A Visualized Sensitized Acupoint Procedure for Knee Osteoarthritis: Behavioral, Thermal, and Molecular Assessments

Knee osteoarthritis (KOA), a leading cause of musculoskeletal pain and functional disability worldwide, remains challenging to manage due to the limited efficacy of current pharmacological and surgical interventions in achieving sustained pain relief. Although acupuncture has demonstrated clinical promise in alleviating KOA-related pain, its underlying mechanisms require further elucidation. Application of acupuncture to sensitized acupoints can markedly enhance the effectiveness of therapy. This protocol establishes a rat model of KOA through intra-articular injection of sodium monoiodoacetate (MIA) and systematically describes an acupuncture protocol targeting sensitized acupoints, including restraint methods, acupoint localization, and acupuncture parameters. Therapeutic efficacy was comprehensively evaluated through pain behavioral assessments, infrared thermographic analysis of the knee joint, inflammatory cytokine detection in serum, and histopathological examination of cartilage tissue. Results indicate that acupuncture at sensitized acupoints significantly alleviates pain phenotypes in MIA-induced model rats by inhibiting the release of pro-inflammatory mediators, blocking nociceptive signal transmission, improving blood microcirculation, regulating local joint temperature, and delaying joint degeneration.