Does Patellar Resurfacing Improve Outcomes in Valgus Osteoarthritis with Compromised Patellofemoral Joint Status? A Retrospective Consecutive Comparative Study.

Background/Objectives: The benefit of patellar resurfacing (PR) in total knee arthroplasty (TKA) remains controversial. No previous study has examined the impact of PR in valgus osteoarthritis (OA) with compromised patellofemoral joint (PFJ) status. Methods: We retrospectively reviewed 2250 primary TKAs performed between 2011 and 2025. Among 152 valgus OA cases, 87 had compromised PFJ status, defined as Outerbridge grade 3-4 chondral damage or patellar tilt >10° on Merchant-view radiographs. Two surgeons with identical protocols operated during overlapping periods; one typically performed PR (n = 47) and the other did not (n = 40). Primary outcomes included the American Knee Society (AKS) score and Kujala Anterior Knee Pain Scale. Secondary outcomes included radiologic measures (HKA angle, patellar tilt, and lateral patella shift) and patellar-related complications (crepitus, fracture, subluxation, and maltracking). Results: At a mean follow-up of 7.1 years in the non-PR group and 6.5 years in the PR group, no significant differences were observed between groups in KSS function scores (non-PR 92.4 ± 3.5 vs. PR 93.0 ± 4.6, p = 0.54) or Kujala scores (non-PR 76.9 ± 3.5 vs. PR 77.7 ± 4.2, p = 0.33). Both patellar tilt and lateral patella shift showed slight postoperative reductions, but no significant difference was observed between groups (patellar tilt: non-PR 5.4° ± 0.8° vs. PR 5.7° ± 0.6°, p = 0.11; lateral patella shift: non-PR 2.4 ± 0.6 mm vs. PR 2.3 ± 0.7 mm, p = 0.75). Patellar-related complications were infrequent and showed no significant differences. Conclusions: Overall, PR did not demonstrate superior outcomes compared with non-PR in valgus OA patients with compromised PFJ status at mid-term follow-up.