Reliability of various diastasis measurement methods on weightbearing radiographs in patients with subtle Lisfranc injuries.

Objective: This study aimed to evaluate the reliability of the diastasis measurements between the medial cuneiform and the second metatarsal on weightbearing radiography.

Materials And Methods: We retrospectively examined 18 patients who underwent open surgery for subtle Lisfranc injuries. Preoperative weightbearing radiography of the affected and unaffected feet was evaluated in all patients. The diastasis between the medial cuneiform and the second metatarsal was measured in both feet using the following four methods: diastasis between parallel lines, distal point diastasis, middle point diastasis, and proximal point diastasis. Intraclass correlation coefficients with consistency of agreement were calculated to evaluate inter- and intraobserver reliability.

Results: The intra- and interobserver reliabilities of all four methods were good. Intraclass correlation coefficients for intraobserver reliability ranged from 0.87 to 0.93. Those for interobserver reliability ranged from 0.81 to 0.91.

Conclusions: The reliabilities of the diastasis measurement methods between the medial cuneiform and the second metatarsal on weightbearing radiography were good. Measuring the diastasis between the medial cuneiform and the second metatarsal on weightbearing radiography is useful in evaluating subtle injuries when uniform measurement methods are used.