Functionally Optimized Orthoses for Early Rheumatoid Arthritis Foot Disease: A Study of Mechanisms and Patient Experience

Developing a core outcome set for foot and ankle disorders in rheumatic and musculoskeletal diseases: A scoping review and report from the OMERACT 2022 foot and ankle special interest group session

OBJECTIVES

Foot and ankle involvement is common in rheumatic and musculoskeletal diseases, yet high-quality evidence assessing the effectiveness of treatments for these disorders is lacking. The Outcome Measures in Rheumatology (OMERACT) Foot and Ankle Working Group is developing a core outcome set for use in clinical trials and longitudinal observational studies in this area.

METHODS

A scoping review was performed to identify outcome domains in the existing literature. Clinical trials and observational studies comparing pharmacological, conservative or surgical interventions involving adult participants with any foot or ankle disorder in the following rheumatic and musculoskeletal diseases (RMDs) were eligible for inclusion: rheumatoid arthritis (RA), osteoarthritis (OA), spondyloarthropathies, crystal arthropathies and connective tissue diseases. Outcome domains were categorised according to the OMERACT Filter 2.1.

RESULTS

Outcome domains were extracted from 150 eligible studies. Most studies included participants with foot/ankle OA (63% of studies) or foot/ankle involvement in RA (29% of studies). Foot/ankle pain was the outcome domain most commonly measured (78% of studies), being the most frequently specified outcome domain across all RMDs. There was considerable heterogeneity in the other outcome domains measured, across core areas of manifestations (signs, symptoms, biomarkers), life impact, and societal/resource use. The group's progress to date, including findings from the scoping review, was presented and discussed during a virtual OMERACT Special Interest Group (SIG) in October 2022. During this meeting, feedback was sought amongst delegates regarding the scope of the core outcome set, and feedback was received on the next steps of the project, including focus group and Delphi methods.

CONCLUSION

Findings from the scoping review and feedback from the SIG will contribute to the development of a core outcome set for foot and ankle disorders in RMDs. The next steps are to determine which outcome domains are important to patients, followed by a Delphi exercise with key stakeholders to prioritise outcome domains.

Developing an Outcome Measures in Rheumatology (OMERACT) Core set of Outcome Measures for FOot and ankle disorders in RheumaTic and musculoskeletal diseases (COMFORT): core domain set study protocol

BACKGROUND

Foot and ankle involvement is common in rheumatic and musculoskeletal diseases (RMDs). High-quality evidence is lacking to determine the effectiveness of treatments for these disorders. Heterogeneity in the outcomes used across clinical trials and observational studies hinders the ability to compare findings, and some outcomes are not always meaningful to patients and end-users. The Core set of Outcome Measures for FOot and ankle disorders in RheumaTic and musculoskeletal diseases (COMFORT) study aims to develop a core outcome set (COS) for use in all trials of interventions for foot and ankle disorders in RMDs. This protocol addresses core outcome domains (what to measure) only. Future work will focus on core outcome measurement instruments (how to measure).

METHODS

COMFORT: Core Domain Set is a mixed-methods study involving the following: (i) identification of important outcome domains through literature reviews, qualitative interviews and focus groups with patients and (ii) prioritisation of domains through an online, modified Delphi consensus study and subsequent consensus meeting with representation from all stakeholder groups. Findings will be disseminated widely to enhance uptake.

CONCLUSIONS

This protocol details the development process and methodology to identify and prioritise domains for a COS in the novel area of foot and ankle disorders in RMDs. Future use of this standardised set of outcome domains, developed with all key stakeholders, will help address issues with outcome variability. This will facilitate comparing and combining study findings, thus improving the evidence base for treatments of these conditions. Future work will identify suitable outcome measurement instruments for each of the core domains.

TRIAL REGISTRATION

This study is registered with the Core Outcome Measures in Effectiveness Trials (COMET) database, as of June 2022: https://www.comet-initiative.org/Studies/Details/2081.

