Background: Ankle sprains are one of the most common injuries in athletic populations. Misdiagnosed and untreated ankle sprains will cause chronic ankle instability (CAI), which can significantly affect the performance of athletes. This study aimed to investigate the prevalence and characteristics of CAI in elite athletes of different sports. Method: This cross-sectional study included 198 elite athletes from Guangdong provincial sports teams. All participants answered a questionnaire about ankle sprains and ankle instability. The severity of their ankle instability was evaluated by the Cumberland Ankle Instability Tool (CAIT). Participants further underwent clinical examinations from sports medicine doctors to determine the presence and characteristics of ankle instability. The datasets were analyzed to determine the differences in prevalence between age, gender, sports teams, and sports categories. Results: In 198 athletes, 39.4% (n = 78) had bilateral CAI while 25.3% (n = 50) had unilateral CAI. Female athletes had a higher prevalence of CAI than male athletes in the study (p = 0.01). Prevalence showed differences between sports categories, and were significantly higher in acrobatic athletes than non-contact athletes (p = 0.03). Conclusions: CAI was highly prevalent among elite athletes in this study, with female athletes and athletes in acrobatic sports being associated with a higher risk of developing CAI in their professional careers. Therefore, extra precautions need to be taken into account when applying ankle protections for these athletes.

This study aimed to explore whether the defect of visual function is a risk factor of knee anterior cruciate ligament (ACL) sports injury and to provide a theoretical basis for the primary prevention of ACL sports injury. This cross-sectional study included 392 participants divided into two groups: the sports injury group (287 with sports injury of knee) and the control group (105 healthy volunteers). Participants in the sports injury group were further divided into the ACL-Intact group (133) and the ACL-Deficient group (154). Participants in the sports injury group received a questionnaire about the conditions of their injury (including injury action, site condition, weather, contact) and a visual examination by synoptophore (including binocular vision, subjective and objective oblique angle, visual fusion range, stereoacuity). Participants in the control group only received the visual examination. In the end, we found that low visual fusion range (p = 0.003) and injury action, especially quick turn (p = 0.001), sudden stop (p < 0.001) and jump (p = 0.001), are the major risk factors for ACL injury in the analysis of the integrated data. In addition, athletes with low vision fusion range have increased risk of ACL sports injury when they make a sudden stop on wooden floor, plastic floor or cement floor on cloudy days (OR = 13.208). Visual factors, especially low fusion range, significantly increase the risk of ACL sports injury.

The meniscus is an important cushioning structure of the knee joint, with the maintenance of its normal structure and function playing a crucial role in protecting the joint from early degeneration. Stem/progenitor cells could be the key to help researchers to have a deeper understanding of the biological process of meniscal injury repair and may be important in the meniscus tissue regeneration processes. To the best of our knowledge, there is currently a lack of comprehensive reviews on existing research about the meniscus progenitor cells (MPCs). By reviewing the existing MPC literature, we aim to provide insights for future research on meniscus regeneration. The isolation methods, biological characteristics and the translational application of MPCs were summarized. MPCs could be isolated according to their colony-forming ability, marker expression, migration ability, and differential adhesion to fibronectin. Most existing studies on surface markers of MPCs have largely followed the paradigm of mesenchymal stromal/stem cell research. Based on the information provided by their surface markers and expression profile, researchers located MPCs in the peripheral surface area of the meniscus. Few researches have investigated the translation and application of MPCs, with most studies being limited to MPCs extraction and subsequent reimplantation in vivo. MPCs are a group of meniscus-resident cells, which exhibit certain stem/progenitor cell characteristics, such as the ability to undergo multilineage differentiation in in vitro culture.

The meniscus plays a crucial role in knee joint function, yet its limited intrinsic regenerative capacity, particularly within the avascular region, makes meniscal injuries a major therapeutic challenge. Meniscus progenitor cells (MPCs) have shown potential to promote meniscal regeneration, but their efficacy may be compromised in the inflammatory microenvironment. Joint lavage, a simple and clinically applied procedure that reduces intra-articular inflammation, may enhance the outcomes of cell-based therapies. Here, we investigated the therapeutic efficacy of combining joint lavage with MPC transplantation in rat partial meniscectomy models and further examined the effects of interleukin-1β (IL-1β), a key inflammatory mediator, on MPC function in vitro . Lavage significantly reduced intra-articular levels of multiple inflammatory cytokines, including IL-1β, which otherwise impaired MPC migration, proliferation, chondrogenic differentiation, and gene expression. In vivo , combined lavage and MPC therapy promoted more complete meniscal regeneration, enhanced type II collagen deposition, preserved cartilage integrity, and improved biomechanical properties compared with either treatment alone. These findings demonstrate that preconditioning the joint microenvironment through lavage markedly augments the regenerative potential of MPCs, providing a simple, low-cost, and clinically feasible strategy to improve meniscus and cartilage repair under inflammatory conditions.

Background The surgical treatment of meniscus injury has represented a clinical challenge for decades. Stimulating meniscus regeneration using transplanted meniscal progenitor cells has been suggested as a promising new strategy. However, there is a lack of studies which decisively identify and characterise progenitor cell populations in human meniscus tissues. Methods In this study, donor-matched progenitor cells were isolated via selective fibronectin adhesion from the avascular (PAvas) and vascular (PVas) regions of the meniscus and chondroprogenitors (PChs) from articular cartilage (n=5 donors). In addition, whole mixed populations of cells (MAvas, MVas, MChs) from the same regions were obtained by standard isolation techniques for comparison. The colony formation efficacy of PAvas, PVas and PChs was monitored using Cell-IQ® live cell imaging. Proliferation rates of progenitors were compared with their mixed population counterparts. Cell surface markers indicative of mesenchymal stromal cells (MSCs) profile and progenitor markers were characterised by flow cytometry in all populations. The chondrogenic capacity was assessed via pellet culture assays and measuring chondrogenic gene expression levels, GAG/DNA content and morphology. Results All meniscal progenitor and chondroprogenitor populations showed colony forming capacity in monolayer culture, whereas mixed populations were distributed randomly at passage 0. PVas had significantly lower population doubling times compare to MVas and proliferated faster than PAvas and PChs based on colony forming efficacy. Progenitor populations showed significantly higher positivity for CD49b and CD49c compared to their mixed population counterparts and PChs had a higher positivity level of CD166 compared to mixed chondrocytes. Collagen types II and X expression was significantly downregulated in pellets formed by progenitor populations. GAG/DNA analysis demonstrated that progenitor cells generally produced more GAG than mixed populations. Conclusions Our study demonstrates that the human meniscus contains meniscal progenitor populations in both the avascular and vascular regions. Meniscal progenitors derived from the vascular region exhibit enhanced proliferative and chondrogenic characteristics compared to those from the avascular region; this may associate with the enhanced meniscal healing potential in the vascular region. These findings build on the body of evidence which suggests that meniscal progenitors represent an attractive cell therapy strategy for meniscal regeneration.