A national study of Veterans with major upper limb amputation: Survey methods, participants, and summary findings

Patient-reported significant disability after major traumatic upper extremity amputation

The aims of this study were to record patient-reported outcomes of treatment of proximal upper extremity amputation injuries and subsequent return to work. A consecutive cohort of 38 patients with a traumatic amputation at or proximal to the carpus had been treated with a replantation or revision (completion) amputation in Tampere University Hospital between 2009 and 2019, and 31 of them participated in this study. The primary outcome was the Disabilities of the Arm, Shoulder and Hand Outcome Measure (DASH). Patients reported significant disability indicated by DASH score after replantation (median 30; interquartile range [IQR] 21-47) and revision (completion) amputation (median 33; IQR 16-52). Most patients had cold intolerance and reported low hand function and aesthetics scores. Out of 17 working patients, 10 did not return to their previous work. Our study demonstrates the influence of major upper extremity amputation on daily life activities, even after a successful replantation.Level of evidence: IV.

Prosthesis usability experience is associated with extent of upper limb prosthesis adoption: A Structural Equation Modeling (SEM) analysis

Factors associated with upper limb prosthesis adoption are not well understood. In this study, we explored how prosthesis usability experience relates to the extent of prosthesis adoption through the development of a structural equation model (SEM). First, items related to prosthesis usability were developed and refined using cognitive testing and pilot testing and employed in a survey of 402 prosthesis users (mean age 61.7 (sd 14.4), 77.1% Veterans). The SEM examined two unidimensional latent constructs: Prosthesis Usability Experience and Prosthesis Adoption-and each had multiple measured indicators. SEMs tested direct as well as moderating and mediating effects between the latent constructs and covariates related to demographics and prosthesis type. SEM found a significant positive association between Prosthesis Usability Experience and Extent of Prosthesis Adoption. Several covariates had direct effects on prosthesis adoption: 1) Extent of Prosthesis Adoption was lower for those with transhumeral and shoulder amputation, and higher for those with bilateral amputation, compared to the reference group with unilateral transradial amputation and 2) Myoelectric multiple degree of freedom (multi-DOF) prosthesis use was associated with lower Extent of Prosthesis Adoption, compared to body-powered prosthesis use. Myoelectric multi-DOF use also modified the effect of Prosthesis Usability Experience on Extent of Prosthesis Adoption. For those with bilateral ULA, the strength of the relationship between Prosthesis Usability Experience and Extent of Prosthesis Adoption was reduced. Findings suggest that in order to increase prosthesis adoption, prosthetics developers and rehabilitation providers should focus on implementing strategies to improve prosthesis usability experience. New Prosthesis Usability Experience measures could be used to identify persons at greater risk for poor prosthesis adoption and target interventions to increase prosthesis use.

Targeted muscle reinnervation in bionic upper limb reconstruction: current status and future directions

Selective nerve transfers are used in the setting of upper limb amputation to improve myoelectric prosthesis control. This surgical concept is referred to as targeted muscle reinnervation (TMR) and describes the rerouting of the major nerves of the arm onto the motor branches of the residual limb musculature. Aside from providing additional myosignals for prosthetic control, TMR can treat and prevent neuroma pain and possibly also phantom limb pain. This article reviews the history and current applications of TMR in upper limb amputation, with a focus on practical considerations. It further explores and identifies technological innovations to improve the man-machine interface in amputation care, particularly regarding implantable interfaces, such as muscle electrodes and osseointegration. Finally, future clinical directions and possible scientific avenues in this field are presented and critically discussed.

Biomimetic versus arbitrary motor control strategies for bionic hand skill learning

A long-standing engineering ambition has been to design anthropomorphic bionic limbs: devices that look like and are controlled in the same way as the biological body (biomimetic). The untested assumption is that biomimetic motor control enhances device embodiment, learning, generalization and automaticity. To test this, we compared biomimetic and non-biomimetic control strategies for non-disabled participants when learning to control a wearable myoelectric bionic hand operated by an eight-channel electromyography pattern-recognition system. We compared motor learning across days and behavioural tasks for two training groups: biomimetic (mimicking the desired bionic hand gesture with biological hand) and arbitrary control (mapping an unrelated biological hand gesture with the desired bionic gesture). For both trained groups, training improved bionic limb control, reduced cognitive reliance and increased embodiment over the bionic hand. Biomimetic users had more intuitive and faster control early in training. Arbitrary users matched biomimetic performance later in training. Furthermore, arbitrary users showed increased generalization to a new control strategy. Collectively, our findings suggest that biomimetic and arbitrary control strategies provide different benefits. The optimal strategy is probably not strictly biomimetic, but rather a flexible strategy within the biomimetic-to-arbitrary spectrum, depending on the user, available training opportunities and user requirements.

Developing a Novel Prosthetic Hand with Wireless Wearable Sensor Technology Based on User Perspectives: A Pilot Study

Myoelectric hands are beneficial tools in the daily activities of people with upper-limb deficiencies. Because traditional myoelectric hands rely on detecting muscle activity in residual limbs, they are not suitable for individuals with short stumps or paralyzed limbs. Therefore, we developed a novel electric prosthetic hand that functions without myoelectricity, utilizing wearable wireless sensor technology for control. As a preliminary evaluation, our prototype hand with wireless button sensors was compared with a conventional myoelectric hand (Ottobock). Ten healthy therapists were enrolled in this study. The hands were fixed to their forearms, myoelectric hand muscle activity sensors were attached to the wrist extensor and flexor muscles, and wireless button sensors for the prostheses were attached to each user's trunk. Clinical evaluations were performed using the Simple Test for Evaluating Hand Function and the Action Research Arm Test. The fatigue degree was evaluated using the modified Borg scale before and after the tests. While no statistically significant differences were observed between the two hands across the tests, the change in the Borg scale was notably smaller for our prosthetic hand (p = 0.045). Compared with the Ottobock hand, the proposed hand prosthesis has potential for widespread applications in people with upper-limb deficiencies.

Long-term burden of war injuries among civilians in LMICs: case of the July 2006 war in Lebanon

Introduction

Lebanon, a country located on the eastern shore of the Mediterranean Sea, is one of the world's smaller sovereign states. In the past few decades, Lebanon endured a perpetual political turmoil and several armed conflicts. July 12, 2006, marked the start of a one-month war in Lebanon, which resulted in thousands of casualties. Little is known about the long-term consequences of war injuries inflicted on civilians during the July 2006 war.

Methods

The objectives of this paper were to identify and evaluate: 1- civilians' access to healthcare and medicine under conditions of war; 2- the long-term socioeconomic burden on injured civilians; and 3- their quality of life more than a decade post-war. We adopted a mixed-method research design with an emphasis on the qualitative component. We conducted interviews with patients, collected clinical and financial data from hospital medical records, and administered a self-rated health questionnaire, the EQ-5D-5L. Simple descriptive statistics were calculated using Excel. NVivo 12® was used for data management and thematic analysis.

Results

We conducted 25 interviews. Injured civilians were mostly males, average age of 27. The most common mechanism of injury was blast injury. Most patients underwent multiple surgeries as well as revision surgeries. The thematic analysis revealed three themes: 1- recall of the time of the incident, the thousand miles journey, and patients' access to services; 2- post-trauma sequelae and services; and 3- long-term impact. Patients described the long-term burden including chronic pain, poor mobility, anxiety or depression, and limited activities of daily living.

Discussion

Civilians injured during the July 2006 war described the traumatising events they endured during the war and the limited access to medical care during and post-war. Up until this study was conducted, affected civilians were still experiencing physical, psychological, and financial sequelae. Acknowledging the limitations of this study, which include a small sample size and recall bias, the findings underscore the necessity for the expansion of services catering to civilians injured during wartime.

Prosthesis nonuse and discontinuation in United States veterans with major limb amputation: Results of a national survey

BACKGROUND

Prosthesis use in persons with amputation can improve mobility and functional independence. Better understanding of the reasons for and outcomes associated with prosthesis nonuse is important to optimize function and long-term health in persons with amputation.

OBJECTIVES

Study objectives were to describe the rate, reasons for, and factors associated with never using or discontinuing prosthesis use in United States (US) veterans with amputation.

STUDY DESIGN

Cross-sectional study design.

METHODS

The study used an online survey to assess prosthesis use and satisfaction in veterans with upper-limb and lower-limb amputation. Survey participation invitations were distributed by email, text message, and mail to 46,613 potential participants.

RESULTS

The survey response rate was 11.4%. After exclusions, an analytic sample of 3,959 respondents with a major limb amputation was identified. The sample was 96.4% male; 78.3% White, with mean age of 66.9; and mean of 18.2 years since amputation. The rate of never using a prosthesis was 8.2%, and the rate of prosthesis discontinuation was 10.5%. Functionality (62.0%), undesirable prosthesis characteristics (56.9%), and comfort (53.4%) were the most common reasons for discontinuation. After controlling for the amputation subgroup, the odds of prosthesis discontinuation were higher for those with unilateral upper-limb amputation, female gender, White race (compared with Black race), diabetes, above-knee amputation, and lower prosthesis satisfaction. Prosthesis satisfaction and quality of life were highest for current prosthesis users.

