| Objective: Anterior cruciate ligament(ACL)rupture is a common disease in sports medicine.During initial period it will lead to joint instability,limitation of motion.Then it will decrease playing level and accelerate knee degeneration at a specified future date.In most cases,treatment involves surgery.ACL repair with arthrotomy used to be the mainstay of treatment.However,this procedure was gradually abandoned due to poor prognosis in long-term follow-up.Therefore,ACL reconstruction gradually became the gold standard of treatment.With decades of development,the procedures of ACL reconstruction has became increasingly mature,but there are still a lot of unsatisfactory results in the subjective and objective evaluation of postoperative knee function,the re-operation rate and secondary injury rate remain high.This may associated with the loss of proprioceptive function and kinetic stability of the knee joint.Considering the current unsolvable dilemma of ACL reconstruction,arthroscopic ACL repair has regained attention.ACL primary repair has inherent advantages compare with the ACL reconstruction,which includes no risk of disease transmission,no rejection reaction,no accompanying damage due to autogenous tendons obtained,retaining the native proprioceptors,no re-ligamentous process in tendon graft,be consistent with the original ACL anatomical morphology.Studies have pointed out that the poor long-term results of ACL repair were related to a series of factors such as improper selection of indications and complications of knee arthrotomy.Up to now,arthroscopic ACL repair for acute ACL proximal rupture has achieved satisfactory effect in the short and middle term follow-up.However,relevant studies only derived from few sports medicine centers abroad.These studies exist the following problems: technical methods are not unified,most therapeutic methods have high technical requirements and are difficult to be widespread used,most of the operations take a long time and are expensive.The clinic needs a concise operation that is easy to be mastered and can achieve a stable therapeutic effect.Therefore,this study aims to introduce a primary repair technique for acute ACL rupture with less trauma,shorter operation time and no additional injury,and to evaluate its clinical efficacy.Tissue engineering and biotherapy were also widely used in ACL injury in recent years.Platelet-rich plasma(PRP)as a blood product rich in a variety of growth factors,has been used to promote the healing process after ACL injury.However,there has been no reports on intra-articular injection of PRP for primary repair after ACL rupture.Therefore,through histological studies of rabbits,we explored the effect of PRP on ligament healing after ACL primary repair,at the same time verified its effect on proprioceptors and knee OA.In addition,the histological effects of primary repair on the ACL remnant have not been reported,relevant studies will be carried out simultaneously in animal experiment.Methods:1.Patients with acute ACL rupture were included in this prospective trial and divided into two groups.The repair group was treated with ACL primary repair(nonabsorbable sutures run through the residual tissue of the ACL and were fixed to the femoral insertion using pushlock anchors)while patients in the reconstruction group underwent single-bundle anatomical reconstruction of ACL with autologous graft.Inclusion criteria: ACL proximal avulsion with favourable residual tissue,bone epiphysis has closed and less than 50 years old,time from injury to surgery was less than 3 weeks,unilateral knee injury.Subjective and objective functional evaluations were performed for every patient before surgery and 3,6,12 postoperative months to evaluate the difference in efficacy between the two groups Which includes IKDC subjective score,lysholm score,Kneelax3 measurement,Pivot shift test and Lachman test.Threshold to detection of passive motion(TTDPM)and joint position reproduction(JPR)were used to evaluate the proprioceptive function of the knee.2.Forty-eight experimental rabbits were randomly divided into 4 groups.Blank control group with no treatment,control group just cut off the ACL,repair group had the ACL cut off and were treated with primary repair,repair + PRP group was the same as repair group except using PRP postoperative.Four weeks postoperative,the control group and repair group were given intra-articular injection of 0.3 ml 0.9 % normal saline,once a week for 3 consecutive times.The repair + PRP group was injected with autologous PRP 0.3 ml,once a week for a total of 3 times.The experimental rabbits were then sacrificed at 8 and 12 weeks postoperative,the general healing of the ligament was observed,and the femoral-ligament-tibial complexes were obtained for the following experiments.3.HE staining was used to observe the cytomorphology of the ACL and tendon-bone healing site in each group.According to HE staining and toluidine blue staining,Mankin score was used to evaluate the knee articular cartilage condition in each group.4.Immunohistochemistry was used to detect the expression of CD34 and S100 in ACL,COLⅠin tendon-bone healing site and COLⅡin articular cartilage of the knee joint for each group.The m RNA expressions of COLⅠ,CD34 in tendon-bone healing site and COLⅡ in articular cartilage were detected by q PCR.The contents of COLⅠin tendon-bone healing site and COL Ⅱ in articular cartilage were detected by Western blotting for each group.Results:1.The data of 38 patients with acute proximal ACL rupture were finally obtained,with 19 cases in each group.There were no significant difference in Lysholm scores,IKDC subjective scores and kneelax3 measurements(side to side different,SSD)between the two groups at every time point postoperative.There were no significant difference in the positive rates of Lachman test