The Analysis Of Clinical Effects And Biomechanics Of Anterior Cruciate Ligament Reconstruction With Internal Tension-relieving Technique

Part 1:Clinical effects of anterior cruciate ligament reconstruction with internal tension-relieving techniqueObjective:To study the clinical curative effects of ACL reconstruction with internal tension-relieving technique from knee function and second-look arthroscopyMethods:From July 2017 to July 2019,80 cases were qualified for the selective standard of complete ACL rupture,All cases were randomly divided into 2 groups:ACL reconstruction with internal tension-relieving technique was performed in 40 cases(tension-relieving group),arthroscopic assisted ACL reconstruction in 40 cases(non tension-relieving group).All patients were received IKDC、HSS、Lysholm knee questionnaires before and 3,6,12 months post the operation.The reconstructed ACL underwent second-look arthroscopic evaluation 12 months post the operation and the effectiveness were evaluated according to the criteria of AO Yingfang and MAS.Results:All patients had a great recovery,and no early complication was found.The scores of IKDC,HSS and Lysholm of the two groups had gradually increased post the operation(P＜0.05).The scores of tension-relieving group were higher than non tension-relieving group in the same time post the operation(P＜0.05).It was significant that the tension-relieving group could obtain better subjective scores of IKDC,HSS and Lysholm.According to the second-look arthroscopy criteria of Ao Yingfang,there were no significant difference in the condition of graft continuity,synovial coverage,lustre between two groups(P＞0.05).Furthermore,tension-relieving group was better than non tension-relieving group in the condition of tension and total scores(p＜0.05).The excellent rate of ligaments in tension-relieving group is higher than that in non tension-relieving group according to the MAS.Conclusion:ACL reconstruction with internal tension-relieving technique could effectively recovery knee instability,and ACL reconstruction with the tension-relieving technique was superior to non tension-relieving in the subjective evaluation.ACL reconstruction with internal tension-relieving technique could achieve great ligament integrity and ligament lustre、synovial membrane coverage.The tension-relieving technique is obviously better than non tension-relieving in the condition of tension and total scores.Part 2:The knee joint kinematics analysis post-operation of anterior cruciate ligament reconstruction with internal tension-relieving technique.Objective:To analyze the knee joint kinematics data of anterior cruciate ligament reconstruction with internal tension-relieving technique.Methods:The data of relative anterior-posterior displacement,up-down displacement,media and external displacement,media and external rotation angles,flexion and extension angles,valgus and varus angles of the 80 patients and 40 healthy volunteers had been recorded and statistics analyzed pre-operation and 12 months post-operation with Opti_KneeTM 3D knee motion analysis system.Results:The data of anterior-posterior displacement,up-down displacement,media and external displacement,media and external rotation angles of the injured knees in the both two surgical groups are decreased compared with those before operation(P ＜0.05).And there was significant difference in anterior-posterior displacement between the two groups(P＜0.05),tension-relieving group was better than non tension-relieving group.The anterior-posterior stability of the knee joint in tension-relieving group is close to that of normal adults(P＞0.05),but AP stability in non tension-relieving group is slightly worse than that of normal adults(P＜0.05).Conclusion:Tension-relieving group could achieve better knee joint stability than that in non tension-relieving group,especially in the aspect of anterior-posterior stability.Part 3:A biomechanical measurement of tension-relieving suture and hamstring tendonObjective:To measure the elastic modulus and failure loads of tension-relieving suture and hamstring tendon,providing mechanical theory basis for anterior cruciate ligament reconstruction with internal tension-relieving technique.Methods:To measure the elastic modulus and failure loads for single Ethibond suture,tension-relieving suture,one-stranded tendon graft,four-stranded tendons graft(" looped graft"),looped graft combined with tension-relieving suture by biomechanical machine.Then perform statistical analysis in all datum.Results:The failure load of looped graft is bigger than that of looped graft combined with tension-relieving suture(P＜0.05),but the elastic modulus of the looped graft combined with tension-relieving suture is same as looped graft(P＞0.05);The elastic modulus of the looped graft is same as one-stranded tendon graft(P＞0.05).The elastic modulus of the tension-relieving suture is far less than double Ethibond sutures(P＜0.05).Conclusion:The elastic modulus of tension-relieving suture is close to hamstring tendon.Therefore,the tension-relieving suture could increase significantly the tensile strength of looped graft,it’s good for ligamentalization of the graft.Part 4:3D finite element analysis study on anterior cruciate ligament reconstruction with internal tension-relieving technique.Objective:A simulated Lachman maneuver was performed in 3-D knee joint model to assess knee joint laxity(AP translation),Peak von Mises(vM)stresses for ACL graft.Providing mechanical datum for ACL reconstruction with internal tension-relieving technique.Methods:To apply MRI scanner to scan the knee joints of one healthy volunteer.The data were collected,next import 2-D images into MIMICS 19.0,to construct a 3-D finite element model on femorotibial joint via 3-D digitalization and reverse engineering technologies.Based on the model without tension-relieving suture to build another one which is with tension-relieving suture.Import the established model into ANSA in STL format for further processing to gemerate the geometric models.Finally,Importing the models into Abaqus to mesh,4 sets of simulated Lachman maneuver were utilized to assess knee joint laxity(AP translation),Peak vM stresses of ACL for model with tension-relieving suture,as well as a suture-deficient knee.To perform statistical analysis in the biomechanical datum.Results:There is significant difference in anterior-posterior displacement between the model with tension-relieving suture and model without tension-relieving suture(P<0.05),tension-relieving suture could decrease significantly the AP translation of tibia;There is significant difference in peak ACL graft vM stress between the model with tension-relieving suture and model without tension-relieving suture(P<0.05),tension-relieving suture could decrease significantly the peak vM stress of ACL graft.Conclusion:The model with tension-relieving suture was with less peak vM stress,decreased joint laxity in comparison with the model without suture.Therefore,the current datum suggest that ACL reconstruction with tension-relieving technique confers a biomechanical advantage in the ACL reconstructed knee.