Biomechanical abnormalities and ulcers of the great toe in patients with diabetes

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.

Effects of walking speeds and durations on the plantar pressure gradient and pressure gradient angle

BACKGROUND

Walking exercise has been demonstrated to improve health in people with diabetes. However, it is largely unknown the influences of various walking intensities such as walking speeds and durations on dynamic plantar pressure distributions in non-diabetics and diabetics. Traditional methods ignoring time-series changes of plantar pressure patterns may not fully capture the effect of walking intensities on plantar tissues. The purpose of this study was to investigate the effect of various walking intensities on the dynamic plantar pressure distributions. In this study, we introduced the peak pressure gradient (PPG) and its dynamic patterns defined as the pressure gradient angle (PGA) to quantify dynamic changes of plantar pressure distributions during walking at various intensities.

METHODS

Twelve healthy participants (5 males and 7 females) were recruited in this study. The demographic data were: age, 27.1 ± 5.8 years; height, 1.7 ± 0.1 m; and weight, 63.5 ± 13.5 kg (mean ± standard deviation). An insole plantar pressure measurement system was used to measure plantar pressures during walking at three walking speeds (slow walking 1.8 mph, brisk walking 3.6 mph, and slow running 5.4 mph) for two durations (10 and 20 min). The gradient at a location is defined as the unique vector field in the two-dimensional Cartesian coordinate system with a Euclidean metric. PGA was calculated by quantifying the directional variation of the instantaneous peak gradient vector during stance phase of walking. PPG and PGA were calculated in the plantar regions of the first toe, first metatarsal head, second metatarsal head, and heel at higher risk for foot ulcers. Two-way ANOVA with Fisher's post-hoc analysis was used to examine the speed and duration factors on PPG and PGA.

RESULTS

The results showed that the walking speeds significantly affect PPG (P < 0.05) and PGA (P < 0.05), and the walking durations does not. No interaction between the walking duration and speed was observed. PPG in the first toe region after 5.4 mph for either 10 or 20 min was significantly higher than 1.8 mph. Meanwhile, after 3.6 mph for 20 min, PPG in the heel region was significantly higher than 1.8 mph. Results also indicate that PGA in the forefoot region after 3.6 mph for 20 min was significantly narrower than 1.8 mph.

CONCLUSIONS

Our findings indicate that people may walk at a slow speed at 1.8 mph for reducing PPG and preventing PGA concentrated over a small area compared to brisk walking at 3.6 mph and slow running at 5.4 mph.

Effects of wear and tear of therapeutic footwear in patients remission. A 5-year follow-up study

AIMS

To assesses the relationship between the wear and tear of therapeutic footwear (TF) and the risk of recurrence in diabetes remission patients.

METHODS

Remission patients (N = 115) participated in this 5-year prospective study in a specialized Diabetic Foot Unit between October 2016 and January 2022. Patients' TF was assessed in a three-month interval from Day 0 until ulcer recurrence was found. Primary outcome measure was based on the recurrent event in the forefoot.

RESULTS

A total of 82 patients (71.3%) renewed their TF, and 33 patients (28.7%) did not renew their TF during the follow-up period. Patients who failed to renew their TF group experienced more recurrent events (22 vs 14, p <.001, CI [0.04-0.259]) and minor amputations (11 vs 8, p =.002, CI [0.07-0.6]). Both groups showed different recurrence-free survival median times of 205.5 [Interquartile range (IQR) - 188-222] weeks and 89.9 [IQR - 53-126] weeks. Patients who did not renew their TF increased their risk of suffering from a recurrent event in the Cox regression model (p <.001, CI [0.03-0.38], Hazzard Ratio 0.147).

CONCLUSIONS

Patients who renewed their TF because of wear and tear experienced lower recurrences and minor amputations.

Diagnosis, imaging, and potential morbidities of the hallux interphalangeal joint os interphalangeus

Hallux pain is a common entity with a differential diagnoses including hallux valgus, hallux limitus/rigidus, and gout and specifically at the interphalangeal joint (IPJ), flexor hallucis longus (FHL) tenosynovitis, and joint arthrosis. An under-recognized source of pain is the os interphalangeus, an ossicle typically located at the plantar aspect of the hallucal interphalangeal joint. This ossicle is radiographically visible in its ossified form in 2-13% of individuals, but can also be present as an ossified or non-ossified nodule in patients. The os interphalangeus may be centrally or eccentrically located, and although originally believed to be a sesamoid bone in the FHL tendon, it is an ossicle located in the joint capsule of the IPJ and separated from the tendon by a bursa. When the ossicle is absent, the bursa is also absent and the tendon is attached to the joint capsule. Infrequently, the os may be located eccentrically under the first IPJ and reflect persistence of one of the distal phalanx. Rarely, the os interphalangeus may be dorsal to the IPJ. The os interphalangeus is best evaluated on radiographs, ultrasound, and MRI. Pain is a result of altered mechanics with arthrosis or frictional effects with bursitis, tenosynovitis, or intractable plantar keratosis (IPK). The ossicle may also displace into a dislocated IPJ, preventing reduction. The os interphalangeus may be centrally or eccentrically located, and although originally believed to be a sesamoid bone. This has been found within the plantar joint capsule of the distal hallucal interphalangeal joint and separated from the tendon by a bursa. Uncommonly, the location may be plantar eccentric and reflect persistence of one of the ossification centers of the distal phalanx. Although the ossicle can be imaged with standard AP and lateral radiographs in many cases, in those cases of unexplained pain with no radiographically visible ossicle, and the presence of friction blisters, intractable plantar keratosis (IPK), hyper-extension of the IPJ, hallux limitus/rigidus, or metatarsophalangeal joint (MTPJ) arthrodesis, an MRI or CT should be considered to identify a non-ossified fibrocartilaginous node. This is of particular concern in a patient with a history of underling diabetes mellitus or other metabolic disorders associated with diminished pedal sensation where neurotrophic changes place them most at risk for complications associated with excessive plantar pressure. Pain is a result of altered biomechanics with arthrosis, or frictional effects causing bursitis, tenosynovitis, or IPK. The ossicle may also displace into a dislocated IPJ, preventing reduction. In this article, we will describe the anatomy and imaging appearance of the common os interphalangeus variants and associated complications including frictional effects, arthrosis, and IPK and discuss conservative and surgical management of a symptomatic ossicle.

