Does a complete loss of articular cartilage of patella warrant a patellar resurfacing when combined with patellar denervation in primary total knee arthroplasty? Results of a randomized prospective trial

BACKGROUND: Complete cartilage loss and incomplete cartilage loss of the patella both have been reported to give good results with both resurfacing and nonresurfacing. We have tried to combine patellar denervation (PD) with the procedure and to compare the results of resurfacing or not resurfacing patella in posterior stabilized (PS) total knee arthroplasty (TKA). MATERIALS AND METHODS: A prospective single-center randomized prospective trial was done, including 68 patients undergoing unilateral TKA who were divided into patellar nonresurfacing (PNR) and patellar resurfacing (PR) groups. The patients underwent PS TKA. A blinded observer followed up the patients for 2 years, and visual analog scale at stairs (VAS-stairs), Knee Society Score (KSS), and range of motion were noted. RESULTS: The difference in VAS-stairs score from the baseline to the end of 1 month was significantly improved in the PR group, PNR = 4.4 ± 0.8 and PR = 5.5 ± 0.6, P = 0.0001. The difference in VAS-stairs score was significantly improved in the PR group again at 6 months, PNR = 5.9 ± 0.8 and PR = 7.1 ± 0.7, P = 0.0001. A comparison within the two groups at 1-month postop resulted in significantly better KSS 1 scores in the PR group (Chi-square value = 43.2, P < 0.001). When KSS 2 was compared between the two groups, we found no statistical significance in their preoperative scores and at postoperative time intervals of 1 month, 6 months, 1 year, and 2 years. CONCLUSIONS: Resurfacing patella with PD in an Outerbridge grade 4 patella yields better pain relief on stairs within the first 6 months. Also, resurfacing patella with PD in an Outerbridge grade 4 patella does not improve the functional outcomes at 2 years, and further long-term follow-up needs to be reported in the future.