Fatigue perturbation of the os calcis.

This paper represents a philosophical shift in thinking. The authors propose that heel spur syndrome is not a primary soft tissue injury (i.e., enthesiopathy with concomitant bruising of the bursae and fat pad, and eventually the formation of a traction spur by the pull of the plantar fascia), but rather a primary bone injury. A microtrabecular stress failure (fatigue perturbation) of the os calcis occurs with secondary soft tissue involvement such as enthesiopathy, periostitis, myositis, bursitis, and finally the formation of a buttress callous (bone spur) to stabilize a microcortical crack. This study describes four stages in a progressive, sequential, pattern of fatigue failure of the os calcis. Clinical symptoms for each stage, along with supporting data such as x-rays, bone scans, and MRIs will be presented, as well as a suggested treatment plan for the chronic resistant cases.