Design optimization procedure for an orthopedic insole having a continuously variable stiffness/shape to reduce the plantar pressure in the foot of a diabetic patient

Foot ulcers and lower-limb amputations are among the major problems in diabetic patients. Orthopedic insoles can reduce the risk of diabetic foot ulcers in patients through pressure redistribution on the bottom of the foot. The purpose of this study was to propose an optimization method to design the dedicated insoles for diabetic patients in order to decrease the maximum plantar pressure. At first, a three-dimensional finite element model of bones, ligaments and soft tissue of a diabetic patient's foot was created using CT scan images. Then, the foot plantar pressure was calculated by means of a finite element software. Next, the stiffness and shape of a simple flat insole were separately modified to reduce the maximum foot plantar pressure. The optimization method resulted in a dedicated insole design with a continuously variable stiffness/shape within its area that creates a smooth pressure distribution for the patient comfort. The results showed a 40% reduction in the maximum foot pressure, which we attribute to the modification of insole stiffness. In addition, the optimal shape of the proposed insole decreased the maximum plantar pressure by 25% compared to the flat insole.

Different types of foot orthoses effect on gait mechanics in patients with rheumatoid arthritis

Foot orthoses are a first line conservative treatment for foot impairments in patients with rheumatoid arthritis (RA), however their effect on gait mechanics is poorly understood. We aimed to compare changes in lower limb and foot mechanics between two types of commonly used foot orthoses (FO) with a control. Twenty-seven patients with rheumatoid arthritis participated in this crossover study. Two different types of FO (a medially wedged custom-made FO and a prefabricated FO with a metatarsal dome, respectively), were compared against a control insole. During gait, lower limb mechanics were analyzed using 3D motion capture, force plates, and an in-shoe pressure system. Inverse dynamics models were created in the Anybody Modeling System to calculate joint angles and joint moments during gait. Gait variables were analyzed using statistical parametric mapping. Compared to the control, the prefabricated FO had limited effect on gait mechanics. Compared to the control the custom-made FO reduced ankle plantarflexion moment with 0.4 %body weight * body height (BW * BH) between 66 and 76% of stance and ankle eversion moment was reduced 0.16% BW*BH between 3 and 40% of stance. Furthermore, it also reduced the average forefoot plantar pressure by 9 kPa between 20 and 62% of stance compared to the control. Changes in foot pressure distribution, joint moments and angles were most pronounced for custom-made FO compared to the prefabricated FO. The findings suggest that patients with RA and foot impairments may benefit more from an individualized FO strategy, if the aim of the treatment is to alter gait mechanics. (NCT03561688).

Effectiveness of custom-made foot orthoses in patients with systemic lupus erythaematosus: protocol for a randomised controlled trial

INTRODUCTION

Systemic lupus erythaematosus (SLE) is a chronic autoimmune disease of heterogeneous involvement. The disease may affect feet with a high prevalence of symptoms such as, for example, pain, forefoot and rearfoot deformities, and biomechanics dysfunctions. Custom-made foot orthoses (CMFO) have been previously reported to be effective in patients with other rheumatic diseases. However, as far as the authors know, there exist no studies about their effectiveness in SLE. This study aims at determining the effect of CMFO versus placebo flat cushioning insoles on pain, foot functionality, fatigue and quality of life in patients with SLE.

METHODS AND ANALYSIS

A randomised controlled trial would compare the effects of (1) CMFO and group B, which received a placebo, flat cushioning insoles, for 3 months. The main outcome measures are foot pain, foot functionality and foot-related disability. The secondary outcome measures are fatigue and quality of life.

ETHICS AND DISSEMINATION

The study has been approved by the Portal de Ética de la Investigación Biomédica de Andalucía ethical committee 1494-N-19. The results will be disseminated regardless of the magnitude or direction of effect.

TRIAL REGISTARTION NUMBER

Clinicaltrials.gov identifier NCT04098055.

Three-Dimensional Printing in Orthopedics: from the Basics to Surgical Applications

PURPOSE OF REVIEW

Additive manufacturing (AM) is a rapidly evolving field traditionally utilized in non-medical industries. Recently, the medical use of AM is expanding, especially in orthopedics. The goal of this article is presenting the principles of AM and its main applications in orthopedics.

RECENT FINDINGS

The main indications for AM in orthopedics are education, orthotics, surgical planning, surgical guides, and custom-made implants. Three-dimensional (3D) digital models can be obtained from tomographic scans using available free software. Then, it can be used to create a physical model, plan surgeries, or develop surgical guides which can aid the orthopedic surgeon during complex cases. Recent studies demonstrated the benefits of using printed models in educating patients and medical residents. Custom-made implants also have been evaluated with promising clinical outcomes. Using 3D technology has become a reality in orthopedics. Surgeons should expect exponential growth of its applications in the upcoming years. It is paramount that orthopedists get familiar with this disruptive technology.

