A novel ultrasonographic assisted technique for desmotomy of the palmar/plantar annular ligament in horses.
Authors: Espinosa Pablo, Nieto Jorge E, Snyder Jack R, Galuppo Larry D, Katzman Scott A
Journal: Veterinary surgery : VS
Summary
# Editorial Summary Palmar/plantar annular ligament (PAL) desmotomy is an established surgical intervention for horses with digital flexor tendon sheath pathology, yet traditional blind or palpation-guided approaches carry risks of iatrogenic damage to the underlying tendons and neurovascular structures. Espinosa and colleagues developed and evaluated an ultrasound-assisted desmotomy (UAD-PAL) technique using a custom-designed hook knife, testing it across cadaveric limbs (n=22) and live horses (n=6, including two clinical cases) to assess efficacy and complication rates. Complete PAL transection was achieved in 20 of 22 limbs (91%), with no iatrogenic injury to flexor tendons, synovial sheaths, or neurovascular structures identified in any case; the instrument achieved correct positioning on the first attempt in 19 of 22 cases (86%), though subcutaneous misplacement occurred twice and one thickened PAL (3 mm) resisted complete division. The procedure's advantages lie in its real-time ultrasonic visualisation of ligament anatomy and precise instrument placement, feasibility under standing sedation, and superior safety profile compared to blind techniques—making it particularly valuable for routine cases, though practitioners should consider alternative approaches when confronted with significantly thickened ligaments. For equine surgeons and referring veterinarians managing flexor tendon conditions, this technique represents a meaningful refinement in precision and safety, though widespread adoption will depend on access to appropriate instrumentation and operator training in ultrasound-guided surgical methods.
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Practical Takeaways
- •This ultrasound-guided technique offers a reliable, minimally invasive alternative to traditional desmotomy with a 91% success rate and no reported soft tissue complications in the digital flexor tendon sheath
- •Standing sedation with distal limb splinting eliminates general anesthesia risks, improving safety and reducing cost for routine PAL desmotomy cases
- •Pre-operative ultrasound assessment of PAL thickness is recommended—consider alternative techniques if PAL measures ≥3 mm to ensure complete ligament transection
Key Findings
- •Complete transection of the palmar/plantar annular ligament was achieved in 20/22 limbs (91%) using ultrasound-assisted desmotomy with a custom hook knife
- •No iatrogenic damage to adjacent structures (flexor tendons, sheaths) occurred in any of the 22 cases
- •The procedure was successfully performed in standing sedated horses using a distal limb splint, eliminating need for general anesthesia
- •Thickened PAL (≥3 mm) was associated with failed complete transection and may require alternative surgical approaches