Role of joint aspiration before re-implantation in patients with a cement spacer in place

BACKGROUND: The usefulness of a mandatory joint aspiration before re-implantation in patients with a cement spacer already in place is unclear. AIM: To evaluate the role of culturing synovial fluid obtained by joint aspiration before re-implantation in patients who underwent a two-stage septic revision. METHODS: A retrospective observational study was conducted, including patients that underwent a two-stage septic revision (hip or knee) from 2010 to 2017. After the first stage revision and according to intraoperative culture results, all patients were treated with an antibiotic protocol for 6-8 wk. Following 2 wk without antibiotics, a culture of synovial fluid was obtained. The results of these cultures were recorded and compared with cultures obtained during re-implantation surgery. RESULTS: Forty-one patients (20 hip and 21 knee spacers) were included in the final analysis. In 39 cases, the culture of synovial fluid was negative, while in the remaining 2 cases (knee spacers) no analysis was possible due to dry tap. In 5 of the patients, two or more intraoperative cultures taken during the re-implantation surgery were positive. CONCLUSION: We found no evidence to support mandatory joint aspiration before re-implantation in patients with a cement spacer in place.