Selective Patella Resurfacing in Contemporary Cruciate Retaining and Substituting Total Knee Arthroplasty: A Matched Cohort Analysis

• Published in: The Journal of arthroplasty 2023-03, Vol.38 (3), p.491-496
• Main Authors: Schmidt, Gregory J., Farooq, Hassan, Deckard, Evan R., Meneghini, R. Michael
• Format: Article
• Language: English
• Subjects: Arthroplasty, Replacement, Knee - methods; Cohort Studies; Humans; Knee Joint - surgery; Knee Prosthesis; matched cohorts; Osteoarthritis, Knee - surgery; Patella - surgery; patellar resurfacing; patient-reported outcomes; reoperation; total knee arthroplasty; Treatment Outcome; unresurfaced patella
• ISSN: 0883-5403; 1532-8406
• DOI: 10.1016/j.arth.2022.10.012

Leaving the patella unresurfaced in total knee arthroplasty (TKA) is increasing due to modern patella-friendly implants, awareness that complications are not uncommon with resurfacing, and knowledge that historical studies were scientifically confounded. This study examined the effect of selective patellar resurfacing on patient-reported outcome measures (PROMs) using modern implants and techniques in cohorts rigorously matched for demographics and osteoarthritis severity. A total of 166 TKAs performed without patellar resurfacing were case-control matched to 166 TKAs with patella resurfacing. Case-control matching was based on demographics, American Society of Anesthesiology Physical Status, comorbidities, and osteoarthritis severity. No significant differences were observed between cohorts for demographics (P ≥ .347), comorbidities (P ≥ .443), or radiographic osteoarthritis severity (P ≥ .078). Radiographic alignment and prospectively collected PROMs were evaluated preoperatively and at latest clinical follow-up. Preoperatively, patellar tilt was less for the unresurfaced patella group (3 versus 4°, P = .003); however, postoperative patellar tilt was not different (3 versus 3°, P = .225). At a mean of 2.1 years follow-up (range, 1 to 7), University of California Los Angeles Activity Level was significantly higher for the unresurfaced patella group (6.3 versus 5.5, P = .002), but the mean group difference did not reach a minimal clinically important difference. There were no other significant differences in PROMs or reoperation rates between cohorts (P ≥ .135). In contemporary cruciate retaining and substituting TKA designs, not resurfacing the patella in select patients may achieve comparable PROMs and re-operation rates; and potentially greater activity level compared to patella resurfacing at early follow-up. III.