Heineman Nathan, Do Dang-Huy, Ahn Junho, Sammer Douglas M, Koehler Daniel M
Department of Orthopaedic Surgery, University of Texas Southwestern Medical Center, Dallas, Texas.
Department of Orthopaedic Surgery, University of Texas Southwestern Medical Center, Dallas, Texas; Department of Plastic Surgery, University of Texas Southwestern Medical Center, Dallas, Texas.
J Hand Surg Am. 2025 May;50(5):625.e1-625.e8. doi: 10.1016/j.jhsa.2024.01.007. Epub 2024 Feb 26.
Proximal interphalangeal (PIP) joint arthrodesis is a procedure employed to address arthritis, instability, and deformity. Multiple fixation methods are available to maintain stability across the arthrodesis interval, including headless compression screws (HCSs), tension band wiring (TBW), plating, and Kirschner wire constructs. The purpose of this study was to compare the biomechanical properties of the HCS and TBW techniques.
Thirty-two nonthumb digits from the paired upper limbs of four fresh frozen cadavers were divided into pairs, matching contralateral digits from the same specimen. One PIP joint of each pair was fused with an antegrade 3.5 mm HCS, and the second was fused with TBW using 0.035 in. Kirschner wires with 24-gauge dental wire. Each construct was then stressed to 10 N in the radial deviation, ulnar deviation, flexion, and extension planes, and stiffness (N/mm) was calculated. The fingers were stressed to failure in extension with the ultimate load and mode of failure recorded.
When stressed in extension, the HCS construct had a significantly greater mean stiffness than the TBW construct (16.4 N/mm vs 10.8 N/mm). The stiffness in all other planes of motion were similar between the two constructs. The mean ultimate load to failure in extension was 91.4 N for the HCS and 41.9 N for the TBW. The most common mode of failure was fracture of the dorsal lip of the proximal phalanx (13/16) for the HCS and bending of the K-wires (15/16) for TBW.
Arthrodesis of the PIP joint using a HCS resulted in a construct that was significantly stiffer in extension with greater than double the load to failure compared to TBW.
Although the stiffness required to achieve successful PIP joint arthrodesis has not been well quantified, the HCS proved to be the most favorable construct with respect to initial strength and stability.
近端指间（PIP）关节融合术是一种用于治疗关节炎、不稳定和畸形的手术。有多种固定方法可用于维持关节融合间隙的稳定性，包括无头加压螺钉（HCS）、张力带钢丝固定（TBW）、钢板固定和克氏针结构。本研究的目的是比较HCS和TBW技术的生物力学特性。
从4具新鲜冷冻尸体的双侧上肢获取32个非拇指手指，将其配对，使每对来自同一标本的对侧手指。每对中的一个PIP关节采用顺行3.5mm HCS进行融合，另一个采用0.035英寸克氏针加24号牙科钢丝进行TBW融合。然后对每个结构在桡偏、尺偏、屈曲和伸展平面施加10N的应力，并计算刚度（N/mm）。手指在伸展位承受直至破坏的应力，记录极限载荷和破坏模式。
在伸展位施加应力时，HCS结构的平均刚度显著高于TBW结构（16.4N/mm对10.8N/mm）。两种结构在所有其他运动平面的刚度相似。HCS在伸展位的平均极限破坏载荷为91.4N，TBW为41.9N。最常见的破坏模式是HCS组近端指骨背侧唇骨折（13/16），TBW组克氏针弯曲（15/16）。
使用HCS进行PIP关节融合术所形成的结构在伸展时刚度显著更高，与TBW相比，破坏载荷增加了一倍多。
尽管成功进行PIP关节融合术所需的刚度尚未得到很好的量化，但就初始强度和稳定性而言，HCS被证明是最有利的结构。
