Minimized Medial Soft Tissue Release with Bone-Recut Adjustment Improves Short-Term Outcomes: Compared with Medial Release in Posterior-Stabilized Total Knee Arthroplasty.

BACKGROUND Managing soft-tissue balance and selecting an appropriate alignment target are crucial factors in modern total knee arthroplasty (TKA). Medial soft-tissue release has been widely performed in posterior-stabilized (PS) TKA; however, recent approaches to medial structure management have been reconsidered. This retrospective study aimed to assess the effectiveness of minimizing medial structure invasion using personalized alignment (PA) with precise additional bone cutting in PS-TKA compared with conventional mechanically aligned (MA) PS-TKA. METHODS Overall, 188 patients who underwent PS-TKA were enrolled; propensity score matching on the basis of preoperative patient characteristics was used to ensure that the groups were similar. Additional medial soft-tissue release was performed if necessary in the MA group for inappropriate ligament balance. Adequate bone recutting, as an alternative to medial release, was performed in the PA group, permitting a maximum of 3° tibial varus alignment. RESULTS Additional medial soft-tissue release was performed in 33 knees (35.1%) in the MA group, whereas bone recutting was performed in 37 knees (39.4%) in the PA group. The PA group had a significantly more varus postoperative medial proximal tibial angle than the MA group (mean ± standard deviation, 89.1° ± 1.2° versus 90.3° ± 1.8°; p < 0.0001). The postoperative patient satisfaction score of the 2011 New Knee Society Score (KSS) in the PA group was significantly higher than that in the MA group (mean, 29.4 ± 6.7 versus 27.5 ± 7.3; p = 0.04). Moreover, PA with bone recutting resulted in a significantly greater postoperative extension angle (mean, -1.5° ± 3.7° versus -3.0° ± 3.5°; p = 0.02) and higher KSS patient satisfaction (30.1 ± 7.7 versus 26.7 ± 7.2; p = 0.04) compared with MA with medial release. CONCLUSIONS This novel surgical strategy achieved appropriate balance without excessive medial release and resulted in superior clinical outcomes in PS-TKA. LEVELS OF EVIDENCE Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.