Ryan T. Crews

Clinical effectiveness of an acellular dermal regenerative tissue matrix compared to standard wound management in healing diabetic foot ulcers: a prospective, randomised, multicentre study

This 12‐week, prospective, randomised, controlled multi‐centre study compared the proportion of healed diabetic foot ulcers and mean healing time between patients receiving acellular matrix (AM) (study group) and standard of care (control group) therapies. Eighty‐six patients were randomised into study (47 patients) and control (39 patients) groups. No significant differences in demographics or pre‐treatment ulcer data were calculated. Complete healing and mean healing time were 69·6% and 5·7 weeks, respectively, for the study group and 46·2% and 6·8 weeks, respectively, for the control group. The proportion of healed ulcers between the groups was statistically significant (P = 0·0289), with odds of healing in the study group 2·7 times higher than in the control group. Kaplan–Meier survivorship analysis for time to complete healing at 12 weeks showed a significantly higher non healing rate (P = 0·015) for the control group (53·9%) compared with the study group (30·4%). After adjusting for ulcer size at presentation, which was a statistically significant covariate (P = 0·0194), a statistically significant difference in non healing rate between groups was calculated (P = 0·0233), with odds of healing 2·0 times higher in the study versus control group. This study supports the use of single‐application AM therapy as an effective treatment of diabetic, neuropathic ulcers.

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.

Reliability of motor-evoked potentials in the ADM muscle of older adults

The purpose of this study was to determine the reliability of motor-evoked potentials (MEPs) produced in the abductor digiti minimi (ADM) muscle of male and female older adults, both within and between sessions. The number of trials within a session required to obtain reliable results was also examined. The investigation was conducted on 30 elderly individuals (15 M, 15 F; mean age 76 years). With the ADM at rest, MEPs were evoked at intensities of 1.1, 1.3, and 1.5 times motor threshold (MT). Ten stimuli were delivered at each intensity, with 10-12s between stimuli. The MEP responses were blocked with two, three, four, and five-stimuli means in each block. An intraclass correlation (ICC) reliability analysis of variance model was used to assess reliability of the MEP amplitude, using a variable number of trials per block. A subset of 10 subjects repeated the protocol following 20min of rest to assess the reliability between sessions. As expected, MEP amplitudes were significantly higher as stimulus intensity increased. There were no significant differences between blocks, nor was there a significant gender effect. ICC reliability coefficients ranged between 0.09 with two trials per block and 0.97 with five trials per block. Between session reliability ranged from 0.65 to 0.83. Highly reliable MEP amplitudes can be obtained in older individuals using two blocks of TMS stimuli with five trials per block.

A growing troubling triad: diabetes, aging, and falls.

There is a significant and troubling link between diabetes (DM) and falls in the elderly. Individuals with DM are prone to fall for reasons such as decreased sensorimotor function, musculoskeletal/neuromuscular deficits, foot and body pain, pharmacological complications, and specialty (offloading) footwear devices. Additionally, there is some concern that DM patients are prone to have more severe problems with falls than non-DM individuals. Fractures, poorer rehabilitation, and increased number of falls are all concerns. Fortunately, efforts to mitigate falls by DM patients show promise. A number of studies have shown that balance, strength, and gait training may be utilized to successfully reduce fall risk in this population. Furthermore, new technologies such as virtual reality proprioceptive training may be able to provide this reduced risk within a safe training environment.

Can we predict outcome of surgical reconstruction of Charcot neuroarthropathy by dynamic plantar pressure assessment?--A proof of concept study.

