Predictors and outcomes of lateral release in total knee arthroplasty: a cohort study of 1859 knees.

The use of lateral retinacular release (LR) to improve patellar tracking during total knee arthroplasty (TKR) remains contentious. This cohort study explored which pre-operative factors predicted LR, and analysed the effect of LR on short term complications and long term outcomes. One thousand eight hundred fifty-nine TKR patients were followed up for a mean of 5.49 years. One hundred fifty-four (8.3%) underwent LR. After regression analysis only, valgus deformity, year of surgery, maximal flexion and the operative surgeon predicted LR. LR patients stayed longer in hospital (10.8 vs 8.6 days) and had higher transfusion rates (20.3% vs 10.1%) than non-LR patients, but patellar fracture and infection rates were the same. Range of motion was poorer in the LR patients, but AKS Knee and functional scores were unaffected long term.