Clinical Research Directory

Improving Prosthetic Arms for Amputee: A Better Fit and More Functionality

This research and development will improve upon and investigate the potential validity of an innovative new transradial socket and harness design (the KSH system) that offers an alternative to standard hard sockets and rubber liners with a hybrid polymer and textile-based design derived from advanced athletic shoe technology. The project consists of designing, custom fitting and evaluating the function and comfort of the this new novel system. The study will take place in 3 phases; Phase 1, five experienced Veterans with transradial arm amputations will be recruited to provide guidance and to assist with the design and development. Experienced end-user Veterans and Clinical staff will work together to assist with design, develop the fitting process and working with engineers on the design of a completely digital fitting device for measuring the residual limb and locating bony prominences of the limb to inform the socket design. Phase 2, testing and assessment, the design and process validation will take place with the five Veteran upper transradial arm amputees Phase 3, an additional 20 Veterans with transradial arm amputations will be recruited and fit with the KSH system and undergo a series of evaluative tests. Veterans will perform a series of static and dynamic tasks to evaluate function, comfort and load bearing failure. The primary goal of this study is to improve upon the current preliminary prototype and to test it with a broader population of potential users to help advance the engineering and design, and to learn the potential to fit a range of Veterans with transradial amputations.

Cryoanalgesia to Treat Phantom Limb Pain Following Above-Knee Amputation

When a limb is severed, pain perceived in the part of the body that no longer exists often develops and is called "phantom limb" pain. Unfortunately, phantom pain goes away in only 16% of afflicted individuals, and there is currently no reliable definitive treatment. The exact reason that phantom limb pain occurs is unclear, but when a nerve is cut-as happens with an amputation-changes occur in the brain and spinal cord that actually increase with worsening phantom pain. These abnormal changes may often be corrected by putting local anesthetic-called a "nerve block"-on the injured nerve, effectively keeping any "bad signals" from reaching the brain with a simultaneous resolution of the phantom limb pain. However, when the nerve block resolves after a few hours, the phantom pain returns. But, this demonstrates that the brain abnormalities-and phantom pain-that occur with an amputation are not necessarily fixed, and may be dependent upon the "bad" signals being sent from the injured nerve(s), suggesting that a very long peripheral nerve block-lasting many months rather than hours-may permanently reverse the abnormal changes in the brain, and provide definitive relief from phantom pain. A prolonged nerve block lasting a few months may be provided by freezing the nerve using a process called "cryoneurolysis". The ultimate objective of the proposed research study is to determine if cryoanalgesia is an effective treatment for intractable post-amputation phantom limb pain. The proposed pilot study will include subjects with an existing above-knee amputation who experience intractable daily phantom limb pain. A single ultrasound-guided treatment of cryoneurolysis (or sham block-determined randomly like a flip of a coin) will be applied to the major nerves of the thigh. Although not required, each subject may return 4-6 months later for the alternative treatment (if the first treatment is sham, then the second treatment would be cryoneurolysis) so that all participants have the option of receiving the active treatment. Subjects will be followed for a total of 12 months with data collected by telephone.

Early Postoperative Pain Following a Limb Amputation

The primary aim of this study is to characterize the trajectory of pain and functional recovery in the first post-operative period following a limb amputation. Secondarily, this study aims to conduct an exploratory analysis to evaluate potential associations between clinical, demographical and therapeutical variables and primary outcomes including pain intensity, pain control and functional recovery.

Prevention of PostAmputation Pain With Targeted Muscle Reinnervation

The goal of this study is to compare postamputation pain (phantom limb pain and residual limb pain) one year postoperatively in patients who received a lower extremity amputation (LEA) with standard nerve handling (neurectomy) versus those who received Targeted Muscle Reinnervation (TMR). Patients between 18 and 75 years old, scheduled for an LEA (transfemoral to transtibial) as a primary or secondary sequela of vascular disease, are randomized into standard neurectomy or TMR. TMR is a frequently studied surgical technique and prevents neuroma formation by rerouting a cut mixed nerve end to a functional motor nerve. The investigators hypothesize that TMR during amputation surgery will significant improve PostAmputation Pain (PAP), quality of life, participation in family life and society, and reduction of health-related costs. Participants will be asked to complete multiple online questionnaires postoperatively regarding these outcomes at five evaluation moments (at 2 weeks, and at 3, 6, 9, and 12 months).