Outcomes and potential mechanism of a protocol to optimize foot orthoses in patients with rheumatoid arthritis

Background

Foot problems are highly prevalent in patients with rheumatoid arthritis. Treatment of foot problems related to rheumatoid arthritis often consists of custom made foot orthoses. One of the assumed working mechanisms of foot orthoses is redistribution of plantar pressure by creating a larger weight bearing area. Overall, the reported treatment effect of foot orthoses on foot pain in rheumatoid arthritis is small to medium. Therefore, we developed a foot orthoses optimization protocol for evaluation and adaptation of foot orthoses by using the feedback of in-shoe plantar pressure measurements. The objectives of the present study were: 1) to evaluate the 3-months outcomes of foot orthoses developed according to the protocol on pain, physical functioning and forefoot plantar pressure in patients with foot problems related to rheumatoid arthritis, and 2) to determine the relationship between change in forefoot plantar pressure and change in pain and physical functioning.

Methods

Forty-five patients with foot problems related to rheumatoid arthritis were included and received foot orthoses developed according to the protocol. Outcome measures were assessed at baseline and after three months of wearing foot orthoses in 38 patients. Change scores and effect sizes (ES) were calculated for pain, physical functioning and plantar pressure. In a subgroup of patients with combined forefoot pain and high plantar pressure, the relationship between change in plantar pressure and change in pain and physical functioning was analyzed.

Results

In the total group of 38 patients, statistically significant changes in pain (ES 0.69), physical functioning (ES 0.82) and forefoot plantar pressure (ES 0.35) were found. In the subgroup (n = 23) no statistically significant relationships were found between change in plantar pressure and change in pain or physical functioning.

Conclusion

Foot orthoses developed according to a protocol for improving the plantar pressure redistribution properties lead to medium to large improvements in pain and physical functioning. The hypothesis that more pressure reduction would lead to better clinical outcomes could not be proven.

Advances in Orthotic and Prosthetic Manufacturing: A Technology Review

In this work, the recent advances for rapid prototyping in the orthoprosthetic industry are presented. Specifically, the manufacturing process of orthoprosthetic aids are analysed, as thier use is widely extended in orthopedic surgery. These devices are devoted to either correct posture or movement (orthosis) or to substitute a body segment (prosthesis) while maintaining functionality. The manufacturing process is traditionally mainly hand-crafted: The subject's morphology is taken by means of plaster molds, and the manufacture is performed individually, by adjusting the prototype over the subject. This industry has incorporated computer aided design (CAD), computed aided engineering (CAE) and computed aided manufacturing (CAM) tools; however, the true revolution is the result of the application of rapid prototyping technologies (RPT). Techniques such as fused deposition modelling (FDM), selective laser sintering (SLS), laminated object manufacturing (LOM), and 3D printing (3DP) are some examples of the available methodologies in the manufacturing industry that, step by step, are being included in the rehabilitation engineering market-an engineering field with growth and prospects in the coming years. In this work we analyse different methodologies for additive manufacturing along with the principal methods for collecting 3D body shapes and their application in the manufacturing of functional devices for rehabilitation purposes such as splints, ankle-foot orthoses, or arm prostheses.

Systematic review on the comparative effectiveness of foot orthoses in patients with rheumatoid arthritis

Background

Foot orthoses (FOs) are prescribed as an important conservative treatment option in patients with foot problems related to rheumatoid arthritis. However, a broad variation in FOs is used, both in clinical practice and in research. To date, there is no overview on the outcomes of the treatment with different kinds of FOs in patients with rheumatoid arthritis and a specific foot problem. The objectives of the present study were to summarize the comparative effectiveness of FOs in the treatment of various foot problems in patients with rheumatoid arthritis, on the primary outcomes foot function and foot pain, and the secondary outcomes physical functioning, health related quality of life, compliance, adverse events, the costs of FOs and patient satisfaction.

Methods

Studies comparing different kinds of FOs, with a presumed therapeutic effect, in the treatment of foot problems related to rheumatoid arthritis were included. A literature search was conducted in The Cochrane Central Registry for Controlled Trials (CENTRAL), PubMed, EMBASE and PEDro up to May 18th, 2018. Data was meta-analyzed, when this was not possible qualitative data analysis was performed.

