Clinical effect of rotating alignment technique of medial pivot type tibial prosthesis in total knee arthroplasty

ObjectiveThis study aimed to evaluate the clinical efficacy of different rotational alignment techniques for the tibial component in total knee arthroplasty (TKA) using a Medial Pivot (MP) knee system, providing improved strategies for tibial prosthesis positioning.MethodsA retrospective analysis included 115 patients with end-stage osteoarthritis who underwent MP-TKA at our hospital from January 2022 to June 2025. Patients were grouped based on tibial alignment reference points: the medial one-third of the tibial tubercle (medial 1/3 group) and the midpoint of the tibial tubercle (midpoint group). Intraoperative variables-operation time, incision length, blood loss-were recorded. Postoperative knee function was assessed using the Hospital for Special Surgery (HSS) score, Visual Analogue Scale (VAS), and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Tibial posterior slope angles evaluated prosthesis positioning accuracy, and postoperative complications (infection, anterior knee pain, deep vein thrombosis) were documented.ResultsThe average follow-up was 15.87 ± 3.87 months. Baseline and intraoperative data showed no significant differences between groups (p > 0.05). The medial 1/3 group reported one incision infection and four cases of anterior knee pain; the midpoint group had no infections and two cases of anterior knee pain, all resolved with treatment. At 1 and 6 months postoperatively, the midpoint group had significantly higher HSS scores and lower VAS and WOMAC scores compared to the medial 1/3 group (p < 0.05). Tibial posterior slope <1° was more frequent in the midpoint group (75.86% vs 59.65%), indicating more accurate alignment.ConclusionUsing the tibial tubercle midpoint for tibial component alignment in MP-TKA results in better prosthesis fit, improved knee function, and reduced anterior knee pain compared to the medial one-third reference, offering a preferable clinical approach.