Effect of single and double hemitenotomy on equine deep digital flexor tendon length and strength in experimental load challenges.
Authors: Zetterström Sandra M, Boone Lindsey H, Farag Ramsis, Weimar Wendy H, Caldwell Fred J
Journal: Veterinary surgery : VS
Summary
# Editorial Summary: Double Hemitenotomy as an Alternative to Complete Deep Digital Flexor Tenotomy Surgical tenotomy of the deep digital flexor tendon remains a consideration in managing severe laminitis, but complete division carries risks of complications including tendon rupture and altered biomechanics. Zetterström and colleagues investigated whether a double hemitenotomy technique—two partial cuts through the tendon rather than complete division—could achieve similar mechanical benefits with potentially better preservation of tendon integrity. Using both isolated tendons and cadaveric forelimbs subjected to tensile and compressive loading, the researchers compared single hemitenotomy, double hemitenotomy, and complete tenotomy, measuring tendon lengthening, load-bearing capacity, and failure thresholds. The double hemitenotomy produced meaningful lengthening (1.9–3.05 mm in different test conditions) and load reduction (11.2–16.7 kg) comparable to complete tenotomy, suggesting equivalent mechanical relief of tension on compromised laminae. Notably, the first hemitenotomy incision produced less load reduction than the second, indicating cumulative mechanical effect. Whilst double hemitenotomy did reduce the tendon's tensile strength, the load at failure (195 kg) remained similar to or exceeded estimates of normal digital flexor tendon loading during stance, implying the tendon retained adequate safety margins for weight-bearing. For farriers and veterinarians managing chronic laminitis cases, this research suggests double hemitenotomy warrants further investigation as a potentially less destructive alternative to complete tenotomy, though the authors appropriately emphasise that in vivo validation is essential before clinical adoption.
Read the full abstract on PubMed
Practical Takeaways
- •DHT may offer a middle-ground surgical option for laminitis cases, achieving load reduction comparable to complete tenotomy while preserving more tendon strength
- •Residual strength after DHT (195 kg failure load) appears adequate for normal stance loads, potentially reducing post-operative complications
- •These ex vivo results are promising but require in vivo validation before widespread clinical adoption—discuss with your veterinarian whether DHT might be appropriate for your horse
Key Findings
- •Double hemitenotomy (DHT) lengthened isolated DDFTs by 1.9 mm and cadaveric forelimbs by 3.05 mm with load reductions of 16.7 kg and 11.2 kg respectively
- •DHT achieved less lengthening than complete tenotomy (CT) but produced comparable load reduction during compressive testing
- •Double hemitenotomy tendons failed at 195 kg tensile load, which exceeds estimated DDFT load at stance, suggesting maintained functional strength
- •Load reduction from first hemitenotomy incision was significantly smaller than the second incision (P=0.022)