Lisfranc injury: Refined diagnostic methodology using weightbearing and non-weightbearing radiographs

Jan De Bruijn,Noortje C Hagemeijer,Quinten G.H Rikken,Jad S Husseini,Jirawat Saengsin,Gino M.M.J Kerkhoffs,Gregory Waryasz,Daniel Guss,Christopher W Digiovanni

doi:10.1016/j.injury.2022.02.040

Jan De Bruijn, Noortje C Hagemeijer + Show 7 more

Open Access

https://doi.org/10.1016/j.injury.2022.02.040

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Abstract

BackgroundTo compare diagnostic parameters for Lisfranc instability on WB and NWB radiographs and to assess the inter-observer reliability of a standardized diagnostic protocol. Patients and methodsPatients who had undergone surgical treatment for subtle, purely ligamentous Lisfranc injury with both WB and NWB post-injury, pre-surgery films (n = 26) were included in this multicentre, retrospective comparative study. Also included was a control group (n = 26) of patients with isolated fifth metatarsal avulsion fractures who similarly had both WB and NWB films. Multiple midfoot distance and alignment measurements were used to evaluate the Lisfranc joint on both WB and NWB views. To evaluate interobserver reliability, measurements were made by two independent observers across a cohort subset. ResultsWhen comparing the NWB views between groups, only C1M2 (medial cuneiform- second metatarsal) distance was found to be significantly larger (∆ = 1.35 mm, p <0.001) for Lisfranc injuries. Most notably, C2M2 (Intermediate cuneiform – second metatarsal) step off—caused by lateral translation of the second metatarsal base—was not significantly different (∆ = 0.39 mm, p = 0.101) between Lisfranc patients and controls. On WB views, Lisfranc patients had significantly larger changes to C1M2 distance and C2M2 step-off as compared to controls (∆ = 2.97 mm, p <0.001 and ∆ = 1.98 mm, p <0.001 respectively). M1M2 (first to second intermetatarsal) distance was not significantly different between patients and controls in WB films. Within the cohort of ligamentous Lisfranc patients, C1M2 distance and C2M2 step-off were significantly larger in WB when compared to NWB films (∆ = 1.77 mm, p <0.001 and ∆ = 1.58 mm, p <0.001 respectively). For these parameters, inter-observer reliability scores (ICC) of >0. 90 were found when interpreting WB radiographs and ICC's ranging between 0.61 and 0.80 were found when interpreting NWB radiographs. ConclusionUsing WB imaging for diagnosing subtle Lisfranc instability reveals larger diastasis in the tarsometatarsal joint and has a higher interobserver reliability compared to NWB imaging. Clinical concern for subtle or occult Lisfranc instability in any patient should therefore trigger WB radiographic assessment since such injuries may be missed on NWB views.

Highlights

On NWB radiographs the following measurements were significantly larger in the Lisfranc group as compared to the control group: Medial cuneiform-second metatarsal (C1M2) distance, First- to second metatarsal (M1M2) distance, and dorsal step-off at the second TMT joint
To assess any difference from the effect of weightbearing on Lisfranc joint measurements between patient groups, delta values were calculated between non-weightbearing and weightbearing radiographs within each group for comparison of the measurements that we identified to be affected by Lisfranc injury
While heightened awareness and careful physical exam are critical to this end, definitive diagnosis of Lisfranc instability generally hinges on an imaging modality

Summary

Introduction

Mean ± SD Male BMI, mean ± SD Caucasian Diabetes Peripheral Neuropathy Smoking. Former Current Injured side: right Deformity measurements Intermetatarsal angle, mean (95%CI) Hallux Valgus angle, mean (95%CI) Talonavicular coverage angle, mean (95%CI) Calcaneal pitch, mean (95%CI) 1TMT – Meary’s angle, mean (95%CI). The optimal radiographic parameters that should be used to diagnose Lisfranc instability on weight bearing (WB) and NWB radiographs remain unclear, especially as instability becomes increasingly subtle [9,10,11]. Studies reporting radiographic landmarks are inconsistent in their measuring methods, resulting in questionable generalizability of established cut-off values. The aims of this study, were to: 1) Compare diagnostic parameters for Lisfranc instability on WB and NWB radiographs and, 2) To establish and assess inter-observer reliability of a standardized diagnostic protocol. The primary null hypothesis was that there would be no radiographic distance measurement differences between WB and NWB films that would prove predictive of Lisfranc injury. A secondary null hypothesis was that there would be no measurement differences between feet with Lisfranc injuries and those of healthy controls for any radiographic parameter

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