Computed tomography derived bone density measurement in the diabetic foot

Radiodensity Analysis of Lateral Column Superconstruct Fixation Sites in Midfoot Charcot Neuroarthropathy

Lateral column deterioration and subsequent loss of function poses a challenge for limb preservation in patients with Charcot neuroarthropathy (CN). Application of "superconstructs" provides stability and clinical improvement to an often-ulcerated lateral foot. This study examines radiodensity in Hounsfield units (HU) to compare bone quality of lateral column fixation targets using computed tomography (CT) scans between patients with and without midfoot CN. A retrospective chart review identified control (nondiabetic, non-CN; n = 29) and midfoot CN (n = 21) groups. Patient demographics and medical history were collected. Two reviewers measured the mean HU of circular regions of interest centered on the fourth and fifth metatarsal heads as well as the anterior, middle, and posterior thirds of the calcaneus. Radiodensity was compared between groups, among calcaneal locations, Eichenholtz stages and Brodsky types. A p value ≤.05 was considered statistically significant. Age and body mass index were not significantly different between groups. The CN group exhibited greater HU than the control group at the metatarsal head and calcaneus (p < .001). The anterior calcaneus exhibited greater HU than the posterior calcaneus in the CN group (p = .02). The difference in HU was not statistically significant between Stages 0-1 and Stages 2-3 or midfoot Brodsky Types. Indirect bone density analysis revealed an increased density in CN compared to control patients with no significant difference between midfoot CN stages or types. The anterior calcaneus was the densest rearfoot bone among the CN patients, a result that may have implications in surgical fixation.

Correlation of Lisfranc Injuries With Regional Bone Density

Lisfranc injuries present a challenge due to their ubiquity though frequent missed diagnoses. A paucity of data exists associating the contribution of bone density to injury type. This investigation compares the regional bone density between Lisfranc injury types using computed-tomography (CT)-derived Hounsfield units. A retrospective chart review identified patients with gross ligamentous and avulsion-type Lisfranc injuries determined by CT examination of the second metatarsal base and medial cuneiform. Regional bone density was assessed by averaging the Hounsfield units of the first metatarsal base, navicular, cuboid, calcaneus, and talus between 2 reviewers. Density was compared between injury type, isolated concomitant forefoot, and mid/hindfoot fractures. One hundred thirty-four patients were separated into avulsion (n = 85) and ligamentous (n = 49) groups. No statistically significant difference in patient body mass index, age, smoking status, or Quenu and Kuss injury pattern was observed between groups. The regional bone density of the cuboid (p = .03) and talus (p = .04) was greater in the ligamentous group. Lower extremity concomitant mid/hindfoot fracture patients exhibited greater regional bone density in the ligamentous group in all assessed bones (p ≤ .04) except the calcaneus. Ligamentous injuries of the Lisfranc complex are associated with increased regional bone density among patients sustaining concomitant mid/hindfoot fractures. This study expands the utility of regional bone density analysis in foot and ankle trauma.

Radiodensity Analysis of Medial Column Superconstruct Fixation Sites in Midfoot Charcot Neuroarthropathy

Charcot neuroarthropathy (CN) is a highly destructive, pathologic process with devastating consequences to foot structure and viability. The use of intramedullary fixation "superconstructs" allows for "re-bar" support of compromised bone and allows for some dynamic fixation. This study examines radiodensity in Hounsfield units (HU) to compare bone quality of medial column fixation targets using computed tomography scans between patients with and without midfoot CN. A retrospective chart review identified control (nondiabetic, non-CN; n = 29) and midfoot CN (n = 21) groups. Patient demographics and medical history were collected. Two reviewers measured the mean HU of a circular region of interest centered on the first metatarsal head and the anterior, middle, and posterior thirds of the talar body. Radiodensity was compared between groups, and among talar locations, Eichenholtz stages and Brodsky types, with statistical significance set at p ≤ .05. Age and body mass index were not significantly different between groups. The CN group maintained greater mean HU than the control group at the metatarsal head (p < .001), and talar body locations (p < .019). The difference in mean HU of these bones was not statistically significant between Stages 0 to 1 and Stages 2 to 3 or Brodsky Types 1 and 2. Mean HU differences among talus positions were not statistically significant. Indirect bone density analysis using HU showed an increased density in CN patients with no significant difference among talar body locations or midfoot Charcot stages and types. These results may assist in optimizing fixation length. Future studies may examine these densities in ankle CN.

