Near infrared spectroscopic evaluation of biochemical and crimp properties of knee joint ligaments and patellar tendon

A Review of Chronic Lateral Ankle Instability and Emerging Alternative Outcome Monitoring Tools in Patients following Ankle Ligament Reconstruction Surgery

Ankle sprains are exceedingly common injuries in both athletes and the general population. They account for 10 to 30% of all sports injuries. Although the vast majority of lateral ankle ligament injuries respond successfully to conservative management, the absolute number of those that progress to chronic lateral ankle instability (CLAI) remains considerably important. This condition is characterized by persistent symptoms and may be associated with short-term and long-term complications and functional deficits. There is still a lack of ideal postoperative management of CLAI patients. Furthermore, an evidence-based rehabilitation phasing does not exist and most of the published studies regarding this subject suggest some protocols based on a wide variety of functional assessment scores and other modalities that are not accurate enough. Moreover, the literature that assesses the ability to return to work (RTW) and return to sport (RTS) in the general population and athletes operated for CLAI most commonly shows aggregated results with global rates of RTW or RTS without describing a detailed timeline based on the readiness of patients to return to each level of activity. Although stress radiographs and MRI have been assessed as potential tools to improve postoperative management of CLAI patients, the first modality is limited by its low sensitivity to detect laxity and the second one by its static character and its inability to predict neither the healing process phase nor the mechanical properties of the repaired/reconstructed ligaments. Bioelectrical impedance, mechanical impedance and near-infrared spectroscopy are non-invasive methods of measurement that could be potential assessment tools to help surgeons improve the postoperative management of patients after CLAI surgery.

Application of diffuse optical back reflection spectroscopy for determining articular cartilage thickness in a clinical setting

PURPOSE

Develop a spectroscopic method to assess cartilage thickness during the arthroscopic examination.

METHODS

Currently, arthroscopy assesses cartilage damage visually; outcomes are based on the surgeon's subjective experience. Light reflection spectroscopy is a promising method for measuring cartilage thickness based on the absorption of light by the subchondral bone. In the presented study, in vivo diffuse optical back reflection spectroscopic measurements were acquired by gently placing an optical fibre probe on different locations of the articular cartilage of 50 patients during complete knee replacement surgery. The optical fibre probe consists of two optical fibers with a diameter of 1 mm to deliver the light and detect back-reflected light from the cartilage. Centre to centre distance between the source and the detector fibers was 2.4 mm. Actual thicknesses of the articular cartilage samples were measured under microscopy using histopathological staining.

RESULTS

Using half of the samples in the patient data, a linear regression model was formed to estimate cartilage thicknesses from the spectroscopic measurements. The regression model was then used to predict the cartilage thickness in the second half of the data. The cartilage thickness was predicted with a mean error of 8.7% if the actual thickness was less than 2.5 mm (R2 = 0.97).

CONCLUSION

The outer diameter of the optical fibre probe was 3 mm, which can fit into the arthroscopy channel and can be used to measure the cartilage thickness in real-time during the arthroscopic examination of the articular cartilage.