Ren, Ye

Abstract: In knee arthroscopy procedures, maintaining the opening of the medial compartment requires an assistant. Creating the posterior portal in knee arthroscopy is also a challenge because of the shape changes of the thick muscle. The leg is usually placed on the surgical bed, is angled off the lateral aspect of the bed, or drapes over the surgical bed in which the leg plates are removed. However, the aforementioned positions have some limits because of surgical convenience and procedural stability. In this Technical Note, we propose an approach to improve the existing knee positions using a metal round stool as a foot support. The method aims to reduce reliance on human assistants during knee arthroscopy procedures and restore the natural positioning of leg muscles, potentially improving procedural outcomes. Technique Video video See video under supplementary data.

AbstractChordae tendineae, referred to as heart tendinous cords, act as tendons connecting the papillary muscles to the valves in the heart. Their role is analogous to tendons in the musculoskeletal system. Despite being exposed to millions of cyclic tensile stretches over a human's lifetime, chordae tendineae rarely suffer from overuse injuries. On the other hand, musculoskeletal tendinopathy is very common and remains challenging in clinical treatment. The objective of this study was to investigate the mechanism behind the remarkable durability and resistance to overuse injuries of chordae tendineae, as well as to explore their effects on flexor tenocyte biology. The messenger RNA expression profiles of chordae tendineae were analyzed using RNA sequencing and verified by quantitative reverse transcription polymerase chain reaction and immunohistochemistry. Interestingly, we found that periostin (Postn) and fibroblast growth factor 7 (FGF7) were expressed at significantly higher levels in chordae tendineae, compared to flexor tendons. We further treated flexor tenocytes in vitro with periostin and FGF7 to examine their effects on the proliferation, migration, apoptosis, and tendon‐related gene expression of flexor tenocytes. The results displayed enhanced cell proliferation ability at an early stage and an antiapoptotic effect on tenocytes, while treated with periostin and/or FGF7 proteins. Furthermore, there was a trend of promoted tenocyte migration capability. These findings indicated that Postn and FGF7 may represent novel cytokines to target flexor tendon healing. Clinical significance: The preliminary discovery leads to a novel idea for treating tendinopathy in the musculoskeletal system using specific molecules identified from chordae tendineae.