Effects Of Injury Capsule Combined With Platelet-Rich Plasma On Tendon Bone Healing After Anterior Cruciate Ligament Reconstruction In Rabbits

Objective: This study aims to investigate the effects of injury capsule combined with platelet-rich plasma(PRP)on tendon bone healing(including tendon bone interface fibroblasts,chondrocytes,collagen fibers,and biomechanics)after anterior cruciate ligament(ACL)reconstruction in New Zealand rabbits,as well as its effects on tendon bone healing at different stages,so as to guide the clinical practice of better combination medication after ACL reconstruction,To provide evidence for traditional Chinese medicine to promote tendon bone healing at different stages.Methods: 48 healthy New Zealand white rabbits were selected to establish an ACL reconstruction model of the right lower limb and randomly divided into 4 groups: blank control group,injury capsule group,PRP intraarticular injection group,PRP intraarticular injection+injury capsule group,with 12 rabbits in each group.After surgery,four rabbits were given physiological saline,injured capsule gavage,PRP injection,and injured capsule gavage combined with PRP injection for intervention.Four rabbits were killed at week 4,week 8,and week 12,respectively,and the femoral ligament tibial complex(FATC)was removed.Histologically,hematoxylin eosin staining H-E staining and Masson’s Trichrome staining were used to observe the growth of various cells and changes in the proliferation,arrangement,and distribution of collagen fibers during tendon bone healing;Biomechanical specimens were selected for the ultimate tensile load test to observe the ultimate tensile strength of the reconstructed ligament when completely ruptured.Finally,a statistical analysis was performed for comparison between groups.Results: At the 4th,8th,and 12 th weeks,the injured capsule group,PRP group,and injured capsule+PRP group were superior to the blank control group in terms of the appearance of ligaments,synovial membrane coverage,tension,and closure of the ostium,while the injured capsule+PRP group was the best.At the 4th and 8th weeks,the PRP group was superior to the injured capsule group,while at the 12 th week,the injured capsule group was superior to the PRP group,and the blank control group was the worst;In terms of H-E staining and Masson trichrome staining,at the 4th and 8th weeks,the growth,collagen fiber proliferation,and arrangement and distribution of various cells at the tendon bone healing site in the injury capsule group,PRP group,and injury capsule+PRP group were better than those in the blank control group,and the injury capsule+PRP group was the best.At the 8th week,the PRP group was better than the injury capsule group;At the 12 th week,the injury capsule group was superior to the PRP group;Statistical analysis showed that the ultimate tensile load at the 4th,8th,and12 th weeks was statistically significant(P<0.05),with the injury capsule+PRP group being the best and the blank control group the worst;At week 4,the PRP group was superior to the injured capsule group,with a statistically significant difference(P<0.05).At week 8,although the PRP group was superior to the injured capsule group,there was no statistically significant difference(P=0.12>0.05).At week 12,the injured capsule was superior to the PRP group,with a statistically significant difference(P<0.05).Conclusion: The combination of intragastric administration of injury capsule and intraarticular injection of PRP can actively promote tendon bone healing after anterior cruciate ligament surgery in rabbits,improve the strength of the graft,promote its mechanical function,and have a better effect than the use of both alone.