Exercise remains a hallmark treatment for post-traumatic osteoarthritis (PTOA) and may maintain joint homeostasis in part by clearing inflammatory cytokines, cells, and particles. It remains largely unknown whether exercise-induced joint clearance can provide therapeutic relief of PTOA. In this study, we hypothesized that exercise could slow the progression of preclinical PTOA in part by enhancing knee joint clearance. Surgical medial meniscal transection was used to induce PTOA in 3-month-old male Lewis rats. A sham surgery was used as a control. Mild treadmill walking was introduced 3 weeks post-surgery and maintained to 6 weeks post-surgery. Gait and isometric muscle torque were measured at the study endpoint. Near-infrared imaging tracked how exercise altered lymphatic and venous knee joint clearance during discrete time points of PTOA progression. Exercise mitigated joint degradation associated with PTOA by preserving glycosaminoglycan content and reducing osteophyte volume (effect size (95% CI); 1.74 (0.71–2.26). PTOA increased hind step widths (0.57 (0.18–0.95) cm), but exercise corrected this gait dysfunction (0.54 (0.16–0.93) cm), potentially indicating pain relief. Venous, but not lymphatic, clearance was quicker 1-, 3-, and 6-weeks post-surgery compared to baseline. The mild treadmill walking protocol expedited lymphatic clearance rate in moderate PTOA (3.39 (0.20–6.59) hrs), suggesting exercise may play a critical role in restoring joint homeostasis. We conclude that mild exercise has the potential to slow disease progression in part by expediting joint clearance in moderate PTOA.

中文翻译：

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在雄性大鼠骨关节炎关节不稳定模型中，轻度运动可加速关节间隙并减缓关节退化


运动仍然是创伤后骨关节炎 (PTOA) 的标志性治疗方法，并且可以部分通过清除炎症细胞因子、细胞和颗粒来维持关节稳态。目前尚不清楚运动引起的关节间隙是否可以缓解 PTOA。在这项研究中，我们假设运动可以部分通过增强膝关节间隙来减缓临床前 PTOA 的进展。采用手术内侧半月板横断术在 3 个月大的雄性 Lewis 大鼠中诱导 PTOA。使用假手术作为对照。术后 3 周开始在跑步机上进行轻度步行，并维持至术后 6 周。在研究终点测量步态和等长肌肉扭矩。近红外成像追踪运动在 PTOA 进展的离散时间点如何改变淋巴和静脉膝关节间隙。运动通过保留糖胺聚糖含量和减少骨赘体积减轻与 PTOA 相关的关节退化（效应大小 (95% CI)；1.74 (0.71–2.26)。PTOA 增加后步宽度 (0.57 (0.18–0.95) cm），但运动纠正了这一点步态功能障碍（0.54（0.16-0.93）厘米），可能表明静脉疼痛缓解，但与基线相比，术后 1、3 和 6 周的疼痛清除更快。中度 PTOA 的清除率（3.39（0.20-6.59）小时）表明运动可能在恢复关节稳态方面发挥关键作用，我们得出结论，轻度运动有可能通过加速中度 PTOA 的关节清除来减缓疾病进展。