Transitional transverse acetabular fractures: differences between fractures with a large posterio-superior fragment and the inverse T-fracture--a report of 10 unusual cases.
BACKGROUND
Classification of fractures is crucial in decision making and planning of acetabular surgery. Transverse fractures with secondary vertical fracture lines--which constitute either a large posterio-superior fragment (floating dome) or an inverse T with the posterior ileum attached to the axial skeleton--have not been described in detail in the literature.


METHODS
All acetabular fractures at Ullevål University Hospital have been recorded prospectively since 1993 and classified according to Judet/Letournel.


RESULTS
In 10/449 fractures (2%) there was a transverse fracture line through the acetabulum, with an additional vertical fracture line ascending either to the iliac crest or the SI-joint. In 6 of these fractures the vertical line started within the acetabulum, and the posterior part of the ileum with part of the articular surface was attached to the axial skeleton. In 4 fractures the vertical fracture line started posterior to the joint, constituting a very large posterio-superior fragment without any articular surface (a floating dome).


CONCLUSIONS
Open reduction and internal fixation of inverse T-fractures and transverse fractures with a floating dome require different surgical approaches. The latter can be treated through a single approach alone, while the inverse T-fracture may require extensile or combined approaches for adequate reduction and fixation.
Orthopaedic Centre, Ullevål University Hospital, Norway. SteinA.Ovre@ulleval.no
Stein
S
Øvre
Jan Erik
JE
Madsen
Olav
O
Røise
D000077:Acetabulum / Q000000981:diagnostic imaging / Q000293:injuries* / Q000601:surgery; D005593:Fracture Fixation, Internal; D050723:Fractures, Bone / Q000145:classification / Q000175:diagnosis* / Q000601:surgery; D006801:Humans; D011446:Prospective Studies; D011859:Radiography