Department of Orthopaedic Surgery, Foot and Ankle Research and Innovation Laboratory (FARIL), Massachusetts General Hospital, Harvard Medical School, Boston, USA; Department of Orthopaedic Surgery, Amsterdam UMC, University of Amsterdam, Amsterdam Movement Sciences, Meibergdreef 9, Amsterdam, the Netherlands; Academic Center for Evidence Based Sports Medicine (ACES), Amsterdam, the Netherlands; Amsterdam Collaboration for Health and Safety in Sports (ACHSS), International Olympic Committee (IOC) Research Center Amsterdam UMC, Amsterdam, the Netherlands.
Department of Orthopaedic Surgery, Foot and Ankle Research and Innovation Laboratory (FARIL), Massachusetts General Hospital, Harvard Medical School, Boston, USA.
Injury. 2022 Jun;53(6):2326-2332. doi: 10.1016/j.injury.2022.02.044. Epub 2022 Feb 22.
Ligamentous Lisfranc instability is commonly missed on unilateral radiographs. However, measurement protocols for bilateral weightbearing radiographs have not been standardized. The primary aim of this study was to investigate the optimal cut-off values for diagnosing Lisfranc instability by evaluating the side-to-side differences of preoperative bilateral weightbearing radiographs among patients with surgically-confirmed ligamentous Lisfranc instability. A secondary aim was to investigate whether the midfoot measurements for detecting Lisfranc injury could also be used in patients with a pre-existing bilateral Hallux Valgus (HV) deformity by evaluating whether the Lisfranc measurements could be affected by a foot deformity as HV.
Patients who underwent surgical repair of ligamentous Lisfranc instability, as well as a separate cohort with bilateral hallux valgus deformity, were included in this multicenter retrospective cohort study. A standardized radiographic measurement protocol was used to assess the midfoot and a receiver operator correlation (ROC) analysis was used to identify the optimal cut-off value for measurements. Interclass Correlation (ICC) scores were calculated to assess the interrater reliability of the Lisfranc area measurement.
Forty-seven patients were included in the Lisfranc group with a mean age of 33 (± 15) years and 25 patients were included in the HV group with a mean age of 51 (± 15) years. For the Lisfranc group, measurements that demonstrated a significant side-to-side difference included; increased C1M2 diastasis of 2.4 mm (± 1.4, P<0.001), increased C1M2 surface area of 24 mm (± 15, P<0.001), C2M2 malignment by 1.7 mm (± 1.2, P<0.001), second tarsometatarsal joint dorsal step-off sign by 0.8 mm (± 0.7, P<0.001), and arch height by 2.5 mm (± 6.4, P<0.048), all greater on the injured side. In the HV group, side-to-side measurements were not significantly different. There was no significant difference comparing the M1M2 measurement in the HV group with the injured (P = 0.16) or uninjured (P = 0.08) foot in the Lisfranc group. The optimal cut-off points were between the injured and uninjured foot in the Lisfranc group were 2.1 mm for C1M2 diastasis, 0.7 mm for the C2M2 alignment, and 30 mm for the C1M2 surface area. The ICC-score for the second C1M2 area measurement was 0.88.
Bilateral foot weightbearing radiographs can effectively diagnose ligamentous Lisfranc instability using a standardized measurement protocol. Malalignment of the medial aspect of the second metatarsal base ≥0.3 mm relatively to the intermediate cuneiform offers a high sensitivity, and distance ≥2.1 mm between the second metatarsal base and the medial cuneiform has a high specificity. Intermetatarsal distance between the first and second metatarsal base has a low sensitivity and specificity and should not be used in solitary for diagnosis.
Level III, retrospective comparative study.
在单侧 X 光片上，通常会错过 Ligamentous Lisfranc 不稳定性。然而，对于双侧负重 X 光片的测量方案尚未标准化。本研究的主要目的是通过评估手术证实 Ligamentous Lisfranc 不稳定患者术前双侧负重 X 光片的侧别差异，研究诊断 Lisfranc 不稳定的最佳截断值。次要目的是通过评估 Lisfranc 测量是否会受到双侧 Hallux Valgus（HV）畸形的影响，研究用于检测 Lisfranc 损伤的中足测量值是否也可用于存在双侧 HV 畸形的患者，因为 HV 是一种足部畸形。
本多中心回顾性队列研究纳入了接受 Ligamentous Lisfranc 不稳定手术修复的患者以及单独的双侧 HV 畸形队列。使用标准化的 X 光测量方案评估中足，并使用接受者操作特征相关（ROC）分析确定测量的最佳截断值。计算组内相关系数（ICC）评分，以评估 Lisfranc 区域测量的组内信度。
Lisfranc 组纳入 47 例患者，平均年龄为 33（±15）岁；HV 组纳入 25 例患者，平均年龄为 51（±15）岁。对于 Lisfranc 组，显示出显著侧别差异的测量值包括：C1M2 间隙增加 2.4mm（±1.4，P<0.001），C1M2 表面积增加 24mm（±15，P<0.001），C2M2 错位增加 1.7mm（±1.2，P<0.001），第二跖骨间关节背侧台阶征增加 0.8mm（±0.7，P<0.001），和足弓高度增加 2.5mm（±6.4，P<0.048），所有这些均发生在受伤侧。HV 组的侧别测量值无明显差异。HV 组的 M1M2 测量值与 Lisfranc 组受伤（P=0.16）或未受伤（P=0.08）脚的 M1M2 测量值之间无显著差异。Lisfranc 组的最佳截断点为 C1M2 间隙为 2.1mm，C2M2 对线为 0.7mm，C1M2 表面积为 30mm。第二个 C1M2 区域测量的 ICC 评分为 0.88。
使用标准化的测量方案，双侧足部负重 X 光片可有效诊断 Ligamentous Lisfranc 不稳定性。与中间楔骨相比，第二跖骨基底部内侧的错位≥0.3mm 具有较高的敏感性，而第二跖骨基底部与内侧楔骨之间的距离≥2.1mm 具有较高的特异性。第一和第二跖骨基底之间的跖骨间距离敏感性和特异性均较低，不应用于单独诊断。
III 级，回顾性比较研究。
