Sub-calcaneal plantar fat pad assessment using dual-energy computed tomography: First experience in the diabetic foot

BACKGROUND

This study assessed the use of dual-energy computed tomography (CT) to evaluate sub-calcaneal plantar fat pad changes in people with diabetic neuropathy.

METHODS

Dual-energy CT scans of people with diabetic neuropathy and non-diabetic controls were retrospectively included. Average CT values (in Hounsfield Units) and thickness (in centimeters) of the sub-calcaneal plantar fat pad were measured in mono-energetic images at two energy levels (40 keV and 70 keV). The CT values measured in patients with diabetic neuropathy were correlated to barefoot plantar pressure measurements performed during walking in a clinical setting.

FINDINGS

Forty-five dual-energy CT scans of people with diabetic neuropathy and eleven DECT scans of non-diabetic controls were included. Mean sub-calcaneal plantar fat pad thickness did not significantly differ between groups (diabetes group 1.20 ± 0.34 cm vs. control group 1.21 ± 0.28 cm, P = 0.585). CT values at both 40 keV (-34.7 ± 48.7 HU vs. -76.0 ± 42.8 HU, P = 0.013) and 70 keV (-11.2 ± 30.8 HU vs. -36.3 ± 27.2 HU, P = 0.017) were significantly higher in the diabetes group compared to controls, thus contained less fatty tissue. This elevation was most apparent in patients with Type 1 diabetes. CT values positively correlated with the mean peak plantar pressure.

INTERPRETATION

Dual-energy CT was able to detect changes in the plantar fat pad of people with diabetic neuropathy.

Preliminary evaluation of dual-energy CT to quantitatively assess bone marrow edema in patients with diabetic foot ulcers and suspected osteomyelitis

OBJECTIVES

The purpose of this study is to evaluate the value of dual-energy CT (DECT) with virtual non-calcium (VNCa) in quantitatively assessing the presence of bone marrow edema (BME) in patients with diabetic foot ulcers and suspected osteomyelitis.

METHODS

Patients with a diabetic foot ulcer and suspected osteomyelitis that underwent DECT (80 kVp/Sn150 kVp) with VNCa were retrospectively included. Two observers independently measured CT values of the bone adjacent to the ulcer and a reference bone not related to the ulcer. The patients were divided into two clinical groups, osteomyelitis or no-osteomyelitis, based on the final diagnosis by the treating physicians.

RESULTS

A total of 56 foot ulcers were identified of which 23 were included in the osteomyelitis group. The mean CT value at the ulcer location was significantly higher in the osteomyelitis group (- 17.23 ± 34.96 HU) compared to the no-osteomyelitis group (- 69.34 ± 49.40 HU; p < 0.001). Within the osteomyelitis group, the difference between affected bone and reference bone was statistically significant (p < 0.001), which was not the case in the group without osteomyelitis (p = 0.052). The observer agreement was good for affected bone measurements (ICC = 0.858) and moderate for reference bone measurements (ICC = 0.675). With a cut-off value of - 40.1 HU, sensitivity was 87.0%, specificity was 72.7%, PPV was 69.0%, and NPV was 88.9%.

CONCLUSION

DECT with VNCa has a potential value for quantitatively assessing the presence of BME in patients with diabetic foot ulcers and suspected osteomyelitis.

KEY POINTS

• Dual-energy CT (DECT) with virtual non-calcium (VNCa) is promising for detecting bone marrow edema in the case of diabetic foot ulcers with suspected osteomyelitis. • DECT with VNCa has the potential to become a more practical alternative to MRI in assessing the presence of bone marrow edema in suspected osteomyelitis when radiographs are not sufficient to form a diagnosis.

