THE SEMITENDINOSUS TENDON FOR ANTERIOR CRUCIATE LIGAMENT REPLACEMENT

This article describes the history, advantages, biomechanical properti es, operative technique, and results of replacement of the anterior cr uciate ligament using the semitendinosus tendon. After arthroscopic AC L replacement using the doubled semitendinosus tendon in combination w ith an extraarticular lateral repair in 65 consecutive patients (20 ac ute, 45 chronic instabilities) we found after 2 years in 51 patients ( 78 %) an excellent or good result with less than 3 mm difference in th e Lachman test measured with the KT-1000 arthrometer (MMD). After 6 ye ars 40 out of the 45 patients with chronic instabilities could be exam ined again. Only 28 patients (70 %) showed a difference in anterior tr anslation of less than 3 mm. A positive pivot shift sign could be seen in 11 % of the patients after 2 years and in 20 % after 6 years. The Tegner score increased from 6.0 after 2 years to 6.2 after 6 years, th e Lysholm score decreased from 93 to 91 in the same interval. 89 % of the patients had a free range of knee motion after 2 years and 92.5 % after 6 years. There were 10 % normal, 50 % nearly normal? 25 % abnorm al, and 15 % severely abnormal knees in the IKDC evaluation after 6 ye ars. In the last 4 years we are using the quadrupled semitendinosus te ndon in an arthroscopic single incision technique for ACL replacement with femoral Endobutton fixation, because the doubled semitendinosus t endon seems to elongate over time. After 23 months on average (12-36 m onths) the preoperative anterior translation of 7.5 mm could be decrea sed to 1.9 mm in 35 patients.