Cartilage Deformation and Gait Biomechanics in Patients With and Without Chronic Ankle Instability

More than 75% of all ankle OA patients suffer from PTOA, which brings severe pain, reductions in physical activity, diminished mental health and limited physical function. Unlike idiopathic OA, PTOA has a well-defined precipitating insult from an acute ankle joint injury. Lateral ankle sprain (LAS) is the most common musculoskeletal injury among physical activity individuals. It has been estimated that an astounding 72% individuals who have an ankle injury go on to develop chronic ankle instability (CAI). This pathology is defined as recurrent ankle joint injuries, multiple episodes of “giving-way” and an increase in self-reported dysfunction. Recent work has demonstrated individuals with CAI have a loss of collagen fiber integrity, an early biomarker of ankle PTOA, within 10 years post injury. This progressive change in the integrity of the articular cartilage likely explains why CAI is a leading cause of ankle PTOA. Consistent evidence has demonstrated cartilage health is dependent upon its loading patterns. In patients with CAI, the sensorimotor and mechanical impairments manifest into abnormal biomechanics that alter the forces transmitted across the ankle. Yet, no investigation has examined the influence that abnormal loading patterns may have on cartilage health in patients with CAI. Illustrating the impact of altered loading patterns on cartilage health may assist in the development of more effective conservative treatments targeted at slowing the transition from CAI to PTOA. A new and novel technique to assess the integrity of the articular cartilage is quantifying the magnitude of cartilage deformation using ultrasonography (US). US can provide a quick and cost affective imaging modality that is often clinically accessible by athletic trainers. Briefly, the thickness of the articular cartilage is measured before and after a controlled amount of activity. The amount of cartilage deformation in response to a load is reliant on its compositional structure. Therefore, a change in the amount of deformation would suggest alterations in the compositional structure of the articular cartilage. Therefore, the overall goal of this project is to examine the influence ground reaction forces and gait biomechanics during walking have on cartilage health in patients with CAI. Our central hypothesis of this project is CAI individuals will have increased cartilage deformation which will be related with increased peak ground reaction forces and altered gait mechanics while walking.