Obesity does not adversely impact the outcome of unicompartmental knee arthroplasty for osteoarthritis: a meta-analysis of 80,798 subjects

• Published in: International Journal of Obesity Vol. 45; no. 4; pp. 715 - 724
• Main Authors: Agarwal, Nikhil, To, Kendrick, Zhang, Bridget, Khan, Wasim
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.04.2021; Nature Publishing Group
• Subjects: 692/308/174; 692/700/1538; Arthritis; Arthroplasty (knee); Arthroplasty, Replacement, Knee; Biomedical materials; Bone implants; Care and treatment; Complications and side effects; Contraindications; Epidemiology; Health Promotion and Disease Prevention; Humans; Internal Medicine; Joint replacement surgery; Joint surgery; Knee; Loosening; Medicine; Medicine & Public Health; Meta-analysis; Metabolic Diseases; Obesity; Obesity - complications; Osteoarthritis; Osteoarthritis, Knee - surgery; Patient outcomes; Patients; Prognosis; Public Health; Quality assessment; Quality control; Reoperation - statistics & numerical data; Review Article; Revisions; Statistical analysis; Subgroups; Surgery; Systematic review; Thromboembolism; Treatment Outcome; United Kingdom
• ISSN: 0307-0565; 1476-5497; 1476-5497
• DOI: 10.1038/s41366-020-00718-w

Background Patients with end-stage single compartment osteoarthritis benefit from the less invasive unicompartmental knee arthroplasty (UKA). With increasing financial restraints, some healthcare services have set specific BMI cut-offs when determining patient eligibility for knee arthroplasty due to perceived obesity-related complications. The aim of this systematic review is to determine the effect obesity has on outcomes following UKA, and thus elucidate whether obesity should be a contraindication for UKA. Methods A PRISMA systematic review was conducted using five databases (MEDLINE, EMBASE, Cochrane, PubMed and Web of Science) to identify all clinical studies that examined the effect of obesity on outcomes following UKA. Quantitative meta-analysis was carried out using RevMan 5.3 software. Quality assessment was carried out using the Critical Appraisal Skills Programme (CASP) checklist. Results Thirty studies, including a total of 80 798 patients were analysed. The mean follow- up duration was 5.42 years. Subgroup meta-analyses showed no statistically significant difference following UKA between patients cohorts with and without obesity in overall complication rates (95% CI, P  = 0.52), infection rates (95% CI, P  = 0.81), and revision surgeries (95% CI, P  = 0.06). When further analysing complications, no differences were identified in minor (95% CI, P  = 0.23) and major complications (95% CI, P  = 0.68), or venous thromboembolism rates (95% CI, P  = 0.06). When further analysing revision surgeries, no differences were identified for revisions specifically for infection (95% CI, P  = 0.71) or aseptic loosening (95% CI, P  = 0.75). Conclusions This meta-analysis shows that obesity does not result in poorer post-operative outcomes following UKA and should not be considered a contraindication for UKA. Future studies, including long-term follow-up RCTs and registry-level analyses, should examine factors associated with obesity and consider stratifying obesity to better delineate any potential differences in outcomes.