Neuropathy, claw toes, intrinsic muscle volume, and plantar aponeurosis thickness in diabetic feet

Extracellular matrix-inspired biomaterials for wound healing

Diabetic foot ulcers (DFU) are a debilitating and life-threatening complication of Diabetes Mellitus. Ulceration develops from a combination of associated diabetic complications, including neuropathy, circulatory dysfunction, and repetitive trauma, and they affect approximately 19-34% of patients as a result. The severity and chronic nature of diabetic foot ulcers stems from the disruption to normal wound healing, as a result of the molecular mechanisms which underly diabetic pathophysiology. The current standard-of-care is clinically insufficient to promote healing for many DFU patients, resulting in a high frequency of recurrence and limb amputations. Biomaterial dressings, and in particular those derived from the extracellular matrix (ECM), have emerged as a promising approach for the treatment of DFU. By providing a template for cell infiltration and skin regeneration, ECM-derived biomaterials offer great hope as a treatment for DFU. A range of approaches exist for the development of ECM-derived biomaterials, including the use of purified ECM components, decellularisation and processing of donor/ animal tissues, or the use of in vitro-deposited ECM. This review discusses the development and assessment of ECM-derived biomaterials for the treatment of chronic wounds, as well as the mechanisms of action through which ECM-derived biomaterials stimulate wound healing.

Use of computed tomography to identify muscle quality subgroups, spatial mapping, and preliminary relationships to function in those with diabetic peripheral neuropathy

BACKGROUND

Decreased muscle volume and increased muscle-associated adipose tissue (MAAT, sum of intra and inter-muscular adipose tissue) of the foot intrinsic muscle compartment are associated with deformity, decreased function, and increased risk of ulceration and amputation in those with diabetic peripheral neuropathy (DPN).

RESEARCH QUESTION

What is the muscle quality (normal, abnormal muscle, and adipose volumes) of the DPN foot intrinsic compartment, how does it change over time, and is muscle quality related to gait and foot function?

METHODS

Computed tomography was performed on the intrinsic foot muscle compartment of 45 subjects with DPN (mean age: 67.2 ± 6.4 years) at baseline and 3.6 years. Images were processed to obtain volumes of MAAT, highly abnormal, mildly abnormal, and normal muscle. For each category, annual rates of change were calculated. Paired t-tests compared baseline and follow-up. Foot function during gait was assessed using 3D motion analysis and the Foot and Ankle Ability Measure. Correlations between muscle compartment and foot function during gait were analyzed using Pearson's correlations.

RESULTS

Total muscle volume decreased, driven by a loss of normal muscle and mildly abnormal muscle (p<0.05). MAAT and the adipose-muscle ratio increased. At baseline, 51.5% of the compartment was abnormal muscle or MAAT, increasing to 55.0% at follow-up. Decreased total muscle volume correlated with greater midfoot collapse during gait (r = -0.40, p = 0.02). Greater volumes of highly abnormal muscle correlated with a lower FAAM score (r = -0.33, p = 0.03).

SIGNIFICANCE

Muscle volume loss may progress in parallel with MAAT accumulation, impacting contractile performance in individuals with DPN. Only 48.5% of the DPN intrinsic foot muscle compartment consists of normal muscle and greater abnormal muscle is associated with worse foot function. These changes identify an important target for rehabilitative intervention to slow or prevent muscle deterioration and poor foot outcomes.

Free vascularized fibula leads to hallux toe flexion deformity due to ischemic muscle contracture of flexor hallucis longus

BACKGROUND

This study aimed to investigate the incidence of toe flexion deformity after fibular free flap transplantation and to analyze the etiology of the deformity.

METHODS

Fifty patients underwent vascularized fibular free flap transplantation were retrospectively included. Statistical analysis examined correlations between deformity occurrence and resected fibula length and residual distal fibula length using the χ2 test. Doppler ultrasound and anatomical evaluations were conducted.

RESULTS

Flexion deformity of the first toe was observed in all patients (100%), exacerbated by ankle dorsiflexion. χ2 test revealed no significant correlation between fibula length, distal residual fibula length, and flexion deformity. Doppler ultrasound revealed elevated echoes and blurred textures in the flexor hallucis longus post-fibular transplantation, while anatomical evaluation confirmed the peroneal artery as its primary nutrient supplier.

CONCLUSION

This study reports a 100% incidence of toe flexion deformity post-transplantation. The deformity correlated strongly with ischemic contracture of the flexor hallucis longus.

Leg length discrepancy should be assessed based on the whole length of the lower limb in patients with osteoarthritis secondary to developmental dysplasia of the hip

Aims

This study aimed to investigate the incidence of ≥ 5 mm asymmetry in lower and whole leg lengths (LLs) in patients with unilateral osteoarthritis (OA) secondary to developmental dysplasia of the hip (DDH-OA) and primary hip osteoarthritis (PHOA), and the relationship between lower and whole LL asymmetries and femoral length asymmetry.

