Is Patella Resurfacing Associated With Postoperative Extensor Mechanism Disruption After Total Knee Arthroplasty? A Systematic Review and Meta-Analysis.

Background: Patella resurfacing in total knee arthroplasty (TKA) involves surgical manipulation of the extensor mechanism, which can weaken or devascularize the patellar bone, quadriceps, and patellar tendon. Patella resurfacing may, in theory, increase the risk of postoperative extensor mechanism disruption (EMD).

Methods: We systematically searched the Cochrane, Embase, and PubMed databases to identify randomized controlled trials that reported the overall incidence of complications and surgery for EMD for resurfaced and unresurfaced patellae in patients who underwent primary TKA with a 2-year follow-up. There were nine studies included in the meta-analysis, representing 1,569 patients, 773 of whom (49%) underwent patella resurfacing. Study selection was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A common-effects model was used to calculate the pooled effects as log odds ratios (ORs) and 95% confidence intervals (CIs). P < 0.05 was considered significant.

Results: The unadjusted incidence of postoperative patellar fracture was equivalent for patients who did not have patella resurfacing (0.26%) and for those who had resurfacing (0.38%) (P = 0.51). Postoperative patellar tendon tears were not reported in any patients. Quadriceps tendon tears were also uncommon, with one instance occurring in the unresurfaced group (0.13%) and one instance in the resurfaced group (0.13%) (P = 0.74). Meta-analysis revealed no significant association between patella resurfacing and sustaining any EMD-related complication (OR 0.22, 95% CI: -1.24 to 0.80) or requiring surgery for EMD (OR 0.22, 95% CI: -0.92 to 1.36).

Conclusions: In this large patient sample, the 2-year incidence of EMD-related complications after TKA was low. However, a meta-analysis of the pooled data suggests that patella resurfacing in TKA is not associated with the incidence of postoperative EMD-related complications or surgery for EMD.

Level Of Evidence: III.