Scanning electron microscopy examination of tendon biopsies in healthy horses and patients with different stages of tendon healing.

Abstract

EinleitungErkrankungen der Beugesehnen stellen bei Sportpferden aufgrund des langwierigen Heilungsverlaufes und der hohen Rezidivneigung ein bedeutendes orthopädisches Problem dar. Scanning electron microscopy examination of tendon biopsies in healthy horses and patients with different stages of tendon healing.In this study core biopsies of 12 healthy flexor tendons and 40 flexor tendons at different stages of tendopathia (tendonitis) were investigated. The biopsy was taken in vivo with an automatic biopsy device and a 20 G (0,9 mm) needle. The harvested tissue was 1,6 cm long and was examined by scanning electron microscopy (SEM) at a 1:5000 magnification. The fibril architecture of each biopsy was objectively evaluated by a double score system that represented the fibril organisation and fibril diameter (texture-value and diameter-value). The healthy tendons had an average texture-value of 1,3; the tendopathia group had a significantly deviating average diameter value of 2,62. Tendons with completed maturing phase (>120 d), still having symptoms of tendopathia (n=18), had a significantly deviating texture-value and a low significantly deviating diameter-value to tendons with completed maturing-phase but without symptoms of tendopathia (n=7). Further there was a significant difference between the texture-value of healthy tendons (n=12) and matured tendons without symptoms of tendopathia (n=7). According to the results of clinical and sonographic pre-examination, the typical fibril organisation in the different stages of healing could be shown in the biopsy tissue. Thus a tendon lesion could be pathologically classified by the microstructure in vivo. In future the SEM examination of tendon biopsy could develop as an important addition to current diagnostic, especially in ambiguous sonographic cases. The described method could be an instrument, investigating clinical, sonographic and micromorphological findings in the tendon and their correlation to mechanical properties after tendon injury.

Serial superficial digital flexor tendon biopsies for diagnosing and monitoring collagenase-induced tendonitis in horses

“…They were also similar to those described by Buck et al (2002), who observed a significant difference in texture-values comparing control and tendonitis groups. The altered consistency in tendon tissue samples obtained in the present study could be explained initially due to inflammation, with collagen degeneration and necrosis (24-96 h after injury), and due to immature and disorganised collagen fibers at later phases (15-150 days after injury).…”

“…These two techniques were performed under general anaesthesia, and as described by Maia et al (2009), a tenorrhaphy was needed to restore the tendons, complicating the outcomes and enabling the collection of only one fragment per limb. Buck et al (2002) used a biopsy device, similar to that used in this study, to collect flexor tendon fragments. However, the harvested fragments were longer (1.6cm long), the horses outcome after the procedure were not evaluated and the authors did not perform serial collections.…”

“…However, the biopsy must be easy to perform with as little trauma as possible. Buck et al (2002) first described the use of biopsy equipment, allowing for electron microscopy evaluations of tendon fibrils in horses. The study evaluated core biopsies of 12 healthy flexor tendons and 40 flexor tendons at different stages of tendonitis, demonstrating that the typical fibril organisation in the different phases of healing could be shown in the biopsy tissue.…”

Effect of a single injection of autologous conditioned serum (ACS) on tendon healing in equine naturally occurring tendinopathies

“…Tendon biopsies were used because clinical assessment of tendon healing and B-mode ultrasonography alone are limited with regard to sensitivity and reproducibility [ 40 ] and longitudinal needle biopsies were established in human [ 41 , 42 ] and equine surgery [ 29 , 43 ] as minimally invasive and well-tolerated techniques. They allow an insight into tendon architecture as well as the immunohistochemical detection of, for example, collagen type I and III [ 44 ].…”

“…They allow an insight into tendon architecture as well as the immunohistochemical detection of, for example, collagen type I and III [ 44 ]. Disadvantages, however, are the potentially therapeutic, albeit unknown, effect of the biopsy process on tendon healing [ 2 , 45 ], their limited reproducibility and the relatively small volume of tendon tissue harvested [ 29 , 43 ].…”