Achilles Tendon Rupture: Radiography

Radiographic findings in achilles tendon rupture include:

• Obscuration of the tendon: Bleeding, edema and loss of the tendon cause obscuration of the anterior margin on the Achilles tendon on the lateral view.
• Posterior encroachment on the Kager fat pad: Blood and edema encroach on the Kager fat pad. The fat pad is narrowed by edema,
• Skin indentation at the rupture site: Not a great example here, but a small dimple (white arrow) can be seen at the rupture site. Usually obscured by swelling and hemorrhage.
• Soft-tissue mass at the tendon ends: The ends of the ruptured tendon retract and coil, resulting in swelling at the tendon ends. Look for the tendon rupture site in the zone of relative avascularity 2–6 cm from the calcaneal insertion.
• Identification of the severed ends: When widely separated, the tendon ends may be visualized. The proximal end is usually obscured by swelling and hemorrhage, but the distal end can be separated from the surrounding fat in 50% of cases.

References

Reveno PM, Kittleson AC. Spontaneous Achilles' tendon rupture. Radiology. 1969 Dec;93(6):1341-4.