Kokubo Tetsuro, Hashimoto Takeshi, Suda Yasunori, Waseda Akeo, Ikezawa Hiroko
1 Department of Orthopedics Surgery, Kyosai Tachikawa Hospital, Tachikawa City, Tokyo, Japan.
2 Sports Medicine Research Center, Keio University, Yokohama City, Kanagawa, Japan.
Foot Ankle Int. 2017 Dec;38(12):1374-1379. doi: 10.1177/1071100717728579. Epub 2017 Sep 21.
Second metatarsophalangeal (MTP) joint dislocation is associated with hallux valgus, and the treatment of complete dislocation can be difficult. The purpose of this study was to radiographically clarify the characteristic foot shape in the presence of second MTP joint dislocation.
Weight-bearing foot radiographs of the 268 patients (358 feet) with hallux valgus were examined. They were divided into 2 groups: those with second MTP joint dislocation (study group = 179 feet) and those without dislocation (control group = 179 feet). Parameters measured included the hallux valgus angle (HVA), first-second intermetatarsal angle (IMA), second MTP joint angle, hallux interphalangeal angle (IPA), second metatarsal protrusion distance (MPD), metatarsus adductus angle (MAA), and the second metatarsal declination angle (2MDA). Furthermore, the dislocation group was divided into 3 subgroups according to second toe deviation direction: group M (medial type), group N (neutral type), and group L (lateral type).
The IPA and the 2MDA were significantly greater in the study group than in the control group. By multiple comparison analysis, the IMA was greatest in group M and smallest in group L. The IPA was smaller and 2MDA greater in group N than in group L. The HVA and MAA in group L were greatest, and MPD in group L was smallest.
The patients with second MTP joint dislocation associated with hallux valgus had greater hallux interphalangeal joint varus and a second metatarsal more inclined than with hallux valgus alone. The second toe deviated in a different direction according to the foot shape.
Level III, retrospective comparative study.
第二跖趾关节脱位与拇外翻相关，完全脱位的治疗可能具有挑战性。本研究的目的是通过影像学明确第二跖趾关节脱位时足部的特征性形态。
对268例（358足）拇外翻患者的负重足部X线片进行检查。将患者分为2组：第二跖趾关节脱位组（研究组 = 179足）和无脱位组（对照组 = 179足）。测量的参数包括拇外翻角（HVA）、第一-第二跖骨间角（IMA）、第二跖趾关节角、拇趾间关节角（IPA）、第二跖骨突出距离（MPD）、跖骨内收角（MAA）和第二跖骨倾斜角（2MDA）。此外，脱位组根据第二趾偏斜方向分为3个亚组：M组（内侧型）、N组（中立型）和L组（外侧型）。
研究组的IPA和2MDA显著大于对照组。通过多重比较分析，IMA在M组最大，在L组最小。N组的IPA小于L组，2MDA大于L组。L组的HVA和MAA最大，L组的MPD最小。
与单纯拇外翻相比，伴有拇外翻的第二跖趾关节脱位患者拇趾间关节内翻更大，第二跖骨更倾斜。第二趾根据足部形态向不同方向偏斜。
III级，回顾性比较研究。
