Inter- and intraobserver reliability of non-weight-bearing foot radiographs compared with CT in Lisfranc injuries

Abstract

Background Injury of the tarsometatarsal (TMT) joint complex, known as Lisfranc injury, covers a wide range of injuries from subtle ligamentous injuries to severely displaced crush injuries. Although it is known that these injuries are commonly missed, the literature on the accuracy of the diagnostics is limited. The diagnostic accuracy of non-weight-bearing radiography (inter-or intraobserver reliability), however, has not previously been assessed among patients with Lisfranc injury. Methods One hundred sets of foot radiographs acquired due to acute foot injury were collected and anonymised. The diagnosis of these patients was confirmed with a CT scan. In one-third of the radiographs, there was no Lisfranc injury; in onethird, a nondisplaced (< 2 mm) injury; and in one-third, a displaced injury. The radiographs were assessed independently by three senior orthopaedic surgeons and three orthopaedic surgery residents. Results Fleiss kappa (κ) coefficient for interobserver reliability resulted in moderate correlation κ = 0.50 (95% CI: 0.45-0.55) (first evaluation) and κ = 0.58 (95% CI: 0.52-0.63) (second evaluation). After three months, the evaluation was repeated and the Cohen's kappa (κ) coefficient for intraobserver reliability showed substantial correlation κ = 0.71 (from 0.64 to 0.85). The mean (range) sensitivity was 76.1% (60.6-92.4) and specificity was 85.3% (52.9-100). The sensitivity of subtle injuries was lower than severe injuries (65.4% vs 87.1% p = 0.003). Conclusions Diagnosis of Lisfranc injury based on non-weight-bearing radiographs has moderate agreement between observers and substantial agreement between the same observer in different moments. A substantial number (24%) of injuries are missed if only non-weight-bearing radiographs are used. Nondisplaced injuries were more commonly missed than displaced injuries, and therefore, special caution should be used when the clinical signs are subtle. Level of evidence III.

The First Tarsometatarsal Joint in Lisfranc Injuries

“…The Hardcastle Myerson classification was derived from work originally published in French in 1909. 24 It has been shown to have moderate interrater reliability 16,22,29 but has not gained traction as an effective tool in predicting out come. 30,34 Our work evaluated reliability of the Hardcastle Myerson system and found commensurate interrater reliability to previously reported work.…”

Outcomes after nonoperatively treated non-displaced Lisfranc injury: a retrospective case series of 55 patients

“…In all of these previous studies, the diagnosis of the injury was based on plain radiographs, and the evaluation of the outcomes was conducted without valid outcome measures [4,5,8,22,34]. However, when the diagnosis is based solely on plain radiographs, there is a possibility that injuries that would have benefited from more cautious treatment and also injuries that would not heal with nonoperative treatment, and, therefore, require operative treatment, are missed [26].…”

“…Multiple methods have been suggested to detect the instability, such as weightbearing radiographs and stress testing under fluoroscopy [22,29]. Recent studies have, however, raised concerns about whether weightbearing radiographs have weak sensitivity and specificity to detect the instability [15,26,27]. In addition, the reference method for the evaluation, stress testing under fluoroscopy, has been shown to have low interobserver reliability, and, therefore, is not a practical way to detect the instability [21].…”

“…In addition, the reference method for the evaluation, stress testing under fluoroscopy, has been shown to have low interobserver reliability, and, therefore, is not a practical way to detect the instability [21]. Hence, radiograph-based modalities and stress testing are not efficient, and computed tomography (CT) has been suggested to be the method of choice [10,12,26,27].…”

Comparing bilateral feet computed tomography scans can improve surgical decision making for subtle Lisfranc injury

“…They are regarded as midfoot sprains could arise from low-energy trauma [22,33]. Nonweightbearing (NWB) radiographs cannot detect in up to 24-50% of patients, and in the diastasis between the medial cuneiform and the second metatarsal (C1M2) [22,27]. Therefore, weightbearing (WB) radiographs are suggested to identify SLIs; however, patients are unable to bear full weight because of pain, leading to an inconclusive study [45].…”