Background Ectopic ossifications (EO) following total hip replacement are possible and known post-operative complications, developing in about 60% of patients during the first 4–12 weeks after implantation. There is no treatment but surgery, therefore preventive measures are considered to be indispensible. Proven and sufficient measures to prevent EO are radiation treatment or treatment with non-steroidal anti-inflammatory drugs (NSAIDs). These measures are able to reduce EO to occur in about 10% of prophylactically treated patients.
Objectives The objective of this retrospective study was to evaluate our practice of treating patients postoperatively with the NSAID proglumetacin – a molecular combination of indomethacin with the gastroprotective substance proglumid – and to compare the success rate with that of competitive preventive treatments.
Methods During the years from 1995 to 1997 there were 560 patients in our orthopaedic department who underwent total hip replacement, in most of them because of osteoarthritis of the hip. Other reasons for surgery were femur head necrosis, rheumatoid arthritis, femoral neck fractures or loosening of an already existing hip endoprosthesis. Immediately after surgery, 2 weeks and again 2 months later, and, if possible, also 6 months later, control X-rays were performed. Signs of ossification were objectified using the Brooker classification.
Results 545 of these patients (573 women, 188 men; mean age: 66.8 ± 9.7 years; body weight: 75.6 ± 13.2 kg; body length: 167.3 ± 8.5 cm) were postoperatively treated for 3 weeks with proglumetacin. X-ray films of all patients after surgery showed no ossification, just as after 2 weeks the films of 506, after 2 months of 473, and after 6 months of 263 (of 329 re-examined) patients. Clinically not relevant ossifications (class I or II according to Brooker) were seen after 2 weeks in 37 patients (6.8%), after 2 months in 57 patients (10.5%) and after 6 months in 65 (11.9%) patients. Of all patients treated for at least one week no one (0.0%) showed a clinically relevant ossification (class III or IV). Two patients showing class III ossification were prophylactically treated only for 6 and 4 days, respectively. Concerning EO occurrence, in our patients there was no correlation with gender, kind of prosthesis or anaesthesia, duration of hip disease, or risk factors like already performed total hip replacement and diabetes mellitus, respectively.
Concerning safety only 43 patients (7.9%) complained of minor or increasing gastric adverse drug reactions, requiring additional gastroprotective drug therapy or even stop of treatment.
Conclusion In conclusion, the non-steroidal anti-inflammatory drug proglumetacin is very safe and at least as effective as other preventive measures and very safe. In our view, proglumetacin therefore represents a favourable and economic alternative treatment.
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