Results

Ten studies were identified, with a total number of 235 patients. These studies made a comparison between different materials used (soft versus semi-rigid), types of FOs (custom-made versus ready-made; total-contact versus non-total contact), or modifications applied (metatarsal bars versus domes). Also, different techniques to construct custom-made FOs were compared (standard custom-molding techniques versus more sophisticated techniques). A medium effect for (immediate) reduction of forefoot plantar pressure was found in favor of treatment with soft FOs compared to semi-rigid FOs (SMD 0.60, 95% CI 0.07-1.14; P = 0.03; 28 participants). Other comparisons between FOs resulted in non-significant effects or inconclusive evidence for one kind of FOs over the other.

Conclusions

Foot orthoses made of soft materials may lead to more (immediate) forefoot plantar pressure reduction compared to foot orthoses constructed of semi-rigid materials. Definitive high quality RCTs, with adequate sample sizes and long-term follow-up, are needed to investigate the comparative (cost-) effectiveness of different kinds of foot orthoses for the treatment of foot problems related to rheumatoid arthritis.

Functional gradient structural design of customized diabetic insoles

Diabetic foot is a common and serious complication of diabetes, largely due to sensory neuropathy and excessive mechanical stresses. Studies have shown that reducing the contact pressure can effectively lower the incidence of diabetic foot. A new design method is proposed in this study for optimizing the stress distribution of the contact surfaces between the foot and the insole by applying functional gradient structural properties to the insole. Finite element analysis was employed for studying the contact mechanics, which laid the foundation for modulus readjustment during the optimization process. The moduli of the materials were correlated to the properties of the structural porous units. The customized insoles were manufactured using additive manufacturing technology and put into mechanical test. Results show that the designed insole helps in increasing the foot contact area by approximately 30% and reducing the peak contact pressure by 35%. Hence, the proposed method can be used to design customized insoles, particularly diabetic insoles, by offering better contact mechanics and good potential for reducing the severity of diabetic foot. The methodology is equally applicable to other designs involving optimization of material properties.

Foot orthoses for people with rheumatoid arthritis: a survey of prescription habits among podiatrists

Background

Guidelines recommend foot orthoses for people with both early (< 2 years) and established rheumatoid arthritis (RA). While prefabricated foot orthoses are cheaper and can exhibit comparable effects to customised devices, the available evidence for their effectiveness is inconsistent. Little is known about what types of foot orthoses clinicians prescribe. This study describes the foot orthoses prescription habits of podiatrists for people with rheumatoid arthritis.

Methods

One hundred and eighty-three podiatrists from the United Kingdom (UK) (n = 88), Australia (n = 68) and New Zealand (n = 27) completed a self-administered, online survey regarding the types of foot orthoses prescribed in clinical practice for people with RA. This study forms part of a wider international survey exploring foot orthosis prescription habits.

Results

UK respondents were more likely to prescribe prefabricated orthoses for early RA (n = 47, 53%) and customised orthoses for established RA (n = 47, 53%). Respondents in Australia were more likely to prescribe customised orthoses for both early (n = 32, 47%) and established (n = 46, 68%) RA, whilst respondents in New Zealand were more likely to prescribe prefabricated orthoses for both early (n = 16, 59%) and established (n = 10, 37%) disease.

Irrespective of disease stage, the use of foam impression boxes was more prevalent in the UK and New Zealand when capturing a model of the feet prior to manufacturing customised orthoses. In contrast, electronic scanning and plaster of Paris were more common in Australia. Computer aided manufacture was utilised more frequently among respondents in Australia than in the UK and New Zealand. Respondents in all three countries specified more flexible shell materials for established RA, compared to early disease. Cushioning top covers (e.g. PORON® or polyurethane) were most frequently specified in all countries for both disease stages.

Conclusions

Considerable variation was seen in the self-reported foot orthoses prescription habits of respondents for people with RA. Variation between countries and disease stage was seen in type of orthoses, specific brands, manufacturing methods, and materials prescribed. The results allow podiatrists and broader health service providers to compare their practice against reported national and international patterns.

Electronic supplementary material

The online version of this article (10.1186/s13047-019-0314-5) contains supplementary material, which is available to authorized users.

