Simultaneous ruptures of the palmar carpal ligament and superficial digital flexor tendon in a traction horse
Authors: G. L. B. L. Pizzi, R. Blake, D. Cavalcante, Karina Holz, L. A. Rafael, Charles Ferreira Martins
Journal: Medicina Veterinária (UFRPE)
Summary
# Editorial Summary A 13-year-old mixed-breed gelding presented with bilateral forelimb lameness and severe carpal hyperextension following simultaneous rupture of the left palmar carpal ligament and right superficial digital flexor tendon, a rare concurrent injury pattern in equine practice. Clinical examination revealed pronounced swelling, heat and pain across both thoracic limbs, with radiographic analysis demonstrating severe radiocarpal hyperextension (225° on the right, 235° on the left) and lateral subluxation of the carpal-ulnar bones; post-mortem findings confirmed partial multifocal tearing of the palmar carpal ligament on the left and complete rupture of the superficial digital flexor tendon on the right. This case highlights the critical biomechanical interdependence of the palmar carpal ligament and superficial digital flexor tendon in preventing carpal hyperextension—a synergistic relationship that, when compromised bilaterally, results in devastating joint instability. Whilst individual superficial digital flexor tendon ruptures may be managed surgically, complete palmar carpal ligament rupture typically results in irreversible carpal damage and functional incapacity, frequently necessitating euthanasia. Practitioners should recognise that concurrent or sequential injuries to these structures in working horses (particularly traction animals) represent a poor prognostic indicator, warranting careful consideration of treatment viability and animal welfare from initial presentation.
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Practical Takeaways
- •Simultaneous ruptures of the palmar carpal ligament and superficial digital flexor tendon can occur and represent a devastating injury with poor prognosis due to the synergistic biomechanical role of these structures in preventing carpal hyperextension.
- •Severe carpal hyperextension (>220°) combined with carpal subluxation on radiographs indicates catastrophic ligamentous and/or tendinous failure requiring immediate intervention and likely euthanasia.
- •Traction work may predispose to these concurrent injuries; practitioners should be alert to signs of carpal pain, swelling, heat, and reluctance to move as early warning signs of potential ligament/tendon compromise.
Key Findings
- •A 13-year-old gelding presented with simultaneous ruptures of the left palmar carpal ligament and right superficial digital flexor tendon, resulting in severe carpal hyperextension (235° and 225° angles respectively).
- •Radiographic examination revealed lateral subluxation of the carpal-ulnar bone and severe hyperextension of the radiocarpal joint bilaterally.
- •Post-mortem examination confirmed partial multifocal tearing of the palmar carpal ligament on the left and complete tearing of the superficial digital flexor tendon on the right.
- •Complete palmar carpal ligament rupture typically results in irreparable joint damage and euthanasia, despite availability of tendon rupture treatments.