Abstract
Traditionally the most commonly used femoral implants in revision hip arthroplasty are distally fixed monoblock designs. Ability to adjust length version and offset is limited once the stem is inserted. Revision using this type of stem has been associated with high incidence of complications including dislocation. Modular distally fixed femoral implants have been developed in order to decrease the complication rate by restoring normal hip mechanics. The goal of this study is to evaluate the performance of these type stems as it relates to fixation and instability.
Seventy three revisions were done using three modular stem designs. All stems were common in design featuring a proximal cone shape body attached by a taper to a fluted distal stem. Revisions were performed for loosening, periprosthetic fractures and infections. Most revisions were in patients with severe bone loss. Follow-up range from 6 to 72 months with an average of 30 months. Parameters evaluated included fixation and instability.
In this series we obtained excellent bony fixation as well as an acceptable dislocation rate in revision of severely compromised femurs. There were no stem fractures at the modular junction at early follow-up. Dislocation was readily managed by revision of the proximal portion of the stem without compromising distal fixation. This study demonstrates that modular approaches can be used successfully.
The abstracts were prepared by Editorial Secretary Jean-Claude Theis. Correspondence should be addressed to NZOA at Department of Orthopaedic Surgery, Dunedin Hospital, Private Bag 1921, Dunedin, New Zealand.
