View clinical trials related to Lower Extremity Amputation.
Filter by:The agonist-antagonist myoneural interface (AMI) construct, known as the Ewing amputation at the trans-tibial level, has been shown to create a bi-directional neural communication platform as a means of controlling and interpreting proprioceptive feedback from a prosthetic joint. In AMI constructs, agonist-antagonist muscles are mechanically coupled within the residual limb, and volitional contraction of an agonist passively stretches that muscle's antagonist. The natural neural responses from muscle spindles within both muscles are then interpreted by the central nervous system as sensations of joint position and speed, associated with movement of the prosthesis. The aim of this research protocol is to evaluate the electromyographic and kinematic patterns of participants who have undergone unilateral lower extremity Ewing Amputation in order to determine how similar their residual limb data is when compared to their intact limb data. A secondary aim of this research may include comparison of the Ewing participant cohort's biomechanical patterns to a similar cohort of participants who have undergone standard amputation. The investigators hypothesize that the affected limb of patients with the Ewing procedure will demonstrate a pattern of electromyographic activation of their AMI constructs and kinematic data that recapitulates the pattern seen in their intact limb. The investigators secondarily hypothesize that the kinematic assessment of Ewing Amputation patients will demonstrate patterns that are significantly more physiologic than those witnessed in similar assessments of standard amputees.
This is an observational, prospective multicentric study designed to develop medical knowledge. The aim of the study is to validate the IPAQ-SF questionnaire in a population of lower limb amputee patients. The questionnaire is administered twice to each patient, once during the consultation and again when they return home. Patients also undergo a 6-minute walk test.
When the prosthetic socket of a Veteran with a lower limb amputation no longer fits or is damaged beyond repair, a new prosthetic socket is warranted. The provision of a new socket requires multiple clinical visits which can place a high travel burden and potential pandemic exposure stress on Veterans who live in rural communities far from VA Medical Centers or alternative prosthetic clinics. This research seeks to determine if one of the in-person visits traditionally needed to obtain a well-fitting prosthesis can be performed remotely with the assistance of a helper. The investigators seek to discover if an untrained individual (a helper) can wield inexpensive, easy to use, digital technology to capture the shape of a residual limb to see if it can be used to fabricate a prosthetic socket that fits at least as well as one fabricated by a prosthetist using traditional, hand casting methods in the clinic. The expected result of this research is an evidence-based prosthetic fabrication process that reduces Veteran travel burden while providing a prosthesis that fits at least as well as the current standard-of-care. The upshot is a clear improvement in prosthetic provision for Veterans, particularly for those who live in rural communities. To make this determination, the investigators will perform a between-subject experiment with two specific aims. To determine differences in goodness of fit between the two study sockets, the investigators will use both patient reported outcomes, and measurements of the pressure applied to the distal end of the residual limb. Specific Aim 1: Determine if patient reported outcomes, by subjects wearing a prosthetic socket whose shape was captured with study helper assistance, are at least as good as those reported by subjects wearing a socket whose shape was captured by a prosthetist. The investigators propose to recruit Veterans with a below knee amputation and their study helpers to participate in a human subject experiment. Participants will be randomly assigned and fit with either a prosthesis made with study helper assistance and digital methods, or one made wholly by a prosthetist using traditional methods. Patient reported outcome metrics will be collected while the subject is still wearing their as-prescribed socket at the beginning of the study (baseline), and again after wearing the study prosthesis for two weeks. Specific Aim 2: Determine if distal end residual limb pressure, measured from a group of individuals fit with a prosthetic socket whose shape was captured with study helper assistance using digital methods, are no worse than those measured from a group of individuals fit with a prosthetic socket whose shape was captured by a prosthetist using traditional methods. Concurrent with the human subject procedures briefly described above, the investigators propose to fabricate duplicates (copies) of the two prosthetic sockets used by each subject in Specific Aim 1. A novel sensor will be embedded in these duplicate sockets which can measure the pressure applied to the distal end of the residual limb. Measurements of distal end residual limb pressure while standing and walking for both the as-prescribed and study sockets will be collected at the beginning of the study (baseline), and again after two weeks. The data from the investigators' experiments will be used to determine if residual limb shape capture by a helper using digital technologies can be used to make prosthetic sockets that fit at least as well as those made by a prosthetist using traditional, hand casting techniques. One third of all Veterans live in rural communities far from VA Medical Centers. When Veterans with a lower limb amputation need a new prosthetic socket, attending in-person clinical visits can be a challenge. If the hypotheses are supported, this research will provide evidence to support the use of digital technology as part of clinical practice, enabling a remote, study helper enabled alternative to one of the in-person clinical visits needed to fabricate a well-fitting prosthesis.
