A clunking knee with an unusual cause in an adolescent: a case report.

The authors report an unusual case of a chondral lesion in the knee joint in an adolescent. The lesion produced a clunk in the knee joint on flexion. A low-resolution MRI scan failed to image the lesion. Arthroscopy revealed a unique shape of chondral flap from the weight bearing surface of the lateral femoral condyle, which resembled a meniscal bucket handle tear. Chondrectomy resolved all the symptoms. This case report highlights the point that special resolution MRI scan sequences are required to accurately assess these injuries and also that clunking in an adolescent can be produced by a chondral lesion.