Above knee amputee

Existing controllers for robotic powered prostheses regulate the prosthesis speed, timing, and energy generation using predefined position or torque trajectories. This approach enables climbing stairs step-over-step. However, it does not provide amputees with direct volitional control of the robotic prosthesis, a functionality necessary to restore full mobility to the user. Here we show that proportional electromyographic (EMG) control of the prosthesis knee torque enables volitional control of a powered knee prosthesis during stair climbing...

Powered lower-limb prostheses have the potential to improve amputee mobility by closely imitating the biomechanical function of the missing biological leg. To accomplish this goal, powered prostheses need controllers that can seamlessly adapt to the ambulation activity intended by the user. Most powered prosthesis control architectures address this issue by switching between specific controllers for each activity. This approach requires online classification of the intended ambulation activity. Unfortunately, any misclassification can cause the prosthesis to perform a different movement than the user expects, increasing the likelihood of falls and injuries...

Ambulation in everyday life requires walking at variable speeds, variable inclines, and variable terrains. Powered prostheses aim to provide this adaptability through control of the actuated joints. Some powered prosthesis controllers can adapt to discrete changes in speed and incline but require manual tuning to determine the control parameters, leading to poor clinical viability. Other data-driven controllers can continuously adapt to changes in speed and incline but do so by imposing the same non-amputee gait patterns for all amputee subjects, which does not consider subjective preferences and differing clinical needs of users...

The study aims to construct an inertial measuring system for the application of amputee subjects wearing a prosthesis. A new computation scheme to process inertial data by installing seven wireless inertial sensors on the lower limbs was implemented and validated by comparing it with an optical motion capture system. We applied this system to amputees to verify its performance for gait analysis. The gait parameters are evaluated to objectively assess the amputees' prosthesis-wearing status. The Madgwick algorithm was used in the study to correct the angular velocity deviation using acceleration data and convert it to quaternion...

INTRODUCTION: Patients with above-knee amputations (AKA) are normally treated with the traditional socket-mounted prosthesis (SMP), which is associated with a high incidence of problems. Osseointegration has been proposed as a promising option for avoiding many common SMP drawbacks. Several concerns have arisen regarding amputee osseointegration, however, mainly with respect to infection. We report on the safety of a single-stage osseointegration protocol using an antibiotic-loaded hydrogel to coat the intramedullary implant...

Powered knee-ankle prostheses can offer benefits over conventional passive devices during stair locomotion by providing biomimetic net-positive work and active control of joint angles. However, many modern control approaches for stair ascent and descent are often limited by time-consuming hand-tuning of user/task-specific parameters, predefined trajectories that remove user volition, or heuristic approaches that cannot be applied to both stair ascent and descent. This work presents a phase-based hybrid kinematic and impedance controller (HKIC) that allows for semi-volitional, biomimetic stair ascent and descent at a variety of step heights...

Amputees typically experience changes in residual limb volume in their daily lives. It causes an uncomfortable fit of the socket by applying high pressure on the sensitive area of the residual limb or by loosening the socket. In this study, we developed a transfemoral prosthetic socket for above-the-knee amputees that ensures a good socket fit by maintaining uniform and constant contact pressure despite volume changes in the residual limb. The socket has two air bladders in the posterior femoral region, and the pneumatic controller is located on the tibia of the prosthesis...

Robotic knee-ankle prostheses have often fallen short relative to passive microprocessor prostheses in time-based clinical outcome tests. User ambulation endurance is an alternative clinical outcome metric that may better highlight the benefits of robotic prostheses. However, previous studies were unable to show endurance benefits due to inaccurate high-level classification, discretized mid-level control, and insufficiently difficult ambulation tasks. In this case study, we present a phase-based mid-level prosthesis controller which yields biomimetic joint kinematics and kinetics that adjust to suit a continuum of tasks...

Passive prosthetic legs require undesirable compensations from amputee users to avoid stubbing obstacles and stairsteps. Powered prostheses can reduce those compensations by restoring normative joint biomechanics, but the absence of user proprioception and volitional control combined with the absence of environmental awareness by the prosthesis increases the risk of collisions. This paper presents a novel stub avoidance controller that automatically adjusts prosthetic knee/ankle kinematics based on suprasensory measurements of environmental distance from a small, lightweight, low-power, low-cost ultrasonic sensor mounted above the prosthetic ankle...

BACKGROUND: Problems related to quality of life and body images of amputee patients are important. AIMS: This study was performed to assess body image and quality of life with problems experienced of patients with lower limb amputation. MATERIALS AND METHODS: This study was performed using mixed quantitative dominant study design. The study was carried out in orthopedics and cardiovascular surgery units of a university hospital. Quantitative data were collected from 30 patients via questionnaires including the Short Form-36 Quality of Life (SF-36 QoL) and Amputee Body Image Scale (ABIS) tools...

