Utility of CT-based navigation in revision total hip arthroplasty for a patient with severe posterior pelvic tilt-case report-

Abstract

Background: Hip dislocation after total hip arthroplasty (THA) or hemi-arthroplasty is a rare but serious complication. Dislocation may be prevented by appropriate positioning of the cup angle of inclination and anteversion. Case presentation: This report describes a 66-year-old woman who underwent revision THA using a computer tomography (CT)-based navigation system to treat an anterior dislocation after hemi-arthroplasty due to a severe posterior pelvic tilt. At initial presentation, her sagittal pelvic tilt angle, measured as anterior pelvic plane (APP) in the supine position, was 38 degrees posterior to the coronal plane. Owing to the posterior pelvic tilt, revision THA was performed using CT-based navigation, while dual mobility was utilized to reduce the risk of re-dislocation. Postoperatively, her sagittal pelvic tilt angle showed further progression over time, with an APP of 66 degrees posterior to the coronal plane in the standing position 3 years after revision THA. Simulation with the Zed Hip system showed that the risk of implant-to-implant impingement was much higher posteriorly than anteriorly. Gait analysis demonstrated hyperextension of the hip joint while walking, although hip joint function required for daily activity was maintained. Conclusions: Preoperative planning of implant orientation, based on posterior progression of pelvic tilt and accurate placement of components, is important to prevent dislocation in patients with severe posterior pelvic tilt. A dual mobility cup may also improve hip function in these patients.

What Changes in Pelvic Sagittal Tilt Occur 20 Years After THA?

“…In this study, the proportion of patients with posterior D standing increased during the follow-up period, and 34% of patients had a D standing greater than 15°posteriorly at 20 years. Some previous reports have determined individual variations between preoperative supine PT and postoperative standing or sitting PT to determine additive postoperative changes in PT and PT shift over time [14,37]. An earlier study reported a mean D standing of -9.5°at 1 year postoperatively in patients with a mean age of 66 years [14], and another study reported one patient with D standing of -28°at 3 years postoperatively [37].…”

“…Pelvic sagittal tilt (PT) differs in various positions, including the supine, standing, and sitting positions [16,23]. PT affects the cup's orientation after THA, and patterns of PT shift (such as excessive posterior PT shift from the supine to standing position) may increase the risk of postoperative dislocation and edge loading [15,18,28,37]. Recently, decreased posterior shift in PT from the standing to sitting positions has been reported as possibly contributing to postoperative dislocation [8,13].…”

Using Gait Analysis to Evaluate Hip Replacement Outcomes—Its Current Use, and Proposed Future Importance: A Narrative Review

“…Search strategy terms were (gait analysis OR gait) AND (total hip replacement OR total hip arthroplasty OR hip replacement surgery OR THR) AND (robotic surgery OR navigation OR PSI). Only three articles [ 16 , 17 , 18 ] were found to evaluate the effect of new THR surgical technologies on gait.…”

“…Reininga et al [ 17 ], findings suggested that although gait improved after surgery, small differences in several spatiotemporal parameters and angular movements of the trunk remained at 6 months postoperatively between both patient groups and healthy subjects. The third study was a case report by Watanabe et al [ 18 ], describing a revision THR surgery of a 66-year-old woman using a computer tomography-based navigation system. This study aimed to use the navigation system to optimise the cup placement in the presence of a severe posterior pelvic tilt.…”

“…This study collected only five gait cycles and did not outline their justification for this number. Bach et al [ 16 ] and Reininga et al [ 17 ] both provided gait data at six months post-THR surgery, whereas the case report by Watanabe et al [ 18 ] provided gait data at three years postsurgery time-point. An important limitation of all studies was their lack of kinetic gait data reports.…”