Description and Treatment of an OCD Lesion of the Proximal Groove and Medial Ridge of the Femoral Trochlea in a Dog

Abstract This report describes a hitherto unreported site of stifle osteochondritis dissecans, its surgical treatment and functional outcome. A 7-year-old male Belgian Shepherd with a history of grade 2 left hindlimb lameness of 4 months duration, presented with moderate left hindlimb lameness associated with mild muscle atrophy, stifle effusion and discomfort at stifle manipulation, without any associated instability. Radiographs showed an irregular defect on the proximal part of the femoral trochlea associated with subchondral sclerosis. Arthroscopic findings were consistent with an osteochondritis dissecans lesion of the groove and axial side of the medial ridge of the femoral trochlea and confirmed by histopathological analysis of the removed fragment. Treatment included removal of the osteochondral fragment, debridement and picking of the lesion bed. Four months of follow-up revealed improvement of the lameness despite a persistent slight discomfort in full stifle extension with associated joint effusion. Concurrent magnetic resonance imaging and arthroscopic recheck showed thin fibrocartilage partially covering the treated lesion without any sign of synovitis, with no other stifle injury. Eight months postoperatively, the owners reported satisfactory limb function. This is the first report of stifle osteochondritis dissecans localized in the proximal groove and axial side of the femoral trochlea, successfully treated surgically.