Micro-CT analysis of the Lisfranc complex reveals higher bone mineral density in dorsal compared to plantar regions

Injuries to the Lisfranc complex may require surgical fixation, the stability of which may be correlated with bone mineral density (BMD). However, there is limited research on regional BMD variations in the Lisfranc complex. This study used quantitative micro-CT to characterize regional BMD in the four bones (medial cuneiform, intermediate cuneiform, first metatarsal, and second metatarsal) of this complex. Twenty-four cadaveric specimens were imaged with a calibration phantom using micro-CT. Each bone was segmented and divided into eight regions based on an anatomical coordinate system. BMD for each octant was calculated using scan-specific calibration equations and average image intensity. Differences between regions were analyzed using ANOVA with post hoc analysis and differences between groups of four octants in each plane were analyzed with t-tests with significance level α = 0.05. The highest density region in the medial cuneiform was the distal-dorsal-lateral and dorsal regions showed significantly higher BMD than plantar regions. The intermediate cuneiform had the highest density in the distal-dorsal-medial region and the dorsal and medial regions had higher BMD than the plantar and lateral regions, respectively. The densest region of the first metatarsal was the distal-dorsal-lateral and distal regions had significantly higher BMD than proximal regions. In the second metatarsal, the distal-dorsal-medial region had the highest density, and the distal, dorsal, and medial regions had significantly higher BMD than the proximal, plantar, and lateral regions, respectively. The predominant finding was a pattern of increased density in the dorsal bone regions, which may be relevant in the surgical management of Lisfranc injuries.

Trabecular bone mineral density correlations using QCT: Central and peripheral human skeleton

Musculoskeletal injuries to the lower leg and foot-ankle joint are associated with external mechanical loads resulting from motor vehicle crashes, under body blasts, falls from height, or sports. As an intrinsic material property, the bone mineral density (BMD) is related to bone strength. The clinically recognized biological sites for BMD evaluation are the hip and spine. The focus of this study was to define the correlation between BMD from standard clinical sites (hip and lumbar spine) compared to BMD from non-standard sites (foot-ankle-distal tibia bones). Twenty-one post-mortem human subjects (PMHS) with mean age, height, and mass of 63 ± 11 years, 179 ± 7 cm, and 86 ± 13 kg, respectively were used for analysis. Clinical BMD software (Mindways Software, Inc.) was used for trabecular BMD quantification using quantitative computed tomography (QCT). In quantification of BMD of the foot-ankle-distal tibia (hind foot), the trabecular BMD of the talus (316 ± 86mg/cc) was highest followed by the distal tibia (238 ± 72 mg/cc) and then calcaneus (147 ± 51 mg/cc). To correlate BMD values from foot bone regions with the central skeleton BMD values within the same PMHS, there were 18 lumbar spine and 12 hip BMDs available. The BMD of the distal tibia correlated best with the hip intertrochanter BMD (R² of 0.72). Calcaneus BMD best correlated with the hip femoral neck BMD (R² = 0.64). In summary, the hind foot bone BMD values correlated better with the hip as compared to the lumbar spine BMD from the same PMHS. These findings indicate that, in the absence of a direct measure of foot-bone BMD, hip BMD might be a better predictor of injury risk to hind foot rather than lumbar spine BMD, or alternatively, calcaneal trabecular BMD can be used to predict the risk of injury to hip. Further, these relationships between central and peripheral regions can also be implemented in finite element models for improved failure predictions.

