Detecting Arch Instability in Charcot Neuropathy

AbstractCharcot neuropathy (CN) is a serious complication resulting from poorly controlled diabetes and peripheral neuropathy that leads to the collapse, and ultimately the breakdown, of the midfoot. Charcot occurs in approximately 0.08% of the general diabetic population, however the prevalence increases to 13% in high-risk diabetic patients [1,2] and even 35% in patients with polyneuropathy in industrialized countries [3]. In terms of treating CN patients, Chantelau et al. [7] described the “perils of procrastination” and showed the effects of early versus delayed detection of arch instability and collapse.The Cleveland State University (CSU) team recently identified an early detection concept for arch instability [8] using a platform system for plantar shear and pressure measurements produced by Innovative Scientific Solutions Inc. (ISSI). The study developed a metric (Sflatten) to quantify arch instability that compared posterior shear under the heel with the anterior shear under the first metatarsal head. Sflatten was significantly higher in neuropathic diabetics than in controls. Unfortunately, the platform system limited the evaluation to barefoot plantar contact patterns and a limited number of steps. Here we propose the next step in developing a tool for detecting and monitoring arch instability, specifically, an in-shoe system that measures plantar pressure and shear in normal footwear over multiple gait cycles. We believe that an in-shoe system will also facilitate clinical deployment.Phase I will combine CSU’s arch collapse detection algorithms with ISSI’s new in-shoe sensor technology. It will include benchtop calibration and validation of the in-shoe system and comprehensive gait testing with a cohort of control subjects with varying arch indices. If successful, Phase II will evaluate the system’s performance with diabetic and Charcot patients and develop risk thresholds. The overall objective is to lay the groundwork for commercializing a product that not only enables early diagnosis and monitoring of “Charcot foot”, but also addresses the broad need to assess risk factors for skin breakdown under the feet of diabetic patients.Project NarrativeIndividuals with diabetes are particularly susceptible to a spectrum of osteopathies and arthropathies in the foot and ankle. One such complication is the destructive Charcot process that often leaves the patient with a non-functional, deformed foot that has no propulsive value and a high risk of ulceration. The proposed program will demonstrate the feasibility of an in- shoe shear measurement system that detects early signs of arch collapse to alert physicians to incipient Charcot’s Neuroarthropathy.