Femoral revision with a primary cementless stem

Abstract

IntroductionThe use of a primary cementless component is a tempting option for revision total hip arthrosplasty (reTHA), however, the results of this type of revision have not been clearly determined. The goal of this retrospective study was to determine: if revision with a primary anatomical cementless femoral stem gives adequate bone fixation; the rate of secondary subsidence or recurrent loosening; the survival rate with this device. HypothesisRevision with a primary anatomical cementless femoral stem results in a low rate of subsidence and recurrent loosening. Materials and methodsThis retrospective series of 43 reTHA performed between 1994 and 2012 included 43 patients, mean age 66 years old (37–90) with a minimum follow-up of 24months. There were grade 1 (n=24) or 2A (n=19) bone defects according to the Paprosky classification. The causes of revision were: aseptic loosening in 27, septic loosening in 6, malposition of the implant in 7 and periprosthetic fractures in 3. Clinical (Postel Merle d’Aubigné [PMA] and Harris scores), and radiological (subsidence) assessment was performed, as well as survival analysis (with a 95% confidence interval). ResultsAll components were changed through posterolateral approach without femorotomy. In four cases de-escalation (use of a primary component for secondary revision of a prior revision component) was performed. There were no perioperative fractures or perforations. After a mean 47months (24–134), the mean PMA score increased from 10 (5–15) to 16 (11–18), and the Harris score from 58 (20–80) to 85 (66–96). Radiological assessment did not show any extensive radiolucencies or secondary subsidence. Only 3 components were placed in a varus position, with no clinical consequences. One patient had subsequent revision for recurrent dislocations. Estimated survival at 80months by Kaplan-Meier analysis was 85% (CI 95%: 64–100%). DiscussionThere are very few studies in the literature (7 series) on this topic, which shows the reluctance of surgeons to use this technique. Placement of a primary femoral stem requires good metaphyseal bone quality for primary stability. Thus, the indication is limited to Paprosky 1 and 2A stages. Revision surgery must be performed by endofemoral approach requiring good preoperative planning, as well as knowledge of the explanted component and a revision component must be available, if necessary, in the operating room. Level of evidenceRetrospective study, level 4.