Multisite Evaluation of a Custom Energy-Storing Carbon Fiber Orthosis for Patients with Residual Disability After Lower-Limb Trauma

The effect of carbon fiber custom dynamic orthosis type on kinematics and kinetics of lower extremity joints in individuals with lower limb traumatic injuries

BACKGROUND

Carbon fiber custom dynamic orthoses have been used to improve gait mechanics after lower limb trauma in military service members, with the goal of restoring function and improving outcomes. However, the effects of commercially available carbon fiber orthoses available to civilians on lower extremity joint kinetics and kinematics are poorly understood.

RESEARCH QUESTION

The aim of this study was to examine the effect of two commercially available orthoses on lower extremity kinematics and kinetics in individuals with lower limb trauma.

METHODS

A total of 23 participants with a lower extremity traumatic injury underwent gait analysis while walking without an orthosis, and while wearing a monolithic carbon fiber orthosis or while wearing a modular carbon fiber orthosis, in a randomized order. Study participants accommodated to each orthosis for three months prior to testing. Joint kinematics and kinetics at the ankle, knee, and hip joints, and ground reaction forces were assessed.

RESULTS

The two study orthoses significantly reduced ankle motion compared to no orthosis, with large effect sizes observed. Peak plantarflexor moment was greater with the modular orthosis compared to the monolithic orthosis. Ankle push-off power did not differ between orthoses but was significantly reduced relative to no orthosis. Push-off power with the study orthoses was over 25% greater as compared to previous studies with military orthoses. Peak loading response power generation at the knee was greater with the monolithic orthosis as compared to the modular orthosis. The kinematics and kinetics at the hip did not differ between orthoses.

SIGNIFICANCE

Orthoses commonly used in civilian settings to treat limb trauma primarily alter joint kinematics and kinetics at the ankle, in a manner consistent with orthoses used in the military. Additionally, despite the apparent large differences in the designs of the two study orthoses, between-orthosis differences on gait mechanics were limited.

Influence of custom dynamic orthoses on tibiotalar joint reaction force and contact stress: A cadaveric study

Post-traumatic osteoarthritis (PTOA) often develops following tibial pilon fractures. Evidence suggesting PTOA development is driven by elevated articular contact stress from residual malreduction has led surgeons to strive for precise articular reduction, typically at the cost of extended operative time. Post-operative bracing using carbon fiber custom dynamic orthoses (CDOs) offers another means to decrease tibiotalar joint reaction force (JRF) and contact stress. The purpose of this cadaveric study was to measure how CDO stiffness influences ankle JRF and contact stress over the stance phase of gait. A servohydraulic load frame was used to test five cadaver ankles, with axial loading (240-330 N) and pneumatic actuation of the Achilles tendon (50-436 N) serving to quasi-statically model multiple points in the stance phase of gait. Three CDO rotational stiffness conditions were tested: (1) No CDO-0 Nm/deg, (2) low stiffness CDO-1.8 Nm/deg, and (3) moderate stiffness CDO-2.3 Nm/deg. JRF and contact stresses were measured using a piezoresistive pressure sensor inserted into the tibiotalar joint. An insole plantar pressure sensor placed between the cadaveric foot and CDO footplate measured limb/device interactions via the plantar center of pressure (COP). As limb loading progressed through stance, the plantar COP progressed from hindfoot to forefoot, as it would in normal gait. Both CDOs demonstrated decreases in JRF, reaching as high as 32% for the low CDO and 26% for the moderate CDO, with associated decreases in contact stress. This suggests that post-operative bracing could lessen PTOA risk after pilon fractures.

Post-Traumatic Arthritis of the Knee and Ankle

Post-traumatic osteoarthritis (PTOA) occurs following injury to joints. It accounts for approximately 12% of osteoarthritis and has far-reaching effects on individual patients and social/health care systems. Present work focuses on evaluating the role of the post-traumatic inflammatory response in the development and progression of the disease. As there is minimal evidence to suggest the capacity of cartilage to undergo self-healing, most of this work focuses strictly on the avoidance or prevention of PTOA as opposed to treatment solutions following its onset. Ongoing and future investigations may reveal therapeutic targets for possible intervention and ultimately the prophylaxis of PTOA development.

Predictors of long-term pain and function in individuals who received a custom dynamic orthosis and device-centric care pathway

INTRODUCTION

Carbon fiber custom dynamic orthoses (CDOs) have been shown to effectively reduce pain and improve function in military service members with lower-limb impairment, but data are limited for civilians.

