Extracorporeal shock-wave therapy reduces progression of knee osteoarthritis in rabbits by reducing nitric oxide level and chondrocyte apoptosis

The goal for treating osteoarthritis (OA) is finding ways to decrease joint pain and dysfunction and prevent and slow the cartilage degeneration. Extracorporeal shock-wave therapy (ESWT) has been found to improve motor dysfunction and ameliorate pain with OA in animals. However, few studies have found that it can prevent and slow joint degeneration in vivo. The aim of study was to investigate the effect of ESWT on OA in rabbit. A total of 30 male New Zealand white rabbits were divided into 3 groups: control, OA induced by anterior cruciate ligament transaction (ACLT), and ALCT plus ESWT. The animals were killed at 4 and 8 weeks. Nitric oxide (NO) level was measured in the synovial cavity of knee joints, and cartilage sections were graded macroscopically by a Mankin scoring system. Chondrocyte apoptosis was investigated by flow cytometry and the expression of active caspase 3 by indirect immunohistochemistry. ESWT significantly reduced the NO level in the synovial cavity of knee joints (P < 0.05) and chondrocyte apoptosis (P < 0.05) of rabbits with OA. ESWT treatment significantly decreased the severity of cartilage lesions at both times as compared to rabbits with OA alone (P < 0.05). ESWT reduced the progression of OA in rabbits. This effect may be related to decreased level of NO and is likely mediated by reduced chondrocyte apoptosis. ESWT may be a useful treatment for knee OA.