How to diagnose an Achilles tendon rupture or calf muscle injury?

From the Guidelines

Diagnosing an Achilles tendon rupture or calf muscle injury requires a detailed history and physical examination, including tests such as the Thompson test, palpation for a gap, and assessment of ankle plantar flexion strength. The physical examination should include two or more of the following tests to establish the diagnosis of acute Achilles tendon rupture: Clinical Thompson test (ie, Simonds squeeze test), decreased ankle plantar flexion strength, presence of a palpable gap (defect, loss of contour), and increased passive ankle dorsiflexion with gentle manipulation 1. For an Achilles tendon rupture, the Thompson test is the primary diagnostic tool - the examiner squeezes the calf muscle while the patient lies face down with feet hanging off the examination table; if the foot doesn't plantarflex (point downward), this indicates a rupture. Other signs include a palpable gap in the tendon, swelling, bruising, and inability to stand on tiptoes.

For calf muscle injuries, diagnosis involves checking for pain, swelling, bruising, and muscle weakness in the calf area. The practitioner will assess the location and severity of pain through palpation and test muscle strength by having the patient perform heel raises. Imaging studies like ultrasound or MRI may be necessary for both conditions to confirm the diagnosis and determine the extent of injury. MRI is particularly useful for visualizing complete versus partial tears 1. Seek immediate medical attention for suspected Achilles ruptures as early treatment (within 48-72 hours) typically yields better outcomes. The distinction between these injuries matters because treatment approaches differ significantly - Achilles ruptures often require immobilization or surgery, while calf strains typically respond to conservative management with rest, ice, compression, and elevation.

Key points to consider in diagnosis include:

• A detailed history and physical examination are essential for diagnosis
• The Thompson test is a primary diagnostic tool for Achilles tendon rupture
• Imaging studies like ultrasound or MRI may be necessary to confirm diagnosis and determine extent of injury
• Early treatment for suspected Achilles ruptures is crucial for better outcomes
• Treatment approaches differ significantly between Achilles ruptures and calf strains, emphasizing the importance of accurate diagnosis.

From the Research

Diagnosing Achilles Tendon Rupture or Calf Muscle Injury

To diagnose an Achilles tendon rupture or calf muscle injury, several methods can be employed, including physical examination, imaging tests, and clinical diagnostic criteria. The following are key points to consider:

• Physical Examination:
  • The Thompson test, also known as the calf squeeze test, is commonly used to assess for Achilles tendon rupture 2, 3.
  • A palpable gap in the tendon and decreased resting tension can also indicate a rupture 3.
  • However, these physical examination maneuvers can be limited by pain and soft tissue swelling, especially in acute injuries 4.
• Imaging Tests:
  • Ultrasound: Has been shown to be very sensitive in detecting Achilles tendon ruptures and can be used for dynamic, real-time examination 2, 4, 5.
  • Magnetic Resonance Imaging (MRI): While MRI can verify an Achilles tendon rupture and provide detailed information about the tendon structure, it may not be necessary for diagnosis in all cases, especially when clinical diagnostic criteria are met 2, 3.
• Clinical Diagnostic Criteria:
  • An abnormal Thompson test, decreased resting tension, and a palpable defect are highly sensitive for diagnosing acute Achilles tendon ruptures 3.
  • These criteria can guide the decision for surgical intervention without the need for MRI in many cases 3.
• Calf Muscle Injuries:
  • Musculoskeletal ultrasound is useful for diagnosing calf injuries, including strains of the gastrocnemius and soleus muscles, by providing dynamic and real-time imaging 5.
  • Ultrasound can help differentiate between musculoskeletal and non-musculoskeletal causes of posterior calf pain and guide management decisions 5.

Key Considerations

• The choice of diagnostic method may depend on the clinical presentation, availability of resources, and the need for detailed imaging to guide treatment decisions.
• Prompt and accurate diagnosis is crucial for effective management and to prevent complications or prolonged recovery times 6, 4, 3, 5.
• Clinical experience and judgment play a significant role in interpreting diagnostic findings and determining the best course of action for each patient 2, 6, 3.