Amputation Clinical Trials

Individuals with an above-knee lower limb amputation are known to walk more slowly, expend more energy, have a greater risk of falling, and have reduced quality of life compared to individuals without amputation and those with below knee amputation. One of the driving factors behind these deficits is the lack of active function provided by above-knee prostheses with prosthetic knees and ankles. While many prosthetic devices have been developed for functional restoration after major lower extremity amputation, there remains no stable interface to facilitate reliable, long-term volitional control of an advanced robotic limb capable moving multiple joints. Moreover, there is no existing interface that provides useful sensory feedback that in turn enhances the functional capabilities of the prosthesis. To achieve both greater signal specificity and long-term signal stability, we have developed a biologic interface known as the Regenerative Peripheral Nerve Interface (RPNI). An RPNI consists of a peripheral nerve that is implanted into a free muscle graft that would otherwise go unused in the residual limb. As the nerve grows, it reinnervates the free muscle graft which undergoes a predictable sequence of revascularization and regeneration. The main questions it aims to answer are: Can the amplitude, movement specificity and stability of sciatic nerve RPNI electromyography (EMG) signals be detected up to one year post RPNI surgery? Do RPNIs contain information to enable control of a physical motorized prosthetic leg with multiple degrees of freedom? Does stimulation of sciatic nerve RPNIs provides meaningful sensory feedback? Consenting participants with unilateral transfemoral amputation (TFA) will: Undergo RPNI surgery and electrode implantation in the residual limb. Attend regular follow-up visits following surgery to assess the health and signal strength of the RPNIs and their ability to use a prescribed prosthesis between 3- and 12-months following implantation. Undergo explantation of electrodes following the conclusion of data collection. Read Less

Objective/Hypotheses and Specific Aims: The first aim of this proposal is to determine the effects of commercial prosthetic feet of varying stiffness on stability and falls-related outcomes in Veterans with TTA. The second aim is to determine whether a PFE can be used to predict stability and balance-confidence outcomes with corresponding commercial prosthetic feet. The third and final aim is to determine whether a brief trial of commercial prosthetic feet can predict longer-term stability and balance-confidence outcomes in Veterans with TTA. Study Design: The investigators will use a participant blinded cross-over study with repeated measurements in Veterans and Service members with TTA. Up to 50 participants will be enrolled at each of the two study sites VA Puget Sound and VA Minneapolis. Participants will complete up to 6 visits. After an initial assessment visit, participants will be assigned to the 'high' or 'low' mobility group, and then during visit 2 they will be randomized to use the PFE in three foot modes or the three corresponding actual (commercially available) feet during walking tests on difference surfaces in the laboratory (cross-slopes, inclines, even, and uneven ground). During visit 3 participants will repeat the procedures in the other condition (e.g., PFE if visit 2 included actual feet testing). At the end of visit 3 participants will be fit with one of the actual feet and wear it at home and in the community for approximately one week. At visit 4 participants will be fit with the next actual foot and repeat the 1 week use window. The same process will be followed for the final foot at visit 5, and the study foot will be returned at visit 6. Read Less

Through this pilot prospective trial, we aim to obtain preliminary data investigating the effectiveness of perineural catheters and liposomal bupivacaine, both currently accepted as standard care at Maine Medical Center, for the management of post-limb amputation pain. We will use the data that we collect to inform the design of a larger, appropriately powered study. Read Less

The purpose of this study is to evaluate functional mobility, control, and user satisfaction from persons who have an amputation above the knee and have received osseo-integration (OI) and targeted muscle reinnervation (TMR) surgery, while walking with a powered knee and ankle prosthesis. Read Less

The overall goal of this project is to model human joint biomechanics over continuously-varying locomotion to enable adaptive control of powered above-knee prostheses. The central hypothesis of this project is that variable joint impedance can be parameterized by a continuous model based on measurable quantities called phase and task variables. This project will use machine learning to identify variable impedance functions from able-bodied data including joint perturbation responses across the phase/task space to bias the solution toward biological values. Read Less

The purpose of this study is to see if an investigational surgery that transfers tissue from a non-living donor to living individual will help restore greater function, appearance, and sensation to the hand and forearm areas of individuals who have suffered traumatic injury to the hand and forearm. This procedure is called a hand allotransplantation or "hand transplant". This study will also collect data on how patients do during and after having a hand transplant from a nonliving donor. Recovery and outcomes will be observed through clinical exams, x-rays, blood and tissue tests, and other associated evaluations at all follow up visits. Read Less

A national, multi-center registry of patients using lower-limb prosthesis, their profiles and devices, and their long-term follow-up and clinical outcomes. Read Less

The study will enroll 20 adults ages 18-75 with a transtibial amputation with mature residual limbs who are ambulatory prosthesis users. Participants will be randomized to either treatment with low dose volar fibroblast injections (n=10) or to vehicle control (n=10). Participants will undergo a biopsy to harvest volar skin for fibroblast expansion and tattooing to identify injection sites on the residual limb. Fibroblasts will be processed at the Hopkins Cellular Therapy Core Lab and volar cells primed for injection will be sent to participating centers for administration. Participants randomized to the treatment group will be treated with low-dose cells. Injections will be administered on at least 1 and up to three separate days over the course of one week. Participants randomized to the vehicle control group will receive injection of cryoprotectant. All participants will be followed at 2 weeks, 1, 2, and 3 months after the last injection. These visits will include a clinical evaluation for complications, non-invasive assessments of skin firmness and thickness, skin appearance, and patient-reported outcomes. After the final monitoring visit, individuals randomized to the vehicle control group will have the opportunity to receive the volar fibroblast injections and will be followed for an additional 3 months. The investigators hypothesize that (1) There will be no difference in the rate of serious adverse events among patients treated with volar fibroblast injections compared with patients treated with vehicle control, and (2) Patients treated with volar fibroblast injections will have firmer skin on the residual limb compared with patients tread with vehicle alone. Read Less

Lower limb amputees rely on their prosthetic to remain active and lead an independent life. In recent years, measuring residual muscle activity has been used to interpret a user's intent and thereby modulate prosthesis control. However, little knowledge is held on how residual muscle activity differs from non-amputated muscle. The research team will analyze and compare neuromuscular physiology in non-amputee individuals and amputees' non-amputated and residual muscles across functional tasks to better understand how amputees control their muscles. Such information will inform design of modern prosthesis controllers. Read Less

This study will involve the development of a novel approach to lower extremity residual limb surgical revision that offers the promise of augmenting volitional motor control, restore proprioception and reverse atrophy Read Less

The purpose of this study is to characterize the functional status and quality of life of patients undergoing Targeted Muscle Reinnervation (TMR) at time of major limb amputation (primary) or subsequent to major limb amputation (secondary). Participants can expect to be on study for about a year and will complete a short electronic survey and option phone interview. Read Less

The goal of this clinical investigation is to evaluate the clinical benefits of a ventilating suspension interface for individuals with transfemoral amputation. The main aim of the investigation will be to evaluate the clinical user-reported benefits to skin health from using a ventilating lower limb prosthetic suspension system and compare it to a non-ventilating suspension system. Read Less