Residual pivot shift after anterior cruciate ligament reconstruction using quadriceps tendon autograft (SS-16)

This retrospective study was performed to determine the clinical significance and the causes of residual pivot shift after ACL reconstruction using central quadriceps tendon autograft. Methods: 93 knees of 92 patients who underwent an arthroscopic ACL reconstruction using quadriceps tendon autograft were reviewed with a minimum two years of follow-up. Clinical results were evaluated by Lysholm score and Cybex dynamometer. Anterior laxity was assessed using KT-2000 arthrometer. Patients were classified into three groups by postoperative pivot shift and Lachman test; Group 1 (all negative), Group 2 (negative in Lachman and positive pivot shift), Group 3 (all positive). The radiographic analysis was performed by 1) the angle between tibial and femoral tunnel on plain A-P image, 2) the angle between tibial tunnel and anterior tibial cortex on lateral image, 3) the femoral and tibial tunnel location using Aglietti method. Postoperative knee MRIs were obtained and 1) the angle between joint line and the graft on sagittal and oblique coronal view, 2) the angle between Leo’s line and femoral tunnel on axial view were measured. Results: The number of patients in each group was 75, 8, and 10 respectively. Patients in group 1 showed greatest improvement in Lysholm score among groups, and patients in group 3 experienced greatest side-to-side difference by KT-2000 arthrometer. Radiological study showed that the angle between Leo’s line and femoral tunnel in MRI axial view was greatest in group 1 (P ≤ .05) and the angle between joint line and the graft on oblique coronal view was greatest in group 3 (P ≤ .05). Conclusions: This study suggests that the postoperative symptoms are related to Pivot shift rather than the results of Lachman test, and the residual Pivot shift is related to the vertical placement of the reconstructed ligament in coronal plane.