Characterizing Cutting Methods for Collagen Membranes Used in Orthopedic Surgery

Abstract

Cartilage is a grand challenge in orthopedics because defects are common, it is not self-healing, and there is no equal or better replacement. A new approach called Matrix Autologous Cartilage Implantation (MACI) has gained popularity for treating knee cartilage defects. MACI requires extracting cells from a patient, growing them on a collagen membrane, removing defective cartilage from the patient’s knee, and inserting the cell-coated membrane into the debrided defect area. The surgery requires cutting the collagen membrane to match the shape of the debrided cartilage. However, a lack of effective cutting methods has led to surgeons unnecessarily remove healthy cartilage to create an easier shape to match the membrane to, which decreases patient outcomes. This thesis will investigate several cutting methods to be used on cell-coated collagen membranes in order to maximize cut customization. Blade cutting and laser cutting are the main methods considered, and key metrics include minimum radius of curvature and cut accuracy. Additionally, this thesis seeks a geometric relation between the radius of a rotary blade and the minimum radius of curvature which it can cut. Scanning Electron Microscopy and a cytotoxicity test will be used to validate the biology of the membrane and cells.