Talus Visualization in Ankle Fractures: How Much Are We Really Seeing?

BACKGROUND

Despite appropriate care, a subset of patients with ankle fractures has persistent pain. This condition may be associated with intra-articular pathology, which is present up to 65% of the time.

PURPOSE

To quantify how much of the talus is visible through an open approach to a standard supination external rotation bimalleolar ankle fracture as a percentage of the entire weightbearing surface of the talus.

STUDY DESIGN

Descriptive laboratory study.

METHODS

Standard ankle approaches to lateral and medial malleolar fractures were performed in 4 cadaveric ankles from 2 cadavers. Osteotomies were made to simulate a supination external rotation bimalleolar ankle fracture based on the Lauge-Hansen classification. The visible segments of talar cartilage were removed. The tali were then exhumed, and the entire weightbearing superior portion of the talus was assessed and compared with the amount of cartilage removed by an open approach. The mean of the data points as well as the 95% confidence interval were calculated.

RESULTS

Four ankle specimens from 2 cadavers were used for these measurements. The mean surface area of the talus was 14.0 cm (95% CI, 13.3-14.7 cm), while the mean area visible via an open approach was 2.1 cm (95% CI, 0.5-3.6 cm). The mean proportion of the talus visualized via an open approach was 14.8% (95% CI, 3.6-26.1%).

CONCLUSION

These findings indicate that the true area of weightbearing talar surface visible during an open exposure may be less than what many surgeons postulate.

CLINICAL RELEVANCE

Only a small fracture of the talus is visible via an open approach to the talus during fracture fixation. This could warrant arthroscopic evaluation of these injuries to evaluate and treat osteocondral lesions resulting from ankle fractures.