Circumpatellar Denervation With Patelloplasty in Primary Total Knee Arthroplasty Without Resurfacing: Five-year Outcomes by International Cartilage Repair Society Patellar Cartilage Grade

Background: Patellar management in primary total knee arthroplasty (TKA) remains controversial. When the patella is not resurfaced, circumpatellar denervation with patelloplasty (CP + PP) is widely used, but it is unclear whether outcomes differ by International Cartilage Repair Society (ICRS) patellar cartilage grade. Methods: We conducted a cohort study of TKAs performed with a standardized non-resurfacing protocol incorporating CP + PP. Intraoperative patellar cartilage was graded ICRS 2, 3, or 4. Four patient-reported outcomes (PROs)-Oxford Knee Score (OKS), visual analog scale (VAS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and Kujala Anterior Knee Pain Scale (AKPS)-were assessed up to 60 months. Longitudinal change was modeled with generalized estimating equations, and adjusted estimated marginal means (EMMs) at 60 months were compared across ICRS grades. Minimal clinically important difference (MCID) thresholds were used to calculate the proportion of knees that improved. Results: We analyzed 180 knees (26 ICRS 2, 112 ICRS 3, 42 ICRS 4). All PROs improved markedly, with high 60-month OKS and AKPS scores and near-floor VAS and WOMAC values. Every knee exceeded the MCID for all 4 PROs (100%). Adjusted 60-month EMMs were similar across ICRS grades for OKS, VAS, and WOMAC. AKPS showed a small adjusted advantage for ICRS 4 vs 2 (EMM difference +4.35). Complications were uncommon and did not differ significantly by grade. Conclusions: In non-resurfacing primary TKA, a standardized CP + PP protocol produced durable 5-year improvement, with universal attainment of MCID and only minor differences across ICRS grades. CP + PP appears to be a reproducible non-resurfacing option.