James S. Wrobel

Guest editorial: Are diabetes-related wounds and amputations worse than cancer?

Certainly one of the most feared complications of diabetes is the lower extremity amputation (1). This fear is not unwarranted. Diabetesrelated ulcer and amputation may be associated with surprisingly high 5-year mortality. Moulik et al. (2) reported a 5-year mortality of 45%, 18% and 55% for neuropathic, neuroischaemic and ischaemic ulcers, respectively. As expected, mortality was higher in ischaemic ulcers than neuropathic ulcers. However, it is fairly evident based on these data that all types of diabetic foot ulcers are associated with high morbidity and mortality. Similarly, approximately half the persons receiving a diabetesrelated amputation will not be alive in 5 years. Certainly, peripheral vascular disease may be implicated as a significant factor associated with shorter life span. Criqui reported the 10year mortality in patients with peripheral arterial disease and found a substantially higher risk of mortality among patients with large vessel peripheral arterial disease – a factor that may be even more profound today than when it was reported in the early 1990s (3,4). Faglia et al. related this high mortality with the absence of revascularisation, citing a 1.7-fold greater risk for death in ischaemic subjects who might have benefited from intervention (5). How do these data compare with other serious medical conditions, such as cancer? If one reviews Figure 1, one might conclude that persons with lower extremity complications of diabetes have 5-year mortality rates similar or worse than many common types of cancer (6– 10). In fact, some high-risk subgroups such as persons with renal disease requiring distal bypass may have 5-year mortality rates approaching 95% (10).

Diabetic Foot Biomechanics and Gait Dysfunction

Background: Diabetic foot complications represent significant morbidity and precede most of the lower extremity amputations performed. Peripheral neuropathy is a frequent complication of diabetes shown to affect gait. Glycosylation of soft tissues can also affect gait. The purpose of this review article is to highlight the changes in gait for persons with diabetes and highlight the effects of glycosylation on soft tissues at the foot-ground interface. Methods: PubMed, the Cochrane Library, and EBSCOhost® on-line databases were searched for articles pertaining to diabetes and gait. Bibliographies from relevant manuscripts were also searched. Findings: Patients with diabetes frequently exhibit a conservative gait strategy where there is slower walking speed, wider base of gait, and prolonged double support time. Glycosylation affects are observed in the lower extremities. Initially, skin thickness decreases and skin hardness increases; tendons thicken; muscles atrophy and exhibit activation delays; bones become less dense; joints have limited mobility; and fat pads are less thick, demonstrate fibrotic atrophy, migrate distally, and may be stiffer. Interpretation: In conclusion, there do appear to be gait changes in patients with diabetes. These changes, coupled with local soft tissue changes from advanced glycosylated end products, also alter a patients gait, putting them at risk of foot ulceration. Better elucidation of these changes throughout the entire spectrum of diabetes disease can help design better treatments and potentially reduce the unnecessarily high prevalence of foot ulcers and amputation.

Assessing postural control and postural control strategy in diabetes patients using innovative and wearable technology.

Introduction: Currently, diagnosis of patients with postural instability relies on a rudimentary clinical examination. This article suggests an innovative, portable, and cost-effective prototype to evaluate balance control objectively. Methods: The proposed system uses low-cost, microelectromechanical sensor, body-worn sensors (BalanSens™) to measure the motion of ankle and hip joints in three dimensions. We also integrated resulting data into a two-link biomechanical model of the human body for estimating the two-dimensional sway of the center of mass (COM) in anterior-posterior (AP) and medial-lateral (ML) directions. A new reciprocal compensatory index (RCI) was defined to quantify postural compensatory strategy (PCS) performance. To validate the accuracy of our algorithms in assessing balance, we investigated the two-dimensional sway of COM and RCI in 21 healthy subjects and 17 patients with diabetic peripheral neuropathic (DPN) complications using the system just explained. Two different conditions were examined: eyes open (EO) and eyes closed (EC) for duration of at least 30 seconds. Results were compared with center of pressure sway (COP) as measured by a pressure platform (Emed-x system, Novel Inc., Germany). To further investigate the contribution of the somatosensory (SOM) feedback to balance control, healthy subjects performed EO and EC trials while standing on both a rigid and a foam surface. Results: A relatively high correlation was observed between COM measured using BalanSens and COP measured using the pressure platform (r = 0.92). Results demonstrated that DPN patients exhibit significantly greater COM sway than healthy subjects for both EO and EC conditions (p < 0.005). The difference becomes highly pronounced while eyes are closed (197 ± 44 cm2 vs 68 ± 56 cm2). Furthermore, results showed that PCS assessed using RCI is significantly better in healthy subjects compared to DPN subjects for both EO and EC conditions, as well as in both ML and AP directions (p < 0.05). Alteration in SOM feedback in healthy subjects resulted in diminished RCI values that were similar to those seen in DPN subjects (p > 0.05). Discussion/Conclusion: This study suggested an innovative system that enables the investigation of COM as well as postural control compensatory strategy in humans. Results suggest that neuropathy significantly impacts PCS.

