Radiofrequency electrothermal shrinkage of the anterior cruciate ligament.

The efficacy of electrothermal collagen shrinkage in the treatment of patients with anterior cruciate ligament laxity was evaluated. Eighteen patients who had continuity of the anterior cruciate ligament but had symptomatic laxity were treated with arthroscopic electrothermal shrinkage of the anterior cruciate ligament using a monopolar radiofrequency probe. The mean length of follow-up in patients whose stability was maintained was 20.5 months. Seven of the patients had undergone previous reconstruction, four with patellar tendon graft and three with quadrupled hamstring tendon graft. Laxity was chronic in nine patients and acute in nine. The KT-1000 arthrometer results at 1 month postoperatively revealed decreased anterior excursion, with an average side-to-side difference of 1.9 mm. However, 11 patients had a failed result at an average 4.0 months. Of the seven patients with successful results, six had native ligaments and had been treated for acute laxity and one had a patellar tendon graft and had been treated for chronic laxity. Even with the short-term follow-up in our study, it is evident that thermal shrinkage using radiofrequency technology has limited application for patients with anterior cruciate ligament laxity. Although it may be useful in treating patients with an acutely injured native anterior cruciate ligament, further study is needed to see if the ligament stretches out over time or is at increased risk of reinjury.