technetium-tc-99m-medronate and Diabetic-Neuropathies

Early and accurate diagnosis of infection or neuropathy of the diabetic foot is the key to successful management. Angiopathy leads to ischemia which, in combination with peripheral neuropathy, predisposes to pedal skin ulceration, the precursor of osteomyelitis. Chronic hyperglycemia promotes production of glycosylated end products which accumulate on endothelial proteins, causing ischemia of the vasa nervorum. When combined with axonal degeneration of the sensory nerves, the result is hypertrophic neuroarthropathy. Should the sympathetic nerve fibers also be damaged, the resultant loss of vasoconstrictive impulses leads to hyperemia and atrophic neuroarthropathy. Plain radiography, although less sensitive than radionuclide, magnetic resonance (MR), and computed tomographic examinations, should be the initial procedure for imaging suspected osteomyelitis in the diabetic patient. If the radiographs are normal but the clinical suspicion of osteomyelitis is strong, a three-phase 99mTc-MDP scan or MR imaging is recommended. An equivocal 99mTc-MDP scan should be followed by MR imaging. To exclude osteomyelitis at a site of neuroarthropathy, a 111In white blood cell scan is preferable. To obtain a specimen of bone for bacteriological studies, percutaneous core biopsy is the procedure of choice, with the entrance of the needle well beyond the edge of the subjacent ulcer.

Topics: Biopsy, Needle; Diabetic Angiopathies; Diabetic Foot; Diabetic Neuropathies; Diagnostic Imaging; Female; Foot Diseases; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Osteomyelitis; Radionuclide Imaging; Technetium Tc 99m Medronate; Tomography, X-Ray Computed

Topics: Aged; Diabetic Neuropathies; Diagnosis, Differential; Gallium Radioisotopes; Humans; Indium; Joint Diseases; Leukocytes; Male; Middle Aged; Osteomyelitis; Radioisotopes; Radionuclide Imaging; Technetium Tc 99m Medronate

Topics: Diabetic Foot; Diabetic Neuropathies; Edema; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Radiopharmaceuticals; Technetium Tc 99m Medronate

We reviewed all patients with a clinically infected foot ulcer attending a specialised neuropathic foot clinic. Neuropathy was confirmed by the inability to feel a 5.07 Semmes-Weinstein hair, areflexia and impaired vibration sense, as measured by a biothesiometer. Of 40 patients who attended the clinic over a two-year period, six with ischaemic ulcers were excluded. The remaining 34 had plain radiographs of the foot followed by a 99mTc-MDP bone scan. If the latter was positive, an 111In-labelled WBC scan was performed with planar and/or tomographic dual-isotope studies where appropriate. Bone and WBC scans were performed in 31 patients. In ten, isotope imaging showed infection localised to the soft tissues only and conservative treatment was successful in them all. Eighteen patients were treated surgically with excision of the involved bone, which was sent for culture and histological examination. Dual-isotope scans had a sensitivity of 93% and a specificity of 83%. 99mTc-MDP bone scans with the appropriate In-labelled WBC scans can reliably determine the site and extent of osteomyelitis in the neuropathic diabetic foot.

Topics: Bone and Bones; Diabetic Foot; Diabetic Neuropathies; Humans; Indium Radioisotopes; Leukocytes; Osteomyelitis; Radiography; Radionuclide Imaging; Sensitivity and Specificity; Technetium Tc 99m Medronate

Six patients with soft tissue injury secondary to different etiologic factors are presented. The degree and extent of tissue necrosis was precisely identified by scintigraphy. In two of these, radionuclide imaging helped to establish accurately the level of amputation that resulted in appropriate wound healing.

Topics: Adult; Burns, Electric; Child Abuse; Child, Preschool; Diabetic Neuropathies; Diphosphates; Humans; Male; Radionuclide Imaging; Rhabdomyolysis; Technetium; Technetium Tc 99m Medronate; Technetium Tc 99m Pyrophosphate

