Improving Physical Function and Patient-Reported Outcomes Through a Quantitatively Informed Socket Design Process
Abstract
Our research project is focused on improving the lives of people with above-knee limb loss. This proposal addresses two RESTORE focus areas: (1) objective support tools to enable providers to assess function and performance throughout treatment and predict long-term outcomes and (2) optimization of Warfighter performance following limb trauma or loss. People with above-knee limb loss experience chronic health challenges such as residual limb skin problems, low back pain, and osteoarthritis as side effects of using prostheses. These problems are exacerbated by poorly fit prosthetic sockets. The goal for prosthetists is to optimize the compromise between comfort and function. However, achieving this compromise is currently a long, iterative process that is based more on intuition and experience than on objective data. Subjective patient feedback and coarse outcome assessments guide the repeated modifications. The lack of objective data also limits our ability to predict long-term effects of prosthesis use, such as osteoarthritis from continuous overloading of the remaining leg. Prosthetists believe that limiting bone and skin motion within the socket will improve outcomes. However, there are no data to directly confirm that socket modifications can achieve these goals, and no data exist on how large of a reduction in bone and skin motion is needed to improve patient-reported outcomes. Therefore, the first Aim of our study is to measure in-socket mechanical factors, such as residual bone motion, skin strain, and pressure, and to find out whether they are related to physical function and comfort. If it is known which factors are most important, prosthetists can design the socket to limit bad motions and forces. Our first experiment will include 30 above-knee amputees who will walk on a treadmill wearing a series of sockets with slightly different volumes, brim heights, cross-sectional geometry, and stiffness compared to their current socket. Participants will complete a questionnaire on socket fit and comfort after wearing each socket. We will use specialized laboratory equipment to measure the in-socket mechanics for each socket design, including pressure within the socket, skin strain, and motion of the residual bone within the socket. We will also use common clinical tools to measure hip strength and range of motion, as well as video cameras to assess body movement during walking. Our second Aim is to test whether readily available clinical measurements are associated with the in-socket mechanics that are critical to patient comfort and functional outcomes. Measuring these in-socket mechanics directly is only possible using expensive research equipment. Exploring easier ways to estimate them is therefore important in order to apply our findings in clinical practice. We will investigate those measurements in our 30 amputees to develop a socket design optimization process that is based on clinical measurements rather than research grade data. For Aim 3, we will evaluate the new optimization process in an additional 15 above-knee amputees. We will compare time, cost, physical function, and patient-reported comfort and fit between our new optimization process and the current standard process. In summary, this study may help streamline the clinical prosthesis fitting and assessment processes and lead to improved comfort and performance for people with limb loss and decreased costs of the fitting process. Improving prosthetic provision for Service members and Veterans with limb loss is important to facilitate full rehabilitation, participation in society, and if so desired, return to active duty. The socket is the most important component of a leg prosthesis, above even high-tech foot/ankle and knee components. Improved socket design and fit will lead to better skin and tissue health, more efficient and comfortable prosthesis use, reduced pain and pain medication use, improved function and a healt
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Mar 10, 2021
- Source ID
- W81XWH2010914
Entities
People
- William Anderst
Organizations
- United States Army
- University of Pittsburgh