Methods

In total, 116 patients who underwent unilateral total hip arthroplasty were included in this study. Of these, 93 had DDH-OA and 23 had PHOA. Patients with DDH-OA were categorized into three groups: Crowe grade I, II/III, and IV. Anatomical femoral length, femoral length greater trochanter (GT), femoral length lesser trochanter (LT), tibial length, foot height, lower LL, and whole LL were evaluated using preoperative CT data of the whole leg in the supine position. Asymmetry was evaluated in the Crowe I, II/III, IV, and PHOA groups.

Results

The incidences of whole and lower LL asymmetries were 40%, 62.5%, 66.7%, and 26.1%, and 21.7%, 20.8%, 55.6%, and 8.7% in the Crowe I, II/III, and IV, and PHOA groups, respectively. The incidence of tibial length asymmetry was significantly higher in the Crowe IV group (44.4%) than that in the PHOA group (4.4%). In all, 50% of patients with DDH-OA with femoral length GT and LT asymmetries had lower LL asymmetry, and 75% had whole LL asymmetry. The incidences of lower and whole LL asymmetries were 20% and 42.9%, respectively, even in the absence of femoral length GT and LT asymmetries.

Conclusion

Overall, 43% of patients with unilateral DDH-OA without femoral length asymmetry had whole LL asymmetry of ≥ 5 mm. Thus, both the femur length and whole LL should be measured to accurately assess LL discrepancy in patients with unilateral DDH-OA.

Managing Cavovarus Feet in Diabetic Patients

A cavovarus foot is characterized by exacerbated medial longitudinal arch (cavus), hindfoot varus, plantar flexed first ray, forefoot pronation (apparent supination), forefoot adduction, and claw toe deformities. It can be broadly divided as flexible and rigid and further classified based on the neurological and non-neurological causes. Diabetes associated peripheral neuropathy complicates individual bony deformities associated with cavovarus foot with early callus which can breakdown to ulceration rapidly. Based on the disease progression in neurological and non-neurological causes of cavovarus feet in patients with diabetic neuropathy, 3 stages of the disease and its management is described.

The impact of diabetic polyneuropathy on toe grip strength in patients with type 2 diabetes mellitus: a cross-sectional study

Purpose

Type 2 diabetes mellitus (T2DM) and concomitant diabetic polyneuropathy (DPN) induce muscle weakness. Muscle weakness in the foot is associated with foot deformities and falls. However, factors affecting toe grip strength (TGS) are not well known. Therefore, the present study investigated factors related to TGS in patients with T2DM.

Methods

This was a cross-sectional study involving 100 patients with T2DM who were hospitalized for the treatment of T2DM and 50 healthy adults. The subjects were divided into three groups: a group of healthy subjects, a group of T2DM patients without DPN, and a group of T2DM patients with DPN. Hierarchical multiple regression analysis was performed with TGS and the TGS-to-weight ratio (TGS/Wt%) as dependent variables and with age, the presence of T2DM, and DPN as independent variables, and sex and BMI as confounders.

Results

There were no significant differences in age or sex among the three groups. In the final regression analysis, age and presence of T2DM and DPN were associated in both models with TGS and TGS/Wt% as dependent variables.

Conclusion

DPN, T2DM, and age were found to be related to TGS. The findings of this study could contribute to healthcare providers developing foot care and rehabilitation programs for diabetic patients.

Trial registration

This study was registered with UMIN-CTR (UMIN000034320) on 1 November 2018.

Prevalence and associated factors of foot deformity among adult diabetic patients on follow-up at Debre Markos comprehensive specialized hospital, Northwest Ethiopia, 2022, cross-sectional study

INTRODUCTION

Diabetes foot deformity is among the major causes of diabetic foot ulceration, resulting in lower limb amputation. However, the study on the distribution of foot deformity and its risk factor among diabetic patients in Ethiopia is limited. This study determined the overall prevalence and associated factors of foot deformity among adult diabetic patients on follow-up at Debre Markos Comprehensive Specialized Hospital, Northwest Ethiopia.

METHODS

Hospital-based cross-sectional study was conducted among 392 diabetic patients using a systematic random sampling technique at Debre Markos Comprehensive Specialized Hospital. Data were collected by pre-tested, semi-structured questionnaires and diabetic foot assessment format. Multivariable binary logistic regression was used to determine the association between dependent and independent variables. Adjusted odds ratios (AOR) with their 95% confidence interval (CI) were used to determine the strength of the association, and a variable with a p-value < 0.05 was statistically significant factors of diabetes foot deformity.

