My name is Junaid Amir, and welcome to our presentation on the occurrence of parallelism or the first and second ray in mid-foot fracture dislocations, a review of 410 cases. So we start the presentation with the following quote from Lau et al., where in their 2017 review, they identified that approximately 20% of cases of lisfranc fracture dislocations were misdiagnosed. Compounded with this issue of misdiagnosis is this paper presented in 2004 by Calder et al., which displayed 46 patients and a delay of diagnosis of more than six months was associated with poorer outcomes. Now that can obviously mean clear functional and medical legal implications for both the patient and the health provider. So in terms of identifying lisfranc injury, well, the following paper written by Rick et al. in 2022 identified patients who were surgically confirmed to have lisfranc injuries and were retrospectively analysed with their weight-bearing radiographs, and the following measurements were identified. Just to expand on it further, of course, you have the flex sign in the base of the metatarsal, intermetatarsal fat pad sign, and the tarsometatarsal 2 subluxation. Additionally, common identifiers are dorsal step-off sign and the intercuneiform diastasis. However, despite this multitude of identifiers for lisfranc injuries, the following paper from Gill et al. explains that the assessment of intermetatarsal angle and observation of metatarsal parallelism is an easy-to-recognise sign which is easily taught and reproducible. So our aim was to explore the prevalence of parallelism in midfoot injuries and the associated features. So we defined parallel as the intermetatarsal angle of less than six degrees. We included four centres and we took 10 years' worth of data for surgically treated midfoot fractures, we assessed them using PACS and we analysed our stats using SPSS. Alongside the parallelism, we also assessed the location of the injury in relation to their column, the number of columns involved and the severity of the injury with regards to no joint involvement, ligamentous or simple or comminuted fracture. So what did we find? Of our 410 cases, 398 had non-weight bearing views, 155 had weight bearing views and the incidence of parallelism between the non-weight bearing and the weight bearing views was similar. Our average intermetatarsal angle was 4.52 degrees in the parallel set and 9.37 in the non-parallel set. Following our assessment of the incidence of parallelism, we assessed the association of this phenomenon with the number of columns of the foot involved. Our primary finding was that with the increasing amount of column involvement, there was an increase in the observed parallelism. Breaking down our analysis further, in comparing the location of the column involvement, we can identify that lateral column injuries had a significantly higher proportion of observed parallelism on radiographs compared to central and medial. Finally, assessing the type of injury, we were unable to identify a statistically significant difference in bony or ligamentous injuries and the proportion of observed parallelism. To conclude, multi-column and specifically lateral column midfoot injuries have a significantly higher proportion of observed parallelism based off radiographic evidence. Despite this, however, most patients did not display evidence of parallelism. However, intermetatarsal angle measurement and parallelism is a quick and simple measurement tool which may be of benefit on specific types of midfoot injuries. Thank you.

parallelism

mid-foot fracture dislocations

misdiagnosis

delayed diagnosis

lisfranc injuries