Comparison of palpation and ultrasonography findings in supraspinous ligaments of horses.

Overview

• This study evaluates how effective palpation (manual examination) is in detecting injuries to the supraspinous ligament in horses compared to ultrasonography, a diagnostic imaging method.
• The researchers retrospectively analyzed clinical and ultrasound data to determine how well palpation identifies ligament abnormalities, focusing on its sensitivity and specificity.

Introduction and Purpose

• The supraspinous ligament (SSL) runs along the dorsal midline of a horse’s spine and is important for spinal stability.
• Injuries to the SSL can cause back pain and limit a horse’s mobility, impacting performance and welfare.
• Currently, diagnosis primarily involves clinical examination combined with ultrasonography to visualize ligament structure.
• Prior to this study, no research had specifically assessed the value of palpation (feeling for physical signs like swelling or pain) as a stand-alone diagnostic tool for SSL injuries.
• The aim was to determine how reliably palpation can detect SSL pathology, and its potential role alongside ultrasound.

Methods

• The study retrospectively reviewed records of 126 horses presented for back problems at a veterinary teaching hospital.
• Key inclusion criteria required cases where:
  • The clinician documented palpation findings of the dorsal midline (areas overlying the SSL).
  • The horses underwent ultrasonographic examination of the SSL at the same visit.
• Palpation findings recorded included:
  • Presence of swelling
  • Pain or tenderness
  • Temperature differences
  • Other abnormal physical signs
• Ultrasound findings were categorized by location along the spine: thoracic (mid-back) or lumbar (lower back) regions.
• The diagnostic performance of palpation versus ultrasound was assessed through:
  • Sensitivity (ability to correctly identify true positives)
  • Specificity (ability to correctly identify true negatives)
  • Positive Predictive Value (PPV) and Negative Predictive Value (NPV)

Results

• Palpation demonstrated:
  • High sensitivity, meaning it was good at detecting horses with SSL pathology.
  • Lower specificity, indicating it sometimes identified abnormalities that were not confirmed by ultrasound (false positives).
• Palpation was especially effective at detecting swelling related to SSL pathology in the thoracic spine region.
• A positive finding on palpation should prompt further diagnostic imaging using ultrasonography to confirm SSL injury.

Conclusions and Clinical Significance

• Palpation is a useful initial screening tool for supraspinous ligament injuries due to its high sensitivity, particularly in the thoracic spine.
• Because of its lower specificity, a positive palpation result alone is not definitive and necessitates follow-up ultrasonographic evaluation to make an accurate diagnosis.
• Veterinarians can use palpation to identify horses at risk or suspected of SSL pathology and decide when further imaging is required.
• This study fills an important gap by formally investigating palpation’s diagnostic value for SSL injuries in horses.