Clinical foot measurements as a proxy for plantar pressure testing in people with diabetes

Background

High plantar pressures are associated with increased foot ulcer risk in people with diabetes. Identification of high plantar pressures in people with diabetes is clinically challenging due to time and cost constraints of plantar pressure testing. Factors affecting foot biomechanics, including reduced joint range of motion and foot deformity, are implicated in the development of high plantar pressures and may provide a method to clinically identify those at risk of pressure related complications. The aim of this study was to investigate the contribution of joint range of motion and foot deformity measures on plantar pressures in a community dwelling group with diabetes.

Methods

Barefoot (Tekscan HR Mat™) and in-shoe (Novel Pedar-X®) plantar pressure variables, weight bearing ankle dorsiflexion, hallux range of motion, lesser toe deformities and hallux abductus (HAV) scale were assessed in 136 adults with diabetes (52.2% male; mean age 68.4 years). Multivariate multiple linear regression was used to assess the effect of the four biomechanical factors plus neuropathy and body mass index on plantar pressure variables. Non-parametric bootstrapping was employed to determine the difference in plantar pressure variables for participants with two or more foot biomechanical pathologies compared to those with less than two pathologies.

Results

Almost one third (32%) of the cohort had two or more foot biomechanical pathologies. Participants with two or more foot biomechanical pathologies displayed significant increases in all barefoot plantar pressure regions (except forefoot), compared to those with less than two pathologies. No significant changes were found for the in-shoe plantar pressure variables. The regression model explains between 9.9% (95%CI: 8.4 to 11.4%) and 29.6% (95% CI: 28.2 to 31%), and between 2.5% (1.0 to 4.0%) and 43.8% (95% CI: 42.5–44.9%), of the variance in the barefoot and in-shoe plantar pressure variables respectively.

Conclusions

Participants presenting with two or more factors affecting foot biomechanics displayed higher peak pressures and pressure time integrals in all foot regions compared to those with less than two factors. The tests used in this study could help clinicians detect elevated plantar pressures in people with diabetes and present an opportunity for early preventative interventions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13047-021-00494-4.

Conversion of First Metatarsophalangeal Joint Arthrodesis to Interpositional Arthroplasty With Acellular Dermal Matrix for First Ray Ulceration: A Case Report

The purpose of this study is to report the outcome of the conversion of a first metatarsophalangeal (MTP) joint arthrodesis to an interpositional arthroplasty with an acellular dermal matrix for a chronic nonhealing first ray wound. To our knowledge, this is the first case report converting a first ray arthrodesis to an interpositional arthroplasty to heal a chronic ulceration. A 78-year-old female developed a chronic neuropathic ulceration under the first metatarsal head and hallux after a first MTP joint arthrodesis. The patient failed local wound care and underwent gastrocnemius recession, hallux interphalangeal joint fusion, and an interpositional arthroplasty with the use of an acellular dermal matrix. Bone tunnels were placed proximal to the metatarsal neck, where absorbable sutures affixed to the dermal matrix were passed from plantar to dorsal, and the graft was secured to the reamed metatarsal head and associated capsule. Postoperative radiographs revealed improved alignment of the first MTP joint. Complete reepithelialization of the plantar ulceration occurred within 2 weeks postoperatively. At the 16-month follow-up, the patient was ambulating without restriction and continued to be free of first ray ulceration and infection. This case study details the use of an acellular dermal matrix in an interpositional arthroplasty to offload a chronic nonhealing ulceration secondary to elevated first ray pressure associated with first MTP joint arthrodesis. The goal of this treatment is to reduce pain, heal the ulceration, and prevent its recurrence.

Diabetic foot off loading and ulcer remission: Exploring surgical off-loading

INTRODUCTION

Diabetic peripheral neuropathy leads to foot deformity, soft tissues damage, and gait imbalance, all of which can increase the mechanical stress imposed on the foot and give rise to Charcot neuroarthropathy. The current International Working Group of the Diabetic Foot International Guidelines on offloading focus on managing neuropathic foot ulcers related to pressure: only 2 of their 9 recommendations deal with surgical interventions. We assess the role of surgical techniques in off-loading to heal and possibly prevent diabetic foot ulceration.

METHODS

We systematically analysed published data from January 2000 to November 2020 to assess methods of surgical offloading and associated outcomes for the surgical reconstruction. We tried to identify healing, remission-rates, return to ambulation, complications and limitations.

RESULTS

Five discrete categories of surgical offloading are used in recalcitrant ulcers: 1. Lesser toe tenotomies; 2. Metatarsal head resection ± Achilles tendon release; 3. Hallux procedures; 4. Bony off-loading procedures in the form of exostectomy; and 5. Complex surgical foot reconstruction. Adjuvant modalities including surgically placed antibiotic delivery systems show promise, but further studies are required to clarify their role and effect on systemic antibiotic requirements.

