The First Tarsometatarsal Joint in Lisfranc Injuries

Abstract

Background: Lisfranc injuries are among the most debilitating injuries to the foot. Characterization of first tarsometatarsal (TMT) joint involvement in Lisfranc injuries is limited. Multiple studies have indicated that this joint is damaged in a variety of Lisfranc injury patterns, but there is sparse information regarding how often and in what form. Methods: A retrospective review was performed of operative Lisfranc fractures from 2010 to 2020 with patients identified by Combined Procedural Terminology codes. Hardcastle and Myerson Lisfranc injury classifications and computed tomography and radiograph characterizations of the first TMT joint were evaluated by 3 foot and ankle fellowship–trained orthopaedic surgeons. Radiographic characteristics were collected. Light’s kappa coefficient evaluated interrater reliability for injury classification. Injury mechanism and Lisfranc classification effects on the first TMT joint were further assessed using inferential statistics. Results: Of 71 patients with a Lisfranc injury of which 37 (52%) were high energy, 61 (86%) showed radiographic evidence of first TMT joint injury. A fragment was present in the TMT articular surface in 33 (47%) with median size = 8.7 mm and medial capsular avulsion in n = 25 (35%). Forty-eight patients (68%) had medial/lateral TMT joint incongruence ≥2 mm (median overhang = 4 mm), 21 (30%) had dorsal/plantar incongruence (median overhang = 6 mm). Angulation of TMT articular surfaces ≥5 degrees on the transverse/anteroposterior plane occurred in n = 32 (45%) and in n = 12 (17%) on the sagittal/lateral plane, which significantly differed between classifications ( P = .020). Conclusion: The overwhelming majority of Lisfranc midfoot injuries seen at our tertiary referral center had imaging evidence of damage to the first TMT joint (86%), and the incidence may be higher. The most common patterns of first TMT joint involvement we found were joint incongruity, articular surface fractures, angulation of the articular surfaces, and medial capsular ligament avulsion fractures. A better understanding of injuries to the first TMT joint can help orthopaedic surgeons with diagnosis.

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

“…The advantage of CT is in the diagnosis of microfractures and translocations. In the study by Wong et al (34), the most common types of injury in first-ray injuries were joint dislocations and microfractures, which further supported the diagnostic utility of CT in first-ray injuries. However, in the second and cuneiform rays, the CT diagnosis of subtle Lisfranc injuries was inferior to MRI.…”

Management of Lisfranc Injuries

“…Although not extensively studied in the literature, it may serve as an adjunct in the diagnosis of subtle injuries and/or in confirming accurate reduction intraoperatively. Injury to the first TMTJ, including articular damage, fracture, and/or joint incongruity, may occur in up to 86% of cases and has been overlooked previously 34 . Fractures of the second metatarsal base with no evidence of radiographic instability at the Lisfranc joint are commonly (but incorrectly) interpreted as Lisfranc injuries and are treated conservatively.…”

Letter Regarding: Functional Outcomes After High-Energy Lisfranc Injuries

“…The presence of high- vs low-energy mechanism does not reliably predict injury pattern. We recently reported on midfoot injuries 5 ; review of our cohort revealed that 35% of homolateral dislocations arose from ground-level falls and 33% of B2 (Lisfranc interval diastasis) were attributable to high-energy mechanisms (motor vehicle crash, crush, and fall from height). This method of characterizing midfoot injury is not perfect, but our observation suggests that sorting injuries by description of mechanism can be imprecise.…”