Endoscopically Assisted Annular Ligament Release in Horses

Abstract

An endoscopically assisted technique for internally dividing the palmar or plantar annular ligament was developed in six cadaver limb specimens and two anesthetized horses. Under arthroscopic view, a slotted cannula was inserted into the digital sheath through a stab wound proximal to the annular ligament and advanced through the fetlock canal superficial to the flexor tendons with the slot oriented toward the fibers of the annular ligament. Division of the annular ligament by 90-degree tipped open and guarded blades was observed and verified by direct arthroscopic view. At necropsy, complete division of the annular ligament without iatrogenic damage to the neurovascular structures was confirmed by dissection. Annular ligament division was performed in seven horses with complex tenosynovitis conditions. Tenoscopic examination and removal of tendon and digital sheath adhesions, masses, and bands was followed by endoscopically assisted annular ligament transection. At follow-up, five horses were sound athletes without recurrent digital sheath problems, one horse had residual lameness, and one horse was still convalescing.

Palmar annular ligament desmotomy in horses with the Arthrex-Centerline™ : An <i>ex-vivo</i> study

“…With the blind technique, the surgeon cannot be sure whether the manica flexoria has been accidentally incised during surgery. The tenoscopy definitely offers the advantage of better visualization within the operative field, a better diagnosis and a reduction in both the surgical wound and risks of complications (Nixon et al, 1993;Barr et al, 1995;Dik et al, 1995;Wright and McMahon, 1999). Since the advent of tenoscopy, reported cases of tendon fistulas and post-operative infections compared to those reported in the use of the open technique are definitely less frequent (Gerring and Webbon, 1984;Wright and McMahon, 1999).…”

“…Since the advent of tenoscopy, reported cases of tendon fistulas and post-operative infections compared to those reported in the use of the open technique are definitely less frequent (Gerring and Webbon, 1984;Wright and McMahon, 1999). Another method of the PAL desmotomy consists of the use of a slotted cannula and a scalpel blade rotated 90° (Nixon et al, 1993). The advantage of using a slotted cannula includes full control with visualization of the PAL during resection.…”

“…Ten horse distal limbs from horses free of PAL disease were prepared for tenoscopy of the digital flexor tendon sheath (DFTS). Five of these specimens were randomly assigned to Group A, in which a tenoscopic approach with a dual port was performed as previously described (Nixon et al, 1993). The optical port was open on the side of the distal portion of the digital flexor tendon sheath with a view of 30° and a 4.0-mm diameter.…”

“…Continuous distension of the DFTS has been achieved with an arthroscopy pump with a pressure of 100 mmHg and a flow rate of 40 ml/min. After exploring the tendon sheath and identifying the annular ligament, a portal was created with the instrument in the proximal portion of the tendon sheath as described (Nixon et al, 1993). For desmotomy of the PAL, a hook knife was used.…”

“…The PAL desmotomy has been described with several techniques, such as surgical treatment for PAL syndrome. Open surgery, minimally blinded surgery and endoscopic surgery have been employed (Nixon, 1990;Nixon et al, 1993;Fortier et al, 1999;Hawkins and Moulton, 2002;Smith and Wright, 2006). The use of endoscopic techniques are minimally invasive and allow access to the PAL, creating intraoperative visualization of the intrathechal structures.…”