The joint deformity that arises as a result of Charcot neuroarthropathy, leads to gait modification. Ulceration risk associated with the deformity is generally assessed by measuring plantar pressure magnitude (PPM). However, as PPM is partially dependent on gait speed and treatment interventions may impact speed, the use of PPM to validate treatment is not ideal. This study suggests a novel assessment protocol, which is speed independent and can objectively (1) characterize abnormality in dynamic plantar loading in patients with foot Charcot neuroarthropathy and (2) screen improvement in dynamic plantar loading after foot reconstruction surgery. To examine whether the plantar pressure distribution (PPD) measured using EMED platform, was normal, a customized normal distribution curve was created for each trial. Then the original PPD was fitted to the customized normal distribution curve. This technique yields a regression factor (RF), which represents the similarity of the actual pressure distribution with a normal distribution. RF values may range from negative 1 to positive 1 and as the value increases positively so does the similarity between the actual and normalized pressure distributions. We tested this novel score on the plantar pressure pattern of healthy subjects (N=15), Charcot patients pre-operation (N=4) and a Charcot patient post-foot reconstruction (N=1). In healthy subjects, the RF was 0.46+/-0.1. When subjects increased their gait speed by 29%, PPM was increased by 8% (p<10(-5)), while RF was not changed (p=0.55), suggesting that RF value is independent of gait speed. In preoperative Charcot patients, the RF<0, however, RF increased post-surgery (RF=0.42), indicating a transition to normal plantar distribution after Charcot reconstruction.

Use of chlorhexidine-impregnated patch at pin site to reduce local morbidity: the ChIPPS Pilot Trial.

Pin tract infection is one of the most common complications associated with the use of external fixation. While some studies have identified the potential benefit of chlorhexidine gluconate‐impregnated polyurethane dressings to reduce the incidence of catheter‐related bloodstream infections, we are unaware of any published studies that evaluate the effectiveness of similar technologies in reducing the risk for external‐fixation‐related pin tract infections. Therefore, the purpose of this study was to evaluate the effectiveness of chlorhexidine gluconate‐impregnated polyurethane dressing in reducing percutaneous‐device‐related skin colonisation and local infections. In this initial retrospective cohort, data were abstracted for two groups of consecutive patients undergoing surgery involving external fixation at an interdisciplinary foot and ankle surgical unit. All patients received surgical treatment of their foot/ankle pathology along with application of a hybrid external fixator. Twenty patients (45% male, age 54·5 ± 3·69 years) received chlorhexidine gluconate‐impregnated polyurethane dressing and twenty (55% male, age 55·8 ± 3·22 years) received standard pin care. There was a significantly higher rate of pin tract infection in patients who received standard pin care compared with those who received chlorhexidine gluconate‐impregnated polyurethane dressings (25% versus 0%, P = 0·047). There was no significant difference in any of the descriptive study characteristics (age, gender, diabetes and presence of neuropathy). The results of this initial study suggest that chlorhexidine gluconate‐impregnated polyurethane dressing may be effective to reduce the incidence of pin tract infections and help decrease morbidity associated with external fixation.

Fear of Falling Is Prevalent in Older Adults with Diabetes Mellitus But Is Unrelated to Level of Neuropathy

BACKGROUND Patients with diabetic peripheral neuropathy (DPN) demonstrate gait alterations compared with their nonneuropathic counterparts, which may place them at increased risk for falling. However, it is uncertain whether patients with DPN also have a greater fear of falling. METHODS A voluntary group of older adults with diabetes was asked to complete a validated fear of falling questionnaire (Falls Efficacy Scale International [FES-I]) and instructed to walk 20 m in their habitual shoes at their habitual speed. Spatiotemporal parameters of gait (eg, stride velocity and gait speed variability) were collected using a validated body-worn sensor technology. Balance during walking was also assessed using sacral motion in the mediolateral and anteroposterior directions. The level of DPN was quantified using vibration perception threshold from the great toe. RESULTS Thirty-four diabetic patients (mean ± SD: age, 67.6 ± 9.2 years; body mass index, 30.9 ± 5.7; hemoglobin A1c, 7.9% ± 2.3%) with varying levels of neuropathy (mean ± SD vibration perception threshold, 34.6 ± 22.9 V) were recruited. Most participants (28 of 34, 82%) demonstrated moderate to high concern about falling based on their FES-I score. Age (r = 0.6), hemoglobin A1c level (r = 0.39), number of steps required to reach steady-state walking (ie, gait initiation) (r = 0.4), and duration of double support (r = 0.44) were each positively correlated with neuropathy severity (P < .05). Participants with a greater fear of falling also walked with slower stride velocities and shorter stride lengths (r = -0.3 for both, P < .05). However, no correlation was observed between level of DPN and the participants actual concern about falling. CONCLUSIONS Fear of falling is prevalent in older adults with diabetes mellitus but is unrelated to level of neuropathy.