TMR (targeted muscle reinnervation) or RPNI (regenerative peripheral nerve interface) have been the standard after nerve injuries. In this case report, we explain our approach in combining these two techniques (TMRpni) for a patient undergoing left above-the-knee amputation. Using this method, both phantom and nerve pain were reduced in our patient's case. As this technique becomes more well understood and widely adopted, amputee patients may achieve a greater quality of life post operation.

Above-knee amputees were capable of weight-bearing symmetry during stand-to-sit transitions when using a powered prosthesis.

BACKGROUND: Conventional hip disarticulation prostheses (HDPs) are passive devices with separate joint structures, limiting amputees' ability to control and resulting in abnormal gait patterns. This study introduces a new HDP integrating the hip and knee joints for amputees' natural gait. METHODS: The new HDP restores the physiological rotation center of the hip with a remote center of motion (RCM) structure, and simulates the knee motion with a four-bar structure...

BACKGROUND: A 72-year-old man with a history of delayed presentation for severe right lower extremity burns underwent through-knee amputation complicated by periprosthetic distal femur osteomyelitis. Subsequent transfemoral amputation was complicated by Stage IVB Cierny-Mader osteomyelitis despite appropriate medical and surgical treatment. METHODS: Due to the presence of threatened proximal femur intramedullary nail from prior intertrochanteric femur fracture, inability to further shorten femur, and lack of local soft-tissue options, we performed soft tissue reconstruction with free gracilis flap...

BACKGROUND: The relationship between acute combat-related traumatic injury (CRTI) to coronary flow reserve (CFR) and subclinical cardiovascular risk have not been examined and was the primary aim of this study. METHODS AND RESULTS: UK combat veterans from the ADVANCE cohort study (UK-Afghanistan War 2003-14) with traumatic limb amputations were compared to injured non-amputees and to a group of uninjured veterans from the same conflict. Subclinical cardiovascular risk measures included fasted blood atherogenic index of plasma (AIP), triglyceride-glucose index (TyG; insulin resistance), the neutrophil-lymphocyte ratio (NLR) and high-sensitivity C-reactive protein (hs-CRP; vascular inflammation), body mass index (BMI) and visceral fat volume (dual-energy X-ray absorptiometry) and 6-min walk distance (6MWD; physical performance)...

INTRODUCTION: The purpose of this study was (a) to create a profile of the running performances of male amputee soccer players in different speed zones, (b) to investigate the relationship between heart rate (HR) and running distance in two soccer matches, and (c) to study the effect of the level of amputation on the running distance covered during a match. MATERIAL AND METHODS: The participants were male amputee soccer players ( n = 10, Greek, n = 5; Belgian, n = 5) who played two international, friendly matches...

The aim of this review article is to appraise the design and functionality of above-knee prosthetic legs. So far, various transfemoral prosthetic legs are found to offer a stable gait to amputees but are limited to laboratories. The commercially available prosthetic legs are not reliable and comfortable enough to satisfy amputees. There is a dire need for creating a powered prosthetic knee joint that could address amputees' requirements. To pinpoint the gap in transfemoral prosthetic legs, prosthetic knee unit model designs, control frameworks, kinematics, and gait evaluations are concentrated...

BACKGROUND: Patients undergoing lower extremity amputation after trauma are at high risk of venous thromboembolism. Practice variations persist regarding the optimal pharmacologic agent for venous thromboembolism prophylaxis in this patient population. We aimed to compare the efficacy of unfractionated heparin versus low-molecular-weight heparin in preventing venous thromboembolism. METHODS: Using the 2013 to 2019 American College of Surgeons Pediatric Trauma Quality Improvement Program database, all trauma patients (≥18) who underwent lower limb amputation and received venous thromboembolism thromboprophylaxis in the form of unfractionated heparin or low-molecular-weight heparin were included...

BACKGROUND: Hip fractures in amputees pose a significant challenge for the orthopedic surgeon due to technical difficulties and there is no standardisation in their management. Their treatment is consequently left to the surgeon's ingenuity. The aim of this study is to describe the clinical characteristics and outcome of a series of hip fractures in lower limb amputees. METHODS: A total of 12 patients and 15 hip fractures in lower limb amputees were included. Amputations below the malleoli and prosthetic surgery due to osteoarthritis constitute the exclusion criteria...

BACKGROUND: The Lower Extremity Amputation Protocol (LEAP) is a multidisciplinary enhanced recovery after surgery pathway for vascular amputees. The objective of this study was to examine feasibility and outcomes of community-wide implementation of LEAP. METHODS: LEAP was implemented at three safety net hospitals for patients with peripheral artery disease or diabetes requiring major lower extremity amputation. Patients who underwent LEAP (LEAP) were matched 1:1 with retrospective controls (NOLEAP) on hospital location, need for initial guillotine amputation, and final amputation type (above vs below knee)...