The role of bone scanning in severe frostbite of the extremities: a retrospective study of 88 cases

We performed a retrospective study of the results of two-phase technetium-9 9m hydroxymethylene diphosphonate bone scans in 88 patients with severe fro stbite of the extremities. All patients were evaluated within 48 h after re warming and all underwent a first bone scan (BS1) within 5 days after rewar ming (median, day 2) (group 1). An excellent correlation was found between absence of tracer uptake in the phalanges and later amputation; this correl ation was especially strong during; the bone phase of the scans (specificit y = 0.99, sensitivity = 0.96, positive predictive value = 0.92). Normal or high uptake in the phalanges was a reliable indicator of ultimate healing ( negative predictive value = 0.99), The sensitivity of the examination was e nhanced by performing a second scan (BS2) more than 5 days (median, day 8) after rewarming (group 2, n=36). h comparative analysis of BS1 and BS2 demo nstrated that some of the lesions continued to evolve between day 2 and day 8. This suggests that the lesions could still be modified during this peri od. On the basis of the findings it is recommended that bone scan he perfor med close to day 2 in all patients who present with lesions extending proxi mally to include the entirety of one or more phalanges. In the case of seve re sepsis, the results of the first bone scan, BS1, can serve as an indicat ion for emergency amputation. BS2 should be performed close to day 8 only i f there is an area of low or absent uptake on BS1. It is concluded that sci ntigraphy is an excellent means of evaluating patients with severe frostbit e of the extremities: as early as day 2 after the injury it can indicate wh ether amputation is necessary, and between days 2 and 8 it provides valuabl e information on the efficacy of treatment.