Introduction: Replacing a fused or ankylosed hip with a prosthesis has several advantages. It reduces the pain in the lumbar-sacral spine and the ipsilateral knee. It gives a better range of movement and leg length is restored.

Methods: In this study we present our experience of 50 cases of total hip arthroplasty in fused or ankylosed hips. Aetiopathogenesis was rhizomelic spondylitis in 35 cases, sequelae of coxitis in 2, posttraumatic in 4, Ankylosis in 6, and fusion in 3. For clinical assessment we used the Merle D’Aubignè score, and for radiographic evaluation we used the Gruen method of area subdivision.

Results: Of the 50 prosthesis implanted, 3 were removed due to aseptic loosening. The other were radiographically stable after an average follow-up of 12 years. Preoperative clinical scores were: pain (2.9), range of motion (2.5), and walking (2.1). At the latest exam the scores were: pain (5.5), motion (4.6), walking (4.5). Preoperative leg shortening was 3.5 cm, whereas at the latest exam it was 0.9 cm. Lumbalgia decreased notably in 62%.

Conclusions: Total hip arthroplasty may have advantages over fusion on one hand, but on the other it is technically more difficult and gives results that are inferior to common indications. It is therefore important to assess patients (time of fusion, age of patient, residual muscular function) preoperatively to obtain good results

Aims: The aim of this retrospective study is comparatively analysing cemented versus hydroxyapatite coated cementless þxation. A 10-year survival analysis of 2 patient cohorts operated by the same senior surgeons and with the same stem design was performed. Methods: Between 1990 and 2000, 1207 primary prostheses, 599 cemented and 608 cementless stems have been implanted. When mineral bone density and anatomic shape of the femur advised against inserting a cement-less stem a third generation cementing technique was chosen. In all cases an anatomic CoCr alloy stem and an alumina coupling were employed. Cementless stems were fully coated with hydroxyapatite. To provide homogeneity for preoperative diagnosis, only replacements for primary arthritis were considered. The remaining prostheses were 432 cemented and 366 cementless. The cumulative probability of revision for aseptic loosening of the stem was estimated by the Kaplan-Meier method. Results: 98.5% of the cemented stems and 96.7% of the cementless stems survived at 10 years, the difference between the 2 cohorts being statistically not signiþcant (p> 0.05). Conclusions: Using the same stem design and ceramic coupling, thus avoiding the confounding presence of polyethylene wears debris on study outcomes, allows for the reliable evaluation of stem þxation effectiveness. Noting that the evaluated survival rates are consistent with the literature, we are conþdent that at 10 years cementless stems performed as cemented.