Alleviation of cartilage degeneration by laser acupuncture: An ultrasound biomicroscopic study of early postmenopausal osteoarthritis in rats

Abstract

This study aims to evaluate the therapeutic effects of laser acupuncture (LA) on articular cartilage degradation at the early stage of postmenopausal osteoarthritis (PMOA) by an ultrasound biomicroscopic technology. Twenty-one healthy female Sprague-Dawley rats were randomly and evenly divided into three groups - sham, ovariectomized (OVX) and OVX ​+ ​LA groups. Only the peri-ovarian fatty tissue of the sham rats was exteriorized. The animals in the OVX and OVX ​+ ​LA groups underwent bilateral ovariectomy to create a menopause model. On day 8 after the ovariectomy, the 2-week LA therapy at acupoints Guanyuan (CV-4), Sanyinjiao (SP-6), and Zusanli (ST-36) was performed in the OVX ​+ ​LA group, while the sham and OVX groups had a sham treatment. All the animals were sacrificed on day 22. The cartilage tissues in the left knee joint were examined by ultrasound and histology. Compared with the sham group, the significantly degenerate alterations (p ​< ​0.01) in ultrasound roughness index (URI), reflection coefficient (RC1) and cartilage thickness were found in the OVX group, while the values of these parameters were significantly recovered (p ​< ​0.01) in the OVX ​+ ​LA group. The LA treatment enhanced proteoglycans (PGs) content with a significant reduce of the modified Mankin score (p ​< ​0.01). The acoustic assessment strongly correlated with the histologic evaluation. The results showed that LA treatment could alleviate the postmenopause-induced cartilage degradation and promote tissue repair. LA has potential to be a simple and safe non-pharmacological countermeasure against PMOA for geriatric patient population. The ultrasound biomicroscopic technology could be a quantitative evaluation tool of the structural and morphological responses of articular cartilage to LA intervention.