CONCLUSIONS AND IMPLICATIONS

Surgery is important to mechanically stabilise and harmonise the foot for long term off-loading and foot-protection. Surgery should not be reserved for recalcitrant cases only, but extended to ulcer prevention and remission. Further comparative studies will benefit surgical decision making to avoid recurrence and define time point when surgical off-loading could protect against irretrievable tissue loss/re-ulceration.

The Biomechanics of Diabetes Mellitus and Limb Preservation

Biomechanical changes to the lower extremity in patients with diabetes mellitus are typically greatest with peripheral neuropathy, although peripheral arterial disease also impacts limb function. Changes to anatomic structures can impact daily function. These static changes, coupled with kinetic and kinematic changes of gait, lead to increased vertical and shear ground reactive forces, resulting in ulcerations. Unsteadiness secondary to diminished postural stability and increased sway increase fall risk. These clinical challenges and exacerbation of foot position and dynamic changes associated with limb salvage procedures, amputations, and prostheses are necessary and can impact daily function, independence, quality of life, and mortality.

Healing ulcers and preventing their recurrences in the diabetic foot

Fifteen percent of people with diabetes develop an ulcer in the course of their lifetime. Eighty-five percent of the major amputations in diabetes mellitus are preceded by an ulcer. Management of ulcers and preventing their recurrence is important for the quality of life of the individual and reducing the cost of care of treatment. The main causative factors of ulceration are neuropathy, vasculopathy and limited joint mobility. Altered bio-mechanics due to the deformities secondary to neuropathy and limited joint mobility leads to focal points of increased pressure, which compromises circulation leading to ulcers. Ulcer management must not only address the healing of ulcers but also should correct the altered bio-mechanics to reduce the focal pressure points and prevent recurrence. An analysis of 700 patients presenting with foot problems to the Diabetic Clinic of Ganga Hospital led to the stratification of these patients into four classes of incremental severity. Class 1 – the foot at risk, Class 2 – superficial ulcers without infection, Class 3 – the crippled foot and Class 4 – the critical foot. Almost 77.5% presented in either Class 3 or 4 with complicated foot ulcers requiring major reconstruction or amputation. Class 1 foot can be managed conservatively with foot care and appropriate foot wear. Class 2 in addition to measures for ulcer healing would need surgery to correct the altered bio-mechanics to prevent the recurrence. The procedures called surgical offloading would depend on the site of the ulcer and would need an in-depth clinical study of the foot. Class 3 would need major reconstructive procedures and Class 4 would need amputation since it may be life-threatening. As clinicians, our main efforts must be focused towards identifying patients in Class 1 and offer advice on foot care and Class 2 where appropriate surgical offloading procedure would help preserve the foot.

Clinical efficacy of therapeutic footwear with a rigid rocker sole in the prevention of recurrence in patients with diabetes mellitus and diabetic polineuropathy: A randomized clinical trial

Background

Therapeutic footwear becomes the first treatment line in the prevention of diabetic foot ulcer and future complications of diabetes. Previous studies and the International Working Group on the Diabetic Foot have described therapeutic footwear as a protective factor to reduce the risk of re-ulceration. In this study, we aimed to analyze the efficacy of a rigid rocker sole to reduce the recurrence rate of plantar ulcers in patients with diabetic foot.

Methods

Between June 2016 and December 2017, we conducted a randomized controlled trial in a specialized diabetic foot unit.

Participants and intervention

Fifty-one patients with diabetic neuropathy who had a recently healed plantar ulcer were randomized consecutively into the following two groups: therapeutic footwear with semi-rigid sole (control) or therapeutic footwear with a rigid rocker sole (experimental). All patients included in the study were followed up for 6 months (one visit each 30 ± 2 days) or until the development of a recurrence event.

Main outcome and measure

Primary outcome measure was recurrence of ulcers in the plantar aspect of the foot.

Findings

A total of 51 patients were randomized to the control and experimental groups. The median follow-up time was 26 [IQR—4.4—26.1] weeks for both groups. On an intention-to-treat basis, 16 (64%) and 6 (23%) patients in the control and experimental groups had ulcer recurrence, respectively. Among the group with >60% adherence to therapeutic footwear, multivariate analysis showed that the rigid rocker sole improved ulcer recurrence-free survival time in diabetes patients with polyneuropathy and DFU history (P = 0.019; 95% confidence interval, 0.086–0.807; hazard ratio, 0.263).

Conclusions

We recommend the use of therapeutic footwear with a rigid rocker sole in patients with diabetes with polyneuropathy and history of diabetic foot ulcer to reduce the risk of plantar ulcer recurrence.

Trial registration

ClinicalTrials.gov NCT02995863.

Current concepts in curative surgery for diabetic forefoot ulcers

Forefoot ulcerations in patients with diabetes are quite common. Underlying mechanical deformities of the foot in combination with neuropathy are the most important risk factors for ulcer development and adequate offloading is the mainstay of management. Most ulcers heal with local wound care, adequate blood supply, and pressure relief. If a foot deformity cannot be accommodated, ulcers will not heal or may recur. In this case, surgical correction of deformity is necessary. This paper reviews the most common procedures supported by medical evidence to heal neuropathic forefoot ulcers.

Predictors of Diabetic Foot Reulceration beneath the Hallux

AIMS

To evaluate the factors that predict reulceration beneath the hallux in people with a history of diabetic foot ulceration.

