The development of confocal arthroscopy as optical histology for rotator cuff tendinopathy

J.P. Wu, M. Walton, Allan Wang, P. Anderson, Tao Wang, T.B. Kirk, Minghao Zheng

    Research output: Contribution to journalArticle

    5 Citations (Scopus)

    Abstract

    © 2015 Royal Microscopical Society. MRI, ultrasound and video arthroscopy are traditional imaging technologies for noninvasive or minimal invasive assessment of the rotator cuff tendon pathology. However, these imaging modalities do not have sufficient resolution to demonstrate the pathology of rotator cuff tendons at a microstructural level. Therefore, they are insensitive to low-level tendon diseases. Although traditional histology can be used to analyze the physiology of rotator cuff tendons, it requires biopsy that traumatizes the rotator cuff, thus, potentially comprising the mechanical properties of tendons. Besides, it cannot offer real-time histological information. Confocal endoscopy offers a way to assess the microstructural disorder in tissues without biopsy. However, the application of this useful technique for detecting low-level tendon diseases has been restricted by using clinical grade fluorescent contrast agent to acquire high-resolution microstructural images of tendons. In this study, using a clinical grade sodium fluorescein contrast agent, we have reported the development of confocal arthroscopy for optical histological assessment without biopsy. The confocal arthroscopic technique was able to demonstrate rotator cuff tendinopathy in human cadavers, which appeared macroscopically normal under video arthroscopic examinations. The tendinopathy status of the rotator cuff tendons was confirmed by corresponding traditional histology. The development of confocal arthroscopy may provide a minimally invasive imaging technique for real-time histology of rotator cuff without the need for tissue biopsy. This technique has the potential for surgeons to gain in real time the histological information of rotator cuff tendons, which may assist planning repair strategies and potentially improve intervention outcomes. Lay description: The rotator cuff tendons connect a group of muscles to the humeral head, which generate arm movement and maintain the glenohumeral joint centre of rotation. Dysfunction of this system may lead to rotator cuff or "impingement" pain. This is the second most common musculoskeletal condition, after neck and back pain and represents a significant economic burden on healthcare resources. The collagen structure and organisation are crucial to the tensile strength of rotator cuff tendons. Normal rotator cuff tendons contain type I collagen fibres, which are orientated longitudinally, allowing the maximum tensile properties of the tissue. Rotator cuff tendon tendinopathy is characterised by disruption of the normal collagen structure and origination patterns, decreasing the tensile strength of the tendons. Tendinopathy is believed to be one element responsible for the generation of rotator cuff pain. Magnetic resonance image (MRI), ultrasound and video arthroscopy are traditional imaging techniques for assessing rotator cuff tendon pathology. MRI and ultrasound are non-invasive imaging assessment techniques while video arthroscopy is regarded as "gold standard" for intra-operative assessing rotator cuff tears. These imaging modalities however do not possess sufficient imaging resolution to assess the microstructural changes in tendinopathy. Traditional histology may be used to confirm the pathology of rotator cuff tendons at a microscopic level, however it requires biopsy, which traumatises the rotator cuff, compromises the mechanical properties of tendons and cannot offer real time histological information. Confocal arthroscopy utilises a 6.3 mm imaging probe for acquisition of 3D high-resolution visualisation of the microstructure of a tissue without biopsy. Previous studies using the technique for assessing chondral and connective tissues have required a non-clinical grade fluorescent contrast agent, which has restricted the clinical applications of the technique for orthopaedics. In this study we have further developed the technique to use a clinical grade sodium fluorescein contrast agent. We have demonstrated that confocal arthroscopy can be successfully used as optical histology to demonstrate rotator cuff tendinopathy in human cadavers, which appeared macroscopically normal under video arthroscopic examinations. The tendinopathy status of the rotator cuff tendons was confirmed by corresponding traditional histology. The development of confocal arthroscopy may provide a minimally invasive imaging technique to acquire real time histological information about the rotator cuff without the need for a tissue biopsy. This information has the potential to be a valuable additional resource for surgeons and may assist in planning future repair strategies and potentially improve intervention outcomes. Journal compilation
    Original languageEnglish
    Pages (from-to)269-275
    JournalJournal of Microscopy
    Volume259
    Issue number3
    DOIs
    Publication statusPublished - 2015

    Fingerprint Dive into the research topics of 'The development of confocal arthroscopy as optical histology for rotator cuff tendinopathy'. Together they form a unique fingerprint.

    Cite this