Prospective intraoperative syndesmotic evaluation during ankle fracture fixation: stress external rotation versus lateral fibular stress.
OBJECTIVE
We hypothesized that the method of stress external rotation more accurately reproduces the mechanism of injury, and therefore this diagnostic method more likely detects ankle instability than the fibular stress examination.


METHODS
Prospective cohort comparison study.


METHODS
Level 1 trauma center.


METHODS
Twenty-eight consecutive patients with unstable ankle fractures presenting within 7 days from the time of injury. Previous ankle surgical history or age younger than 18 years was excluded.


METHODS
Stress external rotation and lateral fibular stress examination was performed intraoperatively.


METHODS
Radiographic measurement of the tibiofibular clear space, tibiofibular overlap, and medial clear space were recorded.


RESULTS
After normalization of the fluoroscopic measurements, there was no difference in detecting changes in tibiofibular clear space or tibiofibular overlap. However, there was a significant difference in detecting medial clear space widening with stress external rotation. Compared with lateral fibular stress, stress external rotation demonstrated a 35% increase (P < 0.05) in medial clear space widening. This difference correlates with the 1-2-mm difference of additional widening with stress external rotation.


CONCLUSIONS
Untreated instability impacts patient outcomes. The difference in widening with stress external rotation was significantly greater than lateral fibular stress and appreciable on standard fluoroscopic views. Stress external rotation radiographs are a more reliable indicator of mortise instability than traditional lateral fibular stress.


METHODS
Diagnostic Level IV. See Instructions for Authors for a complete description of levels of evidence.
*Department of Orthopaedic Surgery, University of Maryland School of Medicine, Baltimore, MD; and †Department of Orthopaedic Surgery, University of Pennsylvania School of Medicine, Philadelphia, PA.
Paul E
PE
Matuszewski
Derek
D
Dombroski
J Todd R
JT
Lawrence
John L
JL
Esterhai
Samir
S
Mehta
D000328:Adult; D000368:Aged; D064386:Ankle Fractures / Q000175:diagnosis* / Q000601:surgery*; D000843:Ankle Joint; D005260:Female; D005360:Fibula; D005593:Fracture Fixation, Internal / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods*; D015588:Observer Variation; D010808:Physical Examination / Q000379:methods*; D016059:Range of Motion, Articular; D015203:Reproducibility of Results; D012399:Rotation; D012680:Sensitivity and Specificity; D013314:Stress, Mechanical; D016896:Treatment Outcome; D055815:Young Adult