San Francisco Shoulder, Elbow, and Hand Clinic, 2351 Clay Street, Suite 510, San Francisco, CA, 94115, USA.
Clin Orthop Relat Res. 2014 Jun;472(6):1930-5. doi: 10.1007/s11999-014-3478-0. Epub 2014 Feb 11.
Reliable methods of fixation of soft tissue and bone are of utmost importance in reconstructive shoulder surgery and in many orthopaedic applications. Current methods of securing lesser tuberosity osteotomies performed during shoulder arthroplasty and tuberosity fixation performed during repair of proximal humeral fractures often rely on alternating half hitches or surgeon's knots regardless of the suture configuration used passing through the tissue (eg, Mason-Allen, Krackow). The racking hitch knot in contrast to half hitches allows sequential tightening, even under tension, with minimal risk of knot slippage or premature locking. These knot characteristics allow the surgeon to stepwise improve their reduction before committing and locking a construct, preventing hanging knots or under-tensioned repairs. However, little data exist to support the use the racking hitch knot to guide decision making regarding how to back up the knot or to explain the effect of suture material on security and strength.
QUESTIONS/PURPOSES: The objectives of our study were (1) to identify the optimal number of half hitches necessary to maintain knot security for a single knot; (2) to evaluate if a difference exists in the relative behavior of racking hitch knots when tied using different suture materials; and (3) to define the biomechanical differences between the racking hitch and two other knot configurations commonly used in shoulder surgery (Weston and square knots).
Using an Instron device we tested the effect of adding supplemental half hitches (from one to four) to the racking hitch. Additionally, a selection of commercially available braided nonabsorbable polyethylene sutures and different knot configurations (racking hitch, Weston knot, and square knot) also were tested. Data were compared using ANOVA.
Increasing the number of half hitches improved knot performance in peak load testing and cyclic testing, revealing a significant difference between the racking hitch supplemented with one and four half hitches (199.2 N versus 428.8 N, p < 0.05). Force Fiber™ #2 (359.6 N) and FiberWire(®) #2 (302 N) showed increased loads to failure compared with Ethibond Excel™ #2 or Force Fiber™ #3/4, whereas Ethibond Excel™ had the least amount of slippage during cyclic testing (0.09 mm). The racking hitch knot had considerably higher loads to failure (359.6 N) than the Weston (145.2 N) or square (77 N) knots.
The racking hitch knot exhibited significantly higher loads to failure and comparable knot slippage (elongation during cyclic testing) when compared with other commonly used knots. According to the biomechanical data, the addition of four half hitches to supplement the racking hitch and the choice of FiberWire(®) #2 or Force Fiber™ #2 suture resulted in increased knot security.
This knot adds a tool to the arsenal for surgeons best suited for repairs requiring a high degree of knot security and reliable tissue tensioning.
在重建肩部手术和许多骨科应用中，固定软组织和骨骼的可靠方法至关重要。目前，在肩关节置换术中固定小结节截骨术和修复肱骨近端骨折时固定小结节的方法通常依赖于交替的半结或外科结，无论穿过组织的缝线配置如何（例如 Mason-Allen、Krackow）。与半结相比， Rack 结允许在有张力的情况下顺序收紧，结滑或过早锁定的风险最小。这些结的特性允许外科医生在进行构建之前逐步改善他们的复位，防止悬挂结或张力不足的修复。然而，几乎没有数据支持使用 Rack 结来指导决策，以确定如何备份结或解释缝线材料对安全性和强度的影响。
问题/目的：我们研究的目的是：(1)确定单个结保持结安全性所需的半结数量；(2)评估使用不同缝线材料时 Rack 结的相对行为是否存在差异；(3)定义 Rack 结与肩部手术中常用的两种其他结构型(Weston 和方结)之间的生物力学差异。
我们使用 InStron 设备测试了向 Rack 结添加补充半结(从一个到四个)的效果。此外，还测试了各种市售的编织非吸收性聚乙二醇缝线和不同的结构型( Rack 结、Weston 结和方结)。使用方差分析比较数据。
增加半结的数量可提高峰值负载测试和循环测试中的结性能，表明补充一个和四个半结的 Rack 结之间存在显著差异(199.2 N 与 428.8 N，p < 0.05)。Force Fiber™#2(359.6 N)和 FiberWire(®)#2(302 N)与 Ethibond Excel™#2 或 Force Fiber™#3/4 相比，显示出更高的失效负载，而 Ethibond Excel™ 在循环测试中的滑移最小(0.09 mm)。 Rack 结的失效负载(359.6 N)明显高于 Weston(145.2 N)或 Square(77 N)结。
与其他常用结相比， Rack 结表现出显著更高的失效负载和相当的结滑移(循环测试中的伸长)。根据生物力学数据，向 Rack 结添加四个半结并选择 FiberWire(®)#2 或 Force Fiber™#2 缝线可提高结的安全性。
对于需要高度结安全性和可靠组织张力的修复手术，这种结为外科医生提供了一种更有效的工具。
