Extracorporeal Shock Wave Technology Repairs Osteoarthritis Damage

A novel preclinical study suggests that extracorporeal shock wave technology (ESWT) has chondroprotective effects in the osteoarthritic rat knee.

Researchers at Kaohsiung Chang Gung Memorial Hospital (Taiwan) utilized three groups of Sprague-Dawley rats, each containing nine animals. The rats in the control group did not have their anterior cruciate ligaments (ACL) surgically cut, whereas animals in the other two groups underwent surgical ACL transection (ACLT) in order to induce osteoarthritis (OA). Of the two ACLT groups, one group received a single ESWT procedure immediately following ACLT, while the other group received no treatment of any kind after ACLT. All animals underwent evaluations including radiograph, bone mineral density, serum levels of cartilage oligometric protein and osteocalcin, and urinary concentration of C-telopeptide of type II collagen (CTXII), and histomorphological examination.

The results showed that a single ESWT procedure prevented or significantly improved surgically induced OA damage to the knee in the rat model, significantly decreased articular cartilage degradation, and improved subchondral bone remodeling. When treated with ESWT, the surgically compromised OA knees displayed comparable data to the control group of normal, healthy knees at 12 weeks post-treatment. Multiple analyses of articular cartilage, subchondral bone, and blood and urine protein markers suggest that early application of ESWT provides a chondroprotective effect to prevent OA onset. The study was published on June 9, 2011, in the online edition of Archives of Orthopedic Trauma Surgery.

"Based on these positive study results, ESWT treatment may offer an effective, low-cost treatment option in humans that carries little risk compared with other treatments," said lead author orthopedic surgeon Ching-Jen Wang, MD. "This study is clinically relevant because it validates our original theory that ESWT treatment has a chondroprotective effect that repairs and prevents osteoarthritic changes in the knee joint."

ESWT is a method of treatment for multiple musculoskeletal conditions. Presently it is only approved by the US Food and Drug Administration (FDA) for treatment of plantar fasciitis and tennis elbow. ESWT probably works due to the microtrauma of the repeated shock wave to the affected area, which creates neovascularization into the area. It is this new blood flow that promotes tissue healing. A second theory is that in chronic pain, the brain has "forgotten" about the pain and is doing nothing to heal the area. By having shockwave therapy, a new inflammatory process is created and the brain can react to it by sending the necessary body nutrients to the area to promote healing.

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Kaohsiung Chang Gung Memorial Hospital