METHODS

A prospective study conducted between January 2012 and December 2014 was performed in a diabetic foot unit to assess the risk factors associated with hallux reulceration. Sixty patients with diabetic neuropathy and a history of previous ulcer were consecutively included. Sociodemographic factors and comorbidities plus the biomechanical and radiographic factors were obtained. Follow-up on participants was conducted every month, and they wore offloading therapeutic footwear and custom-made insoles. Hallux reulceration during the follow-up period was assessed as the main outcome measure in the study.

RESULTS

Patients were followed up during 29 (14.2-64.4) months. Twenty-nine patients (52%) developed a new ulceration: 9 patients (31%) in the hallux and 20 (69%) in other locations. Functional hallux limitus (p = 0.005, 95% CI (2.097-73.128), HR 12.384) and increased body mass index (p = 0.044, 95% CI (1.003-1.272), HR 1.129) were associated with the hallux ulceration-free survival time in the multivariate Cox model.

CONCLUSIONS

Obesity and the presence of functional hallux limitus increase the probability of developing hallux reulceration in patients with diabetic neuropathy and a history of ulcers.

Prevalence of ankle equinus and correlation with foot plantar pressures in people with diabetes

BACKGROUND

An association between equinus and plantar pressure may be important for people with diabetes, as elevated plantar pressure has been linked with foot ulcer development. To determine the prevalence of equinus in community dwelling people with diabetes and to examine any association between presence of equinus and forefoot plantar pressures.

METHODS

Barefoot (Tekscan HR Mat™) and in-shoe (Novel Pedar-X®) plantar pressure variables, non-weight bearing ankle range of motion and neuropathy status were assessed in 136 adults with diabetes (52.2% male; 47.8% with neuropathy; mean (standard deviation) age and diabetes duration: 68.4 (11.5) and 14.6 (11.1) years respectively).

FINDINGS

Equinus, when measured as ≤5° dorsiflexion, was present in 66.9% of the cohort. There was a significant correlation between an equinus and barefoot (r = 0.247, p = 0.004) and in-shoe forefoot pressure time integrals (r = 0.214, p = 0.012) and in-shoe forefoot alternate pressure time integrals (r = 0.246, p = 0.004). Significantly more males (p < 0.01) and people with neuropathy (p = 0.02) or higher glycated haemoglobin levels (p < 0.01) presented with an equinus.

INTERPRETATION

Community dwelling adults with diabetes have a high rate of ankle equinus which is associated with increased forefoot pressure time integrals and a two-fold increased risk of high in-shoe peak pressures. Clinical assessment of an ankle equinus may be a useful screening tool to identify adults at increased risk of diabetic foot complications.

Distal Syme Hallux Amputation for Tip of Toe Wounds and Gangrene Complicated by Osteomyelitis of the Distal Phalanx: Surgical Technique and Outcome in Consecutive Cases

Distal hallux gangrene and neuropathic ulceration associated with digit deformity frequently result in osteomyelitis of the distal phalanx. Ideal treatment would involve limited resection to preserve function. We describe our surgical technique and retrospective results for distal Syme hallux amputation with plantar flap closure. An institutional review board-approved review was conducted on cases performed over 8 years. A total of 15 consecutive patients (16 digits) with hallux soft tissue loss who had undergone distal Syme hallux amputation were included. In each case, initial resection removed the distal hallux wound, nail bed, and distal phalanx. The proximal phalanx tip was remodeled, allowing margin biopsy and reduction of prominence. Of the 16 digits, 5 (31.3%) had hammertoe deformity and 1 (6.3%) was excessively long. Positive probe-to-bone status was identified in 8 of the 16 digits (50.0%). All 8 ulcers (100.0%) that probed to bone had histologic or culture results consistent with distal phalanx osteomyelitis. A proximal margin biopsy was taken in 12 of 16 digits (75.0%), and proximal phalanx osteomyelitis was observed in 4 of 12 proximal margin biopsies (33.3%). Two digits (12.5%) failed to heal. Three digits (18.8%) required a more proximal amputation, and the remaining 13 (81.3%) were found to be well-healed and functional at the final follow-up examination. The mean follow-up period was 27.6 (range 8 to 97) months. We have found distal Syme hallux amputation to be an effective treatment when used judiciously for distal hallux gangrene and osteomyelitis associated with neuropathic ulceration. This procedure permits bone biopsy for early diagnosis, confirmation of clean margins, removal of nonviable tissue and the abnormal toenail, and some deformity correction.

Weight bearing versus non-weight bearing ankle dorsiflexion measurement in people with diabetes: a cross sectional study

Background

Accurate measurement of ankle dorsiflexion is important in both research and clinical practice as restricted motion has been associated with many foot pathologies and increased risk of ulcer in people with diabetes. This study aimed to determine the level of association between non-weight bearing versus weight bearing ankle dorsiflexion in adults with and without diabetes, and to evaluate the reliability of the measurement tools.

Methods

One hundred and thirty-six adults with diabetes and 30 adults without diabetes underwent ankle dorsiflexion measurement non-weight bearing, using a modified Lidcombe template, and weight bearing, using a Lunge test. Pearson product-moment correlation coefficients, intraclass correlation coefficients (ICCs) with 95% confidence intervals, standard error of measurement and minimal detectable change were determined.

