CORR insights?: Mesenchymal stem cells in synovial fluid increase after meniscus injury

摘要

Where Are We Now? In the era of joint preservation surgery and orthobiologic treatments, the meniscus plays a pivotal role in the management of knee disorders. This is in contrast with the early years of orthopaedic surgery when the menisci were considered as "functionless remnants of leg muscle origin" [1], and consequently, entirely excised if injured. This paradigm shift reflected the increased understanding of the meniscus function that has been gained through the years, and is now widely recognized by the orthopaedic community. However, controversy still exists regarding both the indications for surgery and the optimal reparative/ regenerative treatments for meniscal tears. Briefly, lesions occurring in the vascular zone of young patients typically are repaired with one of the various suturing techniques currently available, usually with good clinical results. While many orthopaedic surgeons see benefit in restoring meniscus anatomy also in the avascular zone, it is important to recognize that spontaneous healing can occur, and therefore some meniscal lesions can be treated nonopera-tively with success. An interesting rationale to these approaches is provided by the work of Matsukura et.al., which demonstrates an increase in mesenchymal stem cells (MSCs), possibly derived from the synovium, in the synovial fluid after meniscus injury. This study follows a notable series of experimental studies on synovial MSCs by these authors, and is particularly valuable since it has been performed in human patients with a healthy control group.