Prevention of periarticular heterotopic ossification after endoprosthetic hip joint replacement by means of diclofenac.

This prospective study involves 644 patients who received ossification prophylaxis by means of the drug diclofenac after implantation (87.5%) or revision (12.5%) of a total hip endoprosthesis between August 1992 and June 1994. One hundred patients (15.5%) stopped the treatment because of side-effects of the drug, and medication was stopped when gastrointestinal troubles occurred. The follow-up examination after 6 months revealed ossification of HO degree 1 according to Brooker in 13.8% of cases, of degree 2 in 4.8%, and of degree 3 in 1.4% of cases. Severe HO of degree 4 was not observed at all, and 80% of the patients exhibited no ossification what ever. Thus, in comparison to our own studies and to the literature, diclofenac must be regarded as an extremely effective drug for the prevention of ossification.