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More Results from the STAR Study

The STAR study (which stands for Study of the Treatment of Articular Repair) was started back in the early 2000s by the Genzyme Corporation, an FDA-licensed facility. This laboratory takes patients' healthy chondrocytes (cartilage tissue) and grows more normal, healthy cells.

The laboratory grown chondrocytes are then used to fill in holes in the joint surface of the knee. These holes or defects occur in the joint surface cartilage and first layer of bone under the cartilage. They are caused by a condition known as osteochondritis dissecans (OCD). The goal of the STAR study was to see how well autologous chondrocyte implantation or ACI works for osteochondritis dissecans (OCD).

There's an added little twist to the STAR study. And that is -- each of the patients included already had one failed surgery for severe (full-thickness) lesions. In this new study, 32 more patients who met these criteria (severe lesions, 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 were reported on.

Outcomes of treatment were measured based on patient report of pain and other symptoms (swelling, tenderness) as well as activity and function. Activities included return to sports or physical recreation. Function was 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 this STAR study had a successful repair of their severe osteochondritis lesion using autologous chondrocyte implantation (ACI). Although it was two years before the repair tissue was mature enough to mimic normal tissue, patients reported pain relief and functional improvement early on. And those positive results continued for the full four years of the study follow-up period.

Factors that affected outcomes included 1) chronicity of the disease (i.e., how long they had it), 2) severity (how deep and wide were 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 was present increased 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.

The results of this study are consistent with the results of other, similar STAR studies. Pain reduction and improved function lasting up to 48 months can be expected after autologous chondrocyte implantation (ACI). Keep in mind the patients in the STAR study have all had one previous failed surgical treatment.

ACI is not the first choice for treatment of osteochondritis dissecans (OCD). But as the STAR study has shown, it is a good "rescue" option when other methods fail for severe, chronic cases.

Brian J. Cole, MD, COL (Ret), et al. Outcomes of Autologous Chondrocyte Implantation in Study of the Treatment of Articular Repair (STAR) Patients with Osteochondritis Dissecans. In The American Journal of Sports Medicine. September 2012. Vol. 40. No.9. Pp. 2015-2022.


*Disclaimer:* The information contained herein is compiled from a variety of sources. It may not be complete or timely. It does not cover all diseases, physical conditions, ailments or treatments. The information should NOT be used in place of visit with your healthcare provider, nor should you disregard the advice of your health care provider because of any information you read in this topic.
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