SUMMARY

The authors evaluate a group of 192 patients opera-ted in 1983 at the Orthopaedic Clinic of the Institute for Postgraduate Medical Training to whom 196 cemented total endoprostheses of the hip joint type Poldi were implanted. Of these 53.1 % patients were operated on account of primary arthritis, 29.1 % on account of postdysplastic arthritis of the hip joint. In four patients conversion of an osseous ankylosis to an endoprost-hesis was performed. In 59.7 % a medium Poldi socket was ušed, in 36.5 % a small Poldi socket and in 13.8 % a large Poldi socket. For fixation in all patients Palacos cement with first generation technique was ušed. In seven patients augmentation of a dysplastic acetabu-lum by an autogenous graft, as described by Harris, was made. The number of peroperative complications and technical errors does not exceed data in the lite-ratuře. 15.8 % hip joints were re-operated - 0.5 % on account of a relapsing dislocation, 0.5 % because of early failure of the cement-bone bond due to bad cementing technique of the acetabular component, 1 % on account of latě septic release, 0.5 % because of isolated aseptic release of the shank, 2.6 % because of aseptic release of both components and 10.7 % on account of aseptic release of the acetabular compo-nent, on average 8.3 years after surgery. Aseptic rele-ase of the socket correlates significantly with the size of the socket ušed and with the originál diagnosis.

The mean wear of the small socket is 0.22 mm per year, of the medium socket 0.28 mm per year and of the large socket 0.12 mm per year. Sockets of small size become released four times as frequently as medium and large ones and release is twice as frequ-ent after surgery of secondary postdysplastic arhritis than after implantation on account of deforming arth-ritis of the hip joint.

When evaluating the group of 60 hip joints accor-ding to HHS in 31.7 % excellent results were achieved, in 28.3 % good results, in 20 % satisfactory results and in 20 % poor results.

The authors did not find a positive correlation bet-ween painfulness of the joint and signs of aseptic rele-ase of the socket on X-ray examination.