The currently accepted standard for rehabilitation and mobility following amputation is a socket-mounted prosthesis. Osseointegration is an alternative method that has gradually gained greater acceptance in the last 30 years. It is defined as a procedure in which a metal implant is directly anchored to the residual bone, attached to a prosthetic limb using a transcutaneous connector. The advantages of osseointegrated prostheses over conventional socket prostheses include stable fixation, significant increases in walking ability, range of motion and control of the prosthesis, and health-related quality of life. Moreover, bodyweight distribution results more similar to physiological conditions. No formal consensus exists for osseointegration surgery. However, based on the positive clinical experience, surgeons currently indicate this surgery for those patients who show poor tolerance of socket prostheses. The present study investigates neuro-physiologic and mechanical parameters of walking and balance in patients with lower limb amputation and osseointegrated prostheses and in matched patients with traditional socket prostheses to highlight strengths and weaknesses of the alternative technique with respect to the present standard of care. The primary endpoint is the investigation of the neurologic and mechanic adaptation in terms of a) kinematic and dynamic segmental analysis of walking and transfer of the body center of mass during walking; b) capacity to retain balance in response to different conditions of oscillation, tilt, and translation of a posturographic platform. The secondary endpoint is investigating of adaptation to walking on a split-belt treadmill mounted on force sensors with the belts running at different velocities. We hypothesize that: - the deficit in joint power of the prosthetic limb is associated with a phenomenon of "learned non-use" both in balance and during gait. This behavior looks automatic and unconscious. It consists of the under recruitment of the impaired side as a form of unconscious protection, which is adopted when the contralateral side may be exploited to carry out the function; - the joint power provided by the prosthetic limb may increase both by increasing treadmill velocity and by walking in split-belt modality with the prosthetic limb on the faster belt; - an "after-effect" will be evidenced after the split-belt walking test when the two belts will return to the same velocity; patients with osseointegrated prostheses and patients with socket prostheses may show different behaviors in the adaptation to split-belt walking and the following post-adaptation, as a result of the residual proprioception of the amputated limb. Results from the present study will allow: - the identification of the possible advantages in walking and balance symmetry in patients with osseointegrated prostheses with respect to patients with socket prostheses; - the estimate of the sample size for future experimental protocols and new rehabilitative programs.
The purpose of this study is to compare the risk of serious adverse events associated with the use of sodium-glucose cotransporter 2 (SGLT2) inhibitors in comparison with the use of dipeptidyl peptidase-4 (DPP-4) inhibitors among patients with type 2 diabetes. More specifically, the investigators will assess the risk of severe urinary tract infection (urosepsis), diabetic ketoacidosis and lower extremity amputation. The investigators hypothesize that the use of SGLT2 inhibitors will be associated with an increased risk of serious adverse events in comparison with the use of DPP-4 inhibitors. The investigators will carry out separate population-based cohort studies using health care databases in seven Canadian provinces and the United Kingdom. Separate study cohorts will be created for each of the three safety outcomes. The study cohorts will be defined by the initiation of a SGLT2 inhibitor or a DPP-4 inhibitor after SGLT2 inhibitors entered the market. Patients will be followed up until the occurrence of an adverse event. The results from the separate sites will be combined by meta-analysis to provide an overall assessment of the risk of serious adverse events in users of SGLT2 inhibitors in comparison to users of DPP-4 inhibitors.