CONCLUSIONS

This study adds new understanding regarding the rate and reasons for prosthesis nonuse in veterans and highlights the important relationship between prosthesis discontinuation and prosthesis satisfaction, quality of life, and satisfaction with life.

Functionally Adaptive Myosite Selection Using High-Density sEMG for Upper Limb Myoelectric Prostheses

OBJECTIVE

Our study defines a novel electrode placement method called Functionally Adaptive Myosite Selection (FAMS), as a tool for rapid and effective electrode placement during prosthesis fitting. We demonstrate a method for determining electrode placement that is adaptable towards individual patient anatomy and desired functional outcomes, agnostic to the type of classification model used, and provides insight into expected classifier performance without training multiple models.

METHODS

FAMS relies on a separability metric to rapidly predict classifier performance during prosthesis fitting.

RESULTS

The results show a predictable relationship between the FAMS metric and classifier accuracy (3.45%SE), allowing estimation of control performance with any given set of electrodes. Electrode configurations selected using the FAMS metric show improved control performance ( ) for target electrode counts compared to established methods when using an ANN classifier, and equivalent performance ( R2 ≥ .96) to previous top-performing methods on an LDA classifier, with faster convergence ( ). We used the FAMS method to determine electrode placement for two amputee subjects by using the heuristic to search through possible sets, and checking for saturation in performance vs electrode count. The resulting configurations that averaged 95.8% of the highest possible classification performance using a mean 25 number of electrodes (19.5% of the available sites).

SIGNIFICANCE

FAMS can be used to rapidly approximate the tradeoffs between increased electrode count and classifier performance, a useful tool during prosthesis fitting.

Prevalence and predictors of unmet need for upper limb prostheses: An observational cohort study

Introduction

No prior studies have examined the prevalence of unmet prosthesis need among prosthesis nonusers.

Objectives

The aim of this study was to describe the prevalence of unmet need for an upper-limb prosthesis and identify independent covariates associated with unmet need for a prosthesis.

Study Design

This study is a telephone survey of 742 persons with upper-limb amputation (ULA).

Methods

Differences between users and nonusers and between nonusers with and without an unmet need were compared statistically. Covariates associated with unmet need P ≤ 0.2 in bivariate analyses were included in a multivariate logistic regression model predicting unmet need.

Results

Odds of unmet need were higher for those who stopped using a prosthesis within the past year compared with 20 years or more ago (odds ratio [OR], 4.30; 95% confidence interval [CI], 1.28–14.51) and those on disability (OR, 4.01; 95% CI, 0.95–16.85). Odds of unmet need were lower for those with higher upper-limb function scores (OR, 0.94; 95% CI, 0.96–1.00), who were unemployed versus employed/student (OR, 0.15; 95% CI, 0.02–0.98), and those who had abandoned a prior prosthesis because it was “too much fuss” (OR, 0.41; 95% CI, 0.18–0.92).

Conclusions

Unmet need was prevalent, impacting approximately 50% of persons with upper-limb amputation who were not using a device and 14% who reported never having used a prosthesis. Independent correlates of greater unmet included worse upper-limb function, prosthesis use within the prior year, and disability status. Correlates of lesser unmet need included being unemployed and having abandoned a prosthesis because it was perceived as an undue burden. Further studies are needed to understand barriers to prosthesis use among nonusers with an unmet need.

Clinical Relevance

Persons with ULA who do not use a prosthesis should be reevaluated regularly to identify unmet needs. Our findings suggest recent prosthesis users, those with poorer upper-limb function, and those who are employed or on disability are more likely to have unmet needs.

Shoulder complaints and incidence of shoulder pathologies after contralateral major amputation in the mid and long-term

INTRODUCTION

Amputations of the upper extremity are rare but present a life-altering event that is accompanied with considerable restrictions for the affected patients. Even with functional prosthesis, tasks of the amputated limb are usually transferred to the unaffected arm which could result in complaints of the unaffected shoulder in the mid and long term. We therefore aimed to investigate musculoskeletal pain and morphological degenerative changes of the shoulder following a contralateral amputation.

MATERIALS AND METHODS

We included all patients with a major amputation treated at our institution with a minimum of three years since the amputation. All patients received an MRI of both shoulders and were investigated using validated scores for the upper extremity and physical activity (SSV, ASES, DASH, GPAQ, SF-36). Results of the MRIs were investigated for morphological changes by two blinded investigators comparing the side of the amputation and the unharmed upper extremity and results were correlated to the time since amputation and their physical activity.

RESULTS

A total of 20 patients with a mean age of 56 ± 19.9 years (range, 23-82 years) could be included in the study. The mean time since the amputation was 26.3 ± 19 years (range, 3-73 years). On the unharmed upper extremity, the mean SSV was 61.9 ± 24.6, the mean ASES-Score 54.5 ± 20.3, the Constant-score of 63.7 ± 40.4 and a DASH-score of 47.6 ± 23.8. The MRI of the unharmed shoulder showed significant more full-thickness rotator cuff tears and joint effusion compared to the side of the amputation. Significant differences in the degree of a glenohumeral arthritis, AC-joint arthritis, or partial rotator cuff tears could not be found between shoulders.

CONCLUSION

Amputations of the upper extremity are associated with a high disability of the unharmed upper extremity and more full thickness rotator cuff tears compared to the side of the amputation. However, the small number of patients and rotator cuff injuries should be kept in mind when interpreting the data.

LEVEL OF EVIDENCE

IV (retrospective case series).

Satisfaction of individuals with partial-hand amputations after they were fitted with cosmetic silicone prostheses

BACKGROUND

Partial-hand amputations are the most common level of upper-limb amputations which can lead to cosmetic and functional problems. Partial-hand amputations can be acquired or congenital. Cosmetic silicone prostheses are used in the management of partial-hand amputation; however, a literature review shows that most of the studies are on the fabrication of prosthesis, and data remain deficient on the satisfaction of users with silicone prostheses.

OBJECTIVES

To assess the satisfaction of individuals after they were fitted with cosmetic silicone prostheses for partial-hand amputations.

STUDY DESIGN

Cross-sectional study.

METHODS

Fifty-four participants with partial-hand amputations and who received cosmetic silicone prostheses participated in the survey using the validated Arabic version of the Client Satisfaction with Device (CSD-Ar).

RESULTS

Nearly half of the participants were using their silicone prosthesis daily. Most of the patients reported satisfaction with durability and donning, whereas most of the patients were dissatisfied with comfort. The mean of CSD-Ar total score was 16.8 ± 4.7 of 32. The CSD-Ar total score was significantly associated with the side of amputation ( p -value = 0.014) and usage of prosthesis ( p -value < 0.001).

CONCLUSION

The satisfaction of individuals with partial-hand amputations can be enhanced by fitting them with cosmetic silicone prostheses. However, these prostheses should meet certain criteria including fitting, weight, comfort, donning, appearance, durability, skin abrasion and irritation, and pain. Individuals' expectations and concerns should be considered as well.

Evaluating the effect of non-invasive force feedback on prosthetic grasp force modulation in participants with and without limb loss

Grasping an object is one of the most common and complex actions performed by humans. The human brain can adapt and update the grasp dynamics through information received from sensory feedback. Prosthetic hands can assist with the mechanical performance of grasping, however currently commercially available prostheses do not address the disruption of the sensory feedback loop. Providing feedback about a prosthetic hand's grasp force magnitude is a top priority for those with limb loss. This study tested a wearable haptic system, i.e., the Clenching Upper-Limb Force Feedback device (CUFF), which was integrated with a novel robotic hand (The SoftHand Pro). The SoftHand Pro was controlled with myoelectrics of the forearm muscles. Five participants with limb loss and nineteen able-bodied participants completed a constrained grasping task (with and without feedback) which required modulation of the grasp to reach a target force. This task was performed while depriving participants of incidental sensory sources (vision and hearing were significantly limited with glasses and headphones). The data were analyzed with Functional Principal Component Analysis (fPCA). CUFF feedback improved grasp precision for participants with limb loss who typically use body-powered prostheses as well as a sub-set of able-bodied participants. Further testing, that is more functional and allows participants to use all sensory sources, is needed to determine if CUFF feedback can accelerate mastery of myoelectric control or would benefit specific patient sub-groups.

