The Emerging Role of Automation, Measurement Standardization, and Artificial Intelligence in Foot and Ankle Imaging: An Update

The utility of point-of-care dynamic ultrasonography for the diagnosis of subtle isolated ligamentous Lisfranc injuries: a cadaveric study

OBJECTIVES

To assess if Lisfranc injury can be detected by US with and without abduction stress.

METHODS

Eight cadaveric feet were obtained. The following measurements were obtained in the uninjured feet: C1M2 and C1C2 intervals and TMT1 and TMT2 dorsal step-off distances. Measurements were obtained both with and without abduction stress using ultrasound. The injury model was created by transecting the Lisfranc ligament complex, after which the observers performed the measurements again. Statistical analysis was used to identify differences between intact and injured models, to determine diagnostic cut-off values for identifying Lisfranc injuries, and to assess interobserver/intraobserver reliability.

RESULTS

There was a significant difference in the mean C1M2 interval, both with and without abduction stress, between the intact and torn Lisfranc ligament (p < 0.001). A C1M2 interval with stress of > 2.03 mm yielded 81% sensitivity and 72% specificity for Lisfranc disruption. There was no significant difference in the mean C1C2 interval of the torn versus intact Lisfranc ligament without stress (p = 0.10); however, the distance was significantly different with the application of stress (p < 0.001). The C1C2 interval of > 1.78 mm yielded 72% sensitivity and 69% specificity for Lisfranc injury under stress. There were no significant differences in the mean TMT1 or TMT2 dorsal step-off measurements between the intact and torn Lisfranc ligaments. All observers showed good intraobserver ICCs. The interobserver ICCs for all measurements were good or excellent, except for TMT1, which was moderate.

CONCLUSION

Ultrasonography is a promising point-of-care imaging tool to detect Lisfranc ligamentous injuries when measuring C1M2 and C1C2 distances under abduction stress.

Effect of sequential burr passes on minimally invasive akin and first metatarsal dorsiflexion osteotomies

BACKGROUND

Minimally invasive surgical (MIS) osteotomies are increasing as a surgical option for treating midfoot and forefoot conditions. This study aimed to evaluate the impact of each burr pass on the degree of correction, gap size, and alignment in MIS Akin and first metatarsal dorsiflexion osteotomies (DFO).

METHODS

MIS Akin and first metatarsal DFO were performed on ten cadaveric specimens. Fluoroscopic measurements included the metatarsal dorsiflexion angle (MDA), dorsal cortical length (MDCL), first phalangeal medial cortical length (PCML) and proximal to distal phalangeal articular angle (PDPAA).

RESULTS

The average decrease in PCML with each burr pass was as follows: 1.53, 1.33, 1.27, 1.23 and 1.13 mm at the 1st to 5th pass, respectively. The MDCL sequentially decreased by 1.80, 1.59, 1.35, 0.75, and 0.60 mm. The MDA consistently decreased, and the PDPAA incrementally became more valgus oriented.

CONCLUSION

On average, a first metatarsal dorsal wedge resection of 4.7 mm and first phalangeal medial wedge resection of 2.9 mm was achieved after 3 and 2 burr passes, respectively. This data may aid surgeons determine the optimal number of burr passes required to achieve the desired patient-specific surgical correction.