Biomechanical Analysis of Lark‐Loop, Lasso‐Loop and Krackow Suture Technique in Tenodesis

Abstract

Objective Strong tendon grasping is vital to the success of a tenodesis operation. The purpose of this study was to evaluate the initial tendon‐fixation strength of the Lark‐Loop technique in arthroscopic suprapectoral biceps tenodesis and compare it with others commonly used techniques. Methods Thirty‐three porcine superficial flexor digitorum tendons were harvested from a local slaughterhouse and randomly divided into three groups to perform three tendon fixation techniques (Lasso‐Loop stich group, Lark‐Loop stich group or Krackow stich group; 11 tendons each group) with a No. 2 suture, respectively. Each tendon was pre‐tensioned in 5°N for 2 min and then cyclically loaded 5 to 30°N for 500 cycles to assess displacement. After cyclic loading, the tendon was loaded to ultimate tendon‐suture configuration failure at the rate of 1 mm/s. Finally, the mode of failure and the construct stiffness of the tendon were recorded and calculated. Results After cyclical loading, the displacement of the Lark‐Loop group was equivalent to the Krakow group (P > 0.9999) but significantly smaller than the Lasso‐Loop group (P = 0.0009). The ultimate load to failure for the Lark‐Loop was equivalent to the Krakow technique group (P = 0.1463) but significantly greater than the Lasso‐Loop group (P < 0.0001). The stiffness for the Lark‐Loop was equivalent to the Krakow group (P = 0.4718) but significantly greater than the Lasso‐Loop technique group (P < 0.0001). In the Lark‐Loop and Krackow group, all the tendons failed by suture breakage, while all the tendons failed by suture cutting through the tendon in the Lasso‐Loop technique group. Conclusion Lark‐Loop suture technique has biomechanical properties comparable to Krackow and superior to the Lasso‐Loop in terms of suture displacement, ultimate load to failure, and stiffness. Therefore, the Lark‐Loop suture fixation technique may be beneficial for arthroscopic biceps tenodesis.

Arthroscopic Suprapectoral Biceps Tenodesis Using Standard Portals

“…The use of a suture anchor and securing the tendon with a Krackow suture provides better pullout strength of the repair. 8 , 9 When compared to other methods of fixation, such as interference screws or bicortical buttons, suture anchors eliminate the need for internalization of the tendon in the bone. Placing a suture anchor into metaphyseal bone is associated with lower incidence of fracture, as compared to screws due to the larger size and cortical buttons in the diaphyseal bone, which may create a stress riser and subsequent increased risk of fracture.…”