Biomechanical evaluation of augmented and nonaugmented primary repair of the anterior cruciate ligament: an in vivo animal study

Abstract

Purpose The purpose of this study was to evaluate in a sheep model the biomechanical performance of augmented and nonaugmented primary repair of the anterior cruciate ligament (ACL) following transection at the femoral end during a 12-month postoperative observation. Methods Forty sheep were randomly assigned to nonaugmented or augmented primary ACL repair using a polyethylene terephthalate (PET) band. At two, six, 16, 26 and 52 weeks postoperatively four sheep in each group were sacrificed and biomechanical testing performed. Results Compared with nonaugmented primary ACL repair, the PET-augmented repair demonstrated superior biomechanical results from 16 weeks postoperatively onwards in terms of anterioposterior (AP) laxity, tensile strength and ligament stiffness. The augmentation device works as a stress shield during the ligament healing process. The nonaugmented ACL repair also resulted in ligament healing, but the biomechanical properties were at a significantly lower level. Conclusion These results support the previously reported histological findings following augmented primary ACL repair. This animal study on the healing capacity of the ACL may provide some important contributions to how primary healing in certain types of ruptures can be achieved.

Primary Repair of the Anterior Cruciate Ligament: A Systematic Review

“…Histologically, the augmented group showed more granulation tissue at 2 weeks, increased vascularity at 6 weeks, more fibroblasts and collagen at 16 weeks, more normalappearing collagen alignment at 26 weeks, and welldefined longitudinally oriented collagen fascicles with sparse cellularity at 52 weeks. In their follow-up study using the same model, Seitz et al 24 PRIMARY REPAIR OF ACL alone. They found that beginning at the 16-week time point, the PET-augmented primary repair group showed less instrumented laxity and greater tensile strength and ligament stiffness than the group that underwent suture repair alone (P < .05).…”

Anterior Cruciate Ligament: 3-D Fiber Anatomy, Fluorescence Arthroscopy & Healing

“…Next to ACL healing studies that transect the ACL in its midsubstance there are studies that transect the ACL at its Chapter 10 femoral insertion site. (121,134) The results of these studies demonstrate that the ACL has also a healing response at the femoral insertion site.…”

“…Một dụng cụ cố định động bên trong gân (DIS) đã được phát triển nhằm buộc hai đầu Dây Chằng Chéo Trước đứt trong khi giữ gối trong tư thế chuyển dịch ra sau cố định. (121,134).…”

Low revision rate and excellent subjective outcome of primary ACL repair with a minimum follow-up of 5 years

“…The clinical results achieved by ACL reconstruction are generally accepted. Nevertheless evident problems are well known, such as graft failure, donor site morbidity, loss of proprioception and the inexact anatomical form of reconstruction 6,7 . In addition, despite subjective and objective joint stability following reconstruction, the risk for posttraumatic arthritis remains [8][9][10] .…”

“…Only recently, primary ACL repair has regained increasing research interest. A number of preclinical studies demonstrated the potential role of primary repair in combination with modern surgical techniques and enhancing bioactive materials 7,[11][12][13] . Taylor et al mentioned that despite the reported unacceptable high failure rates of previously published clinical studies, there constantly was a subset of patients that met the criteria for clinical success 14 .…”