Ex vivo evaluation of a percutaneous thread‐transecting technique for desmotomy of normal palmar/plantar annular ligaments in horses

Abstract

To develop and describe a minimally invasive, ultrasound-guided, percutaneous technique for the desmotomy of equine palmar/plantar annular ligaments (PALs) using a transecting thread. Study design: Ex vivo study.Sample population: Twenty-one normal equine distal limb specimens. Methods: Under ultrasonographic guidance, a surgical thread was percutaneously placed around the PAL through 2 skin punctures (proximal and distal) using a 18 gauge spinal needle in equine limbs (11 forelimbs, 10 hindlimbs) with normal PALs. The ligament was transected by a back-and-forth motion of the thread until the loop emerged from the proximal skin puncture site. Each specimen was dissected and assessed for completeness of transection and iatrogenic damage under direct visualization. Descriptive statistics were reported. Results: The PAL was completely transected in 17/21 limbs. The mean duration of the procedure was 16 minutes. Superficial needle puncture or subtle abrasion of the superficial digital flexor tendon was noticed in 4 limbs. No iatrogenic injury to other intrathecal structures was identified. After PAL division, the needle entry and exit points had a mean diameter of 1.2 and 1 mm, respectively. Conclusion: Desmotomy of normal PALs in equine limb specimens was performed effectively using the percutaneous thread-transecting technique with minimal iatrogenic damage to adjacent structures.

Minimally invasive ultrasound‐assisted cutting thread tenotomy of the deep digital flexor tendon in horses: An ex vivo study

“…[14][15][16][17][18] In contrast, a recent study in horses revealed that the annular ligament was not completely severed in 4/21 horses. 19 Failures were attributed to technique errors or the difficulty of imaging the thin annular ligament properly during the procedure. The DDFT can be identified easily with ultrasound and our results confirmed that verification of needle positioning with ultrasound is effective in ensuring that the thread is looped around the DDFT.…”

“…In this study, a 20 gauge needle was used instead of the 18 gauge needle commonly utilized in other transecting thread studies. [17][18][19] However, an 18 gauge needle is stiffer and may be required in vivo if tendon tension causes the 20 gauge needle to lose the bend required to go around the DDFT. In such a case, hydrodissection would be once again a critical step to add to prevent neurovascular puncture.…”

“…Iatrogenic SDFT damage was seen in our study and also in another equine study where four minor abrasions were reported during annular ligament desmotomy with a cutting thread. 19 Despite SDFT injuries being undesirable, we considered these injuries to be minimal and probably of no clinical consequence, especially if performing the technique in a laminitic horse where the goal is to allow pasture soundness. Due to the nature of the technique, tendon punctures or peripheral transection of small fiber bundles may still occur on the SDFT.…”

“…15,18 Based on this information, a cutting thread technique has been applied for annular ligament desmotomy in horses and it could also be applied for DDFT tenotomy. 19 The purpose of this study was to evaluate the feasibility and limitations associated with a minimally invasive, percutaneous ultrasound-assisted cutting thread technique for tenotomy of the deep digital flexor tendon (DDFT) in horses. It was hypothesized that the technique would allow quick and complete transection of the DDFT through incisions smaller than required for the traditional method.…”

Ex‐vivo evaluation of a percutaneous looped thread desmotomy of the accessory ligament of the deep digital flexor tendon in horses

“…23 This procedure was successfully adapted to a percutaneous thread-transecting technique for desmotomy of normal palmar/plantar annular ligaments (PAL) in cadaveric equine specimens. 24 One of the authors (CMK) tested different suture materials to perform a similar technique and concluded that FiberWire can successfully transect the PAL (unpublished data).…”