A meta-analysis published in the Journal of the American Medical Association has sought to estimate symptomatic venous thromboembolism (VTE) event rates prior to hospital discharge in patients undergoing total or partial hip arthroplasty (TPHA) or total or partial knee arthroplasty (TPKA).

The review included data from 47 randomised clinical trials and observational studies (involving 44,844 cases) that reported rates of postoperative symptomatic VTE in patients who received recommended VTE prophylaxis (with either a low-molecular-weight heparin or a subcutaneous factor Xa inhibitor or oral direct inhibitor of factors Xa or Iia) after undergoing TPHA or TPKA.

The following results were reported:
• The pooled rates of symptomatic postoperative VTE before hospital discharge were 1.09% (95% CI, 0.85%-1.33%) for patients undergoing TPKA and 0.53% (95% CI, 0.35%-0.70%) for those undergoing TPHA.
• The pooled rates of symptomatic DVT were 0.63% (95% CI, 0.47%-0.78%) for knee arthroplasty and 0.26% (95% CI, 0.14%-0.37%) for hip arthroplasty.
• The pooled rates for pulmonary embolism were 0.27% (95% CI, 0.16%-0.38%) for knee arthroplasty and 0.14% (95% CI, 0.07%-0.21%) for hip arthroplasty.

The researchers conclude that using current VTE prophylaxis, approximately 1 in 100 patients undergoing TPKA and approximately 1 in 200 patients undergoing TPHA develops symptomatic VTE prior to hospital discharge.

A related editorial discusses the meta-analysis.