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.

High rates of vitamin D insufficiency among patients presenting for total knee arthroplasty.

Widely varying prevalence of vitamin D deficiency has been reported in patients presenting for total knee arthroplasty (TKA). The primary aim of this study was to determine vitamin D levels in TKA patients and to compare to patients already routinely evaluated for vitamin D levels, patients with fragility fractures of the distal radius (DRF). There is significant overlap between patients presenting for TKA and with DRF, both in terms of medical comorbidities and overall health status, making these populations suitable comparative cohorts. Wefound that all patients presenting for TKA consultation had vitamin D insufficiency and 33% had vitamin D deficiency, compared to only 37% and 14% in the DRF cohort, a patient population routinely evaluated for vitamin D due to the high risk of deficiency. Furthermore, patients with DRF had higher levels of vitamin D before (38 ± 16 vs. 23 ± 5) and after vitamin D supplementation (39 ± 17 vs. 33 ± 10), suggesting that patients presenting for TKA are at even higher risk of vitamin D insufficiency than patients presenting with DRF. Reassuringly, supplementation successfully corrected 39.0% and 55.8% of patients in the DRF and TKA cohorts, respectively.