Successful femoral reconstruction with a fluted and tapered modular distal fixation stem in revision total hip arthroplasty

Background and Aims: Early results of fluted and tapered distal fixation stems used in reconstruction of deficient femora in femoral revision arthroplasty have been successful in small series. We evaluated the survival of the LINK MP Reconstruction Hip Stem and factors associated with survival using data from a nation-wide arthroplasty register. Materials and Methods: 408 femoral revisions using LINK MP Reconstruction Hip Stem were performed during 1994 to 2007. The mean age of the patients was 72.5 (range: 36-93) years and 63% were performed in women. Kaplan-Meier analysis and the Cox regression model were used for the survival analysis. The effects of age, sex and diagnoses were also studied. Results: The 9-year overall survivorship for the LINK MP Reconstruction Hip Stem was 75% (95% CI 70-80). Aseptic loosening was rare; the 9-year revision rate for aseptic loosening was only 3%, which coincides with earlier reports with shorter folllow-up. The most common reason for re-revision was dislocation of the prosthesis with or without malposition of the socket (67%). Indication for revision strongly affected the survival rate with revisions for dislocation having an over 3-fold and revisions for infection a 3-fold relative risk for re-revision compared to revisions for aseptic loosening. Increasing age slightly decreased the risk of re-revision but sex did not affect the survival. Discussion: Based on our findings, we conclude LINK MP Reconstruction Hip Stem, as an example of a fluted and tapered distal fixation stem, appears to solve many problems with implant fixation in femoral revisions. High number of dislocations suggests that special attention should be paid to correct center of rotation, to correct implant positioning and to need of constrained implants in case of deficient abductor mechanism.