RESULT

The overall prevalence of foot deformity was 33.4% [95% CI: 28.9-38.3]. In the final logistic regression analysis, rural residency [AOR = 2.64, 95% CI: 1.31, 5.31], poor glycemic control [AOR = 2.41; 95% CI: 1.34, 4.33], diabetes duration ≥ 10 years [AOR = 2.74; 95% CI: 1.50, 5.02], inadequate footwear [AOR = 2.11; 95% CI: 1.17, 3.82] and presence of peripheral neuropathy [AOR = 8.21; 95% CI: 4.54, 14.84] were statistically significant associated factors with diabetes foot deformity.

CONCLUSION

The prevalence of foot deformity among adult diabetic patients was high. It is recommended to incorporate foot deformity screening in routine diabetic patient follow-ups especially for those with poor glycaemic control, rural residency, long diabetes duration, inadequate footwear, and diabetic peripheral neuropathy.

A 2-Stage Approach in Managing Diabetic Forefoot Ulcers

BACKGROUND

Forefoot plantar ulcers in patients with diabetic neuropathy are considered to be primarily the result of increased shear forces applied over prominent plantar bony prominences. The purpose of this article is to describe a 2-stage treatment pathway utilizing an outpatient percutaneous tendon-Achilles lengthening (TAL) as the first stage procedure and subsequent proximal metatarsal osteotomy (MTO) as a second stage procedure for a persistent or recurrent ulcer.

METHODS

A consecutive 112 patients (146 feet), who presented to our Multidisciplinary Diabetic Foot Team clinics since February 2019 with plantar nonischemic forefoot ulcers were included in this study. Excluding the patients who died or were lost to follow-up, 96 feet were followed for a minimum 12 months (range 12-36 months). After TAL, patients were encouraged to walk in a walking cast for 6 weeks and were followed for a minimum 12 months. Patients with persistent or recurrent ulcers were investigated with magnetic resonance imaging scan, and based on intramedullary osteomyelitis and septic destruction of distal metatarsal, we describe a second-stage MTO with the 3 most common clinical presentations.

RESULTS

Of 96 feet, none had infection or wound-related problems following TAL. Complete transection of the tendon was noted in 4 patients (4%) and heel callosity in 1 patient. In 92 feet (96%), the ulcers healed within 10 weeks (±4 weeks) after TAL but, in 12 feet (10%), the ulcer failed to heal or recurred. At a minimum 12 months after the second-stage MTO, none in this subgroup had recurrence of ulcer or a transfer lesion.

CONCLUSION

TAL followed with a walking cast as an outpatient procedure was effective in healing forefoot ulcers in 96% of feet. Comparable to the widely practiced hand surgery Wide Awake Local Anesthesia No Tourniquet (WALANT) procedure, our approach involved active control of the degree of ankle dorsiflexion by the patient, and the procedure was proven to be safe and well tolerated. When the second-stage MTO was required to offload the forefoot, in our small cohort, patients had ulcer-free outcome for a minimum 12 months.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

The effect of diabetes and tissue depth on adipose chamber size and plantar soft tissue features

BACKGROUND

Plantar ulceration is a serious complication of diabetes. However, the mechanism of injury initiating ulceration remains unclear. The unique structure of the plantar soft tissue includes superficial and deep layers of adipocytes contained in septal chambers, however, the size of these chambers has not been quantified in diabetic or non-diabetic tissue. Computer-aided methods can be leveraged to guide microstructural measurements and differences with disease status.

METHODS

Adipose chambers in whole slide images of diabetic and non-diabetic plantar soft tissue were segmented with a pre-trained U-Net and area, perimeter, and minimum and maximum diameter of adipose chambers were measured. Whole slide images were classified as diabetic or non-diabetic using the Axial-DeepLab network, and the attention layer was overlaid on the input image for interpretation.

RESULTS

Non-diabetic deep chambers were 90 %, 41 %, 34 %, and 39 % larger in area (26,954 ± 2428 µm2 vs 14,157 ± 1153 µm2), maximum (277 ± 13 µm vs 197 ± 8 µm) and minimum (140 ± 6 µm vs 104 ± 4 µm) diameter, and perimeter (405 ± 19 µm vs 291 ± 12 µm), respectively, than the superficial (p < 0.001). However, there was no significant difference in these parameters in diabetic specimens (area 18,695 ± 2576 µm2 vs 16627 ± 130 µm2, maximum diameter 221 ± 16 µm vs 210 ± 14 µm, minimum diameter 121 ± 8 µm vs 114 ± 7 µm, perimeter 341 ± 24 µm vs 320 ± 21 µm). Between diabetic and non-diabetic chambers, only the maximum diameter of the deep chambers differed (221 ± 16 µm vs 277 ± 13 µm). The attention network achieved 82 % accuracy on validation, but the attention resolution was too coarse to identify meaningful additional measurements.