Dynamic footprint measurement collection technique and intrarater reliability: ink mat, paper pedography, and electronic pedography.

BACKGROUND Identifying the variability of footprint measurement collection techniques and the reliability of footprint measurements would assist with appropriate clinical foot posture appraisal. We sought to identify relationships between these measures in a healthy population. METHODS On 30 healthy participants, midgait dynamic footprint measurements were collected using an ink mat, paper pedography, and electronic pedography. The footprints were then digitized, and the following footprint indices were calculated with photo digital planimetry software: footprint index, arch index, truncated arch index, Chippaux-Smirak Index, and Staheli Index. Differences between techniques were identified with repeated-measures analysis of variance with post hoc test of Scheffe. In addition, to assess practical similarities between the different methods, intraclass correlation coefficients (ICCs) were calculated. To assess intrarater reliability, footprint indices were calculated twice on 10 randomly selected ink mat footprint measurements, and the ICC was calculated. RESULTS Dynamic footprint measurements collected with an ink mat significantly differed from those collected with paper pedography (ICC, 0.85-0.96) and electronic pedography (ICC, 0.29-0.79), regardless of the practical similarities noted with ICC values (P = .00). Intrarater reliability for dynamic ink mat footprint measurements was high for the footprint index, arch index, truncated arch index, Chippaux-Smirak Index, and Staheli Index (ICC, 0.74-0.99). CONCLUSIONS Footprint measurements collected with various techniques demonstrate differences. Interchangeable use of exact values without adjustment is not advised. Intrarater reliability of a single method (ink mat) was found to be high.

Response to Comment on Crews et al. Role and Determinants of Adherence to Off-loading in Diabetic Foot Ulcer Healing: A Prospective Investigation. Diabetes Care 2016;39:1371–1377

We were pleased that van Netten et al. (1) appreciate the importance of our article (2) substantiating the relationship between adherence to off-loading modalities and healing of diabetic foot ulcers (DFUs). Their letter contained several comments regarding our article that we address here. The first comment by van Netten et al. is regarding the rationale for using a surrogate clinical outcome (ulcer area reduction) rather than ulcer healing by a fixed time, preferably 12 weeks, which would allow for direct comparisons with other articles on off-loading. It is important to note, as was outlined in our article, that the study associated with our publication was not limited …

Clinical factors associated with a conservative gait pattern in older male veterans with diabetes

BackgroundPatients with diabetes and peripheral neuropathy are at higher risk for falls. People with diabetes sometimes adopt a more conservative gait pattern with decreased walking speed, widened base, and increased double support time. The purpose of this study was to use a multivariate approach to describe this conservative gait pattern.MethodsMale veterans (mean age = 67 years; SD = 9.8; range 37–86) with diabetes (n = 152) participated in this study from July 2000 to May 2001 at the Veterans Affairs Medical Center, White River Junction, VT. Various demographic, clinical, static mobility, and plantar pressure measures were collected. Conservative gait pattern was defined by visual gait analysis as failure to demonstrate a heel-to-toe gait during the propulsive phase of gait.ResultsPatients with the conservative gait pattern had lower walking speed and decreased stride length compared to normal gait. (0.68 m/s v. 0.91 m/s, p < 0.001; 1.04 m v. 1.24 m, p < 0.001) Age, monofilament insensitivity, and Rombergs sign were significantly higher; and ankle dorsiflexion was significantly lower in the conservative gait pattern group. In the multivariate analysis, walking speed, age, ankle dorsiflexion, and callus were retained in the final model describing 36% of the variance. With the inclusion of ankle dorsiflexion in the model, monofilament insensitivity was no longer an independent predictor.ConclusionOur multivariate investigation of conservative gait in diabetes patients suggests that walking speed, advanced age, limited ankle dorsiflexion, and callus describe this condition more so than clinical measures of neuropathy.