Effects of withdrawal of bracing in matched pairs of children with osteogenesis imperfecta

Abstract

Objectives: To evaluate the effects of withdrawal of long-leg braces (hip-knee-ankle-foot orthoses [HKAFO]) on activity and ambulation in children with osteogenesis imperfecta. Design: A prospective, randomized cross-over trial, that describes the effects of withdrawing HKAFO. Patients: Ten children who were ambulatory with the assistance of braces. All had type III or IV osteogenesis imperfecta. Children were paired for age and clinical severity. Strength testing, fractures, and independence in daily activity were monitored at 4-month intervals for 32 months (16 months each of braced and unbraced periods). Gait was analyzed during braced and unbraced conditions. Results: Muscle strength declined .35 grade during unbraced and .1 grade during braced intervals. Children spent more time in upright activity during braced intervals than during unbraced intervals ( p = .17). Children were more independent in daily activities during braced than during unbraced periods ( p = .14). Seventeen fractures of lower extremities occurred during all the unbraced periods, and 8 occurred during the braced intervals ( p = .08); the fracture rate was higher during unbraced intervals. ( p = .06) Bracing was associated with increased hip flexion and stride length and decreased transverse plane pelvic rotation. Conclusion: Withdrawal of HKAFO in children with osteogenesis imperfecta who had achieved upright activity was not associated with significant decrease in muscle strength or independence, but there was an associated increase in fracture rate that nearly reached significance.