| Anterior cruciate ligament(ACL)injury is one of the most common knee injuries,if treated with improper measures,which may lead to severe knee joint instability,secondary cartilage damage,meniscal injury,and osteoarthritis.The clinical results and experimental studies show that early ACL reconstruction could prevent progressive osteoarthritis and functional disabilities.At present,the treatment of ACL injury focuses on the methods of arthroscopic reconstruction,reasonable graft selection,biological transformation and early postoperative rehabilitation.At present,autografts,allografts,and artificial ligaments are widely used in clinic,these graft materials have their own advantage and disadvantage for ACL reconstruction,any graft is not an ideal substitute for the natural anterior cruciate ligament.The selection of graft is very important for clinical effect,many scholars proposed to reconstruct ACL by combining autologous tendon with artificial ligament because of the advantages and disadvantages of autografts and artificial ligaments.We hypothesized that the artificial fiber bundle of combined ligaments has high resistance to fatigue in the early postoperative stages of ACL reconstruction,with the further regeneration and remodelling of the ligaments,autografts showed greater advantage in the aspect of revascularization,which can make up for the defects of late fatigue fracture of the LARS ligament.There is no basic research in this field at present,in order to make up for the shortage and verify the feasibility of this operation plan,the first and the second part of this study are designed as follows: To assess the nature and pattern of tissue ingrowth within the combined ligaments during the process of tissue reconstruction and to observe the integration between combined ligaments and bone interface by methods of histology as well as to evaluate the biomechanical behavior of the reconstructed knees at 12 and 24 weeks postoperatively.The third part aims to compare the short-term clinical effect of autologous tendon combined with allografts and solely autologous tendon or allogenic tendon in ACL reconstruction.The fourth part aims to evaluate the efficacy of LARS artificial ligament versus autologous hamstring tendon for ACL reconstruction through a meta-analysis method.This study included the following four parts: Part one The histological research of anterior cruciate ligament reconstruction in rabbits using autogenous tendon combined with LARS artificial ligamentObjective:The aim was to compare the histological changes in a rabbit model after reconstructing the anterior cruciate ligament(ACL)by solely autologous tendon and autologous tendon combined with LARS artificial ligament 12 and 24 weeks postoperatively.Methods:ACL reconstruction was performed in 48 knees from 24 healthy New Zealand white rabbits,and a controlled observation was performed for this research.The left knee was reconstructed solely with autografts(Control Group),while the right knee was reconstructed with autologous tendon combined with LARS artificial ligament(Trial Group),12 of 24 models were used for histological research and gross observation 12 and 24 weeks postoperatively.Results:1.Gross observation:The knee joint of trial group was swelling more significantly than that in the control group 12 weeks postoperatively,and joint effusion had markedly reduced 24 weeks postoperatively.The autologous tendon and artificial ligament were combined with each other more closely 24 weeks postoperatively,all combined ligaments were obviously covered by connective tissue layer.The hyperplasia of synovial tissue is obviously in the intercondylar fossa of the two groups 12 or 24 weeks postoperatively.There were no significant differences between the left and right knees regarding articular cartilage and meniscal damage.The gap between the bone-ligament interface was not obvious if we gave appropriate longitudinal traction 24 weeks postoperatively,and the combination was more closely at 24 weeks than that of 12 weeks postoperatively.2.Histological observation: There were more fibrocartilaginous tissue within the fibers located on the the bone-ligament interface 24 weeks postoperatively;organized,perpendicular,sharpey-like collagen fibers were observed between the artificial ligament and surrounding bone;new vascular tissue and fibroblasts can be seen occasionally among the fiber bundles of artificial ligament;the ligament-bone interface had not clear boundaries,but no any new-bone tissue formation can be seen.There were connective fibrous tissue ingrowth between the fascicles and LARS ligaments fibers in the intra-articular portion of artificial ligaments.The fibers of the LARS ligament prosthesis were gradually filling with fibrous tissue,and the collagen fibers appeared to be more oriented at 24 weeks.Autologous tendon fibers and artificial ligament fibers were intertwined with each other,there were no obvious inflammatory cell infiltration between the autologous tendon and the LARS artificial ligaments.Conclusions:Reconstructing the ACL in rabbits using autologous tendon combined with the LARS artificial ligament results in satisfactory biointegration 12 or 24 weeks postoperatively,with no obvious immunological rejection between the autologous tendon and the artificial ligament,both of them can form an effective fibrous connection between the ligament-bone interface.Part two The biomechanical research of anterior cruciate ligament reconstruction in rabbits using autogenous tendon combined with LARS artificial ligamentObjective: The aim is to combare the biomechanical change after ACL reconstruction in the rabbits using autogenous tendon combined with the LARS artificial ligament vs autogenous tendon 12 and 24 weeks postoperatively.Methods: Twelve rabbits were randomly selected to euthanize 12 and 24 weeks postoperatively.At each of the two time points,rabbits were processed for biomechanical tests(n=24 knees).The prepared knee specimens were embedded in steel cylinders,and the flexion angle of the knee joint was set to align the axis of the applied load with the ACL direction.Maximum load to failure was calculated from the load-displacement curve,and failure modes were recorded for each tested specimen.Results:1.The respective failure load in the control group and trial group were 144.15 ± 3.92 N and 140.88 ± 2.75 N 12 weeks postoperatively,all the ACL