Evaluation of Anterior Cruciate Ligament Reconstruction Using Anterior Tibial Muscle Tendon Allograft

PURPOSE OF THE STUDY Injury to the anterior cruciate ligament (ACL) frequently results in the development of knee instability. This is managed by ACL reconstruction using autogenous or allogeneic grafts. This study presents a comprehensive evaluation of the patients with ACL reconstruction using a tendon allograft harvested from the anterior tibial muscle (ATM). MATERIAL AND METHODS The group under study comprised 53 patients, 33 men and 20 women, with unilateral ACL reconstruction while the other knee was intact. The average age was 32.4 years (17 to 51) and the average follow-up was 33,4 months (21 to 53). Clinical evaluation included the Tegner and Lysholm scores and questionnaire-based satisfaction rating. Functional assessment included measurements of the range of motion and thigh circumference. Knee stability was determined using the pivot shift test, Lachman test and one-leg hop test. ACL laxity was measured on a GNRB (R) arthrometer. Placement of the tibial and the femoral tunnel on radiographs was assessed by the method of Harner. RESULTS All patients reported their willingness to undergo the surgery again. The average pre-operative Tegner score improved from 7.17 (4-10) to 6.45 (2-10; p = 0.0001). The average post-operative Lysholm score was 87 points (47-100). At final follow-up, the full range of motion was recorded in 39 patients (74%), while the remaining patients exhibited only insignificant restriction of knee motion in comparison with the pre-operative status. The results of the Lachman test were negative in 38 patients (71.7%) while the pivot shift test was negative in 52 patients (98.1%). In the one-leg hop test, 44 patients (83%) were able to jump on the treated leg for a distance longer than 90% of the distance done on the healthy leg. The GNRB test at a force of 134N showed an anterior shift of the proximal tibia by 2.2 mm (0.1-9.3) on the average. The tibial tunnel was placed in zone B in 48 patients (90.6%) and the femoral tunnel was most often located to zone D (n = 47; 88.7%). DISCUSSION The choice of tissue for ACL reconstruction is still being discussed. In some centres an ATM tendon allograft is used only in revision surgery while, in other centres, it is also employed in primary procedures. Recent studies on ACL surgery suggest that outcomes are relatively independent of the material used for reconstruction. In view of evidence-based medicine, more well-conducted multicentre clinical trials are needed to optimise indications for allograft ACL reconstruction. CONCLUSIONS The ACL reconstruction using an ATM tendon allograft showed good clinical outcome at a minimum follow-up of 21 months. The method can be recommended not only for revision ACL reconstruction but also in primary reconstructions particularly in elderly patients. The present-day technology of producing allografts maintains tissue biomechanical characteristics and reduces risks for transmission of infection to a minimum.