Analysis Of Kinematic And Biomechanical Differences In Landing Experiment After Single-bundle Anatomical Anterior Cruciate Ligament Reconstruction With And Without Remnant Preservation

Background:Anterior cruciate ligament(ACL)injury is the most common disease in sportsrelated injuries.Whether anterior cruciate ligament stump should be retained in anterior cruciate ligament reconstruction(ACLR)is still controversial.Few studies have been conducted to compare and discover the kinematic and biomechanical differences between anterior cruciate ligament reconstruction with and without remnant preservation.The differences in knee performance between the two surgical methods in special exercise modes after patients have returned to exercise is needed to be explored.Objective:To investigate the kinematic and biomechanical differences of knee joints in landing experiments after unilateral ACL remnant preservation and non-remnant preservation reconstruction after patients have returned to exercise,and to analyze the characteristics of knee movements in remnant preservation and non-remnant preservation reconstruction,so as to provide the basis for the surgeon’s choice of specific surgical methods during operation and the formulation of postoperative rehabilitation plan.Methods:Patients admitted to our hospital from January 2017 to January 2019 due to unilateral ACL injury were selected.After successfully receiving ACLR treatment,follow-up rehabilitation training was performed according to the same rehabilitation plan.After they returned to exercise,they were tested for drop vertical jump(DVJ).Two groups of subjects were the ACLR with remnant preserved group(RP group)and the ACLR without remnant preserved group(NPR group),a total of 27 people(PR group n = 16,NRP group n = 11).Collect the basic information of patients(gender,age,affected side,BMI,time interval from injury to surgery,operation time,meniscus injury,cartilage injury)and perform DVJ test after each patient’s lysholm score,KOOS score,Tegner score grade.Collect the kinematics and dynamic parameters during the landing experiment simultaneously,divide the landing experiment into two periods,the initial contact period and the landing period,and calculate the three-dimensional angles and joint moments of the sagittal and coronal planes of the bilateral knee joints in the two periods.Group t-test and paired t-test were used to compare the biomechanical differences of bilateral knee joints between and within the RP group and the NRP group.Results:There were no significant differences in lysholm score,KOOS score,and Tegner score between the RP and NRP groups(P> 0.05).There was no significant difference in the vertical ground reaction force(v GRF)between the RP and NRP groups and between the healthy and affected sides(P> 0.05).There were no significant differences in the kinematic and biomechanical parameters of the sagittal and coronal planes of bilateral knee joints between the RP and NRP groups during the landing experiment(P>0.05).The mean value of the flexion angle of the bilateral knee joints in the RP group(104.77 ± 21.76 on the healthy side and 100.25 ± 22.84 on the affected side)was larger than that in the NRP group(99.11 ± 21.03 on the healthy side,97.73 ± 18.03 on the affected side),and during the initial contact phase,the RP group’s mean flexion angles of bilateral knee joints(18.46 ± 13.65 on the healthy side and 16.21 ± 11.7 on the affected side)were smaller than those in the NRP group(20.00 ± 9.41 on the healthy side and 21.92 ± 7.41 on the affected side).However,there was no significant difference in the range of motion of the knee joint between the healthy and affected sides during landing(P = 0.251 on the healthy side and P = 0.354 on the affected side).In the RP group,there was a significant difference in the knee flexion angle between the healthy and affected sides during landing(P = 0.001).However,the limb symmetry indices(LSIs)of knee range of motion and maximum flexion angle during landing between the RP and NRP groups do not have significant differences.(RP group P = 0.679,NRP group P = 0.122).Conclusion:There were no significant differences in kinematic and biomechanical parameters of knee joint motion between ACLR with and without remnant preservation during landing experiments.Both methods can obtain good clinical treatment effect in the short term after surgery.Whether to retain ACL stump in the short term after surgery does not affect the performance of the knee joint.The surgeon can decide whether to retain ACL stump according to the specific conditions during the operation.