A scoring system to evaluate stability of percutaneous osseointegrated implants for transfemoral amputation with validation in the ITAP clinical trial

Percutaneous osseointegrated implants for individuals with lower limb amputation can increase mobility, reduce socket related pain, and improve quality of life. It would be useful to have an evaluation method to assess the interface between bone and implant. We assessed outpatient radiographs from the Intraosseous Transcutaneous Amputation Prosthesis clinical trial using an interface scoring system which summed and weighted equally measures of implant collar cortical ongrowth and radiolucency along the implant stem/bone interface. Radiographs from 12 participants with unilateral transfemoral amputations (10 males, 2 females, mean age = 43.2, SD = 7.4 years) in the clinical trial from cohort I (implanted in 2008/09) or cohort II (implanted in 2013/14) were collated (mean image span = 7.2, SD = 2.4 years), scale normalised, zoned, and measured in a repeatable way. Interface scores were calculated and then compared to clinical outcomes. Explanted participants received the lowest interface scores. A higher ratio of stem to residuum and shorter residuum's produced better interface scores and there was an association (weak correlation) between participants with thin cortices and the lowest interface scores. A tapered, cemented, non curved stem may provide advantageous fixation while stem alignment did not appear critical. In summary, the interface score successfully demonstrated a non-invasive evaluation of percutaneous osseointegrated implants interfaces when applied to the Intraosseous Transcutaneous Amputation Prosthesis clinical trial. The clinical significance of this work is to identify events leading to aseptic or septic implant removal and contribute to clinical guidelines for monitoring rehabilitation, design and surgical fixation choices.

Lifetime cost-effectiveness analysis osseointegrated transfemoral versus socket prosthesis using Markov modelling

Aims

Prior cost-effectiveness analyses on osseointegrated prosthesis for transfemoral unilateral amputees have analyzed outcomes in non-USA countries using generic quality of life instruments, which may not be appropriate when evaluating disease-specific quality of life. These prior analyses have also focused only on patients who had failed a socket-based prosthesis. The aim of the current study is to use a disease-specific quality of life instrument, which can more accurately reflect a patient's quality of life with this condition in order to evaluate cost-effectiveness, examining both treatment-naïve and socket refractory patients.

Methods

Lifetime Markov models were developed evaluating active healthy middle-aged male amputees. Costs of the prostheses, associated complications, use/non-use, and annual costs of arthroplasty parts and service for both a socket and osseointegrated (OPRA) prosthesis were included. Effectiveness was evaluated using the questionnaire for persons with a transfemoral amputation (Q-TFA) until death. All costs and Q-TFA were discounted at 3% annually. Sensitivity analyses on those cost variables which affected a change in treatment (OPRA to socket, or socket to OPRA) were evaluated to determine threshold values. Incremental cost-effectiveness ratios (ICERs) were calculated.

Results

For treatment-naïve patients, the lifetime ICER for OPRA was $279/quality-adjusted life-year (QALY). For treatment-refractory patients the ICER was $273/QALY. In sensitivity analysis, the variable thresholds that would affect a change in the course of treatment based on cost (from socket to OPRA), included the following for the treatment-naïve group: yearly replacement components for socket > $8,511; cost yearly replacement parts OPRA < $1,758; and for treatment-refractory group: yearly replacement component for socket of > $12,467.

Conclusion

The use of the OPRA prosthesis in physically active transfemoral amputees should be considered as a cost-effective alternative in both treatment-naïve and treatment-refractory socket prosthesis patients. Disease-specific quality of life assessments such as Q-TFA are more sensitive when evaluating cost-effectiveness.

Continuous A-Mode Ultrasound-Based Prediction of Transfemoral Amputee Prosthesis Kinematics Across Different Ambulation Tasks

OBJECTIVE

Volitional control systems for powered prostheses require the detection of user intent to operate in real life scenarios. Ambulation mode classification has been proposed to address this issue. However, these approaches introduce discrete labels to the otherwise continuous task that is ambulation. An alternative approach is to provide users with direct, voluntary control of the powered prosthesis motion. Surface electromyography (EMG) sensors have been proposed for this task, but poor signal-to-noise ratios and crosstalk from neighboring muscles limit performance. B-mode ultrasound can address some of these issues at the cost of reduced clinical viability due to the substantial increase in size, weight, and cost. Thus, there is an unmet need for a lightweight, portable neural system that can effectively detect the movement intention of individuals with lower-limb amputation.

METHODS

In this study, we show that a small and lightweight A-mode ultrasound system can continuously predict prosthesis joint kinematics in seven individuals with transfemoral amputation across different ambulation tasks. Features from the A-mode ultrasound signals were mapped to the user's prosthesis kinematics via an artificial neural network.

RESULTS

Predictions on testing ambulation circuit trials resulted in a mean normalized RMSE across different ambulation modes of 8.7 ± 3.1%, 4.6 ± 2.5%, 7.2 ± 1.8%, and 4.6 ± 2.4% for knee position, knee velocity, ankle position, and ankle velocity, respectively.

CONCLUSION AND SIGNIFICANCE

This study lays the foundation for future applications of A-mode ultrasound for volitional control of powered prostheses during a variety of daily ambulation tasks.

Design, Analysis, and Development of Low-Cost State-of-the-Art Magnetorheological-Based Microprocessor Prosthetic Knee

For amputees, amputation is a devastating experience. Transfemoral amputees require an artificial lower limb prosthesis as a replacement for regaining their gait functions after amputation. Microprocessor-based transfemoral prosthesis has gained significant importance in the last two decades for the rehabilitation of lower limb amputees by assisting them in performing activities of daily living. Commercially available microprocessor-based knee joints have the needed features but are costly, making them beyond the reach of most amputees. The excessive cost of these devices can be attributed to custom sensing and actuating mechanisms, which require significant development cost, making them beyond the reach of most amputees. This research contributes to developing a cost-effective microprocessor-based transfemoral prosthesis by integrating off-the-shelf sensing and actuating mechanisms. Accordingly, a three-level control architecture consisting of top, middle, and low-level controllers was developed for the proposed prosthesis. The top-level controller is responsible for identifying the amputee intent and mode of activity. The mid-level controller determines distinct phases in the activity mode, and the low-level controller was designed to modulate the damping across distinct phases. The developed prosthesis was evaluated on unilateral transfemoral amputees. Since off-the-shelf sensors and actuators are used in i-Inspire, various trials were conducted to evaluate the repeatability of the sensory data. Accordingly, the mean coefficients of correlation for knee angle, force, and inclination were computed at slow and medium walking speeds. The obtained values were, respectively, 0.982 and 0.946 for knee angle, 0.942 and 0.928 for knee force, and 0.825 and 0.758 for knee inclination. These results confirmed that the data are highly correlated with minimum covariance. Accordingly, the sensors provide reliable and repeatable data to the controller for mode detection and intent recognition. Furthermore, the knee angles at self-selected walking speeds were recorded, and it was observed that the i-Inspire Knee maintains a maximum flexion angle between 50° and 60°, which is in accordance with state-of-the-art microprocessor-based transfemoral prosthesis.

