不同肌腱缝合方法的生物力学比较研究

Biomechanical study of different suture methods in repairing tendon rupture

目的评价改良Kessler缝合联合"8"字缝合修复肌腱的生物力学性能,为其用于临床修复急性跟腱断裂提供依据。方法取40条猪后肢趾长屈肌腱,随机分为4组(n=10),A组:制备急性横行切割伤,采用Krackow缝合方法缝合;B、C、D组:制备急性马尾样损伤后,分别采用Krackow缝合、Kessler缝合、改良Kessler缝合联合"8"字缝合方法缝合。将各组缝合后的肌腱固定于万能材料试验机,测量上、下端夹子之间肌腱实际长度,肌腱两端及中点3个截面的长轴和短轴长度,计算肌腱横截面积;然后以15 mm/min速度行拉伸测试,直至缝合失效(缝线脱出或者缝线断裂等),绘制负载-位移曲线,计算最大载荷、最大应力、最大应变、失效位移及刚度。结果各组肌腱实际长度及横截面积比较,差异无统计学意义(F=0.245,P=0.863;F=0.094,P=0.963)。加载负荷后,B组2例、C组1例、D组1例标本发生滑脱,未纳入统计学分析;A、B组肌腱均因缝线断裂而失效,C组由于缝线自肌腱组织内撕脱而失效,D组由于肌腱上3条缝线一起自缝合部位撕脱而失效。A、B组肌腱最大载荷、最大应力、最大应变、失效位移以及刚度比较,差异均无统计学意义(P>0.05)。D组最大载荷、最大应力以及刚度均明显大于B、C组,差异有统计学意义(P<0.05);最大应变、失效位移与B、C组比较,差异无统计学意义(P>0.05)。B组最大载荷、最大应力、失效位移以及刚度均大于C组,差异有统计学意义(P<0.05),两组最大应变差异无统计学意义(P>0.05)。结论改良Kessler缝合联合"8"字缝合方法可提供优于Krackow缝合和Kessler缝合的生物力学性能。

Objective To evaluate the biomechanical property of tendons repaired with the modified Kessler suture combined with ＂ 8” suture, and to provide evidence for the clinical application of this suture methods in repairing acute Achilles tendon rupture. Methods Forty frozen flexor digitorum longus tendons from fresh pork hind leg were randomly assigned into 4 groups, 10 specimens each group. In group A, the tendons were dissected transversely at the midpoint to forming the model of tendon with transversely cutting injury. The tendons in groups B, C, and D were dissected transversely at the midpoint, then a 2 cm segment of tendon from the incision in each side was dissected longitudinally with 1 mm internal to forming ＂ frayed tendon” model. All the tendons were sutured with2-0 non-absorbable suture material with different suturing methods： in group A, the tendons with transversely cutting injury model with Krackow suture, and in the groups B, C, and D with Krackow suture, Kessler suture, and the modified Kessler suture combined with ＂ 8” suture separately. All repaired tendons were fixed onto the biomechanical testing machine. The length, width, and thickness of each side and midpoint of the tendons were recorded, and the cross-sectional area was calculated. The tendons were stretched at a speed of 15 mm/minutes until failure （suture avulsion or rupture）. The computer automatically recorded the maximum load, stress, strain, the failure displacement, and the stiffness. These biomechanical parameters of tendons in different groups were analyzed and compared. Results There was no significant difference in the length and cross-sectional area of each tendon among 4 groups （F=0.245, P=0.863; F=0.094, P=0.963）. Two tendons in group B, 1 in group C, and 1 in group D were excluded because of tendon slipping; all tendons in group A and 8 tendons in group B failured due to suture rupture, 9 tendons in group C due to suture slipping, and 9 tendons in group D due to 3 sutures slipping from tendon tissue together. The maximum load, the maximum stress, the maximum strain, the failure displacement, and the stiffness of the tendons between groups A and B showed no significant difference （P〉0.05）. The maximum load, the maximum stress, and the stiffness of the tendons in group D were larger than those in both groups B and C （P〈0.05）, but no significant difference was found in the maximum strain and the failure displacement between groups B, C, and D （P〉0.05）. The maximum load, the maximum stress, the failure displacement, and the stiffness of the tendons in group B were larger than those in group C （P〈0.05）, but the difference of maximum strain between groups B and C was not significant （P〉0.05）. Conclusion The modified Kessler suture combined with ＂ 8” suture can provide better biomechanical property of the repaired tendon compared with other suture approaches.