Articulated bipolar vs. non-articulated conventional spacers: A comparative study of results from two-stage treatment of chronic septic arthritis in prosthetic or native hips

Abstract

IntroductionInfection is a serious complication of 0.2–0.7% of primary total hip arthroplasties (THA) and 1-22% of prosthetic revisions. The objective of our study was to compare two types of spacers (unipolar versus bipolar) for two-stage revisions of periprosthetic hip infections. The primary hypothesis was that bipolar spacers have fewer mechanical complications than unipolar spacers. The secondary hypothesis was that bipolar spacers decrease the rate of septic revisions and promote primary prosthesis reimplantation. Material and methodThis retrospective, monocentric, multi-operator study was carried out between January 2012 and July 2018, including patients operated on for septic arthritis of the native or prosthetic hip (two-stage procedure). The patients were divided into two groups: group A, including the articulated spacers and group B, including the unipolar spacers. We studied the complications of the spacers and the course of the infection over a minimum of two years. Functional status was assessed by the Postel Merle d’Aubigné (PMA) score, the Harris Hip Score (HHS) and pre- and postoperative patient satisfaction scores. ResultsWe collected data for 39 hips from 37 patients (mean age 63, 22 men and 14 women: 16 patients in group A, 21 in group B). We found no mechanical complications in group A versus 12 (52%) in group B. At 2 years, 93.8% of patients in group A no longer had any signs indicative of an active infection, compared with 71.4% in group B. In group A, the median PMA score increased from 5.5 (4–10.5) to 13.5 (12.5–15.5) and the HHS score from 27.5 (17–41.5) to 79 (64.5–89.5), postoperatively. In the final group B, the PMA score increased from 7 (6–9) to 14 (12–16) and the HHS score from 24 (11–41) to 72 (48–82) postoperatively. ConclusionThe use of articulated spacers in THA or septic THA two-stage revision significantly reduces the occurrence of mechanical complications in the short term, as well as the pain between the two procedures. Level of proofIV.