Diagnosis of osteomyelitis of the foot in diabetic patients may be difficult because of the coexistence of chronic cellulitis, vascular insufficiency, and peripheral neuropathy. This study compared the diagnostic accuracies of plain films, bone scans, and MR imaging studies in diabetic patients with suspicion of osteomyelitis of the foot. Twenty-nine plain radiographs, 20 bone scans, and 30 MR studies were obtained in 24 patients. Twenty-nine bones from 14 patients were pathologically proved either positive (25 bones) or negative (four bones) for osteomyelitis. Another 15 bones (10 patients) studied with MR had no pathologic proof, but the bones healed with only local wound care and/or a short course of oral antibiotics. These patients had trauma, cellulitis, or unhealed ulcers. The sensitivity and specificity of plain films were both 75%. Bone scans had a very low specificity (100% false-positive rate). A negative bone scan should strongly exclude the probability of osteomyelitis. Unlike the findings in previous reports, MR had much higher sensitivity and specificity than bone scans in detecting osteomyelitis in diabetic patients. When the 10 patients without pathologic proof (those who presumably had neuroarthropathy, vascular insufficiency, and/or cellulitis) were included, the sensitivity and specificity of all three techniques decreased. Our experience with this small group of patients suggests that MR is a useful imaging technique for diagnosing osteomyelitis of the foot in diabetic patients.

Topics: Adult; Aged; Diabetes Mellitus, Type 1; Diabetic Neuropathies; Female; Foot; Foot Diseases; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Osteomyelitis; Radiography; Radionuclide Imaging; Sensitivity and Specificity; Technetium Tc 99m Medronate

Six diabetic patients with roentgenographic finding of osteomyelitis, osteoarthropathy, or both, had combined leukocyte and bone imaging. Bone images demonstrated increased activity in all cases, including three without osteomyelitis. Leukocyte images, however, showed increased activity in only the three cases of osteomyelitis. There was minimal or no activity in the other three cases where osteoarthropathy was ultimately believed to be the basis of the roentgenographic and bone imaging changes.

Topics: Arthropathy, Neurogenic; Bone and Bones; Diabetic Neuropathies; Female; Foot Diseases; Humans; Indium Radioisotopes; Isotope Labeling; Leukocytes; Middle Aged; Osteomyelitis; Radionuclide Imaging; Technetium Tc 99m Medronate

It is difficult to diagnose osteomyelitis in the presence of neurotrophic osteoarthropathy. We performed combined [99mTc]MDP bone scans and indium-111 (111In) leukocyte studies on 35 patients who had radiographic evidence of neuropathic foot disease and clinically suspected osteomyelitis. The [111In]leukocyte study determined if there was an infection and the bone scan provided the anatomic landmarks so that the infection could be localized to the bone or the adjacent soft tissue. Seventeen patients had osteomyelitis and all showed increased [111In]leukocyte activity localized to the bone, giving a sensitivity of 100%. Among the 18 patients without osteomyelitis, eight had no accumulation of [111In]leukocytes, seven had the [111In]leukocyte activity correctly localized to the soft tissue, two had [111In]leukocyte activity mistakenly attributed to the bone, and one had [111In]leukocyte accumulation in a proven neuroma which was mistakenly attributed to bone. These three false-positive results for osteomyelitis reduced the specificity to 83%. Considering only the 27 patients with a positive [111In]leukocyte study, the combined bone scan and [111In]leukocyte study correctly localized the infection to the soft tissues or bone in 89%. Uninfected neurotrophic osteoarthropathy does not accumulate [111In]leukocytes. We found the combined bone scan and [111In] leukocyte study useful for the detection and localization of infection to soft tissue or bone in patients with neuropathic foot disease.

Topics: Adult; Aged; Bone and Bones; Diabetic Neuropathies; Female; Foot Diseases; Humans; Indium Radioisotopes; Leukocytes; Male; Middle Aged; Osteomyelitis; Radionuclide Imaging; Technetium Tc 99m Medronate

Topics: Diabetic Neuropathies; Diagnosis, Differential; Diphosphonates; Foot Diseases; Gallium Radioisotopes; Humans; Osteomyelitis; Radionuclide Imaging; Skin Ulcer; Technetium; Technetium Tc 99m Medronate

Bone scans of patients with diabetic osteoarthropathy of the ankle and foot were characterized by a combination of diffuse and focal increased uptake, similar to that seen with hyperemia and reactive new bone formation. Scintigraphy showed more extensive abnormalities than radiography, with the scan abnormalities sometimes preceding the radiographic changes. The clinical and scintigraphic appearance of osteoarthropathy may improve following strict diabetic control and non-weight-bearing.

Topics: Adult; Aged; Ankle; Bone Diseases; Diabetic Neuropathies; Diphosphonates; Female; Foot; Humans; Joint Diseases; Male; Middle Aged; Radiography; Technetium; Technetium Tc 99m Medronate