The Lark-Loop Technique for Onlay Biceps Tenodesis: A Biomechanical, Histological, and Radiological Study in a Rabbit Model

Background: Arthroscopic cortical surface tenodesis has been established as an effective technique for managing lesions of the long head of the biceps tendon (LHBT). However, traditional suture techniques frequently provide insufficient initial mechanical strength, which may contribute to tenodesis failure. To address this limitation, the Lark-Loop suture technique was developed. Purpose: To compare the biomechanical, histological, and radiological outcomes of Lasso-Loop, Lark-Loop, and Krackow suture techniques for cortical surface tenodesis of the LHBT in a rabbit model. Study Design: Controlled laboratory study. Methods: A total of 75 New Zealand White rabbits underwent bilateral proximal biceps tenodesis using a cortical surface fixation model. Animals were randomly assigned to 1 of 3 groups: (1) Lasso-Loop suture (control group; n = 25), (2) Lark-Loop suture (experimental group; n = 25), and (3) Krackow suture (positive control group; n = 25). At 4, 8, and 12 weeks postoperatively, 21 rabbits from each group (n = 63 total) were sacrificed for evaluation: 3 rabbits per group were used for magnetic resonance imaging and histological analysis, and 4 rabbits per group for micro–computed tomography and biomechanical testing. An additional 12 rabbits (4 per group) were used for initial biomechanical testing at week 0. One-way analysis of variance and Bonferroni post hoc correction were used to assess between-group differences. A P value <.05 was considered statistically significant. Results: Macroscopically, complete healing at the tenodesis site was observed in all groups at 12 weeks. The Lark-Loop group demonstrated significantly improved signal-to-noise quotient values, mechanical strength, new bone formation, and histological tendon-bone integration compared with the Lasso-Loop group at all time points. No significant differences were observed between the Lark-Loop and Krackow groups. Conclusion: This study demonstrated that all 3 suture techniques achieved effective tendon-bone healing in a rabbit model. The Lark-Loop technique provided enhanced biomechanical properties and histological healing compared with the Lasso-Loop technique, and comparable outcomes to the Krackow stitch. Clinical Relevance: The findings suggest that the Lark-Loop technique may serve as a viable arthroscopic alternative for LHBT tenodesis in clinical practice, potentially enhancing tendon-bone healing and reducing failure rates.