Noninfected tenosynovitis of the digital flexor tendon sheath: a retrospective analysis of 76 cases

Abstract

Until recently, the pathogenesis of noninfected tenosynovitis of the digital flexor tendon sheath (DFTS) has been considered obscure. With the advent of tenoscopy some inciting causes have been described, but to date few cases with a precise diagnosis have been reported. Tenoscopic surgery enables accurate diagnosis and facilitates treatment of noninfected tenosynovitis of the DFTS. The case records of all horses with noninfected tenosynovitis of the DFTS admitted to a referral clinic over a 7-year period were evaluated retrospectively. Follow-up information was obtained by telephone questionnaire. A total of 76 horses were referred; all were evaluated tenoscopically and 11 of these subsequently were explored by open surgical techniques. The most common diagnoses were marginal tears of the deep digital flexor tendon (DDFT) (n = 44) and tears of the manica flexoria (MF) (n = 23). Greater than 6 months' follow-up information was available for 61 animals, of which 68% were sound and 54% returned to preoperative levels of performance. Sheath distension was eliminated in 33% and improved in 69% of horses. Marginal tears of the DDFT, marked preoperative distension and open surgical repair of deep digital flexor lesions were associated with reduced levels of post operative performance: Marginal tears were associated with post operative lameness and long tears with a reduced performance level compared with short tears. Marginal tears of the deep digital flexor tendon, marked preoperative distension and increasing duration of clinical signs also were associated with lack of improvement in distension following surgery. Tenosynovitis of the DFTS may result from tears in the deep or superficial digital flexor tendons, manica flexoria or other structures with synovial communication. To date, these can be identified confidently only by tenoscopy, which also permits appropriate lesion management. The diagnostic information obtained from and therapeutic options offered by tenoscopy justify its early use in cases of noninfected tenosynovitis of the DFTS.