Effects Of Nerve Growth Factor And Substaace P In Synovium Of Knee Osteoarthritis

Objective: To investigate the pathogenesis of pain around the medial joint of knee osteoarthritis, we observed the expressions of nerve growth factor(NGF) and substance P(SP) in medial, lateral, and suprapatellar sites of knees with osteoarthritis or with only meniscus tear.Methods: The expressions of nerve growth factor and substance P were detected using immunohistochemical staining. Gless' nerve fiber staining was used to observe the distribution of nerve fibers in synovium of the knee.Results: Nerve growth factor was present as a granular pattern in the muscular wall of the vessels in synovium. NGF positive vessel rates in the medial synovium of knee osteoarthritis (67.2%) were higher than those in lateral synovium (47.6%) (P<0.05) and suprapatellar synovium (29.9%) (P0.01) and those in medial (38.9%), lateral (41.0%), and suprapatellar synovium (32.2%) of knees with only meniscus tear (P<0.01). substance P was detected as a granular pattern in the vessel walls in synovium. SP positive vessel rates in the medial synovium of knee osteoarthritis (61.7%) were obviously higher than those in lateral synovium (46.5%) (P<0.05) and suprapatellar synovium(31.6%) (P<0.01) and those in medial (43.1%), lateral (40.5%) and suprapatellar synovium (33.2%) of knee with only meniscus tear (P<0.01). Nerve fibers existed widely in synovium of the knees, especially around the vessels, forming the nerve networks around the vessels.Conclusion: The expressions of nerve growth factor and substance P in medial synovium of knee osteoarthritis are significantly higher than those in other sites. It is consistent with the findings that patients with knee osteoarthritis have obviously pain and tenderness in the medial knee. It may be the cause of the pain.