Comprehensive treatment of diabetic hallux gangrene with lower extremity vascular disease: A case report

Diabetic foot is a serious complication in patients with diabetes. It is caused by diabetes combined with lower extremity vascular lesions and neuropathy so that a wound does not heal for a long time. In severe cases, it may lead to bone marrow infection and bone destruction, with a high disability and fatality rate. This report describes the case of a patient with diabetic hallux gangrene with lower extremity vascular disease, which was treated by surgical debridement, ozone therapy, and vascular interventional surgery. Using this treatment, the diabetic foot can be cured better and faster, and a satisfactory effect can be achieved.

The Significant Correlation Between the Density of the Cochlea Otic Capsule and Spine in Hearing Loss Patients

Osteoporosis and osteopenia are systemic disorders that affect all bones. Osteoporosis in the ear bone and cochlea otic capsule contribute to the occurrence of conduction and sensorineural deaf. The osteoporosis prevalence in RSSA is 38%; meanwhile hearing interference in osteoporosis patients is 66.67%. The femur and spine DXA are the golden standard to calculate the bone mineral density. The temporal bone density can be measured with CT scan using the Hounsfield Unit units. There is a hypothesis that the femur bone mass density can illustrate the temporal bone density. This study aimed to analyzes the correlation between the density of the cochlea otic capsule and the ear bone towards the femur and spine density in patients with reduction in bone density. This was a cross-sectional observational type analytic retrospective study analyzing 30 samples of patients with a reduction in bone density that have HRCT Mastoid examination results during 2017 at RSSA Malang's osteoporosis polyclinic. From 30 samples, most were female with an age range of 51-60 years old. The average femur, spine, ear bone and cochlea otic capsule of the osteoporosis group was lower than the osteopenia group. The spine density was significantly correlated with the otic capsule density. There was a positive significant correlation between the spine density towards the otic capsule density. The lower the spine density, the lower the otic capsule became.

Patient-Specific Phantomless Estimation of Bone Mineral Density and Its Effects on Finite Element Analysis Results: A Feasibility Study

Objectives

This study proposes a regression model for the phantomless Hounsfield units (HU) to bone mineral density (BMD) conversion including patient physical factors and analyzes the accuracy of the estimated BMD values.

Methods

The HU values, BMDs, circumferences of the body, and cross-sectional areas of bone were measured from 39 quantitative computed tomography images of L2 vertebrae and hips. Then, the phantomless HU-to-BMD conversion was derived using a multiple linear regression model. For the statistical analysis, the correlation between the estimated BMD values and the reference BMD values was evaluated using Pearson's correlation test. Voxelwise BMD and finite element analysis (FEA) results were analyzed in terms of root-mean-square error (RMSE) and strain energy density, respectively.

Results

The HU values and circumferences were statistically significant (p < 0.05) for the lumbar spine, whereas only the HU values were statistically significant (p < 0.05) for the proximal femur. The BMD values estimated using the proposed HU-to-BMD conversion were significantly correlated with those measured using the reference phantom: Pearson's correlation coefficients of 0.998 and 0.984 for the lumbar spine and proximal femur, respectively. The RMSEs of the estimated BMD values for the lumbar spine and hip were 4.26 ± 0.60 (mg/cc) and 8.35 ± 0.57 (mg/cc), respectively. The errors of total strain energy were 1.06% and 0.91%, respectively.

Conclusions

The proposed phantomless HU-to-BMD conversion demonstrates the potential of precisely estimating BMD values from CT images without the reference phantom and being utilized as a viable tool for FEA-based quantitative assessment using routine CT images.

