The articular facets of the sustentaculum tali
have different configurations, but because they influence subtalar joint stability they are functionally important (Anjaneyulu et al.).
Plain radiographs "on releve." In talo-calcaneal coalition, a "Csign" can be seen (B), caused by fusion of the inferomedial border of the talus with the sustentaculum tali
of the calcaneus.
In the other model the calcaneus was fixated with the same AO calcaneal plate together with an additional screw being infiltrated into the sustentaculum tali. The two models were simulated under the same loading and the displacement of the fracture line and the stress distribution in the two models were calculated respectively.
Results: The maximum principal stress focused on the cortical bone of sustentaculum tali in both the models under the same loading.
Conclusions: The placement of sustentaculum tali screw is essential for fixation of type II calcaneal fracture to achieve the biomechanical stability.
KEY WORDS: Calcaneal fracture; Sustentaculum tali; Screws; Finite element analysis; Biomechanics.
However as the powerful tendons and ligaments in the surrounding of the sustentaculum tali the displacement of the sustentaculum tali rarely occurs in the calcaneal fracture which might provide powerful fixation site for the screws to obtain stable fixation in biomechanics.3 Up to now the relative biomechanical research of the fixation of the sustentaculum tali is seldom reported.
(18) Absent visibility of the subtalar facets (usually middle subtalar facet) and a dysmorphic sustentaculum tali
are also helpful in diagnosing talocalcaneal coalition on a lateral x-ray of the foot, however the accuracy of these signs can be confounded by the direction of the x-ray beam.
The secondary signs for talocalcaneal coalitions were: hypo/dysplastic sustentaculum tali ("drunken waiter" sign) (9) (Figs.
Nearly all the talocalcaneal/subtalar coalitions demonstrated a hypo/dysplastic sustentaculum tali, where the upturned or downturned sustentaculum can be likened to a "drunken waiter" unable to hold his tray at a level position (Fig.
No type 3 (anterior facet was on the sustentaculum tali) of cases was investigated in this study (Fig.
Arthritis of the subtalar joint associated with sustentaculum tali facet configuration.