[Heterotopic ossification as a complication of total hip replacement]

Heterotopic ossification is the most common complication after THR. The authors present the distribution of frequency of ectopic ossification after cementless THR using Mittelmeier and Parhofer-Mönch prosthesis and it's influence on THR outcome. 151 hip joints were evaluated with a follow-up period of more than 2 years. All procedures were performed by a lateral approach. The ectopic ossification was verified according to the Brooker classification. Clinical evaluation was performed according to the d'Aubigne-Postel method in Charnley's modification. The 3rd degree ectopic ossification was found in 14 hip joint and 4th degree ectopic ossification in 2 hip joints (together 10.6%). The positive correlation between the degree of ossification (3rd and 4th) and the decrease of range of motion of the hip joint along with an increase in pain after THR was found.