Abstract
AIMS AND OBJECTIVES: Recently, due to the development of new techniques, ACL repair has returned back into focus of experimental and clinical research. Newer studies highlight the fact that ACL repair can lead to satisfying functional results and healing rates. Aim of the present study was to compare the functional results after ACL repair in comparison to primary ACL reconstruction for acute isolated ACL tears. It was hypothesized, that functional results and knee joint stability after ACL repair are comparable to those after ACLR. MATERIALS AND METHODS: A prospective randomized study (Level of evidence 1) including a total of 85 patients with acute ACL tears was performed. Patients were randomized to undergo either ACL repair or primary ACL reconstruction with a semitendinosus autograft. The preinjury activity level and function were recorded. Follow-up examinations were performed at six weeks, six, twelve and 24 months postoperatively. At each follow up, the Tegner activity scale, the International Knee Documentation Committee (IKDC) subjective score and the Lysholm score were acquired. Furthermore, anterior tibial translation (ATT) was evaluated by Rolimeter testing. The rate of recurrent instability and other complications were recorded. RESULTS: 79 patients could be re-evaluated (follow-up rate 93%). No significant differences between ACL repair and ACLR were found for the Tegner, IKDC and Lysholm score at any time of the follow-up. ATT was increased in the ACL repair group (& ATT 1.9 vs. 0.9). This difference was statistically significant (p=0.0086). Seven patients (17%) of the ACL repair group presented with recurrent instability and underwent single-stage revision reconstruction with hamstring autografts. Another three patients showed increased laxity with insufficient healing after ACL repair but did not require revision. In the ACLR group, five patients (13%) sustained a re-tear after return to their previous activity level. However, in three cases, a two-staged revision was required. Recurrent instability was associated with young age and higher Tegner scores in both groups. CONCLUSION: Functional results after ACL repair for acute tears are comparable to those after ACLR. However, the rate of ACL insufficiency seems to be slightly increased after ACL repair. In the revision situation, single-stage revision was possible in all cases following primary repair, whereas after primary reconstruction, a two-staged revision had to be performed in three of five cases. The current study supports the use of ACL repair as an option to treat acute ACL tears.