[Conversion of Arthrodesis and Ankylosis of the Hip Joint to THR.]

Conversion of arthrodesis or ankylosis of the hip joint toTHR is a very difficult operation from the technical viewpoint. However, with a deliberate indication it may conduce to a significant improvement of the quality of life of the patient. Indications for such operation are the following: arthrodesis in malposition, increasing lowback pain, difficulties with personal hygiene and problems in the sexual life, instability of knee or its deformity given by the incorrect position of the hip joint. Contraindication is florid osteomyelitis, serious damage of muscles in the region of the hip joint, serious neurological affection and myopathy. We do not consider a preceding specific or non-specific arthritis of the hip joint as a contradiction on condition that a proper time interval has been observed. At the Orthopaedic Clinic of 1st Medical Faculty, Charles University we performed in the period 1985-1997 a conversion of arthrodesis or ankylosis of the hip joint to THR in 12 patients in the above mentioned indications. Of all these operations we twice encountered a relative failure. In the first case there developed THR infection, however the primary diagnosis was not an infectious arthritis of the joint. In the second case there occurred aseptic loosening of the cup. Even though both cases had to be consequently treated by Girdlestone arthroplasty all patients appreciate the operation as a considerable improvement of the quality of their life. In all 12 patients the range of active motion of the hip joint has been restored, in 10 patients the length of the limb has been corrected. Key words: conversion, arthrodesis of the hip joint, THR.