Two stage hip revision arthroplasty using digital polarization microscopy and intraoperatively produced second generation spacers

Abstract

The results of two stage hip revision arthroplasty depend a great deal on accuracy in differentiating septic component instability from aseptic one. Conventionally, it is based on microbiological assessment of joint aspirate or samples from the wound. The results are available in 8-10 days, and in case of anaerobic infection as late as in 2-3 weeks. Using laser sources for diagnosing the septic instability of hip endoprosthesis components showed spectropolarimetry to have the highest sensitivity, specificity, and accuracy: its sensitivity reached 92-93%, specificity – 82-86%, and accuracy – 88-89%. The result is ready in 1-2 hours. In 2012, new reusable molds for intraoperative production of cement spacers with the antibiotics relevant to the patient’s antibioticogram were designed by us. Such spacer contained the antibiotics for which the patient’s infection was susceptible, and resembled the shape of a monopolar endoprosthesis. Aim of the study was to improve the results of treatment for septic instability of hip endoprosthesis or its components by using digital polarization microscopy of synovial fluid, and intraoperative production and application of second generation antibiotic impregnated cement spacers in accordance with the patient’s antibioticogram.