Department of Orthopedic Surgery, School of Medicine, Keio University, Tokyo, Japan.
Department of Orthopedic Surgery, School of Medicine, Keio University, Tokyo, Japan; Department of Advanced Therapy for Musculoskeletal Disorders II, School of Medicine, Keio University, Tokyo, Japan; Department of Musculoskeletal Reconstruction and Regeneration Surgery, School of Medicine, Keio University, Tokyo, Japan.
Am J Sports Med. 2021 Nov;49(13):3508-3518. doi: 10.1177/03635465211041582. Epub 2021 Oct 13.
Although various reconstruction techniques are available for anterior cruciate ligament (ACL) injuries, a long recovery time is required before patients return to sports activities, as the reconstructed ACL requires time to regain strength. To date, several studies have reported use of mesenchymal stem cells in orthopaedic surgery; however, no studies have used adipose-derived stem cell (ADSC) sheets in ACL reconstruction (ACLR).
ADSC sheet transplantation can improve biomechanical strength of the autograft used in ACLR.
Controlled laboratory study.
A total of 68 healthy Japanese white rabbits underwent unilateral ACLR with a semitendinosus tendon autograft after random enrollment into a control group (no sheet; n = 34) and a sheet group (ADSC sheet; n = 34). At 2, 4, 8, 16, and 24 weeks after surgery, rabbits in each group were sacrificed to evaluate tendon-bone healing using histological staining, micro-computed tomography, and biomechanical testing. At 24 weeks, scanning transmission electron microscopy of the graft midsubstance was performed.
The ultimate failure load for the control and sheet groups, respectively, was as follows: 17.2 ± 5.5 versus 37.3 ± 10.3 ( = .01) at 2 weeks, 28.6 ± 1.9 versus 47.4 ± 10.4 ( = .003) at 4 weeks, 53.0 ± 14.3 versus 48.1 ± 9.3 ( = .59) at 8 weeks, 66.2 ± 9.3 versus 95.2 ± 43.1 ( = .24) at 16 weeks, and 66.7 ± 27.3 versus 85.3 ± 29.5 ( = .39) at 24 weeks. The histological score was also significantly higher in the sheet group compared with the control group at early stages up to 8 weeks. On micro-computed tomography, relative to the control group, the bone tunnel area was significantly narrower in the sheet group at 4 weeks, and the bone volume/tissue volume of the tendon-bone interface was significantly greater at 24 weeks. Scanning transmission electron microscopy at 24 weeks indicated that the mean collagen fiber diameter in the midsubstance was significantly greater, as was the occupation ratio of collagen fibers per field of view, in the sheet group.
ADSC sheets improved biomechanical strength, prevented bone tunnel enlargement, and promoted tendon-bone interface healing and graft midsubstance healing in an in vivo rabbit model.
ADSC sheets may be useful for early tendon-bone healing and graft maturation in ACLR.
尽管有多种重建技术可用于前交叉韧带（ACL）损伤，但患者在恢复运动活动之前需要较长的恢复期，因为重建的 ACL 需要时间来恢复强度。迄今为止，已有多项研究报道了间充质干细胞在骨科手术中的应用；然而，尚无研究将脂肪来源的干细胞（ADSC）片应用于 ACL 重建（ACLR）中。
ADSC 片移植可以提高 ACLR 中使用的自体移植物的生物力学强度。
对照实验室研究。
总共 68 只健康的日本白兔在单侧 ACLR 后随机入组接受半腱肌腱自体移植物，分别进入对照组（无片；n = 34）和片组（ADSC 片；n = 34）。手术后 2、4、8、16 和 24 周，每组处死兔子，通过组织学染色、微计算机断层扫描和生物力学测试评估肌腱-骨愈合情况。在 24 周时，对移植物中间物质进行扫描传输电子显微镜检查。
对照组和片组的最终失效负荷分别为：2 周时为 17.2 ± 5.5 与 37.3 ± 10.3（ =.01），4 周时为 28.6 ± 1.9 与 47.4 ± 10.4（ =.003），8 周时为 53.0 ± 14.3 与 48.1 ± 9.3（ =.59），16 周时为 66.2 ± 9.3 与 95.2 ± 43.1（ =.24），24 周时为 66.7 ± 27.3 与 85.3 ± 29.5（ =.39）。在早期（8 周内），组织学评分也明显高于对照组。在微计算机断层扫描中，与对照组相比，片组在 4 周时骨隧道区域明显变窄，24 周时肌腱-骨界面的骨体积/组织体积明显增加。24 周时的扫描传输电子显微镜检查表明，片组的中体平均胶原纤维直径明显增大，视野内胶原纤维的占有率也明显增大。
ADSC 片在体内兔模型中改善了生物力学强度，防止了骨隧道扩大，并促进了肌腱-骨界面愈合和移植物中间物质愈合。
ADSC 片可能有助于 ACLR 中早期的肌腱-骨愈合和移植物成熟。
