse effects include a vertebral compression fracture in one-third of steroid-treated patients, although 80% are asymptomatic and are discovered incidentally at scoliosis screening. The risk of long bone fracture is 2.6 times greater in treated compared to untreated patients. The increased fracture rate is linked to prolonged independent ambulation and increased body weight. All treated patients are prescribed calcium supplements and have bone density measurements.