Progressive Knee Flexion Contractures in Adolescents with Type V Osteogenesis Imperfecta: A Case Series

Case Diagnosis: Osteogenesis Imperfecta Type V presenting with bilateral knee flexion contractures

Case Description or Program Description: This case series consists of 2 patients with type V osteogenesis imperfecta (OI), a 14-year-old female diagnosed by genetic mutation in the IFITM5 gene and a 13-year-old male diagnosed by iliac bone biopsy, both presenting to our clinic with bilateral knee flexion (KF) contractures. Initial presentation of KF contractures was at 12 years of age.

Setting: Outpatient Pediatric Specialty Hospital

Assessment/Results: Initially, the male patient presented with bilateral KF contractures of 5 degrees. Meanwhile, the female presented with a left KF contracture at an outside hospital with subsequent development of a right KF contracture at the time of presentation to our institution. Both patients are undergoing pamidronate infusions for OI treatment, while KF contractures are treated with knee immobilizers, physical therapy and range of motion (ROM) exercises. Despite these interventions, KF contractures continued to progress and are now interfering with functionality, leading to a crouched gait and decreased mobility.

Discussion (relevance): Type V OI is relatively rare and classified as a moderate to severe type of OI characterized by mild to moderate short stature, dislocation of the radial head, mineralized radioulnar interosseous membranes, limited forearm ROM, hyperplastic callus formation, white sclera and no dentinogenesis imperfecta. Transmission is autosomal dominant and caused by a mutation of the IFITM5 gene with variable expressivity and clinical heterogeneity, but de novo mutations have been reported. In recent literature, additional clinical features in OI type V have been described, including three patients presenting with bilateral KF contractures interfering with ambulation.

Conclusions: This case series supports the clinical variability and spectrum of presentation in patients with OI type V. To our knowledge, less than 5 cases of patients with KF contractures have been reported in the literature. Further treatment strategies are warranted to prevent progression of KF contractures in this population.