Electrosurgical tenoscopic desmotomy of the accessory ligament of the superficial digital flexor muscle (proximal check ligament) in horses.

Objective: To report a tenoscopic technique using monopolar electrosurgery to transect the accessory ligament of superficial digital flexor muscle (AL-SDFM) and outcome in 33 horses.

Study Design: Case series.

Animals: Horses (n=33).

Methods: Medical files and surgery video recordings of horses that had AL-SDFM desmotomy performed by tenoscopy with monopolar electrosurgical electrodes were reviewed.

Results: Of 33 horses, 24 were Standardbred racehorses with surgery performed bilaterally for superficial digital flexor tendonitis and 9 horses had flexural deformity. Severe (n=6) and mild (6) intrathecal hemorrhage was the most common intraoperative complication. Large intrathecal vessels including the nutrient artery were successfully electrocoagulated and AL-SDFM transection was completed. Clear/serosanguinous drainage from skin incisions was observed for 4.3±3.3 days (mean, SD). Protracted wound drainage for >4 days occurred in 10 horses, principally in the group treated for flexural deformities (P=.01).

Conclusions: Sixty-four AL-SDFM were transected under tenoscopic observation using monopolar electrodes. Electrocoagulation of large intrathecal vessels, including the nutrient artery, was possible in all cases and allowed completion of desmotomy. Postoperative wound care was similar to routine tenoscopy in most (70%) horses. Aseptic protracted wound drainage was observed in 30% of horses (principally those with flexural deformity), and led to a prolonged hospitalization.