Abstract
We reviewed the outcome of prosthesis-to-bone fixation of the rough titanium femoral stem of an Ultraloc prosthesis (Zimmer, USA).
Between 1989 and 1991, 41 of 55 patients were traced for long-term review at a mean of 107 months (55 to 139). The primary pathology was avascular necrosis in 18 patients, osteoarthritis in 16, ankylosing spondylitis in two and Perthes’ disease in one, and there were two cases each of trauma and dysplasia. There was an equal number of men and women, whose mean age at operation was 47 years (24 to 66).
Radiological assessment of the stems revealed well-fixed stems in 40 patients (97.6%). In 20 stems small granulomata due to polyethylene wear were found in Gruen zones 1 and 7, and in one stem in zones 1, 6 and 7. Only one stem required revision for loosening (done at 59 months), but cups (48.8%) were loose. Three patients required revision owing to polyethylene wear and one for sepsis. In all four cases, removal of the stem was extremely difficult. The remaining 16 hips await revision.
Although the results obtained using an Ultraloc prosthesis are poor, from the point of view of fixation the stem has functioned successfully. However, the formation of granulomata causes cup loosening.
The abstracts were prepared by Professor M. B. E. Sweet. Correspondence should be addressed to him at The Department of Orthopaedic Surgery, Medical School, University of Witwatersrand, 7 York Road, Parktown, Johannesburg, 2193 South Africa
