Talar neck fracture complicated by avascular necrosis

Case contributed by Dr Yuan Ling

Presentation

Motor vehicle accident.

Patient Data

Age: 30 years
Gender: Male

Comminuted fracture of the talar neck and sustentaculum tali.

X-ray

One week after injury

Two cannulated, headless, fully threaded, variably pitched, tapered compression screws transfix the talar neck.

X-ray

3 months after injury

Hawkins sign (subchondral lucency at the talar dome) reflects disuse osteopenia and is an expected finding that should be sought.

In this case, there is a partial Hawkin sign at the talar dome superolaterally. There appears to be subchondral sclerosis superomedially (absence of Hawkins sign) suspicious of devascularisation.

X-ray

9 months after injury

Subchondral sclerosis at the superomedial talar dome is now more obvious due to progressive demineralization around the region of devascularisation.

In addition, there is now subtle collapse of the articular surface on the lateral projection, indicating avascular necrosis.

MRI

1 year after injury

Geographic subchondral signal abnormality at the talar dome is consistent with avascular necrosis.

Case Discussion

The dominant blood supply of the talus is via the artery of the tarsal canal (branch of the posterior tibial artery), which supplies most of the talar body. The deltoid branch of the PTA supplies part of the medial talar body.
The talar head and neck are supplied by the anterior tibial artery, as well as the artery of the tarsal sinus (branch of a perforating peroneal artery).

Fractures through the tarsal neck may disrupt these vessels, particularly if displaced. Absence of Hawkins sign raises the suspicion of devascularisation and subsequent development of avascular necrosis.

PlayAdd to Share

Case information

rID: 69282
Published: 7th Jul 2019
Last edited: 14th Aug 2019
Inclusion in quiz mode: Included

Updating… Please wait.

 Unable to process the form. Check for errors and try again.

 Thank you for updating your details.