Comparison Between Digital Nerve Microanastomosis and Traction Neurectomy in Post-Digital Amputation Pain

The goal of this prospective observational study is to assess the post-operative pain in adults with digital amputation following two different surgical interventions: microanastomosis of digital nerves or traction neurectomy. The main questions it aims to answer are: * Which surgical intervention results in less post-operative pain? * Which surgical intervention leads to fewer symptoms after six months? * Which surgical intervention is associated with fewest post-operative complications? Participants will complete a Visual Analog Scale (VAS) to assess the pain and the Disabilities of the Arm, Shoulder and Hand Questionnaire (DASH) to evaluate the disabilities. The researchers will assess post-operative complications during follow-up appointments.

Neuromusculoskeletal Interface for Bionic Arms

The overall objective of this proposal is to perform a first-in-human home trial of the Electronic Osseoanchored Prostheses for the Rehabilitation of Amputees (e-OPRA) implant system in individuals with transhumeral amputations who have had Targeted Muscle Reinnervation (TMR) surgery and use a pattern recognition-controlled myoelectric prosthesis. The purpose of the study is to capture preliminary safety and effectiveness information on the e-OPRA device when used with the prosthetic systems. The investigators expect that the e-OPRA implant system will be safe and provide clinically and statistically significant improvements in control and comfort. Specifically, the investigators hypothesize that the e-OPRA system will (1) allow for training of more functional prosthesis controllers, (2) provide more stable electromyographic (EMG) signals, reducing the need to recalibrate the prosthetic control system, and (3) be more comfortable, as it does not require a tethered arm-band to record surface EMG signals. Phase 1: Perform TMR and e-OPRA surgeries in 8 persons with transhumeral amputations. Phase 2: Perform a randomized cross-over study to compare the OPRA and e-OPRA system (without sensory feedback) in 8 transhumeral amputees who have received TMR. Phase 3: Perform a randomized cross-over study to compare the e-OPRA system with and without sensory feedback in 8 transhumeral amputees who have received TMR.

Analyzing Anesthetic Techniques in Diabetic Foot Amputation

Diabetic Foot Amputations: A Comprehensive Review of Anesthetic Procedures and Outcomes Introduction: Diabetic foot is a severe complication of diabetes, often resulting in ulceration, osteomyelitis, and gangrene. Amputation or surgical debridement is the standard treatment for advanced cases. The study aims to evaluate the outcomes of different anesthetic techniques in diabetic foot amputation, specifically comparing peripheral nerve block (PNB) and general anesthesia. Objective: To assess the impact of anesthetic procedures on outcomes in diabetic foot amputation cases using inpatient data. The hypothesis is that PNB will result in fewer postoperative complications than general anesthesia-primary outcome: 30-day mortality; secondary outcomes: composite morbidity and hospital discharge duration. Materials and Methods: This retrospective chart review will analyze medical records of patients with diabetic foot at Ankara Bilkent City Hospital from 2021 to 2023. Inclusion criteria: patients who underwent toe, ankle, or foot amputations. Exclusion criteria: patients under 18, amputations for non-diabetic reasons, and insufficient medical data. Data will include patient demographics, preoperative medications, comorbidities, and surgical details. Major complications, secondary outcomes, and mortality will be primary measures. Statistical Analysis: Descriptive statistics will summarize patient characteristics. Chi-square and Student t-tests will analyze associations between anesthesia type and postoperative outcomes. Kaplan-Meier survival analysis will compare hospital stay durations. Logistic regression will adjust for confounders and assess the impact of anesthetics on complications. Results will be significant at p \< 0.05.