Obesity does not influence the outcome of unicompartmental knee arthroplasty for osteoarthritis

  • Agarwal N & al.
  • Int J Obes (Lond)
  • 19 Nov 2020

  • curated by Sarfaroj Khan
  • UK Clinical Digest
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  • This meta-analysis suggests that obesity does not result in poorer post-operative outcomes following unicompartmental knee arthroplasty (UKA) for osteoarthritis and should not be considered a contradiction for UKA.

Why this matters

  • The use of UKA for single compartment end-stage OA has significantly increased and studies have suggested that this procedure has good functional outcomes and offers several advantages over total knee arthroplasty. However, its use in patients with obesity has been surrounded by controversy.
  • Findings warrant further studies to examine factors associated with obesity and consider stratifying obesity to better delineate any potential differences in outcomes.

Study design

  • 30 studies (mean follow-up duration, 5.42 years) including 80,798 patients met eligibility criteria after a search on MEDLINE, EMBASE, Cochrane, PubMed and Web of Science.
  • Funding: None disclosed.

Key results

  • Subgroup meta-analyses revealed no statistically significant difference following UKA between patients with and without obesity in overall:
    • complication rates (OR, 1.36; 95% CI, 0.54-3.43; P=.52; I2, 97%);
    • infection rates (OR, 1.09; 95% CI, 0.54-2.17; P=.81; I2, 80%); and
    • revision surgeries (OR, 1.60; 95% CI, 0.98-2.62; P=.06; I2, 86%).
  • When further analysing complications, no significant differences were seen in:
    • minor complications (OR, 1.82; 95% CI, 0.69-4.89; P=.23; I2, 91%);
    • major complications (OR, 1.36; 95% CI, 0.32-5.68; P=.68; I2, 97%); and
    • venous thromboembolism rates (OR, 0.77; 95% CI, 0.58-1.01; P=.06; I2, 72%).
  • No significant differences were seen for revision surgeries specifically for:
    • infection (OR, 0.89; 95% CI, 0.49-1.63; P=.71); and
    • aseptic loosening (OR, 1.05; 95% CI, 0.79-1.39; P=.75).


  • Heterogeneity among included studies.