Tenoscopic examination and proximal annular ligament desmotomy for treatment of equine "Complex" digital sheath tenosynovitis

Objective-To determine the outcome of horses with "complex" digital tenosyn ovitis treated by tenoscopic proximal annular ligament desmotomy and resect ion of synovial masses or adhesions, or both, within the digital sheath. Study Design-Retrospective evaluation. Animals or Sample Population-Twenty-five horses with a clinical and ultraso nographic diagnosis of palmar or plantar proximal annular ligament constric tion and ultrasonographic evidence of synovial masses or adhesions within t he digital tendon sheath. Methods-Each horse had tenoscopic surgery for annular ligament desmotomy co mbined with adhesiolysis and/or synovial mass resection. Mean follow-up tim e was 3.4 years. Spearman's rank correlation was used to assess the relatio nship between functional outcome or cosmetic results and preoperative varia bles including duration of clinical signs, digital sheath synovial fluid to tal protein concentration and nucleated cell count, thickness of the palmar or plantar proximal annular ligament (PAL), severity of adhesions, severit y of synovial masses, degree of synovial distention, or limb affected. Results-A total of 18 (72%) horses returned to athletic soundness, 4 were i mproved but not sound, and 3 were not improved. Cosmetic outcome was normal in 10 horses, improved but not normal in 12, and not improved in 3 horses. Cosmetic and functional outcome were significantly adversely affected by t he duration of clinical signs and the severity of synovial masses. Conclusions-With appropriate tenoscopic surgical attention, horses with com plex tenosynovitis syndrome characterized by synovial masses, adhesions, or both adhesions and masses, and PAL constriction, have a good prognosis for return to athletic soundness. Clinical Relevance-Horses with PAL constriction and additional digital tend on sheath pathology such as adhesions and synovial masses have a 72% chance of returning to sound athletic performance, however 60% of horses retain s ome degree of cosmetic blemish in the affected limb. There is an inverse re lationship between the duration of clinical signs and outcome, and therefor e, prompt surgical attention is advised. (C) Copyright 1999 by The American College of Veterinary Surgeons.