Effectiveness of foot orthoses in patients with rheumatoid arthritis related to disability and pain: a systematic review and meta-analysis

BACKGROUND

Epidemiological studies consistently report a 90% prevalence of foot pain. Mechanical and other non-pharmacological interventions such as orthoses and footwear can play an important role in managing foot pathology in patients whose systemic disease is controlled. The effectiveness of treatment with insoles has been examined in various randomised controlled trials, which have reported immediate clinical improvements, with reduced foot pain and disability and enhanced functionality. The aim of this systematic review is to determine the effectiveness of foot orthoses in patients with rheumatoid arthritis (RA), in comparison with other treatments, in terms of enhanced disability and reduced pain.

METHODS

A systematic review and meta-analysis was conducted of a number of randomised controlled trials focusing on patients with RA. The search was conducted in Cochrane, CINAHL, PubMed, EMBASE, SCOPUS and Cuiden, by means of an independent peer review. The Mesh terms and fields used were foot, ankle, joint, RA, foot, orthosis, insole and foot orthosis.

RESULTS

Of the initial 118 studies considered, 5 were included in the final systematic review and meta-analysis. These five studies had enrolled a total of 301 participants, with follow-up periods ranging from 4 to 36 months. Although the use of orthoses seems to alleviate foot pain, our meta-analysis did not reveal statistically significant differences between control and intervention groups regarding long- and short-term pain relief and/or reduced disability.

CONCLUSIONS

Foot orthoses can relieve pain and disability and enhance patients, but no significant differences were found between control and intervention groups.

A protocol for a randomised controlled trial of prefabricated versus customised foot orthoses for people with rheumatoid arthritis: the FOCOS RA trial [Foot Orthoses - Customised v Off-the-Shelf in Rheumatoid Arthritis]

BACKGROUND

Foot pain is common in rheumatoid arthritis and appears to persist despite modern day medical management. Several clinical practice guidelines currently recommend the use of foot orthoses for the treatment of foot pain in people with rheumatoid arthritis. However, an evidence gap currently exists concerning the comparative clinical- and cost-effectiveness of prefabricated and customised foot orthoses in people with early rheumatoid arthritis. Early intervention with orthotics may offer the best opportunity for positive therapeutic outcomes. The primary aim of this study is to evaluate the comparative clinical- and cost-effectiveness of prefabricated versus customised orthoses for reducing foot pain over 12 months.

METHODS/DESIGN

This is a multi-centre two-arm parallel randomised controlled trial comparing prefabricated versus customised orthoses in participants with early rheumatoid arthritis (< 2 years disease duration). A total of 160 (a minimum of 80 randomised to each arm) eligible participants will be recruited from United Kingdom National Health Service Rheumatology Outpatient Clinics. The primary outcome will be foot pain measured via the Foot Function Index pain subscale at 12 months. Secondary outcomes will include foot related impairments and disability via the Foot Impact Scale for rheumatoid arthritis, global functional status via the Stanford Health Assessment Questionnaire, foot disease activity via the Rheumatoid Arthritis Foot Disease Activity Index, and health-related quality of life at baseline, 6 and 12 months. Process outcomes will include recruitment/retention rates, data completion rates, intervention adherence rates, and participant intervention and trial participation satisfaction. Cost-utility and cost-effectiveness analyses will be undertaken.

DISCUSSION

Outcome measures collected at baseline, 6 and 12 months will be used to evaluate the comparative clinical- and cost- effectiveness of customised versus prefabricated orthoses for this treatment of early rheumatoid arthritis foot conditions. This trial will help to guide orthotic prescription recommendations for the management of foot pain for people with early rheumatoid arthritis in future.

TRIAL REGISTRATION

ISRCTN13654421. Registered 09 February 2016.

Clinical effectiveness and cost-effectiveness of foot orthoses for people with established rheumatoid arthritis: an exploratory clinical trial

OBJECTIVES

Foot orthoses are commonly prescribed as an intervention for people with rheumatoid arthritis (RA). Data relating to the cost-effectiveness of foot orthoses in people with RA are limited. The aim was to evaluate the clinical and cost-effectiveness of two types of foot orthoses in people with established RA.

METHOD

A single-blind randomized controlled trial was undertaken to compare custom-made foot orthoses (CMFOs) and simple insoles (SIs) in 41 people with established RA. The Foot Function Index (FFI) was used to measure foot pain, disability, and functional limitation. Costs were estimated from the perspective of the UK National Health Service (NHS), societal (patient and family) perspective, and secondary care resource use in terms of the intervention and staff time. Effects were assessed in terms of health gain expressed as quality-adjusted life years (QALYs).

