[5- to 8-year results of total hip endoprosthesis implantation with the Müller straight shaft prosthesis (cemented TiAlNb shaft)].

The aim of this study was to obtain mid-term results after total hip arthroplasty (THA) with cemented titanium stems. In all, 184 patients with a total of 202 THAs (cemented titanium stem) were clinically and radiologically examined after an average follow-up of 6 years (5-8). The recruitment was 86%. The Harris score was determined clinically. Radiologically, the directly postoperative radiographs were compared to the control radiographs according to the recommendations of Gruen et al. and Johnston et al. In 2 cases (1%) septical complications appeared after 2 years, which were treated in two-stage surgery. To date, revisions after loosening have been carried out in 3 cases (1.5%). This is equivalent to a revision rate of 2.5%. Three further cases showed evidence of loosening in more than 5 radiolucent lines (RLL), according to Gruen, making close-meshed controls necessary. Clinically, in all of the 6 cases of aseptic loosening, the Harris score remained above 80 points. In 36 cases, more than one RLL, compared to the postoperative radiographs, was ascertained and mainly found in zones 1, 7, 8, and 14. Substantial subsidence or varus could only be observed in one case. The clinical results in the Harris score were good or excellent in 78% and satisfactory in 20%. With an average of 75 at the time of follow-up, the age of the patients was, according to the indication that only patients above age 60 are to receive cemented-stem prostheses, clearly advanced. The body weight was significantly higher (82 kg; d = 2.4) in those 6 patients having evident RLL, than in patients without RLL. The ratio body weight to surface of the stem was especially different (1.5 kg/cm2 versus 1 kg/cm2; P < 0.005) in the two groups. This did not apply to sex or activity of the patient, size or kind of stem, Harris score, ectopic ossification, or body weight index. The biggest possible stem should be implanted. Not all cemented titanium stem prostheses are necessarily affected with a high rate of loosening at a mid-term follow-up.