Off-The-Shelf Surgical Device to Help Avoid Total Knee Replacement

Osteochondral defects (OCDs) lead to damage in both cartilage and the underlying bone, often resulting in chronic pain and a loss of joint function. Treatment options vary depending on the severity of the damage and typically include autografting or total knee replacement. Autografting involves harvesting small cylindrical specimens from unaffected areas of the knee and implanting them into the damaged area. This method may be less effective in patients over 40 or those with large defects. When autografting is unsuitable, patients may require a total knee replacement, an extensive procedure where damaged knee components are replaced with a metal and plastic prosthetic. Although often necessary, this surgery can lead to various post-operative complications. To address these challenges, researchers have now developed synthetic cartilage-capped regenerative osteochondral plugs (CC-ROPs), a promising off-the-shelf surgical device to potentially avoid total knee replacements.

These CC-ROPs, created by researchers at Texas A&M University (College Station, TX, USA), are composed of two elements: a cartilage cap and an osseous (bone) base. The cartilage cap is made from an ultra-strong hydrogel that effectively replicates the mechanical attributes of natural cartilage, while the base consists of a porous, bioresorbable polymer. Once the CC-ROP is implanted, the bone base is gradually replaced by new bone tissue, helping to secure the cartilage cap and promote the integration of the implant with the existing bone, thus maintaining necessary joint function. The design of the CC-ROPs is such that they are not limited by the patient's age or defect size.

Image: A synthetic cartilage-capped regenerative osteochondral plug being implanted into a knee (Photo courtesy of Texas A&M Engineering)

Additionally, these plugs are shaped like traditional cylindrical autografts, allowing them to be inserted using standard surgical tools and techniques. They do not need to be pre-loaded with cells or growth factors to facilitate healing, relying instead on the inherent properties of the cap and base to aid recovery. Upon implantation, the CC-ROP immediately supports joint function, including movements like knee articulation. The research team is focused on enhancing the therapeutic potential of these devices, conducting rigorous analyses to verify their functionality and readiness for clinical use. They are also planning to assess the efficacy of the CC-ROPs in pre-clinical trials.

“Chronic knee pain and disability are caused by cartilage loss and OCDs stemming from arthritis, including osteoarthritis and post-traumatic arthritis causing individuals pain that limits comfort and mobility,” said Dr. Melissa Grunlan, professor in the Department of Biomedical Engineering at Texas A&M University. “Overall, this design represents a feasible approach for clinical translation.”

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