Stress Impact On Meniscus After Electro-Acupuncture Treatment By 3-Dimention Finite Element Analysis In Knee Osteoarthritis

Objective:Three-dimensional finite element model and gait analysis method were combined not only to observe stress changes in lateral and medial meniscus after electroacupuncture treatment of knee osteoarthritis in patients, but also to analyse biomechanical changes and other possible factors contributed to such change, This study aims to provide an objective evaluation method for rehabilitative effect of knee osteoarthritis and a basis for further study on acupuncture’s therapeutic mechanism from biomechanical perspectives.Methods:1.Knee MRI images of a male and a female volunteers were scanned, four finite element model were built by using Mimics, Geomagic, Ansys software. Two volunteers’ three-dimensional gait data obtained by Motion Analysis System was imported to finite element model. The dynamic finite element model was built and verified.2. All cases came from the communities nearby to our affiliated hospital. Based on the inclusion and exclusion criteria,26 patients with the knee osteoarthritis were recruited and randomized into Electro-acupuncture group (treatment group)or pain-killer patch group (control group) by random number method. Each group consisted of 13 cases. Outcome measurement was assessed before and after treatment, including Western Ontario and McMaster Universities Arthritis (WOMAC) Index and stress change on medial and lateral meniscus.Results:1. Four knee models were stablished, combined with three-dimensional gait analysis data, the solid three-dimensional finite element model was made into a dynamic finite element model. The model was validated with the results obtained by the model and data and showed high reliability, indicated feasible in clinical studies.2.After the treatment, WOMAC index on total score, subscales of pain, stiffness and physical function was significantly lower than that before treatment in both treatment group and control groups (P <0.05). Decrease of pain score in WOMAC index was more significant in treatment group than that in control group after treatment(P<0.05). These results indicated the improvement of symptoms and daily functions in both groups. Electro-acupuncture is more effective on pain relief than pain-killer patch.3. After the treatment, we analyzed biomechanical index and found stress on medial and lateral meniscus was lower than before in both groups(P<0.05), which indicated that both acupuncture and pain-killer patch could improve knee osteoarthritis internal biomechanical environment by reducing stress on meniscus. But no significant difference showed on stress change between the two groups (P>0.05).Conclusion:1.Knee dynamic finite element model can well reflect stress change in meniscus during human gait, and biomechanical environment in human knee joint can be simulated in such model.2. Electro-acupuncture treatment is good for. knee osteoarthritis with effects on functional improvement and stress decrease on both medial and lateral meniscus. Dynamic finite element model may be used with gait analysis system to evaluate the efficacy of acupuncture on KOA. The further study on acupuncture’s mechanism including the effect of muscles from biomechanical perspective is warranted.