Оptical Spectroscopy in the Diagnosis of Intra-articular Injuries

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.

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.

Eligibility Criteria:
Inclusion Criteria:

1. Written informed consent of the patient to participate in the study.
2. The age of the patient is from 18 to 85 years.
3. Gender male and female.
4. The patient has intra-articular injuries of the knee joint.

Exclusion Criteria:

1. Refusal to participate in the study and to sign informed consent.
2. The age of the patient is less than 18 and more than 85 years.
3. Pregnancy, lactation.
4. The presence of severe concomitant somatic pathology (diseases of the cardiovascular system, lungs, liver and kidneys), decompensated diabetes mellitus.
5. Oncological diseases.
6. Mental illness.
7. Alcohol abuse or drug use.
8. Chronic viral and bacterial infections in the acute stage.