Evaluation and Significance of Mortise Instability in Supination External Rotation Fibula Fractures: A Review Article.

Evaluation and management of ankle fractures has progressed in parallel to an evolving understanding of ankle stability. While stability of the mortise had historically been attributed to the lateral malleolus, Lauge-Hansen's contributions followed by multiple other investigations increased the emphasis on the significance of medial-sided injury in destabilizing the mortise. As the importance of the deltoid ligament has been elucidated, the means of assessing ligamentous incompetence and the prognostic significance of an unstable mortise continue to be defined. LEVEL OF EVIDENCE: Level V, expert opinion.

A cadaver study revisiting the original methodology of Lauge-Hansen and a commentary on modern usage.

BACKGROUND: The study by Lauge-Hansen published in the Archives of Surgery in 1950 still stands as the seminal work for our understanding of the pathomechanics of ankle fractures. The purpose of the present study was to recreate Lauge-Hansen's experiments for the supination-external rotation (SER) fracture mechanism and to determine whether the predicted sequence of osseous and soft-tissue injury is reproducible on the basis of his originally described methodology. METHODS: Ten fresh-frozen cadaver specimens amputated above the knee were utilized. The foot was axially loaded in a position of neutral dorsiflexion and supination. External rotation was applied manually in accordance with Lauge-Hansen's description until osseous and/or soft-tissue injury occurred. Fluoroscopic images were made and anatomic dissection was performed. RESULTS: Although several specimens exhibited findings consistent with certain stages of the SER injury pattern, no specimen demonstrated the complete sequence of predicted osseous and soft-tissue injury. CONCLUSIONS: Loading cadaver specimens with an SER mechanism utilizing a methodology similar to that in the original experiments by Lauge-Hansen does not reliably produce the sequence of osseous and soft-tissue injury predicted by Lauge-Hansen.

Correlation of AO and Lauge-Hansen classification systems for ankle fractures to the mechanism of injury.

BACKGROUND: Our aim was to assess whether the Lauge-Hansen (LH) and the Muller AO classification systems for ankle fractures radiographically correlate with in vivo injuries based on observed mechanism of injury. METHODS: Videos of potential study candidates were reviewed on YouTube.com. Individuals were recruited for participation if the video could be classified by injury mechanism with a high likelihood of sustaining an ankle fracture. Corresponding injury radiographs were obtained. Injury mechanism was classified using the LH system as supination/external rotation (SER), supination/adduction (SAD), pronation/external rotation (PER), or pronation/abduction (PAB). Corresponding radiographs were classified by the LH system and the AO system. RESULTS: Thirty injury videos with their corresponding radiographs were collected. Of the video clips reviewed, 16 had SAD mechanisms and 14 had PER mechanisms. There were 26 ankle fractures, 3 nonfractures, and 1 subtalar dislocation. Twelve fractures with SAD mechanisms had corresponding SAD fracture patterns. Five PER mechanisms had PER fracture patterns. Eight PER mechanisms had SER fracture patterns and 1 had SAD fracture pattern. When the AO classification was used, all 12 SAD type injuries had a 44A type fracture, whereas the 14 PER injuries resulted in nine 44B fractures, two 44C fractures, and three 43A fractures. CONCLUSION: When injury video clips of ankle fractures were matched to their corresponding radiographs, the LH system was 65% (17/26) consistent in predicting fracture patterns from the deforming injury mechanism. When the AO classification system was used, consistency was 81% (21/26). The AO classification, despite its development as a purely radiographic system, correlated with in vivo injuries, as based on observed mechanism of injury, more closely than did the LH system. LEVEL OF EVIDENCE: Level IV, case series.

A novel methodology for the study of injury mechanism: ankle fracture analysis using injury videos posted on YouTube.com.

PURPOSE: An inherent deficiency in the understanding of the biomechanics of fractures is the reliance on cadaveric or other nonphysiological injury models resulting from the prohibitive ethical and practical considerations of conducting injury studies in live participants. We describe a novel methodology for studying injury mechanisms using in vivo injury videos obtained from Youtube.com demonstrating injuries as they occur in real time and correlating them with the resulting injury radiographs. METHODS: Over 1000 video clips of potential ankle fractures were assessed for clear visualization of the mechanism of injury, including the foot position and deforming force. Candidate videos were selected if the mechanism of injury was classifiable by those described by Lauge-Hansen and there appeared to be a significant mechanism to likely cause fracture. X-rays were then requested from the individuals posting the video clips. Videos and x-rays were reviewed and classified using the Lauge-Hansen system in a blinded manner. The deforming mechanism in the video clips was classified as supination external rotation, supination adduction (SAD), pronation external rotation (PER), or pronation abduction. X-ray fracture patterns were similarly classified. RESULTS: Two hundred forty videos were selected and individuals posting the videos were contacted. Of 96 initial positive responses, we collected 15 videos with their corresponding radiographs. Eight had SAD-deforming trauma and seven had PER-deforming trauma as appreciated in the videos. There were 12 true ankle fractures. All five fractures judged by video to be SAD injuries resulted in a corresponding SAD pattern radiographic ankle fractures. Of the seven fractures judged by video to be PER injuries, only two resulted in PER pattern radiographic ankle fractures. Five PER injuries resulted in supination external rotation ankle fracture patterns. CONCLUSION: Our series shows that when in vivo injury videos are matched to their corresponding x-rays, the Lauge-Hansen system is only 58% overall accurate in predicting fracture patterns from deforming injury mechanism as pertaining to SAD and PER injury mechanisms. All SAD injuries correlated but only 29% of PER injuries resulted in a PER fracture pattern. This study illustrates the ethical and practical difficulties of using public access Internet YouTube videos for the study of injury dynamics. The current case series illustrates the method's potential and may lead to future research analyzing the validity of the Lauge-Hansen classification system as applied to in vivo injuries.