UMEM Educational Pearls


Take Home Point:

  • According to a recent article in the NEJM there does not seem to be any difference in the rate of symptomatic venous thromboembolism (VTE) in patients given low molecular weight heparin that underwent arthorscopy or had lower leg casting at 3 months.  
  • Overall, the rates of VTE were really low ( casting: 1.4% vs. 1.8%; arthroscopy: 0.7% vs. 0.4%), so there is probably not need for prophalaxis in these patients. 


Low-molecular-weight heparin doesn't seem to prevent symptomatic venous thromboembolism (VTE) in patients undergoing knee arthroscopy or lower leg casting, suggest two trials in the New England Journal of Medicine.

The study was conducted by Dutch researcheers and randomized 1500 patients who underwent lower leg casting or knee arthoscopy to receive no anticoagulation or low molecular weight heparin.  Patients were either treated for the entire duration of immobilzation or 8 days after their surgery (arthroscopy patients) 

The rates of VTE in patients at 3 months of follow up where arthroscopy: 0.7% vs. 0.4%; casting: 1.4% vs. 1.8%.  So overall very low rates of VTE, and no real difference between the groups.  

A large cohort might have shown some benefit, but since the incidence is so low there is probably no reason to prophlactically treat these patients and increase their risk of major bleeding events, which was also low in the study.

The article can be found at


van Adrichem RA, Nemeth B, Algra A, le Cessie S, Rosendaal FR, Schipper IB, et al. Thromboprophylaxis after Knee Arthroscopy and Lower-Leg Casting. N Engl J Med 2016.