Additive Manufactured PEKK Implants for Small Bone Arthroplasty

ABSTRACT This Phase I STTR is designed to evaluate the feasibility of using the OsteoFabtechnology platform for joint arthroplastyArthroFabdevicesspecifically targeting replacement of the small carpal bones in the wrist and hemiarthroplastyOsteoFabtechnology is the combination of Oxford Performance Materialsandaposproprietary formulation of polyetherketoneketoneOXPEKKpolymerand additive manufacturingD printingThis STTR builds on an existing collaboration between DrJoseph Crisco and his team in the Department of Orthopaedics at the Warren Alpert Medical School of Brown University Rhode Island Hospitaland Oxford Performance MaterialsIncOPMa small business in South WindsorCT that is a world leader in bone replacements usingD additive manufacturingOPM currently markets FDA cleared patient specific devices for cranial and facial bone reconstructionOsteoFaband holds a clearance for a vertebral body replacement systemSpineFabworldwideHoweverthe performance of OPMandapos s OsteoFabdevices has not yet been investigated in synovial jointsnor in direct articulation with cartilageIn this project we will assess the feasibility of using the OsteoFabmanufacturing process to fabricate small articulating bone replacementsWe propose two independent specific aimsIn our first Aim we will use an established lunate resection model in the rabbit forepaw to evaluate cartilage healthlocal inflammationand bony changes afterweeks of OsteoFabarthroplastyThe ArthoFabLunate device will be fabricated and finished by OPMbased on an average lunate bone model generated using our well established computational and morphological modeling algorithmsThe average lunate will beD printed in laser sintered OXPEKKpolymer and the articular surfaces will be polishedwith features for soft tissue attachmentSixanimals will receive ArthoFabLunate devices and six will undergo lunate excision aloneIn our second Aimwe will assess in vitro cartilage wear response to cyclic loading in a hemiarthroplasty model via pendulum testingcyclesD models of the rabbit knee will be used to fabricate articulating ArthoFabTibia modelsExplanted fresh rabbit distal femur condyles will be flexed and extended against the ArthoFabtibial devices with a compressive load ofkg atHz forhoursCartilage damage will be determined with histopathology afternandnhours of cyclic testingChanges in joint mechanics will be assessed by coefficient of frictionCOFmeasurements atandhours of testingThe work outlined in this Phase I STTR will provide critical feasibility data for the development of a research strategy for commercialization of ArthroFabas a highly innovativeadditively manufactured patient specific device for small bone arthroplasty and hemiarthroplastywith the potential for a significant impact on the surgical treatment of osteoarthritis and en bloc tumor resections NARRATIVE Bone excision is central to many of the definitive treatments for end stage arthritis in the wristthough bone removal carries with it the risks of instability and weaknessThe work outlined in this proposal will determine the feasibility of fabricating replacement bones usingD additive manufacturing of the FDA cleared polymer polyetherketoneketonePEKKIf successfulthis technology could be used to replace portions of joints that have been removed in the treatment of severe arthritis or bone tumors