Оptical Spectroscopy in the Diagnosis of Intra-articular Injuries
Condition: Cartilage Destruction
Study type: Observational

Summary: 
      Intra-articular joint injuries are the most common and prognostically unfavorable in case of
      untimely or erroneous diagnosis, which leads to a significant violation of the quality of
      life and activity of patients. For example, untimely diagnosis and determination of the
      degree of damage to the subchondral bone can lead to progression, namely, an increase in the
      edema zone with transformation into an irreversible process - avascular necrosis of the bone.
      Mistakes in diagnosing subsynovial injuries of the ligamentous apparatus and assessing its
      functional viability can lead to the development of chronic joint instability, chronic
      synovitis, and progression of intraarticular destruction.

      Methods of early and accurate diagnosis allow timely and personalized treatment, they are
      aimed at preventing the development of complications and the need for repeated expensive and
      often disabling operations. The issue of developing the method of intraoperative navigation
      with the use of quantitative assessment methods in operations on the musculoskeletal system
      is also relevant.

      In this regard, the methods of optical spectroscopy and optoacoustics proposed in the
      project, which can solve the above problems, are of particular relevance.

      Thus, the scientific problem to be solved by the proposed project is the development of
      optical and optoacoustic spectroscopy methods for biomedical diagnostics. The development of
      new methods and tools capable of detecting and characterizing both early and hidden
      predictors of the possible progression of osteoarthritis will prevent or reduce the risks of
      possible complications and irreversible intra-articular changes.
    

Detailed description: 
      The objectives of this work is to create new optical methods for in vivo analysis of the
      state of cartilage tissue.

      Methods: A prospective study will develop an instrument that implements two optical methods
      for assessing the condition of cartilage tissue: diffuse reflectance spectroscopy (DRS) and
      near-infrared fluorescence spectroscopy. Explants (knee joint) will be used as experimental
      material. To assess the diagnostic capabilities of optical spectroscopy methods, studies of
      the mechanical characteristics of cartilage will be carried out simultaneously with the
      optical characteristics. Cartilage mechanical parameters will be measured using a Mach-1
      v500c indenter (Biomomentum, Laval, QC, Canada) equipped with a three-axis dynamometer. The
      direction of the normal to the sample will be measured with a spherical indenter; a needle
      puncture will be performed to assess the thickness of the explant tissue. Measurements will
      determine the Young's modulus, the direction of the normal and the thickness of the
      cartilage. This work is supported by the Russian Science Foundation (grant no. 21-79-10325).

      An indentation will be performed to determine the mechanical parameters of the cartilage at
      different points and to obtain DCR spectra of the cartilage in the wavelength range of
      850-1050 nm.Analysis of changes in the properties of water in the cartilaginous tissue of the
      knee joint in normal and pathological conditions will be supplemented by a study of its own
      IR fluorescence. In preliminary experiments, it was found that different parts of the
      cartilage of different explants have different levels of red fluorescence at different stages
      of degeneration, however, in order to draw conclusions, it is necessary to expand the number
      of measured samples to assess the reliability of the results of the observed differences.

      In the course of the work, a mobile unit will be developed that implements the methods of
      fluorescence spectroscopy in the near infrared range and DLS, and the mechanical properties
      of explants will also be studied. In the future, it is planned to use the developed technique
      for assessing the state of the cartilage intraoperatively.

      Before conducting the experimental work, it is planned to write a systematic review on the
      research topic.
    

Observational model: Ecologic or Community
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        Work will be carried out with biological samples of bone and cartilage tissue in compliance
        with all ethical standards: work with explants (38 samples), as well as in vivo
        measurements - intraoperatively (10 patients).
      
Keywords: cartilage; regeneration; destruction; knee; intraarticular lesions