Arthritis of the subtalar joint associated with sustentaculum tali facet configuration.

The articular facets of the sustentaculum tali have a variety of configurations that are generally viewed as nonmetric traits of little functional significance. Bruckner (1987), in contrast, has hypothesised that sustentaculum tali facet variations are functionally important because they influence subtalar joint stability. To test this hypothesis, 191 calcanei were analysed for correlations between sustentaculum tali facet morphology and osteoarthritis of the subtalar joint. Calcanei with 2 separate sustentaculum tali facets had a lower frequency of arthritic changes associated with joint instability than calcanei with other facet configurations. This finding supports Bruckner's hypothesis that subtalar joint facet configuration is a factor in foot mobility.