Flexible Magnetic Skin Sensor Array for Torsion Perception

Prosthetic hands help upper limb amputees and people who were born without hands. Currently, these prostheses are rather rudimentary and do not provide adequate sensing capabilities compared to a human hand. People use their natural hands to perceive complex tactile phenomena such as shear and torsion using thousands of mechanoreceptors in their fingertips. The capability to detect torsional loads at the fingertips is a notable gap in prosthetic hand sensation. Flexible tactile sensors are a promising new technology that would be ideal for prosthetic hands since they allow for stretching and movement like human skin without damage to the sensor. Therefore, the purpose of this study is to determine whether a flexible magnetic sensor array combined with an artificial neural network (ANN) can detect and classify torsion. The flexible magnetic sensor is designed as a 3×3 array of magnets embedded in a stretchable elastomer which are situated atop a corresponding array of Hall effect sensors. Torques applied to the soft magnetic skin caused displacement of the magnetic fields that were perceived by the nine Hall effect sensors. In this study, ten different values of torque were applied to the flexible magnetic sensor array using a robotic arm to ensure consistency. Data were used to train an ANN to classify the applied torques. The ANN was trained ten times and could predict the applied torque with an average training classification accuracy of 97.48% ± 0.33%. Given the results of this study, this novel sensor design could enable more refined sensations of touch for people who use prosthetic hands.

Comparison of patient-reported and functional outcomes after transition from traditional upper limb prosthetics to multiarticulating hands in the user with a unilateral transradial amputation

BACKGROUND

Multiarticulating hands (MAHs) have been commercially available for over 15 years. Despite this, their cost remains significantly higher than traditional electric hands, and they are not routinely available in many countries. The Scottish Specialist Prosthetic Service within the National Health Service has been prescribing MAHs since 2014. However, the benefits of MAHs provided in clinical settings are not well known.

OBJECTIVES

This study aimed to compare patient-reported and functional measures in unilateral transradial prosthetic users transitioning from a body-powered or traditional myoelectric prosthesis to a MAH.

STUDY DESIGN

This was a retrospective cohort analysis of individuals with a unilateral transradial amputation provided with a MAH.

METHODS

Of 38 users provided with MAHs, 20 had complete data sets of patient-reported and functional measures before and 6 months after provision. These included Disabilities of the Arm, Shoulder, and Hand; Southampton Hand Assessment Procedure Index of Function; health-related quality of life (EQ-5D-5L Health Index); Trinity Amputation and Prosthesis Experience Scales satisfaction; and Box and Block Test.

RESULTS

The mean age was 44 years (SD 16) (n = 20), and 75% were male. There were an 8-unit mean reduction in the Disabilities of the Arm, Shoulder, and Hand ( P = .01) and a 9.5-unit improvement in the Southampton Hand Assessment Procedure IOF ( P = .007) at 6 months after provision. Health-related quality of life did not change ( P = .581). Users reported a four-point improvement in their Trinity Amputation and Prosthesis Experience Scales ( P = .004) and transferred 3.3 blocks more completing the Box and Block Test ( P = .001).

CONCLUSIONS

The evidence clearly supports continued provision of MAHs to this group of moderate users: the more function the user achieves, the less of a disability they perceive to have.

Soft-Sensor System for Grasp Type Recognition in Underactuated Hand Prostheses

This paper presents the development of an intelligent soft-sensor system to add haptic perception to the underactuated hand prosthesis PrHand. Two sensors based on optical fiber were constructed, one for finger joint angles and the other for fingertips' contact force. Three sensor fabrications were tested for the angle sensor by axially rotating the sensors in four positions. The configuration with the most similar response in the four rotations was chosen. The chosen sensors presented a polynomial response with R2 higher than 92%. The tactile force sensors tracked the force made over the objects. Almost all sensors presented a polynomial response with R2 higher than 94%. The system monitored the prosthesis activity by recognizing grasp types. Six machine learning algorithms were tested: linear regression, k-nearest neighbor, support vector machine, decision tree, k-means clustering, and hierarchical clustering. To validate the algorithms, a k-fold test was used with a k = 10, and the accuracy result for k-nearest neighbor was 98.5%, while that for decision tree was 93.3%, enabling the classification of the eight grip types.

Measurement of Functional Use in Upper Extremity Prosthetic Devices Using Wearable Sensors and Machine Learning

Trials for therapies after an upper limb amputation (ULA) require a focus on the real-world use of the upper limb prosthesis. In this paper, we extend a novel method for identifying upper extremity functional and nonfunctional use to a new patient population: upper limb amputees. We videotaped five amputees and 10 controls performing a series of minimally structured activities while wearing sensors on both wrists that measured linear acceleration and angular velocity. The video data was annotated to provide ground truth for annotating the sensor data. Two different analysis methods were used: one that used fixed-size data chunks to create features to train a Random Forest classifier and one that used variable-size data chunks. For the amputees, the fixed-size data chunk method yielded good results, with 82.7% median accuracy (range of 79.3-85.8) on the 10-fold cross-validation intra-subject test and 69.8% in the leave-one-out inter-subject test (range of 61.4-72.8). The variable-size data method did not improve classifier accuracy compared to the fixed-size method. Our method shows promise for inexpensive and objective quantification of functional upper extremity (UE) use in amputees and furthers the case for use of this method in assessing the impact of UE rehabilitative treatments.

Should bionic limb control mimic the human body? Impact of control strategy on bionic hand skill learning

A longstanding engineering ambition has been to design anthropomorphic bionic limbs: devices that look like and are controlled in the same way as the biological body (biomimetic). The untested assumption is that biomimetic motor control enhances device embodiment, learning, generalization, and automaticity. To test this, we compared biomimetic and non-biomimetic control strategies for able-bodied participants when learning to operate a wearable myoelectric bionic hand. We compared motor learning across days and behavioural tasks for two training groups: Biomimetic (mimicking the desired bionic hand gesture with biological hand) and Arbitrary control (mapping an unrelated biological hand gesture with the desired bionic gesture). For both trained groups, training improved bionic limb control, reduced cognitive reliance, and increased embodiment over the bionic hand. Biomimetic users had more intuitive and faster control early in training. Arbitrary users matched biomimetic performance later in training. Further, arbitrary users showed increased generalization to a novel control strategy. Collectively, our findings suggest that biomimetic and arbitrary control strategies provide different benefits. The optimal strategy is likely not strictly biomimetic, but rather a flexible strategy within the biomimetic to arbitrary spectrum, depending on the user, available training opportunities and user requirements.

Factors influencing perceived function in the upper limb prosthesis user population

BACKGROUND

Patient-reported outcomes (PROs) can be used to evaluate perceived capacity of an individual in executing tasks in a natural environment with their prosthetic device. According to the World Health Organization International Classification of Health, Functioning, and Disability (ICF) models, there may be specific factors of a person, factors of assistive prosthetic technology, or factors related to the health condition or body function that affect their functioning and disability. However, an understanding of factors affecting an upper limb prosthesis user's perception of their ability to execute tasks in a natural environment is not well established.

OBJECTIVE

To use the ICF model to identify which health condition-related, body function, environmental, and personal factors influence activity as measured by perceived function in the upper limb prosthesis user population.

DESIGN

Quantitative clinical descriptive study.

SETTING

Clinical offices within outpatient private practice (removed for blinding).

PARTICIPANTS

A sample of 101 participants with upper limb amputation who use a prosthetic device and were undergoing a prosthesis fitting process.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

PROs on pain with/without a prosthesis, satisfaction, and perceived function derived from the Comprehensive Arm Prosthesis and Rehabilitation Outcomes Questionnaire.

RESULTS

Model coefficients indicate that with a unit increase in satisfaction (p < .001) and pain (p = .031) scores (with higher pain scores signifying less pain), the mean of perceived function increases by 0.66 and 0.47 units, respectively. Conversely, for individuals with elbow disarticulation, transhumeral, shoulder disarticulation, and interscapulothoracic amputations, the mean of perceived function decreases by 22.02 units (p = .006).

CONCLUSIONS

Based on our sample, perceived function is significantly associated with satisfaction, pain, and amputation level. These findings could potentially help to inform initial clinical approach and targeted outcomes for patients based on these factors.

Measuring Satisfaction With Upper Limb Prostheses: Orthotics and Prosthetics User Survey Revision That Includes Issues of Concern to Women

OBJECTIVE

To (1) modify the Orthotics and Prosthetics User Survey (OPUS) Client Satisfaction with Device (CSD) instrument to incorporate issues of concern to women and (2) evaluate measure's structural and concurrent validity and reliability in persons with upper limb amputation (ULA).

DESIGN

Cross-sectional survey study with retest after 2 weeks. Exploratory factor analysis (EFA), confirmatory factor analysis (CFA), and Rasch analyses were used to select items and examine differential item functioning, range of coverage, and person and item reliability. Test-retest reliability was evaluated with intraclass correlation coefficients. Pearson correlations were used to estimate associations with other prosthesis satisfaction measures.

SETTING

Telephone administered survey.

PARTICIPANTS

Convenience sample of 468 participants in the US (N=468; 19.9% women) with ULA, including a 50-person retest subsample (4% female).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Modified OPUS CSD.

