The detached stump of the torn anterior cruciate ligament adheres to the femoral notch wall and then to the posterior cruciate ligament within 6 months from injury

Abstract

Purpose To evaluate the progressive changes in the morphology of traumatic ruptures of the anterior cruciate ligament (ACL) over time. A secondary objective was evaluating their correlation with meniscal tears or chondral lesions. Methods The study included one hundred and one patients who underwent ACL reconstruction surgery of the knee after a definite date of injury. The torn ACL remnant morphological pattern was assessed and classified during arthroscopy. A correlation analysis was performed between the pathological features of the remnant and the time length from injury. In addition, correlation between ACL remnant subtypes and meniscal tears or chondral lesions was evaluated. Results At surgery there were four distinct ACL tear morphological patterns that were correlated to the time span from injury (r = 0.61, p < 0.001) and ended with scarring of the femoral remnant to the posterior cruciate ligament. The early pattern was noticed within median time of 2.6 months from injury and appeared as a separate stump with no scar tissue. The following two patterns appeared within 6 months from injury and were characterized by adhesion of scar tissue to different locations in the femoral notch. The last morphological pattern appeared as adherence of the ACL stump to the posterior cruciate ligament. This pattern was seen in some patients within 6 months from injury but was the dominant pattern later on and was also correlated with meniscal tears. Conclusions During the first 3 months from injury the gross morphological features of the torn ACL remnant showed no scar. This phase was followed by scarring of the femoral remnant at first to the femoral notch, and eventually to the posterior cruciate ligament within 6 months from injury and later on. Therefore, further research on the healing potential of the human ACL stump and its biological environment should be focused on the first 3 months from injury. Study Design Case series; Level of evidence, 4.

Primary Repair for Treating Acute Proximal Anterior Cruciate Ligament Tears: A Histological Analysis and Prospective Clinical Trial

“…Our results show three key indications: the acute phase of history (no more than 2 months), proximal tears, and intact remnant tissue. If these indications are not met, they will eventually be reflected in the quality of the remnant, such as excessive absorption or insufficient tension to support primary repair ( Haviv et al, 2019 ). Although primary repair has a narrow range of indications, it can still bring considerable benefits to target patients compared with ACL reconstruction.…”

Clinical application of modified Crain classification in the Design of Anterior Cruciate Ligament Reconstruction with remnant preservation

“…In this study, for groups Ia and Ib ACL remnants, the remaining bundle can be completely preserved by single-bundle reconstruction with the remnant-preserving technique. The undamaged vascular and neural structures in the preserved bundle can accelerate the biological healing of the graft and the recovery of neuromuscular control [31][32][33]. Double-bundle reconstruction with the remnant-preserving technique can completely preserve the groups Ic, IIa, IIb, IIc ACL remnants, facilitating the healing of the graft and early reinnervation of nerve fibers [34].…”

The multiple ligament-injured knee: When is primary repair an option?

“…To date, however, it is unknown what the ideal timeframe for primary repair is, although the majority of published studies noted that primary repair was performed within two weeks from injury [56][57][58]. A recent case-control study found a cut-off of four weeks (OR 3.3, P b 0.001) for performing primary repair of ACL tears, indicating that surgery should be indeed performed in the acute setting when attempting primary repair [47], although some tears can also be repaired in the chronic setting when the ligament scars to the PCL and/or the tissue length and quality remains preserved [59,60]. It should be noted that surgery within two weeks is associated with postoperative stiffness [61], and it is therefore important that patients have improving range of motion and resolving irritation of the knee prior to surgery.…”