Radiofrequency Probe and Sharp Transection for Tenoscopic-Guided Desmotomy of the Accessory Ligament of the Superficial Digital Flexor Tendon

Vascularity evaluation of the equine tarsocrural and proximal intertarsal joint septum, and comparative analysis of two arthroscopic transection techniques

OBJECTIVE

To evaluate vascularity of the synovial membrane covered septum (SMS) separating the tarsocrural (TC) and proximal intertarsal (PIT) joints (Part 1) and compare two methods of transection, electrosurgical or Ferris Smith rongeur (FS rongeur) (Part 2).

STUDY DESIGN

Experimental study.

SAMPLE POPULATION

Part 1, 10 SMS (n = 5 horses). Part 2, six horses (n = 12 tarsi).

METHODS

In part 1, SMS harvested postmortem were each divided into eight regions of interest (ROIs), processed for histology, and immunostained with anti-α-actin antibody for blood vessel identification. Vascular density was calculated for each ROI. Data was compared within and between horses. In part 2, six horses underwent TC arthroscopy. Each limb was randomly assigned to undergo either electrosurgical or FS rongeur SMS transection. SMS transection and total operative time were recorded. Intraoperative hemorrhage was scored. Data was compared between both techniques.

RESULTS

Significant interindividual variations in SMS vascular density were detected (p = .02), but there were no differences among ROIs. No differences in the transection time were detected between electrosurgery (4.83 ± 0.54 min) and FS rongeur (4.33 ± 0.67 min). No differences were found in intraoperative hemorrhage scores between techniques.

CONCLUSION

Vascularity within the SMS varies among horses but not within its regions. Electrosurgical or FS rongeur transection of the medial SMS during tarsocrural arthroscopy is a rapid technique and improves surgical access to the dorsal compartment of the PIT.

Large animal models for the study of tendinopathy

Tendinopathy has a high incidence in athletes and the aging population. It can cause pain and movement disorders, and is one of the most difficult problems in orthopedics. Animal models of tendinopathy provide potentially efficient and effective means to develop understanding of human tendinopathy and its underlying pathological mechanisms and treatments. The selection of preclinical models is essential to ensure the successful translation of effective and innovative treatments into clinical practice. Large animals can be used in both micro- and macro-level research owing to their similarity to humans in size, structure, and function. This article reviews the application of large animal models in tendinopathy regarding injuries to four tendons: rotator cuff, patellar ligament, Achilles tendon, and flexor tendon. The advantages and disadvantages of studying tendinopathy with large animal models are summarized. It is hoped that, with further development of animal models of tendinopathy, new strategies for the prevention and treatment of tendinopathy in humans will be developed.

Quantifying the magnitude of local tendon injury from electrosurgical transection

BACKGROUND

Electrocautery is a common surgical technique and is often used during shoulder arthroplasty to elevate or transect the subscapularis tendon. The relative amount of tissue damage caused by cautery as opposed to sharp transection is not currently known. The purpose of this study was to examine local tissue damage resulting from electrocautery vs. sharp transection with a scalpel. We hypothesized that the electrosurgical unit would cause higher collateral tissue damage and cell death compared with sharp transection.

METHODS

Twelve cadaveric ovine shoulders were randomized to either the electrosurgical or sharp transection group. The infraspinatus tendon was isolated, and a partial-thickness transection was made using either a monopolar electrosurgical device (Bovie) or No. 10 scalpel blade. Tendon explants were then visualized with confocal microscopy to evaluate tissue architecture. A live/dead assay was performed using microscopy imaging analysis software. Comparisons between Bovie and scalpel transection were made using the Mann-Whitney U test, and the cell death percentage at standardized distances from the transection site was compared between groups using a mixed-model analysis. Significance was defined at P < .05.

RESULTS

The cellular and tendon fibril architecture was well maintained beyond the scalpel transection site, whereas Bovie transection disrupted the architecture beyond its transection path. The percentage of dead cells in the Bovie group (74.9% ± 31.2%) was significantly higher than that in the scalpel group (27.6% ± 29.9%, P = .0004). Compared with the transection site, the cell death percentage after Bovie transection significantly declined at 2.5 mm whereas that after scalpel transection significantly declined at 1 mm from the transection site.

CONCLUSION

There was a significantly higher dead cell percentage in the Bovie transection group, indicating extensive damage beyond the local incision site, compared with sharp transection. Electrosurgical transection of the ovine infraspinatus tendon ex vivo caused higher cell death and greater tissue architecture disruption compared with sharp scalpel transection.

Diagnostic tenoscopy of the carpal sheath with a needle arthroscope in standing sedated horses

OBJECTIVE

To investigate the use of a needle arthroscope for diagnostic tenoscopy of the carpal sheath in standing horses.

STUDY DESIGN

Experimental study.

SAMPLE POPULATION

Six forelimbs for the cadaveric part of the study and six horses for the in vivo part of the study.

METHODS

Six cadaveric limbs were used to perform carpal sheath tenoscopy with a 1.2-mm-diameter needle arthroscope (65 and 100 mm long), followed by tenoscopy with a 4-mm arthroscope through a standard proximolateral approach. Then, unilateral standing carpal sheath tenoscopy was performed in six healthy sedated horses with a 65-mm-long needle arthroscope. Limbs were maintained in flexion during the procedure by using a custom-made splint and base. Degree of tenoscopic evaluation, safety, horse tolerance, and complications were recorded.

RESULTS

Visibility at the most distal aspect of the sheath was absent for the needle arthroscopes vs a standard arthroscope. The maneuverability with a 65-mm needle arthroscope was excellent and allowed exhaustive visualization of the proximal region of the carpal sheath in cadaveric limbs and standing horses (six of six). However, visualization of the intertendinous recess was partial in most horses (four of six) vs cadavers (complete in six of six) because of remaining flexor tendon tension in standing horses. No major complications were encountered.

CONCLUSION

Standing carpal sheath tenoscopy allowed a safe and thorough evaluation of most structures in the proximal region of the sheath and offers an alternative diagnostic technique.

CLINICAL SIGNIFICANCE

Horses with unrewarding results after traditional imaging or that require an accurate diagnosis before treatment may benefit from this alternative procedure.