Positive Outcomes of Physiotherapy in a Post-operative Case of Squamous Cell Carcinoma of Tongue and Buccal Mucosa Along With Transfemoral Amputation

Oral cancer is a type of malignant neoplasia that develops in the oral cavity or lips and is commonly referred to as squamous cell carcinoma (SCC) because of its histopathology. In this report, we present to you a case of a 35-year-old male patient operated on for moderately differentiated SCC of the lateral border of the tongue and right buccal mucosa with a two-year-old case of trans-femoral amputation. Postoperatively, the patient faced issues with breathing, mouth opening and closing limitations, and painful movements of the neck and right shoulder. An intensive physiotherapy care regimen was designed and consistently implemented for two weeks to tackle the surgical results that were compromising the patient's quality of life. At the two-week evaluation, enhancements in tongue movement, mouth opening, shoulder and cervical joint movement, thoracic mobility, lower limb strength, and gait were seen, confirming the efficacy of the intended therapy. The patient was assessed before and after the rehabilitation using range of motion, manual muscle testing, the Mallampati scale, the numerical pain rating scale, the amputee mobility predictor assessment tool, and the Royapettah scoring system.

Approach for Non-Intrusive Detection of the Fit of Orthopaedic Devices Based on Vibrational Data

The soft tissues of residual limb amputees are subject to large volume fluctuations over the course of a day. Volume fluctuations in residual limbs can lead to local pressure marks, causing discomfort, pain and rejection of prostheses. Existing methods for measuring interface stress encounter several limitations. A major problem is that the measurement instrumentation is applied in the sensitive interface between the prosthesis and residual limb. This paper presents the principle investigation of a non-intrusive technique to evaluate the fit of orthopaedic prosthesis sockets in transfemoral amputees based on experimentally obtained vibrational data. The proposed approach is based on changes in the dynamical behaviour detectable at the outer surface of prostheses; thus, the described interface is not affected. Based on the experimental investigations shown and the derived results, it can be concluded that structural dynamic measurements are a promising non-intrusive technique to evaluate the fit of orthopaedic prosthesis sockets in transfemoral amputee patients. The obtained resonance frequency changes of 2% are a good indicator of successful applicabilityas these changes can be detected without the need for complex measurement devices.

Design and evaluation of the pneumatic leg prosthesis ERiK to assist elderly amputees with sit-down and stand-up movements

Standing up using one leg is a challenging task for those with a transfemoral amputation, particularly for elderly users with a low activity level. Active prostheses are generally not accessible to this group and available passive prostheses do not support standing up. This article presents the design and evaluation of the "Energy Restoring Intelligent Knee" (ERiK), which stores energy during sit-down in a pneumatic cylinder and returns it during stand-up. We hypothesized that the system would reduce the time needed to perform transitions and also enable higher load sharing by the prosthetic leg. However, the results of an experimental study with seven participants with transfemoral amputation contradict these hypotheses: the participants could neither move faster nor make more use of the prosthetic leg to share their body weight during transitions. We observed that a major obstacle to the useful functionality of the leg was the absence of ankle dorsiflexion - the foot tended to slip during stand-up initiation, such that only low pre-pressures and therefore support levels could be set. The rather binary action of the pneumatics also complicated movement initiation. The lessons learned from this study may be helpful to those seeking to create better designs in the future.

Longitudinal Gait Analysis of a Transfemoral Amputee Patient: Single-Case Report from Socket-Type to Osseointegrated Prosthesis

The aim of the present case report was to provide a longitudinal functional assessment of a patient with transfemoral amputation from the preoperative status with socket-type prosthesis to one year after the osseointegration surgery. A 44 years-old male patient was scheduled for osseointegration surgery 17 years after transfemoral amputation. Gait analysis was performed through 15 wearable inertial sensors (MTw Awinda, Xsens) before surgery (patient wearing his standard socket-type prosthesis) and at 3-, 6-, and 12-month follow-ups after osseointegration. ANOVA in Statistical Parametric Mapping was used to assess the changes in amputee and sound limb hip and pelvis kinematics. The gait symmetry index progressively improved from the pre-op with socket-type (1.14) to the last follow-up (1.04). Step width after osseointegration surgery was half of the pre-op. Hip flexion-extension range significantly improved at follow-ups while frontal and transverse plane rotations decreased (p < 0.001). Pelvis anteversion, obliquity, and rotation also decreased over time (p < 0.001). Spatiotemporal and gait kinematics improved after osseointegration surgery. One year after surgery, symmetry indices were close to non-pathological gait and gait compensation was sensibly decreased. From a functional point of view, osseointegration surgery could be a valid solution in patients with transfemoral amputation facing issues with traditional socket-type prosthesis.

Does obesity predict morbidity and mortality amongst patients undergoing transfemoral amputations?

BACKGROUND

We investigated the role of obesity on morbidity and mortality in patients undergoing above knee amputation.

METHODS

Data of 4225 patients undergoing AKAs was extracted from NIS Database (2016-2019) for a retrospectively matched case-control study and were grouped into; Non-obese (N-Ob-BMI <29.9 kg/m²; n = 1413), class I/II obese (Ob-I/II-BMI: 30-39.9 kg/m²; n = 1413), and class III obese groups (Ob-IIIBMI > 40; n = 1399). Morbidity, mortality, length of stay, and hospital charges were analyzed.

RESULTS

Blood loss anemia (OR = 1.42; 95% CI = 1.19-1.64), superficial SSI (OR = 5.10; 95% CI = 1.4717.63) and acute kidney injury (AKI- OR = 1.42; 95% CI = 1.21-1.67) were higher in Ob-III patients. Mortality was 5.8%, 4.5%, and 6.4% in N-Ob, Ob-I/II and Ob-III patients (p < 0.001; Ob-I/II vs. Ob-III), respectively. Hospital LOS was 3 days higher in Ob-III (16.1 ± 18.0), comparatively resulting in $25,481 higher inpatient-hospital charge.

CONCLUSION

Patients in Ob-III group were noted to have increased morbidity, higher LOS, and inpatient-hospital cost.

A-Mode Ultrasound-Based Prediction of Transfemoral Amputee Prosthesis Walking Kinematics Via an Artificial Neural Network

Lower-limb powered prostheses can provide users with volitional control of ambulation. To accomplish this goal, they require a sensing modality that reliably interprets user intention to move. Surface electromyography (EMG) has been previously proposed to measure muscle excitation and provide volitional control to upper- and lower-limb powered prosthesis users. Unfortunately, EMG suffers from a low signal to noise ratio and crosstalk between neighboring muscles, often limiting the performance of EMG-based controllers. Ultrasound has been shown to have better resolution and specificity than surface EMG. However, this technology has yet to be integrated into lower-limb prostheses. Here we show that A-mode ultrasound sensing can reliably predict the prosthesis walking kinematics of individuals with a transfemoral amputation. Ultrasound features from the residual limb of 9 transfemoral amputee subjects were recorded with A-mode ultrasound during walking with their passive prosthesis. The ultrasound features were mapped to joint kinematics through a regression neural network. Testing of the trained model against untrained kinematics from an altered walking speed show accurate predictions of knee position, knee velocity, ankle position, and ankle velocity, with a normalized RMSE of 9.0 ± 3.1%, 7.3 ± 1.6%, 8.3 ± 2.3%, and 10.0 ± 2.5% respectively. This ultrasound-based prediction suggests that A-mode ultrasound is a viable sensing technology for recognizing user intent. This study is the first necessary step towards implementation of volitional prosthesis controller based on A-mode ultrasound for individuals with transfemoral amputation.

