Cartilage and Meniscus Transplantation in the Pediatric and Young Adult Knee
By George D. Rhyneer, M.D.
Over the last fifteen years, new therapies have evolved to treat early cartilage or meniscus injuries in the adolescent and young adult. These therapies include autologous cartilage growth and transplant of donor cartilage and meniscal tissue into affected areas of the knee. Early intervention with these treatments can prevent osteoarthritis later in life, and even the need for total join replacement. Increased awareness and understanding by physicians in the community about these treatments can help teens and young adults have access to treatment that could save their joints later in life.
Some physicians and many lay individuals believe that as we age, osteoarthritis is inevitable. While the matrix of our cartilage changes in composition as we age, trauma frequently causes arthritic pain in the knee in the second to fifth decades of life. The adolescent or young adult knee can tolerate a significant amount of abuse without serious injury; often we can attribute complaints of swelling and soreness in the knee by pediatric patients to Osgood-Schlatter disease. Physicians should be leery, however, of concomitant complaints of swelling, catching and soreness that occur over time. Besides tearing of the anterior cruciate ligament (ACL) which we often reconstruct surgically, young adults can often injure two areas of the knee that are difficult to initially diagnose and treat: the articular surface of the femoral condyles and the menisci (the fibrous bushings that spread out the weight of the femur on the tibia.)
Cartilage Injuries
Articular cartilage injuries can occur with repetitive impact forces, one-time impact injuries or twisting injuries that may rupture the ACL. The cells of the articular cartilage sustain damage, and never re-grow. Injuries may not appear initially on x-ray, but over time they develop into osteochondritis dessicans (OCD). These lesions can enlarge and even break off. Smaller lesions can be detected by MRI and clinical signs i.e., swelling after playing sports. Unfortunately, due to the resiliency of surrounding cartilage, patients may not seek attention until the lesion has deteriorated to the point of causing sever pain and swelling. These look far worse inside than on x-ray and can be repaired if detected early on.
Two treatments for cartilage lesions are Autologous Cartilage Implanation (ACI) and Osteochondral Auto or Allo graft Transfer (OATS). ACI involves taking a biopsy of healthy cartilage cells from the patient's knee and growing them in a culture medium. A cartilage patch is then re-implanted over the leasion and cells placed beneath. For larger lesions, greater than 7 cm, a donor graft from a tissue bank may be implanted all at once. Cartilage plugs can also be harvested from the less used area of the articular surface for implantation to damaged areas (the OATS method). ACI is the preferred method for teens and young adults, since the patient's original cartilage is used. These technologies were established in the mid-1980s and are being done regularly in Alaska. Long term outcomes have proved successful, with active individuals returning to contact sports and recreational activities.
Meniscal Injuries
Orthopedists have dealt regularly with meniscal injuries for years, mostly by trimming away tears. Loss of meniscus over time due to trauma and arthroscopic removal decrease the bushing like effect of the meniscus and increase articular cartilage wear. Walking on an unrepaired meniscus can damage cartilage surfaces, and the meniscus itself. Early MRI is vital to the detection of meniscal injuries so the orthopedist can intervene immediately. For young adults and older patients who have significant meniscus loss due to trauma, wear or removal, meniscal allograft transplantation is available. The surgeon removes the old meniscus and grafts in a donor meniscus that acts as a construct for new cell growth.
Hopefully, with early detection of OCD and meniscus injuries through clinical exam and MRI, teens and young adults can access technologists like ACI, OATS and meniscus transplantation to avoid having pain and ultimately, a total joint surgery later in life.
For more information on this specialized transplantation performed in Anchorage, call Providence's Physicians Practice line at (907) 743-2348.
Published May 2005, Physicians Practice.
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