RESULTS

EFA suggested 3 subscales: Comfort, Appearance, and Utility. CFA found acceptable model fit. After dropping items with poor fit and high pairwise correlations in Rasch partial credit models, CFA model fit indices were acceptable (comparative fit index=0.959, Tucker-Lewis Index=0.954, root mean square error of approximation=0.082). Rasch person reliability was 0.62 (Utility), 0.77 (Appearance), and 0.82 (Comfort). Cronbach α was 0.81, 87, and 0.71 for Comfort and Appearance, and Utility subscales, respectively. Correlations between the modified CSD, the original CSD, and the Trinity Amputation and Prosthesis Experience Satisfaction Scale were 0.54-0.94.

CONCLUSIONS

We identified 3 subscales: Comfort (6 items), Appearance (8 items), and Utility (4 items) with 7 new items identified as important to women. The subscales demonstrate evidence of sound concurrent structural and test-retest reliability and concurrent validity. The Appearance and Comfort subscales have good reliability for group-level use in clinical and research applications, whereas the Utility subscale had poor to fair person reliability but excellent item reliability.

Understanding Implications of Residual Limb Length, Strength, and Range-of-Motion Impairments of Veterans With Upper Limb Amputation

OBJECTIVE

The aim of the study was to describe and quantify the relationship between limb impairment variables to key functional outcomes.

DESIGN

This was an observational study of 107 participants with unilateral above/at-elbow or below-elbow/wrist amputation. Demographics, prosthesis characteristics, residual limb length, and prevalence of passive range-of-motion restrictions, and strength impairments were described. Correlations between impairment variables were estimated. Linear regressions examined associations between impairment variables and activity performance, health-related quality of life, disability, and prosthesis satisfaction.

RESULTS

Prevalence of short/very short below- and above-elbow residua was 25.7% and 12.5%, respectively. Shorter below-elbow/wrist residual limb length was correlated with elbow flexion weakness (r = 0.30) and prevalence of passive range of motion (r = 0.25). Shoulder prevalence of passive range-of-motion restrictions were correlated with shoulder (r = 0.27-0.51) and elbow weakness (r = 0.25-0.46). In regressions, activity performance was worse for those with shoulder flexion prevalence of passive range-of-motion restrictions (B = -5.0, P = 0.03) and better for those with flexion restrictions (B = 3.3, P = 0.04) compared with normal prevalence of passive range of motion. Prosthetic satisfaction was lower for those with limited elbow prevalence of passive range of motion.

CONCLUSIONS

Short below-elbow residual limb length was correlated with impairment of elbow flexion strength and prevalence of passive range of motion. Prevalence of passive range-of-motion restrictions were most prevalent at the shoulder and were strongly correlated with weakness in the same planes of motion. Few significant associations were found between impairment variables and outcomes.

Making sense of phantom limb pain

Phantom limb pain (PLP) impacts the majority of individuals who undergo limb amputation. The PLP experience is highly heterogenous in its quality, intensity, frequency and severity. This heterogeneity, combined with the low prevalence of amputation in the general population, has made it difficult to accumulate reliable data on PLP. Consequently, we lack consensus on PLP mechanisms, as well as effective treatment options. However, the wealth of new PLP research, over the past decade, provides a unique opportunity to re-evaluate some of the core assumptions underlying what we know about PLP and the rationale behind PLP treatments. The goal of this review is to help generate consensus in the field on how best to research PLP, from phenomenology to treatment. We highlight conceptual and methodological challenges in studying PLP, which have hindered progress on the topic and spawned disagreement in the field, and offer potential solutions to overcome these challenges. Our hope is that a constructive evaluation of the foundational knowledge underlying PLP research practices will enable more informed decisions when testing the efficacy of existing interventions and will guide the development of the next generation of PLP treatments.

A Psychosocial Adjustment Measure for Persons With Upper Limb Amputation

BACKGROUND

Measurement of psychosocial adjustment after upper limb amputation (ULA) could be helpful in identifying persons who may benefit from interventions, such as psychotherapy and/or support groups. However, available measures of psychosocial adjustment after limb loss are currently designed for prosthetic users only.

OBJECTIVE

To create a measure of psychosocial adjustment for persons with ULA that could be completed by individuals regardless of whether a prosthesis is use.

METHODOLOGY

We modified items from an existing Trinity Amputation and Prosthesis Experience Survey (TAPES) measure and generated new items pertinent to persons who did not use a prosthesis. Item content was refined through cognitive interviewing and pilot testing. A telephone survey of 727 persons with major ULA (63.6% male, mean age of 54.4) was conducted after pilot-testing. After exploratory and confirmatory factor analyses (EFA and CFA), Rasch analyses were used to evaluate response categories, item fit and differential item functioning (DIF). Item-person maps, score distributions, and person and item reliability were examined. Test-retest reliability was evaluated in a 50-person subsample.

FINDINGS

EFA and CFA indicated a two-factor solution. Rasch analyses resulted in a 7-item Adjustment to Limitation subscale (CFI=0.96, TLI=0.95, RMSEA=0.128) and a 9-item Work and Independence subscale (CFI=0.935, TLI=0.913, RMSEA=0.193). Cronbach alpha and ICC were 0.82 and 0.63 for the Adjustment to Limitation subscale and 0.90 and 0.80 for the Work and Independence subscale, respectively.

CONCLUSIONS

This study developed the Psychosocial Adjustment to Amputation measure, which contains two subscales: 1) Adjustment to Limitation and 2) Work and Independence. The measure has sound structural validity, good person and item reliability, and moderate to good test-retest reliability.

Multichannel haptic feedback unlocks prosthetic hand dexterity

Loss of tactile sensations is a major roadblock preventing upper limb-absent people from multitasking or using the full dexterity of their prosthetic hands. With current myoelectric prosthetic hands, limb-absent people can only control one grasp function at a time even though modern artificial hands are mechanically capable of individual control of all five digits. In this paper, we investigated whether people could precisely control the grip forces applied to two different objects grasped simultaneously with a dexterous artificial hand. Toward that end, we developed a novel multichannel wearable soft robotic armband to convey artificial sensations of touch to the robotic hand users. Multiple channels of haptic feedback enabled subjects to successfully grasp and transport two objects simultaneously with the dexterous artificial hand without breaking or dropping them, even when their vision of both objects was obstructed. Simultaneous transport of the objects provided a significant time savings to perform the deliveries in comparison to a one-at-a-time approach. This paper demonstrated that subjects were able to integrate multiple channels of haptic feedback into their motor control strategies to perform a complex simultaneous object grasp control task with an artificial limb, which could serve as a paradigm shift in the way prosthetic hands are operated.

Greater and More Natural Use of the Upper Limbs During Everyday Life by Former Amputees Versus Prosthesis Users

Hand loss profoundly impacts daily functioning. Reversal of amputation through hand replantation or transplantation offers an alternative to prosthetics for some. Whether recipients exhibit more extensive and natural limb use during everyday life than prosthesis users is, however, unknown.We asked unilateral, below-elbow amputees (N = 22), hand graft recipients (transplants N = 4; replants N = 2), and healthy matched controls (N = 20) to wear wireless accelerometers distally on their forearms/prostheses and proximally on their upper arms. These units captured limb activity over 3 days within participants' natural environments.Graft recipients exhibited heavier reliance on their affected hands compared to amputees' reliance on their prostheses, P < .001. Likewise, reliance on the injured side upper arm was also greater for hand graft recipients than amputees, regardless of whether they were wearing their prostheses, P < .05 in both cases. Hand graft recipients, like healthy controls, also relied more on forearm vs upper arm movements when controlling their limbs, P < .001.Compared with conventional prosthesis users, graft recipients exhibited more extensive and natural functioning of the upper limbs during everyday activities. This information is an important addition to other considerations when evaluating risk-benefit of these treatment alternatives.

The Octopus Procedure Combined with Targeted Muscle Reinnervation for Elective Transhumeral Amputation

Optimizing prosthetic function and tolerance are key principles of performing an elective upper extremity amputation. It is common for upper extremity amputees to experience issues related to nonoptimal prosthetic control and pain. Targeted muscle reinnervation and regenerative peripheral nerve interfaces in elective transhumeral amputations have been introduced as techniques to address the paucity of signals that may exist for myoelectric control postamputation. These techniques require the denervation of muscle and rely on delayed muscle reinnervation to provide eventual signal amplification for prosthetic function. In addition, the fascicles cannot be separated enough to provide signals to each individual muscle. Use of native innervated forearm musculature can provide more immediate and specific signals for prosthetic use. These native muscles are often not available for use due to trauma, denervation, or dysvascularization. In elective amputations, they can be used as spare parts to provide more signals for the sensors on a myoelectric prosthetic. The concept has been used in partial hand amputations and allowed for individual digital control at the terminal prosthetic device. In this study, we describe a novel technique used for an elective transhumeral amputation utilizing native innervated, vascularized musculature to provide intuitive control of a myoelectric prosthetic.

