Achilles Tendon Tear: Sensitivity and Specificity

Introduction: None written.

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The sensitivity and specificity of findings for Achilles Tendon Tear are listed below. See the left navigation bar to change the display.

Sensitive and Specific Findings

Thompson Test

96%

93%

Also called the "Calf Squeeze test". The patient lies supine and the examiner squeezed the suspected calf inspecting for the presence or absence of plantarflexion. A positive test reveals the absence of plantar flexion and is highly suggestive of an Achilles tendon rupture.

Study: https://pubmed.ncbi.nlm.nih.gov/9548122/

Matles Test

88%

85%

While awake, patients are asked to actively flex their knees to 90°. When the patients are anesthetized, the examiner passively flexes both knees to 90°. In both instances, the position of the ankles and feet is observed during flexion of the knee. If the foot on the affected side falls into neutral or into dorsiflexion, an Achilles tendon tear is diagnosed. On the uninjured side, the foot remains in slight plantar flexion when the knee is flexed to 90°

Study: https://pubmed.ncbi.nlm.nih.gov/9548122/

Poorly Diagnostic Findings

Finding	Sensitivity	Specificity	Comments, Study
Copeland Test	Sensitivity = 80%		With the patient prone, a sphygmomanometer cuff is placed around the middle of the calf and inflated to 100 mm Hg, with the ankle placed in passive plantar flexion by the examiner. The examiner then dorsiflexes the ankle. If the Achilles tendon is intact, dorsiflexion produces a rise in pressure of between 35 and 60 mm Hg. If the tendon is torn, little or no pressure rise is seen. Study: https://pubmed.ncbi.nlm.nih.gov/9548122/
O'Brien Test	Sensitivity = 80%		This test is performed when the patient is either under general or spinal anesthesia as it is considered painful. With the patient prone, a 21-gauge needle is inserted at a right angle through the skin of the calf, just medial to the midline, 10 cm proximal to the superior border of the calcaneus. The needle is inserted only until the tip is just within the tendon. The foot is then passively put through alternately dorsiflexion and plantar flexion. Two responses may occur. The needle may swivel so that it points in the direction opposite to the motion of the ankle (i.e., when the ankle is in dorsiflexion, the needle points distally). This indicates that the tendon is intact in the portion distal to the needle insertion point. The other possible response is that the needle does not move, or moves slightly in the same direction as the motion of the ankle (i.e., when the ankle is in dorsiflexion, the needle does not move, or points slightly proximally). In this second instance, the Achilles tendon has lost its continuity between the needle and its insertion. Study: https://pubmed.ncbi.nlm.nih.gov/9548122/
Palpation	Sensitivity = 73%		The examiner gently palpates the course of the tendon inspecting for a palpable gap in the tendon. The gap is classified as present or absent. A gap is considered positive. Study: https://pubmed.ncbi.nlm.nih.gov/9548122/