- Exam Findings:
- note that active plantarflexion may occur due to activity of tibialis posterior, peroneals, and long toe flexors;
- diagnosis is clinched w/ one of two tests;
-
hyper-dorsiflexion sign:
- the patient is placed in the prone position, and the knees are flexed to 90 deg;
- the examiner then passively dorsiflexes both feet maximally and compares the injured to the non injured side;
-
Thompson Test:
- have the patient prone w/ both feet extending past end of examing table;
- calf muscles on the affected side are squeezed by the examiner;
- if tendon is intact, the foot will plantar flex, & conversely if tendon is ruptured, the foot will not contract;
- this text may lose accuracy after one week from injury;
-
O'brien's needle test:
- 25 gauge needle is inserted at right angle thru skin of calf muscle just medial to midline at point 10 cm proximal to superior border of calcaneus;
- needle tip should be just w/ in substance of the tendo calcaneus;
- motion of the hub of the needle in a direction opposite that of the tendon during passive dorsiflexion and
plantarflexion of the foot confirms an intact tendon distal to the level of needle insertion;
-
location of tear:
- palpate tendon for site of maximal tenderness and fullness;
- usually tears occur 2-3 cm above the calcaneal insertion;
-
estimate size of defect:
- a large defect may have a worse prognosis w/ non operative treatment (as compared to a rupture w/ a small defect);
The needle test
for complete rupture of the Achilles tendon.
Technical Tip: Hyperdorsiflexion sign in tears of the tendo achilles.
MS Davies et al.
Foot and Ankle Int. Sep 1998. p 647.