Transfemoral amputation and prosthesis provision in Tanzania: Patient and provider perspectives

Background

The burden of disability because of traumatic limb amputation, particularly transfemoral amputation (TFA) is disproportionately carried by low- and middle-income countries. The need for improved access to prosthesis services in these settings is well-documented, but perspectives on the burden imposed by TFA and the challenges associated with subsequent prosthesis provision vary among patients, caregivers and healthcare providers.

Objectives

To examine the burden of TFA and barriers to prosthesis provision as perceived by patient, caregiver and healthcare professional, at a single tertiary referral hospital in Tanzania.

Method

Data were collected from five patients with TFA and four caregivers recruited via convenience sampling, in addition to 11 purposively sampled healthcare providers. All participants participated in in-depth interviews regarding their perceptions of amputation, prostheses and underlying barriers to improving care for persons with TFA in Tanzania. A coding schema and thematic framework were established from interviews using inductive thematic analysis.

Results

All participants noted financial and psychosocial burdens of amputation, and perceived prostheses as an opportunity for return to normality and independence. Patients worried about prosthesis longevity. Healthcare providers noted significant obstacles to prosthesis provision, including infrastructural and environmental barriers, limited access to prosthetic services, mismatched patient expectations and inadequate coordination of care.

Conclusion

This qualitative analysis identifies factors influencing prosthesis-related care for patients with TFA in Tanzania which are lacking in the literature. Persons with TFA and their caregivers experience numerous hardships exacerbated by limited financial, social and institutional support.

Contribution

This qualitative analysis informs future directions for research into improving prosthesis-related care for patients with TFA in Tanzania.

Morbidity and Mortality in Non-Obese Compared to Different Classes of Obesity in Patients Undergoing Transtibial Amputations

This study assesses the effect of obesity classes on outcomes and inpatient-hospital-cost compared to non-obese individuals undergoing below-knee amputations (BKAs). Retrospective matched-case controlled study performed on data from NIS Database. We identified three groups: N-Ob (BMI < 29.9 kg/m2; n = 3104), Ob-I/II (BMI: 30 to 39.9 kg/m2; n = 3107), and Ob-III (BMI > 40; n = 3092); matched for gender, comorbidities, tobacco use and elective vs. emergent surgery. Differences in morbidity, mortality, hospital length of stay (LOS), and total inpatient cost were analyzed. Blood loss anemia was more common in Ob-III compared to Ob-I/II patients (OR = 1.2; 95% CI = 1.1−1.4); blood transfusions were less commonly required in Ob-I/II (OR = 0.8; 95% CI = 0.7−0.9) comparatively; Ob-I/II encountered pneumonia less frequently (OR = 0.9; 95% CI = 0.4−0.9), whereas myocardial infarction was more frequent (OR = 7.0; 95% CI = 2.1−23.6) compared to N-Ob patients. Acute renal failure is more frequent in Ob-I/II (OR = 1.2; 95% CI = 1.0−1.3) and Ob-III (OR = 1.8; 95% CI = 1.6−1.9) compared to the N-Ob cohort. LOS was higher in N-Ob (13.1 ± 12.8 days) and Ob-III (13.5 ± 12.4 d) compared to Ob-I/II cohort (11.8 ± 10.1 d; p < 0.001). Mortality was 2.8%, 1.4%, and 2.9% (p < 0.001) for N-Ob, Ob-I/II, and Ob-III, respectively. Hospital charges were $22,025 higher in the Ob-III cohort. Ob-I/II is protective against peri-operative complications and death, whereas hospital cost is substantially higher in Ob-III patients undergoing BKAs.

The Kenevo microprocessor-controlled prosthetic knee compared with non-microprocessor-controlled knees in individuals older than 65 years in Sweden: A cost-effectiveness and budget-impact analysis

BACKGROUND

Growing evidence suggests that individuals with transfemoral amputation or knee disarticulation using a prosthesis equipped with a microprocessor-controlled knee (MPK) benefit from enhanced mobility and safety, including less falls. In elderly individuals, high mortality rates are assumed to reduce the expected useful life of MPKs, and this raises concerns regarding their economic effectiveness.

OBJECTIVE

To investigate the cost-effectiveness and budget impact of the Kenevo/MPK (Ottobock, Germany) compared with non-microprocessor-controlled knees (NMPKs) in people older than 65 years at the time of transfemoral amputation/knee disarticulation, from a Swedish payer's perspective.

METHODS

A decision-analytic model was developed to conduct the economic analysis of the Kenevo/MPK. Model parameters were derived from Swedish databases and published literature. Univariate and probabilistic sensitivity analyses were performed to explore parameter uncertainty.

RESULTS

Compared with NMPKs, the Kenevo/MPK reduced the frequency of hospitalizations by 137 per 1,000 person years while the frequency of fatal falls was reduced by 19 per 1,000 person-years in the simulation. Over a 25-year time horizon, the incremental cost-effectiveness ratio was EUR11,369 per quality-adjusted life year. The probability of the MPK being cost-effective at a threshold of EUR40,000 per quality-adjusted life year was 99%. The 5-year budget impact model predicted an increase in payer expenditure of EUR1.76 million if all new patients received a Kenevo/MPK, and 50% of current NMPK users switched to the MPK.

CONCLUSIONS

Results of the modeling suggest that the Kenevo/MPK is likely to be cost-effective for elderly individuals, primarily because of a reduction in falls.

Symmetry Function: The Differences between Active and Non-Active Above-the-Knee Amputees

The number of patients with unilateral above-knee amputation (AKA) due to non-vascular causes has remained stable over the years, at 0.92 per 1000 people per year. Post-AKA individuals are at risk of experiencing a higher incidence of chronic pain. Post rehabilitation, it is estimated that between 16−62% of patients with musculoskeletal disabilities fail to meet the minimum criteria for physical activity in comparison to a healthy population. The current study included 14 participants (11 men and 3 women) with a mean age of 46.1 ± 14.2 years, body height of 1.76 ± 0.09 m, and weight of 79.6 ± 18.3 kg, who were all post-unilateral above-the-knee amputees. Patients in the study were divided into two groups: active (AC) and non-active (NAC). This study was conducted in a certified Laboratory of Biomechanical Analysis using the BTS Smart-E system (BTS Bioengineering). In order to investigate the symmetry function (SF) of gait, the only measurements included were the time series assessment of gait variables defining pelvic and lower limb joint motion and ground reaction forces (GRF). Both groups had an asymmetrical gait pattern with a different magnitude and relative position in the gait cycle, which was revealed by SF. The differences in terms of median, minimum, and maximum were statistically significant (p < 0.05), with SF ranging from −25 to 24% for the AC group and from 43 to 77% (59% on average) for the NAC group. The AC’s pattern was more symmetrical compared to the NAC’s pattern, especially in the case of pelvic and hip joint motion.

Contemporary Outcomes of Transfemoral Amputation After Total Knee Arthroplasty

BACKGROUND

Transfemoral amputation (TFA) is a salvage procedure for unreconstructable failed total knee arthroplasty (TKA). Prior studies have reported poor outcomes, patient survival, and prosthetic use. The purpose of this study was to analyze patient outcomes and prosthetic utilization in a contemporary group of patients undergoing TFA in the setting of a TKA.