RESULTS

At baseline, 20 participants received a CMFO and 21 participants received an SI. After 16 weeks foot pain improved in both the CMFOs (p = 0.000) and the SIs (p < 0.01). However, disability scores improved for CMFOs (p < 0.001) but not for SIs (p = 0.40). The cost-effectiveness results demonstrated no difference in cost between the arms (CMFOs: £159.10; SIs: £79.10; p = 0.35), with the CMFOs being less effective in terms of cost per QALY gain (p < 0.001).

CONCLUSIONS

In people with established RA, semi-rigid customized foot orthoses can improve pain and disability scores in comparison to simple insoles. From a cost-effectiveness perspective, the customized foot orthoses were far more expensive to manufacture, with no significant cost per QALY gain.

Simplified versus geometrically accurate models of forefoot anatomy to predict plantar pressures: A finite element study

Integration of patient-specific biomechanical measurements into the design of therapeutic footwear has been shown to improve clinical outcomes in patients with diabetic foot disease. The addition of numerical simulations intended to optimise intervention design may help to build on these advances, however at present the time and labour required to generate and run personalised models of foot anatomy restrict their routine clinical utility. In this study we developed second-generation personalised simple finite element (FE) models of the forefoot with varying geometric fidelities. Plantar pressure predictions from barefoot, shod, and shod with insole simulations using simplified models were compared to those obtained from CT-based FE models incorporating more detailed representations of bone and tissue geometry. A simplified model including representations of metatarsals based on simple geometric shapes, embedded within a contoured soft tissue block with outer geometry acquired from a 3D surface scan was found to provide pressure predictions closest to the more complex model, with mean differences of 13.3kPa (SD 13.4), 12.52kPa (SD 11.9) and 9.6kPa (SD 9.3) for barefoot, shod, and insole conditions respectively. The simplified model design could be produced in <1h compared to >3h in the case of the more detailed model, and solved on average 24% faster. FE models of the forefoot based on simplified geometric representations of the metatarsal bones and soft tissue surface geometry from 3D surface scans may potentially provide a simulation approach with improved clinical utility, however further validity testing around a range of therapeutic footwear types is required.

Recommendations for the conduct of efficacy trials of treatment devices for osteoarthritis: a report from a working group of the Arthritis Research UK Osteoarthritis and Crystal Diseases Clinical Studies Group

OBJECTIVE

There are unique challenges to designing and carrying out high-quality trials testing therapeutic devices in OA and other rheumatic diseases. Such challenges include determining the mechanisms of action of the device and the appropriate sham. Design of device trials is more challenging than that of placebo-controlled drug trials. Our aim was to develop recommendations for designing device trials.

METHODS

An Arthritis Research UK study group comprised of 30 rheumatologists, physiotherapists, podiatrists, engineers, orthopaedists, trialists and patients, including many who have carried out device trials, met and (using a Delphi-styled approach) came to consensus on recommendations for device trials.

RESULTS

Challenges unique to device trials include defining the mechanism of action of the device and, therefore, the appropriate sham that provides a placebo effect without duplicating the action of the active device. Should there be no clear-cut mechanism of action, a three-arm trial including a no-treatment arm and one with presumed sham action was recommended. For individualized devices, generalizable indications and standardization of the devices are needed so that treatments can be generalized.

CONCLUSION

A consensus set of recommendations for device trials was developed, providing a basis for improved trial design, and hopefully improvement in the number of effective therapeutic devices for rheumatic diseases.

Dynamic plantar loading index detects altered foot function in individuals with rheumatoid arthritis but not changes due to orthotic use

BACKGROUND

Altered foot function is common in individuals with rheumatoid arthritis. Plantar pressure distributions during gait are regularly assessed in this patient group; however, the association between frequently reported magnitude-based pressure variables and clinical outcomes has not been clearly established. Recently, a novel approach to the analysis of plantar pressure distributions throughout stance phase, the dynamic plantar loading index, has been proposed. This study aimed to assess the utility of this index for measuring foot function in individuals with rheumatoid arthritis.

METHODS

Barefoot plantar pressures during gait were measured in 63 patients with rheumatoid arthritis and 51 matched controls. Additionally, 15 individuals with rheumatoid arthritis had in-shoe plantar pressures measured whilst walking in standardized footwear for two conditions: shoes-only; and shoes with prescribed custom foot orthoses. The dynamic plantar loading index was determined for all participants and conditions. Patient and control groups were compared for significant differences as were the shod and orthosis conditions.

