The work is dedicated to improving the diagnosis and differentiation of aseptic and septic forms of arthritis, such as reactive synovitis in osteoarthritis II-III, postoperative aseptic synovitis, and septic arthritis by developing and implementing a new technology using laser polarization microscopy, phase-microscopic, spectrophotometric methods and spectropolarimetric smears of synovial fluid. The study involved 85 patients, comprising the first group of 44 patients with osteoarthritis II-III with reactive synovitis in the knee proved by clinical, laboratory, biochemical and instrumental diagnostic methods, the second group of 29 patients with aseptic synovitis of the knee after surgery, and the third group of 12 patients with septic arthritis of the knee joint. Based on their assessment, the relationship was established between the verified diagnosis of patients in different groups, the ranges of statistical momenta of 1-4 orders of magnitude characterizing parameters of microscopic images of synovial fluid layers, and the absorption spectra of these samples. Comparing the sensitivity, specificity and accuracy of polarimetric methods, Stokes-polarimetry, spectropolarimetry, phasometry in the diagnosis and differentiation of the above pathological conditions in the jointsrevealed that spectropolarimetry posesses the highest sensitivity, specificity, and accuracy: sensitivity was 92-93%, specificity - 82-86%, and accuracy - 88-89%. However, the method is technically quite complex and therefore takes the longest time to perform (1.5-2 hours). The method of phasometry of laser microscopic images of synovial fluid has the sensitivity of 82-83%, specificity of 73-76%, and accuracy of 78-79%. Technical implementation of the phasometry of laser microscopic images of synovial fluid is much simpler than spectropolarimetric method and requires less time for data processing (45-60 min.) Polarimetric method, Stokes polarimetry, generally showed the lowest sensitivity rates of 66-75%, specificity of 61-66%, and accuracy of 61-71%, but is the base for the phasometric and spectropolarimetric assessment.