Virtual Reality for Evaluating Prosthetic Hand Control Strategies: A Preliminary Report

Improving prosthetic hand functionality is critical in reducing abandonment rates and improving the amputee's quality of life. Techniques such as joint force estimation and gesture recognition using myoelectric signals could enable more realistic control of the prosthetic hand. To accelerate the translation of these advanced control strategies from lab to clinic, We created a virtual prosthetic control environment that enables rich user interactions and dexterity evaluation. The virtual environment is made of two parts, namely the Unity scene for rendering and user interaction, and a Python back-end to support accurate physics simulation and communication with control algorithms. By utilizing the built-in tracking capabilities of a virtual reality headset, the user can visualize and manipulate a virtual hand without additional motion tracking setups. In the virtual environment, we demonstrate actuation of the prosthetic hand through decoded EMG signal streaming, hand tracking, and the use of a VR controller. By providing a flexible platform to investigate different control modalities, we believe that our virtual environment will allow for faster experimentation and further progress in clinical translation.

Effective assessments to identify overuse injuries in unaffected limbs of persons with unilateral upper limb amputations

STUDY DESIGN

Cross-sectional study.

INTRODUCTION

Overuse injuries (OI) present major health problems and oftentimes, permanent disability. Persons with unilateral upper limb diagnoses, such as amputation, are at-risk for developing OI in their unaffected limbs. Measures to identify high-risk populations are needed.

PURPOSE OF THE STUDY

Scores on 6 OI-assessments were compared for persons with unilateral upper limb amputations (UULA) and healthy participants. Cutoff values were proposed.

METHODS

Sixty-two persons with UULA and 62 healthy controls completed this study. Scores for hand volume (HV), visual analogue scale (VAS), multi-site Semmes Weinstein Monofilament for median and ulnar nerves (SWM-M/SWM-U), torque range of motion for wrist/finger extension and flexion (TROM-E/TROM-F), intrinsic tightness (IT), and differential flexor tendon gliding (DFTG) were collected before and after 15 minutes of repetitive and resistive exercise. When analyzing collected data, descriptive statistics, and ANOVA were used to identify differences between groups. Receiver operating characteristic curves (ROC), area under the curve (AUC), sensitivity, and specificity were calculated to determine acceptable cutoff scores. Cutoff values with significant AUC ≥ 0.60 and sensitivity ≥ 0.80 were accepted.

RESULTS

Statistically significant differences were found between HV by gender in both pre-exercise and post-exercise conditions. Gain scores for whole sample HV, female HV, and TROM-E were statistically different although differences were small and not meaningful. Significant AUC and acceptable pre-exercise cutoff values included 375 ml. for female HV (sensitivity 89%, specificity 87%), 505 ml. for male HV (sensitivity 81%, specificity 70%), 82 degrees for TROM-E (sensitivity 92%, specificity 71%), and 73 degrees of TROM-F (sensitivity 90%, specificity 89%).

CONCLUSIONS

Potential at-risk OI-related populations, especially unaffected limbs of UULA persons, are best identified by pre-exercise cutoff values using HV by gender, TROM, and single-site SWM 2.83.

Upper limb prosthesis users: A longitudinal cohort study

BACKGROUND

No previous studies have followed prosthesis users with upper limb loss or limb deficiency using their own prostheses to assess change over time.

OBJECTIVES

(1) To describe prostheses and terminal device types used at baseline and 1-year follow-up; (2) to examine changes in functional outcomes and device satisfaction over time; and (3) to examine whether changes in outcomes varied across level of amputation and type of prosthesis used.

STUDY DESIGN

Multisite, observational time series design with in-person functional performance and self-report data collected at baseline and 1-year follow-up.

METHODS

Baseline and follow-up outcome scores were compared using Wilcoxon signed-rank tests. Analyses were stratified by amputation level, time since amputation, prosthesis type, and change in device type. Published minimal detectable change (MDC) values were used to determine whether detectable change in outcome measures occurred.

RESULTS

The longitudinal cohort consisted of 64 participants (mean age 64 years, 56% body-powered users). The only significant differences in outcome measures between baseline and follow-up (after adjustment for false discovery) were hours/day of prosthesis use, which increased from 6.0 (4.4) to 7.3 (5.3) hours (P = 0.0022). Differences in prosthesis use intensity remained significant in analyses stratified by amputation level, time since amputation, prosthesis type, and change in device type. Between 14 and 20% of the sample had change in one or more outcome measures that was greater than the known MDC.

CONCLUSIONS

Most participants had stable outcomes over a year's time, whereas 14-20% experienced either improvement or decline in one or more tests indicating the importance of annual follow-up visits.

Understanding the Relationship Between Patient-Reported Function and Actual Function in the Upper Limb Prosthesis User Population: A Preliminary Study

Objective

To understand how perceived function relates to actual function at a specific stage in the rehabilitation process for the population using upper limb prostheses.

Design

Quantitative clinical descriptive study.

Setting

Clinical offices.

Participants

A sample of 61 participants (N=61; mean age, 43.0±12.8y; 51 male/10 female) with upper limb amputation who use a prosthetic device and were in the definitive stage of a prosthesis fitting process.

Interventions

Not applicable.

Main Outcome Measures

A patient-reported outcome measure, the Disabilities of the Arm, Shoulder, and Hand questionnaire (DASH), and 2 performance-based outcome measures, Box and Blocks Test (BBT) and Capacity Assessment of Prosthesis Performance for the Upper Limb (CAPPFUL), were used as variables in multiple linear regression models.

Results

The multiple linear regression models, which controlled for prosthesis type and amputation level, did not show evidence that changes in the independent variable (DASH) are significantly associated with changes in the dependent variables (log(BBT) (B=−0.007; 95% confidence interval [CI], −0.015 to 0.001; P=.0937) and CAPPFUL (B=−0.083, 95% CI, −0.374 to 0.208; P=.5623)). In both models, individuals with elbow, transhumeral (above elbow), and shoulder disarticulation showed a significant negative association with the dependent variable (CAPPFUL or logBBT). In the CAPPFUL model, there was a significant negative association with individuals using a hybrid prosthesis (B=−20.252; 95% CI, −36.562 to −3.942; P=.0170). In the logBBT model, there was a significant positive association with individuals using body-powered prostheses (B=0.430; 95% CI, 0.089-0.771; P=.0157).

Conclusions

Although additional data and analyses are needed to more completely assess the association between self-reported measures and performance-based measures of functional abilities, these preliminary results indicate that patient-reported outcomes alone may not provide a complete assessment of an upper limb prosthesis users’ functional ability and should be accompanied by population-specific performance-based measures.

How Common Are Chronic Residual Limb Pain, Phantom Pain, and Back Pain More Than 20 Years After Lower Limb Amputation for Malignant Tumors?

BACKGROUND

After major lower limb amputation, persistent pain is common, with up to 85% of patients reporting recurring phantom or residual-limb pain. Although pain management is an important factor of quality of life in patients with lower limb amputations, there are few long-term data regarding the frequency of persistent pain and how it impacts prosthesis use.

QUESTIONS/PURPOSES

(1) How prevalent are different types of pain at long-term follow-up after amputation for malignant tumors? (2) What association do different pain types have with daily prosthesis use?

METHODS

Between 1961 and 1995, 124 major amputations for malignant tumors were performed at one center in Austria in patients (1) who spoke German and (2) whose surgical date resulted in the possibility of a minimum follow-up time of 20 years at the time of this survey; those patients were considered potentially eligible for this retrospective study. The indications for major amputation were to achieve local tumor control in limbs that the surgeon deemed unsalvageable without amputation. Of those 124 patients, 71% (88) had died, 9% (11) could not be reached, and 3% (4) declined to participate. Thus, 58% (21 of 36) of those living at the time of this study and who underwent lower limb amputation between 1961 and 1993 with a median (range) follow-up duration of 41 years (23 to 55) completed a standardized questionnaire, including an assessment of pain and daily prosthesis use during the year before the survey. Phantom pain, residual limb pain, and back pain were each further subclassified into pain frequency, intensity, and restrictions in activities of daily living (ADL) due to the specific pain form and rated on a 5- (pain frequency) and 10-point (pain intensity, restrictions in ADL) numerical rating scale. Before multivariate regression analysis, daily prosthesis use was correlated with pain parameters using Spearman correlation testing.

RESULTS

Seventeen of 21 patients reported phantom limb and back pain, and 15 patients reported residual limb pain in the past year. Median (range) phantom pain intensity was 7 (1 to 10) points, median residual limb pain intensity was 4 (1 to 9) points, and median back pain intensity was 5 (1 to 10) points. After controlling for relevant confounding variables such as age at amputation, age at survey, and stump length, we found that less intense residual limb pain (defined on a 10-point scale with 1 representing no pain at all and 10 representing extremely strong pain [95% CI 0.3 to 1.0]; r = 0.8; p = 0.003) was associated with greater daily prosthesis use. Higher amputation levels showed a decreased daily prosthesis use compared with patients with lower amputation levels (defined as transfemoral amputation versus knee disarticulation versus transtibial amputation [95% CI 0.3 to 5.1]; r = 0.5; p = 0.03).

