Aspirin after hip or knee replacement: more symptomatic clots in pooled trials, but the signal leans on one study

The edition in brief

Today's orthopaedics edition ends on thromboprophylaxis after arthroplasty. An updated meta-analysis of 16 randomised trials (21,265 patients) found aspirin associated with more symptomatic DVT (RR 1.79), symptomatic VTE (RR 1.70) and pulmonary embolism (RR 1.89) than anticoagulants, with less minor bleeding and bruising and no significant difference in major bleeding. The symptomatic DVT and VTE signals lost significance when the large cluster-randomised CRISTAL trial was removed or only low-risk-of-bias trials were kept, so the result is fragile, but it argues for risk-stratifying rather than giving aspirin by default. A meta-analysis of 11 trials found no significant difference between topical and intravenous tranexamic acid in primary knee replacement for haemoglobin drop, blood loss or transfusion, with thin safety data. The 40-year follow-up of the first 75 hips treated by periacetabular osteotomy found 27% still free of hip replacement; preoperative osteoarthritis grade and a positive anterior impingement test predicted conversion. An external validation of Bone-RADS on 423 lytic long-bone lesions found 97% sensitivity for malignancy with moderate specificity, supporting it as a triage tool. The pearl covers VTE risk assessment before arthroplasty.