Stifle lameness in the horse: a survey of 86 referred cases.

The clinical and radiological characteristics of stifle lameness in 86 horses are described. The majority of these cases had been lame for some weeks before referral. The most frequent diagnoses made were osteochondrosis dissecans (13 per cent) and subchondral bone cyst (38 per cent). Both of these conditions were seen principally in Thoroughbreds at or before the onset of training. The other bone lesions encountered were osteoarthritis (3 per cent), fractures (4 per cent) and "epiphysitis" (1 per cent). The commonest soft tissue condition was an atypical or partial upward fixation of the patella (15 per cent), ligamentous/meniscal damage comprised 12 per cent of the cases and the remaining 13 per cent were attributed to non-specific strain of the stifle joint. Treatment in most of these chronic stifle injuries consisted of a period of rest followed by a gradual return to exercise; in some cases this was combined with a short course of a non-steroidal anti-inflammatory drug. The prognosis in most cases of osteochondrosis dissecans was grave to hopeless, while the majority of the horses with a subchondral bone cyst improved clinically after an extended period of rest (ie, 6 months). Ligamentous/meniscal damage usually responded satisfactorily to rest, provided there was no gross tearing or rupture of the structures involved. The outcome in cases of chronic osteoarthritis was always poor and these cases did not respond satisfactorily to analgesic and anti-inflammatory medication.