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I am getting set up to have a special surgery for my knee. It's called ACI. I'm trying to do a little research and see how other people who have this operation done come out. Do you have any suggestions where I can look?

We can help you right here! ACI or autologous chondrocyte implantation is a surgical procedure used in the knee for a condition known as osteochondritis dissecans (OCD). With OCD the surface of the knee joint surface is damaged and doesn't heal naturally. OCD mostly affects the femoral condyles of the knee. The femoral condyle is the rounded end of the lower thighbone, or femur. Like most joint surfaces, the femoral condyles are covered in articular cartilage. Articular cartilage is a smooth, rubbery covering that allows the bones of a joint to slide smoothly against one another. The problem occurs where the cartilage of the knee attaches to the bone underneath. The area of bone just under the cartilage surface is injured, leading to damage to the blood vessels of the bone. Without blood flow, the area of damaged bone actually dies. This area of dead bone can be seen on an X-ray and is sometimes referred to as the osteochondritis lesion. Autologous chondrocyte implantation (ACI) is a fairly new treatment approach developed in the last 10 years. It is currently being studied closely. It involves using the patient's own cartilage cells (chondrocytes) to help regenerate articular cartilage. The laboratory where the chondrocytes are grown for the ACI procedure is conducting a study they call STAR: Study of the Treatment of Articular Repair. In the STAR study, patients who have severe lesions and one failed surgery were treated with autologous chondrocyte implantation (ACI) and then followed for the next four years. The results of treatment and analysis of factors that might improve treatment are periodically reported on as more people enter the study. Outcomes of treatment are measured based on patient report of pain and other symptoms (swelling, tenderness) as well as activity and function. Activities include return to sports or physical recreation. Function is measured by patients' perception of their quality of life and ability to perform activities of daily living (walking, climbing stairs, getting up and down, returning to work). The majority of patients in the STAR study have a successful repair of their severe osteochondritis lesion using autologous chondrocyte implantation (ACI). Although it is two years before the repair tissue is mature enough to mimic normal tissue, patients report pain relief and functional improvement early on. Factors identified so far that affect outcomes include 1) chronicity of the disease (i.e., how long it has been present), 2) severity (how deep and wide are the lesions), 3) delays in treatment, and 4) age (adults versus teens). As you might expect from the listed factors, the larger the defect and the longer it is present, the greater the risk of a poor outcome. Likewise, a long delay between diagnosis and treatment is an added predictive factor of worse results. And the timing of treatment is linked with age. Patients who develop OCD in their teen years but aren't treated until they are adults tend to have a lower success rate than those patients who are treated during their adolescent years. One of the other positive features of this procedure is the fact that it can be used when other surgeries fail to produce the desired results (pain relief, improved knee function). There are some side effects of the procedure that may be undesirable. These include cartilage injury and graft overgrowth. About one-third of the patients in the STAR studies have developed these adverse events but they are not considered a treatment "failure". A follow-up surgery may be needed to remove the extra tissue in the case of overgrowth or to attempt another cartilage repair. The majority of patients (85 per cent or more) who have an ACI procedure for osteochondritis dissecans (OCD) have good results with high rates of patient satisfaction. OCD is a complex and challenging problem but successful treatment is possible.


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