OBSERVATIONS Probing the Validity of the Probe-to-Bone Test in the Diagnosis of Osteomyelitis of the Foot in Diabetes T he ability to probe the base of a wound to periosteum or bone (the “probe-to-bone” test) is increasingly used to indicate the likelihood of under- lying osteomyelitis. The original study (1) reported sensitivity, specificity, and posi- tive (PPV) and negative (NPV) predictive values of 66, 85, 89, and 56%, respec- tively. However, this work has been crit- icized on the grounds of the high pretest probability of the disease (2), since the prevalence of osteomyelitis in the chosen sample (in-patients with clinically overt infection) was 66%. It follows that the usefulness of the test may be very different in less-selected populations. We have therefore determined the validity of the probe-to-bone test in a consecutive series of outpatients attending our own multi- disciplinary service. A total of 81 patients (with a total 104 foot ulcers) attended the clinic over a 5-week period in May–June 2005. Ulcers were probed by one of two specialist po- diatrists following debridement. The di- agnosis of osteomyelitis was determined by one of two expert diabetologists, who were blind to the results of the probe to bone test. The diagnosis of osteomyelitis was based in each case on the presence of clinical signs of infection (inflammation with or without serous or purulent dis- charge) in association with radiologic ev- idence of bone destruction with interruption of the cortex (either at pre- sentation or at any stage over the ensuing 8 weeks), supported when necessary by magnetic resonance imaging and micro- biologic analysis of deep tissue samples. Those who were diagnosed with osteo- myelitis included those in whom the di- agnosis had already been made at the time of probing and those in whom the diag- nosis was made later. Nineteen (23.5%) patients were diagnosed with osteomyeli- tis complicating foot ulcers, in two of whom bone infection complicated two separate nonadjacent ulcers. Three pa- tients had two or more nonadjacent ul- cers, of which only one was associated with osteomyelitis. A total of 14 patients had osteomyelitis complicating a single ulcer. A total of 21 ulcers (20.2% of 104) were associated with osteomyelitis. The probe-to-bone test was positive in 8 of these 21 ulcers and in 7 of 83 without associated bone infection (sensitivity 38%, specificity 91%). While the NPV was 85%, the PPV (the probability that a patient with a positive test would have osteomyelitis) was only 53%. It is possible that the calculation of both sensitivity and NPV might be in part explained by the fact that some cases of osteomyelitis may already have been responding to treat- ment at the time of probing, but this would not have affected the calculation of either the specificity or the PPV. These data emphasize that the predic- tive value of a positive probe-to bone test in the original report was influenced by the high prevalence of osteomyelitis in the population studied. The prevalence of os- teomyelitis in the present population was still high at 23.5% patients (20.2% ulcers) but was only approximately one-third of that in the earlier study, and the PPV was correspondingly lower. It is likely that the PPV would be lower still in patients man- aged in a less-specialized service. ALISON SHONE, BSC JACLYN BURNSIDE, BSC SUSAN CHIPCHASE, BSC FRAN GAME, FRCP WILLIAM JEFFCOATE, MRCP From the Department of Diabetes and Endocrinol- ogy, Foot Ulcer Trials Unit, City Hospital, Notting- ham, U.K. Address correspondence to William Jeffcoate, Foot Ulcer Trials Unit, Department of Diabetes and Endocrinology, City Hospital, Nottingham NG5 1PB, U.K. E-mail: wjeffcoate@futu.co.uk.. © 2006 by the American Diabetes Association. ●●●●●●●●●●●●●●●●●●●●●●● References 1. Grayson ML, Gibbons GW, Balogh K, Levin E, Karchmer AW: Probing to bone in infected pedal ulcers: a clinical sign of underlying osteomyelitis in diabetic pa- tients. JAMA 273:721–723, 1995 2. Wrobel JS, Connolly JE: Making the diag- nosis of osteomyelitis: the role of preva- lence. J Am Podiatr Med Assoc 88:337– 343, 1998 An Exploratory Study Into the Effectiveness of a Combination of Traditional Chinese Herbs in the Management of Type 2 Diabetes W hile a range of drugs are used to ameliorate the effects of type 2 diabetes and its complications, they tend to slow rather than stop the pro- gression of the disease (1). Many herbs have been used traditionally by different cultures in the management of type 2 di- abetes (2); however, in general there is little scientific evidence to support their efficacy. The aim of this project was to conduct a small-scale trial to examine the effects of a commercial combination of Trichosanthes kirilowii, Polygonatum sibiri- cum, Dioscorea oppostia, Panax ginseng, and Stevia rebaudiona and chromium nic- otinamide (Glucostat; Health World Lim- ited, Eagle Farm, Australia) on type 2 diabetic subjects who are not yet taking orthodox medication. Four male and six female subjects aged between 33 and 70 years who had been diagnosed with type 2 diabetes and were on a low glycemic diet participated in this study. They were administered a 3.2-g dose three times a day over a 90-day period. Fasting blood glucose (FBG) data were collected daily using handheld glu- cometers, and HbA 1c (A1C), cholesterol, and BMI were recorded at the start and end of the trial. This study was approved by the human ethics committee at the University of New England. The mean FBG for all patients at the start of the study was 9.4  1.1 mmol/l and ranged from 7.6 to 11.3 mmol/l. Nine patients responded to the treatment showing a significant, though moderate, de- crease (10  4%) in FBG; however, while A1C, cholesterol, and BMI also declined, this did not reach significance. When treat- ment stopped, FBG rose rapidly over 15–20 days to pretreatment concentrations; how- ever, when treatment was resumed (n = 5) FBG again declined by 14.3% (range 8 –21) over the following 6 weeks. This herbal combination may have some benefit in the treatment of type 2 diabetes, particularly perhaps in the early stages of the disease. The effects, while significant, took time to become appar- L E T T E R S DIABETES CARE, VOLUME 29, NUMBER 4, APRIL 2006 945