CONCLUSION

Decades after surgery, many patients with lower limb amputations experience pain that restricts them in terms of ADLs and decreases their daily prosthesis use. This information supports the need for regular residual limb inspections and careful prosthesis fitting even at long-term follow-up, as effective prosthesis fitting is a modifiable cause of residual limb pain. Future studies evaluating long-term treatment effects of pain relief surgery and therapeutic alternatives to conservative pain treatments should be performed, as these approaches may help alleviate pain in patients with refractory postamputation pain.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Psychometric evaluation of the Southampton hand assessment procedure (SHAP) in a sample of upper limb prosthesis users

BACKGROUND

The 26-item Southampton Hand Assessment Protocol (SHAP) is a test of prosthetic hand function that generates an Index of Functionality (IOF), and prehensile pattern (PP) scores. Prior researchers identified potential issues in SHAP scoring, proposing alternative scoring methods (LIF and W-LIF).

STUDY DESIGN

Cross-sectional study.

PURPOSE

Evaluate the psychometric properties of the SHAP IOF, LIF, and W-LIF and PP scores and develop the Prosthesis Index of Functionality (P-IOF).

METHODS

We examined item completion, floor andceiling effects, concurrent, discriminant, construct and structural validity. The P-IOF used increased boundary limits and information from item completion and completion time. Calibration used a nonlinear mixed model. Scores were estimated using maximum a posteriori Bayesian estimation. Mixed integer linear programing (MILP) informed development of a shorter measure. Validity analyses were repeated using the P-IOF.

RESULTS

126 persons, mean age 57 (sd 15.8), 69% with transradial amputation were included. Floors effects were observed in 18.3%-19.1% for the IOF, LIF, and W-LIF. Ten items were not completed by >15% of participants. Boundary limits were problematic for all but 1 item. Correlations with dexterity measures were strong (r =  0.54-0.73). Scores differed by amputation level (p > .0001). Factor analysis did not support use of PP scores. The P-IOF used expanded boundary limits to decrease floor effects. MILP identified 10 items that could be dropped. The 26-item P-IOF and 16-item P-IOF had reduced floor effects (<7.5%), strong evidence of concurrent and discriminant validity, and construct validity. P-IOF reduced administrative burden by 9.5 (sd 5.6) minutes.

DISCUSSION

Floor effects limit a measure's ability to distinguish between persons with low function.

CONCLUSION

Analyses supported the validity of the SHAP IOF, LIF, and W-LIF, but identified large floor effects, as well as issues with structural validity of the PP scores. The 16-item P-IOF minimizes floor effects and reduces administrative burden.

Fascicle-Specific Targeting of Longitudinal Intrafascicular Electrodes for Motor and Sensory Restoration in Upper-Limb Amputees

Multichannel longitudinal intrafascicular electrode (LIFE) interfaces provide optimized balance of invasiveness and stability for chronic sensory stimulation and motor recording/decoding of peripheral nerve signals. Using a fascicle-specific targeting (FAST)-LIFE approach, where electrodes are individually placed within discrete sensory- and motor-related fascicular subdivisions of the residual ulnar and/or median nerves in an amputated upper limb, FAST-LIFE interfacing can provide discernment of motor intent for individual digit control of a robotic hand, and restoration of touch- and movement-related sensory feedback. The authors describe their findings from clinical studies performed with 6 human amputee trials using FAST-LIFE interfacing of the residual upper limb.

Frequency, severity, and implications of shoulder pain in people with major upper limb amputation who use prostheses: Results of a National Study

BACKGROUND

People with upper limb amputation are potentially at increased risk of shoulder pain because they often perform compensatory movements to operate their prostheses and rely more heavily on their nonamputated limb for everyday activities.

OBJECTIVE

To describe the frequency, severity, associated factors, and implications of shoulder pain in people with unilateral major upper limb amputation who use prostheses.

DESIGN

Cross-sectional, observational design.

SETTING

National recruitment of people living in the community.

PARTICIPANTS

U.S. veterans and civilians (N = 107) with unilateral major upper limb amputation.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Shoulder pain (any, ipsilateral and contralateral to amputation), activity performance (Activities Measure for Upper Limb Amputation), health-related quality of life (Veterans RAND 12-Item Health Survey mental component summary [MCS] and physical component summary [PCS]), and disability (Quick Version of the Disabilities of the Arm, Shoulder and Hand Score [QuickDASH]).

RESULTS

All participants completed a comprehensive in-person assessment. Participants were 97% male with a mean age of 57.1 years and a mean time since amputation of 23.4 years. The prevalence of any shoulder pain was 30% (15% ipsilateral, 25% contralateral, 10% bilateral). Shoulder pain intensity (0 to 10 scale) was moderate for both ipsilateral (mean 4.9, SD 2.0) and contralateral (mean 4.2, SD 2.0) pain. No significant difference in shoulder pain frequency was observed by amputation level. The prevalence of any shoulder pain was greater in those using a body-powered prosthesis (38% compared to 18% in externally powered users). Each additional year since amputation was associated with an increased likelihood of having contralateral shoulder pain (odds ratio: 1.05, confidence interval: 1.01, 1.10). In linear regression models, those with contralateral shoulder pain had worse PCS (β = -7.07, p = .008) and worse QuickDASH (β = 18.25, p < .001) scores.

CONCLUSIONS

In our sample of predominantly male veterans with major upper limb amputation, shoulder pain was a common condition associated with functional and quality of life implications. Among prosthesis users, the shoulder contralateral to the amputation was at greatest risk, with risk increasing with every year since amputation.

Hierarchical Tactile Sensation Integration from Prosthetic Fingertips Enables Multi-Texture Surface Recognition

Multifunctional flexible tactile sensors could be useful to improve the control of prosthetic hands. To that end, highly stretchable liquid metal tactile sensors (LMS) were designed, manufactured via photolithography, and incorporated into the fingertips of a prosthetic hand. Three novel contributions were made with the LMS. First, individual fingertips were used to distinguish between different speeds of sliding contact with different surfaces. Second, differences in surface textures were reliably detected during sliding contact. Third, the capacity for hierarchical tactile sensor integration was demonstrated by using four LMS signals simultaneously to distinguish between ten complex multi-textured surfaces. Four different machine learning algorithms were compared for their successful classification capabilities: K-nearest neighbor (KNN), support vector machine (SVM), random forest (RF), and neural network (NN). The time-frequency features of the LMSs were extracted to train and test the machine learning algorithms. The NN generally performed the best at the speed and texture detection with a single finger and had a 99.2 ± 0.8% accuracy to distinguish between ten different multi-textured surfaces using four LMSs from four fingers simultaneously. The capability for hierarchical multi-finger tactile sensation integration could be useful to provide a higher level of intelligence for artificial hands.

Pattern of upper limb amputation associated with lower limb amputation: the UK military experience from Iraq and Afghanistan

INTRODUCTION

The conflicts in Iraq and Afghanistan resulted in large numbers of personnel sustaining extremity injuries. In the context of polytrauma, partial hand amputation is often unrecorded. The aim of this work was to quantify the burden of upper limb (UL) amputation at any level occurring concurrently with a major (ankle and proximal) lower limb (LL) amputation. Knowledge of this cohort could aid in prosthetic modification to further improve quality of life outcomes in a population with dexterity loss.

METHOD

A trauma database search was undertaken for all UK military LL amputees from the conflicts in Iraq and Afghanistan. A manual search method was employed to identify from the major LL amputees those who had a concurrent UL amputation at any level (including isolated finger amputation). Demographics, level of amputation, and injury profile data were recorded.

RESULTS

Sixty-eight individuals were identified; the most prevalent population was bilateral LL with a unilateral UL amputation (60%). Most UL amputations were partial hand (75%). The was no statistically significant difference between left or right side (p=0.13). On the left side, correlation was found between amputation of the thumb and third digit (rho=0.34; p=0.005) not seen on the right.

CONCLUSION

We have determined the rate of UL amputation at any level, in combination with LL amputation as a result of blast injury. Knowledge of these combinations enables further research to support anecdotal evidence that there is a need for tailored prosthetics in the context of potential dexterity loss making donning and doffing problematic.

Veterans' satisfaction and perspectives on helpfulness of the Veterans Crisis Line

OBJECTIVE

Crisis hotlines are an important part of a public health approach to suicide prevention. The Veterans Crisis Line (VCL) provides hotline services to Veterans. There is a paucity of research concerning the effectiveness of the VCL. The current work describes efforts to establish groundwork for VCL effectiveness research.

