Unicompartmental knee replacement combined with anterior cruciate ligament reconstruction provides comparable results to total knee replacement with no increased risk of complications.

Introduction: There is controversy about the management of unicompartmental knee osteoarthritis (OA) in young, active patients with anterior cruciate ligament (ACL) insufficiency. This study compares the subjective, radiological, and functional results of total knee replacement (TKR) vs. combined medial unicompartmental knee replacement (UKR) with ACL reconstruction.

Method: Twelve patients suffering from medial OA and ACL deficiency with varus knee deformity and/or tibial slope <10° and absence of patellofemoral-related problems were eligible for combined UKR and ACL reconstruction (Group A). Twenty-six patients matched for age, male/female ratio and body mass index who received TKR in the same time frame were included as a control group (Group B). Oxford Knee Score (OKS), WOMAC index of osteoarthritis, Knee Osteoarthritis Outcome Score (KOOS), and routine X-rays were used for assessment.

Results: Ten years after surgery, the mean overall KOOS score, OKS, WOMAC index increased from preoperatively, showing a statistically significant difference (p < 0.001). In terms of KOOS, OKS, or WOMAC scores at the most recent follow-up, there was no discernible difference between the groups (p = n.s.). Three years following surgery, one female patient in group A received revision TKR due to the lateral compartment's osteoarthritis developing and the patient's pain persisting. Concerning radiographic assessment, at the most recent follow-up (average 7.9 years in group A and 8.8 years in group B), there were no radiographic indications of implant loosening or proof of pathologic radiolucent lines.

Conclusions: UKR combined with ACL restoration offers clinical and radiographic outcomes comparable to TKR 10 years following surgery with no elevated risk of complications.