Artikel
Assessment of pelvic tilt in anteroposterior radiographs by means of tilt ratios
Suche in Medline nach
Autoren
-
Timo Schwarz
- Orthopädische Universitätsklinik Bad Abbach, Bad Abbach, Germany
-
Markus Weber
- Universitätsklinikum Regensburg, Klinik für Orthopädie, Asklepios Klinikum Bad Abbach, Bad Abbach, Germany
-
Achim Benditz
- Regensburg, Germany
-
Hans-Robert Springorum
- Universität Regensburg, Klinik und Poliklinik für Orthopädie, Bad Abbach, Germany
-
Jan Matussek
- Universitätsklinikum Regensburg, Klinik für Orthopädie, Asklepios Klinikum Bad Abbach, Bad Abbach, Germany
-
Guido Heers
- Universitätsklinikum Regensburg, Klinik für Orthopädie, Asklepios Klinikum Bad Abbach, Bad Abbach, Germany
-
Joachim Grifka
- Orthopädische Klinik für die Universität Regensburg, Asklepios Klinikum, Bad Abbach, Germany
-
Benjamin Craiovan
- Orthopädische Universitätsklinik Regensburg, Bad Abbach, Germany
| Veröffentlicht: | 6. November 2018 |
|---|
Gliederung
Text
Objectives: In anteposterior (AP) radiographs, cup position in total hip arthroplasty and acetabular anatomy in hip-preserving surgery are highly influenced by pelvic tilt. The sagittal rotation of the anterior pelvic plane is an important measurement of pelvic tilt during hip surgery. Thus, correct evaluation of cup position and acetabular parameters requires the assessment of pelvic tilt in AP radiographs.
Methods: Changes in pelvic tilt inversely change the height of the lesser pelvis and the obturator foramen in AP radiographs. Tilt ratios were calculated by means of these two parameters in simulated radiographs for 10 male and 10 female pelvises in defined tilt positions. A tilt formula obtained by exponential regression analysis was evaluated by two blinded investigators by means of 14 simulated AP radiographs of the pelvis with pelvic tilts ranging from +15° to -15°.
Results: No differences were found between male and female tilt ratios for each 5° step of simulated pelvic tilt. Pelvic tilt and tilt ratios correlated exponentially. Using the tilt formula, the two blinded investigators were able to assess pelvic tilt with high conformity, a mean relative error of +0.4° (SD +-4.6°), and a mean absolute error of 3.9° (SD +-2.3°). Neutral pelvic tilt is indicated by a tilt ratio of 0.5 when the height of the lesser pelvis is twice the height of the obturator foramen.
Conclusion: The analysis and interpretation of cup position and acetabular parameters may be improved by our method for assessing pelvic tilt in AP radiographs.
