Injuries to the superficial digital flexor tendon branches: Clinical presentation, diagnostic features and outcome

Spiesshofer, P; O'Hara, V; Garrett, KS; Smith, RK

Abstract

BackgroundInjury of the superficial digital flexor tendon (SDFT) branch is uncommon and the response to different treatments has not been reported.ObjectivesThe aim of this study was to describe the clinical presentation, diagnostic features, treatment methods, and outcome of horses diagnosed with SDFT branch injuries. We hypothesised that the application of ancillary treatments would improve outcome and reduce re-injury rate. We further hypothesised that SDFT branch injuries associated with avulsion fractures would have a decreased probability of return to racing.Study DesignRetrospective case series.MethodsData from medical records of horses diagnosed with SDFT branch injuries over a 10-year period (2014-2024) were reviewed. The inclusion criterion was the diagnosis of non-septic overstrain tendonitis of the SDFT branch based on ultrasonographic evaluation. Outcomes (return to racing, re-injury, and earnings) were compared with diagnostic features and treatment modalities for Thoroughbred racehorses.ResultsTwenty-one Thoroughbreds and nine other breeds were included in the descriptive data. Lesions in the forelimb were overrepresented (n = 25, hindlimb n = 7). There was an even split between the laterality of the affected branches (medial and lateral). Of the Thoroughbred racehorses that had raced prior to injury, 7/13 (53.8%) returned to racing. Overall, 9/20 (45%) surviving horses raced post-injury. No treatment group was significantly associated with a higher probability of return to racing compared to conservative management alone. The presence of avulsion fractures did not adversely affect the return to racing statistically (p = 0.84). The re-injury rate was 19%.Main LimitationsSmall size of treatment groups with heterogeneous treatment regimens and lack of a standardised rehabilitation programme.ConclusionsOf the Thoroughbred racehorses with SDFT branch injuries, 45% returned to racing. The presence of avulsion fractures did not decrease the likelihood of return to racing. Ancillary treatments did not influence the overall outcome, although the statistical power was limited.

Citation

Spiesshofer, P., O'Hara, V., Garrett, K., & Smith, R. (2025). Injuries to the superficial digital flexor tendon branches: Clinical presentation, diagnostic features and outcome. Equine Veterinary Education, https://doi.org/10.1111/eve.14205

• Journal Article Type: Article
• Acceptance Date: Jun 24, 2025
• Online Publication Date: Jul 18, 2025
• Publication Date: 2025
• Deposit Date: Jul 29, 2025
• Publicly Available Date: Jul 29, 2025
• Print ISSN: 0957-7734
• Electronic ISSN: 2042-3292
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• DOI: https://doi.org/10.1111/eve.14205
• Keywords: horse; avulsion; stem cells; superficial digital flexor tendon branch; tendon injury; MESENCHYMAL STEM-CELLS; SESAMOID FRACTURE FRAGMENTS; ARTHROSCOPIC REMOVAL; RACING PERFORMANCE; TENDINITIS; HORSES; TENDINOPATHY; RACEHORSES; MANAGEMENT; INJECTION