Changes in spinopelvic indices after hip arthroplasty and its influence on acetabular component orientation

Siddharth Mahesh Shah; Selin Munir; William Lindsay Walter

doi:10.1016/j.jor.2017.07.018

Changes in spinopelvic indices after hip arthroplasty and its influence on acetabular component orientation

J Orthop. 2017 Aug 1;14(4):434-437. doi: 10.1016/j.jor.2017.07.018. eCollection 2017 Dec.

Authors

Siddharth Mahesh Shah¹, Selin Munir¹, William Lindsay Walter¹

Affiliation

¹ Specialist Orthopaedic Group, Mater Misericordiae Hospital, 25 Rocklands Road, North Sydney, NSW 2060, Australia.

Abstract

Objective: To evaluate spinopelvic changes after hip arthroplasty in standing and ready-to-rise positions.

Methods: We compared pelvic tilt, sacral slope, cobb's angle, and hip flexion on pre and postoperative spinopelvic radiographs.

Results: Standing: All postoperative indices were similar to preoperative ones except sacral slope (mean difference:1.6°, p = 0.046). Ready-to-rise: All postoperative indices were similar to preoperative ones except pelvic tilt which was significantly greater postoperatively (mean difference: 5.1°, p = 0.017). Fifteen patients showed >10° increase in pelvic tilt postoperatively.

Conclusion: Changes in pelvic tilt in ready-to-rise position can predispose to posterior edge loading, edge wear, and dislocation; especially with inadequate cup anteversion.

Keywords: APP, anterior pelvic plane; ASIS, anterior superior iliac spine; DAA, direct anterior approach; Edge loading; FPP, functional pelvic plane; OA, osteoarthritis; Pelvic tilt; ROM, range of motion; SD, standard deviation; Spinopelvic; THA, total hip arthroplasty; Total hip arthroplasty.