METHODS

We reviewed 112 patients undergoing TFA with a prior TKA. Indications for amputation and postoperative functional measures were captured through chart review. Patients were contacted by survey to assess the quality of life. The mean follow-up after TFA was 4 years.

RESULTS

Amputations were performed for a chronically infected TKA (n = 87, 78%) and an ischemic limb without signs of an infected TKA (n = 22, 20%). The 10-year survival after TFA was 21%. Of the patients not lost to follow-up, 53 (47%) patients were fitted for a prosthesis. Patients who underwent a TFA after the year 2000 were more likely to be fit for a prosthesis (odds ratio 7.27, P < .01); however, patients were likely to be ambulatory before TFA than after TFA (odds ratio 3.68, P < .01). After TFA, the mean 12-Item Short Form Survey scores for the mental and physical components were 54 ± 13 and 34 ± 7, with no difference in scores between patients fitted for a prosthesis and those who were not (P > .05).

CONCLUSION

Patients undergoing a TFA after TKA due to failure of the TKA are more likely to be fit for a prosthesis; however, they reported no better quality of life and satisfaction compared with patients not fit for a prosthesis.

LEVELS OF EVIDENCE

Level III, Therapeutic.

Impacts of Microprocessor-Controlled Versus Non-microprocessor-Controlled Prosthetic Knee Joints Among Transfemoral Amputees on Functional Outcomes: A Comparative Study

INTRODUCTION

Selecting a prosthetic knee mechanism is an important part of transfemoral (TF) amputee rehabilitation. Prosthetic knee joint selection depends on the users' gait and their energy consumption. This study compares the feedback of transfemoral prosthesis users based on the prosthetic knee design self-reporting responses using the Prosthetic Evaluation Questionnaire (PEQ) outcome measure.

OBJECTIVE

This study aims to assess the impact of using a microprocessor-controlled prosthetic knee (MCPK) compared with a non-microprocessor-controlled prosthetic knee (NMCPK); feedback on the amputee usage can improve the clinical decision for proper prosthetic knee joint selection.

METHODS

This is a cross-sectional study with a total of 76 adult unilateral transfemoral amputees classified into two groups. The participants in the first group (38) used the MCPK (Genium, Otto Bock, Minneapolis, MN, USA), and the participants in the second group (38) used the NMCPK (hydraulic and total knee joints). Enrolment was based on a sequence of appointments where all participants answered the PEQ, with different subscale questions including utility (UT), sounds (SO), appearance (AP), residual limb health (RL), frustration (FR), perceived response (PR), social burden (SB), ambulation (AM), and quality of life (QoL). PEQ was filled out during the follow-up appointments at the prosthetic clinic through a visual analog scale (VAS). All data entered into a database were analyzed.

RESULT

The MCPK participants have significantly improved utility, appearance, ambulation, and total PEQ score, the same results as the male participants. Middle-adulthood (25-40 years) MCPK participants have a significant p-value in the score of utility, frustration, ambulation, and total PEQ score compared to early-adulthood (18-24 years) and late-adulthood (41-60 years) participants. Also, there was a significant improvement in the p-value in ambulation scores in participants using MCPK with amputations caused by diseases compared to amputations caused by trauma and congenital cause.

CONCLUSION

Transfemoral amputee prosthesis utility, natural gait, and ambulation improved when using MCPK compared to when using NMCPK during prosthetic rehabilitation.

Microprocessor knee technology reduces odds of incurring an injurious fall for individuals with diabetic/dysvascular amputation

Individuals with lower limb amputation have a high incidence of falls. An above-the-knee amputation and diabetes/vascular disease are both risk factors for falls. Microprocessor knee (MPK) technology may reduce falls in this population. The objective was to determine the association of MPKs and reduced injurious falls. A retrospective analysis of injurious falls within a large, national outcomes database was conducted. Inclusion was limited to adult K3 ambulators with unilateral, transfemoral or knee disarticulation amputation due to diabetes/vascular disease. There were 744 out of 881 individuals that did not receive an MPK. Results showed that 16.3% of non-MPK users experienced an injurious fall compared to 7.3% of MPK users (p=0.007). Not having an MPK resulted in significantly increased odds (unadjusted: OR: 2.47, 95% CI: 1.26 - 4.83, p=0.009; adjusted for confounders: OR: 2.52, 95% CI: 1.28 - 4.94, p=0.007) of incurring an injurious fall over a 6-month period. In conclusion, the current study found use of an MPK strongly associated with reduced injurious falls in a population of patients with amputation due to diabetes/vascular disease. The findings strongly support the use of MPK technology to mitigate fall risk, and in particular injurious falls requiring medical intervention.

Impact of prostheses on quality of life and functional status of transfemoral amputees in Tanzania

Background

The rise of diabetes and traumatic injury has increased limb loss-related morbidity in low- and middle-income countries (LMICs). Despite this, the majority of amputees in LMICs have no access to prosthetic devices, and the magnitude of prosthesis impact on quality of life (QOL ) and function has not been quantified.

Objectives

Quantify the impact of prostheses on QOL and function in Tanzanian transfemoral amputees.

Method

A prospective cohort study was conducted. Transfemoral amputees at Muhimbili Orthopaedic Institute were assessed twice before and three times after prosthetic fitting using EuroQol-5D-3L (EQ-5D-3L), Prosthetic Limb Users Survey of Mobility (PLUS-M), 2-minute walk test (2MWT) and Physiologic Cost Index (PCI). Data were analysed for change over time. Subgroup analysis was performed for amputation aetiology (vascular or non-vascular) and prosthesis use.

Results

Amongst 30 patients, EQ-5D, PLUS-M and 2MWT improved after prosthesis provision (p < 0.001). EuroQol-5D increased from 0.48 to 0.85 at 1 year (p < 0.001). EuroQol-5D and 2MWT were higher in non-vascular subgroup (p < 0.030). At 1-year, 84% of non-vascular and 44% of vascular subgroups reported using their prosthesis (p = 0.068).

Conclusion

Prosthesis provision to transfemoral amputees in an LMIC improved QOL and function. This benefit was greater for non-vascular amputation aetiologies. Quality of life and function returned to pre-prosthesis levels with discontinued use of prosthesis.

Effects of Prosthetic Socket Design on Residual Femur Motion Using Dynamic Stereo X-Ray - A Preliminary Analysis

Individuals with transfemoral amputation experience relative motion between their residual limb and prosthetic socket, which can cause inefficient dynamic load transmission and secondary comorbidities that limit mobility. Accurately measuring the relative position and orientation of the residual limb relative to the prosthetic socket during dynamic activities can provide great insight into the complex mechanics of the socket/limb interface. Five participants with transfemoral amputation were recruited for this study. All participants had a well-fitting, ischial containment socket and were also fit with a compression/release stabilization socket. Participants underwent an 8-wk, randomized crossover trial to compare differences between socket types. Dynamic stereo x-ray was used to quantify three-dimensional residual bone kinematics relative to the prosthetic socket during treadmill walking at self-selected speed. Comfort, satisfaction, and utility were also assessed. There were no significant differences in relative femur kinematics between socket types in the three rotational degrees of freedom, as well as anterior-posterior and medial-lateral translation (p > 0.05). The ischial containment socket demonstrated significantly less proximal-distal translation (pistoning) of the femur compared to the compression/release stabilization socket during the gait cycle (p < 0.05), suggesting that the compression/release stabilization socket provided less control of the residual femur during distal translation. No significant differences in comfort and utility were found between socket types (p > 0.05). The quantitative, dynamic analytical tools used in the study were sensitive to distinguish differences in three-dimensional residual femur motion between two socket types, which can serve as a platform for future comparative effectiveness studies of socket technology.

