Anatomic Knot Suture Anchor Versus Knotless Suture Anchor Technique for Anterior Talofibular Ligament Repair: A Biomechanical Comparison

Abstract

Background: To date, there are few biomechanical studies comparing the strength between knot repair and knotless repair procedures for anterior talofibular ligament (ATFL) injury. Purpose: To perform a biomechanical comparison of the strength of the arthroscopic ATFL repair technique with knot or knotless suture anchors in a cadaveric model with partial or complete ATFL injuries. Study Design: Controlled laboratory study. Methods: A total of 24 fresh-frozen cadaveric ankles were used. Arthroscopy was used to identify, section, and repair the ATFL on the fibular insertion site. The specimens were then randomly placed into 1 of 4 groups: group A received complete ATFL section and 1–suture anchor repair with knot, group B received complete ATFL section and 1-anchor knotless repair, group C received partial ATFL section and 1–suture anchor repair with knot, and group D received partial ATFL section and 1-anchor knotless repair. After repair, the ATFL tension was measured first with a digitalized tensiometer. Specimens were then mounted on a materials testing system to determine the ultimate load to failure and stiffness. Results: The mean ± SD ligament tension measured during the arthroscopic procedure was 8.6 ± 0.6 N for group A, 9.2 ± 0.5 N for group B, 9.4 ± 1.1 N for group C, and 9.6 ± 0.9 N for group D. No significant difference in tension was detected among groups. In load-to-failure testing, the mean ultimate failure load was 27.9 ± 4.1 N for group A, 26.2 ± 9.3 N for group B, 81.9 ± 26.5 N for group C, and 88.1 ± 41.6 N for group D. The mean ultimate failure loads of the partial repair groups were significantly higher than those of the complete repair groups (C vs A, P = .008; D vs B, P = .002), while there was no significant difference between groups A and B ( P > .05) or between groups C and D ( P > .05). Conclusion: The results of the present study showed that there was no significant difference in biomechanical properties between knot repair and knotless repair techniques. Clinical Relevance: Biomechanically, the results showed that knot suture anchor and knotless suture repair provide similar biomechanical strength for ATFL injury. Unfortunately, these methods in the complete ATFL section models provided less than half the strength and stiffness in the partial ATFL section models at time zero after surgery. As a result, 1–suture anchor repair is not suitable for complete ATFL injury regardless of the repair method.

Single Knotless Suture Anchor Repair of Anterior Talofibular Ligament Following Distal Fibula Nonunion Excision

“…Although there is concern regarding the strength of single knotless suture anchor repairs, a biomechanical study indicated an equivalent biomechanical strength between the knotless and knotted repair of ATFL injury. 34 Another biomechanical study reported that the single suture anchor repair at the distal fibular yields comparable strength and stiffness to that of the suture-only Broström repair. 35 In essence, the advantages of using a single knotless suture anchor outweigh any theoretical risks of this repair technique.…”

Arthroscopic Single Portal, Single Anchor Knotless Subscapularis Repair with Concomitant Tenodesis of the Long Head of the Biceps Tendon

“…Although the long-term outcomes of knot versus knotless suture anchors for this type of repair is unknown, the use of knotless sutures has shown equal or greater biomechanical strength for various orthopaedic pathologies. 17 , 18 Furthermore, knotless suture anchors reduce complications including patient discomfort, knot loosening, or knot migration. 17 Another advantage of this technique is the use of a single portal for both repairs instead of creating an additional portal for biceps tenodesis or transitioning to an open tenodesis.…”

“… 17 , 18 Furthermore, knotless suture anchors reduce complications including patient discomfort, knot loosening, or knot migration. 17 Another advantage of this technique is the use of a single portal for both repairs instead of creating an additional portal for biceps tenodesis or transitioning to an open tenodesis. This method overall reduces the risk of neurovascular injury, the risk of infection, and the recovery time for the patient.…”

Single-Portal, Single-Anchor Repair of a Superior Third Subscapularis Tear Using a Self-Punching Knotless Soft Suture Anchor

“… 42 , 44 Knotless suture anchors have also shown decreased variability in biomechanical properties and greater than or equal to biomechanical strength vs traditional suture anchors, offering a more consistent biomechanical outcome compared to knot repair. 45 , 46 Furthermore, given the variety and complexity of repairs with excellent outcomes, the technique presented in this note reduces steps, tools, implants, and time to perform the repair, while offering a similar high-quality repair. For instance, this technique simultaneously passes sutures through the tendon and places the anchor into the lesser tuberosity, eliminating the use of traditional suture passers that are typically needed to pass sutures through the tendon.…”

“… 36 The use of a knotless suture anchor reduces complications associated with patient discomfort, knot migration, knot impingement, and chondral abrasion. 45 , 47 , 48 This surgical technique effectively reduces difficulties associated with traditional suture anchors and knot repairs, offers strong fixation and biomechanical performance, and minimizes both operative time and potential postoperative complications.…”