Usefulness of Culturing the Periprosthetic Membrane or Neosynovium for the Diagnosis of Infection During Hip and Knee Revision Arthroplasty.

Introduction: Identification of microorganisms is critical for correct management of an infected arthroplasty. Our hypothesis is that the culture yield depends on the location around the prosthesis from which samples are obtained.

Methods: This prospective study included 298 revisions of the hip (123) and knee (175). We compared the yield of the intraoperative samples obtained, which included synovial fluid (two), neosynovium (two), and periprosthetic membrane (two).

Results: Cultures were positive in 28 cases, in which 15 had the same diagnosis considering either the neosynovium or the membrane, and there were 3 cases in which the infection could have been diagnosed only by considering the combination of both. In all, there were 8 cases in which the infection might have been misdiagnosed unless considering a combination of both solid tissue samples (P = 0.004).

Conclusions: The yields of the periprosthetic membrane and neosynovium do not differ significantly, and we recommend considering a combination of both.

Level Of Evidence: Diagnostic Level II.