A Rare Case of Intra-articular Osteochondroma of the Femoral Neck: A Case Report

Abstract

Introduction: The osteochondroma (OC) is considered a benign tumor with long bone preference. It presents usually at the metaphyseal part of the bone, with rare cases of intra-articular origins especially in the hip joint. The presentation of such rare cases varies according to its site and mass effect, which may compress the adjacent nerves, tendon, or vascular structures. The femoral neck OC carries a higher risk of femoral head vascular injury and necrosis, as well as sciatic nerve injury, which requires careful preoperative planning and intraoperative cautions. We report a rare case of intra-articular OC in the hip. Case Report: A 28-year-old male, presented to our hospital, with complaints of right-side gluteal pain, decrease hip joint extension, and feeling of a hard mass for 2 years. The radiographic evaluation showed an osseous mass related posterior and inferior to the right femur neck, with cortical and medullary continuation, and cartilaginous cap on the magnetic resonance image. The suspicious was OC, and planned for excision and histopathological evaluation. The excision was done through lateral hip approach, and it was intra-articular with marked stretching of the joint capsule. Complete excision was done, as close as possible to the femoral neck cortex using saw and osteotomes, followed by prophylactic fixation using two cannulated screws. The histopathology reports confirm the diagnoses, and the patient started on hip range of motion and abductor strengthening exercises. Over a 4-month follow-up period the patient showed significant improvement in his hip range of motion. Conclusion: The intra articular OC of the hip is as rare presentation of the OC, which carries the risks of avascular necrosis as well as nerve compression. Clinical suspicion, proper planning, and histopathological evaluation are needed for better results. Keywords: Hip joint, intra-articular tumor, osteochondroma.