Brindley, G. W.

The effects of alterations in serum calcium levels on the volume of distribution of a calcium tracer in bone and on bone blood flow were investigated in dogs by manipulation of parathyroid status. The volume of distribution increases with increasing serum calcium. This implies that there is a concentration-dependent binding mechanism in the extravascular space of bone, which is not saturated at the levels of serum calcium achieved in these experiments. The skeletal exchangeable calcium was increased in hypercalcemic dogs and decreased in hypocalcemic dogs. Cancellous bone contains proportionately more exchangeable calcium than cortical bone. Bone blood flow was decreased by 50% 15 min after injection of a bolus of parathyroid hormone (PTH) but returned to control values by 240 min. Fifty-two hours after the induction of hypercalcemia with repeated doses of PTH, there was no difference in blood flow over control animals.

Forty-one patients with 42 involved feet received local care for neuropathic foot disease. Thirty-one patients had ulcers (nine with associated fractures), and 10 did not (eight with fracture and two with severe ligamentous injury). Patients were examined at least 1 year after initiation of treatment, and follow-up averaged 3 years (range, 1 to 9). Treatment included ulcer cleansing, debridement, local bone excision, molded plaster casts, and antibiotics for patients with significant infection. Most patients used special shoes. Of the 42 involved extremities, 39 (93%) healed with treatment, 21 extremities (50%) remained healed at follow-up examination, and 16 patients (39%) continue to have difficulty with recurrent foot ulceration or osteoarthropathy. Thirty-nine patients (95%) have avoided the need for a major amputation.