Gait training using the Honda Walking Assist Device® for individuals with transfemoral amputation: A report of two cases

BACKGROUND

Independent walking is important for individuals who have undergone lower limb amputation. Recently, robot-assisted gait training has been widely used for individuals with abnormal gait. However, no study has evaluated the effect of the Honda Walking Assist Device® (HWA) on the gait of patients who have undergone transfemoral (TF) amputation.

OBJECTIVE

This study aimed to investigate the safety, feasibility, and effect of gait training using the HWA for individuals who underwent lower limb amputation.

METHODS

This study included two elderly patients who underwent TF amputation due to a nontraumatic reason. Gait training interventions using the HWA were performed for a week (5 training sessions). Self-selected walking speed (SWS), step length, cadence, hip kinematic parameters, and symmetricity of single support time ratios during SWS were measured before and after the HWA interventions.

RESULTS

SWS, step length, cadence, and hip angle range improved after the HWA interventions in both patients. Symmetricity of single support time ratios and maximum hip extension angle improved in patient 1, but not in patient 2. There were no adverse events in either patient.

CONCLUSIONS

Gait training using the HWA was safe and effective for improving the gait of two TF amputees.

Instrumented Four Square Step Test in Adults with Transfemoral Amputation: Test-Retest Reliability and Discriminant Validity between Two Types of Microprocessor Knees

Technology-based outcomes have recently been proposed to complement the standard Four Square Step Test (FSST) by providing a decomposition of the sequences and information about the stepping pattern. A test-retest study and a randomized crossover design have been used to determine immediate test-retest reliability and to assess discriminant validity, in persons with a unilateral transfemoral amputation, for the parameters computed by an instrumented version of the Four Square Step Test. Twenty adults, independent and unlimited community ambulators, with a unilateral transfemoral amputation, performed two Four Square Step Tests on a pressure mat first with a microprocessor knee, then, a few weeks later with another one. One of these prosthetic knees was acknowledged to be superior and to provide functional improvement. Test-retest, intraclass correlation coefficients and minimal detectable change at 95% confidence level were calculated for each variable. Paired samples t-tests were then used to identify differences between the two microprocessor knee systems. The test-retest reliability of most outcome measures was good to excellent. Few variables showed a systematic difference and a trend to improve between test 1 and test 2. When comparing both microprocessor knees, significant differences in the expected direction were observed, with interpretation in accordance with a functional improvement. Importantly, we highlighted that various strategies to improve the performance in the test might complexify the interpretation of the most detailed measurement. The instrumented Four Square Step test provides reliable measures with satisfactory test-retest reliability and discriminant validity in persons with unilateral transfemoral amputation.

Prosthetic use by persons with unilateral transfemoral amputation in a South African setting

BACKGROUND

Due to limitations in provision of prosthetic care in South Africa, a screening tool to select transfemoral prosthetic candidates has been implemented.

OBJECTIVE

To describe prosthetic services, use and mobility of people with transfemoral amputation, identified as prosthetic candidates through the Guidelines for Screening of Prosthetic Candidates: Lower Limb, and to identify variables that might influence prosthetic use and mobility.

DESIGN

Cross-sectional survey.

METHODS

The study population included all adults who received their first prosthesis from the Orthotic and Prosthetic Centre in the Western Cape between 1 June 2011 and 31 December 2014. Data were collected, with an adapted version of the Prosthetic Profile of the Amputee, from 43 participants, through telephonic interviews. Descriptive and inferential analysis, with the chi-square test, was done.

RESULTS

The majority of participants were older than 50 years (77%). Most participants (35; 81%) used their prosthesis; however, only 42% (18) used it daily. A significant association ( p = 0.000) was found between prosthetic rehabilitation and self-reported prosthetic walking distance. Less than half of participants received prosthetic rehabilitation and only 10 (30%) could walk 500 steps and more without resting.

CONCLUSION

Participants used their prosthetic leg, but experienced limitations in frequency of wear and mobility.

CLINICAL RELEVANCE

Current findings showed that participants' prosthetic mobility was curtailed. In less-resourced settings, carefully selecting prosthetic candidates may be necessary to provide access to services. Prosthetic provision is advised to be followed up with prosthetic rehabilitation for favourable mobility outcomes.

Functional rehabilitation of a person with transfemoral amputation through guided motor imagery: a case study

Background: Motor imagery (MI) is a mental technique, absent of physical movement, to foster movement patterns and relieve pain via a training model enacting the brain before the body. This case study assessed MI's efficacy in decreasing phantom limb pain and attaining functional gait and balance after lower extremity amputation. Description: The participant was a 71-year-old female with a transfemoral amputation seven years prior. She required a standard walker for ambulation. The participant underwent three sessions per week for four weeks of MI intervention, with immediate, post-test, and 1-week retention testing involving subjective and functional assessments. Intervention sessions involved quiet sitting with eyes closed while listening to the MI script. The scripts focused on functional movement patterns and tasks that were relevant to the participant, such as walking, balancing, and reaching. Each session's script focused on a different task. These scripts guided her through proper action and biomechanics of the skills to imagine herself moving safely and functionally. Outcomes: Short Form Berg Balance Scale and Tinetti Performance Oriented Mobility Assessment scores demonstrated clinically important and sustained improvement. Further, the participant reported decreased phantom limb pain and could walk a short distance independently for the first time in seven years. Discussion: MI is a time- and cost-effective, low-risk treatment option that decreased phantom pain and improved balance and functional gait in an individual with an amputation. The use of MI as an intervention for the rehabilitation of persons with amputation must be further examined.

The relationship between lumbar lordosis angle and low back pain in individuals with transfemoral amputation

BACKGROUND:

Low back pain is a common secondary disabling condition in the transfemoral amputee population. Transfemoral amputees are at risk of excessive lumbar lordosis; it has been suggested that increased lumbar lordosis may be associated with low back pain. However, the relationship between lumbar lordosis angle and low back pain has not yet been studied in this population.

OBJECTIVE:

To determine whether the extent of lumbar lordosis is associated with low back pain in transfemoral amputees.

STUDY DESIGN:

Case-control observational study.

METHODS:

Participants included eight transfemoral amputees without low back pain and nine transfemoral amputees with low back pain. Etiology of amputation was primarily trauma. All participants underwent lateral view radiographs of the lumbar spine, from which lumbar lordosis angle and sacral inclination angle were measured.

RESULTS:

Lumbar lordosis angle mean ± standard deviation was 46.1° ± 12.4° in participants with low back pain and 51.0° ± 12.6° in those without. Sacral inclination angle mean ± standard deviation was 38.3° ± 8.7° in participants with low back pain and 39.1° ± 7.5° in those without. There was no significant difference in lumbar lordosis angle or sacral inclination angle between participants with and without low back pain.

