Superficial Digital Flexor Tenonitis* Is There Still a Role for Surgery?

Is there still a role for surgery? Yes, surgical management continues to play an important role in the management of all horses with injuries to the superficial digital flexor tendon (SDFT), in both racehorses and sports horses. Intralesional therapy has certainly progressed and there are numerous options for augmenting repair of damaged SDFT. Regenerative therapy continues to improve and with additional experience healing of SDFT using this approach will likely play an important role in management, singularly or in combination with other forms of management, including surgery. The BEST approach is likely the use of combination therapy, including an intralesional option (injection or surgery, or both), a surgical procedure (superior check desmotomy [SCD] alone or in addition to other surgical procedures), rigorously controlled post-injury exercise (see below, without turn out exercise), and careful monitoring of tendon health when the horse returns to training/performance. Surgical management of horses with SDF tendonitis/tendonopathy satisfies many of the time-honored principles used in tendon healing. Superior check desmotomy increases the bone-ligament-tendon-bone interface length, which protects the healed tendon likely harboring an inelastic scar from incomplete or inadequate repair. While regenerative approaches are being used and continuously refined I am not convinced healing is occurring without scar tissue formation, given recurrence of injury in many horses undergoing this therapeutic option. Carpal retinaculotomy (incising the carpal retinaculum, both outer and inner lamina, in horses with proximally located SDFT lesions), annular desmotomy (AD, severing the annular ligament in the distal metacarpal/palmar fetlock regions), and metacarpal fasciotomy (severing the dense metacarpal fascia in the region of SDFT enlargement) all improve gliding function, a time-honored theorem used to manage all tendon injuries.