Diagnosis Of Osteomyelitis In The Diabetic Foot With A (99mtc)-Hmpao Leucocyte Scintigraphy Combined With A (99mtc)-Mdp Bone Scintigraphy

Background: The aim of this prospective study was to assess the role of (99mTc)-HMPAO leucocyte scintigraphy combined with a (99mTC)-MDP bone scintigraphy in the diagnosis of the diabetic foot infection (HMPAO-Leu/MDP).Methods: 75 diabetic patients with suspected osteomyelitis were included. The HMPAO-Leu/MDP scan was considered to be consistent with osteomyelitis when the HMPAO-Leu uptake was concordant in all the incidences with an MOP bone uptake. A HMPAO-Leu uptake without concordant bone MOP activity was considered as a soft-tissue infection. The results of the HMPAO-Leu/MDP scan were compared to the following diagnostic criteria: bone infection was confirmed by radiological follow-up or bone biopsy; the absence of bone infection was confirmed by clinical (healing of the ulcer without antibiotherapy) and radiological follow up.Results: According to these criteria, among the 83 ulcers, bone infection was observed in 41(49,4%): the HMPAO-Leu/MDP scan was positive in 38 cases, including 14 ulcers with normal or doubtful radiographs at inclusion. In the group of 42 ulcers without proven bone infection,the HMPAO-Leu/MDP scan was negative in 41 cases, including 17 lesions with a soft-tissue infection.Conclusion: With a sensitivity of 92.6%, a specificity of 97.6%, the HMPAO-Leu/MDP scan is a reliable tool for the diagnosis of osteomyelitis in the diabetic foot. Neuroarthropathy did not affect the performances of the HMPAO-Leu/MDP scan. Owing to a high spatial resolution this test is very helpful to differentiate bone infection from soft-tissue infection especially in case of neuroarthropathy.