CONCLUSION:

This study suggests that increased lumbar lordosis angle and sacral inclination angle are not significantly associated with low back pain in transfemoral amputees of a primarily traumatic etiology.

CLINICAL RELEVANCE

Low back pain (LBP) is a common, disabling condition in transfemoral amputees. In the clinical setting, increased lumbar lordosis is implicated in LBP. This study does not support an association between increased lumbar lordosis and LBP; further study is needed to understand the increased prevalence of LBP in this population.

An Efficient Modelling-Simulation-Analysis Workflow to Investigate Stump-Socket Interaction Using Patient-Specific, Three-Dimensional, Continuum-Mechanical, Finite Element Residual Limb Models

The lack of an efficient modelling-simulation-analysis workflow for creating and utilising detailed subject-specific computational models is one of the key reasons why simulation-based approaches for analysing socket-stump interaction have not yet been successfully established. Herein, we propose a novel and efficient modelling-simulation-analysis workflow that uses commercial software for generating a detailed subject-specific, three-dimensional finite element model of an entire residual limb from Diffusion Tensor MRI images in <20 min. Moreover, to complete the modelling-simulation-analysis workflow, the generated subject-specific residual limb model is used within an implicit dynamic FE simulation of bipedal stance to predict the potential sites of deep tissue injury. For this purpose, a nonlinear hyperelastic, transversely isotropic skeletal muscle constitutive law containing a deep tissue injury model was implemented in LS-DYNA. To demonstrate the feasibility of the entire modelling-simulation-analysis workflow and the fact that detailed, anatomically realistic, multi-muscle models are superior to state-of-the-art, fused-muscle models, an implicit dynamic FE analysis of 2-h bipedal stance is carried out. By analysing the potential volume of damaged muscle tissue after donning an optimally-fitted and a misfitted socket, i.e., a socket whose volume was isotropically shrunk by 10%, we were able to highlight the differences between the detailed individual- and fused-muscle models. The results of the bipedal stance simulation showed that peak stresses in the fused-muscle model were four times lower when compared to the multi-muscle model. The peak interface stress in the individual-muscle model, at the end of bipedal stance analysis, was 2.63 times lower than that in the deep tissues of the stump. At the end of the bipedal stance analysis using the misfitted socket, the fused-muscle model predicted that 7.65% of the residual limb volume was injured, while the detailed-model predicted 16.03%. The proposed approach is not only limited to modelling residual limbs but also has applications in predicting the impact of plastic surgery, for detailed forward-dynamics simulations of normal musculoskeletal systems.

Biomechanical Parameters of Gait after Unilateral Above-knee Amputation. Current State of Research

The aim of this paper is to present the current state of research on gait parameters in people after unilateral amputation above the knee joint and to compare these gait parameters with those of healthy people. The relevant literature does not include any similar publications. Modern prostheses do not eliminate the asymmetry of gait, although its consequences are diminished. An above-knee amputation leads to significant differences in ground reaction force parameters (GRF) between the sound and amputated limb. The amputated limb is charac-te-rised by lower values of vertical and antero-posterior GRF parameters in comparison with the intact limb. Moreover, during the contact of the heel with the ground, the degree of hip joint flexion of the amputated limb decreases in comparison with the intact limb. Other symptoms of asymmetry between the limbs include asymmetry of pelvic movement in the transverse plane and of the range of movement in the ankle joint. De-creased muscle torque on the hip joint in the amputated limb additionally increases asymmetry of biome-chanical gait parameters after unilateral transfemoral amputation.

Bone Mineral Density Measurements Around Osseointegrated Implants: A Precision Study and Validation of Scan Protocol for Transfemoral Amputees

Visual evaluation of bone changes around an osseointegration (OI) implant in femoral amputees examined on plain radiographs shows that periprosthetic bone resorption takes place during the first years after OI surgery, but the bone mineral density (BMD) change has not been previously quantified by dual-energy X-ray absorptiometry (DXA). Precision is vital when monitoring BMD changes around implants, and thus the aim of this study was to evaluate the precision and feasibility of a scan protocol for BMD measurements in proximity of OI implants. The proximal part of 2 human cadaveric femoral bones (specimens A and B) with OI implants were mounted in a positioning jig and DXA scans were repeated 5 times in increments of 5° from neutral (0°) to 20° flexion and rotation. BMD changes as a result of change in leg position were evaluated. Repeated patient examinations (n = 20) were conducted in a clinical setting and the precision error was calculated for each of 7 periprosthetic custom-made regions of interest (ROIs). The precision of cadaveric BMD measurements in neutral position was <3.3%. Even 5° flexion or rotation in femur position caused significant changes in average BMD (p <0.04). Depending on ROI, the percentage of coefficient of variation (%CV) and average BMD was <6% at 10° flexion and rotation. At 20° flexion, %CV increased up to 12.7% and average BMD increased up to 9.9%. The clinical short-term precision root mean square standard deviation ranged from 0.031 g/cm² to 0.047 g/cm² and %CV ranged from 3.12% to 6.57% depending on ROI. Simulated hip flexion or rotation of the femur affected periprosthetic BMD measurements around OI implants in cadaveric femoral bones, which stresses the importance of a reproducible set-up during DXA scans to reduce measurement errors caused by variation in leg position. Adherence to the scan protocol with a relaxed position of the residual limb resulted in an acceptable short-term precision below 6.6%.

The process of becoming a user of an osseointegrated prosthesis following transfemoral amputation: a qualitative study

PURPOSE

To investigate what characterizes the process of becoming a user of an osseointegrated prosthesis following transfemoral amputation.

METHOD

The study is based on the descriptive phenomenological framework Reflective Lifeworld Research. Data were collected through in-depth interviews with seven participants who had undergone transfemoral implant surgery and currently used their osseointegrated prosthesis. Data were analyzed according to the guidelines given in Reflective Lifeworld Research.

RESULTS

The essential meaning of becoming a user of an osseointegrated prosthesis is characterized by determination to achieve rehabilitation results as well as a struggle to get familiar with the new prosthesis. When familiar with the prosthesis, participants begin to experience radical improvements in their everyday life, compared to their life with the socket suspended prosthesis. The essential meaning is elaborated on in four constituents: Determination to achieve rehabilitation results with the short training prosthesis, struggling to get familiar with the osseointegrated prosthesis, experiencing improvements in everyday life and reconnecting with one's prior self-perception.

CONCLUSION

All the participants experienced increased action space and a more positive outlook on life. However, it took determination and stamina to become a user of an osseointegrated prosthesis, and participants faced several challenges throughout this process. Consequently, it remains important to raise awareness of the difficulties faced during this process. Implications for Rehabilitation The findings from this study suggest an increased healthcare support to users of an transfemoral osseointegrated prosthesis in the period of rehabilitation and adjustment, as the results of being able to use the osseointegrated prosthesis may outweigh the obstacles of getting there. Implementation of long-term follow-up and psychosocial support initiatives may improve the adjustment process following osseointegration. Support of patients with an osseointegrated prosthesis may be facilitated through formation of specific rehabilitation groups together with increased use of information technology such as social media and relevant online communities which provide forums for interaction and dialog with people in similar situations.

