Abstract
Medical innovation is often understood as a matter of efficacy, but in practice, it also depends on whether a device can be implemented, adopted, and sustained in the real world. Knee osteoarthritis, which affects around 365 million people worldwide, presents exactly this kind of challenge. My capstone project focuses on the development and evaluation of a non-surgical knee distracting brace for osteoarthritis, a disease that is increasingly prevalent and difficult to treat effectively without total knee replacement. This research was undertaken to address the treatment gap between conservative therapies and surgical knee joint distraction by exploring whether an orthosis could provide measurable joint distraction in a non-invasive manner. My STS paper examines how insurance and reimbursement infrastructures shape medical device innovation beyond clinical efficacy alone, and I undertook this research to better understand how coverage determinations, billing codes, and payment systems influence which devices become viable. These two projects are connected because both investigate constraints on innovation in medical devices. While the capstone project examines the technical development of a device intended to improve treatment for knee osteoarthritis, the STS project examines the administrative and infrastructural conditions that determine whether such a device could become a practical treatment option.
My capstone contributes toward a non-invasive alternative to knee joint distraction surgery, which has shown promising clinical outcomes but remains limited by surgical burden, infection risk, and low patient acceptance. Methods included determining clinical requirements, refining an existing prototype, assembling and validating an electronic distraction device, and evaluating performance through force testing and X-ray imaging of joint space width. The project sought to determine whether the device could produce meaningful and quantifiable distraction while moving toward a design that could eventually be clinically tested with greater patient comfort and accessibility.
Testing confirmed that the orthosis effectively provides limited, non-invasive distraction, with a maximum of 1.25 mm on the lateral side and a decrease of about 0.5 mm on the medial side. Despite not fully reaching x-fix distraction levels, this is a successful proof of concept. Results showed a non-linear force-distraction relationship, with variability due to brace slippage dependent on fit and force applied. Overall, this is particularly successful due to the non-invasive nature, fit issues with specific cadavers, and the non-arthritic nature of the cadaver knee, which would have less distraction than an arthritic joint due to cartilage degradation. Clinical trials will be needed to assess fit, comfort, slippage, and regeneration over time.
My STS paper asks how reimbursement infrastructures, specifically Medicare coverage, coding, and payment systems, make billability a foundational design constraint. This is significant because it shifts attention from FDA clearance alone toward the administrative systems that govern adoption and patient access. Using qualitative case-study methodology grounded in document analysis and Actor-Network Theory, the research draws on CMS coverage determinations, fee schedules, and CPT code descriptors to outline how reimbursement criteria become embedded in device design and clinical workflows.
The evidence shows reimbursement systems do not simply follow innovation but actively shape it. Across cases involving CPT code transitions, coverage determinations, remote patient monitoring requirements, and orthotic documentation rules, billability functions as an obligatory passage point, reorganizing what counts as evidence and which institutions can provide access. The paper concludes that in Medicare-linked markets, billability can become a stronger constraint than clinical effectiveness alone, operating as a hidden specification that structures clinical practice and distributes access unevenly across providers and patients.
