Innate Immune Response in Orthopedic Implant Failure

Effects of Aging on Osteosynthesis at Bone-Implant Interfaces

Joint replacement is a common surgery and is predominantly utilized for treatment of osteoarthritis in the aging population. The longevity of many of these implants depends on bony ingrowth. Here, we provide an overview of current techniques in osteogenesis (inducing bone growth onto an implant), which is affected by aging and inflammation. In this review we cover the biologic underpinnings of these processes as well as the clinical applications. Overall, aging has a significant effect at the cellular and macroscopic level that impacts osteosynthesis at bone-metal interfaces after joint arthroplasty; potential solutions include targeting prolonged inflammation, preventing microbial adhesion, and enhancing osteoinductive and osteoconductive properties.

Biomechanical Forces in the Tissue Engineering and Regeneration of Shoulder, Hip, Knee, and Ankle Joints

Tear on the tendon, ligament and articular cartilage of the joints do not heal by itself and new modalities of treatment are required to address the need for full restoration of joint functions. Accompanied by degenerative diseases, the healing of these tissues does not occur naturally and hence requires surgical interventions, but with associated morbidity. Tissue engineering strategies are now focusing on the effective incorporation of biomechanical stimulation by the application of biomechanical forces relevant to the tissue of interest to regenerate and engineer functional tissues. Bioreactors are being continuously developed to accomplish this goal. Although bioreactors have been developed, the advancement in the field of biomaterial, basic science, and cell engineering warrant further refinement for their effective use. In this article we reviewed the application of biomechanical forces in the tissue engineering and regeneration of the joints such as rotator cuff of shoulder, ball and socket joint of the hip, articular cartilage of knee, and the ankle joints.

Peripheral Nerve Regeneration: Opportunities and Challenges

Peripheral nerve injury has detrimental effects on the quality of life for patients and is a worldwide issue with high rates of morbidity. Research on the molecular mechanisms of nerve injury, microsurgical techniques, and advances in stem cell research have led to substantial progress in the field of translational neurophysiology. Current research on peripheral nerve regeneration aims to accelerate peripheral nerve development through pluripotent stem cells and potential use of smart exosomes, pharmacological agents, and bioengineering of nerve conduits. In this article critically reviewed and summarized various methods used for peripheral nerve regeneration and highlight the opportunities and challenges that come along with these strategies.