Kannan Sudhir, Ghosh Arijit I, Dias Joseph J, Singh Harvinder Pal
1 Department of Orthopaedic Surgery, Leicester General Hospital, Leicester, UK.
J Hand Surg Asian Pac Vol. 2019 Mar;24(1):76-82. doi: 10.1142/S2424835519500140.
Strong surgical repair is the mechanical basis of early mobilization and prerequisite for biological healing following tendon grafting. Side to side and pulvertaft repairs were developed to meets these demands. However, these techniques have later been modified to improve the strength of repair but their characteristics have not been compared.
We compared biomechanical strength of the modified side-to-side (SS) repair with the modified Pulvertaft (PT) repair technique in turkey tendons keeping overlap length, anchor points, type of suture, suture throw and amount of suture similar. Two investigators performed 34 repairs during one summer month to test the tensile strength of the repair using mechanical strength testing machine. Variables measured were maximum load, load to first failure, modulus, load at break, mode of failure, site of failure, tensile strain, tensile stress. The statistical comparison was carried by Levene's test and T test for means.
The mean maximum load for modified SS repair was 50.3 (SD 13.7) N and modified PT repair was 46.9 (SD 16.4) N. The tensile stress at maximum load for SS and modified PT repair was 4.7 (SD 4) MPa and 4.2 (SD 3) MPa respectively. The suture cut through was the commonest mode of failure.
We found no statistical difference between 2 repairs in load at which they started failing (p = 0.16), and maximum load repairs could withstand (p = 0.35). Our study uniquely compares two techniques under standard conditions, and contrary to existing evidence found no difference. However, in our opinion the number of anchor points may have a greater impact than number of weaves on the strength.
强大的手术修复是早期活动的力学基础，也是肌腱移植后生物愈合的前提条件。端对端和Pulvertaft修复技术应运而生以满足这些需求。然而，这些技术后来经过改良以提高修复强度，但它们的特点尚未得到比较。
我们在火鸡肌腱中比较了改良端对端（SS）修复与改良Pulvertaft（PT）修复技术的生物力学强度，保持重叠长度、锚点、缝线类型、缝线穿过次数和缝线数量相似。两位研究者在一个夏季月份内进行了34次修复，使用机械强度测试机测试修复的拉伸强度。测量的变量包括最大负荷、首次失效负荷、模量、断裂负荷、失效模式、失效部位、拉伸应变、拉伸应力。通过Levene检验和均值T检验进行统计学比较。
改良SS修复的平均最大负荷为50.3（标准差13.7）N，改良PT修复为46.9（标准差16.4）N。SS和改良PT修复在最大负荷时的拉伸应力分别为4.7（标准差4）MPa和4.2（标准差3）MPa。缝线切断是最常见的失效模式。
我们发现两种修复在开始失效时的负荷（p = 0.16）以及修复能够承受的最大负荷（p = 0.35）方面没有统计学差异。我们的研究在标准条件下独特地比较了两种技术，与现有证据相反，未发现差异。然而，我们认为锚点数量可能比编织次数对强度的影响更大。
