title: Unsuspected osteomyelitis in diabetic foot ulcers. Diagnosis and monitoring by leukocyte scanning with indium in 111 oxyquinoline.
abstract: OBJECTIVE
  The prevalence of osteomyelitis in diabetic foot ulcers is unknown. Early diagnosis of this infection is critical, as prompt antibiotic treatment decreases the rate of amputation. We therefore assessed the prevalence of osteomyelitis in 35 diabetic patients with 41 foot ulcers. We compared results of roentgenograms, leukocyte scans with indium In 111 oxyquinoline, and bone scans with the diagnostic criterion standards of bone histologic and culture findings. Leukocyte scans were repeated at 2- to 3-week intervals during antibiotic treatment.
  
  
  METHODS
  Cohort study.
  
  
  METHODS
  Institutional and private, ambulatory and hospitalized patients.
  
  
  METHODS
  Consecutive sample of 54 diabetic patients. Thirty-five patients with 41 foot ulcers were included.
  
  
  RESULTS
  As determined by bone biopsy and culture, osteomyelitis was found to underlie 28 (68%) of 41 diabetic foot ulcers. Only nine (32%) of the 28 cases were diagnosed clinically by the referring physician. Underscoring the clinically silent nature of osteomyelitis in these ulcers, 19 (68%) of 28 occurred in outpatients, 19 (68%) of 28 occurred in ulcers not exposing bone, and 18 (64%) of 28 had no evidence of inflammation on physical examination. All patients with ulcers that exposed bone had osteomyelitis. Of the imaging tests, the leukocyte scan had the highest sensitivity, 89%. In patients with osteomyelitis, the leukocyte scan image intensity decreased by 16 to 34 days of antibiotic treatment and normalized by 36 to 54 days.
  
  
  CONCLUSIONS
  The majority of diabetic foot ulcers have an underlying osteomyelitis that is clinically unsuspected. Leukocyte scans are highly sensitive for diagnosing osteomyelitis in diabetic foot ulcers and may be useful for monitoring the efficacy of antibiotic treatment. We recommend that diabetic patients with foot ulcers that expose bone should be treated for osteomyelitis. Diabetic patients with foot ulcers that do not expose bone should undergo leukocyte scanning, which eliminates the risk of bone biopsy in diagnosing osteomyelitis and allows for the diagnosis and treatment of this well-known but often silent precursor of lower extremity amputation.
authors.affiliation: Department of Medicine, Mount Sinai Medical Center, New York, NY 10029.
authors.forename: L G
authors.initials: LG
authors.lastname: Newman
authors.forename: J
authors.initials: J
authors.lastname: Waller
authors.forename: C J
authors.initials: CJ
authors.lastname: Palestro
authors.forename: M
authors.initials: M
authors.lastname: Schwartz
authors.forename: M J
authors.initials: MJ
authors.lastname: Klein
authors.forename: G
authors.initials: G
authors.lastname: Hermann
authors.forename: E
authors.initials: E
authors.lastname: Harrington
authors.forename: M
authors.initials: M
authors.lastname: Harrington
authors.forename: S H
authors.initials: SH
authors.lastname: Roman
authors.forename: A
authors.initials: A
authors.lastname: Stagnaro-Green
mesh_terms: D003924:Diabetes Mellitus, Type 2 / Q000150:complications*; D005534:Foot Diseases / Q000150:complications*; D006801:Humans; D007205:Indium Radioisotopes; D007962:Leukocytes; D008875:Middle Aged; D008991:Monitoring, Physiologic; D010019:Osteomyelitis / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000209:etiology*; D015125:Oxyquinoline; D010808:Physical Examination; D015995:Prevalence; D011877:Radionuclide Imaging; D012883:Skin Ulcer / Q000150:complications*; D013203:Staphylococcal Infections / Q000175:diagnosis
chemical_list: D007205:Indium Radioisotopes; D015125:Oxyquinoline