Factors Associated with the Development of Heterotopic Ossification in Two Different Types of Hip Prosthesis

Abstract

The Authors evaluated the incidence and the dimensions of heterotopic ossifications (HO) in two groups of patients in which two different types of prosthesis were implanted. The first group of 31 patients had received an alumina-alumina Rosenthal-SAMO total hip replacement, while the second group (79 patients) had a metal-polyethylene Charnley low friction arthroplasty. While the total incidence of HO was similar, the HO were significantly smaller in the first group (all grade I according to Brooker)(3). The patients’ clinical files were retrospectively examined, but it was not possible to find any significant difference for the following parameters: age, sex, side, previous homolateral surgery, diagnosis, operating team, operating time, type of anaesthesia, and blood loss during surgery. The only difference was in the number of suction drains positioned: two in the first group and one in the second. Even if it is impossible to draw a definite conclusion, we postulate that the decrease in volume and duration of the periprosthetic haematoma, and the smaller amount of debris caused by the alumina-alumina coupling, could be of protective value.