Results

There was a moderate correlation (r = 0.62–0.67) between weight and non-weight bearing tests in the non-diabetes group, and a negligible correlation in the diabetes group(r = 0.004–0.007). Intratester reliability was excellent in both groups for the modified Lidcombe template (ICC = 0.89–0.94) and a Lunge test (ICC = 0.83–0.89). Intertester reliability was also excellent in both groups for the Lidcombe template (ICC = 0.91) and a Lunge test (ICC = 0.88–0.93).

Conclusions

We found the modified Lidcombe template and a Lunge test to be reliable tests to measure non-weight bearing and weight bearing ankle dorsiflexion in adults with and without diabetes. While both methods are reliable, further definition of weight bearing ankle dorsiflexion normative ranges may be more relevant for clinical practice.

Association between ankle equinus and plantar pressures in people with diabetes. A systematic review and meta-analysis

BACKGROUND

Diabetes is one of the most common chronic diseases in the world and is associated with a life-time risk of foot ulcer of 12-25%. Diabetes related restriction in ankle joint range of dorsiflexion is proposed to contribute to elevated plantar pressures implicated in the development of foot ulcers.

METHODS

A systematic search of EBSCO Megafile Premier (containing MEDLINE, CINAHL, SPORTSdiscus and Academic Search Complete) and The Cochrane Library was conducted to 23rd November 2016. Two authors independently reviewed and selected relevant studies. Meta-analysis of study data were conducted where possible.

FINDINGS

Fifteen studies met the inclusion criteria. Three studies were eligible to be included in the meta-analysis which found that equinus has a significant, but small, effect on increased plantar pressures (ES=0.26, CI 95% 0.11 to 0.41, p=0.001). Of the remaining studies, eight found evidence of an association between limited ankle dorsiflexion and increased plantar pressures while four studies found no relationship.

INTERPRETATION

Limited ankle joint dorsiflexion may be an important factor in elevating plantar pressures, independent of neuropathy. Limited ankle dorsiflexion and increased plantar pressures were found in all the studies where the sample population had a history of neuropathic foot ulceration. In contrast, the same association was not found in those studies where the population had neuropathy and no history of foot ulcer. Routine screening for limited ankle dorsiflexion range of motion in the diabetic population would allow for early provision of conservative treatment options to reduce plantar pressures and lessen ulcer risk.

Influence of Hallux Rigidus on Reamputation in Patients With Diabetes Mellitus After Partial Hallux Amputation

Diabetic foot ulceration of the plantar hallux is a challenging condition and can require partial hallux amputation when complicated by infection. Lower extremity biomechanics play an important role in the development of hallux ulcers, and hallux rigidus (HR) could influence the outcomes after partial hallux amputation. We hypothesized that radiographic evidence of HR in patients with diabetes would be associated with greater ulcer recurrence and reamputation rates after partial hallux amputation. We performed a retrospective review of all patients with diabetes who had undergone a partial hallux amputation from January 2005 to December 2012. The subjects were divided into 2 cohorts according to the presence or absence of HR identified on preoperative radiographs. Baseline characteristics and outcomes were compared using a 2-sample Student's t test for continuous variables, and categorical variables were compared using the chi-square test for homogeneity and Fisher's exact test. A total of 52 patients were included, with 16 (31%) positive for radiographic evidence of HR at partial hallux amputation. Differences in the patient demographics and comorbidities were not significant between 2 cohorts with and without HR or reamputation. Reamputation was required in 5 subjects (31%) with HR and 2 (6%) without HR (p = .023). The average follow-up duration was 126 ± 89 weeks. Our results have demonstrated that the reamputation rate after partial hallux amputation is significantly greater in patients with than in those without radiographic evidence of HR. Surgeons should evaluate patients for HR when planning partial hallux amputation and use adjuvant methods of offloading when HR is evident to prevent recurrent ulceration and reamputation.

The role of surgical off-loading to prevent recurrent ulcerations

Foot ulcerations in patients with diabetes are common. Most ulcers heal with conservative treatment, but recurrence is common. The pathway of ulcer development includes neuropathy, deformity, and trauma. The first attempt to avoid recurrence is by the use of shoes and insoles. When shoes and insoles fail, surgical correction of deformity leading to the ulcer can be attempted. This article reviews the most common procedures performed to heal ulcers or avoid recurrence.

Unilobed Rotational Flap for Plantar Hallux Interphalangeal Joint Ulceration Complicated by Osteomyelitis

Diabetes-related neuropathic ulcers located at the plantar aspect of the hallux interphalangeal joint are often chronic or recurrent and frequently become complicated by osteomyelitis. Once infected, treatment will typically involve hallux amputation. Although intended as a definitive procedure, amputation of the first toe is not desirable from a cosmetic or functional standpoint and often leads to transfer ulcers at adjacent locations of the foot. Reconstructive wound surgery, combined with limited bone resection, is possible if the infection is caught early before the local tissue and bone have become necrotic. In addition to neuropathy, biomechanical issues, including ankle equinus, hallux limitus, hallux extensus, and hallux valgus, predispose patients with diabetes mellitus to developing plantar hallux ulcers. We commonly employ a proximal based unilobed plantar rotational flap combined with hallux interphalangeal joint arthroplasty as an alternative to hallux amputation. We present a typical case with long-term follow-up to highlight our flap protocol, including patient selection criteria, flap design, surgical technique, bone resection and biopsy pearls, staging timeline, and a typical postoperative course. Periodic follow-up during the next 72 months for unrelated conditions allowed long-term monitoring with no recurrence of osteomyelitis or subsequent amputation. The foot remained ulcer free 6 years later. The benefits of this surgical approach include complete excision of the ulcer, adequate exposure for bone resection, early bone biopsy before the spread of infection or necrosis of local tissue, flap coverage with viable soft tissue, and partial offloading of mechanical pressure at the plantar interphalangeal joint.

