A Case Report of Osteochondritis Dissecans in a Rare Location: The Lateral Femoral Trochlea.

Objective: The purpose of this case report is to describe a rare location for knee osteochondritis dissecans (OCD).

Clinical Features: A 28-year-old man presented to a chiropractic clinic with left posterolateral knee pain and swelling with joint locking after falling asleep with knees bent. A history of knee locking was reported by the patient. At presentation, he demonstrated the inability to straighten his left knee. On a pain scale of 1 to 10, he experienced level-8 stabbing pain during all knee ranges of motion with radiation to the foot. The patient was suspected of deep vein thrombosis and was sent to urgent care for evaluation.

Intervention and Outcome: Deep vein thrombosis was ruled out, and additional knee imaging was obtained at our clinic. Left knee radiography and diagnostic ultrasound revealed a lateral femoral trochlea osteochondral defect with an associated osteochondral fragment. Magnetic resonance imaging of the left knee was obtained for further evaluation and confirmed the diagnosis of OCD. The patient underwent surgical treatment for loose body removal and trochlear chondroplasty.

Conclusion: The diagnostic imaging findings in this case revealed a rare location for OCD, the lateral femoral trochlea. Symptoms of posterior knee pain require careful evaluation by clinicians and radiologists to ensure timely diagnosis and optimal treatment.