[Patellar dislocation in athletes. Arthroscopic diagnosis and therapy].

Out of 270 arthroscopies performed in the Sports Clinic in Stuttgart-Bad Cannstatt in 1987 and 1988, 317 (11.5%) were done because of hemarthrosis of the knee after an acute trauma. Besides ruptures of the anterior cruciate ligament and synovial ruptures, in 53 cases (16.4%) acute patellar dislocation was found. These were only the first dislocations. Most, i.e., 44 (83%) occurred in sports, such as soccer (18) and skiing (9), which were the most frequent sports involved. Thirty-three (62.2%) were young men with an average age of 21.5 years. The clinical history, physical examination and plain X-rays failed in more than 50% to come up with a diagnosis. Arthroscopy showed the typical pattern of patellar dislocations with hemarthrosis, rupture and hematoma of the medial quadriceps retinaculum and a concomitant cartilage lesion, which was found in 39 cases (66%). During arthroscopy, operative treatment could also be performed, such as the extraction of splinter bone fragments and chondroplasties. Seven chondral and osteochondral fragments were refixated. Immobilization of the knee was guaranteed for 4 weeks by the application of a plaster splint. Only one recurrent dislocation was observed.