An optimised injection technique for the navicular bursa that avoids the deep digital flexor tendon

Area of Science:

• Veterinary Medicine
• Equine Surgery
• Diagnostic Imaging

Background:

• Traditional palmar navicular bursa injections risk deep digital flexor tendon (DDFT) puncture.
• Developing alternative techniques is crucial for equine limb health and treatment efficacy.

Purpose of the Study:

• To introduce and evaluate a novel radiographic-guided lateral approach for navicular bursa injection.
• To assess the technique's ability to avoid DDFT penetration.
• To determine the risk of synovial and soft tissue penetration during the procedure.

Main Methods:

• Prospective study involving cadaver limbs and clinical cases.
• Radiographic and magnetic resonance imaging (MRI) were used to assess needle placement.
• Injections were performed with and without synovial distension of adjacent structures (DIP joint, DFTS).

Main Results:

• The lateral injection technique successfully achieved navicular bursal injection in all 71 limbs.
• Distension of the distal interphalangeal (DIP) joint significantly increased the risk of joint puncture (19x).
• Distension of the digital flexor tendon sheath (DFTS) also elevated the risk of sheath puncture (2.7x).

Conclusions:

• The lateral approach effectively avoids DDFT puncture during navicular bursa injections.
• Clinicians must consider the increased risk of synovial penetration into the DIP joint or DFTS when these structures are potentially infected.
• This technique offers a safer alternative for navicular bursa injections in equine practice.