Bo Qin

Background: Split fractures of the humeral greater tuberosity (HGT) are common injuries. Although there are numerous surgical treatments for these fractures, no classification system combining clinical and biomechanical characteristics has been presented to guide the choice of fixation method. Methods: We created a standardised fracture of the HGT in 24 formalin-fixed cadavers. Six were left as single-fragment fractures (Group A), six were further prepared to create single-fragment with medium size full-thickness rotator cuff tear (FT-RCT) fractures (Group B), six were cut to create multi-fragment fractures (Group C), and six were cut to create multi-fragment with FT-RCT fractures (Group D). Each specimen was fixed with a shortened proximal humeral internal locking system (PHILOS) plate. The fixed fractures were subjected to load and load-to-failure tests and the differences between groups analysed. Results: The mean load-to-failure values were significantly different between groups (Group A, 446.83 ± 38.98 N; Group B, 384.17 ± 36.15 N; Group C, 317.17 ± 23.32 N and Group D, 266.83 ± 37.65 N, P < 0.05). The load-to-failure values for fractures with a greater tuberosity displacement of 10 mm were significantly different between each group (Group A, 194.00 ± 29.23 N; Group B, 157.00 ± 29.97 N; Group C, 109.00 ± 17.64 N and Group D, 79.67.83 ± 15.50 N; P < 0.05). These findings indicate that fractures with a displacement of 10 mm have different characteristics and should be considered separately from other HGT fractures when deciding surgical treatment. Conclusions: Biomechanical classification of split fractures of the HGT is a reliable method of categorising these fractures in order to decide surgical treatment. Our findings and proposed system will be a useful to guide the choice of surgical technique for the treatment of fractures of the HGT.

Background: Application of platelet-rich plasma (PRP) can improve tendon-bone healing (TBH) after rotator cuff surgical repair. Graphene Oxide (GO) is a steady, controlled, and sustained carrier. The purpose of this study is to determine whether GO/PRP Composite Scaffold enhances the TBH after RC surgical repair in a rabbit model.Methods: A full-thickness tear of the supraspinatus tendon was created and repaired in 36 adult male New Zealand rabbits. They were divided into three groups: Control group, PRP group, and GO/PRP Composite Scaffold group (GO group). The effect of GO/PRP Composite Scaffold on TBH was assessed using histological and biomechanical evaluations at 8 and 12 weeks postoperatively.Results: Histological analysis showed that greater continuity, better orientation, and more density of collagen fiber were detected in the GO group than PRP and Control groups at 8 and 12 weeks, respectively. Results of biomechanical evaluations showed that the load to failure and stiffness of the GO group were statistically higher than those of PRP and Control groups at both 8 and 12 weeks (P0.05), while the stiffness at 12 weeks was higher than that at 8 weeks (P Conclusions: These results demonstrated that GO/PRP Composite Scaffold enhanced the TBH following rotator cuff surgical repair in a rabbit model. The GO may be an effective carrier for PRP into repair sites.

Introduction. The acromion is a small section of the scapula which extends anteriorly from the spine of the scapula and the acromial angle (AA) is a prominent bony point at the junction of the lateral border of the acromion and the spine of the shoulder blade. As is well known, the morphology of the acromion and the acromial angle are important as their anatomical variation may contribute to shoulder pathologies. However, few people have studied the morphology and the association between the acromion and the acromial angle. The study explores the acromion and the acromial angle in the anatomical morphology and the association, providing an anatomical basis for clinical diagnosis and treatment. Material and Methods. A total of 292 dry, intact scapulae (152 right, 140 left) were used in the study. Three types of the acromion were already measured, type I(flat shape), type II (curved shape), and type III (hooked shape), respectively. Three types of the acromial angles were also measured in this study, C shape, L shape, and Double Angle shape. Results. The research result shows that C shape and L shape were the most common, while Double Angle shape was the least common. C shape was often related to type I (flat shape) and L shape was often related to type II (curved shape). Conclusions. The presented data provides precise and well-sorted information about the acromion and the acromial angle variation in Chinese population, contributing to diagnosis and treating in shoulder pathology.