OBJECTIVES

To evaluate the long-term outcomes of individuals who completed a CDO-centric care pathway in a civilian clinic by comparing baseline pain, mobility, and function with outcomes at long-term follow-up. To identify baseline characteristics and postintervention outcomes predictive of outcomes at long-term follow-up.

METHODS

Records of 131 adult patients who received a CDO and CDO-centric training were reviewed. Patient-reported measures of pain and physical function and timed assessment of walking and agility collected during routine clinical care were extracted. These patients were contacted on average 4 (±1) years postintervention to complete a survey including measures of pain and physical function.

RESULTS

The 63 participants who responded reported improved or greatly improved function, maximum pain, and typical pain on average, irrespective of age or sex ( P < 0.001). Change in function from baseline to long-term follow-up was predicted by short-term change in function (35.1% of the variance; P < 0.001). Change in pain from baseline to long-term follow-up was predicted by baseline typical pain and change in four square step test time (63% of variance; P < 0.001).

CONCLUSIONS

Most survey respondents reported positive outcomes. Long-term pain reduction and improved function were predicted by baseline status and by short-term changes associated with receiving a CDO and completing an intensive training program.

The effect of carbon fiber custom dynamic orthosis use and design on center of pressure progression and perceived smoothness in individuals with lower limb trauma

BACKGROUND

Carbon-fiber custom dynamic orthoses are used to improve gait and limb function following lower limb trauma in specialty centers. However, the effects of commercially available orthoses on center of pressure progression and patient perception of orthosis smoothness during walking are poorly understood.

METHODS

In total, 16 participants with a unilateral lower extremity traumatic injury underwent gait analysis when walking without an orthosis, and while wearing monolithic and modular devices, in a randomized order. Device alignment, stiffness, participant rating of perceived device smoothness, center of pressure velocity, and ankle zero moment crossing were assessed.

FINDINGS

The modular device was approximately twice as stiff as the monolithic device. Alignment, smoothness ratings, peak magnitude of center of pressure velocity, and zero moment crossing were not different between study devices. The time to peak center of pressure velocity occurred significantly later for the modular device compared to the monolithic and no orthosis conditions, with large effect sizes observed.

INTERPRETATION

Commercially available orthoses commonly used to treat limb trauma affect the timing of center of pressure progression relative to walking without an orthosis. Despite multiple design differences, monolithic and modular orthoses included in this study did not differ with respect to other measures of center of pressure progression. Perceived smoothness ratings were approximately 40% greater with the study orthoses as compared to previous studies in specialty centers, which may be due to a more gradual center of pressure progression, as indicted by lower peak magnitude of center of pressure velocity with both study orthoses.

A patient-centered 'test-drive' strategy for ankle-foot orthosis prescription: Protocol for a randomized participant-blinded trial

BACKGROUND

Ankle-foot orthoses (AFOs) are commonly used to overcome mobility limitations related to lower limb musculoskeletal injury. Despite a multitude of AFOs to choose from, there is scant evidence to guide AFO prescription and limited opportunities for AFO users to provide experiential input during the process. To address these limitations in the current prescription process, this study evaluates a novel, user-centered and personalized 'test-drive' strategy using a robotic exoskeleton ('AFO emulator') to emulate commercial AFO mechanical properties (i.e., stiffness). The study will determine if brief, in-lab trials (with emulated or actual AFOs) can predict longer term preference, satisfaction, and mobility outcomes after community trials (with the actual AFOs). Secondarily, it will compare the in-lab experience of walking between actual vs. emulated AFOs.

METHODS AND ANALYSIS

In this participant-blinded, randomized crossover study we will recruit up to fifty-eight individuals with lower limb musculoskeletal injuries who currently use an AFO. Participants will walk on a treadmill with three actual AFOs and corresponding emulated AFOs for the "in-lab" assessments. For the community trial assessment, participants will wear each of the actual AFOs for a two-week period during activities of daily living. Performance-based and user-reported measures of preference and mobility will be compared between short- and long-term trials (i.e., in-lab vs. two-week community trials), and between in-lab trials (emulated vs. actual AFOs).

TRIAL REGISTRATION

The study was prospectively registered at www.clininicaltrials.gov (Clinical Trials Study ID: NCT06113159). Date: November 1st 2023. https://classic.clinicaltrials.gov/ct2/show/NCT06113159.

