Outcome after arthroscopic treatment of lateral femoral trochlear ridge osteochondrosis in sport horses. A retrospective study of 37 horses.

OBJECTIVES: To determine the short- and long-term outcome for sport horses after arthroscopic treatment of osteochondrosis of the lateral trochlear ridge of the femur. METHODS: A retrospective study was performed using the medical records of horses intended for use as English sport horses. Outcome was obtained through telephone questionnaire. RESULTS: Thirty-seven horses, mainly Warmbloods, underwent arthroscopic surgery for treatment of lateral femoral trochlear ridge osteochondrosis. Short-term outcome revealed that 27 of 37 horses had no complications. Seven horses had postoperative lameness and effusion which eventually resolved in four horses. Long-term outcome was available for 29 horses, of which 19 were performing to full expectations. Five horses were athletic but at a lower level than expected, and five horses were unable to be used. The depth of the lesion was significantly associated with short-term complications of effusion and lameness. The depth and length of the lesion were not associated with the long-term outcome, but involvement of structures other than the lateral trochlear ridge (patella, medial trochlear ridge) was associated with a worse prognosis. CLINICAL SIGNIFICANCE: The prognosis for sport horses following stifle arthroscopy for lateral trochlear ridge is similar to that reported in other studies and lesions at other sites within the stifle joint.