The Role Of Nir Spectroscopy In The Treatment Of Osteoarthritis

INTRODUCTION

Arthritis is a disease that causes damage in your joints. The most common type of arthritis, osteoarthritis (OA) is a degenerative joint disease that primarily affects cartilage. It is one of the most prevalent worldwide health problems in orthopedics and can affect many joints; due to its complicated anatomical structure, the knee is the most affected joint (Figure 1).

Osteoarthritis is characterized by osteophyte production and a gradual loss of articular cartilage, which causes chronic discomfort and functional limitations in affected joints. Numerous factors, including genetic predisposition, poor joint posture, aging, malnutrition, excessive use, hypomobility, excessive body weight,… can contribute to the development of osteoarthritis.

Figure 1.  Anatomical structure of the knee joint

METHOD

Cartilage injuries may result in acute lesions, which without intervention may progress to post-traumatic osteoarthritis (PTOA). Several techniques are available for cartilage repair, with recent research suggesting that pharmaceutical interventions may be effective in preventing the onset or halting the progression of PTOA if the injury is detected early. Thus, characterization of cartilage integrity and disease progression at the early disease stages is crucial for effective management and treatment of PTOA.

Current standards for the diagnosis and treatment of osteoarthritis rely on radiographic imaging to detect hardening of the subchondral layer. However, a significant issue in osteoarthritis research is that the condition is rarely identified until joint abnormalities cause pain and are present on X-rays. Since early-stage osteoarthritis generally does not manifest clinically, cartilage tissue from this stage of the disease is used for specific studies.

NIR spectroscopy is a vibrational spectroscopic technique that is sensitive to specific molecular species containing CH, NH, OH and SH bonds, which constitute the fundamental chemical structure of biological tissues. NIR has been shown to be sensitive to micro- and macroscopic properties of cartilage and a typical spectrum incorporates latent information on structural, compositional and morphological properties of the tissue. In addition, NIR spectroscopy is a rapid, non-destructive optical technique that penetrates deep into soft tissues, permitting full-depth cartilage probing. By analyzing the near-infrared range (between 650 nm and 1900 nm), researchers can quantify joint damage progression and evaluate treatment during in vivo arthroscopies.

Variations in the optical response of the injured joints, as tissue degeneration progresses, is mostly characterized by an overall increase in absorbance across the NIR spectral range (Fig. 2) and using near infrared (NIR) spectroscopy to monitor osteoarthritis progression.

Figure 2. Representative raw (a), 1st derivative (b) and 2nd derivative (c) cartilage NIR spectra from control (sham) and progressively degenerating joint samples. The derivative spectra show consistent changes with progression of tissue degeneration.

Spectral data below 5250 cm−1 were excluded due to spectral saturation in the 1st overtone water peak and combination region of the NIR spectral range.

Near-Infrared (NIR) spectroscopy plays a significant role in the treatment and management of osteoarthritis through various applications:

1. Non-Invasive Assessment

NIR spectroscopy allows for the non-invasive assessment of joint tissues. It can provide information about the biochemical composition of cartilage and synovial fluid, enabling early detection of changes associated with osteoarthritis.
2. Biochemical Analysis

NIR spectroscopy can analyze the concentration of key biomarkers related to cartilage degradation and inflammation, such as glycosaminoglycans (GAGs) and collagen. This helps in monitoring the progression of OA and the effectiveness of treatments.

3. Monitoring Treatment Efficacy

By using NIR spectroscopy, healthcare providers can evaluate the effectiveness of various treatment modalities, including physical therapy, pharmacological interventions, and surgical options. Regular monitoring can help tailor treatments to individual patient needs.

4. Research and Development

NIR spectroscopy is used in clinical research to develop new therapeutic agents and strategies for OA. It aids in understanding the biochemical changes that occur during disease progression and treatment response.

5. Predictive Analytics

Integrating NIR data with machine learning algorithms can enhance predictive analytics for OA progression, helping clinicians make more informed decisions regarding interventions and lifestyle changes.
 

BUILD SYSTEM

NIR spectroscopy relies on the absorption, reflection, or transmission of near-infrared light. Molecules in the sample absorb specific wavelengths of NIR light due to their vibrational modes.

The DH-2000 of Ocean Optics (Ocean Insight) is a light source offers stable, continuous output from 215-2500 nm. Using a combination of deuterium and halogen lamps, the DH-2000 is flexible and ideal for measuring a sample that has multiple features in different spectral regions or for analyzing a variety of different samples

Figure 3. Light source: DH-2000

NIRQuest a spectrometer of Ocean Optics is a high Sensitivity and Low Noise. It tapping into a feature-rich spectral response to gain insights into subsurface sample characteristics with a wavelength range from 900nm to 2450nm. The NIRQuest spectrometer is compact, versatile, and compatible with Ocean Insight light sources and accessories.

Figure 4. Near-Infrared Spectrometer: NIRQuest of Ocen Insight

CONCLUSION

In the medical field alone, light is used to monitor health status, perform diagnostic testing, assist in the treatment of chronic wounds, and detect and fight cancer, and new discoveries that advance medical science are made every day. During arthroscopic surgery, the NIRS system can be used to assess bone health in real time. Surgeons can make informed decisions based on the NIRS measurements, potentially improving patient outcomes. By characterizing bone tissue, NIR spectroscopy contributes to improving arthroscopic surgery standards for osteoarthritis treatment. Remember that NIR spectroscopy provides valuable insights without damaging the sample, making it a vital tool in biomedical research and clinical applications.