Suspensory ligament injuries are among the most common soft tissue injuries in equine athletes across all disciplines. Understanding the nature of these injuries, treatment options, and realistic recovery expectations is essential for owners of sport horses.

Anatomy

The suspensory ligament (interosseous muscle) originates at the back of the cannon bone just below the knee (or hock), runs down the back of the leg, and divides into two branches that attach to the sesamoid bones. Its primary role is supporting the fetlock joint during weight bearing.

Types of Injury

Proximal Suspensory Desmitis

Damage to the origin of the ligament, near the knee or hock. This is a common cause of hindlimb lameness and can be challenging to diagnose.

Body Injuries

Tears or inflammation in the main body of the ligament. These are typically identified on ultrasound as areas of fiber disruption.

Branch Injuries

Damage to the medial or lateral branch, often associated with footing conditions and the biomechanics of specific disciplines.

Diagnosis

  • Lameness evaluation with flexion tests
  • Diagnostic anesthesia to localize pain
  • Ultrasound examination — the primary imaging modality for soft tissue evaluation
  • MRI may be recommended for proximal injuries where ultrasound has limitations

Treatment

Treatment depends on the location and severity of injury:

  • Rest and controlled exercise — the foundation of all soft tissue rehabilitation
  • Regenerative therapies — PRP, stem cells for significant fiber damage
  • Shockwave therapy — particularly useful for chronic desmitis
  • Corrective shoeing — addressing biomechanical factors
  • Surgery — fasciotomy or neurectomy in selected chronic cases

Prognosis

Return to athletic use varies by location and severity. Many horses with suspensory injuries return to their previous level of competition with appropriate treatment and rehabilitation. Early diagnosis and disciplined adherence to rehabilitation protocols are the strongest predictors of successful outcomes.

Recovery timelines typically range from 6-12 months depending on the injury severity.