Acetabular Component Anteversion in Primary and Revision Total Hip Arthroplasty: An Observational Study

Abstract

Purpose: In a prospective manner to evaluate the range of acetabular component anteversion actually achieved by the use of a cup positioner in cementless revision and primary THA.Methods: We operated 71 patients with cementless primary THA, and 26 patients with cementless acetabular revision surgery. We aimed to obtain cup anteversion of 10 to 30° with an impactor-positioner. In all cases we used elevated liners and a ceramic head with diameter 28. At 3 months postoperatively the component versions were measured using CT with the patient in supine position.Results: The acetabular component version in the primary hips ranged from 28° of retroversion to 42° of anteversion with a mean of 17.4 ± 14.0°, while the cup version in the revision hips ranged from 4° of retroversion to 32° of anteversion with a mean of 15.0 ± 9.6°(p=0.427). The anteversion of 40 (56%) of the primary acetabular components were within the target zone of 10 to 30°, while 19 (27%) were below the target zone and and 12 (17%) were above the target range. The anteversion of 19 (73%) of the revision acetabular components were within the target zone, while 6 (23%) were below the target zone and 1 (4%) were above the target range. The differences in distribution between the primary and revision operations were not significant (p=0.183).Conclusions: The intraoperative estimation of acetabular anteversion by free hand technique in many cases was not within the intended range of 10 to 30° in either primary or revision THA and with no differences between the two series

Radiological comparison of acetabular anteversion on roentgenograms and computed tomograms functional outcomes in total hip arthroplasty

“…However, there still exists a dearth of literature regarding the effects of acetabular component positioning on hip functional outcome scores and till date patient satisfaction as a primary outcome in relation to acetabular version has not been done. Reikeras et al [12] concluded that cross-table radiography provides acceptable information for clinical use. Reikeras et al [13] studied that the range of acetabular component anteversion actually achieved by the use of a cup positioner by the freehand technique in many cases was not within the intended range of 10 to 30°.In our study, we used Lewinnek's method [14] which was found to be consistent with CT scans values of measured anteversion angles.…”

Radiological comparison of acetabular anteversion on cross-table lateral roentgenograms and computed tomograms functional outcomes in total hip arthroplasty

“…whereas the mean angle on CT scan was 28.64 0 (Range 11.10-51.10 0 ) with 17(30.90 %) patients were found in Lewinnek safe zone. Reikeras et al [18] concluded that cross-table radiography provides acceptable information for clinical use. Reikeras et al [19] studied that the range of acetabular component anteversion actually achieved by the use of a cup positioner by the freehand technique in many cases was not within the intended range of 10 to 30°.…”

“…The mean anteversion angle was 22.41 0 on cross-table lateral radiographs whereas the mean angle of 28.64 0 was reported on CT scan. Reikeras et al [18] postulated that cross table radiography provides acceptable information for clinical use but has limited use for precise analysis of the acetabular cup version. McArthur et al [23] demonstrated properly positioned, cross-table lateral radiograph-derived measurements are similarly accurate as CT measurements.…”