Studies On Outcomes Of Anterior Cruciate Ligament Reconstruction With Remnant Preservation

Anterior cruciate ligament(ACL)injury is a common sports injury of the knee joint.The arthroscopic ACL reconstruction has become a classic surgical procedure in the field of sports medicine in treating ACL injury.Although the mechanical stability of knee joints was relatively satisfactory,there were still a number of patients who showed an inferior histological healing status of the grafted tendons.Recently,an increasing number of articles have reported that thick and abundant ACL remnant could often be encountered during ACL reconstruction.Some authors thus considered that preserving the remnant of ACL during ACL reconstruction could improve both the histological healing status and the mechanical strength of the grafted tendons,therefore enhance the stability of knee joints.However,there still lacks of basic experimental studies or high-level clinical studies to prove the above hypothesis.In our basic experimental study,a complete ACL femoral detachment model was first created in New Zealand rabbits.The animals were randomly allocated into the remnant-preserving and remnant-sacrificing ACL reconstruction group.The survival rate of ACL remnant,the histological healing status and the mechanical strength of the grafted tendons were then evaluated post-operatively by macroscopic evaluations,histological staining,and tensile tests,respectively.Results showed that:(1)in the remnant-preserving ACL reconstruction group,the survival rate of ACL remnants was only 60%;(2)No significant differences could be detected in neither the histological healing status(number of the vascular endothelial growth factors and the neurofilaments found in immunofluorescent staining)nor the mechanical strength(load to failure,elongation at failure,and modulus of elasticity calculated in the tensile tests)of the grafted tendons between the two groups.In our clinical study,93 eligible patients suffered from ACL injuries were randomly allocated into the remnant-preserving(n = 48)and the remnant-sacrificing(n = 45)ACL reconstruction group from January 2010 to October 2012.The post-operative assessments including the knee functional scales,the stability examinations,the proprioceptive evaluations,and the second-look arthroscopy were performed at a minimum 2-year follow-up time,respectively.Finally,there were 82(88.2%,82/93)patients completed the follow-up tasks,with 42 in the remnant-preserving ACL reconstruction group and 40 in the remnant-sacrificing ACL reconstruction group.Results showed that there were no significant differences between the two groups in terms of the knee functional scales(International Knee Documentation Committee,IKDC objective classifications;Lysholm subjective scores),the stability examinations(Lachman tests;pivot-shift tests;KT-1000 side-to-side difference),the proprioceptive evaluations(side-to-side difference of joint position sense),and the second-look arthroscopy(synovial coverage classification of the grafted tendons).The results of basic experimental study and the clinical study both showed that neither the histological healing status nor the mechanical strength of the grafted tendons,as well as the stability of knee joints could be improved by remnant-preserving ACL reconstruction compared with remnant-sacrificing ACL reconstruction.Therefore,the superiorities of remnant-preserving ACL reconstruction could not be confirmed from the current findings of our study.