FINDINGS

The patient group was found to have a mean index of 0.19, significantly lower than the control group's index of 0.32 (p>0.001, 95% CI [0.054, 0.197]). No significant differences were found between the shoe-only and shoe plus orthosis conditions. The loading index was found to correlate with clinical measures of structural deformity.

INTERPRETATION

The dynamic plantar loading index may be a useful tool for researchers and clinicians looking to objectively assess dynamic foot function in patients with rheumatoid arthritis; however, it may be unresponsive to changes caused by orthotic interventions in this patient group.

Offloading the diabetic and ischemic foot: solutions for the vascular specialist

For generations, the use of techniques to defer skin pressure and protect the lower-extremity wound has been a cardinal goal to achieve therapeutic success and healing. Choosing the appropriate postoperative offloading device or shoe is often difficult, as it is challenging to merge optimal mechanical protection with clinical realities and patient needs. The gold standard for offloading remains the total contact cast, yet it receives minimal utilization in the clinical setting. Other devices have shown benefit, including the removable cast walker, instant total contact cast, and depth inlay shoes, for preventative measures. Ultimately, any plantar, lower-extremity wound must receive some form of external pressure reduction to reach acceptable rates of healing. Future technologies will aid these measures by providing body-worn constant monitoring systems and more effective offloading via patient-specific exoskeletons. This review is a supplemental update on the available wound offloading modalities based on logic-driven research regarding pressure relief across the diabetic neuropathic or impaired perfusion foot.

How Can I Maintain My Patient With Diabetes and History of Foot Ulcer in Remission?

Patients with diabetes and previous history of ulceration occupy the highest category of risk for reulceration and amputation. Annual recurrence rates of diabetic ulcerations have been reported as high as 34%, 61%, and 70% at 1, 3, and 5 years, respectively, with studies reporting 20% to 58% recurrence rate within 1 year. As the ever growing epidemic of diabetes expands globally, this sequelae of diabetic complication will continue to require increasing resources from the healthcare community to effectively manage. Recent data suggest that removal of preventative podiatric care from statewide reimbursement systems lead to significant and sustained increases in hospital admission (37%), charges (38%), length of stay (23%), and severe aggregate outcomes including amputation, sepsis and death (49%). The addition of comorbidities such as peripheral artery disease, poor nutrition, and non-adherence to preventive therapies not only increase a patient’s likelihood for ulcer recurrence, but also cost of care and certainty of hospital admission. Currently, numerous efforts, guidelines, and industry generated products exist to prolong remission from ulceration; however, the clinical science for treating this patient population calls for much more effort. Despite this, data continue to suggest to demonstrate that appropriate follow-up care, shoe and insole modification, and patient education play a central role in reducing reulceration and amputation. Novel modalities for offloading and wearable sensor technologies offer the advantage of round-the-clock, patient specific and active response healthcare. These have the potential to detect, or even prevent, many wounds before they begin.

An ultrasound based non-invasive method for the measurement of intrinsic foot kinematics during gait

Soft tissue artefact (STA) and marker placement variability are sources of error when measuring the intrinsic kinematics of the foot. This study aims to demonstrate a non-invasive, combined ultrasound and motion capture (US/MC) technique to directly measure foot skeletal motion. The novel approach is compared to a standard motion capture protocol. Fourteen participants underwent instrumented barefoot analysis of foot motion during gait. Markers were attached to foot allowing medial longitudinal arch angle and navicular height to be determined. For the US/MC technique, the navicular marker was replaced by an ultrasound transducer which was secured to the foot allowing the skeletal landmark to be imaged. Ultrasound cineloops showing the location of the navicular tuberosity during the walking trials were synchronised with motion capture measurements and markers mounted on the probe allowed the true position of the bony landmark to be determined throughout stance phase. Two discrete variables, minimum navicular height and maximum MLA angle, were compared between the standard and US/MC protocols. Significant differences between minimum navicular height (P=0.004, 95% CI (1.57, 6.54)) and maximum medial longitudinal arch angle (P=0.0034, 95% CI (13.8, 3.4)) were found between the measurement methods. The individual effects of STA and marker placement error were also assessed. US/MC is a non-invasive technique which may help to provide more accurate measurements of intrinsic foot kinematics.