Desmitis of the palmar or plantar ligaments of the proximal interphalangeal joint: A descriptive case series.
Authors: Peeters Manon W J, Ott Stephan, van Veggel Elisabeth, Berner Dagmar, Perrier Melanie
Journal: Equine veterinary journal
Summary
# Editorial Summary: Palmar/Plantar Ligament Injuries at the PIP Joint Desmitis of the palmar and plantar ligaments supporting the proximal interphalangeal joint (PIP) has received minimal attention in equine literature, yet may represent a clinically significant source of lameness. Researchers retrospectively analysed MR images from 29 lame horses across three institutions, evaluating the visibility and pathological changes of four distinct ligamentous structures (axial and abaxial palmar/plantar ligaments, and their respective digital annular ligament attachments) using low-field MR imaging. Whilst PIP ligament desmitis was the primary MR finding in 45% of cases, significant diagnostic challenges emerged: the abaxial ligaments proved distinctly visible in only 5% of examinations, making structural differentiation unreliable in clinical practice. Periligamentous oedema accompanied 74% of abaxial ligament lesions, and approximately one-third of affected ligaments showed enthesophyte formation. For practitioners, this work confirms that PIP ligament pathology warrants consideration in lameness investigations—particularly where clinical signs localise to this region—though sonographic or MR interpretation requires careful correlation with clinical findings given the imaging limitations. The high prevalence of periligamentous oedema associated with abaxial ligament desmitis offers a useful diagnostic indicator, but the difficulty in differentiating individual structures underscores the importance of comprehensive imaging protocols and specialist interpretation rather than relying on MR findings alone.
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Practical Takeaways
- •PL-PIPJ desmitis can be a primary cause of lameness in horses and should not be overlooked; critical evaluation on MR is warranted in lameness cases
- •Periligamentous oedema around abaxial ligaments is a useful indicator to prompt closer assessment for desmitis on MR examination
- •Differentiation between specific abaxial ligaments on low-field MR is unreliable; consider high-field imaging or correlation with clinical signs when diagnostic clarity is needed
Key Findings
- •Desmitis of PL-PIPJ was the primary MR finding in 45% (13/29) of clinical cases with lameness
- •Periligamentous oedema was present in 74% (53/71) of abaxially located ligaments with desmitis
- •The abaxial palmar/plantar ligament was distinctly visible in only 5% (4/80) of ligaments on low-field MR, making differentiation challenging
- •Enthesophyte formation occurred in 33% (34/102) of ligaments with desmitis