Adherence to at-Home Monitoring of Foot Temperatures in People with Diabetes at High Risk of Ulceration

We aimed to investigate adherence to at-home monitoring of foot temperature and its association with patient-, disease- and behavior-related factors, in people with diabetes at high risk of ulceration. We analyzed 151 participants in the enhanced therapy arm of the DIATEMP trial (all at high diabetes-related foot ulcer risk) who aimed to perform and log foot temperatures daily for 18 months or until ulceration. Adherence was the proportion of measurement days covered (PDC), with being adherent defined as PDC≥70%. If a hotspot was recorded, adherence to subsequently reducing ambulatory activity was assessed. Multivariate logistic regression analysis was performed to investigate associations with adherence. We found ninety-four participants (62.3%) adherent to measuring foot temperatures. This was higher in months 1-3 versus months 4-18: 118 (78.1%) versus 78 (57.4%; P < .001). Of 83 participants with a hotspot, 24 (28.9%) reduced ambulatory activity. Increasing age (P = .021, OR = 1.045) and better self-care (P = .007, OR = 1.513) were positively associated with adherence to measuring foot temperature. In conclusion, in people at high diabetes-related foot ulcer risk, adherence to measuring foot temperature was high in the first months after study commencing, but dropped over time. Adherence to reducing ambulatory activity when a hotspot was found was low over the entire study period.

Pressure-reduction and preservation in custom-made footwear of patients with diabetes and a history of plantar ulceration

AIMS

To assess the value of using in-shoe plantar pressure analysis to improve and preserve the offloading properties of custom-made footwear in patients with diabetes.

METHODS

Dynamic in-shoe plantar pressures were measured in new custom-made footwear of 117 patients with diabetes, neuropathy, and a healed plantar foot ulcer. In 85 of these patients, high peak pressure locations (peak pressure > 200 kPa) were targeted for pressure reduction (goal: > 25% relief or below an absolute level of 200 kPa) by modifying the footwear. After each of a maximum three rounds of modifications, pressures were measured. In a subgroup of 32 patients, pressures were measured and, if needed, footwear was modified at 3-monthly visits for 1 year. Pressures were compared with those measured in 32 control patients who had no footwear modifications based on pressure analysis.

RESULTS

At the previous ulcer location and the highest and second highest pressure locations, peak pressures were significantly reduced by 23%, 21% and 15%, respectively, after modification of footwear. These lowered pressures were maintained or further reduced over time and were significantly lower, by 24-28%, compared with pressures in the control group.

CONCLUSION

The offloading capacity of custom-made footwear for high-risk patients can be effectively improved and preserved using in-shoe plantar pressure analysis as guidance tool for footwear modification. This provides a useful approach to obtain better offloading footwear that may reduce the risk for pressure-related diabetic foot ulcers.

An exercise programme for patients with diabetic complications: a study on feasibility and preliminary effectiveness

AIMS

To investigate the feasibility and preliminary effectiveness of an exercise programme for patients with diabetic complications.

METHODS

In this pre-post design study, 22 patients from a diabetic foot outpatient clinic participated in a 12-week individualized exercise programme, consisting of aerobic and resistance exercise, with specific safety precautions. Feasibility was assessed on the basis of programme adherence, adverse events, achievement of the target training intensity and patient satisfaction. Preliminary effectiveness was evaluated with pre-post-changes in blood glucose regulation (HbA(1c) ), muscle strength (isometric peak torque) and perceived limitations in functioning (Patient Specific Function Scale with visual analogue scale).

RESULTS

Twenty patients completed the exercise programme with a high mean attendance (85%). No training-related severe adverse events occurred. The target training intensity was achieved by 70% of the participants. Patient satisfaction was high. HbA(1c) decreased from 8.2% before to 7.8% after the programme (P=0.005), muscle strength increased from 136.4 to 150.4 Nm (P = 0.046) and perceived limitations in functioning decreased from 7.2 to 5.8 mm (P=0.003).

CONCLUSIONS

The prescribed exercise programme had a potentially positive effect on blood glucose regulation, muscle strength and perceived limitations in functioning in patients with diabetic complications.