Amputation stumps studied by bone scanning. Work in progress

Nine diabetic and 7 nondiabetic (post-trauma) patients 24 to 63 years of age (mean, 49) were scanned following amputation below the knee, which was bilateral in 4. A three-phase scanning technique (flow, blood pool, and delayed equilibrium images) was employed, using Tc-99m-etidronate. Duration of the arterial and capillary phases was estimated during flow. Activity at the tip of the stump was plotted as a function of (a) time since amputation and (b) flow measurements. Activity was found to diminish over a period of nearly 50 months, usually becoming minimal or undetectable after 18 months. The stump demonstrated relative stasis compared to the intact limb, particularly in diabetics and patients with long-standing amputation.