Effect of different degrees of primary varus knee on short-term effectiveness of anterior cruciate ligament reconstruction

Abstract

To investigate whether different degrees of primary varus knee affect joint function and stability in patients undergoing anterior cruciate ligament (ACL) reconstruction. A clinical data of 160 patients with primary varus knee, who were admitted between January 2020 and December 2021 and met the selection criteria, was retrospectively analyzed. All patients underwent primary ACL reconstruction using autologous single-bundle hamstring tendon. Patients were divided into three groups based on the hip-knee-ankle angle (HKA): group A (64 patients with HKA 0°-3°), group B (55 patients with HKA 3°-6°), and group C (41 patients with HKA 6°-9°). Except for the significant difference in HKA among the three groups ( P<0.05), baseline data such as age, gender, affected side, body mass index, interval between injury and operation, Kellgren-Lawrence grading, posterior tibial slope, proportion of combined meniscal injuries, Tegner score, Lysholm score, and International Knee Documentation Committee (IKDC) objective score, anterior drawer test, Lachman test, pivot shift test, and the results of KT1000 (side-to-side difference, SSD) showed no significant difference ( P>0.05). At last follow-up, joint stability was assessed through the anterior drawer test, Lachman test, pivot shift test, and SSD; joint function was evaluated using the Tegner score, Lysholm score, and IKDC objective score. All incisions in the three groups healed by first intention after operation. All patients were followed up 24-31 months, with an average of 26 months; there was no significant difference in the follow-up time among the three groups ( Z=0.675, P=0.714). At last follow-up, the knee stability and functional assessment indicators in each group significantly improved when compared to preoperative ones ( P<0.05); there was no significant difference among the three groups ( P>0.05) in terms of the anterior drawer test, Lachman test, pivot shift test, IKDC objective scores, and the changes of the Lysholm scores and Tegner scores. The Kellgren-Lawrence grading and HKA at last follow-up were consistent with preoperative results in the three groups. Varying degrees of primary varus knee do not affect early knee joint stability and functional recovery after ACL reconstruction, and there is no significant difference in effectiveness between different degrees of varus knee.