METHODS

155 VCL users who were referred to a Veterans Affairs Medical Center Suicide Prevention Team completed interviews including open-ended and closed-ended questions. Outcomes are reported for suicidal participants, non-suicidal participants, and those who had emergency intervention. Thematic analysis was used for open-ended questions.

RESULTS

Eighty-seven percent of interviewees expressed satisfaction with the VCL, 81.9% reported that the VCL was helpful, and 72.9% said that the VCL helped keep them safe. Of those with suicidal thoughts, 82.6% said the contact helped stop them from killing themselves. Themes are described concerning user identified reasons for VCL contact, most and least helpful aspects of the contact, and suggestions for improvement.

DISCUSSION

This project demonstrates that this group of people who used the VCL overwhelmingly finds the service to be helpful and a barrier to suicide. Further, implications of user feedback for application to VCL operations and future research are discussed.

Amputation Care Quality and Satisfaction With Prosthetic Limb Services: A Longitudinal Study of Veterans With Upper Limb Amputation

Purpose

This study sought to measure and identify factors associated with satisfaction with care among veterans. The metrics were colelcted for those receiving prosthetic limb care at the US Department of Veterans Affairs (VA) and US Department of Defense (DoD) care settings and at community-based care providers.

Methods

A longitudinal cohort of veterans with major upper limb amputation receiving any VA care from 2010 to 2015 were interviewed by phone twice, 1 year apart. Care satisfaction was measured by the Orthotics and Prosthetics User's Survey (OPUS) client satisfaction survey (CSS), and prosthesis satisfaction was measured by the OPUS client satisfaction with device (CSD), and the Trinity Amputation and Prosthetic Experience Scale satisfaction scales. The Quality of Care index, developed for this study, assessed care quality. Bivariate analyses and multivariable linear regressions identified factors associated with CSS. Wilcoxon Mann-Whitney rank tests and Fisher exact tests compared CSS and Quality of Care items at follow-up for those with care within and outside of the VA and DoD.

Results

The study included 808 baseline participants and 585 follow-up participants. Device satisfaction and receipt of amputation care in the prior year were associated with greater satisfaction with care quality. Persons with bilateral amputation were significantly less satisfied with wait times. Veterans who received amputation care in the VA or DoD had better, but not statistically different, mean (SD) CSS scores: 31.6 (22.6) vs 39.4 (16.9), when compared with those who received care outside the VA or DoD. Those with care inside the VA or DoD were also more likely to have a functional assessment in the prior year (33.7% vs 7.1%, P = .06), be contacted by providers (42.7% vs 18.8%, P = .07), and receive amputation care information (41.6% vs 0%, P =.002). No statistically significant differences in CSS, Quality of Care scores, or pain measures were observed between baseline and follow-up. In regression models, those with higher CSD scores and with prior year amputation care had higher satisfaction when compared to those who had not received care.

Conclusions

Satisfaction with prosthetic limb care is associated with device satisfaction and receipt of care within the prior year. Veterans receiving amputation care within the VA or DoD received better care quality scores than those receiving prosthetic care outside of the VA or DoD. Satisfaction with care and quality of care were stable over the 12 months of this study. Findings from this study can serve as benchmarks for future work on care satisfaction and quality of amputation rehabilitative care.

Longitudinal study of prosthesis use in veterans with upper limb amputation

BACKGROUND

Little is known about the patterns of prosthesis use and satisfaction of those who cease use or begin to use upper limb prostheses.

OBJECTIVES

Among a longitudinal sample of Veterans with upper limb amputation, (1) describe changes in prosthesis use over 1 year, (2) examine rates of receipt of new prostheses, and (3) compare prosthesis satisfaction in respondents who received a new prosthesis to those who did not.

STUDY DESIGN

Longitudinal survey.

METHODS

808 Veterans who had participated in a baseline interview 1 year earlier were invited to participate in structured telephone interviews.

RESULTS

A total of 562 persons with unilateral and 23 with bilateral amputation participated in the interviews (Response rate = 72.4% and 85.2%, respectively). Prosthesis use, frequency and intensity of use, and types of prostheses used were stable over 1 year. About 24% reported using a different primary terminal device type at follow-up than baseline. Prosthesis use was less frequent/intense at baseline among those who discontinued use compared with those who did not (P < 0.05), and less frequent/intense for those who started compared with those who continued using a prosthesis (P < 0.0001). Rates of prosthetic training were higher among those who received a different prosthesis type compared with those using the same type (P = 0.06). Satisfaction scores were higher (P < 0.01) for new prosthesis recipients, and lower at baseline for prosthesis abandoners compared with continued users (P = 0.03).

CONCLUSION

Prosthesis abandonment appears to be predicated on dissatisfaction with the device, as well as less frequent/intense prosthesis use. These findings can be used to identify those at risk for prosthesis abandonment and improve their prosthesis experience.

Managing Neuroma and Phantom Limb Pain in Ontario: The Status of Targeted Muscle Reinnervation

Supplemental Digital Content is available in the text.

Background:

Painful neuromas (PN) and phantom limb pain (PLP) are common following amputation and are unreliably treated, which impacts quality of life. Targeted muscle reinnervation (TMR) is a microsurgical technique that repairs the severed proximal nerve end to a redundant motor nerve in the amputated stump. Evidence supports TMR as effective in treating PN and PLP; however, its adoption has been slow. This study aimed to characterize: (1) the populations experiencing post-amputation PN/PLP; (2) current trends in managing PN/PLP; and (3) attitudes toward routine use of TMR to manage PN/PLP.

Methods:

A cross-sectional survey was distributed to all orthopedic surgeons, plastic surgeons, and physiatrists practicing in Ontario, via publicly available emails and specialty associations. Data were collected on demographics, experience with amputation, managing post-amputation pain, and attitudes toward routine use of TMR.

Results:

Sixty-six of 698 eligible participants submitted complete surveys (9.5% response rate). Respondents had a greater experience with surgical management of PN (71% PN versus 10% PLP). However, surgery was considered a 3rd-line option for PN and not an option for PLP in 57% and 59% of respondents, respectively. Thirty participants (45%) were unaware of TMR as an option, and only 8 respondents have currently incorporated TMR into their practice. Many (76%) would be willing to incorporate TMR into their practice as either an immediate or delayed surgical technique.

Conclusions:

Despite its promise in managing post-amputation pain, awareness of TMR as a surgical option is generally poor. Several barriers to the widespread adoption of this technique are defined.

Feedback-aided data acquisition improves myoelectric control of a prosthetic hand

OBJECTIVE

Pattern-recognition-based myocontrol can be unreliable, which may limit its use in the clinical practice and everyday activities. One cause for this is the poor generalization of the underlying machine learning models to untrained conditions. Acquiring the training data and building the model more interactively can reduce this problem. For example, the user could be encouraged to target the model's instabilities during the data acquisition supported by automatic feedback guidance. Interactivity is an emerging trend in myocontrol of upper-limb electric prostheses: the user should be actively involved throughout the training and usage of the device.

APPROACH

In this study, 18 non-disabled participants tested two novel feedback-aided acquisition protocols against a standard one that did not provide any guidance. All the protocols acquired data dynamically in multiple arm positions to counteract the limb position effect. During feedback-aided acquisition, an acoustic signal urged the participant to hover with the arm in specific regions of her peri-personal space, de facto acquiring more data where needed. The three protocols were compared on everyday manipulation tasks performed with a prosthetic hand.

MAIN RESULTS

Our results showed that feedback-aided data acquisition outperformed the acquisition routine without guidance, both objectively and subjectively.

SIGNIFICANCE

This indicates that the interaction with the user during the data acquisition is fundamental to improve myocontrol.

Risk Factors for Neuropathic Pain Following Major Upper Extremity Amputation

BACKGROUND

 Active treatment (targeted muscle reinnervation [TMR] or regenerative peripheral nerve interfaces [RPNIs]) of the amputated nerve ends has gained momentum to mitigate neuropathic pain following amputation. Therefore, the aim of this study is to determine the predictors for the development of neuropathic pain after major upper extremity amputation.

METHODS

 Retrospectively, 142 adult patients who underwent 148 amputations of the upper extremity between 2000 and 2019 were identified through medical chart review. All upper extremity amputations proximal to the metacarpophalangeal joints were included. Patients with a follow-up of less than 6 months and those who underwent TMR or RPNI at the time of amputation were excluded. Neuropathic pain was defined as phantom limb pain or a symptomatic neuroma reported in the medical charts at 6 months postoperatively. Most common indications for amputation were oncology (n = 53, 37%) and trauma (n = 45, 32%), with transhumeral amputations (n = 44, 30%) and shoulder amputations (n = 37, 25%) being the most prevalent.

