Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2020 Mar;44(3):429-435.
doi: 10.1007/s00264-020-04484-2. Epub 2020 Jan 22.

Acetabular positioning is more consistent with the use of a novel miniature computer-assisted device

Ivan Jacob  1 , Jessica Benson  2 , Kate Shanaghan  1 , Alejandro Gonzalez Della Valle  3
Affiliations

Acetabular positioning is more consistent with the use of a novel miniature computer-assisted device

Ivan Jacob et al. Int Orthop. 2020 Mar.

Abstract

Introduction: Computer-assisted surgery (CAS) relying on registration of the anterior pelvic plane (APP) allows precise acetabular component placement. We determined the variability of cup placement in patients who underwent THA with and without the use of CAS that does not rely on the registration of APP.

Methods: Fifty-one patients who underwent staged-bilateral THAs, one without CAS (control), and a subsequent one with CAS (study group), were included. Acetabular inclination and anteversion were measured on standardized post-operative radiographs. Variance in cup position and Lewinnek's zone proportionality were compared between the groups. Multiple regressions were performed to identify factors affecting variability in acetabular component placement.

Results: The mean inclination for the control and study group was 42.7° (SD 4.5) and 42.5° (SD 2.9), respectively. The inclination variance was 20.5° and 8.2° respectively (p = < 0.001). Cup inclination was more consistent in the study than in the control group (deviation from the mean: 2.3° vs. 3.8°, p < 0.001). The mean anteversion for the control and the study group was 25.5° (SD 7.4) and 26.8° (SD 4.3), respectively. The anteversion variance was 54.2° and 18.2° respectively (p = <0.001). Consistency in cup anteversion was significantly improved with CAS (deviation from the mean: 3.4° vs. 5.8°; p = 0.002). Lewinnek's zone proportionality was not affected by the use of CAS. In the linear regression analysis, CAS significantly increased consistency in cup inclination (p = 0.01). Patient's factors including BMI and laterality affected consistency of cup placement.

Conclusion: CAS without referencing the APP allows a more consistent orientation of the acetabular component when compared to freehand placement.

Keywords: Anterior pelvic plane; Computer-assisted surgery; Cup position; Total hip arthroplasty.

PubMed Disclaimer

References

    1. Gonzalez Della Valle A, Padgett DE, Salvati EA (2005) Preoperative planning for primary total hip arthroplasty. J Am Acad Orthop Surg 13(7):455–462 - DOI
    1. Murphy WS, Yun HH, Hayden B, Kowal JH, Murphy SB (2018) The safe zone range for cup anteversion is narrower than for inclination in THA. Clin Orthop Relat Res 476(2):325–335 - DOI
    1. Kennedy JG, Rogers WB, Soffe KE, Sullivan RJ, Griffen DG, Sheehan LJ (1998) Effect of acetabular component orientation on recurrent dislocation, pelvic osteolysis, polyethylene wear, and component migration. J Arthroplast 13(5):530–534 - DOI
    1. Hassani H, Cherix S, Ek ET, Rüdiger HA (2014) Comparisons of preoperative three-dimensional planning and surgical reconstruction in primary cementless total hip arthroplasty. J Arthroplast 29(6):1273–1277 - DOI
    1. Lee YK, Biau DJ, Yoon BH, Kim TY, Ha YC, Koo KH (2014) Learning curve of acetabular cup positioning in total hip arthroplasty using a cumulative summation test for learning curve (LC-CUSUM). J Arthroplast 29(3):586–589 - DOI

Publication types

LinkOut - more resources