Department of Orthopedic Surgery, Kurume University School of Medicine, Kurume, Japan.
Department of Orthopedic Surgery, Kurume University Medical Center, Kurume, Japan.
Am J Sports Med. 2017 Dec;45(14):3322-3330. doi: 10.1177/0363546517720199. Epub 2017 Sep 5.
There is growing evidence that the subacromial injection of hyaluronic acid (HA) is effective for pain relief in rotator cuff tears; however, its effect on tendon-to-bone healing remains unknown.
To examine the effect of HA on the chondrogenesis of mesenchymal stem cells (MSCs) in vitro and on tendon-to-bone healing in a rotator cuff repair model.
Controlled laboratory study.
Bilateral complete tears of the infraspinatus tendon were made in rabbits and subsequently repaired. Before closure, 1 mL HA was applied to the repaired site, and phosphate-buffered saline was used in the opposite side as a control. Biomechanical, histological, and immunohistochemical analyses were performed at 4, 8, and 12 weeks after surgery. After euthanizing each animal, the bone marrow was isolated from the femoral bone in the same rabbits. Then, MSCs were cultured in media for chondrogenic differentiation, and the chondral pellet production and cartilage-related gene expression levels in the cells were examined at various concentrations of HA.
At 4 and 8 weeks after surgery, ultimate load-to-failure was significantly greater in the HA group than in the control group (45.61 ± 9.0 N vs 32.42 ± 9.4 N at 4 weeks, 90.7 ± 16.0 N vs 66.97 ± 10.0 N at 8 weeks; both P < .05) but not at 12 weeks after surgery (109.6 ± 40.2 N vs 108.1 ± 42.6 N, P > .05). Linear stiffness was not significant throughout the time point evaluation. The chondroid formation area at the tendon-bone interface stained by safranin O (control vs HA group) was 0.33% ± 0.7% versus 13.5% ± 12.3% at 4 weeks after surgery ( P < .05) and 3.0% ± 5.9% versus 12.9% ± 12.9% at 8 weeks after surgery ( P < .05), but there was no significant difference at 12 weeks after surgery. Maturity of collagen at the repaired site stained by PicroSirius Red (control vs HA group) was 16.2 ± 10.6 versus 43.5 ± 21.3 at 4 weeks after surgery ( P < .05), but there were no significant differences at 8 and 12 weeks after surgery. MSCs were cultured in media for chondrogenic differentiation, and the chondral pellet production and cartilage-related gene expression levels in the cells were examined at various concentrations of HA. The number of CD44-positive cells (control vs HA group) was 8.3% ± 1.4% versus 26.2% ± 5.2% at 3 days after surgery ( P < .05), 1.8% ± 1.1% versus 26.6% ± 11.6% at 4 weeks after surgery ( P < .05), 0.6% ± 0.9% versus 0.5% ± 0.6% at 8 weeks after surgery ( P > .05), and 1.8% ± 4.0% versus 5.4% ± 4.2% at 12 weeks after surgery ( P > .05). Compared with the control group, HA significantly increased the volume of cartilaginous pellet produced by MSCs (0.0016 ± 0.0015 mm at 0 mg/mL of HA, 0.0041 ± 0.0023 mm at 1.0 mg/mL, and 0.0041 ± 0.0018 mm at 4.0 mg/mL), with increased mRNA expression (relative ratio to control) of type 2 collagen (1.34 ± 0.38), SOX9 (1.58 ± 0.31), and aggrecan (1.30 ± 0.22) genes in the pellet ( P < .01).
HA accelerated tendon-to-bone healing in the rotator cuff repair model, enhancing the biomechanical strength and increasing chondroid formation and tendon maturity at the tendon-bone interface. Based on the data of in vitro experiments, HA-activated MSCs may play a crucial role in the acceleration of tendon-to-bone healing.
The data suggest the relevance of clinical application of HA to accelerate tendon-to-bone healing. It may decrease the number of retears after surgery.
越来越多的证据表明，肩峰下注射透明质酸（HA）对肩袖撕裂引起的疼痛缓解有效；然而，其对腱骨愈合的影响尚不清楚。
研究 HA 对骨髓间充质干细胞（MSCs）体外软骨形成的影响以及对肩袖修复模型中腱骨愈合的影响。
对照实验室研究。
在兔子双侧冈下肌完全撕裂后进行修复。在关闭前，将 1 mL HA 应用于修复部位，另一侧用磷酸盐缓冲盐水作为对照。术后 4、8 和 12 周进行生物力学、组织学和免疫组织化学分析。在每个动物安乐死后，从同一只兔子的股骨中分离骨髓。然后，将 MSCs 在用于软骨分化的培养基中培养，并在不同浓度的 HA 下检查细胞中软骨小球的产生和软骨相关基因的表达水平。
术后 4 周和 8 周时，HA 组的最终失效负荷明显大于对照组（45.61 ± 9.0 N 对 4 周时的 32.42 ± 9.4 N，90.7 ± 16.0 N 对 8 周时的 66.97 ± 10.0 N；均 P <.05），但术后 12 周时无差异（109.6 ± 40.2 N 对 108.1 ± 42.6 N，P >.05）。整个时间点评估时线性刚度均无显著差异。术后 4 周时，HA 组与对照组的软骨样形成面积在腱骨界面染色的番红 O（SAFRIN O）（HA 组与对照组）分别为 0.33% ± 0.7%与 13.5% ± 12.3%（P <.05），8 周时分别为 3.0% ± 5.9%与 12.9% ± 12.9%（P <.05），但术后 12 周时无显著差异。术后 4 周时，用 PicroSirius Red 染色的修复部位胶原成熟度（HA 组与对照组）分别为 16.2 ± 10.6 与 43.5 ± 21.3（P <.05），但术后 8 周和 12 周时无显著差异。将 MSCs 在用于软骨分化的培养基中培养，并在不同浓度的 HA 下检查细胞中软骨小球的产生和软骨相关基因的表达水平。术后 3 天时 CD44 阳性细胞的数量（HA 组与对照组）分别为 8.3% ± 1.4%与 26.2% ± 5.2%（P <.05），4 周时分别为 1.8% ± 1.1%与 26.6% ± 11.6%（P <.05），8 周时分别为 0.6% ± 0.9%与 0.5% ± 0.6%（P >.05），12 周时分别为 1.8% ± 4.0%与 5.4% ± 4.2%（P >.05）。与对照组相比，HA 显著增加了 MSCs 产生的软骨小球体积（0 mg/mL 的 HA 为 0.0016 ± 0.0015 mm，1.0 mg/mL 为 0.0041 ± 0.0023 mm，4.0 mg/mL 为 0.0041 ± 0.0018 mm），并增加了小球中软骨相关基因（2 型胶原、SOX9 和聚集蛋白）的 mRNA 表达（与对照组相比的相对比值）（P <.01）。
HA 加速了肩袖修复模型中的腱骨愈合，增强了生物力学强度，并增加了腱骨界面的软骨样形成和腱成熟度。基于体外实验数据，HA 激活的 MSCs 可能在加速腱骨愈合中发挥关键作用。
这些数据提示了 HA 临床应用加速腱骨愈合的相关性。它可能会减少手术后再撕裂的数量。
