Intra-articular osteoid osteoma in the femoral neck of an 18-year-old man: a case report.

Objective: This case study presents the delayed diagnosis, surgical management, and postsurgical follow-up of an intra-articular osteoid osteoma of the left femoral neck in an 18-year-old male patient with special emphasis on discussing the confusing clinical and imaging characteristics of the lesion often associated with delayed diagnosis and increased morbidity.

Clinical Features: The patient initially complained of left knee and hip pain at which time conventional radiographs were reported as normal. In magnetic resonance imaging studies, the diagnosis of intra-articular osteoid osteoma of the femoral neck was suggested; however, working diagnoses also included old posttraumatic injury, hip infection, juvenile chronic arthritis, and posttraumatic arthritis. The correct diagnosis was made 31 months after presentation based on computed tomography depiction of the lesion.

Intervention And Outcome: Pain associated with the tumor was alleviated after surgical removal with minimal loss of motion and muscle atrophy 19 months after tumor excision.

Conclusion: Clinicians and radiologists should be aware of the potentially confusing clinical and imaging findings associated with intra-articular osteoid osteoma of the hip. Early correlation between juvenile joint pain and imaging abnormalities as well as the use of thin slice computed tomography imaging could reduce the time to diagnose the lesion and prevent unnecessary morbidity.