Assessing the Effect of Manufacturing Processes on a Developed Osteochondral Implant

Isabel Finnegan

Abstract

Approximately two million people in the US required surgery between the years of 2004-2011 to repair focal chondral and osteochondral defects. These conditions cause a “pothole” to form in knee joint cartilage and bone. Leaving defects untreated eventually leads to the development of osteoarthritis, requiring total joint replacement. One method for repairing these is filling them with an osteochondral implant; however, currently, implants do not mimic native osteochondral physiology and have limited availability and shelf-life. To combat this issue, the Ortho-X lab developed a novel osteochondral implant comprising of two parts: a cartilage analog (CA) and a subchondral bone (ScB) surrogate. Together, they provide multiple advantages, including biomimetic mechanical properties and being biologic in nature instead of synthetic. The aims of this research were to evaluate the effects of annealing and sterilization on the structure of the cartilage analog and to determine how long-term submersion in simulated body fluid affects the mechanical strength of the subchondral bone surrogate. Cartilage analogs (n = ~7/group; non-annealed, annealed, annealed + sterilized) were evaluated histologically for changes in micro-architecture and proteoglycan content. Results from the CA study showed the sterilized + annealed samples had the highest average proteoglycan content and best microarchitecture. ScB samples were immersed in simulated body fluid, water, or simulated OA synovial fluid for 3 months prior to performing compressive mechanical testing. Results from the ScB study indicated that ScBs typically perform best in body fluid. Altogether, the developed constructs are well-suited for implantation even after undergoing the various manufacturing processes.

 
Mar 30th, 11:15 AM

Assessing the Effect of Manufacturing Processes on a Developed Osteochondral Implant

Founders Hall 111 A

Approximately two million people in the US required surgery between the years of 2004-2011 to repair focal chondral and osteochondral defects. These conditions cause a “pothole” to form in knee joint cartilage and bone. Leaving defects untreated eventually leads to the development of osteoarthritis, requiring total joint replacement. One method for repairing these is filling them with an osteochondral implant; however, currently, implants do not mimic native osteochondral physiology and have limited availability and shelf-life. To combat this issue, the Ortho-X lab developed a novel osteochondral implant comprising of two parts: a cartilage analog (CA) and a subchondral bone (ScB) surrogate. Together, they provide multiple advantages, including biomimetic mechanical properties and being biologic in nature instead of synthetic. The aims of this research were to evaluate the effects of annealing and sterilization on the structure of the cartilage analog and to determine how long-term submersion in simulated body fluid affects the mechanical strength of the subchondral bone surrogate. Cartilage analogs (n = ~7/group; non-annealed, annealed, annealed + sterilized) were evaluated histologically for changes in micro-architecture and proteoglycan content. Results from the CA study showed the sterilized + annealed samples had the highest average proteoglycan content and best microarchitecture. ScB samples were immersed in simulated body fluid, water, or simulated OA synovial fluid for 3 months prior to performing compressive mechanical testing. Results from the ScB study indicated that ScBs typically perform best in body fluid. Altogether, the developed constructs are well-suited for implantation even after undergoing the various manufacturing processes.