The best way to reduce reulcerations: if you understand biomechanics of the diabetic foot, you can do it

Foot ulcer recurrence is still an unresolved issue. Although several therapies have been described for preventing foot ulcers, the rates of reulcerations are very high. Footwear and insoles have been recommended as effective therapies that prevent the development of new ulcers; however, the majority of studies have analyzed their effects in terms of reducing peak plantar pressure rather than ulcer relapse. Knowledge of biomechanical considerations is low, in general, in the team approach to diabetic foot because heterogeneous professionals having competence in recurrence prevention are involved. Assessment of biomechanical alterations define a foot type position; examining foot structure and recording plantar pressure could help in appropriate insole and footwear prescription and design. Patient education and compliance should be taken into consideration for better therapy success. When patients suffer from rigid deformities or have undergone an amputation, surgical offloading should be considered as an alternative.

Hallux abductus interphalangeus in normal feet, early-stage hallux limitus, and hallux valgus

BACKGROUND

Excessive deviation of the distal phalanx in abduction frequently occurs in advanced stages of hallux rigidus but not in hallux valgus. Therefore, theoretically there should be no significant differences in the hallux interphalangeal angle (HIPA) between individuals with normal feet, those with hallux valgus, and those with mild hallux limitus. The objective of the present study was thus to determine if significant differences in HIPA exist in the early stages of hallux valgus or hallux limitus deformities.

METHODS

The hallux interphalangeal angle was measured in three groups of participants: a control group with normal feet (45 participants), a hallux valgus group (49 participants), and a hallux limitus group (48 participants). Both of the pathologies were at an early stage. A dorsoplantar radiograph under weightbearing conditions was taken for each individual, and measurements (HIPA and hallux abductus angle [HAA]) were taken using AutoCAD (Autodesk Inc, San Rafael, California) software. Intergroup comparisons of HIPA, and correlations between HIPA, HAA, and hallux dorsiflexion were calculated.

RESULTS

The comparisons revealed no significant differences in the values of HIPA between any of the groups (15.2 ± 5.9 degrees in the control group, 15.5 ± 3.9 degrees in the hallux valgus group, and 16.15 ± 4.3 in the hallux limitus group; P  =  0.634). The Pearson correlation coefficients in particular showed no correlation between hallux dorsiflexion, HAA, and HIPA.

CONCLUSIONS

For the study participants, there were similar deviations of the distal phalanx of the hallux with respect to the proximal phalanx in normal feet and in feet with the early stages of the hallux limitus and hallux valgus deformities.

Preventing the first or recurrent ulcers

Prevention is overlooked and underused, even in very high-risk patients. Prevention is best achieved within a multispecialty group of providers that have a common objective. Ideally, the team approach should include educators; physical therapists; nurses; internist; pedorthists; and vascular, orthopedic, and podiatric surgeons. The basic elements involve education, foot examination, risk classification, therapeutic shoes and insoles, and regular foot care. High-risk patients need additional assessment for vascular disease and intensive disease management, and corrective vascular and foot surgery when necessary. Basic interventions can reduce the incidence of foot ulcers by more than 50%.

Reduction of peak plantar pressure in people with diabetes-related peripheral neuropathy: an evaluation of the DH Pressure Relief Shoe™

Background

Offloading plantar pressure is a key strategy for the prevention or healing of neuropathic plantar ulcers in diabetes. Non-removable walking casts, such as total contact casts, are currently considered the gold-standard for offloading this type of wound. However, alternative methods for offloading that are more cost effective and easier to use are continually being sought. The aim of this study was to evaluate the capacity of the DH Pressure Relief Shoe™ to offload high pressure areas under the neuropathic foot in diabetes.

Methods

A within-subjects, repeated measures design was used. Sixteen participants with diabetic peripheral neuropathy were recruited and three footwear conditions were evaluated in a randomised order: a canvas shoe (the control), the participants’ own standard shoe, and the DH Pressure Relief Shoe™. The primary outcome was peak plantar pressure, measured using the pedar-X® mobile in-shoe system between the three conditions.

Results

Data analysis was conducted on 14 out of the 16 participants because two participants could not complete data collection. The mean peak pressure values in kPa (±SD) for each condition were: control shoe 315.9 (±140.7), participants’ standard shoe 273.0 (±127.1) and DH Pressure Relief Shoe™ 155.4 (±89.9). There was a statistically significant difference in peak plantar pressure between the DH Pressure Relief Shoe™ compared to both the control shoe (p = 0.002) and participants’ standard shoe (p = 0.001). The DH Pressure Relief Shoe™ decreased plantar pressures by 51% compared to the control shoe and by 43% compared to participants’ standard shoe. Importantly, for a couple of study participants, the DH Pressure Relief Shoe™ appeared unsuitable for day-to-day wearing.

Conclusions

The DH Pressure Relief Shoe™ reduced plantar pressures more than the other two shoe conditions. The DH Pressure Relief Shoe™ may be a useful alternative to current offloading modalities used in clinical management of diabetic foot ulceration. However, clinical trials are needed to test their effectiveness for ulcer healing and to ensure they are useable and safe for patients in everyday activities.

Prevalence of equinus in diabetic versus nondiabetic patients

BACKGROUND

There are no conclusive data to support the contention that diabetic patients have an increased frequency of ankle equinus compared with their nondiabetic counterparts. Additionally, a presumed contributing cause of foot ulceration is ankle joint equinus. Therefore, we sought to determine whether persons with diabetes have a higher prevalence of ankle joint equinus than do nondiabetic persons.

