Cement spacer as definitive management for postoperative ankle infection.

Background: Postoperative infection can be a devastating complication of ankle replacement and arthrodesis surgery. Management consists of eradication of the infection and either, revision of the initial surgery or some form of salvage procedure. There are instances however when the patient is asymptomatic, medically unfit, or the local tissue is too tenuous to warrant performing additional surgery. We conducted a retrospective review of the outcome of the use of an antibiotic impregnated cement spacer as the definitive procedure in this kind of patient.

Methods: There were nine patients with post operative deep ankle infection following surgery who did not undergo subsequent revision surgery. The initial surgeries were either total ankle replacement (TAR) (n = 6) or ankle arthrodesis (n = 3). The indications for the retention of the cement spacer were patients who were asymptomatic following insertion of the cement spacer, did not desire further surgery, or were medically unfit for further surgery. The patients all underwent removal of hardware or implants, debridement, and insertion of an antibiotic impregnated cement spacer. Six weeks of intravenous antibiotics were administered according to culture sensitivity results. Patients were followed up closely for complications (wound dehiscence, spacer migration, bone loss), resolution of infection, functionality, and satisfaction.

Results: The average time of cement spacer retention was 20.1 months, ranging from 6 to 62 months. The most common infecting organisms were Staph. Aureus (n = 3) and Staph. Epidermidis (n = 3). One patient had wound complications, possibly due to the proximity of the cement spacer to the anterior skin surface. One patient had a repeat infection at 52 months. The most common co-morbidities were rheumatoid arthritis (n = 3) and diabetes (n = 2). At final followup, seven patients still had a retained cement spacer and two had subsequent below knee amputations (BKA) performed as a result of delayed complications. Review of the X-rays revealed two patients with loosening and migration of the cement spacer. No patients had signs of excessive bone loss. All patients with a retained antibiotic cement spacer were mobile and able to perform basic activities of daily living with minimal discomfort.

Conclusion: The long-term use of antibiotic impregnated cement spacers following postoperative ankle infection is a reasonable option in the low demand patient with surgical or medical co-morbidities.