CONCLUSIONS

Adipose chamber size differences may provide a basis for plantar soft tissue mechanical changes with diabetes. Attention networks are promising tools for classification, but additional care is required when designing networks for identifying novel features.

DATA AVAILABILITY

All images, analysis code, data, and/or other resources required to replicate this work are available from the corresponding author upon reasonable request.

Ultrasound of the plantar foot: a guide for the assessment of plantar intrinsic muscles

Plantar intrinsic muscles play a pivotal role in posture control and gait dynamics. They help maintain the longitudinal and transverse arches of the foot, and they regulate the degree and velocity of arch deformation during walking or running. Consequently, pathologies affecting the plantar intrinsic muscles (for instance, acquired and inherited neuropathies) lead to foot deformity, gait disorders, and painful syndromes. Intrinsic muscle malfunctioning is also associated with multifactorial overuse or degenerative conditions such as pes planus, hallux valgus, and plantar fasciitis. As the clinical examination of each intrinsic muscle is challenging, ultrasound is gaining a growing interest as an imaging tool to investigate the trophism of these muscular structures and the pattern of their alterations, and potentially to follow up on the effects of dedicated rehabilitation protocols. The ten plantar intrinsic muscles can be dived into three groups (medial, central and lateral) and four layers. Here, we propose a regional and landmark-based approach to the complex sonoanatomy of the plantar intrinsic muscles in order to facilitate the correct identification of each muscle from the superficial to the deepest layer. We also summarize the pathological ultrasound findings that can be encountered when scanning the plantar muscles, pointing out the patterns of alterations specific to certain conditions, such as plantar nerves mononeuropathies.

Effect of Partial Foot Amputation Level on Gait Independence in Patients With Chronic Lower Extremity Wounds: A Retrospective Analysis of a Japanese Multicenter Database

Partial foot amputation (PFA) is generally planned to minimize the amputation level; nonetheless, the effect of PFA levels on gait independence in amputees remains unclear. This study aimed to investigate the impact of PFA levels of the forefoot on gait independence in patients with chronic lower extremity (LE) wounds. This multicenter retrospective cohort study included 232 hospitalized Japanese patients treated and rehabilitated for chronic LE wounds. A multivariate analysis based on PFA levels was conducted for gait independence at discharge, with age and comorbidities as independent variables. Patients with Lisfranc amputation had significantly less independent gait than patients with more distal amputation and those without amputation (<22% vs >40%; P = .027; Fisher's exact test). Logistic regression analysis revealed that Lisfranc amputation (odds ratio [OR]: 0.257, P = .047), age (OR: 0.559, P = .043), and chronic limb-threatening ischemia (OR: 0.450, P = .010) were independent factors associated with gait independence. Additionally, the regression model confirmed discrimination performance using the C index (0.691, P < .001) with receiver operating characteristic analysis. In patients with chronic LE wounds undergoing PFA, Lisfranc amputation was negatively associated with gait independence.

Morphological and Mechanical Properties of Lower-Limb Muscles in Type 2 Diabetes: New Potential Imaging Indicators for Monitoring the Progress of DPN

The aim of this study was to explore changes in morphological and mechanical properties of lower-limb skeletal muscles in patients with diabetes with and without diabetic peripheral neuropathy (DPN) and seek to find a potential image indicator for monitoring the progress of DPN in patients with type 2 diabetes mellitus (T2DM). A total of 203 patients with T2DM, with and without DPN, were included in this study. Ultrasonography and ultrasound shear wave imaging (USWI) of the abductor hallux (AbH), tibialis anterior (TA), and peroneal longus (PER) muscles were performed for each subject, and the shear wave velocity (SWV) and cross-sectional area (CSA) of each AbH, TA, and PER were measured. The clinical factors influencing AbH_CSA and AbH_SWV were analyzed, and the risk factors for DPN complications were investigated. AbH_CSA and AbH_SWV in the T2DM group with DPN decreased significantly (P < 0.05), but no significant differences were found in the SWV and CSA of the TA and PER between the two groups. Toronto Clinical Scoring System (CSS) score and glycosylated hemoglobin (HbA1c) were independent predictors of AbH_CSA and AbH_SWV. As AbH_SWV and AbH_CSA decreased, Toronto CSS score and HbA1c increased and incidence of DPN increased significantly. In conclusion, the AbH muscle of T2DM patients with DPN became smaller and softer, while its morphological and mechanical properties were associated with the clinical indicators related to the progression of DPN. Thus, they could be potential imaging indicators for monitoring the progress of DPN in T2DM patients.