Lower Extremity Assistive Devices (LEADs): A Contemporary Literature Review

Lower extremity ambulatory assistive devices (LEADs) are important augments that provide mobility and stability when weightbearing is restricted in the setting of injury, surgery, or balance disorders. In order to optimize patient safety and function when prescribing these devices, it is essential for the orthopaedic surgeon to have a firm understanding of their specific indications, proper fitting, energy demand, biomechanical advantages, and potential complications. Comprehension of normal gait cadence, identification of the functional deficit present and knowledge of available options will assist in safely prescribing the proper device. Over the last decade, newer alternatives to traditional LEADs (canes, crutches, walkers) have become available, including the rolling knee scooter and hands-free single crutch. These have been developed to improve mobility and independence; however, it is necessary to appreciate their limitations when prescribing them to patients. This review will provide an update on normal and pathologic gait biomechanics as well as the most common types of LEADs currently available to the orthopaedic surgeon, their indications, important considerations, proper fitting, associated energy expenditure, and complications.

Short-term effect of a carbon fiber custom dynamic orthosis and integrated rehabilitation on self-reported physical function, pain, speed, and agility in civilians

BACKGROUND

Ankle-foot orthoses (AFOs) are widely used to restore mobility and reduce pain in individuals with lower extremity pain and disability. The use of a carbon fiber custom dynamic orthosis (CDO) with integrated physical training and psychosocial intervention has been shown to improve outcomes in a military setting, but civilian data are limited.

OBJECTIVES

To use existing clinical data to evaluate the initial effectiveness of an integrated CDO and rehabilitative program and identify baseline characteristics that impact patient response to the intervention.

STUDY DESIGN

Retrospective cohort.

METHODS

Records of 131 adult patients who received a CDO and device specific training were reviewed. Patient-reported measures of pain and lower extremity function and physical measurements of walking and agility were extracted at baseline and on training completion.

RESULTS

A majority of patients reported improved or greatly improved physical function (92%), maximum pain (69%), and typical pain (55%) and experienced improved or greatly improved walking speed (92%) and agility (52%) irrespective of age and sex. Regression models for examining short-term improvement in pain and physical function accounted for 52% (p < 0.001) and 26% (p < 0.001) of the outcome variance, respectively. Improvement in typical pain was influenced by baseline typical and maximum pain, and functional improvement was influenced by sex and baseline physical function.

CONCLUSIONS

Most patients (92.4%) reported a positive initial outcome after intervention as measured using patient-reported and objective measures.

Carbon fiber ankle-foot orthoses in impaired populations: A systematic review

BACKGROUND

Carbon fiber is increasingly being used in ankle-foot orthoses (AFOs). Orthotic devices and carbon fiber-containing devices have been shown to reduce pain and improve function in multiple patient populations. Although the number of publications and interest in carbon fiber AFOs is growing, a systematic evaluation of their effects is lacking.

OBJECTIVES

To characterize the effects of carbon fiber AFOs in impaired individuals.

STUDY DESIGN

Qualitative systematic review.

METHODS

Systematic searches in PubMed, Embase, CINAHL, and Cochrane Library were completed in July 2020. The results were deduplicated, screened, and assessed for quality by independent reviewers. Articles were excluded if they had nonhuman subjects, only healthy subjects, or included active control systems, motors, or other power sources.

RESULTS

Seventy-eight articles were included in the qualitative synthesis. Most articles were of low to moderate methodological quality. Five commonly used devices were identified: the Intrepid Dynamic Exoskeletal Orthosis, ToeOff, WalkOn, Neuro Swing, and Chignon. The devices have unique designs and are associated with specific populations. The Intrepid Dynamic Exoskeletal Orthosis was used in individuals with lower-limb trauma, the Neuro Swing and ToeOff in individuals with neurological disorders, the Chignon in individuals with hemiplegia and stroke, and the WalkOn in people with hemiplegia and cerebral palsy. Each device produced favorable outcomes in their respective populations of interest, such as increased walking speed, reduced pain, or improved balance.

CONCLUSIONS

The mechanical characteristics and designs of carbon fiber AFOs improve outcomes in the populations in which they are most studied. Future literature should diligently report patient population, device used, and fitting procedures.

