Tali Articular Facets on the Calcanei of Adult Nigerians

The patterns of articulating facets between the talus and the calcaneus have been studied in various geographic population groups (Sudanese, Indian, Egyptian, Spanish, and British populations). The posterior articulating facets on the calcaneus for the talus articulate in a regular manner. However, the anterior and middle facets on the calcaneus for the talus show variation causing various researchers to group them into types and subtypes as observed. The variation in talar articular facets on sample of 74 male adult Nigerian calcanei (aged 18 years and above) was observed and classified. Four distinct faceted patterns were seen and identified. Type 1(64.86%, 48 cases) showed a continuous facet of the middle and anterior, Type II showed a separate anterior and middle facets with variable degree of separation and thus grouped into 3 subtypes. Subtype 11A (10.8%, 8 cases) showed a moderate degree of separation, subtype 11B (8.10%, 6cases) showed a wide separation, while subtype 11C (5.4%, 4cases) showed a narrow separation. Subtype 111 (9.46%, 7cases) showed a single well-defined facet on the sustentaculum tali. Type 1V calcanei have a single facet on the sustentaculum tali extending into the anterior medial corner of the distal part of the calcaneus, but this facet is continuous with the posterior talar facet of the calcaneus (1.35%, 1case) subsequently, the various calcanei were group into right and left and percentages of incidences calculated. This present study shows a remarkable correspondence between our Nigerian sample and those of Indians with type 1 being more frequent (64.86%, 48 cases), type 11 in second place (24.3%, 18cases), types III and IV (9.46%, 7cases) and (1.35%, 1 case) respectively.

Key Words: calcaneus, talus, facetal pattern, Nigerian