PREVENTION OF HETEROTOPIC OSSIFICATION USING SELECTIVE COX-2 INHIBITORS AFTER TOTAL HIP ARTHROPLASTY: A PROSPECTIVE RANDOMISED STUDY

Abstract

Purpose: Heterotopic ossification is a recognised complication after total hip arthroplasty. Prevalence can reach 53%, particularly if prophylaxis is not given, leading to postoperative pain and limiting the functional prognosis. Non-steroidal antiinflammatory drugs have proven efficacy but also present the risk of gastroduodenal toxicity making postoperative administration hasardous. Recently, selective COX-2 inhibitors have been shown to have a similar antiinflammatory activity with a clear reduction in gastrointestinal disorders. We hypothesised that selective COX-2 inhibitors could be as effective as classical NSAID for the prevention of heterotopic ossifications.

Material and methods: This clinical trial was conducted according to a prospective randomised protocol comparing a group of patients given prophylaxis with Celecoxib (Celebrex®) and another group of patients given ibuprofen (Brufen®). All patients scheduled for total elective prostheses were radomised in a prospective manner to one of the two groups, either Celecoxib 200mg b.i.d. or ibuprofen 400mg t.i.d. for ten immediate postoperative days. Radiological assessment was performed by two independent investigators blinded to the study (an orthopaedic surgeon and a radiologist) who scored calcifications according to the Brooker classification (type I to IV) at three months after surgery. Reproducibility of radiogram reading was tested and analysed with a kappa test K=0.74).

Results: Two hundred ten patients were randomised and 73 have had their three-month radiograms. The Cele-coxib group included 37 patients: 24 with Brooker stage 0, eleven with stage 1, two with stage 2. The ibuprofren group included 42 patients, 15 with Brooker 0, 16 with Brooker 1; nine with Brooker 2 and two with Brooker 3. The statistical analysis will be performed at the end of this study (June 2002).

Discussion: The preliminary results show that Celecoxib appears to have the same efficacy as ipubrofen for the prevention of heterotopic ossification after total hip arthroplasty. There was a clear trend in favour of Celecoxib.