Revision arthroplasty of the hip - Modularity of neck and metaphyseal components

Modular parts in femoral components used for hip arthroplasty are reported to be predilection sites for mechanical failure. The possible benefit of their use is therefore controversial. We report the outcome of 97 revision hip arthroplasties using a non-cemented femoral component with a modular metaphyseal part and an interchangeable neck (ProfemurA (R)). The femoral defects treated included Paprosky types I-III. The average follow-up was 5 years (range 3-10 years). No mechanical failure of the modular parts and taper connections has been observed so far. The percentage of patients with a balanced leg length increased from 32% preoperative to 65% postoperative. The mean leg length discrepancy could be reduced from 1.4 cm preoperative to 0.5 cm postoperative. A total of 5 re-revisions were required, including 2 cases of infection. The cumulative survival of the implants due to aseptic loosening was 96.5%. Because of the achieved results the use of the modular stem investigated in this study can be classified as safe and effective for revision hip arthroplasty. The interchangeable neck proved to be a useful completion of the revision system.