EXTENSIVE TROCHANTERIC OSTEOTOMIES VS. PERIOPERATIVE FEMORAL FRACTURES DURING STEM REMOVAL IN REVISION THA

Abstract

Introduction: The number of revision Total Hip Arthroplasties (rTHA) continues to rise in an ageing population. High fracture rates reported point out that stem removal is associated with substantial surgical complications. Extensive Trochanteric Osteotomies (ETO) may facilitate stem removal; however, it has also been associated with hazards like increased incidence of non-union, fracture of the osteotomy fragment and stem subsidence. It is not yet clear if a permissive indication for ETO may lead to better postoperative results, than removing stem and cement from the top of the femur eventually causing fractures.

This study describes our experience, comparing peri-operative femoral fractures during stem removal with ETOs in rTHA.

Patients & Methods: Between 1992 and 2004 45 perioperative fractures during rTHA were compared to a collective of 28 ETOs. Pre-Op and after a follow-up period of 32 months (range, 21.6 – 76 months) patients were examined clinically and radiographically. Investigation parameters were Harris-Hip score, SF-36 health score, function (0 – 6) and pain (0 – 10) score, limp, postoperative complications, implant survival and radiographic parameters (stem and trochanter migration, stem alignment, bone union). Fractures were graded using the Vancouver classification.

Results: Harris hip score increase was 31 points (p = 0.004) in ETO patients and 17 points in patients with femoral fractures during stem removal. Increase for function and pain was 1.5 points and 4.4 points in ETO patients and 2 points and 3 points in patients with perioperative femoral fractures. SF-36 health score showed better increases in patients with ETOs. Joint luxation occurred in 3 (6.7%) patients with perioperative fractures and once (3.6%) in the osteotomy group. Infections were more frequently after ETO. 2 patients showed Trendelenburg gait after ETO, but were satisfied with the operation. 1 (3.6%, 12 mm) stem in the ETO group and 3 (6.7%, mean 15 mm) stems in the fracture group subsided slightly. No cable failure was detected in the ETO group, but 2 (4.4%) in the fracture group. 1 osteotomy fragment and 3 femoral fractures showed nonunion and needed re-revision. Every implanted stem had excellent alignment within standard error of ± 3°.

Discussion: Our results suggest that permissive indication for ETO in rTHA may lead to better postoperative results. Especially in patients with poor bone stock, where intraoperative fractures may likely occur, proper implant exposure and rigid fragment fixation may be crucial for success. Although the ETO might be associated with nonunion and limp, this study, as well as others, demonstrates that these observations do not necessarily compromise patient satisfaction. Conclusively, risking femoral fractures during stem removal is prejudicially, compared to proper, extensive femoral osteotomies in rTHA.