Article
Acetabular retroversion as a contributing factor for posterior traumatic hip dislocation
Search Medline for
Authors
-
S. Steppacher
- Universität Bern, Inselspital, Orthopädische Chirurgie, Bern, Switzerland
-
C. Albers
- Universität Bern, Inselspital, Orthopädie, Bern, Switzerland
-
M. Tannast
- Universität Bern, Inselspital, Orthopädie, Bern, Switzerland
-
K.A. Siebenrock
- Universität Bern, Inselspital, Abteilung für Orthopädische Chirurgie, Bern, Switzerland
-
R. Ganz
- Universität Bern, Klinik für Orthopädische Chirurgie, Gümligen, Switzerland
| Published: | October 18, 2011 |
|---|
Outline
Text
Questionnaire: Traumatic hip dislocation is a rare injury in orthopaedic practice and typically occures in high energy trauma. The goal of this study was to analyze hip morphology in patients with low energy traumatic hip dislocations and to compare it with a control group.
Methods: We performed a retrospective comparative study. The study group included 45 patients with 45 traumatic posterior hip dislocation. The mean age at trauma was 34±15 years (range, 11–68 years) and included 42% of male patients. A low energy trauma was defined as a traumatic hip dislocation without a fracture or with a simple acetabular rim- or head fracture (Pipkin I and II). Traumatic dislocations combined with other acetabular or femoral fractures were excluded. This resulted in 20 dislocations (44%) without a fracture, 14 (31%) with a acetabular rim fracture, 8 (18%) with Pipkin I or II fracture, and 5 (11%) with a combined acetabular rim and femoral head fracture. The control group consisted of 90 patients (180 hips) that underwent radiographic examination for urogenital indication and had no history of hip pain. Hip morphology was assessed on antero-posterior and axial pelvic radiographs including parameters describing acetabular coverage computed by commercially available software called Hip2Norm.
Results and conclusions: The study group showed significantly increased incidence of positive cross-over sign (82% vs. 27%; p<0.001) with a increased retroversion index (26±17 [0–56] vs. 6±12 [0–53]; p<0.001), positive ischial spine sign (70% vs. 34%; p=0<0.001), positive posterior wall sign (79% vs. 21; p<0.001), decreased posterior acetabular coverage (41±10 [17–67] vs. 47±9 [22–71]; p<0.001), and decreased caudocranial coverage (77±12 [42–96] vs. 83±7 [64–100]; p=0.01). Hips that underwent a low energy posterior traumatic hip dislocation show significanly more radiographic sign for acetabular retroversion compared to a control group. Therefore, acetabular retroversion seems to be a contributing factor for posterior traumatic hip dislocation.