Individuals with lower limb amputation often complain about uncomfortable residual limb skin temperatures and the accumulation of sweat inside their prostheses. It doesn't take long before the presence of sweat on the residual limb leads to a lack of confidence in the security of their prosthetic suspension. Some circumstances allow the wearer to doff the prosthesis before it falls off, wipe it and the residual limb dry, and then don it again. Another option is to simply reduce the intensity of activities before sweat becomes a problem. However, the Warfighter amputee may not be afforded such accommodations. For these service personnel, inadequate moisture management can significantly limit or inhibit their mobility. The objective of the proposed research is to provide lower limb amputees who work in demanding environments with a prosthesis that remains secure despite profuse residual limb sweating without compromising residual limb health and comfort. The aim of this research is to compare three different, lower limb prosthetic suspension systems and identify which is most effective at maintaining a secure adherence when worn in conditions that result in profuse sweating. The investigators also aim to compare how the three study prostheses effect residual limb skin health and comfort when participants pursue their usual activities in the home, work, and community environments. To achieve these aims, the investigators will to recruit 25 below-knee amputees. Each subject will be asked to be asked to wear: (1) their as-prescribed prosthesis, (2) a prosthesis with a perforated elastomeric liner that allows sweat to flow away from the skin, and (3) a prosthesis that has a battery and body-weight activated pump to flow air between the prosthesis and the residual limb skin, allowing expulsion of any accumulated sweat. Subjects will wear each of these prostheses in the home, work, and community environments for two weeks, after which the investigators will measure their residual limb health and comfort. Subjects will then walk on a treadmill in a room whose climate will be set to Middle East-like conditions: 35 °C (95 °F) and 50% relative humidity. After 30 minutes, the investigators will measure any slippage of their prosthesis relative to their limb and how much sweat is expelled. The investigators hypothesize there will be differences in the amount of slippage, residual limb health, and comfort between the three prostheses.
The purpose of the study is to obtain performance measurements and participant feedback about use of an investigational prosthetic foot compared to the participant's usual prosthetic foot. To accomplish this, the study will use a combination of laboratory motion analysis, functional tests, and community mobility trials where participants complete questionnaires and interviews about use of an investigational prosthetic foot compared to the participant's usual prosthetic foot. Individuals with amputations that participate in the (optional) motion analysis sub-study at the University of Washington will complete forward walking, side-step, and across river rock with usual foot (session 1), and also with the investigational foot locked and unlocked (session 2) after an accommodation period of between 1-4 weeks. The participants will rate their experiences using socket comfort score and the socket pressure score. Control participants recruited at the University of Washington to provide information about performance for people without amputation will go through the consenting process, then will be asked to complete forward walking, Figure-of-8 Walk Test, Narrowing Beam Walking Test, side-step, and walking across river rock surface. These tests will be conducted at a single session.
The LEAP protocol is a prospective cohort study of dysvascular patients designed to determine whether implementation of a multi-disciplinary lower extremity amputation protocol in the peri-operative period can shorten post-operative length of stay in patients undergoing trans-tibial or trans-femoral amputations. A consecutive sample of patients diagnosed with peripheral vascular disease and/or diabetes requiring major lower extremity amputation will be enrolled in the study and compared to retrospective controls.
When prescribing a prosthetic foot, clinicians face a dizzying array of choices as more than 200 different prosthetic feet are available. While these conventional prosthetic feet primarily function in the sagittal plane, the intact foot and ankle comprise a complex set of joints that allow rotation in multiple planes of motion. Some of these motions are coupled, meaning rotation in one plane induces motion in another. One such coupling is between the sagittal and transverse planes. For every step, plantar- and dorsi-flexion motion in the sagittal plane is coupled with external and internal rotation of the shank relative to the foot in the transverse plane. There is no prosthetic foot available for prescription that mimics this natural coupling. To investigate the need for this coupling, the investigators have built a torsionally adaptive prosthesis where the coupling ratio between the transverse- and sagittal-planes can be independently controlled with a motor. This research has one specific aim: to identify the optimal coupling ratio between transverse- and sagittal-plane motions using a novel, torsionally adaptive prosthesis for individuals with lower limb amputation. The investigators will conduct a human subject experiment wearing the motor-driven and computer controlled torsionally adaptive prosthesis. Individuals with lower limb amputation will be asked to walk in a straight line and in both directions around a circle while the coupling ratio between transverse- and sagittal-plane motions is varied between trials. Participants will be blinded to the coupling ratio. The investigators hypothesize that: (1) a coupling ratio exists that minimizes undesirable transverse-plane socket torque and (2) there will be a coupling ratio that individuals with lower limb amputation prefer.
The purpose of the study is to evaluate the use of the SPY Elite System to assess real-time tissue perfusion of lower extremity amputation sites and to develop parameters to predict healing of amputations at the time of surgery. This is a pilot study to see if the Spy Elite System is capable of recording accurate measurements on amputation sites to allow some correlation to healing. If this study shows promise for the device, the investigators would plan a larger study in which the data would be assessed in the operating room at time of acquisition and revision performed if needed based on the findings.