In mature dogs with comparable levels of bone remodeling, we produced either increased (with adenosine triphosphate) or decreased (with epinephrine) blood flow to one hindlimb. In 13 dogs (five control, four with increased flow, and four with decreased flow), we compared uptake, at 3 h after injection of radiolabeled diphosphonate in the mid-tibia, with blood flow as determined by microspheres. Blood flow was determined with 85Sr-labeled microspheres, and determination of uptake of 99mTc methylene diphosphonate (99mTc-MDP) was by a gamma detector. There was a linear relationship between changes in diphosphonate uptake and changes in blood flow at decreased and normal flows; however, at high flows the relationship was nonproportional, indicating a disproportionately slower increase in 99mTc-MDP uptake with increasing blood flow. In six dogs an initial 1-h uptake curve of 99mTc-MDP was determined in both control and experimental limbs under states of increased and decreased blood flow. The 30-min uptake value, 60-min uptake value, area under the curve, and the slope of the curve were related to flow as determined by microspheres. The data are consistent with the hypothesis that deposition of bone-concentrating isotopes such as 99mTc-MDP is partly controlled by blood flow; at supranormal and normal flows tracer uptake is closely related to blood flow, but at supranormal flow rates it is not and appears to be diffusion limited.
Three hundred nine McKeever arthrodeses for treatment of the painful hallux were performed on 234 patients at the Mayo Clinic from 1955 to 1980. Two hundred six cases were contacted, and 71 were personally examined and X-rayed. The average follow-up was 15 years (1 to 28 years). Ninety-one percent wore shoes within 2 months, 92% are painless, and 98% without other foot pathology are wearing dress shoes of their choosing. Complications, which consisted of failed fixation, infection, and recurrence of deformity, occurred in 8%. The screw fixation was removed in 30%. Eighty-six percent of the patients are satisfied.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.