Level II; systematic review of levels I and II studies.

Objective This study was performed to compare the clinical effects of locking plates (LPs) with those of hook plates (HPs) in the treatment of Neer type II distal clavicle fractures. Methods From August 2014 to April 2018, 64 patients with Neer type II distal clavicle fractures were treated in our department. The clinical effects were assessed with respect to the operation time, intraoperative blood loss, incision length, fracture healing, postoperative pain, postoperative complications, and postoperative shoulder joint function. Results There were no significant differences in the healing time, operation time, or intraoperative blood loss between the LP and HP groups. The incision length was significantly shorter in the LP than HP group, and the postoperative complication rate was significantly lower in the LP than HP group. The visual analog scale score, Constant–Murley score, and University of California Los Angeles score were significantly better in the LP than HP group. Conclusions Compared with HPs, the use of LPs involves a smaller incision in the treatment of Neer type II distal clavicle fractures and significantly reduces postoperative pain and complications. Therefore, priority can be given to the use of LPs in the treatment of Neer type II distal clavicle fractures.

Level I, systematic review of level I studies.

Bone is a frequent target of tumor metastasis, with high incidence rate and poor prognosis. Osteoclasts play a key role in the process of tumor bone metastasis. Interleukin-17A (IL-17A) is an inflammatory cytokine, highly expressed in a variety of tumor cells, that can alter the autophagic activity of other cells, thereby causing corresponding lesions. Previous studies have shown that low concentration IL-17A can promote osteoclastogenesis. The aim of this study was to clarify the mechanism of low concentration IL-17A promoting osteoclastogenesis by regulating autophagic activity. The results of our study showed that IL-17A could promote the differentiation of osteoclast precursors (OCPs) into osteoclasts in the presence of RANKL, and increase the mRNA levels of osteoclast-specific genes. Moreover, IL-17A increased the expression of Beclin1 by inhibiting the phosphorylation of ERK and mTOR, leading to enhanced autophagy of OCPs, accompanied by decreased OCP apoptosis. Furthermore, knockdown of Beclin1 and suppression of autophagy by 3-methyladenine (3-MA) significantly attenuated the enhanced osteoclastogenesis induced by IL-17A. In summary, these results indicate that low concentration IL-17A enhances the autophagic activity of OCPs through the ERK/mTOR/Beclin1 pathway during osteoclastogenesis, and further promotes osteoclast differentiation, suggesting that IL-17A may serve as a potential therapeutic target for cancer-related bone resorption in cancer patients.