ENDOSCOPICALLY ASSISTED ANNULAR LIGAMENT RELEASE IN HORSES

An endoscopically assisted technique for internally dividing the palma r or plantar annular ligament was developed in six cadaver limb specim ens and two anesthetized horses. Under arthroscopic view, a slotted ca nnula was inserted into the digital sheath through a stab wound proxim al to the annular ligament and advanced through the fetlock canal supe rficial to the flexor tendons with the slot oriented toward the fibers of the annular ligament. Division of the annular ligament by 90-degre e tipped open and guarded blades was observed and verified by direct a rthroscopic view. At necropsy, complete division of the annular ligame nt without iatrogenic damage to the neurovascular structures was confi rmed by dissection. Annular ligament division was performed in seven h orses with complex tenosynovitis conditions. Tenoscopic examination an d removal of tendon and digital sheath adhesions, masses, and bands wa s 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 st ill convalescing.