A retrospective cohort of 254 patients with Osteogenesis Imperfecta (OI) had 489 upper limb radiographs available for review. Seventeen percent of the radiographs exhibited either subluxation 8% or dislocation 9% of the radial head. Type V had the highest incidence of dislocation at 58% and subluxation at 28%, while the other types had a lower range of dislocation 0-9%, and subluxation 0-29%. Posterior radial head subluxation was most prevalent in all types of OI except Type V which was more frequently displaced anterior, lateral or anterolateral. Other associated anomalies included a calcified interosseous membrane or a dysplastic capitellum, radial head or neck. Bowing deformities of the humerus and forearm bones were noted in 87%. Ulnar bowing was noted in Type V OI patients with radial head dislocation in 8 of 19 and 7 of 9 limbs with radial head subluxation. Functional hand grip strength and forearm supination and pronation motion was evaluated in 47% of patients. Grip strength was significantly reduced in Type V OI patients without radial head dislocation. Range of motion was also significantly reduced in Type III and IV, but not in Type V.
Treatment recommendations cannot be offered based on this study, but Type V patients have a higher incidence of radial head malalignment and associated defects of the radial head, neck, and capitellum as well as calcifications of the interosseous membrane suggesting a more recalcitrant spectrum of disease.