Several factors in the design of a prosthesis, including socket fit, suspension, alignment, and component selection, present challenges for clinicians. Clinicians are also commonly evaluated and incentivized based on delivery turnaround times and their ability to navigate reimbursement limitations and optimize reimbursement with component selection—all factors that contribute to a positive bottom line for the business.
However, the real measure of success is whether a prosthesis restores function, improves mobility and outcomes, and encourages patients to continue participating in the activities they love, giving them confidence to return to your office for future prosthetic care. This is why extended clinical trials deserve more attention in daily practice, and a well-fitting socket is an integral part to the success of any prosthesis design.
An extended clinical trial goes beyond a period of use and wear in the clinic, on stable ground, in a controlled environment. It should be a deliberate, iterative clinical approach that allows the prosthetist and the patient to work as a team to refine the socket fit while considering daily mobility and environments encountered, evaluate and optimize component selection, and perform comparative analysis, resulting in enhanced shared decision-making. This process allows for continued refinement to optimize outcomes prior to fabrication of the definitive prosthesis. The extra time and attention to detail can be the difference between a prosthesis that exists as a tool versus one that is truly integrated into a patient’s life.
Extended Clinical Trials
In clinical practice, an extended clinical trial may involve several iterations of test socket design, comparative analysis of alternative components, and refinement of socket fit and alignment. The process provides intentional opportunities for patients to provide feedback and input during real-world use, and clinicians can evaluate how patients perform over time. If the practice does not currently use extended clinical trials, it will result in more frequent appointments initially but has the potential to reduce visits for required adjustments and follow-ups after delivery. Additionally, patients can evaluate their prostheses and components in their daily routines. If they encounter challenges such as navigating uneven terrain, participating in activities such as golfing or hiking, or they experience skin irritation, decisions to improve the socket fit and component selection can be made before any device has been provided.
In the office, patients walk for shorter distances in a very controlled environment. It is challenging to simulate full-time daily use and variable factors encountered in daily life. Many clinics attempt to adapt settings to evaluate the prosthetic fit and alignment using treadmills to simulate long distance walking, rely on outside terrain to further evaluate the fit, and have stairs in the clinic. This still only offers a condensed time frame and opportunity to evaluate the design of the prosthesis. Extended clinical trials provide a structured process to catch and address issues early, while there is still maximum adjustability in a diagnostic socket and component selection.
Shared Decision-Making and Comparative Analysis
As clinicians, we aim to be experts in prosthetics, narrowing design options for what may be best suited for patients based on their goals and activities; however, through shared decision-making and comparative analysis of prosthetic components, we can support patients in being experts on their prostheses.
Shared decision-making is a tool focused on a collaborative approach used to intentionally include patients in the selection process for their prostheses.1 This includes discussions about activity, goal setting, and concerns to create a space of open dialogue with patients. Comparative analysis of prosthetic components can further enhance the collaborative approach through shared decision-making.
Previous research around shared decision-making has shown that clinicians tend to focus more on the factors of prosthesis design, including suspension, socket style, or component selection, while patients tend to focus more on personal goals and integration into daily life.2,3 Extended clinical trials can be beneficial to blend both sets of priorities together. For example, a patient may want to golf, live a fairly active life, and keep up with grandkids. A prosthetist may consider a foot component that includes a torsion adapter to assist with the rotational motion through a golf swing. However, evaluation of different foot components allows a patient to experience the foot component in daily mobility demands and while golfing. Some feet may offer more stability and feel stiffer, while another foot component can be “bouncier” while still integrating a torsion adapter. As they trial different foot components, patients will learn about the differences in prosthetic foot responsiveness and about his or her personal preferences. Even with similar goals and activity demands, each patient may have a different preference. As the clinician, it can be helpful to narrow options down within the constraints of coverage, medical necessity, and clinical relevance; however, patient preference and feedback should be considered in the component selection.
Similarly, for patients with a transfemoral amputation, considering options for a microprocessor knee may require evaluation of different options. Some patients may respond better with the knee’s stance-to-swing behavior over another component, allowing for increased consistency with each step and improved patient confidence. One patient may feel more comfortable with a prosthetic knee that responds quickly and dynamically, while another patient may do better with a knee that feels more stable and predictable. Sometimes the problem is not that the patient is “cheating” the knee; it is that the knee’s response does not match how that patient moves naturally. Overall, trialing components in the clinic and in daily life allows patients to determine their preference and pick up on nuances in functionality that they cannot evaluate based on description alone.