and Pivot-shift test between the two groups at different follow-up periods.At 3 or 6 postoperative months,the repair group had better results in TTDPM and JPR values compared with the reconstruction group.At12 months postoperative,there were no significant difference in TTDPM and JPR values between the two groups.2.Eight weeks postoperative,HE staining of ACL tissue sections in control group displayed tissue disintegration,collagen fiber absorption,cell shrinkage,and nuclear abnormality.In the repair group,ACL tissue has been well preserved,the number and morphology of cells were similar to the blank control group.In the repair + PRP group,the collagen tissues were obviously dense,with regular arrangement,the number of cells was greater and the morphology of cells was full.At 12 weeks postoperative,the ligament remnant in the control group was completely absorbed.In the repair group,collagen tissue regeneration was observed under microscope,the arrangement of collagen fibers was gradually tidy,and the number of cells increased compared with 8 weeks.The repair + PRP group was similar to normal ACL.3.In the blank control group,the tendon-bone healing site had a high cell density,the tissue was dense and the tide line was wide and uneven.In the repair group,the combination of ligament and bone can be seen at the healing site 8 weeks postoperative,but the tissue boundaries were obvious.At 12 weeks postoperative,the fusion of ligament and bone at the healing site became more compact,the tide line became wider,and it was seen that the tissues were intertwined penetration.The tide lines at the tendon-bone healing site in the repair + PRP group were slightly wider than the repair group at 8 weeks postoperative,and the ligament tissues at the tendon-bone healing site were more denser.The fusion state of the ligament and bone in the repair + PRP group was similar as blank control group at 12 weeks postoperative.4.At 12 weeks postoperative,the cartilage of the blank control group was smooth and flat,the cartilage layer was thick and uniform,and the chondrocytes were evenly distributed.In the control group,compared with the blank control group the cartilage was partially damaged,the number of chondrocytes was significantly reduced,some lacunae were empty,the cartilage matrix was lightly colored,and cells were clustered occasionally.The overall condition of the repair group was significantly better than the control group,but local roughness was still visible on the cartilage surface and the chondrocyte density was lower compared with the blank control group.However,the cartilage surface and chondrocytes in the repair + PRP group were close to the blank control group.Mankin scores of knee joints in each group showed that early OA manifestations had occurred in the control group 12 weeks postoperative,and the Mankin scores in the repair group were significantly lower than the control group,no obvious OA manifestations were found in the repair + PRP group.5.The results of Micro vessel density(MVD)showed the control group were significantly lower than the blank control group and the repair group at 8 weeks postoperative.There was no significant difference between the repair group and the blank control group at 8 weeks postoperative.At 8 and 12 weeks postoperative,the MVD values of the repair + PRP group increased compared with the repair group.The MVD values of the repair group and the repair + PRP group were significantly higher at 12 weeks than 8 weeks postoperative.6.In terms of proprioceptors,at 8 weeks postoperative,the number of proprioceptors in the other three groups decreased compared with the blank control group.The number of proprioceptors in the repair group was significantly higher than the control group.The number of proprioceptors in the repair + PRP group was also significantly higher compared with the repair group.At 12 weeks postoperative the number of proprioceptors in the repair + PRP group and the repair group was still reduced compared with the blank control group,and the number of proprioceptors in the repair + PRP group was still increased than repair group.The number of proprioceptors in both the repair + PRP group and the repair group increased significantly at 12 weeks compared with 8 weeks postoperative.7.The expressions of COL I and CD34 in the tendon-bone healing site at each time point postoperative were increased in the repair + PRP group compared with the repair group,and the expressions of COL I in the repair group and the repair + PRP group were decreased compared with the blank control group.The expression of CD34 in the repair group and repair + PRP group gradually increased,and were significantly higher than the blank control group at 12 weeks postoperative.At 12 weeks postoperative,in the control group the expression of COL II in cartilage tissue was significantly reduced compared with the repair group and the blank control group.However,the expression of COL II in the repair + PRP group was close to the blank control group.Conclusion:1.Clinical study has confirmed that under the premise of reasonable selection of indications,compared with ligament reconstruction,ACL primary repair can also achieve favorable joint stability in the early postoperative period.The knee joint proprioceptive function in the early postoperative period is better than ACL reconstruction.There is no difference in postoperative complication and reoperation rate between the two groups.Clinically,primary ACL repair can be a alternative treatment for some acute ACL rupture patients.2.After primary repair,ACL remnant with its native blood vessels and proprioceptors can be preserved.Intra-articular injection of PRP can promote ACL healing,promote the survival and regeneration of vascular structure and proprioceptor,and can reduce the severity of knee OA. |
PDF Full Text Request