Diagnosing diabetic foot osteomyelitis: is the combination of probe-to-bone test and plain radiography sufficient for high-risk inpatients?

• Published in: Diabetic medicine Vol. 28; no. 2; pp. 191 - 194
• Main Authors: Aragón-Sánchez, J., Lipsky, Benjamin A., Lázaro-Martínez, J. L.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.02.2011; Blackwell
• Subjects: Biological and medical sciences; Bone; Bone and Bones - pathology; Data processing; Diabetes mellitus; Diabetes Mellitus, Type 2 - complications; Diabetes Mellitus, Type 2 - pathology; Diabetes Mellitus, Type 2 - physiopathology; Diabetes. Impaired glucose tolerance; diabetic foot; Diabetic Foot - diagnosis; Diabetic Foot - pathology; Diabetic Foot - physiopathology; diabetic foot infection; Endocrine pancreas. Apud cells (diseases); Endocrinopathies; Etiopathogenesis. Screening. Investigations. Target tissue resistance; Feeding. Feeding behavior; Female; Foot; foot ulcer; Fundamental and applied biological sciences. Psychology; Hospitals; Humans; Infection; Inpatients - statistics & numerical data; Ionizing radiation; Male; Medical sciences; Osteomyelitis; Osteomyelitis - complications; Osteomyelitis - diagnosis; Osteomyelitis - diagnostic imaging; Osteomyelitis - pathology; Predictive Value of Tests; probe-to-bone test; Radiography; Risk; Risk groups; Sensitivity and Specificity; Vertebrates: anatomy and physiology, studies on body, several organs or systems; Vertebrates: endocrinology; Endocrinopathy; Plain film; High risk; Skin disease; Diabetic Foot; foot ulcer; Diseases of the osteoarticular system; Probe; Osteoarticular system; Osteitis; Disease of the foot; Ulcer; Diagnosis; Hospital; Nutritional status; Human; Obesity; Nervous system diseases; Radiodiagnosis; Nutrition; Diabetes mellitus; Nutrition disorder; Exploration; Metabolic diseases; Hospitalization; Infection; osteomyelitis; Medical imagery; Bone; probe-to-bone test; Endocrinology; diabetic foot infection
• ISSN: 0742-3071; 1464-5491
• DOI: 10.1111/j.1464-5491.2010.03150.x

Diabet. Med. 28, 191–194 (2011) Aims  To investigate the accuracy of the sequential combination of the probe‐to‐bone test and plain X‐rays for diagnosing osteomyelitis in the foot of patients with diabetes. Methods  We prospectively compiled data on a series of 338 patients with diabetes with 356 episodes of foot infection who were hospitalized in the Diabetic Foot Unit of La Paloma Hospital from 1 October 2002 to 31 April 2010. For each patient we did a probe‐to‐bone test at the time of the initial evaluation and then obtained plain X‐rays of the involved foot. All patients with positive results on either the probe‐to‐bone test or plain X‐ray underwent an appropriate surgical procedure, which included obtaining a bone specimen that was processed for histology and culture. We calculated the sensitivity, specificity, predictive values and likelihood ratios of the procedures, using the histopathological diagnosis of osteomyelitis as the criterion standard. Results  Overall, 72.4% of patients had histologically proven osteomyelitis, 85.2% of whom had positive bone culture. The performance characteristics of both the probe‐to‐bone test and plain X‐rays were excellent. The sequential diagnostic approach had a sensitivity of 0.97, specificity of 0.92, positive predictive value of 0.97, negative predictive value of 0.93, positive likelihood ratio of 12.8 and negative likelihood ratio of 0.02. Only 6.6% of patients with negative results on both diagnostic studies had osteomyelitis. Conclusions  Clinicians seeing patients in a setting similar to ours (specialized diabetic foot unit with a high prevalence of osteomyelitis) can confidently diagnose diabetic foot osteomyelitis when either the probe‐to‐bone test or a plain X‐ray, or especially both, are positive.