Over a period of three years, a diagnosis of fragmented medial coronoid process of the ulna was confirmed by arthroscopy in 263 dogs, in 69 of which both elbow joints were affected, giving a total of 332 affected joints; 39 of the joints were also affected by osteochondrosis dissecans of the trochlea of the humerus. More than half of the dogs (51.7 per cent) were over one year old when first examined. In 259 (78 per cent) of the joints there were radiographic changes of secondary osteoarthrosis of different severity, but the other 73 (22 per cent) had no signs of osteophytosis except for a mild sclerosis. Among these 73 there were 14 joints in 13 dogs between 19 and 36 months old and 11 joints in 10 dogs over three years old. A further 12 joints in 11 dogs over three years old showed only mild arthrosis. In five of the 11 joints of the dogs over three years old which had no radiological signs of arthrosis, the fragment was already dislocated. Among the dogs over 18 months old with no arthrosis and the dogs over three years old with mild arthrosis, the most commonly affected breeds were the Bernese mountain dog, rottweiler and boxer.

SummaryIn a retrospective trial over eight years 518 joints from 421 dogs with fragmented medial coronoid process of the ulna (FCP) were included. Seventy-five joints had an additional osteochondrosis dissecans of the medial aspect of the humeral condyle. Forty-six point eight percent of the dogs (197/421) were younger than one year. Two hundred and forty-seven joints were treated by conventional arthrotomy and 271 joints were treated by arthroscopy. Two hundred and thirty-eight cases (103 treated by arthrotomy and 135 by arthroscopy) were re-evaluated clinically and radiographically and 191 cases (88 treated by arthrotomy and 103 by arthroscopy) by means of a questionnaire at an average of 23 and 21 months after the operations, respectively. Forty-two point four percent (81/191) of the cases treated by arthrotomy did not show any lameness, 29.3% (56/191) showed temporary lameness after rest or heavy exercise, and 28.3% (54/191) showed constant lameness. The signs of which had, however, been reduced by surgery in 14 of these cases. Sixty point one percent (143/238) of the cases treated by arthroscopy did not show any lameness, 29.4% (70/238) showed temporary lameness after rest or heavy exercise and 10.5% (25/238) showed constant lameness, out of which four cases had improved after surgery. In the cases treated by arthroscopy, the period of convalescence was shorter. Differences between these methods were not observed with respect to the development of subsequent arthrosis. The results of the study show that arthroscopy, with its minimal invasive character, gives better functional results than conventional arthrotomy. However, the development of secondary arthrosis cannot be avoided by either method.