Collagen scaffold supplementation does not improve the functional properties of the repaired anterior cruciate ligament

Abstract

Primary suture anterior cruciate ligament (ACL) repair was abandoned in favor of reconstruction due to a high rate of clinical failures. However, the insertion of a collagen scaffold loaded with platelets into the wound at the time of suture repair (''enhanced primary repair'') has been shown to improve functional healing in animal models. Our objectives were to determine if using a collagen scaffold alone (without platelets) would be sufficient to increase the structural properties of the repaired ACL and decrease postoperative knee laxity compared to suture repair without the scaffold. Eight Yucatan minipigs underwent bilateral ACL transection and suture repair. In one knee, the repair was augmented with a collagen scaffold (SCAFFOLD group) while the other had suture alone (SUTURE group). After 13 weeks of healing, knee joint laxity and the structural properties of the ACL were measured. The addition of the collagen scaffold to suture repair of a transected ACL did not significantly improve the mean anteroposterior knee laxity [SCAFFOLD vs. SUTURE: 6.1 AE 1.4 vs. 4.4 AE 2.0 mm (p ¼ 0.07), 8.1 AE 2.0 vs. 7.6 AE 2.0 mm (p ¼ 0.66), and 6.2 AE 1.2 vs. 6.1 AE 1.8 mm (p ¼ 0.85) at 308, 608, and 908 flexion, respectively]. Likewise, there were no significant differences in the structural properties [SCAFFOLD vs. SUTURE: 367 AE 185.9 vs. 322 AE 122.0N (p ¼ 0.66) and 90.7 AE 29.5 vs. 85.0 AE 30.3N/mm (p ¼ 0.74) for the yield load and linear stiffness, respectively]. The use of a collagen scaffold alone to enhance suture repair of the ACL was ineffective in this animal model. Future work will be directed at stimulating biological activity in the scaffold. ß

Healing of the Goat Anterior Cruciate Ligament After a New Suture Repair Technique and Bioscaffold Treatment

“…Fisher et al found a 302% increase with the same AP load, and Fleming, Murray et al, found a 350% increase in ATT with a 35 N anterior tibial load. 40,41 In terms of stiffnesses of the healing ACL, these were, respectively, 23% in our study, 42% for Fisher et al, and 25% for Fleming, Murray et al Besides similarities, there are also differences between these studies. For example, the other studies used a mechanical augmentation, where the current study was relying only on the locking suture technique with absorbable sutures.…”

The Effect of Skeletal Maturity on Functional Healing of the Anterior Cruciate Ligament

“…In this study, an additional group of agematched knees with intact anterior cruciate ligaments was also tested to improve our ability to compare the results of this study with those in other studies of anterior cruciate ligament treatment in large animal models. For example, the graft strength at three months in a Yorkshire pig model was previously reported at 28% 27 . This suggests the values obtained in the present study for enhanced suture repair in the juvenile and adolescent groups compare favorably in a similar model.…”

“…In addition, the only repair type attempted in this study was suture repair with a collagen-platelet composite to enhance the repair. In prior studies, we looked at using suture repair alone for anterior cruciate ligament healing in the adolescent Yucatan porcine model 27 .…”

Biomechanical Outcomes of Bridge-enhanced Anterior Cruciate Ligament Repair Are Influenced by Sex in a Preclinical Model

“…For all knees, a Kessler suture using No. 1 Vicryl 1 was placed in the tibial stump of the ACL to repair the transected ligament [20,36,37]. Femoral (4.5 mm) and tibial (2.4 mm) tunnels were then drilled in standard positions for ACL reconstruction with the tibial tunnel exiting in the center of the tibial attachment and the femoral tunnel placed at the center of the femoral ACL attachment site.…”