From the Department of Diagnostic Imaging, National University Hospital, 5 Lower Kent Ridge Rd, 119074 Singapore (J.T.P.D.H.); Yong Loo Lin School of Medicine, National University of Singapore, Singapore (J.T.P.D.H.); Department of Radiology, VA San Diego Healthcare System, San Diego, Calif (S.M.S., G.M.B., C.B.C.); Department of Radiology, San Diego Medical Center, University of California, San Diego, Calif (B.K.H., C.B.C.); Department of Radiology, Hospital do Coração (HCor) and Teleimagem, São Paulo, Brazil (H.G.B.); and Universidade Federal de São Paulo, São Paulo, Brazil (UNIFESP) and Hospital Beneficência Portuguesa de São Paulo, São Paulo, Brazil (D.A.L.G.).
Radiographics. 2020 Jul-Aug;40(4):1107-1124. doi: 10.1148/rg.2020190145. Epub 2020 May 15.
The first metatarsophalangeal joint (MTPJ) is vital to the biomechanics of the foot and supports a weight up to eight times heavier than the body during athletic activities. The first MTPJ comprises osseous and cartilaginous surfaces along with a complex of supporting structures, including the dorsal extensor tendons, collateral ligaments, and a plantar plate complex. In contradistinction to the lesser MTPJ plantar plates, a single dominant fibrocartilaginous capsular thickening does not exist at the first MTPJ. Instead, the plantar plate complex comprises a fibrocartilaginous pad that invests the hallux sesamoids and is inseparable from the plantar capsule, the intersesamoid ligament, paired metatarsosesamoid and sesamoid phalangeal ligaments (SPLs), and the musculotendinous structures. Acute injury at the first MTPJ is typically secondary to forced hyperextension-turf toe-and can involve multiple structures. During hyperextension, the resulting forces primarily load the distal SPLs, making these structures more susceptible to injury. SPL injuries are best seen in the sagittal plane at MRI. Radiography can also aid in diagnosis of full-thickness SPL tears, demonstrating reduced sesamoid excursion at lateral dorsiflexed (stress) views. Hallux valgus is another common condition, resulting in progressive disabling deformity at the first MTPJ. Without appropriate treatment, first MTPJ injuries may progress to degenerative hallux rigidus. The authors detail the anatomy of the first MTPJ in cadaveric forefeet by using high-resolution 3-T and 11.7-T MRI and anatomic-pathologic correlation. Injuries to the plantar plate complex, collateral ligaments, and extensor mechanism are discussed using clinical case examples. RSNA, 2020.
第一跖趾关节（MTPJ）对于足部的生物力学至关重要，在运动活动中支撑的重量可达体重的 8 倍以上。第一 MTPJ 由骨和软骨表面以及一系列支持结构组成，包括背侧伸肌腱、侧副韧带和跖板复合体。与较小的 MTPJ 跖板不同，第一 MTPJ 不存在单一主导的纤维软骨囊增厚。相反，跖板复合体包括一个纤维软骨垫，它包裹着大脚趾籽骨，并且与足底囊、中间籽骨韧带、成对的跖骨籽骨和籽骨跖骨韧带（SPL）以及肌肉腱结构不可分割。第一 MTPJ 的急性损伤通常继发于强制过度伸展-网球趾-并且可能涉及多个结构。在过度伸展时，产生的力主要加载于远端 SPL，使这些结构更容易受伤。SPL 损伤在 MRI 的矢状面最佳可见。放射线照相术也有助于诊断全层 SPL 撕裂，在侧向背屈（应力）视图中显示籽骨活动度降低。拇外翻是另一种常见疾病，导致第一 MTPJ 进行性致残性畸形。如果没有适当的治疗，第一 MTPJ 损伤可能进展为退行性僵硬拇。作者通过使用高分辨率 3-T 和 11.7-T MRI 以及解剖病理学相关性详细描述了尸体前脚的第一 MTPJ 解剖结构。使用临床病例示例讨论了跖板复合体、侧副韧带和伸肌机制的损伤。RSNA，2020 年。
