Introduction and Aims: This paper presents a treatment plan for femoral stem revision that has been developed based on long-term studies of revision total hip replacement (THR) using cemented stems, cementless proximal fixation stems, cemented stems with impaction grafting and modular titanium long stems.
Method: The clinical and radiographic results of femoral stem revision were compared using the following techniques: 1) a standard or long cemented collarless double taper Exeter or CPT stems (CCDT stems) [n=190]; 2) a proximally porous coated mid to long cementless stem [n=56]; 3) two series of CCDT stems with impaction grafting n=34]; and 4) a modular grit-blasted titanium taper stem [n=13] used for severe cortical damage. Treatment decisions were made based on the age of the patient, the appearance of the pre-operative radiograph and the extent of bone deficiency at surgery. Follow-up was from 17 to two years.
Results: Only one hip was lost to follow-up. In the CCDT group, at a median follow-up of five years (range 2–17 years), two standard length stems and one long stem had been re-revised for loosening (1.5%) and seven stems had been re-revised for other reasons. Survivorship to re-revision for loosening at eight years was 95% (95%CI=85–100%) for both standard and long stems. There was a trend for better longer-term results for long stems. The extent of pre-operative bone loss did not influence results. For the cementless proximal fixation group, at a median follow-up of 10 years, re-revision of the stem for loosening occurred in 20%. Importantly, these poor results could have been predicted from short-term results. The initial series of femoral impaction grafting with CCDT stems and irradiated bone had a small incidence of stem loosening and periprosthetic fracture. The majority of stems subsided, but at a median follow-up of eight years there were no further re-revisions. In the second series, usually with non-irradiated allograft with mesh containment, there was minimal stem subsidence and no re-revision. The grit blasted titanium taper stem has dealt with periprosthetic fratures and severe proximal cortical loss, but with some cases of subsidence and femoral fracture.
Conclusion: Based on these results, our treatment plan for routine femoral revision in middle-aged and elderly patients without severe proximal deficiency is a polished CCDT long stem. In younger patients, impaction grafting is recommended, provided deficient bone is protected. Cementless modular stems are reserved for femurs with severe proximal cortical deficiency.