The Major Extremity Trauma Research Consortium: Development and Impact of an Orthopaedic Trauma Research Program

The Major Extremity Trauma Research Consortium (METRC) is a unique and ongoing military-civilian collaboration that resulted in the largest orthopaedic trauma research enterprise to date. The Consortium was established in September 2009 with funding from the Department of Defense. It employs a centralized data coordinating center and has grown into a network of nearly 400 investigators at 70 clinical centers. METRC conducts large multicenter clinical research studies selected and designed to improve outcomes among severely injured military and civilian patients with extremity trauma. Over the past decade, the consortium has implemented 35 such studies distributed among 19 principal investigators, enrolled more than 23,000 patients, published 61 articles, and received more than $150 million in funding from the Department of Defense, Patient Centered Outcomes Research Institute, and National Institutes of Health. This unique multidisciplinary research platform is a powerful community capable of addressing the challenging issues related to the evaluation, treatment, and recovery after severe extremity trauma. This body of work received the 2023 Elizabeth Winston Lanier Kappa Delta Award. An overview of the METRC development, organization, and research focus areas is presented.

Passive Dynamic Ankle Foot Orthoses Use in Civilian Patients with Arthritic Conditions of the Foot and Ankle

Background

Nonsurgical interventions such as bracing with ankle foot orthoses (AFOs) aim to assist, restore, and redirect weightbearing forces to address difficulty with mobilization. We identified a custom carbon fiber passive dynamic ankle foot orthosis (PDAFO) that was designed to meet the needs of military combat veterans. We sought to evaluate the off-loading properties of one model of PDAFO (ExoSym) in a civilian population.

Methods

Civilian patients 18 years or older were prescribed a PDAFO by a single surgeon. Pedobarographic data were obtained using the Tekscan F-Scan system. With the insole, participants were instructed to walk at a self-selected pace along a 20 m walkway under 3 conditions: (1) insole placed in between the brace and foot (over); (2) insole placed between the brace and insole of the shoe (under); (3) without the brace, the insole was placed in between the foot and insole of the shoe in both limbs (without).For assessment, forefoot and heel areas were evaluated with respect to maximal force, force*time integral (FTI), maximal contact area, maximal contact pressure, pressure*time integral (PTI), center of force (COF) excursion.

Results

Six patients with arthritic foot and ankle conditions completed pedobarographic assessment for analysis. The brace reduced forefoot maximal force and contact pressures by 66% and 49%, respectively (538 ± 236 to 185 ± 130 N [P < .001], and 99 ± 38 to 50 ± 24 P < .002). Additionally, participants were observed to load the forefoot portion of the brace with double the maximum contact pressures compared to the unbraced foot (204 ± 57 to 99 ± 38 kPa, P < .001).

Conclusion

The results of this study showed that the PDAFO unloaded substantial force and pressure experienced by the forefoot. Participants loaded the brace to a greater extent than when going unbraced. ADAFO can provide measurable pressure relief for patients with arthritic conditions.

Level of Evidence

Level IV, case series.

A modified passive-dynamic ankle-foot orthosis: can it prevent amputation and arthrodesis in patients with ankle-foot trauma?

INTRODUCTION

High-energy lower extremity trauma (HELET) may cause severe damage within the foot-ankle complex. Occasionally, arthrodesis or amputation are the only remaining options to increase activity levels. The modified passive dynamic ankle-foot orthosis (PDAFO) may prove to be a nonsurgical alternative. This study evaluated the effect of a modified PDAFO with a 6-week training program on pain and performance in patients after HELET.

MATERIALS AND METHODS

A retrospective cohort study was conducted on seventeen patients who considered an arthrodesis or an amputation after HELET. In an attempt to avoid surgery, the modified PDAFO with a 6-week training program was provided. Pain scores was measured with the Numeric Rating Scale and administered at the start of testing, immediately after the two performance tests and at the end of the day of testing. Performance was evaluated with the 6-min walk test (6MWT) and the Comprehensive high-level activity mobility predictor (CHAMP).

RESULTS

A significant pain reduction was achieved after the treatment procedure. At the start of the test days (p = 0.002), after the 6MWT (p = 0.001), after the CHAMP (p < 0.001) and at the end of the day (p < 0.001). In addition, a significant improvement on performance was observed in the 6MWT (p < 0.001) and the CHAMP (p = 0.01). None of the patients considered a surgical intervention anymore.

CONCLUSIONS

Patients after HELET show a decrease in pain and an improvement in performance after a 6-week training program with modified PD-AFO. The results suggest that the modified PDAFO is an effective alternative for a surgical approach.

