Biomechanical assessment of lateral ulnar collateral ligament repair and reconstruction with or without internal brace augmentation

Craig Melbourne; James L Cook; Gregory J Della Rocca; Christopher Loftis; John Konicek; Matthew J Smith

doi:10.1016/j.jseint.2020.01.011

Biomechanical assessment of lateral ulnar collateral ligament repair and reconstruction with or without internal brace augmentation

JSES Int. 2020 May 4;4(2):224-230. doi: 10.1016/j.jseint.2020.01.011. eCollection 2020 Jun.

Authors

Craig Melbourne¹, James L Cook¹, Gregory J Della Rocca¹, Christopher Loftis¹, John Konicek², Matthew J Smith¹

Affiliations

¹ Department of Orthopaedic Surgery, University of Missouri, Columbia, MO, USA.
² Department of Orthopedic Research, Arthrex, Inc., Naples FL, USA.

Abstract

Background: Surgical treatment of posterolateral rotatory instability (PLRI) using primary repair or reconstruction of the lateral collateral ligament complex have proven inconsistent. This study aimed to test the hypothesis that augmentation of LUCL repair or palmaris longus tendon reconstruction using a suture tape augmentation would be associated with less rotational displacement and greater torque load to failure (LTF) compared with nonaugmented constructs.

Methods: Cadaveric elbows (n = 12 matched pairs) were used. Baseline stiffness and displacement values were obtained. The LUCL was transected followed by repair alone, repair with augmentation, reconstruction with palmaris longus graft, or reconstruction with augmentation. Specimens were retested including torque LTF. Paired t tests were performed to assess the biomechanical effects of augmentation.

Results: Augmentation was associated with higher LTF than repair and reconstruction alone (P = .008 and .047, respectively). Displacement was less with augmentation in reconstruction groups (P = .048) but not in repair groups. Suture tape augmentation maintained rotational stiffness better than repair alone (P = .01). Although reconstruction with augmentation maintained rotational stiffness better than nonaugmented reconstruction, the differences were not statistically significant (P = .057). Mode of failure for repair alone was predominantly suture pulling through repaired ligament. Augmented repairs primarily failed at the anchor-bone interface. Modes of failure for both reconstruction groups were similar, including graft tearing and/or slipping at the anchor.

Conclusion: When positioned in neutral forearm rotation and 90^o of flexion to simulate postoperative conditions, augmentation of LUCL repair or tendon reconstruction using suture tape is associated with better resistance to rotational loads compared with nonaugmented repair or reconstruction, while maintaining near-native rotational stiffness.

Keywords: Elbow; internal brace; lateral ulnar collateral ligament; posterolateral rotatory instability; suture tape augmentation; tendon reconstruction.