Incidence and Pattern of Calcaneal Spurs in Relation to the Type of Calcaneum: A Dry Bone and Computed Tomography Based Study

Background: Calcaneal spurs, or enthesophytes, are bony outgrowths that develop at the sites of attachment of the plantar fascia and the tendocalcaneus on the calcaneum. They are a recognised cause of chronic heel pain and their occurrence has been variably linked to the configuration of the talar articular facets of the calcaneum, age, sex, obesity and biomechanical loading of the heel. Objective of this study was to study the presence, location and pattern of calcaneal spurs in dry bone specimens and computed tomography (CT) images, and to correlate spur occurrence with the morphological type of calcaneum. Material and Methods: This descriptive cross-sectional study was carried out in the Department of Anatomy in association with the Department of Radiology of a tertiary care teaching institute. Eighty adult dry calcaneum specimens (40 left, 40 right) and fifty CT images (25 males, 25 female) were examined for the presence of plantar (inferior) and dorsal (posterior) spurs. Each bone/image was classified by talar facet type (Bunning and Barnett) as Type A, Type B (subtypes B1-B4) or Type C, and the presence and site of spur formation were recorded and analysed using SPSS version 21. Results: A calcaneal spur was present in 59% of dry bone specimens (31% plantar, 15% dorsal, 13% both) and in 58% of CT images (30% plantar, 14% dorsal, 14% both); spurs were absent in 41-42% of both samples. Spur formation was most frequent in calcanei with fused anterior and middle talar facets (Type B), and plantar spurs were consistently more common than dorsal spurs in both dry bone and CT samples. Right-sided calcanei showed a higher incidence of spur formation than left-sided calcanei, and on CT imaging spurs were marginally more frequent in females (60%) than in males (56%). Conclusion: Calcaneal spur formation is common in this population and shows a clear association with the two-facet (Type B) pattern of the calcaneum, with a consistent predominance of plantar over dorsal spurs. These findings support a biomechanical, vertical-compression-related mechanism of plantar spur formation and are of practical relevance to clinicians managing chronic plantar heel pain and to anatomists and forensic scientists using the calcaneum for age and identification purposes.

Keywords: Calcaneal spur; Enthesophyte; Plantar fasciitis; Calcaneum; Talar articular facet; Heel pain.