Lehtonen Eva, Patel Harshadkumar, Lee Sung, LaCorda John, McKissack Haley M, Naranje Sameer, Shah Ashish
University of Alabama at Birmingham, 1313 13th Street South, Birmingham, AL, 35205, USA.
Foot (Edinb). 2019 Dec;41:19-23. doi: 10.1016/j.foot.2019.05.006. Epub 2019 May 18.
First tarsometatarsal (TMT) joint fusion is routinely used for arthritis and deformities. Common fixation methods include a locking plate construct, cross-screws, or combinations of the two. Cross screws have proven effective for union and stability; however, there is a potential for harm to nearby neurovascular structures due to the nature of percutaneous insertion technique. This study assessed risk of damage to the superficial peroneal nerve with percutaneous TMT fusion.
Nine fresh-frozen cadaver specimens were included. A medial incision in the internervous plane was made for TMT joint preparation. Two crossed percutaneous wires followed by 4.0 cc screws were placed in the dorsal aspect of the proximal aspect of first metatarsal and in the medial cuneiform. Both were 10-15 mm from the TMT joint line. The dorsal aspect of the foot was dissected and examined for neurovascular interruptions, particularly branches of the superficial peroneal nerve.
Results showed a mean distance of 4.33 mm from the proximal pin to the medial branch of the superficial peroneal nerve. The distal pin had a mean distance of 6.44 mm from the medial branch, with one pin 9 mm from the lateral branch. One incident of direct injury to the neurovascular bundle was observed.
Preparing the joint from the medial side using a percutaneous approach is less invasive, but presents a relative risk for neuritis. Care should be taken during insertion of the percutaneous screw after TMT joint preparation for fusion.
Level V, cadaver study.
第一跖跗（TMT）关节融合术常用于治疗关节炎和畸形。常见的固定方法包括锁定钢板结构、交叉螺钉或两者结合。交叉螺钉已被证明对关节愈合和稳定性有效；然而，由于经皮插入技术的性质，存在损伤附近神经血管结构的可能性。本研究评估了经皮TMT融合术对腓浅神经造成损伤的风险。
纳入9个新鲜冷冻尸体标本。在神经间平面做内侧切口以准备TMT关节。在第一跖骨近端背侧和内侧楔骨中置入两根交叉的经皮导丝，随后置入4.0 cc螺钉。两者均距TMT关节线10 - 15毫米。解剖足部背侧并检查神经血管有无中断，特别是腓浅神经的分支。
结果显示，近端钢针到腓浅神经内侧支的平均距离为4.33毫米。远端钢针到内侧支的平均距离为6.44毫米，其中一根钢针距外侧支9毫米。观察到1例神经血管束直接损伤事件。
采用经皮入路从内侧准备关节创伤较小，但存在神经炎的相对风险。在TMT关节准备融合后经皮置入螺钉时应小心操作。
V级，尸体研究。