RESULTS

 Neuropathic pain occurred in 42% of patients, of which 48 (32%) had phantom limb pain, 8 (5.4%) had a symptomatic neuroma, and 6 (4.1%) had a combination of both. In multivariable analysis, traumatic amputations (odds ratio [OR]: 4.1, p = 0.015), transhumeral amputations (OR: 3.9, p = 0.024), and forequarter amputations (OR: 8.4, p = 0.003) were independently associated with the development of neuropathic pain.

CONCLUSION

 In patients with an upper extremity amputation proximal to the elbow or for trauma, there is an increased risk of developing neuropathic pain. In these patients, primary TMR/RPNI should be considered and this warrants a multidisciplinary approach involving general trauma surgeons, orthopaedic surgeons, plastic surgeons, and vascular surgeons.

Prevalence and incidence of phantom limb pain, phantom limb sensations and telescoping in amputees: A systematic rapid review

BACKGROUND AND OBJECTIVE

This systematic, rapid review aimed to critically appraise and synthesize the recent literature (2014-2019) evaluating the incidence and prevalence of post-amputation phantom limb pain (PLP) and sensation (PLS).

DATABASES AND DATA TREATMENT

Five databases (Medline, Embase, Emcare, PsychInfo, Web of Science) and Google Scholar were searched, with two independent reviewers completing eligibility screening, risk of bias assessment and data extraction.

RESULTS

The search identified 1,350 studies with 12 cross-sectional and 3 prospective studies included. Studies evaluated traumatic (n = 5), atraumatic (n = 4), and combined traumatic/atraumatic (n = 6) amputee populations, ranging from 1 month to 33 years post-amputation. Study heterogeneity prevented data pooling. The majority of studies had a high risk of bias, primarily due to limited generalizability. Three studies evaluated PLP incidence, ranging from 2.2% (atraumatic; 1 month) to 41% (combined; 3 months) and 82% (combined; 12 months). Only one study evaluated PLS/telescoping incidence. Across contrasting populations, PLP point prevalence was between 6.7%-88.1%, 1 to 3-month period prevalence was between 49%-93.5%, and lifetime prevalence was high at 76%-87%. Point prevalence of PLS was 32.4%-90%, period prevalence was 65% (1 month) and 56.9% (3 months), and lifetime prevalence was 87%. Telescoping was less prevalent, highest among traumatic amputees (24.6%) within a 1-month prevalence period. Variations in population type (e.g. amputation characteristics) and incidence and prevalence measures likely influence the large variability seen here.

CONCLUSIONS

This review found that lifetime prevalence was the highest, with most individuals experiencing some type of phantom phenomena at some point post-amputation.

SIGNIFICANCE

This systematic rapid review provides a reference for clinicians to make informed prognosis estimates of phantom phenomena for patients undergoing amputation. Results show that most amputees will experience phantom limb pain (PLP) and phantom limb sensations (PLS): high PLP incidence 1-year post-amputation (82%); high lifetime prevalence for PLP (76%-87%) and PLS (87%). Approximately 25% of amputees will experience telescoping. Consideration of individual patient characteristics (cause, amputation site, pre-amputation pain) is pertinent given their likely contribution to incidence/prevalence of phantom phenomena.

Function and Quality of Life of Unilateral Major Upper Limb Amputees: Effect of Prosthesis Use and Type

OBJECTIVE

To compare patient-reported outcomes of disability, activity difficulty, and health-related quality of life (HRQOL) by prosthetic device use and configuration and to identify factors associated with these outcomes.

DESIGN

Telephone survey.

SETTING

General community.

PARTICIPANTS

Population-based sample of veterans (N=755) with unilateral upper limb amputation recruited from a national sample of veterans with upper limb amputation who received care at the Veterans Affairs clinic from 2010-2015.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Upper limb-related disability was measured using Disabilities of the Arm, Shoulder, and Hand score (QuickDASH). HRQOL was measured using the Veterans RAND 12-item Health Survey Mental and Physical Component scores. Activity difficulty was assessed for 1-handed and 2-handed tasks and by questions about the need for help with activities of daily living (ADLs).

RESULTS

Patients who did not use a prosthesis had more difficulty performing 1-handed tasks using the residual limb as compared with those who used body-powered prostheses. Cosmetic device users had more task difficulty than body-powered or myoelectric users. Linear regression models did not show an association between type of prosthesis used and HRQOL scores, but did show that those who did not use a prosthesis (non-users) had worse QuickDASH scores (β=9.4; P=.0004) compared to body-powered users. In logistic regression modeling, the odds of needing help with ADLs were 1.84 times higher (95% confidence interval, 1.16-2.92) for non-users compared with body-powered users.

CONCLUSIONS

Amputees who did not use a prosthesis or used a cosmetic prosthesis reported more difficulty in activities and greater disability as compared with those who use body-powered and myoelectric devices. Non-users were more likely to need help with ADLs as compared with those who used a body-powered prosthesis. Our findings highlight the clinical importance of encouraging prosthesis use. Further research is needed to compare physical performance by prosthesis configuration.

A National Survey of Prosthesis Use in Veterans with Major Upper Limb Amputation: Comparisons by Gender

BACKGROUND

A better understanding of women veterans with upper limb amputation is needed.

OBJECTIVE

To compare prosthetic use and outcomes of female and male veterans with upper limb amputation.

DESIGN

Cross-sectional survey: Amputation characteristics, prosthesis use, and quality of life outcomes were compared by gender. Separate logistic regression models examined association of gender with prosthesis use and receipt of training to use a prosthesis. Separate linear regression models examined the relationship between gender and health-related quality of life (HRQoL) outcomes.

PARTICIPANTS

Participants were veterans with major upper limb amputation who received care at the Department of Veterans Affairs (VA) in 2010-2015, identified from VA data sources. A total of 808 individuals (755 men, 21 women) were surveyed by telephone.

MAIN OUTCOME MEASURES

Disabilities of the Arm, Shoulder and Hand (QuickDASH), VR-12 Physical Component Summary (PCS) and VR-12 Mental Component Summary (MCS), Trinity Amputation and Prosthetic Experience Scale satisfaction scale, Orthotics and Prosthetic User's Survey client satisfaction with devices scale.

SETTING

Telephone survey of community dwelling participants.

INTERVENTIONS

Not applicable.

RESULTS

Survey response rate was 47.3% for men and 62.8% for women. Women were less likely to have ever used a prosthesis (adjusted odds ratio [aOR] = 0.26; confidence interval [CI] 0.08-0.88), have received training for an initial prosthesis (aOR: 0.24; CI 0.08-0.70), be current users (aOR = 0.34; CI 0.12-1.01), and have received training for a current prosthesis (aOR: 0.15; 0.03-0.87). A greater proportion of women used cosmetic and a smaller proportion used body-powered devices compared to men (P < .05). Device heaviness or fatigue was the most common reason for abandonment. There were no significant differences in outcome measures by gender.

CONCLUSIONS

Women were less likely than men to have ever used and currently use prostheses or to have received prosthetic training, more likely to use cosmetic devices, and less likely to use body-powered devices. Efforts to develop prostheses that are cosmetically acceptable, yet lightweight and functional, are needed.

Prosthesis satisfaction in a national sample of Veterans with upper limb amputation

BACKGROUND

Many persons with upper limb amputation reject prostheses, and many are not satisfied with their devices. Research is needed to understand modifiable factors related to device satisfaction. Myoelectric devices with multiple degrees of freedom are now available; however, no studies have examined whether they lead to greater device satisfaction. Prosthetic training contributes to more skillful prosthesis use and greater likelihood of long-term use; however, the relationship between training and device satisfaction is unclear.

OBJECTIVES

(1) To describe and compare satisfaction by prosthesis and terminal device type and (2) to identify factors associated with satisfaction.

STUDY DESIGN

Cross-sectional study.

METHODS

Participants were 449 persons with unilateral upper limb amputation who used a prosthesis. Participants described their prostheses, prosthetic training, device repairs, visits to a prosthetist, and rated device satisfaction using two standardized measures (Trinity Amputation and Prosthesis Experience Scales Satisfaction scale and Orthotics and Prosthetics Users' Survey - Client Satisfaction with Devices scale). Multivariate generalized linear regression models examined the relationship between prosthesis and terminal device type and satisfaction, controlling for covariates that were meaningful in bivariate analyses.

RESULTS

There were no differences in satisfaction by prosthesis type or terminal device degrees of freedom. Satisfaction was associated with receipt of training to use the initial prosthesis, amputation level, age, and race.

CONCLUSION

No differences in satisfaction by device or terminal device type were observed. Worse satisfaction was associated with more proximal amputation level, younger age, and black race. The association between receipt of initial prosthetic training and device satisfaction points to the critical role of occupational or physical therapy in the early stages of prosthetic care.

CLINICAL RELEVANCE

Prosthetic satisfaction did not vary by device or terminal device degrees of freedom. Proximal amputation level, younger age, and black race were associated with lower prosthetic satisfaction. Receipt of initial prosthetic training was associated with greater device satisfaction, pointing to the critical role and lasting impact of early training.