LAUSR

To investigate whether implant design affect (1)incidence of anterior knee pain, (2)patient reported outcomes and (3)reintervention rates in a resurfaced vs non-resurfaced Total Knee Arthroplasty (TKA). MEDline, pubmed and google scholar studies were evaluated using SIGN assessment tool and data analysis was conducted using Review Manager 5.2 on only randomised controlled trials. Search terms: arthroplasty, replacement, knee (Mesh), TKA, prosthesis, patella, patellar resurfacing, patellar retaining. 33 randomised controlled studies were identified. A total of 11 used the modern “patella-friendly” implants and 22 used the older “patella non-friendly” implants. There was no significant difference in anterior knee pain rates for either surgical option. When using patella-friendly implant, patella resurfacing results in a statistically higher clinical (P 0.007, MD -0.77) and functional (P < 0.0001, MD -1.87) KSS than the non-resurfaced counterparts, but scores were not clinically significant. When the patella was not resurfaced, there was a significant increased risk of reoperation with “non-patella friendly” implant (p=0.04, OR 1.42, CI 1.01, 2.00), whilst there was no significant difference between reoperation rates for the “patella friendly” implants (OR 1.17, CI 0.59,2.30). Patella implant design has been shown to significantly improve KSS scores but with no clinical significance. Risk of further procedures was significantly higher in non-resurfaced patella TKAs with “non-friendly” implants, likely due to increased rates of anterior knee pain in these older generation implants leading to secondary resurfacing. However, when utilising “patella-friendly” implants, resurfacing does not lower reintervention rates. This meta-analysis finds no clinical indication to resurface the patellar whilst performing a TKA.