Presentation
Fall from step with hyperflexion of the ankle. Pain to the posterior ankle.
Patient Data
Left image: radiograph demonstrating swelling within Kager's fat pad. Several small bone fragments which represent Achilles tendon enthesophytes are displaced superiorly.
Right image: a prior normal radiograph performed 3 years earlier which showed a normal position of the enthesophytes.
Appearance is suggestive of tear/avulsion of the Achilles tendon.
There are fluid and debris within Kager's fat pad and mild associated hyperemia. The tendon is discontinuous. Approximately 2.8 mm of the tendon appears intact at the level of the tear. Bone fragments are seen ~32 mm from the insertion of the tendon.
Appearances are in keeping with a partial tendon tear.
Case Discussion
Achilles tendon tears typically occur 2-6 cm from the tendon insertion where there is reduced vascularity. Tears can be classified by using the Kuwada classification system where grade I represents a partial rupture (<50%) and grade V indicates a complete rupture with tendon gap >6 cm.
Partial tears may be treated conservatively.