The Influence Of Spinal Morphology On The Standing-To-Supine Pelvis Mobility In Preoperative Planning For…

Cohort studyOrthopaedics & traumatology, surgery & research : OTSR· Aug 2026

The Influence Of Spinal Morphology On The Standing-To-Supine Pelvis Mobility In Preoperative Planning For Total Hip Arthroplasty. Consequences in THA planning.

Danilo Casasola, Amira Peirson, Sena Boukhelifa, Elhadi Sariali

ArthroplastyCohort studyClinical practiceQ1IF 3.0

56% of patients had increased sacral slope moving from standing to supine before hip surgery

The Influence Of Spinal Morphology On The Standing-To-Supine Pelvis Mobility In Preoperative Planning For Total Hip Arthroplasty. Consequences in THA planning.

Danilo Casasola … Elhadi Sariali

Orthopaedics & traumatology, surgery & research · Aug 2026 · Q1 in Orthopedics

Background

Many authors have highlighted the importance of assessing spinal alignment and mobility during total hip arthroplasty (total hip arthroplasty), particularly regarding acetabular positioning.

Purpose

The study aims to analyse this relationship in preoperative patients and its implications for planning acetabular anteversion.

Methods

This retrospective study included 93 patients who underwent total hip arthroplasty between January 2021 and December 2022, using 3D CT-based planning and a preoperative EOS image in the standing position.

n = 93 patients

Results

sacral slope rose from standing to supine in most patients, shifting cup positioning

Standing

41°

Supine

46°

More results

41 ° (SD 8 °); p < 0.001).

The mean difference in sacral slope (sacral slope) between these two positions was 4.2 ° (-12 ° to 17 °, SD 6.1 °).

More results

An anterior pelvic tilt when moving to the supine position was observed in patients with Roussouly type 1 and type 3 spinal morphologies (p < 0.01), whereas patients with Roussouly type 3A and type 4 morphologies showed no significant change in sacral slope between the standing and supine positions.

“

Conclusion · 1 of 3

Contrarily to the other groups who experienced an anterior pelvis tilt when moving from standing to supine, in patients with Roussouly types 3A and 4, the pelvis orientation and consequently the acetabular anteversion remained unchanged.

Conclusion · 2 of 3

A paradoxical posterior pelvic tilt was observed in 9% of patients (mainly DDH), resulting in increased functional acetabular anteversion and a potentially higher risk of anterior dislocation.

Conclusion · 3 of 3

In these patients, a reduction in cup anteversion may be considered during total hip arthroplasty.

The Influence Of Spinal Morphology On The Standing-To-Supine Pelvis Mobility In Preoperative Planning For Total Hip Arthroplasty. Consequences in THA planning.

The Influence Of Spinal Morphology On The Standing-To-Supine Pelvis Mobility In Preoperative Planning For Total Hip Arthroplasty. Consequences in THA planning.

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