[A problem with surgical treatment of ectopic ossification after total hip replacement]

The author presents the issue and the results of surgical treatment of ectopic (heterotopic) ossification following total hip replacement. Four patients (3 female patients aged 44, 52 and 59 years and one male patient aged 58 years) in whom ectopic ossification occurred as a late complication and who had major ROM limitation were treated surgically. The three female patients were from the risk group and the evolution of ossification had a typical course, in the male patient ossification occurred 6 years after hip replacement and was preceded by trauma and a haematoma proximal to the hip prostheses. ROM limitation was more dependent on the localisation of the ossification rather than it's extent. In all cases a major increase in ROM was noted, with intra-operatively and post-op. A good functional result was found in 3 cases 12 months after surgery. In one case, where the extent of the ossification was least, ROM decreased considerably when compared to the intra-operative result. Radiological follow-up at 3, 6 and 12 months after surgical treatment didn't reveal any signs of renewal of the ossification process. Routine prophylactics of ectopic ossification consisted of administration of NSAID (Metindol 1 g/24 h) and a low-calcium diet. The author believes that cases of ectopic ossification leading to hip contractures and major ROM limitations are best treated by surgical resection.