IDEO energy-storing orthosis: Effects on lower extremity function and preservation

INTRODUCTION

The Intrepid Dynamic Exoskeletal Orthosis (IDEO) brace is a custom energy-storing orthosis design meant to improve gait, stability, and function after lower extremity injury or limb salvage. Early studies demonstrated the potential for the IDEO to improve functional performance, in conjunction with its paired return to run (RTR) rehabilitation program, compared to other brace types, and an impressively decreased rate of late amputation. The current study aimed to investigate these functional and revision outcomes from our institution to determine which patients may benefit most from IDEO bracing and what factors of the IDEO design and rehabilitation program are most important for improved outcomes after lower extremity trauma and/or loss of function.

METHODS

We performed a retrospective review of all patients treated with a IDEO style brace at a single military lower extremity trauma referral center between May 2003 and November 2017. We reviewed the medical records for initial diagnosis, post-orthotic rehabilitation program, IDEO use characteristics, pain, change in desire for amputation, and whether patient underwent eventual amputation.

RESULTS

We identified 213 patients with 222 lower extremities treated with IDEO brace. Of these, 76 limbs were treated for combat-related injuries. At one year follow-up, use status could not be determined for 37 extremities (16.7%). Of the 185 limbs with use data available, 116 (61.1%) continued regular brace use, and 37 (15.7%) reported intermittent use. Patients diagnosed with footdrop or weakness were more likely to continue use (OR 2.33, p=0.04), while patients with a previous fusion were less likely to continue use (OR 0.45, p=0.049). Undergoing any dedicated therapy increased chances of continued use (OR 3.37, p<0.001). At final follow-up, 16 patients (7.5%) underwent delayed lower extremity amputations following IDEO treatment. Overall, 27.2% of patients who initially desired amputation eventually underwent amputation despite IDEO brace use. Patients who underwent amputation reported higher pain levels (2 versus 5, p<0.001).

DISCUSSION

In select patients, the IDEO may decrease the desire for delayed amputation and permit higher levels of activity; however, its efficacy appears tied to the rehabilitative regimen, pain levels, and initial diagnosis. These findings should guide post-surgical extremity bracing prescriptions and expectations.

Military Service Members with Major Lower Extremity Fractures Return to Running with a Passive-dynamic Ankle-foot Orthosis: Comparison with a Normative Population

BACKGROUND

Lower extremity fractures represent a high percentage of reported injuries in the United States military and can devastate a service member's career. A passive dynamic ankle-foot orthosis (PD-AFO) with a specialized rehabilitation program was initially designed to treat military service members after complex battlefield lower extremity injuries, returning a select group of motivated individuals back to running. For high-demand users of the PD-AFO, the spatiotemporal gait parameters, agility, and quality of life is not fully understood with respect to uninjured runners.

QUESTIONS/PURPOSES

Do patients who sustained a lower extremity fracture using a PD-AFO with a specialized rehabilitation program differ from uninjured service members acting as controls, as measured by (1) time-distance and biomechanical parameters associated with running, (2) agility testing (using the Comprehensive High-level Activity Mobility Predictor performance test and Four Square Step Test), and (3) the Short Musculoskeletal Function Assessment score.

METHODS

We conducted a retrospective data analysis of a longitudinally collected data registry of patients using a PD-AFO from 2015 to 2017 at a single institution. The specific study cohort were patients with a unilateral lower extremity fracture who used the PD-AFO for running. Patients had to be fit with a PD-AFO, have completed rehabilitation, and have undergone a three-dimensional (3-D) running analysis at a self-selected speed at the completion of the program. Of the 90 patients who used the PD-AFO for various reasons, 10 male service members with lower extremity fractures who used a PD-AFO for running (median [range] age 29 years [22 to 41], height 1.8 meters [1.7 to 1.9], weight 91.6 kg [70 to 112]) were compared with 15 uninjured male runners in the military (median age 33 years [21 to 42], height 1.8 meters [1.7 to 1.9], weight 81.6 kg [71.2 to 98.9]). The uninjured runners were active-duty service members who voluntarily participated in a gait analysis at their own self-selected running speeds; to meet eligibility for inclusion as an uninjured control, the members had to be fit for full duty without any medical restrictions, and they had to be able to run 5 miles. The controls were then matched to the study group by age, weight, and height. The primary study outcome variables were the running time-distance parameters and frontal and sagittal plane kinematics of the trunk and pelvis during running. The Four Square Step Test, Comprehensive High-level Activity Mobility Predictor scores, and Short Musculoskeletal Function Assessment scores were analyzed for all groups as secondary outcomes. Nonparametric analyses were performed to determine differences between the two groups at p < 0.05.

