An ultrasound-guided, tendon-sparing, lateral approach to injection of the navicular bursa.
Authors: Nottrott K, De Guio C, Khairoun A, Schramme M
Journal: Equine veterinary journal
Summary
# Editorial Summary: Ultrasound-Guided Lateral Navicular Bursa Injection Navicular disease frequently requires intra-bursal medication, yet traditional injection techniques risk iatrogenic deep digital flexor tendon (DDFT) damage and expose clinicians to radiation during fluoroscopic guidance. Nottrott and colleagues evaluated a lateral, ultrasound-guided approach to navicular bursocentesis in 62 cadaveric and 26 live equine forelimbs, depositing contrast medium under real-time ultrasound visualisation with the foot positioned in flexion. Successfully achieving bursa-only injection in 78% of attempts (89 of 114 limbs), with an overall success rate of 91%, the technique proved both effective and safe—cadaveric dissection confirmed zero instances of DDFT penetration, whilst avoiding the radiation burden of conventional radiographic-guided procedures. Aberrant injections occurred in 10 limbs (9%), primarily into the distal interphalangeal joint or peribursal tissues, correlating significantly with poor ultrasound image quality. Whilst this lateral approach represents a practical advancement for practitioners treating navicular pathology, clinicians should note that efficacy was demonstrated in sound horses without naturally occurring disease, so outcomes in clinically affected animals may differ, and the behaviour of therapeutic agents may not precisely mirror that of the contrast medium used in this study.
Read the full abstract on PubMed
Practical Takeaways
- •This lateral ultrasound-guided technique offers a safe, effective alternative to traditional navicular bursa injection without requiring radiographic guidance or risking deep digital flexor tendon penetration
- •Success depends heavily on image quality—adequate ultrasound visualization is critical; poor images significantly increase risk of off-target injection
- •Practitioners should recognize that bursa entry is confirmed by synovial fluid appearance at the needle hub, making real-time ultrasound feedback valuable for clinical application
Key Findings
- •Ultrasound-guided lateral navicular bursa injection successfully deposited contrast in 91% of limbs (104/114) with 78% achieving bursa-only deposition (89/114)
- •Dissection of cadaveric limbs showed no penetration of the deep digital flexor tendon using this lateral approach
- •Failure to inject the navicular bursa was significantly associated with poor ultrasound image quality (P=0.04) and resulted in aberrant injections to the DIP joint (4%), peribursal tissues (4%), or flexor tendon sheath (0.9%)
- •Synovial fluid was observed at the needle hub in 58% of live horses, confirming bursa access