Four-step tenoscopic technique to resect a torn proximal manica flexoria while sparing the mesotendons of the deep digital flexor tendon in 30 horses.

Overview

• This research article describes a refined surgical technique using a two-portal tenoscopic approach to remove a torn proximal manica flexoria (MF) in horses.
• The technique aims to preserve the mesotendons (MTs) of the deep digital flexor tendon (DDFT), which are important for maintaining blood flow and tendon health.

Background and Purpose

• The proximal manica flexoria is a structure located at the level of flexor tendons in horses, and tears in this area can cause lameness and impair function.
• Traditional procedures to resect the MF may damage mesotendons, risking compromised blood supply to the deep digital flexor tendon.
• The purpose of this study was to develop and describe a less invasive, four-step tenoscopic technique that spares the mesotendons while effectively removing the torn MF tissue.
• Maintaining the extrinsic blood supply through preservation of mesotendons is thought to improve post-surgical healing and function.

Methods

• The study was prospective, involving 30 client-owned horses diagnosed with proximal MF tears.
• The surgical technique used two portals (small incisions for endoscopic tools) for tenoscopic access to the tendon area.
• MF resection was performed in four distinct steps:
• Step 1: Cut the lateral attachment of the MF to the superficial digital flexor tendon (SDFT), carefully avoiding the lateral mesotendon.
• Step 2: Transect the medial attachment of the MF to the SDFT distally to proximally until reaching the medial mesotendon, again preserving the MT.
• Step 3: Cut the proximal medial attachment of the MF dorsal to the deep digital flexor tendon (DDFT).
• Step 4: Apply a Kocher-Ochsner clamp, rotate to disrupt connective tissue, and extract the MF.
• Postoperative monitoring included telephone interviews at least six months after surgery to evaluate long-term outcomes.

Results

• Tears were located medially in 66.7% of horses, laterally in 23.3%, and on both sides in 10%.
• The majority (90%) of affected limbs were hindlimbs, with forelimb cases making up 10%.
• Of 11 sport horses treated, 81.8% returned to their previous or higher work level.
• Among 17 leisure horses, 70.6% reached the same or improved status post-surgery.
• The MF was successfully resected in all 30 horses regardless of tear location, indicating the reproducibility and effectiveness of the technique.

Conclusions

• The four-step two-portal tenoscopic technique allows complete resection of the proximal MF while sparing the mesotendons of the DDFT.
• Preserving the mesotendons is crucial for maintaining tendon vascularization, reducing surgical trauma, and potentially enhancing recovery.
• The technique’s detailed stepwise description supports reproducibility by surgeons.
• The positive long-term outcomes, with many horses returning to previous levels of performance, support the clinical value of this surgical approach.
• Overall, this method represents an advancement in minimally invasive tendon surgery in horses by balancing thorough removal of pathological tissue with preservation of healthy tendon structures.