Improving Treatment for Patellar Instability to Reduce Recurrence and Cartilage Degradation
Abstract
The proposed study addresses two Fiscal Year 2019 Peer Reviewed Medical Research Program Topic Areas: Musculoskeletal Disorders and Post-Traumatic Osteoarthritis. An unstable, or dislocating, kneecap (patella) is a musculoskeletal disorder that causes significant functional impairment to young, active patients. For a right knee, the kneecap typically dislocates from the groove on the thigh bone (femur) toward the right, with the opposite direction for a left knee. A sudden, forceful dislocation of the kneecap is estimated to account for more than 3% of all knee injuries. The first time a dislocation occurs, a patient is typically treated with physical therapy rather than surgery, although more than 30% of patients typically have a second dislocation. Dislocation and relocation of the kneecap traumatically loads cartilage on the kneecap and within the groove, and these instability episodes are considered a contributor to patellofemoral osteoarthritis. The risk of post-traumatic osteoarthritis increases with multiple dislocation episodes. Multiple dislocation episodes are commonly addressed with a surgical procedure. The most common uses a graft made from a tendon to secure the kneecap to the femur. More complex surgical options are commonly employed when the anatomy is highly abnormal. These options include cutting the bone, which is associated with more serious complications. The investigators believe that selective early surgical intervention for patellar instability will improve both short-term and long-term function of the knee. The investigators propose to characterize cartilage degradation due to delaying surgical intervention until after multiple instability episodes, identify patients likely to progress to multiple instability episodes based on knee anatomy and alignment of the bones, and establish the anatomical parameters for which a graft can successfully restore patellar stability. For the first aim of the study, magnetic resonance imaging (MRI) will be used to characterize cartilage degradation for a group of patients being treated for an initial dislocation, multiple dislocations, and a group with healthy knees. The MRI scan can evaluate properties of cartilage based on the excitation of water molecules and protein structures within the cartilage. Fifteen patients will be recruited to each group. Patients with multiple instability episodes are expected to display more cartilage degradation than patients being treated for a single episode. For the second aim, a statistical shape model will be developed to represent the average shape of each knee scanned for Aim 1. A statistical shape model is created by averaging the surfaces of the bones of the knees for all subjects. The shape model also uses statistical methods to characterize the primary directions of variation among the knees. An imaging sequence that captures the knee in full extension with the quadriceps muscles activated will be implemented to include alignment of the bones within the shape model, so that the modes of variation can reflect anatomy and alignment. Features of bone shape and alignment associated with multiple instability episodes will be identified and weighted to identify the most relevant. For the third aim, a model for multibody dynamic simulation of knee function will be developed from the statistical shape model. A multibody dynamic model represents the structures of the knee as various components within computer software, such as rigid shapes for the bones, springs for ligaments, and applied forces for muscles. Mathematical representations of the interactions between the components create a system that can move to simulate knee function. The shape of the model will be deformable to represent any knee imaged based on the statistical shape model. For the knees with multiple episodes of instability and at highest risk for multiple episodes, the models will be used to simulate a jump landing that causes the kneeca
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Mar 10, 2021
- Source ID
- W81XWH2010040
Entities
People
- John Elias
Organizations
- Cleveland Clinic
- United States Army