The effect of unicompartmental knee arthroplasty on lower extremity axis, tibiofemoral subluxation, and lateral knee joint distance

Abstract

Purpose: The aim of this study was to investigate the corrective effect of Oxford phase 3 medial unicompartmental knee arthroplasty (UKA) on the lower extremity axis, tibiofemoral subluxation and lateral joint distance.
 Materials and Methods: The study included 105 knees that had undergone UKA. The Oxford Knee Score, EQ-5D-3LD and visual analog scale, and The Knee injury and Osteoarthritis Outcome Score were evaluated. Radiological evaluation was made of the lower extremity axis, tibiofemoral subluxation, and lateral knee joint distance.
 Results: The postoperative mean improvement in the mechanical axis was 1.4° and in the tibiofemoral subluxation distance, 1.59 mm compared to preoperative values. The difference between the preoperative and postoperative lateral joint distance values was on average 0.25 mm lateral inner joint distance, 0.08 mm in the lateral middle joint distance and 0.34 mm in the outer joint distance. There was no significant difference in clinical results between the groups.
 Conclusion: There were significant improvements in the postoperative period after cemented, cementless, and hybrid medial UKA in the measurements of lower extremity mechanical axis, tibiofemoral subluxation distance and lateral joint distances compared to the preoperative period.