Concurrent proximal suspensory desmopathy and injury of the proximal aspect of the accessory ligament of the deep digital flexor tendon in forelimbs or hindlimbs in 19 horses
Authors: Plowright E., Dyson S.
Journal: Equine Veterinary Education
Summary
# Editorial Summary Proximal suspensory desmopathy (PSD) is well-established in equine practice, yet concurrent injury to the accessory ligament of the deep digital flexor tendon (ALDDFT) at the proximal aspect has received minimal attention; Plowright and Dyson's retrospective examination of 19 horses (14 with forelimb lameness, 5 hindlimb) sought to characterise the clinical and diagnostic features of this combined pathology. Clinical localising signs proved subtle, appearing in only 7 of 31 lame limbs, with palpable thickening over the ALDDFT region, suspensory ligament pain, or heat in the proximal metacarpal/metatarsal area; diagnostic analgesia varied considerably by limb location, with palmar metacarpal nerve blocks resolving forelimb lameness in 17 of 23 cases, whilst hindlimb cases required deep plantar nerve blocks, tibial blocks, or local infiltration. Ultrasonographically, both structures demonstrated characteristic enlargement, heterogeneous echogenicity and loss of normal linear fibre pattern, with post-mortem examination revealing adhesion formation between the ALDDFT and suspensory ligament in 3 horses—a finding that may be suggested by close structural apposition on ultrasound. The practical significance lies in recognising that PSD with concurrent ALDDFT injury mimics isolated PSD clinically, necessitating systematic and thorough ultrasonographic examination of the entire proximal suspensory apparatus rather than relying solely on palpation or localised imaging.
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Practical Takeaways
- •Concurrent PSD and ALDDFT injury produces clinical signs nearly indistinguishable from isolated PSD, so comprehensive systematic ultrasound examination of the entire proximal metacarpal/metatarsal region is essential for accurate diagnosis
- •Clinical palpation findings are often subtle—don't rely on obvious swelling or heat; use targeted diagnostic analgesia blocks and imaging to confirm diagnosis
- •Ultrasound appearance of close apposition or adhesions between the suspensory ligament and ALDDFT may have prognostic implications and should be documented carefully
Key Findings
- •19 horses with concurrent PSD and ALDDFT injury presented with forelimb (14 horses, 23 limbs) or hindlimb (5 horses, 8 limbs) lameness
- •Clinical signs were subtle in most cases, with localizing signs present in only 7/31 lame limbs including soft tissue thickening and pain on palpation
- •Diagnostic analgesia patterns differed between forelimbs (palmar metacarpal nerve blocks effective in 17/23 limbs) and hindlimbs (deep plantar nerve blocks or local infiltration required)
- •Ultrasonographic findings showed suspensory ligament and ALDDFT enlargement with heterogeneous echogenicity; close apposition of structures may indicate adhesion formation