grafts were pulled out from the bone tunnel 12 weeks postoperatively.4 cases of control group were pulled out from tibial bone tunnel with the failure load 148.27 ± 2.93 N;8 cases were pulled out of femoral tunnel with the failure load of 142.36 ± 2.83 N.In the trial group,9 cases were pulled out of femoral tunnel with the failure load of 138.03 ± 1.94 N,3 cases were pulled out of tibial tunnel with the failure load of 147.95 ± 2.36 N.2.The respective failure load in the control group and trial group were 184.15 ± 1.96 N and 180.88 ± 3.21 N 24 weeks postoperatively.3 cases of control group were pulled out from tibial bone tunnel with the failure load 162.36±1.19 N;4 cases were pulled out from femoral tunnel with the failure load of 160.37±2.01 N,five specimens failed at the midsubstance portion or tunnel mouth with the failure load of 218.89±1.32 N,without being pulled out from the bone tunnel.In the trial group,5 cases were pulled out of femoral tunnel with the failure load of 165.29±1.57 N,4 cases were pulled out of tibial tunnel with the failure load of 168.32±1.58 N,3 cases failed at the midsubstance portion or tunnel mouth with the failure load of 222.96±1.35 N.3.The failure load of two groups were improved significantly from 12 weeks to 24 weeks,there was significant difference between 12 weeks and 24 weeks posroperatively(P<0.05),but there was no significant difference between control group and trial group 12 or 24 weeks postoperatively(P>0.05).40 cases were pulled out from the bone tunnel 12 and 24 weeks postoperatively.Conclusions: In a rabbit model of ACL reconstruction,the biomechanical properties of autogenous tendon group and combined ligament group 24 weeks postoperatively were significantly better than that of 12 weeks postoperatively,there were no significant difference between the two groups 12 or 24 weeks postoperatively,the ligament-bone interface was still the weakest part during the process of ACL reconstruction.Part three Comparison of anterior cruciate ligament reconstruction using autologous tendon combined with allogeneic tendon and solely autologous tendon or allogeneic tendonObjective:The aim is to investigate the clinical effects of ACL reconstruction using autologous tendon combined with allogeneic tendon and solely autologous tendon or allogeneic tendon.Methods:From January 2014 to December 2015,clinical data of 98 patients with ACL injury underwent arthroscopic reconstruction were analyzed retrospectively in the third Hospital of Hebei Medical University.According to different kinds of reconstruction grafts,the patients were divided into three groups:Group A: combined ligament group(n = 33);Group B: autologous tendon group(n = 35);Group C: allogeneic tendon group(n = 30).Differences of ADT test positive rate and Lachman test positive rate were analyzed among three groups at the last follow up;Lysholm scores,International Knee Documentation Committee(IKDC)scores were recorded to evaluate knee joint function,and the stability of knee joint was examined by KT-1000 arthrometer.Results:1.All the patients were followed up at an averge of 14~24 months,the average operation time of Group C is shorter than both Group A and Group B(P<0.001),and the fever time of Group C is longer than both Group A and Group B(P<0.001).No patients had ligament rerupture,deep vein thrombosis,exfliation of interference screw and joint infection.There were no difference among three groups in the stability and ROM of knee joint.2.The positive rate of ADT and Lachman test of three groups showed significantly difference before and after operation(P < 0.001);There were no significant differences among three groups regarding ADT and Lachman test positive rate at the last follow-up.3.There were no significant differences among three groups regarding the results of KT-1000 at the last follow-up,KT-1000 results also showed that the stability of knee joint was significantly improved at the last follow-up compared with preoperative,and the difference was statistically significant(P<0.001).4.The Lysholm and IKDC score of three groups showed significantly difference before and after operation(P<0.001);there were no significant difference regarding the Lysholm score and IKDC score among three groups at the last follow-up.Conclusions: The clinical outcome of ACL reconstruction using all the above three grafts were satisfactory,allogeneic tendon group has a longer fever time,the combined ligaments is easier to control in terms of structural characteristics,and the donor site is less damaged,which could be a good substitute for autologous tendon.Part four Comparison of LARS artificial ligament versus four strand hamstring tendon autograft for anterior cruciate ligament reconstruction: a meta-analysisObjective:The aim is to systematically evaluate the efficacy of LARS artificial ligament versus four strand autologous hamstring tendon for arthroscopic anterior cruciate ligament reconstruction.Methods:The related articles published from January 2007 to January 2018 were electronically searched.According to the specific inclusion and exclusion criteria,the articles were selected,and then the data were collected and analyzed using Stata 11.0(Stata Corporation,College Station,TX)software.Results:A total of 12 controlled clinical trials and a total of 606 patients were included,in addition to one study in English,all of them are Chinese Literature.A statistical difference was found in the Lysholm score at both 3 and 6 months after surgery between LARS artificial ligament and autologous hamstring tendon,and the LARS artificial ligamen had a significantly higher score.Similar results were also observed for Tegner knee score and IKDC score.However,at 12 months,only the Tegner knee score was higher in the LARS artificial ligament group.At 18 months and 24 months,there was no significant advantage of the LARS artificial ligament over the autologous tendon with regard to all the three scores mentioned above.There were no significant differences between autologous tendon group and LARS artificial ligament group of the surgical knee regarding the the results of KT-1000 at the last follow-up.Conclusions : The results of this meta-analysis suggest that LARS artificial ligament has a better clinical outcome than autologous hamstring tendon within 12 months of surgery,and after 24 months,their clinical outcomes are equivalent. |
PDF Full Text Request