The influence of area level social deprivation on preoperative disease severity and postoperative outcomes following unicompartmental knee joint replacement

• We assessed the effect of social deprivation on outcomes in patients receiving a single UKR implant under the care of a single surgeon.
• Our study design controlled important confounding variables, which has not been done previously.
• More deprived patients can achieve similar improvements in OKS to less deprived patients following UKR.

BackgroundThis study investigated the effect of socioeconomic deprivation on preoperative disease and outcome following unicompartmental knee replacement (UKR).Methods307 Oxford UKRs implanted between 2008 and 2013 under the care of one surgeon using the same surgical technique were analysed. Deprivation was quantified using the Northern Ireland Multiple Deprivation Measure. Preoperative disease severity and postoperative outcome were measured using the Oxford Knee Score (OKS).ResultsThere was no difference in preoperative OKS between deprivation groups. Preoperative knee range of motion (ROM) was significantly reduced in more deprived patients with 10° less ROM than least deprived patients. Postoperatively there was no difference in OKS improvement between deprivation groups (p = 0.46), with improvements of 19.5 and 21.0 units in the most and least deprived groups respectively. There was no significant association between deprivation and OKS improvement on unadjusted or adjusted analysis. Preoperative OKS, Short Form 12 mental component score and length of stay were significant independent predictors of OKS improvement. A significantly lower proportion of the most deprived group (15%) reported being able to walk an unlimited distance compared to the least deprived group (41%) one year postoperatively.ConclusionMore deprived patients can achieve similar improvements in OKS to less deprived patients following UKR.Level of evidence2b — retrospective cohort study of prognosis.