Stanford, Calif. From the Division of Plastic Surgery, Veterans Affairs Palo Alto Health Care System, and the Division of Plastic Surgery, Stanford University Medical Center.
Plast Reconstr Surg. 2014 Jan;133(1):79-89. doi: 10.1097/01.prs.0000436823.64827.a0.
Restoration of biomechanical strength following surgical reconstruction of tendon or ligament insertion tears is challenging because these injuries typically heal as fibrous scars. The authors hypothesize that injuries at the tendon-bone interface would benefit from reconstruction with decellularized composite tendon-bone grafts.
Tendon-bone grafts were harvested from Sprague-Dawley rats. Grafts subjected to decellularization were compared histologically and biomechanically with untreated grafts ex vivo and in a new in vivo model. Wistar rats underwent Sprague-Dawley allograft reconstruction using a pair-matched design. The rats were killed at 2 or 4 weeks. B-cell and macrophage infiltration was determined using immunohistochemistry, and explants were tested biomechanically.
Decellularization resulted in a decrease in cells from 164 ± 61 (untreated graft) to 13 ± 7 cells per high-power field cells (p < 0.005) and a corresponding significant decrease in DNA content, and preserved scaffold architecture of the tendon-bone interface. Biomechanical comparison revealed no difference in failure load (p = 0.32), ultimate tensile stress (p = 0.76), or stiffness (p = 0.22) between decellularized grafts and untreated controls. Following in vivo reconstruction with tendon-bone interface grafts, decellularized grafts were stronger than untreated grafts at 2 weeks (p = 0.047) and at 4 weeks (p < 0.005). A persistent increase in B-cell and macrophage infiltration was observed in both the capsule surrounding the tendon-bone interface and the tendon substance in untreated controls.
Decellularized tendon-bone grafts display better biomechanical properties at early healing time points and a decreased immune response compared with untreated grafts in vivo.
肌腱或韧带附着处撕裂后，恢复生物力学强度具有挑战性，因为这些损伤通常以纤维瘢痕的形式愈合。作者假设肌腱-骨界面的损伤将受益于去细胞复合肌腱-骨移植物的重建。
从 Sprague-Dawley 大鼠中获取肌腱-骨移植物。体外和新的体内模型中，对去细胞化的移植物与未经处理的移植物进行组织学和生物力学比较。Wistar 大鼠采用 Sprague-Dawley 同种异体移植物重建，采用配对设计。大鼠在 2 或 4 周时处死。通过免疫组织化学测定 B 细胞和巨噬细胞浸润，对标本进行生物力学测试。
去细胞化导致细胞数量从 164 ± 61（未经处理的移植物）减少到 13 ± 7 个/高倍视野（p < 0.005），DNA 含量相应显著减少，并保留了肌腱-骨界面的支架结构。生物力学比较显示，去细胞化移植物与未经处理的对照组在失效负荷（p = 0.32）、极限拉伸应力（p = 0.76）或刚度（p = 0.22）方面没有差异。在肌腱-骨界面移植物的体内重建后，去细胞化移植物在 2 周（p = 0.047）和 4 周（p < 0.005）时比未经处理的移植物更强。未处理对照组的肌腱-骨界面周围囊和肌腱实质中均观察到 B 细胞和巨噬细胞浸润持续增加。
与未经处理的移植物相比，去细胞化肌腱-骨移植物在早期愈合时间点具有更好的生物力学性能和降低的免疫反应。