Total Blood Loss After Transfemoral Amputations Is Twice the Intraoperative Loss: An Observational Cohort Study of 81 Nontraumatic Amputations

Introduction:

Underestimation of the actual blood loss in patients undergoing nontraumatic transfemoral amputation (TFA) can impact negatively on outcome in these often frail patients, with very limited physiological reserves. The primary aim of this study is to estimate the total blood loss (TBL) after TFA, and second, to evaluate the impact of blood loss on 30-day mortality and medical complications.

Methods:

A single-center retrospective cohort study conducted from 2013 to 2015. The TBL was calculated on the fourth postoperative day. It was based on the hemoglobin levels, transfusions, and the estimated blood volume.

Results:

Eighty-one patients undergoing TFA were included for final analysis. The median TBL was 964 mL (interquartile range [IQR]: 443-1558). The intraoperative blood loss (OBL) was 400 mL (IQR: 200-500). The median difference between TBL and OBL was 688 mL (IQR: 124-1075). The patient received red blood cell (RBC) transfusion of a median amount of 2 units. Higher number of transfusions (>2) did not impact the outcome. From multivariable analysis, it was evident that the TBL increased significantly in patients with renal disease prior to surgery, (P = .034). The TBL itself was not independently associated with increased 30-day mortality or medical complications.

Conclusion:

The TBL after TFAs is significantly greater than the volume estimated intraoperatively and increases significantly in the presence of renal disease prior to surgery. An increased TBL and requirement for RBC transfusion is not directly associated with 30-day mortality or medical complications. A high vigilance for anemia seems advisable when planning for TFA surgery. Research on optimum blood conservation and transfusion strategies during TFA is warranted.

Whole Body Awareness for Controlling a Robotic Transfemoral Prosthesis

Restoring locomotion functionality of transfemoral amputees is essential for early rehabilitation treatment and for preserving mobility and independence in daily life. Research in wearable robotics fostered the development of innovative active mechatronic lower-limb prostheses designed with the goal to reduce the cognitive and physical effort of lower-limb amputees in rehabilitation and daily life activities. To ensure benefits to the users, active mechatronic prostheses are expected to be aware of the user intention and properly interact in a closed human-in-the-loop paradigm. In the state of the art various cognitive interfaces have been proposed to online decode the user's intention. Electromyography in combination with mechanical sensing such as inertial or pressure sensors is a widely adopted solution for driving active mechatronic prostheses. In this framework, researchers also explored targeted muscles re-innervation for an objective-oriented surgical amputation promoting wider usability of active prostheses. However, information kept by the neural component of the cognitive interface deteriorates in a prolonged use scenario due to electrodes-related issues, thereby undermining the correct functionality of the active prosthesis. The objective of this work is to present a novel controller for an active transfemoral prosthesis based on whole body awareness relying on a wireless distributed non-invasive sensory apparatus acting as cognitive interface. A finite-state machine controller based on signals monitored from the wearable interface performs subject-independent intention detection of functional tasks such as ground level walking, stair ascent, and sit-to-stand maneuvres and their main sub-phases. Experimental activities carried out with four transfemoral amputees (among them one dysvascular) demonstrated high reliability of the controller capable of providing 100% accuracy rate in treadmill walking even for weak subjects and low walking speeds. The minimum success rate was of 94.8% in performing sit-to-stand tasks. All the participants showed high confidence in using the transfemoral active prosthesis even without training period thanks to intuitiveness of the whole body awareness controller.

Northwestern University Flexible Subischial Vacuum Socket for persons with transfemoral amputation: Part 2 Description and Preliminary evaluation

BACKGROUND

Current transfemoral prosthetic sockets are problematic as they restrict function, lack comfort, and cause residual limb problems. Development of a subischial socket with lower proximal trim lines is an appealing way to address this problem and may contribute to improving quality of life of persons with transfemoral amputation.

OBJECTIVES

The purpose of this study was to illustrate the use of a new subischial socket in two subjects.

STUDY DESIGN

Case series.

METHODS

Two unilateral transfemoral prosthesis users participated in preliminary socket evaluations comparing functional performance of the new subischial socket to ischial containment sockets. Testing included gait analysis, socket comfort score, and performance-based clinical outcome measures (Rapid-Sit-To-Stand, Four-Square-Step-Test, and Agility T-Test).

RESULTS

For both subjects, comfort was better in the subischial socket, while gait and clinical outcomes were generally comparable between sockets.

CONCLUSION

While these evaluations are promising regarding the ability to function in this new socket design, more definitive evaluation is needed. Clinical relevance Using gait analysis, socket comfort score and performance-based outcome measures, use of the Northwestern University Flexible Subischial Vaccum Socket was evaluated in two transfemoral prosthesis users. Socket comfort improved for both subjects with comparable function compared to ischial containment sockets.

Northwestern University Flexible Subischial Vacuum Socket for persons with transfemoral amputation-Part 1: Description of technique

BACKGROUND

Current transfemoral prosthetic sockets restrict function, lack comfort, and cause residual limb problems. Lower proximal trim lines are an appealing way to address this problem. Development of a more comfortable and possibly functional subischial socket may contribute to improving quality of life of persons with transfemoral amputation.

OBJECTIVES

The purpose of this study was to (1) describe the design and fabrication of a new subischial socket and (2) describe efforts to teach this technique.

STUDY DESIGN

Development project.

METHODS

Socket development involved defining the following: subject and liner selection, residual limb evaluation, casting, positive mold rectification, check socket fitting, definitive socket fabrication, and troubleshooting of socket fit. Three hands-on workshops to teach the socket were piloted and attended by 30 certified prosthetists and their patient models.

RESULTS

Patient models responded positively to the comfort, range of motion, and stability of the new socket while prosthetists described the technique as "straight forward, reproducible."

CONCLUSION

To our knowledge, this is the first attempt to create a teachable subischial socket, and while it appears promising, more definitive evaluation is needed. Clinical relevance We developed the Northwestern University Flexible Subischial Vacuum (NU-FlexSIV) Socket as a more comfortable alternative to current transfemoral sockets and demonstrated that it could be taught successfully to prosthetists.

Ultrasonographic measurement of the femoral cartilage thickness in patients with transfemoral amputation

OBJECTIVE

To compare the distal femoral cartilage thickness of the non-amputee sides in patients who had unilateral transfemoral amputation with those of healthy subjects by using ultrasound.

METHODS

Thirty transfemoral amputees (27 male, 3 female) and 30 age-, sex-, and body mass index-matched healthy controls were included. Functional usage of the prosthesis was evaluated by using Houghton score. The cartilage thickness was measured from the following midpoints; medial femoral condyle (MFC), intercondylar area, and lateral femoral condyle.

RESULTS

Thirty patients with unilateral transfemoral amputation (mean age; 38.6 ± 9.5 years) and 30 healthy controls (mean age; 38.4 ± 9.4 years) were included. Although femoral cartilage thicknesses were found to be lower for all measurements in the amputees, the difference reached significance only in the MFC (p= 0.031). In the patient group, cartilage thickness values did not correlate with age, duration of amputation, daily walking time, stump length or Houghton score.

CONCLUSION

The distal femoral cartilage thickness seems to be decreased medially on the non-amputee sides of the transfemoral amputees when compared with the healthy subjects. Further studies concerning the follow-up designs, functional parameters and osteoarthritis scales are awaited.

