Anterior cruciate ligament reconstruction with bone-patellar tendon-bone graft : postoperative intervention and influential factors for patient-relevant long-term outcome

Abstract

The overall aim of the present thesis was to assess patient-relevant outcome after anterior cruciate ligament (ACL) reconstruction and to improve the knowledge of which factors that may predict longterm outcome after bone-patellar tendon-bone ACL reconstruction.

Study I: The purpose of this study was to evaluate the role of a brace after ACL reconstruction with bone-patellar tendon-bone graft on knee stability and knee function two years after surgery. Sixty-two patients, aged 16-49 years, were randomly allocated to a rehabilitation program with or without postoperative bracing for six weeks. Knee laxity (Stryker laxity tester), range of motion (goniometer), knee circumference for swelling (measuring tape), isokinetic thigh muscle torques (Kintrex dynamometer), a feeling of giving-way (Visual Analogue Scale, VAS), pain (VAS), a feeling of discomfort (VAS), knee function (Lysholm.Knee Scoring Scale) and activity level (Tegner Activity Scale) were assessed preoperatively, two and six weeks as well as three. six and 24 months after surgery. Additionally, the oneleg-hop test was assessed six and 24 months after surgery. For nonparametric measurements we used the Mann-Whitney U test and for parametric measurements an analysis of variance for repeated measures was used. Differences between groups were assessed by Student's t test for independent variables. At a two year follow-up we could not find any benefit of using a postoperative knee brace at any stage up to 24 months after surgery. There were no significant differences between groups in terms of knee joint stability indicating that a postoperative brace does not affect knee joint stability up to two years after surgery.

Study II: The purpose of this investigation was to study the long-term clinical outcome regarding patient reported knee function and knee related quality of life after bone-patellar tendon-bone ACL reconstruction on an average 11,5 years after surgery. We also wanted to investigate whether there were any correlations between the results of clinical tests that were performed two years after ACL reconstruction and patient reported knee function and knee related quality of life on an average 9,5 years later. For this study the entire patient cohort from Study I was followed-up. Of the original 62 patients, 56 patients were available at the two year follow-up. At the 11,5 year follow-up the original 62 patients were also invited to participate and we were able to follow-up 56 patients. Out of these 56 patients one patient was missing at both occasions. The results of the following tests at the two year follow-up were used to study possible predictors for patient reported long-term outcome of knee function and knee related quality of life as determined by two subscales (Function in sport and recreation and Knee related Quality of life) of Knee injury Osteoarthritis Outcome Score (KOOS) and three subscales (Bodily Pain, Role Physical and Physical Functioning) of SF-36. These tests were knee laxity (Stryker laxity tester), one-leg hop-test (measuring tape), isokinetic thigh muscle torques (Kintrex dynamometer), knee pain (VAS), time between injury and surgery, age at surgery, gender and knee function and activity level according to Lysholm Knee Scoring Scale and Tegner Activity Scale, respectively. Stepwise logistic regression and Spearman rank order correlation showed that there were no correlations between the results of KOOS or SF-36 and the addressed clinical tests or the results of the Lysholm Knee Scoring Scale and Tegner Activity Scale as evaluated two years after ACL reconstruction. We compared patients that had a side-to-side difference in anterior knee laxity of >3 mm with those of<3 mm and found no significant differences in terms of knee function in sports and recreation or knee related quality of life according to KOOS. We found no correlations between time of injury and surgery, age at surgery or gender, respectively and the results of KOOS or SF-36 at the long-term followup 11,5 years after ACL reconstruction. We could, however, conclude that the overall long-term outcome after ACL reconstruction with bone-patellar tendon-bone is satisfactory measured with KOOS, SF-36 and Lysholm Knee Scoring Scale.