Prevention of heterotopic ossification in cases of hypertrophic osteoarthritis submitted to total hip arthroplasty. Etidronate or Indomethacin?

G.I. Vasileiadis (1), V.I. Sakellariou (1), A. Kelekis (2), A. Galanos (3), P.N. Soucacos (1), P.J. Papagelopoulos (1), G.C. Babis (1)

(1) 1st Orthopaedic Department, University of Athens, ATTIKON University General Hospital, Athens, Greece;
(2) Department of Radiology, University of Athens, ATTIKON University General Hospital, Athens, Greece;
(3) Laboratory for the Research of Musculoskeletal System, University of Athens, Greece

Abstract
We present a study comparing etidronate or indomethacin for the prevention of heterotopic ossification after total hip arthroplasty in patients with hypertrophic osteoarthritis. 52 patients were divided in two groups. Group A (26 patients) received etidronate (20 mg/kg/day for 12 weeks) and Group B (26 patients) indomethacin 75mg/day for 2 weeks. Mean follow up was 36 months (range, 18 to 50 months). The incidence of side effects was 15.4% in group A and 30.8% in group B (p=0.324). At 6 months there was no statistically significant difference in terms of clinical (p=0.532) and radiographic evaluation between the two groups (p=0.303). However, the cost of etidronate which may be as much as six times more expensive than that of indomethacin could not justify its routine prophylactic use.

Keywords: Heterotopic, Ossification, Etidronate, Indomethacin, Arthroplasty, Hip, Hypertrophic, Osteoarthritis