[Experience with the Walter-Motorlet/Poldi hybrid hip joint endoprosthesis in our department]

Patients with total hip replacement, in whom the hybrid prosthesis consisting of a Walter-Motorlet socket and a Poldi shaft was used, were followed up and the results were evaluated.

Eighty eight total hip replacements were carried out in 85 patients in the period from 1995 to 1997. Of these, 64 were evaluated at the follow-up lasting on a average 67 months; 14 patients who failed to come for a check-up were excluded from the study.

All patients were operated on from the Watson-Jones approach. They underwent clinical examination, outcome assessment by the Harris classification and X-ray examination in anterior-lateral and axial projections.

The average age of patients at the time of surgery was 58.3 years. Indications for the operation included primary arthritis in 45.3%, post-dysplastic arthritis in 31.3%, secondary arthritis in 10.9% and trauma in 12.5% of the patients. The results evaluated according to the Harris classification system were excellent or very good in 83%, satisfactory in 6% and poor in 11% of the replacements. On subjective evaluation, the joint free from pain had 37.5% and slight paint was experienced by 48.5% of the patients. Para-articular ossification developed in 39% of the patients. A total of five sockets (7.8%) and three shafts (4.7%) showed signs of aseptic loosening.

This study showed worse outcomes of total hip replacement, as classified by the Harris system, that those reported in the relevant Czech or foreign literature. Our results of pain evaluation were also worse than those reported by the Czech an foreign authors. The diagnoses leading to total hip replacement and their frequency were in agreement with the foreign literature data and this was also true for the occurrence of para-articular ossification. In the reports by the Czech authors cited, however, the reasons for hip replacement, in terms of diagnosis frequency, were different and the development of para-articular ossification was recorded in fewer cases.

The occurrence of soft linings of the socket was high (in 51% of the patients) and became a prerequisite for subsequent socket loosening. This finding was also in accordance with the results reported in the literature quoted.