METHODS

A prospective pilot survey of 102 outpatients (43 diabetic and 59 nondiabetic) was conducted. Demographic and historical data were obtained. Each patient underwent a standard lower-extremity examination, including the use of a biplane goniometer to measure ankle joint range of motion.

RESULTS

Equinus, defined as ankle dorsiflexion measured at 0° or less, was found in 24.5% of the overall population. In the diabetes cohort, 16 of 43 patients (37.2%) were affected compared with 9 of 59 nondiabetic participants (15.3%) (P = .011). There was a threefold risk of equinus in the diabetic population (odds ratio [OR], 3.3; 95% confidence interval [CI], 1.28-8.44; P < .013). The equinus group had a history of ulceration in 52.0% compared with 20.8% of the nonequinus group (P = .003). Equinus, therefore, imparted a fourfold risk of ulceration (OR, 4.13; 95% CI, 1.58-10.77; P < .004). We also found a 2.8 times risk of equinus in patients with peripheral neuropathy (OR, 2.8; 95% CI, 1.11-7.09; P < .029).

CONCLUSIONS

Equinus may be more prevalent in diabetic patients than previously reported. Although we cannot prove causality, we found a significant association between equinus and ulceration.

In-shoe Plantar Pressure Distribution in Nonneuropathic Type 2 Diabetic Patients in Singapore

BACKGROUND

We sought to establish the in-shoe plantar pressure distribution during normal level walking in type 2 diabetic patients of Chinese, Indian, and Malay descent without clinical evidence of peripheral neuropathy.

METHODS

Thirty-five patients with type 2 diabetes mellitus without loss of tactile sensation and foot deformities and 38 nondiabetic individuals in a control group had in-shoe plantar pressures collected. Maximum peak pressure and peak pressure-time integral of each foot were analyzed as separate variables and were masked into 13 areas. Differences in pressure variables were assessed by analysis of covariance, adjusting for relevant covariates at the 95% confidence interval.

RESULTS

No significant differences were noted in maximum peak pressures after adjusting for sex, race, age, height, and body mass. However, patients with diabetes mellitus had significantly higher mean ± SD pressure-time integrals at the right whole foot (309.50 ± 144.17 kPa versus 224.06 ± 141.70 kPa, P < .05) and first metatarsal (198.65 ± 138.27 kPa versus 121.54 ± 135.91 kPa, P < .05) masked areas than did those in the control group after adjustment.

CONCLUSIONS

Patients without clinical observable signs of foot deformity (implying absence of motor neuropathy) and sensory neuropathy had similar in-shoe maximum peak pressures as controls. This finding supported the notion that either component of neuropathy needs to be present before plantar pressures are elevated. Patients with diabetes mellitus demonstrated greater pressure-time integrals, implying that this variable might be the first clinical sign observable even before peripheral neuropathy could be tested.

Foot biomechanics in patients with diabetes mellitus: doubts regarding the relationship between neuropathy, foot motion, and deformities

BACKGROUND

We sought to identify the biomechanical characteristics of the feet of patients with diabetes mellitus and the interrelationship with diabetic neuropathy by determining the range of joint mobility and the presence and locations of calluses and foot deformities.

METHODS

This observational comparative study involved 281 patients with diabetes mellitus who underwent neurologic and vascular examinations. Joint mobility studies were performed, and deformities and hyperkeratosis locations were assessed.

RESULTS

No substantial differences were found between patients with and without neuropathy in joint mobility range. Neuropathy was seen as a risk factor only in the passive range of motion of the first metatarsophalangeal joint (mean ± SD: 57.2° ± 19.5° versus 50.3° ± 22.5°, P = .008). Mean ± SD ankle joint mobility values were similar in both groups (83.0° ± 5.2° versus 82.8° ± 9.3°, P = .826). Patients without neuropathy had a higher rate of foot deformities such as hallux abductus valgus and hammer toes. There was also a higher presence of calluses in patients without neuropathy (82.8% versus 72.6%; P = .039).

CONCLUSIONS

Diabetic neuropathy was not related to limited joint mobility and the presence of calluses. Patients with neuropathy did not show a higher risk of any of the deformities examined. These findings suggest that the etiology of biomechanical alterations in diabetic people is complex and may involve several anatomically and pathologically predisposing factors.

Hallux ulceration in diabetic patients

We undertook a prospective cohort study to assess risk factors associated with hallux ulceration, and to determine the incidence of healing or amputation, in consecutive patients with diabetes mellitus who were treated over the observation period extending from September 2004 to March 2005, at the Jabir Abu Eliz Diabetic Centre, Khartoum City, Sudan. There were 122 diabetic patients in the cohort (92 males and 30 females) with an overall mean age of 58 +/- 9 years. Fifty-three percent of patients had complete healing within 8 weeks and 43% healed within 20 weeks. The overall mean time to healing was 16 +/- 8 weeks. In 32 (26.2%) patients, osteomyelitic bone was removed, leaving a healed and boneless hallux. The hallux was amputated in 17 (13.9%) patients; in 2 (1.6%) patients it was followed by forefoot amputation and in 7 (5.7%) patients by below-the-knee amputation. In 90 (73.8%) patients the initial lesion was a blister. In conclusion, hallux ulceration is common in patients with diabetes mellitus and is usually preceded by a blister. Neuropathy, foot deformity, and wearing new shoes are common causative factors; and ischemia, osteomyelitis, any form of wound infection, and the size of the ulcer are main outcome determinants. Complete healing occurred in 103 (85%) of diabetic patients with a hallux ulcer. Vascular intervention is important relative to limb salvage when ischemia is the main cause of the ulcer.

