Augmentation of the Anterior Cruciate Ligament in Patients with Symptomatic Isolated Tear of Anteromedial or Posterolateral Bundle: Evaluation of Two-Year Clinical Results

We present the results of a prospective study of patients with symptomatic partial ACL tears comparing the pre-operative findings with the clinical results at two years after anterior cruciate ligament (ACL) augmentation. A total of 29 patients (7 women, 22 men; average age, 27.8 years) who were diagnosed with an isolated tear of the posterolateral (PL) bundle (18 patients) or the anteromedial (AM) bundle (11 patients) at 9 to 24 weeks after injury, and underwent ACL augmentation by isolated PL or AM bundle replacement, were evaluated. The characteristics assessed before surgery and at two years after it included the Lysholm and subjective IKDC scores and knee laxity measurement with a GNRB arthrometer (at 134 N and 250 N) and its assessment by the Lachman, anterior drawer and pivot shift tests. In addition, the presence of cyclop syndrome, graft failure and post-operative complications were evaluated. The patients with isolated reconstruction of the PL bundle showed post-operatively statistically significant improvement in the degree of rotational knee laxity (p < 0.05) and the ventral knee laxity assessed by the Lachman test (p < 0.05). Postoperative improvement in the anterior drawer test results was not statistically significant (p = 0.07). The median value of side-to-side difference in knee laxity measured with the GNRB arthrometer decreased at 134 N from 1.7 mm pre-operatively to 0.8 mm at two years post-operatively (p < 0.05) and, at 250 N, from 2.8 mm to 1.5 mm (p < 0.05). The median Lysholm score increased from 74 to 91 points at two post-operative years and the median IKDC score improved from 76 to 92 points (p < 0.05). Graft failure was reported in one patient (5.6%) and 14 subjects (77.8%) reported return to pre-injury sports activities. The patients undergoing isolated reconstruction of the AM bundle achieved, at two years after surgery, a statistically significant decrease in positivity of the Lachman and anterior drawer tests (p < 0.05), while the results of the pivot shift test did not improve significantly (p = 0.09). The decrease in median values of side-to-side difference in knee laxity measured with the GNRB arthrometer was from pre-operative 3.1 mm to 1.2 mm at 134 N (p < 0.05) and from 6.2 mm to 1.9 mm at 250N (p < 0.05). The median Lysholm and IKDC scores increased from 68 to 92 points and from 70 to 94 points, respectively (p < 0.05). Nine patients (81.9%) reported return to pre-injury participation in sports. Apart from early wound