[Personal experiences in surgical treatment of chronic instability of the anterior knee joint].

The results achieved with three different operative methods for the treatment of chronic anterior instabilities of the knee joint are presented. In 23 patients Trillat's modification of the O'Donoghue procedure was performed to reconstruct the medial collateral ligaments and the posterior capsule. Thirteen patients underwent reconstruction of the cruciate ligament with a free graft of the patellar ligament according to the Brückner method. In 37 patients the Brückner method was used for cruciate ligament replacement combined with lateral repair according to Ellison, and in some of these patients the posteromedial portion of the capsule was also reconstructed. Seventy-three patients (87.9% of all operated cases) were followed-up. The average observation period was 2.9 years and the mean age at the time of operation was 33.1 years. Major meniscal lesions were noted in 42 patients (57.5% of the cases). Twenty patients presented with combined instabilities or anteromedial grade II instabilities preoperatively. The majority of cases (53 patients) exhibited complex instabilities or anteromedial grade III instabilities preoperatively. At follow-up the Lachmann test was negative or trace-positive in 11 patients (48%) of group I, in 9 patients (69%) of group II, and in 34 patients (92%) of group III. Other stability tests, such as the pivot shift test and the drawer test, confirmed the superiority of group III. The overall results--considering both objective and subjective factors--showed good to excellent results in 12 patients of group I (52%), in 8 patients of group II (62%), and in 31 patients of group III (84%). We therefore conclude that combined and complex instabilities are indications for surgery.(ABSTRACT TRUNCATED AT 250 WORDS)