Pre-clinical feasibility study of a novel implant for treatment of a cartilage defect in the medial femoral condyle

+Waldorff, E I; Cole, J H; Roessler, B J; Zachos, T A; Miller, B S; Gordon, J; Johnson, P; Johannaber, K; Morris, M D; Goldstein, S A +Department of Orthopaedic Surgery, University of Michigan, Ann Arbor, MI; Department of Chemistry, University of Michigan, Ann Arbor, MI Department of Internal Medicine, Rheumatology, University of Michigan, Ann Arbor, MI Department of Small Animal Clinical Sciences, Michigan State University, East Lansing, MI; Synvasive Technology Inc., El Dorado Hills, CA [email protected] INTRODUCTION: The advent of modern cartilage repair techniques is expanding the development of restorative concepts. A challenging aspect of cartilage restoration continues to be the need to reliably restore a continuous articular surface capable of weight bearing functions. Based on reconstructive device concepts, previous investigations have explored the use of several different materials ranging from alloys [1,2] to polymer composites [3]. Current research into this device concept continues to demonstrate potential benefits [4], but has potential limitations relating to biologic fixation. Based on previous investigations into porous-coated implant topology [5], a novel non-resorbable articular matrix ceramic was developed to test the feasibility of replacing a region of degenerated or damaged cartilage in a large pivotal preclinical model. The device produced from this ceramic is monolithic in form with a highly polished submicron articular surface and interconnected porous structure exhibiting approximately 60% porosity. Two primary hypotheses were tested: (1) The use of a ceramic articulation surface, as part of a regional replacement of cartilage, has no damaging effects on natural articular cartilage. (2) A composite ceramic implant with a macroscopically porous topology and conical geometry can provide immediate fixation and promote secure long-term bone adaptation.