RESULTS

For the primary outcome, patients with a PD-AFO exhibited no differences compared with uninjured runners in median (range) running velocity (3.9 meters/second [3.4 to 4.2] versus 4.1 meters/second [3.1 to 4.8], median difference 0.2; p = 0.69), cadence (179 steps/minute [169 to 186] versus 173 steps/minute [159 to 191], median difference 5.8; p = 0.43), stride length (2.6 meters [2.4 to 2.9] versus 2.8 meters [2.3 to 3.3], median difference 0.2; p = 0.23), or sagittal plane parameters such as peak pelvic tilt (24° [15° to 33°] versus 22° [14° to 28°], median difference 1.6°; p = 0.43) and trunk forward flexion (16.2° [7.3° to 23°) versus 15.4° [4.2° to 21°), median difference 0.8°; p > 0.99) with the numbers available. For the secondary outcomes, runners with a PD-AFO performed worse in Comprehensive High-level Activity Mobility Predictor performance testing than uninjured runners did, with their four scores demonstrating a median (range) single-limb stance of 35 seconds (32 to 58) versus 60 seconds (60 to 60) (median difference 25 seconds; p < 0.001), t-test result of 15 seconds (13 to 20) versus 13 seconds (10 to 14) (median difference 2 seconds; p < 0.001), and Illinois Agility Test result of 22 seconds (20 to 25) versus 18 seconds (16 to 20) (median difference 4; p < 0.001). Edgren side step test result of 20 meters (16 to 26) versus 24 meters (16 to 29) (median difference 4 meters; p = 0.11) and the Four Square Step Test of 5.5 seconds (4.1 to 7.2) versus 4.2 seconds (3.1 to 7.3) (median difference 1.3 seconds; p = 0.39) were not different between the groups with an effect size of 0.83 and 0.75, respectively.

CONCLUSION

The results of our study demonstrate that service members run with discernible differences in high-level mobility and demonstrate inferior self-reported patient functioning while having no differences in speed and biomechanics compared with their noninjured counterparts with the sample size available. This study is an early report on functional gains of highly motivated service members with major lower extremity injuries who use a PD-AFO and formalized therapy program to run.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Outcomes Following Severe Distal Tibial, Ankle, and/or Mid/Hindfoot Trauma: Comparison of Limb Salvage and Transtibial Amputation (OUTLET)

BACKGROUND

Selecting the best treatment for patients with severe terminal lower-limb injury remains a challenge. For some injuries, amputation may result in better outcomes than limb salvage. This study compared the outcomes of patients who underwent limb salvage with those that would have been achieved had they undergone amputation.

METHODS

This multicenter prospective observational study included patients 18 to 60 years of age in whom a Type-III pilon or IIIB or C ankle fracture, a Type-III talar or calcaneal fracture, or an open or closed blast/crush foot injury had been treated with limb salvage (n = 488) or amputation (n = 151) and followed for 18 months. The primary outcome was the Short Musculoskeletal Function Assessment (SMFA). Causal effect estimates of the improvement that amputation would have provided if it had been performed instead of limb salvage were calculated for the SMFA score, physical performance, pain, participation in vigorous activities, and return to work.

RESULTS

The patients who underwent limb salvage would have had small differences in most outcomes had they undergone amputation. The most notable difference was an improvement in the SMFA mobility score of 7 points (95% confidence interval [CI] = 2.0 to 10.7). Improvements were largest for pilon/ankle fractures and complex injury patterns.

CONCLUSIONS

Amputation should be considered a treatment option rather than a last resort for the most complex terminal lower-limb injuries.

LEVEL OF EVIDENCE

Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

Carbon Fiber-Based Twisted and Coiled Artificial Muscles (TCAMs) for Powered Ankle-Foot Orthoses

