Systematic lateral retinacular release does not reduce anterior knee pain after total knee arthroplasty with patellar resurfacing

Purpose The aim of this study was to assess the effect of systematic lateral retinacular release (LRR) on anterior knee pain (AKP), as well as its impact on the functional and radiological outcomes after total knee arthroplasty (TKA) with patellar resurfacing. Methods A prospective randomized study was designed. It included patients scheduled for a TKA procedure with patellar resurfacing, who were recruited and randomized into either the LRR group or the non-release group. 198 patients were included in the final analysis. The pressure pain threshold (PPT) assessed by pressure algometry (PA), the visual analogue scale (VAS), Feller's patellar score, the Knee Society Score (KSS), patellar height, and patellar tilt were recorded both preoperatively and at the 1-year follow-up. The Mann–Whitney U test was performed to determine comparisons between both groups as well as to determine differences’ intragroup. Results Relative to the clinical variables and scores, no difference was detected between the two groups at the 1-year follow-up ( p = n.s.). However, there was a slight difference in patellar tilt (0.1º vs. 1.4º, p = 0.044), with higher tilt values in the non-release group. There was no difference in terms of improvement in the clinical and radiological scores and variables recorded between the two groups ( p = n.s.). Conclusion LRR in primary TKA with patellar resurfacing does not show an improvement in AKP and functional outcomes over patellar resurfacing without release. Level of evidence I.