Medial pivot total knee arthroplasty: the role of baseline pain in clinical and functional improvement at one year

Fallaque-Ruiz Y.X.; Centeno-Leguía D.; Mendoza-Vera V.N.; Avendaño-Uchuya O.; Fallaque-Ruiz C.E.; Cajo-Salvador J. · Horizonte Medico (2026) · DOI: 10.24265/horizmed.2026.v26n2.03

Resumen

Objective: To evaluate clinical and functional outcomes following primary medial pivot total knee arthroplasty (MP-TKA) and to analyze factors associated with pain improvement at one year. Materials and methods: A prospective single-center cohort study including patients with Kellgren–Lawrence grade 3–4 knee osteoarthritis who underwent primary MP-TKA. Outcomes were assessed preoperatively and at 3, 6, and 12 months using the Knee Injury and Osteoarthritis Outcome Score (KOOS) and the Short Form-36 (SF-36). The primary outcome was change in KOOS Pain (ΔKOOS Pain) at one year. A parsimonious multivariable linear regression model was used. Results: Twenty-five patients were included (mean age: 67.8 ± 7.9 years; 64% women). KOOS Pain improved from 44.4 ± 8.9 to 79.0 ± 13.7 at one year. ΔKOOS Pain was 34.6 points (95% CI: 26.8–42.3; p < 0.001), exceeding the minimum clinically important difference. Improvements were observed across all KOOS and SF-36 domains. Preoperative KOOS Pain was the only factor independently associated with pain improvement (β = −1.46; 95% CI: −2.15 to −0.77; p < 0.001). Conclusions: MP-TKA was associated with significant clinical and functional improvement at one year. Baseline pain was a key determinant of postoperative improvement, with implications for patient selection and expectation management.

Instituciones: Universidad Ricardo Palma