Department of Orthopedic Surgery, University of Basel, Basel, Switzerland.
Rehabilitation Medicine Research Center, Mayo Clinic, Rochester, Minnesota, USA.
Am J Sports Med. 2018 Apr;46(5):1214-1219. doi: 10.1177/0363546518756093. Epub 2018 Mar 5.
The role of the paratenon in tendon healing is unknown. The present study compares healing in the presence or absence of the paratenon in an Achilles tendon defect model in rats.
Resection of the paratenon impairs tendon healing.
Controlled laboratory study.
Sixty skeletally mature Sprague Dawley rats were randomly assigned to either a resected paratenon (RP) group or an intact paratenon (IP) group. In all animals, a 4-mm portion of the Achilles tendon was resected in the midsubstance. In the RP group, the paratenon was resected completely. In the IP group, the paratenon was opened longitudinally and closed again after the tendon defect had been created. One, 2, and 4 weeks after surgery, 7 animals per group were tested biomechanically and 3 animals per group examined histologically.
The recovery of mechanical strength was much more rapid in IP tendons. Tear resistance was significantly increased for IP tendons (41.3 ± 8.8 N and 47.3 ± 14.1 N, respectively) compared with RP tendons (19.3 ± 9.1 N and 33.2 ± 6.4 N, respectively) after 1 and 2 weeks. The cross-sectional area was larger in the IP group after 1 and 2 weeks (8.2 ± 2.3 mm and 11.3 ± 3.1 mm vs 5.0 ± 2.4 mm and 5.9 ± 2.0 mm, respectively) compared with the RP group. Tendon stiffness was greater in the IP group after 1 week (10.4 ± 1.9 N/mm vs 4.5 ± 1.6 N/mm, respectively) compared with the RP group. In comparison, normal contralateral tendons had a maximal tear resistance of 56.6 ± 7.2 N, a cross-sectional area of 3.6 ± 0.7 mm, and stiffness of 17.3 ± 3.8 N/mm. Hematoxylin and eosin staining revealed slightly delayed healing of RP tendons. Early collagen formation was seen in the IP group already after 1 week, whereas in the RP group, this only occurred after 2 weeks. After 4 weeks, the IP tendons showed more collagen crimp formation than the RP tendons.
An intact paratenon promotes healing of the Achilles tendon.
Although incision or resection of the paratenon has been advocated when repairing injured or degenerative tendons, our data suggest that the integrity of the paratenon should be preserved.
腱旁组织在肌腱愈合中的作用尚不清楚。本研究比较了在大鼠跟腱缺损模型中存在或不存在腱旁组织时的愈合情况。
切除腱旁组织会损害肌腱愈合。
对照实验室研究。
60 只骨骼成熟的 Sprague Dawley 大鼠被随机分配到切除腱旁组织（RP）组或完整腱旁组织（IP）组。在所有动物中，在跟腱的中体部分切除 4mm 部分。在 RP 组中，完全切除腱旁组织。在 IP 组中，腱旁组织被纵向切开，在创建腱缺损后再次闭合。术后 1、2 和 4 周，每组 7 只动物进行生物力学测试，每组 3 只动物进行组织学检查。
IP 肌腱的机械强度恢复更快。与 RP 肌腱（分别为 19.3 ± 9.1 N 和 33.2 ± 6.4 N）相比，IP 肌腱（分别为 41.3 ± 8.8 N 和 47.3 ± 14.1 N）的抗撕裂强度在 1 周和 2 周时显著增加。与 RP 组相比，1 周和 2 周时 IP 组的横截面积更大（分别为 8.2 ± 2.3 mm 和 11.3 ± 3.1 mm 与 5.0 ± 2.4 mm 和 5.9 ± 2.0 mm）。与 RP 组相比，1 周时 IP 组的肌腱刚度更大（分别为 10.4 ± 1.9 N/mm 和 4.5 ± 1.6 N/mm）。相比之下，正常对侧肌腱的最大抗撕裂强度为 56.6 ± 7.2 N，横截面积为 3.6 ± 0.7 mm，刚度为 17.3 ± 3.8 N/mm。苏木精-伊红染色显示 RP 肌腱的愈合稍延迟。在 IP 组中，仅在 1 周后就已观察到早期胶原形成，而在 RP 组中，仅在 2 周后才发生这种情况。4 周后，与 RP 肌腱相比，IP 肌腱的胶原卷曲形成更多。
完整的腱旁组织促进跟腱愈合。
尽管在修复受伤或退行性肌腱时已提倡切开或切除腱旁组织，但我们的数据表明应保留腱旁组织的完整性。
