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.

IntroductionSuprapectoral tenodesis is a common technique for the treatment of long head biceps tendon lesions. However, so far, there is no gold standard treatment in all-inside arthroscopy. The purpose of the present study was to introduce and evaluate the functional outcomes of an innovative, all-inside arthroscopic high resistance loop (H-loop, high resistance to tissue cutout and 360° grasping of the tendon) technique for long head of biceps (LHB) tenodesis.MethodFrom September 2020 to March 2022, a series of cases of 32 consecutive patients (28 rotator cuff tear with LHBT pathology and 4 superior labrum anterior-posterior (SLAP) tears which including 2 type II and 2 type IV) who received LHB tenodesis using all-inside arthroscopic high resistance loop technique were included in this study. The American Shoulder and Elbow Surgeon Score (ASES), Visual Analog Scale (VAS), Simple Shoulder Test Score (SST), Constant–Murley scores, and University of California at Los Angeles Scoring System (UCLA) were used to evaluate the clinical outcomes of patients in preoperative and final follow-up. Meanwhile, postoperative complications were also observed.Result32 patients (14 women and 18 men, average age was 55.7 years) underwent all-inside arthroscopic knotless suprapectoral biceps tenodesis using the H-Loop stitch technique. The mean time of follow-up was 16.2 ± 2.6 months. The ASES, VAS, Constant–Murley, SST, and UCLA scores improved from 51.5 ± 15.8, 5.5 ± 1.6, 57.8 ± 14.7, 5.0 ± 2.8, and 16.1 ± 3.8 preoperatively, to 89.1 ± 7.5, 1.0 ± 0.8, 87.3 ± 5.5, 10.4 ± 1.5, and 31.3 ± 2.6 in the last follow-up, respectively (p &lt; 0.001). During the follow-up, no patients in this study experienced postoperative complications such as infection of the wound, injury of nerves, and hardware failure; no patients required revision after their operation. In addition, none of the patients had cramping or a “Popeye” deformity during follow-up.ConclusionThis article presents an innovative, all-arthroscopic H-loop technique for LHB tenodesis. This technique for LHB tenodesis showed favorable functional and cosmetic outcomes, as well as high satisfaction rates. Due to its simplicity of operation and satisfactory preliminary clinical outcomes, H-loop technique is perhaps another option to choose in all-inside arthroscopic LHB tenodesis.

Frozen shoulder (FS) is characterized by pain and limited range of motion (ROM). Inflammation and fibrosis are accepted as main pathologic processes associated with the development of FS. However, the intrinsic mechanisms underlying pathologic fibrosis remain unclear. We aimed to elucidate the key molecules involved in pathologic fibrosis and explore new therapeutic targets for FS. Synovial fibroblasts isolated from patient biopsies were identified using immunofluorescence. Western blotting, RT-qPCR, cell adhesion tests, and would-healing assays were used to evaluate the fibrosis-related functions of synovial fibroblasts. Elevated cluster of differentiation 36 (CD36) expression was detected in FS using Western blotting and immunohistochemistry. Salvianolic acid b (SaB) inhibited CD36, blocking synovial fibroblast-induced inflammation and fibrosis. Our RNA-seq data showed that knocking down CD36 dramatically impaired the capacity of synovial fibroblasts for cell adhesion and that the PI3K-Akt signaling pathway may be crucial to the fibrotic process of FS. By up-regulating CD36 and inhibiting the phosphorylation of Akt, we demonstrated that CD36 promotes pathologic fibrosis by activating the PI3k-Akt pathway. Finally, rats treated with SaB had improved ROM and less collagen fiber deposition than the FS model group.Conclusion: SaB attenuates inflammation and inhibited the CD36-mediated activation of the PI3K-Akt signaling pathway to block pathologic fibrosis of FS in vitro and in vivo models.