[New progress in the treatment of chronic wound of diabetic foot]

Diabetic foot is one of the serious complications of diabetic patients. It is caused by diabetes combined with different degrees of lower extremity vascular lesions and neuropathy, and the wound can not heal for a long time. The serious results can cause bone marrow infection, bone destruction, and have high disability and death rate. At present, there are various treatment methods for diabetic foot chronic wound. On the basis of internal medicine controlling blood sugar, anti infection, lowering blood lipid, improving microcirculation and nourishment nerve, the surgical method is adopted, including the debridement of the necrosis in a short time to prevent the infection from spreading; maggot biological debridement and ozone chemical debridement will promote the growth of granulation tissue while controlling infection. Skin grafting, skin flap transplantation, skin distraction closure can be used to repair soft tissue defects, or fat transplantation, platelet-rich plasma, and rich blood are used for the refractory wound after infection control. In patients with diabetic foot, the reconstruction of lower limb blood supply is beneficial to the recovery of chronic ischemic wounds. It is feasible to improve the blood supply of the lower extremities, improve the blood supply of the lower extremity artery bypass grafting, and improve the microcirculation of the peripheral vessels around the lower extremities. Lower extremity vascular bypass pressure perfusion therapy for vascular network expansion, tibia lateral moving technique for lower limb microcirculation reconstruction. For diabetic foot ulcer caused by peripheral neuropathy, such as Charcot foot, while the application of external fixator, total contact cast technology of affected foot for reducing treatment to promote wound healing; the preparation of orthopedic shoes can play a maximum protective effect on the healing of diabetic foot wound healing.

Technologies to monitor the health of loaded skin tissues

There are many situations where the skin and underlying soft tissues are compromised by mechanical loading in the form or pressure, or pressure in combination with shear. If sustained, this can lead to damage in the tissues particularly adjacent to bony prominences, resulting in chronic wounds. An array of bioengineering technologies have been adopted to assess the integrity of loaded soft tissues. This paper aims to review these approaches for the quantification, simulation and early detection of mechanically-induced skin damage. The review considers different measurements at the interface between the skin and support surface/medical device, involving pressure, shear, friction and the local microclimate. The potential of the techniques to monitor the physiological response of the skin to these external stimuli including biophysical measurement devices and sampling of biofluids are critically analysed. In addition, it includes an analysis of medical imaging technologies and computational modelling to provide a means by which tissue deformation can be quantified and thresholds for tissue damage defined. Bioengineering measurement and imaging technologies have provided an insight into the temporal status of loaded skin. Despite the advances in technology, to date, the translation to clinical tools which are robust and cost effective has been limited. There is a need to adapt existing technologies and simulation platforms to enable patients, carers and clinicians to employ appropriate intervention strategies to minimise soft tissue damage.

Fully automated segmentation of a hip joint using the patient-specific optimal thresholding and watershed algorithm

BACKGROUND AND OBJECTIVE

Automated segmentation with high accuracy and speed is a prerequisite for FEA-based quantitative assessment with a large population. However, hip joint segmentation has remained challenging due to a narrow articular cartilage and thin cortical bone with a marked interindividual variance. To overcome this challenge, this paper proposes a fully automated segmentation method for a hip joint that uses the complementary characteristics between the thresholding technique and the watershed algorithm.

METHODS

Using the golden section method and load path algorithm, the proposed method first determines the patient-specific optimal threshold value that enables reliably separating a femur from a pelvis while removing cortical and trabecular bone in the femur at the minimum. This provides regional information on the femur. The watershed algorithm is then used to obtain boundary information on the femur. The proximal femur can be extracted by merging the complementary information on a target image.

RESULTS

For eight CT images, compared with the manual segmentation and other segmentation methods, the proposed method offers a high accuracy in terms of the dice overlap coefficient (97.24 ± 0.44%) and average surface distance (0.36 ± 0.07 mm) within a fast timeframe in terms of processing time per slice (1.25 ± 0.27 s). The proposed method also delivers structural behavior which is close to that of the manual segmentation with a small mean of average relative errors of the risk factor (4.99%).

CONCLUSION

The segmentation results show that, without the aid of a prerequisite dataset and users' manual intervention, the proposed method can segment a hip joint as fast as the simplified Kang (SK)-based automated segmentation, while maintaining the segmentation accuracy at a similar level of the snake-based semi-automated segmentation.