Needle tenoscopy of the digital flexor tendon sheath in a standing equine cadaver model using a novel approach and guided palmar/plantar annular ligament desmotomy.

Objective: (1) To evaluate the feasibility of needle tenoscopy of the digital flexor tendon sheath (DFTS) using basisesamoid (BS) and proximolateral (PL) approaches in a standing equine cadaver model. (2) To report visualization of intrathecal DFTS anatomy via both approaches. (3) To determine the efficacy of needle scope-guided palmar/plantar annular ligament (PAL) desmotomy. (4) To report any iatrogenic damage associated with the procedure.

Study design: Ex vivo experimental.

Sample population: Ten equine cadaver limbs.

Methods: Limbs were placed in a Kimzey leg-saver splint and needle tenoscopy was performed using the BS and PL approaches. Two European College of Veterinary Surgeons (ECVS) Diplomates assessed and categorized intrathecal site visualization as poor, partial, or excellent. Needle scope-guided PAL desmotomy was performed after DFTS exploratory needle tenoscopy. Limbs were dissected and examined for the presence of iatrogenic damage and completeness of PAL desmotomy. A Wilcoxon signed-rank test was used to compare visualization scores for both approaches.

Results: Needle tenoscopy of the DFTS in a standing model was feasible from both BS and PL approaches. Excellent visualization of clinically significant intrathecal anatomy within the fetlock canal was achieved from both approaches (p ≤ .001), with minimal iatrogenic damage. The PL approach allowed more structures to be visualized than the BS approach (p = .025). All PAL desmotomies were completed without associated iatrogenic damage.

Conclusion: Needle tenoscopy of the DFTS in a standing model provided excellent visualization of intrathecal sites within the fetlock canal. It facilitated complete PAL desmotomy.

Clinical significance: Needle ten0oscopy can be used to assess the DFTS and to guide PAL desmotomy in a standing horse.