Neuropathic toe ulcers treated with toe flexor tenotomies

BACKGROUND

Foot ulcers are common causes of hospital admissions for infection and amputation in patients with neuropathy. This retrospective study evaluates the results of treating plantar neuropathic toe ulcers with percutaneous flexor tenotomy.

METHODS

From 1996 to 2003, 28 toe ulcers in 18 patients were treated with tenotomy of the toe flexors.

RESULTS

Fourteen of 18 patients had diabetic neuropathy. No patients were lost to followup. Average followup for the 28 ulcers was 36 (range 20 to 65) months. All ulcers healed. None of the 11 lesser toe ulcers recurred. Three of 17 first toe ulcers recurred but two that had repeat tenotomy healed and did not recur. There were no toe amputations, infections, or other complications of tenotomy. One patient had unrelated transtibial amputation.

CONCLUSIONS

No long-term results of treating toe ulcers with toe flexor tenotomy by other authors have been found. Toe flexor tenotomies appear to be effective and safe treatment for neuropathic toe ulcers.

Evaluation of atrophy of foot muscles in diabetic neuropathy – A comparative study of nerve conduction studies and ultrasonography

OBJECTIVE

To evaluate the relation between the findings at nerve conduction studies and the size of small foot muscles determined by ultrasonography.

METHODS

In 26 diabetic patients the size of the extensor digitorum brevis muscle (EDB) and of the muscles between the first and second metatarsal bone (MIL) was determined. Motor nerve conduction studies of the peroneal and tibial nerves were performed with determination of the amplitudes of the CMAPs and of the nerve conduction velocities (NCV). Further, a standardised clinical examination was performed providing a neurological impairment score.

RESULTS

Seventeen patients fulfilled the criteria for diabetic neuropathy. The cross-sectional area of the EDB muscle and the thickness of the MIL muscle were 116 +/- 65 mm2 and 29.6 +/- 8.2 mm, respectively. Close relations were established between muscle size and the amplitude of the CMAP of the peroneal (r=0.77, p<0.001) and of the tibial nerve (r=0.70, p<0.01). Further there were close relations between the muscle size and the NCV of the peroneal (r=0.62, p<0.01) and of the tibial nerve (r=0.71, p<0.001).

CONCLUSIONS

The amplitude of the CMAP of the peroneal and of the tibial nerves is closely related to the size of the small foot muscles as determined by ultrasonography.

SIGNIFICANCE

In diabetic patients motor nerve conduction studies can reliably determine the size of small foot muscles.

Weight-bearing passive dorsiflexion of the hallux in standing is not related to hallux dorsiflexion during walking

STUDY DESIGN

Case control study.

OBJECTIVE

To explore the validity of the assumptions underpinning the Hubscher maneuver of hallux dorsiflexion in relaxed standing, by comparing the relationship between static and dynamic first metatarsophalangeal (MTP) joint motions in groups differentiated by normal and abnormal clinical test findings.

BACKGROUND

Limitation of motion at the first MTP joint during gait may be due to either structural or functional factors. Functional hallux limitus (FHL) has been proposed as a term to describe the situation in which the first MTP joint shows no limitation when non-weight bearing, but shows limited dorsiflexion during gait. One clinical test of first MTP joint limitation during standing (the Hubscher maneuver or Jack's test) has become widely used in physical therapy, orthopedic, and podiatric assessments, supposedly to assess for the presence of hallux limitations during gait. The utility of the test is based on an assumption that restriction during the static maneuver is predictive of functional limitation at this joint during gait. Despite a lack of evidence for the validity of such an assumption, the outcome of the static test is often used to infer risk of overuse injury or as an outcome for functional therapy. This paper examines the validity of the assumptions supporting this widely used static test.

METHODS AND MEASURES

First-MTP-joint motion was assessed using an electromagnetic motion tracking system in cases (n = 15) demonstrating clinically limited passive hallux dorsiflexion in relaxed standing, and in 15 controls matched for age and gender and demonstrating a clinically normal Hubscher maneuver. Maximum hallux dorsiflexion was measured with the subject non-weight bearing (seated), during relaxed standing, and during normal walking.

RESULTS

Hallux dorsiflexion was similar in cases and controls when motions were measured non-weight bearing (cases mean +/- SD, 55.0 degrees +/- 11.0 degrees; controls mean + SD, 55.0 degrees +/- 10.7 degrees), confirming the absence of structural joint change. In relaxed standing, maximum dorsiflexion was 50% less in cases (mean +/- SD, 19.0 degrees +/- 8.9 degrees) than in the controls (mean +/- SD, 39.4 degrees +/- 6.1 degrees; P < .001), supporting the initial test outcome and confirming the visual test observation of static functional limitation in the case group. During gait, however, cases (mean +/- SD, 36.4 degrees +/- 9.1 degrees), and controls (mean +/- SD, 36.9 degrees +/- 7.9 degrees) demonstrated comparable maximum dorsiflexion (P = .902). There was no significant relationship between static and dynamic first MTP joint motions (r = 0.186, P = .325).

CONCLUSION

The clinical test of limited passive hallux dorsiflexion in stance is a valid test only of hallux dorsiflexion available during relaxed standing. There is no association between maximum dorsiflexion observed during a static weight-bearing examination and that occurring at the same joint during walking.