What is the approach to assessing an Achilles tendon?

Assessment of Achilles Tendon

The most effective approach to assessing the Achilles tendon includes examination maneuvers that simulate tendon loading to reproduce pain, palpation for gaps or tenderness, specific clinical tests like the Thompson/Simonds squeeze test, and imaging with ultrasound or MRI when diagnosis remains unclear. 1

Physical Examination Components

Essential Clinical Tests

• Thompson/Simonds squeeze test: Squeeze the calf muscle while the patient is prone with feet hanging off the examination table. Lack of plantar flexion indicates a complete rupture
• Palpation: Check for a palpable gap along the tendon course (indicative of rupture)
• Range of motion: Assess for increased passive ankle dorsiflexion with gentle manipulation
• Strength testing: Evaluate decreased ankle plantar flexion strength

These combined tests yield sensitivity values of 73-84% and specificity of 77-78% for diagnosing acute Achilles tendon rupture 1.

Pain Provocation Tests

• Load the tendon through:
  • Single-leg heel raises
  • Hopping
  • Jumping
  • Eccentric loading exercises

Pain reproduction during these maneuvers helps confirm tendinopathy 1.

Imaging Modalities

When clinical diagnosis is unclear, imaging should be utilized:

1. Ultrasound:

   • 92% sensitivity for differentiating full versus partial tears
   • 58% sensitivity and 94% specificity for tendinopathy
   • Advantage: Can be performed as point-of-care assessment in emergency settings 1, 2

2. MRI:

   • 95% sensitivity and 95% specificity for Achilles tendon injuries
   • Particularly useful for complex or unclear cases 1

3. Plain radiography:

   • Helpful to rule out other pathologies (fractures, calcifications)
   • Not the primary diagnostic tool for tendon assessment 1

Diagnostic Pitfalls to Avoid

1. Misdiagnosing tendinopathy as tendonitis: Most cases labeled as "tendonitis" are actually degenerative conditions (tendinosis/tendinopathy) rather than inflammatory processes 1

2. Inadequate examination: Failing to perform a complete set of diagnostic tests can lead to missed diagnoses, particularly in partial tears 1

3. Overlooking bilateral involvement: Bilateral tendon damage is common in Achilles tendon injuries, even when symptoms appear unilateral 1

4. Relying solely on patient history: Physical examination and objective testing are essential for accurate diagnosis 1, 3

Comprehensive Assessment Algorithm

1. Begin with history:

   • Mechanism of injury (sudden pain/pop vs. gradual onset)
   • Activity level and recent changes in training
   • Location of pain (insertional vs. midportion)
   • Aggravating and relieving factors

2. Perform physical examination:

   • Visual inspection for swelling, ecchymosis
   • Palpation for gaps, nodules, or thickening
   • Thompson/Simonds squeeze test
   • Range of motion and strength testing
   • Pain provocation with tendon loading

3. Consider imaging based on clinical findings:

   • If acute rupture is suspected: Ultrasound or MRI
   • If chronic tendinopathy: Ultrasound initially, MRI for complex cases
   • If diagnosis remains unclear after clinical examination: MRI

4. Document findings systematically:

   • Location of pathology (insertional vs. midportion)
   • Presence/absence of rupture
   • Degree of functional impairment
   • Pain levels during specific activities

This structured approach ensures comprehensive assessment and guides appropriate treatment planning, whether conservative management or surgical intervention is indicated 1, 4.