ANTIBIOTIC-LOADED PREFORMED PMMA SPACER FOR TWO-STAGE REVISION OF INFECTED TOTAL HIP REPLACEMENTS

Abstract

Introduction: In two-stage revision of an infected total hip replacement a preformed temporary antibiotic-loaded polymethylmethacrylate spacer may be required in order to allow weightbearing and joint motion while ensuring antibiotic local release.

Methods: 29 patients with infected hips were treated by a two-stage procedure including removal of prosthesis and implantation of a spacer. The device comprised a stem with 3 available head sizes pre-coated by bone cement supplemented with gentamicin (2.5% w/w) and vancomycin (2.5% w/w). Joint motion and weight-bearing were allowed when the bone stock ensured an adequate stability to the spacer. Systemic antibiotics were administered for 8 weeks. The spacer remained in situ for an average of 155 (range 70–272) days. Reimplantation was performed when recovery of clinical and serological signs of infection was obtained. Patients’ evaluation included clinical assessment (HHS), standard x-ray and laboratory parameters.

Results: mean follow-up was 52 months (range 36–100). Healing of the infection was obtained in 27/29 cases (93.1%). 5 patients required resection-arthroplasty (2 persistent infections, 2 inadequate bone stock, 1 recurrent infection). In 4 cases the spacer dislocated, being treated by non-surgical reduction. The reimplanted patients (24) showed no clinical or laboratory signs of infection recurrence, with a mean HHS score of 79 (range 53 to 100); no radiographic signs of loosening were observed.

Discussion: the use of a preformed antibiotic-loaded spacer in two-stage revisions, allowing a local antibiotic release together with some degree of joint motion, appears to enhance infection’s treatment improving patients’ quality of life and functional recovery.