Objective evaluation for analgesia of the distal interphalangeal joint, the navicular bursa and perineural analgesia in horses with naturally occurring forelimb lameness localised to the foot.
Authors: Katrinaki Vasiliki, Estrada Roberto J, Mählmann Kathrin, Kolokythas Panagiotis, Lischer Christophorus J
Journal: Equine veterinary journal
Summary
# Editorial Summary: Diagnostic Analgesia for Foot Lameness in Horses Distinguishing between distal interphalangeal joint (DIPJ) pain and navicular bursa (NB) pain has proven clinically challenging, prompting this 2023 investigation into the reliability and time-dependent responses of intra-synovial diagnostic blocks. Using objective gait analysis via body-mounted inertial sensors, researchers evaluated 23 horses with naturally occurring forelimb lameness, performing perineural blocks on day one to confirm foot origin, then progressing to DIPJ and NB analgesia on subsequent days with measurements at 2, 5, and 10-minute intervals. The perineural blocks failed to differentiate between DIPJ and NB pain sources, rendering them unreliable for localising pain within the foot; however, NB analgesia produced rapid, stable improvement that persisted throughout the assessment period, whilst DIPJ analgesia demonstrated progressive improvement that continued to change up to 10 minutes post-injection, with significant differences observed between the two techniques at 2 and 5 minutes. For practitioners, these findings suggest that early timing of response (within the first 5 minutes) offers valuable diagnostic information, and practitioners should allow the full 10 minutes before concluding whether a positive response has occurred—particularly important when interpreting equivocal results or planning diagnostic algorithms for foot lameness cases.
Read the full abstract on PubMed
Practical Takeaways
- •When diagnosing foot lameness, perform DIPJ and navicular bursa blocks and evaluate responses at 2 and 5 minutes—early timing is critical for accurate pain localization
- •If lameness improves immediately and consistently after navicular bursa analgesia, suspect navicular bursa pathology; if improvement develops gradually over 10 minutes, suspect DIPJ involvement
- •Perineural nerve blocks alone should not be relied upon to differentiate between DIPJ and navicular bursa pain—proceed to intra-synovial analgesia for definitive localization
Key Findings
- •Perineural analgesia is not reliable for differentiating pain origin between DIPJ and navicular bursa
- •DIPJ analgesia showed significant improvement differences at 2 min (p<0.001) and 5 min (p=0.04) compared to navicular bursa analgesia
- •Navicular bursa analgesia produced stable, high-degree improvement over time, while DIPJ analgesia improved variably up to 10 minutes
- •Early evaluation (2-5 min) of DIPJ and navicular bursa analgesia can reliably determine pain origin in foot lameness