Outcomes of manual kinematic alignment total knee arthroplasty in valgus knee deformity.

Abstract

The optimal alignment strategy in total knee arthroplasty remains debated, particularly in valgus deformities where lateral soft-tissue laxity and posterolateral tibial deficiency increase risk of instability. Mechanical alignment has traditionally been favored in this population, however interest in kinematic alignment (KA) has grown due to its emphasis on restoring native joint line orientation and ligament balance. Despite this, outcomes in valgus knees remain incompletely characterized. This study evaluates radiographic correction, clinical outcomes, and patient-reported measures following manual KA-TKA in patients with valgus deformity. A retrospective cohort review (Level IV evidence) was performed including patient who underwent primary manual KA-TKA between 2022 and 2025. Radiographic alignment, clinical outcomes, complications, range of motion, and patient-reported outcome measures (PROMIS Physical, PROMIS Mental, KOOS-JR) were assessed postoperatively. Among 178 primary KA-TKAs, 29 met valgus criteria and 25 were analyzed. Mean coronal valgus alignment improved from 11.2° ± 6.2 preoperatively to 4.1° ± 2.3 postoperatively, with all knees corrected to Ranawat class I. Complication rates were low (4%), consisting of one periprosthetic fracture. Mean one-year ROM was 126.0° ± 6.6°. PROM analysis was available for 10 patients (40%), demonstrating significant improvements in KOOS-JR scores at 6 months (p = 0.048) and 2 years (p = 0.039). PROMIS Physical scores improved at 3 months (p = 0.013) and 6 months (p < 0.001). PROMIS Mental scores did not significantly change. Manual kinematic alignment produced acceptable early radiographic correction, favorable functional outcomes, and low short term complication rate in a selected cohort of valgus knees. These findings support the feasibility of KA in this population, however, larger comparative studies with long term follow up are needed.