Incidence of Vacuum Phenomenon Related Intra-articular or Subfascial Gas Found on Computer-Assisted Tomography (CT) Scans of Closed Lower Extremity Fractures.

OBJECTIVES: To determine the incidence of vacuum phenomenon related intra-articular or subfascial gas found on computer-assisted tomography (CT) scans of closed lower extremity fractures.

DESIGN: Retrospective Review.

SETTING: Level I Trauma Center.

PATIENTS/PARTICIPANTS: A total of 153 patients with closed lower extremity fractures.

INTERVENTION: CT scans of identified individuals were reviewed for the presence or absence of gaseous accumulations.

MAIN OUTCOME MEASUREMENTS: The presence or absence of gas on CT.

RESULTS: Twenty seven (17.6%) of the 153 fractures were found to have intra-articular or subfascial gas on CT despite clear documentation, indicating a closed injury with no significant skin compromise. Of the intra-articular fractures (OTA/AO 33B/C, 41B/C and 43B/C), 20% (23 of 113) were found to have gas on CT. All cases were associated with fracture of the tibia (P = 0.002).

CONCLUSIONS: Computed tomography demonstrated the presence of intra-articular or subfascial gas in 17.6% (27/153) of closed lower extremity fractures and in 20% (23/113) of closed intra-articular fractures. The possibility of vacuum phenomenon must be considered when using this imaging modality as the confirmatory test for open intra-articular fracture or traumatic arthrotomy.

LEVEL OF EVIDENCE: Level IV.