The system of care for the diabetic foot: objectives, outcomes, and opportunities

Most cases of lower extremity limb loss in the United States occur among people with diabetes who have a diabetic foot ulcer (DFU). These DFUs and the associated limb loss that may occur lead to excess healthcare costs and have a large negative impact on mobility, psychosocial well-being, and quality of life. The strategies for DFU prevention and management are evolving, but the implementation of these prevention and management strategies remains challenging. Barriers to implementation include poor access to primary medical care; patient beliefs and lack of adherence to medical advice; delays in DFU recognition; limited healthcare resources and practice heterogeneity of specialists. Herein, we review the contemporary outcomes of DFU prevention and management to provide a framework for prioritizing quality improvement efforts within a resource-limited healthcare environment.

Combined Clinical and Laboratory Testing Improves Diagnostic Accuracy for Osteomyelitis in the Diabetic Foot

UNLABELLED The purpose of this investigation was to examine the value of using routinely available clinical and laboratory tests in combination to distinguish osteomyelitis from cellulitis in a diabetic population with mild to moderately infected forefoot ulcers. We conducted a case-control study of 54 diabetic patients with 54 locally infected ulcers admitted to a university-affiliated tertiary-care hospital over a 4.5-year period. A total of 30 clinical and laboratory characteristics obtained at admission were tested for their association with pathology-proven osteomyelitis using logistic regression techniques. Ulcer depth greater than 3 mm (univariate odds ratio 10.4, P = .001) and C-reactive protein greater than 3.2 mg/dL (univariate odds ratio 10.8, P < .001) were the most informative individual clinical and laboratory tests for differentiating osteomyelitis from cellulitis. Adding C-reactive protein also significantly improved upon the accuracy of the studys best clinical testing strategy (area under the curve improved from 0.80 to 0.88, P = .040). Strategies that combined ulcer depth with serum inflammatory markers proved most useful in detecting ulcerated patients with concomitant bone infections (sensitivity 100% [95% CI 89.7%-100%] for both ulcer depth greater than 3 mm or C-reactive protein greater than 3.2 mg/dL, and ulcer depth greater than 3 mm or erythrocyte sedimentation rate greater than 60 mm/h). We conclude that considering clinical and laboratory findings together can significantly improve our diagnostic accuracy for osteomyelitis in the diabetic foot. The specific combination of ulcer depth with serum inflammatory markers appears to be a particularly sensitive strategy that may allow for greater detection of early diabetic osteomyelitis. LEVEL OF CLINICAL EVIDENCE 3.

Laboratory in a box: Wearable sensors and its advantages for gait analysis

Until recently, many gait studies explored potential gait alteration due to various disorders in the gait lab and using camera based systems and force platforms. However, these strategies may not replicate normal outdoor walking. Using this equipment, it is more difficult to measure the variability of walking which is important for maintaining balance and responding to different walking challenges. Additionally, subjects may mask their problem or exaggerate it when they are walking in a short walking distance offered by laboratory based-technology. This study overviews some of the key advantages of wearable technology compared to laboratory-based instrument. Additionally, it explored gait patterns over ample distance of walking compared to walking distance restricted to a gait laboratory environment. Walking patterns of ten healthy young subjects were examined using a wearable sensor technology in a random order over a distance of 7m, 14m, and 20m. Results suggest that participants walk significantly faster by increasing walking distance on average by 15% and 3% when walking distance was increased respectively from 7m to 14 and from 14m to 20m (p<0.05). Interestingly despite a high test-retest reliability for averaged gait parameters (ICC>0.89), the test-retest reliability for gait variability was only acceptable during 20m walking distance (ICC<0.3 for 7m and 14m v. ICC=0.65 for 20m). Taken together, our findings indicate that for valid and reliable assessment of gait parameters, gait should be performed over ample walking distances. Body worn sensor technology facilitates assessing gait outside of a gait laboratory, over ample walking distance, different footwear condition, different walking surface, and in environment where mimics better true environment where the subject is active in.

The Economic Value of Specialized Lower-Extremity Medical Care by Podiatric Physicians in the Treatment of Diabetic Foot Ulcers

BACKGROUND We sought to examine the economic value of specialized lower-extremity medical care by podiatric physicians in the treatment of diabetic foot ulcers by evaluating cost outcomes for patients with diabetic foot ulcer who did and did not receive care from a podiatric physician in the year before the onset of a foot ulcer. METHODS We analyzed the economic value among commercially insured patients and Medicare-eligible patients with employer-sponsored supplemental medical benefits using the MarketScan Databases. The analysis consisted of two parts. In part I, we examined cost or savings per patient associated with care by podiatric physicians using propensity score matching and regression techniques; in part II, we extrapolated cost or savings to populations. RESULTS Matched and regression-adjusted results indicated that patients who visited a podiatric physician had

Collagen-based wound dressings for the treatment of diabetes-related foot ulcers: a systematic review

13,474 lower costs in commercial plans and

Reliability and validity of current physical examination techniques of the foot and ankle.

3,624 lower costs in Medicare plans during 2-year follow-up (P < .01 for both). A positive net present value of increasing the share of patients at risk for diabetic foot ulcer by 1% was found, with a range of

Predicting Development of Proliferative Diabetic Retinopathy

1.2 to