Ankle foot orthoses (AFOs) control the position and motion of the ankle, compensate for weakness, and correct deformities. AFOs can be classified as passive or powered. Powered AFOs overcome the limitations of passive AFOs by adapting their performance to meet a variety of requirements. However, the actuators currently used to power AFOs are typically heavy, bulky, expensive, or limited to laboratory settings. Thus, there is a strong need for lightweight, inexpensive, and flexible actuators for powering AFOs. In this technical brief, carbon fiber/silicone rubber (CF/SR) twisted and coiled artificial muscles (TCAMs) are proposed as novel actuators for powered AFOs. CF/SR TCAMs can lift to 12,600 times their weight with an input power of only 0.025 W cm-1 and are fabricated from inexpensive materials through a low-cost manufacturing process. Additionally, they can provide a specific work of 758 J kg-1 when an input voltage of 1.64 V cm-1 is applied. Mechanical characterization of CF/SR TCAMs in terms of length/tension, tension/velocity, and active-passive length/tension is presented, and results are compared with the performance of skeletal muscles. A gait analysis demonstrates that CF/SR TCAMs can provide the performance required to supplement lower limb musculature and replicate the gait cycle of a healthy subject. Therefore, the preliminary results provided in this brief are a stepping stone for a dynamic AFO powered by CF/SR TCAMs.

The effect of custom carbon ankle-foot orthosis alignment on roll-over shape and center of pressure velocity

BACKGROUND

Maintaining an optimal rolling of the foot over the ground is thought to increase the stability and efficiency of pathologic gait. Ankle-foot orthoses are often prescribed to improve gait mechanics in individuals with lower extremity injuries; however, their design may compromise how the foot rolls over the ground.

OBJECTIVES

The aim of this study was to investigate the effects of the sagittal plane ankle-foot orthosis alignment on roll-over shape and center of pressure velocity in individuals with lower limb reconstructions.

STUDY DESIGN

Randomized cross-over study with a control group comparison.

METHODS

In total, 12 individuals with lower limb reconstruction who used a custom carbon ankle-foot orthosis and 12 uninjured controls underwent gait analysis. Ankle-foot orthosis users were tested in their clinically-provided ankle-foot orthosis alignment, with an alignment that was 3° more plantarflexed, and with an alignment that was 3° more dorsiflexed. Components of roll-over shape and center of pressure velocity were calculated from heel strike on the ankle-foot orthosis limb to contralateral heel strike.

RESULTS

Roll-over shape radius was not affected by 3° changes to alignment and was not significantly different from controls. Aligning the ankle-foot orthosis in more dorsiflexion than clinically provided resulted in a smaller peak center of pressure velocity that occurred later in stance.

CONCLUSION

Individuals using custom carbon ankle-foot orthoses can accommodate 3° alterations in the dorsiflexion or plantarflexion alignment.

Health Outcomes Used to Determine Facets of Health-related Quality of Life for Post-9/11 Veterans Using Assistive Technology for A Combat-related Mobility Impairment: A Literature Review

INTRODUCTION

Novel rehabilitation methods, including distribution and adoption of assistive technology for lower extremity impairments, are becoming crucial to ensure positive quality of life in all individuals. The quality of life of post-9/11 combat veterans is not well understood, in comparison to research on other populations. The following essay describes a review on health outcomes used to determine health-related quality of life (HR-QoL) among combat-injured service members who require mobility-related assistive technology.

MATERIALS AND METHODS

Reviews pooled data from research on PubMed, EMBASE, CINAHL, and PsycINFO published after September 11, 2001, and included service members who sustained a mobility impairment because of involvement in a post-9/11 combat operation. Basic descriptors were extracted in addition to health outcomes used, which were then categorized and summarized by six domains for HR-QoL as defined by the World Health Organization.

RESULTS

This review found health outcomes that fit in the pain and discomfort, negative emotions, mobility, social relations, access to and quality of healthcare services, and religious/spiritual/personal beliefs subdomains. The categorized results detailed their application to track and model HR-QoL health states in those with mobility impairments using mobility-based assistive technology.

CONCLUSIONS

The research on combat-induced mobility impairments indicates assistive technology improves otherwise poor health states. The results model these domains and subdomains to determine overall HR-QoL and the quality of a healthcare intervention, though additional research is needed as only one study was identified to be experimental in design.

Custom Dynamic Orthoses and Physical Therapist Intervention for Bilateral Midfoot Amputation: A Case Report

OBJECTIVE

Partial foot amputation is often associated with decreased mobility and function. Recent advances in custom carbon-fiber dynamic ankle-foot orthoses (CDOs) have improved gait, pain, and function following musculoskeletal trauma and can benefit individuals with partial foot amputation. However, limited information is available related to CDO use outside the military. The purpose of this case report is to describe the course of care and outcomes of a civilian provided with CDOs after bilateral transmetatarsal amputation.

