Lisfranc fracture-dislocation precipitating acute Charcot arthopathy in a neuropathic diabetic foot: a case report

Comparison of diagnostic performance of X‑ray, CT and MRI in patients with surgically confirmed subtle Lisfranc injuries

The present study aimed to compare the diagnostic performance of three imaging tests: X-ray, computed tomography (CT) and magnetic resonance imaging (MRI), for subtle Lisfranc injuries and three anatomical subtype injuries. The non-weight-bearing X-ray, CT and MRI imaging results of patients with subtle Lisfranc injuries from September 2013 to March 2022 were retrospectively reviewed. Subtle Lisfranc injuries and three anatomical subtypes (first, second and cuneiform rays) were diagnosed based on the surgical reports. The diagnostic performance of X-ray, CT and MRI was compared. The sensitivity (Sn), specificity (Sp), positive predictive value, negative predictive value, area under the receiver operating characteristic curve (AUC) and κ coefficient were reported. A total of 31 patients were included in the study. The correct diagnosis was made in 48.4% (15/31), 87.1% (27/31) and 96.8% (30/31) of patients by X-ray, CT and MRI, respectively. A total of 54 different anatomical injuries were found intraoperatively in all patients, with MRI and CT having high agreement (Sn, 72.2 and 87.0%; κ, 0.69 and 0.78, respectively) and X-ray having a low agreement (Sn, 29.6%; κ, 0.26) with the surgical findings. Regarding the first-ray injuries, CT had the highest Sn (76.9%), Sp (100%) and AUC (0.885) in diagnosing subtle Lisfranc injuries. MRI showed the best Sn (88.5 and 93.3%, respectively) and AUC (0.942 and 0.904, respectively) in both second and cuneiform rays. In conclusion, non-weight-bearing X-rays had poor diagnostic accuracy for subtle Lisfranc injuries and their subtypes. CT was superior to X-rays and MRI in diagnosing first-ray injuries. Although not significantly different from CT in terms of overall diagnosis, MRI was superior to X-ray and CT in diagnosing second and cuneiform-ray injuries.

Fractures and dislocations of the foot and ankle in people with diabetes: a literature review

Diabetes (DM) increases fracture risk, and bone quality depends on type diabetes type, duration, and other comorbidities. Diabetes is associated with a 32% increased relative risk (RR) of total fractures and 24% increased RR of ankle fractures compared with patients without DM. Type 2 DM is associated with a 37% increased RR of foot fractures compared with patients without DM. The incidence of ankle fractures in the general population is 169/100,000 per year, while foot fractures occur less frequently, with an incidence of 142/100,000 per year. Biomechanical properties of bone are negatively impacted by stiff collagen, contributing to the increased risk of fragility fractures in patients with DM. Systemic elevation of proinflammatory cytokines, such as tumor necrosis factor-alpha (TNFα), interleukin-1β (IL-1β), and interleukin 6 (IL-6), impact bone healing in patients with DM. Fractures in patients with DM, can be associated with poorly regulated levels of RANKL (receptor activator of nuclear transcription factor kappa-b ligand) leading to prolonged osteoclastogenesis, and net bone resorption. One of the most salient factors in treating fractures and dislocations of the foot and ankle is to recognize the difference between patients with uncomplicated and complicated DM. Complicated diabetes is defined as 'end organ damage', and for the purposes of this review, includes patients with neuropathy, peripheral artery disease (PAD) and/or chronic renal disease. Uncomplicated diabetes is not associated with 'end organ damage'. Foot and ankle fractures in patients with complicated DM pose challenges, and surgery is associated with increased risks of impaired wound healing, delayed fracture healing, malunion, infection, surgical site infection, and revision surgery. While patients with uncomplicated DM can be treated like patients without DM, patients with complicated DM require close follow-up and robust fixation methods should be considered to withstand the anticipated prolonged healing period. The aims of this review are as follows: (1) to review pertinent aspects of DM bone physiology and fracture healing, (2) to review the recent literature on treatment of foot and ankle fractures in patients with complicated DM, and (3) to provide treatment protocols based on the recent published evidence.

Computational analysis of the clinical presentation of a ligamentous Lisfranc injury

Lisfranc injuries in the midfoot disrupt key arches of the foot which, if left untreated, can progress to pain, dysfunction, and arthritis. A clinical challenge is that 30-40% of Lisfranc injuries are missed in initial evaluations. The objective of this study was to explore different conditions of limb loading that could influence the biomechanics of the Lisfranc joint in a validated computational model. A computational model was created using SolidWorks software to represent the bones and soft tissues of the lower leg and foot. The model was compared to a cadaveric study of healthy and injured Lisfranc joints. The model was then used to simulate weight-bearing radiographs and evaluate how muscle activity and foot position impacted the diastasis of the Lisfranc joint, a key indicator used to diagnose Lisfranc injuries. The computational model was within one standard deviation of the cadaveric study in all measurements for the healthy and injured foot. When simulating weight-bearing radiographs, the presence of muscle activity or inversion/eversion resulted in less joint separation for the model with ligamentous Lisfranc injuries. While previous research has noted that weight-bearing radiographs provide better conditions to assess Lisfranc injuries than nonweight-bearing, this study suggests that in weight-bearing radiographs both altering the position of the foot, possibly due to pain, and the active contraction of the extrinsic flexor muscles can obfuscate indications of a Lisfranc injury.

Diabetic Lisfranc fracture-dislocations and Charcot neuroarthropathy

The goal with Lisfranc fracture-dislocations is to regain joint congruity and reestablish midfoot stability to avoid debilitating posttraumatic arthrosis and chronic pain in the sensate patient. In the diabetic population, dense peripheral neuropathy and/or vascular disease are equally important and may alter the surgical approach to traumatic tarsometatarsal injuries. The initial diagnosis in the diabetic population may be delayed due to subtle radiographic findings and/or patient unawareness of trauma in the insensate foot. Failure to initiate treatment in the early stages of acute diabetic neuropathic Lisfranc injuries can predispose the patient to midfoot instability, potential ulceration, infection, and Charcot neuroarthropathy.