MEDIAL ARTERY CALCIFICATION OF THE 1ST DORSAL METATARSAL ARTERY AS AN INDICATOR OF DIABETIC PERIPHERAL VASCULAR DISEASE

Abstract

Introduction: Mönckeberg sclerosis or medial artery calcification (MAC) is a well known phenomenon associated with the diabetic and other altered blood parameters. However its consequence within the foot and specifically the 1st dorsal metatarsal artery has not previously been studied.

Materials and Methods: Nearly 1000 foot x-rays were studied over a nine month period in a busy District General Hospital to identify the prevalence of first dorsal metatarsal artery calcification. The electronic medical notes for all the patients were reviewed to confirm which patients were known to be diabetic. The patients with positive findings were then identified and their HbA1c, creatinine, and previous foot interventions recorded.

Results: 1.4% of the population studied had medial artery calcification of the 1st dorsal metatarsal artery. 93% were known diabetics and 100% had impaired glucose tolerance (a glucose plasma concentration of > 7.8mmol/l two hours post glucose loading). 79% have required previous podiatric care for foot ulceration and 64% had required surgical intervention for their diabetic feet. MAC has a high positive predictive value (92.9% (95% CI 69.2–98.7)) for diabetes, with a good specificity (99.9% (95%CI 99.4–100)) and low false positive rate (0.1% (05%CI 0.0–0.6)).

Discussion: Medial artery calcification in the first dorsal metatarsal artery is characteristic of impaired glucose metabolism, and if seen on routine x-ray should be an indication for screening of the patient. It should also be considered as a foot at risk sign in the established diabetic due to the high incidence of foot ulceration and need for surgical intervention in this group.

Conclusion: The prevalence of MAC seen on routine foot x-rays has been demonstrated in a large cohort of patients. The specificity and positive predictive value for diabetes has been calculated and the prevalence of these patients requiring surgical or specialist podiatric care recorded.