ANTIVITAMIN-K PREVENTS HETEROTOPIC OSSIFICATION AFTER HIP-ARTHROPLASTY IN DIFFUSE IDIOPATHIC SKELETAL HYPEROSTOSIS - A RETROSPECTIVE STUDY IN 67 PATIENTS

We investigated the risk of heterotopic ossification (HO) after total hip arthroplasty in 67 patients, 16 of whom had diffuse idiopathic ske letal hyperostosis (DISH). DISH was diagnosed on chest, dorsolumbar an d pelvic radiographs. HO was graded according to DeLee et al. (1976). After a 1.4 year follow-up, 21 patients had HO. The risk of HO was 5 t imes higher in DISH than in non-DISH patients, but lower in patients r eceiving antivitamin K than in those receiving other anticoagulant the rapy (relative risk 0.2). Our findings lead us to recommend that DISH should be diagnosed preoperatively for preventive therapy. They also s uggest a preventive effect of antivitamin K against heterotopic ossifi cation after hip arthroplasty.