ESPE Abstracts

Introduction: Osteogenesis imperfecta (OI) is a genetic disorder affecting connective tissue, characterized by decreased bone density, spontaneous fractures, and non-bone manifestations including dental anomalies, blue sclerae, hearing impairment, and joint hypermobility. While tendon ruptures are commonly associated with various systemic conditions, occurrences related to OI are less frequent. Patellar tendon (PT) rupture, particularly, is exceptionally uncommon. Herein, we present a case report of a patient with OI who experienced an avulsion fracture of the tibial tuberosity (TT) and PT rupture following minimal trauma.

Case: A 14-year-old male patient with a confirmed diagnosis of OI presented with left knee pain and swelling subsequent to a trip and fall. His medical history included four prior fractures: the initial fracture occurred at 1.5 years old in the left tibia due to a fall, followed by fractures at 2.5, 5, and 6 years old in the right femur, all necessitating surgical intervention. Biphosphonate therapy was initiated at 2.5 years old concurrently with surgical management. The patient underwent a total of 12 cycles of biphosphonate therapy, administered at a dosage of 1 mg/kg/dose over three consecutive days per cycle. Treatment was terminated at age 7 after the last fracture occurrence. Comorbidity evaluations, including hearing, dental, and cardiac assessments, revealed no abnormalities. The patient maintained regular clinical follow-ups and was independently mobile, engaging in routine physical activity, supplemented with 600 IU of vitamin D daily. Physical examination revealed a weight of 42.5 kg (-1.5 SDS), height of 158.3 cm (-0.9 SDS), and a body mass index of 16.9 (-1.4 SDS), blue sclerae, left knee tenderness with a positive straight leg raise test. Magnetic resonance imaging confirmed a fracture of the tibial tubercle and a rupture of the patellar tendon. A L1-L4 DXA Z score was -3.49 SDS for height age and -1.77 SDS for chronological age. Orthopedic intervention involved primary repair of the tendon, followed by a six-week period of postoperative immobilization.

Conclusion: In addition to bone fractures, it is noteworthy that patients with OI may also present with rare yet clinically significant complications such as tendon ruptures.

Keywords: Osteogenesis imperfecta, patellar tendon, bone, rupture