Liability Perspective and Business Costs
Prior to my education, I volunteered for a summer at Bremer Prosthetics where extended clinical trials were commonplace for patients. Patients were well educated about the limitation of the diagnostic socket as it is less durable than a laminated socket, the importance of watching for any signs of stress to the diagnostic socket, and encouraged to call the office if there were any concerning noises. I was surprised during my education that the first reaction was that this is not common practice and could be viewed as a liability.
It is worth reviewing your company insurance policy to confirm that product liability coverage would provide protection for any potential incidents. Additionally, best practices would include creating an internal protocol for extended clinical trials, standard patient education to encourage patient safety through the extended trial, and documented standard procedures for reinforcing the diagnostic socket.
Modifying current practices to include extended clinical trials as part of a standard evaluation and fitting process will lead to longer turnaround times before definitive prosthesis delivery but should be viewed as an investment in long-term outcomes. Limited research suggests that use of diagnostic sockets, where the time is invested on the front-end of the fabrication process, reduce frequency of follow-up appointments.4 This requires reframing how we think of efficiency, investing in refining the socket fit, component selection, and patient satisfaction, and if a socket shape and alignment can be used later to duplicate a fit and further reduce the timeline from evaluation to delivery of future prosthetic sockets.
Current and Future Research
There is limited literature on the use of diagnostic sockets in clinical care and patient outcomes, and an initial review yielded no literature discussing extended clinical trials in relation to patient outcomes. One article compared patient outcomes between two groups: One group received a diagnostic socket and one group did not.4 The groups were homogenous with no statistically significant differences in demographics including weight, height, body mass index, and side of amputation. The article suggests that refinement of prosthesis design with the use of a test socket has a significant impact on patient functionality, pain, and patient satisfaction.
Future research is needed to further explore the value added from refining prosthesis design through the use of diagnostic sockets, comparative analysis of components, and extended clinical trials. This research is just as pertinent to upper-limb prosthetic care as lower-limb prosthetic care. The process of including extended clinical trials as a standard of care reflects a model of patient care prioritizing function, safety, patient confidence, and long-term outcomes.
The limited research can suggest the benefits for the use of test sockets but does not evaluate differences between in-clinic trials and extended clinical trials. As we start to define the value added from diagnostic sockets, we can advocate for our profession and the value of the care provided. As clinicians, we go beyond providing devices as we educate the patient, assess, problem-solve, and advocate with the patient.
Conclusion
Extended clinical trials should be considered a routine part of patient care to optimize long-term outcomes. It affords clinicians the opportunity to refine the fit, function, and design of the prosthesis with the patient rather than for the patient. Utilizing extended clinical trials supports shared decision-making, may lead to improved outcomes, and challenges our profession to consider what efficiency and success truly look like.
Abbey Gilhooly, MBA, MPO, CPO, FAAOP, is a member of the Academy’s Lower Limb Prosthetics Society and a clinician at Bremer Prosthetic Design, Michigan.
Academy Society Spotlight is a presentation of clinical content by the Scientific Societies of the Academy in partnership with The O&P EDGE.
References
- Shay, L. A., and J. E. Lafata JE. 2015. Where is the evidence? A systematic review of shared decision making and patient outcomes. Medical Decision Making 35(1):114-31.
- Anderson, C. B., A. J. Kittelson, and S. R. Wurdeman, et. al. 2023. Understanding decision-making in prosthetic rehabilitation by prosthetists and people with lower limb amputation: A qualitative study. Disability and Rehabilitation 45(4):723-32.
- Anderson, C. B., S. Fatone, and M. M. Mañago, et. al. 2023. Improving shared decision-making for prosthetic care: A qualitative needs assessment of prosthetists and new lower-limb prosthesis users. Prosthetics and Orthotics International 47(1):26-42.
- Aydın, A., and S. Çağlar Okur. 2018. Effects of test socket on pain, prosthesis satisfaction, and functionality in patients with transfemoral and transtibial amputations. Medical Science Monitor 24:4031-7.
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