CASE DESCRIPTION

A 72-year-old man had a blood-borne bacterial infection (septicemia) of unknown origin at 68 years of age, developed limb-threatening necrosis of the hands and feet, and received bilateral transmetatarsal amputations with skin grafting. The patient initially used foam toe fillers and cushioned shoes but was functionally limited and experienced recurrent ulceration. He was fitted with bilateral CDOs 39 months after amputation and completed device-specific training with a physical therapist.

RESULTS

After 1 week with the CDOs, ankle range of motion during gait was reduced, but greater than 40% increases were observed in bilateral ankle plantarflexor moments and ankle plantarflexion push-off power compared with the toe fillers. With additional therapist-directed training focused on gait and activity performance, ankle plantarflexor moments and plantarflexion push-off power further increased when compared with results after 1 week of CDO use. The patient reported marked improvement in quality of life with the CDOs due to improved walking ability on level and uneven terrain, marked improvement in confidence, and reduced pain.

CONCLUSION

This case reflects the lessons learned and outcomes of a civilian using bilateral CDOs after bilateral transmetatarsal amputation and with poor skin quality. The results from this case study suggest that carbon-fiber CDOs and focused training by a physical therapist can result in improved gait biomechanics, mobility, and quality of life.

How New Technology Is Improving Physical Therapy

PURPOSE OF REVIEW

As rehabilitation patient volume across the age spectrum increases and reimbursement rates decrease, clinicians are forced to produce favorable outcomes with limited resources and time. The purpose of this review is to highlight new technologies being utilized to improve standardization and outcomes for patients rehabilitating orthopedic injuries ranging from sports medicine to trauma to joint arthroplasty.

RECENT FINDINGS

A proliferation of new technologies in rehabilitation has recently occurred with the hope of improved outcomes, better patient compliance and safety, and return to athletic performance. These include technologies applied directly to the patient such as exoskeletons and instrumented insoles to extrinsic applications such as biofeedback and personalized reference charts. Well-structured randomized trials are ongoing centered around the efficacy and safety of these new technologies to help guide clinical necessity and appropriate application. We present a range of new technologies that may assist a diverse population of orthopedic conditions. Many of these interventions are already supported by level 1 evidence and appear safe and feasible for most clinical settings.

Advanced Functional Bracing in Lower Extremity Trauma: Bracing to Improve Function

There are many bracing options for patients with functional limitations of the lower extremity following trauma. The first question that the provider must ask when evaluating a patient with a foot and ankle functional limitation because of weakness or pain is, "what are the patient's expectations?" One option for the patient who desires to return to a higher level of function is a novel, custom dynamic orthosis (CDO) that, when coupled with an advanced rehabilitation program, has improved outcomes in patients following lower extremity trauma who have plateaued after traditional rehabilitation pathways. Although this CDO and rehabilitation program has demonstrated success following lower extremity trauma in heterogenous patient populations, research is ongoing to identify both ideal referral diagnoses or injury characteristics, and to further optimize outcomes with the use of the CDO.

A Review on the Control of the Mechanical Properties of Ankle Foot Orthosis for Gait Assistance

In the past decade, advanced technologies in robotics have been explored to enhance the rehabilitation of post-stroke patients. Previous works have shown that gait assistance for post-stroke patients can be provided through the use of robotics technology in ancillary equipment, such as Ankle Foot Orthosis (AFO). An AFO is usually used to assist patients with spasticity or foot drop problems. There are several types of AFOs, depending on the flexibility of the joint, such as rigid, flexible rigid, and articulated AFOs. A rigid AFO has a fixed joint, and a flexible rigid AFO has a more flexible joint, while the articulated AFO has a freely rotating ankle joint, where the mechanical properties of the AFO are more controllable compared to the other two types of AFOs. This paper reviews the control of the mechanical properties of existing AFOs for gait assistance in post-stroke patients. Several aspects that affect the control of the mechanical properties of an AFO, such as the controller input, number of gait phases, controller output reference, and controller performance evaluation are discussed and compared. Thus, this paper will be of interest to AFO researchers or developers who would like to design their own AFOs with the most suitable mechanical properties based on their application. The controller input and the number of gait phases are discussed first. Then, the discussion moves forward to the methods of estimating the controller output reference, which is the main focus of this study. Based on the estimation method, the gait control strategies can be classified into subject-oriented estimations and phase-oriented estimations. Finally, suggestions for future studies are addressed, one of which is the application of the adaptive controller output reference to maximize the benefits of the AFO to users.