Multiple Neuromas Cause Painful "Jumping Stump" in a Transfemoral Amputee: A Case Report

Painful "jumping stump" is an uncommon but very disturbing complication postamputation. This condition is one of the movement disorder entities resulting from peripheral nerve pathology, often known as "peripherally induced movement disorders." Previously case reports have been written about painful and nonpainful incidence of "jumping stump"; however, only the earliest "jumping stump" article in 1852 suspected that neuromas might influence the involuntary movement. In this study, we describe a 38-year-old man with bilateral transfemoral amputee who suffered from painful "jumping stump" with multiple neuromas confirmed by imaging. He was treated successfully by ultrasound-guided phenol injection into the sciatic neuroma stalks. The pathophysiology of jumping stump and its possible association with neuroma are briefly discussed.

Lower-limb amputation and body weight changes in men

Little is known about the relationship between lower-limb amputation (LLA) and subsequent changes in body weight. We conducted a retrospective cohort study using clinical and administrative databases to identify and follow weight changes in 759 males with amputation (partial foot amputation [PFA], n = 396; transtibial amputation [TTA], n = 267; and transfemoral amputation [TFA], n = 96) and 3,790 nondisabled persons frequency-matched (5:1) on age, body mass index, diabetes, and calendar year from eight Department of Veterans Affairs medical care facilities in the Pacific Northwest. We estimated and compared longitudinal percent weight change from baseline during up to 39 mo of follow-up in participants with and without amputation. Weight gain in the 2 yr after amputation was significantly more in men with an amputation than without, and in men with a TTA or TFA (8%-9% increase) than in men with a PFA (3%-6% increase). Generally, percent weight gain peaked at 2 yr and was followed by some weight loss in the third year. These findings indicate that LLA is often followed by clinically important weight gain. Future studies are needed to better understand the reasons for weight gain and to identify intervention strategies to prevent excess weight gain and the deleterious consequences that may ensue.

Benefits of microprocessor-controlled prosthetic knees to limited community ambulators: systematic review

The benefits of microprocessor-controlled prosthetic knees (MPKs) have been well established in community ambulators (Medicare Functional Classification Level [MFCL]-3) with a transfemoral amputation (TFA). A systematic review of the literature was performed to analyze whether limited community ambulators (MFCL-2) may also benefit from using an MPK in safety, performance-based function and mobility, and perceived function and satisfaction. We searched 10 scientific databases for clinical trials with MPKs and identified six publications with 57 subjects with TFA and MFCL-2 mobility grade. Using the criteria of a Cochrane Review on prosthetic components, we rated methodological quality moderate in four publications and low in two publications. MPK use may significantly reduce uncontrolled falls by up to 80% as well as significantly improve indicators of fall risk. Performance-based outcome measures suggest that persons with MFCL-2 mobility grade may be able to walk about 14% to 25% faster on level ground, be around 20% quicker on uneven surfaces, and descend a slope almost 30% faster when using an MPK. The results of this systematic review suggest that trial fittings may be used to determine whether or not individuals with TFA and MFCL-2 mobility grade benefit from MPK use. Criteria for patient selection and assessment of trial fitting success or failure are proposed.

Vibrotactile evaluation: osseointegrated versus socket-suspended transfemoral prostheses

This study investigated detection thresholds of vibrometric stimuli in patients with transfemoral amputation supplied with osseointegrated (OI) and socket-suspended prostheses. It included 17 patients tested preoperatively with socket-suspended prostheses and after 2 yr with OI prostheses and a control group (n = 17) using socket-suspended prostheses, evaluated once. Assessments on the prosthetic and intact feet were conducted at six frequencies (8, 16, 32, 64, 125, and 250 Hz). Furthermore, measurements were conducted to investigate how vibrometric signals are transmitted through a test prosthesis. The results showed that the OI group had improved ability to detect vibrations through the prosthesis at 125 Hz (p = 0.01) at follow-up compared with the preoperative measurement. Compared with the control group, the OI group at follow-up had better ability to detect high frequency vibrations through the prosthesis (125 Hz, p = 0.02; 250 Hz, p = 0.03). The vibrometric signal transmitted through the test prosthesis was reduced at 8, 125, and 250 Hz but was amplified at 16, 32, and 64 Hz. Differences between the OI and the control groups were found in the highest frequencies in which the test prosthesis showed reduction of the vibrometric signal. The study provides insight into the mechanisms of vibration transmission between the exterior and bone-anchored as well as socket-suspended amputation prostheses.

Home-based treadmill training to improve gait performance in persons with a chronic transfemoral amputation

OBJECTIVE

To investigate the effectiveness of a home-based multiple-speed treadmill training program to improve gait performance in persons with a transfemoral amputation (TFA).

DESIGN

Repeated measures.

SETTING

Research laboratory.

PARTICIPANTS

Individuals with a TFA (N=8) who had undergone a unilateral amputation at least 3 years prior as a result of limb trauma or cancer.

INTERVENTION

Home-based treadmill walking for a total of 30 minutes a day, 3 days per week for 8 weeks. Each 30-minute training session involved 5 cycles of walking for 2 minutes at 3 speeds.

MAIN OUTCOME MEASURES

Participants were tested pretraining and after 4 and 8 weeks of training. The primary measures were temporal-spatial gait performance (symmetry ratios for stance phase duration and step length), physiological gait performance (energy expenditure and energy cost), and functional gait performance (self-selected walking speed [SSWS], maximum walking speed [MWS], and 2-minute walk test [2MWT]).

RESULTS

Eight weeks of home-based training improved temporal-spatial gait symmetry at SSWS but not at MWS. A relative interlimb increase in stance duration for the prosthetic limb and proportionally greater increases in step length for the limb taking shorter steps produced the improved symmetry. The training effect was significant for the step length symmetry ratio within the first 4 weeks of the program. Energy expenditure decreased progressively during the training with nearly 10% improvement observed across the range of walking speeds. SSWS, MWS, and 2MWT all increased by 16% to 20%.

CONCLUSIONS

Home-based treadmill walking is an effective method to improve gait performance in persons with TFA. The results support the application of training interventions beyond the initial rehabilitation phase, even in individuals considered highly functional.

Prosthetic fitting, use, and satisfaction following lower-limb amputation: A prospective study

Providing a satisfactory, functional prosthesis following lower-limb amputation is a primary goal of rehabilitation. The objectives of this study were to describe the rate of successful prosthetic fitting over a 12 mo period; describe prosthetic use after amputation; and determine factors associated with greater prosthetic fitting, function, and satisfaction. The study design was a multicenter prospective cohort study of individuals undergoing their first major lower-limb amputation because of vascular disease and/or diabetes. At 4 mo, unsuccessful prosthetic fitting was significantly associated with depression, prior arterial reconstruction, diabetes, and pain in the residual limb. At 12 mo, 92% of all subjects were fit with a prosthetic limb and individuals with transfemoral amputation were significantly less likely to have a prosthesis fit. Age older than 55 yr, diagnosis of a major depressive episode, and history of renal dialysis were associated with fewer hours of prosthetic walking. Subjects who were older, had experienced a major depressive episode, and/or were diagnosed with chronic obstructive pulmonary disease had greater functional restriction. Thus, while most individuals achieve successful prosthetic fitting by 1 yr following a first major nontraumatic lower-limb amputation, a number of medical variables and psychosocial factors are associated with prosthetic fitting, utilization, and function.