Preston Nathaniel, Peterson Daniel, Allen Jamey, Kawalec Jill S, Whitaker Jeffrey
Grant Medical Center, Columbus, Ohio (NP).
Detroit Medical Center, Detroit, Michigan (DP).
Foot Ankle Spec. 2018 Aug;11(4):342-346. doi: 10.1177/1938640017735888. Epub 2017 Oct 19.
In the dorsal incisional approach for Morton's neuroma, it is required to transect the deep transverse metatarsal ligament (DTML) that lies in the interspace between the third and fourth metatarsal heads. The purpose of this study was to evaluate the relationship between transection of the DTML in the third intermetatarsal space and the metatarsal alignment.
Nine human cadaveric lower extremity limbs were used for this study. Each limb was mounted to the MTS 858 Mini Bionix biomechanical test system and loaded to 120% of the donor's documented body weight at a rate of 15 lbf/s, in order to simulate peak weightbearing ground reactive forces on the forefoot. Preoperative and immediate postoperative radiographs were obtained. Cyclic loading was then performed to simulate 1 month of full weightbearing. Radiographs were repeated and metatarsal alignment was analyzed.
A statistically significant difference was noted with intermetatarsal angle (IMA) 1-2 and IMA 1-4. The IMA 1-2 after 1 month cycling time showed statistical significant difference from those found immediately postoperatively (P < .05). Average increase in IMA 1-2 from preoperative to 1 month cycling time was 2.18°. The power of the analyses for IMA 1-2 was 0.992. Regarding the IMA 1-4, data recorded at 1 week and 1 month cycling times showed a statistically significant difference compared to the preoperative IMA 1-4 (P < .05). Average increase in IM 1-4 angles from preoperative to 1 month cycling time was an increase of 1.79°. The power of the analyses for IM 1-4 angles was 0.953.
Technically, 2.18° increase in IMA 1-2 or 1.79° increase in IM 1-4 would be considered an abnormal widening of the forefoot, but clinically, these values could not be detected; nor should they deter a surgeon or patient from undergoing a Morton's neurectomy via a dorsal incisional approach.
Level V: Cadaveric study.
在用于治疗莫顿神经瘤的背侧切口入路中，需要横断位于第三和第四跖骨头间隙的跖骨深横韧带（DTML）。本研究的目的是评估在第三跖骨间隙横断DTML与跖骨排列之间的关系。
本研究使用了9具人类尸体下肢。将每个下肢安装到MTS 858 Mini Bionix生物力学测试系统上，并以15磅力/秒的速率加载至供体记录体重的120%，以模拟前足的峰值负重地面反作用力。获得术前和术后即刻的X线片。然后进行循环加载以模拟1个月的完全负重。重复拍摄X线片并分析跖骨排列。
第一和第二跖骨间角（IMA 1-2）以及第一和第四跖骨间角（IMA 1-4）存在统计学显著差异。循环加载1个月后的IMA 1-2与术后即刻的IMA 1-2相比有统计学显著差异（P <.05）。从术前到循环加载1个月时，IMA 1-2的平均增加量为2.18°。IMA 1-2分析的效能为0.992。关于IMA 1-4，在循环加载1周和1个月时记录的数据与术前IMA 1-4相比有统计学显著差异（P <.05）。从术前到循环加载1个月时，IM 1-4角的平均增加量为1.79°。IM 1-4角分析的效能为0.953。
从技术上讲，IMA 1-2增加2.18°或IM 1-4增加1.79°可被视为前足的异常增宽，但在临床上，这些值无法检测到；它们也不应阻止外科医生或患者通过背侧切口入路进行莫顿神经切除术。
V级：尸体研究。
