[Critical assessment of indications for arthroscopic lateral release and medial tightening of the knee joint].

UNLABELLED: Based on the results of a retrospective study of 50 patients with mild lateral tracking and lateral compression of the patella (32 patients) and recurrent patellofemoral dislocation (18 patients), we present the technique, the results, the complications and the indications for the endoscopic lateral retinacular release and medial drawing tight of the capsule. The average age of the patients was 28.8 years (range: 10-53). At time of follow-up (m = 51 months) the patients were examined clinically as well as radiologically. The results were scored according to a score by Crosby and Insall. 73% of the patients with mild lateral tracking and lateral compression (lateral release) were satisfied with the operative results (visual analogue scale), as well as 66.6% of the patients with recurrent patellofemoral dislocation (lateral release and medial drawing tight of the capsule). Only 40% of the patients with patellofemoral arthritis (lateral release) reported about an improvement of this procedure. The score showed significantly good results but didn't raise the differences in between the groups of different indications. 28% of the patients showed an abnormal lateral tracking of the patella in active motion, the passive patella-glide-test (Hughston) raised a patella-hypermobility to the lateral side in 36% of the cases and to the medial side in 76%. X-rays of both knees showed an increased lateral patellofemoral angle of 10.8 degrees and an increased sulcus angle of 144 degrees. There was no progression in osteoarthritis in the operated side of the patellofemoral joint found. Complications revealed in a high number of hemarthrosis right after the operation, in 2 cases an open revision was necessary.

CLINICAL RELEVANCE: According to our results patients with patella compression syndrome without patellofemoral arthritis and patients with recurrent luxation or subluxation of the patella are good candidates for endoscopic lateral release and eventually medial drawing tight of the capsule. In a young population the endoscopic lateral release is a relatively simple surgical procedure making an open technique in failed cases possible.