Proposal of a new indicator of hip compensation for spinopelvic–hip mismatch - a retrospective study in Japan

Q: What was the purpose of the study?

To develop an indicator of hip compensatory capacity in response to spinopelvic mismatch using standard radiographs.

Q: How were patients grouped in the analysis?

Patients were divided into PI–LL <20° and PI–LL ≥20° groups, based on pelvic incidence–lumbar lordosis.

Q: Which parameter showed the strongest association with SVA?

PFA–(PI–LL) demonstrated the strongest association with the sagittal vertical axis (SVA) and explained variations in sagittal alignment in both groups.

Sep 29, 2026

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A retrospective clinical study developed a radiographic indicator to quantify hip joint compensatory capacity in response to spinopelvic–hip mismatch using standard radiographs. The analysis included 209 osteoporosis patients and 54 adult spinal deformity patients, grouped by PI–LL (<20° vs ≥20°). Key sagittal parameters and HRQOL (JOABPEQ) were correlated with radiographic measures, focusing on their relationship with SVA. The new index, PFA–(PI–LL), showed the strongest association with SVA and was linked to anterior trunk inclination and HRQOL across domains.

LanguageEnglish

CategoryHealthcare

FormatPDF

Pages11

Reading Time28 min

AccessFree to download

Study design

Purpose

Methods

Results

Conclusions

Introduction

Background and rationale

Spinopelvic parameters and hip–spine syndrome

Clinical Study ASJ Asian Spine J. 2025;19(6): 967-977 [https://doi.org/10.31616/asj.2024.0475](https://doi.org/10.31616/asj.2024.0475)[ ](https://doi.org/10.31616/asj.2024.0475)PISSN 1976-1902 • eISSN 1976-7846 Proposal of a new indicator of hip compensation for spinopelvic–hip mismatch: a retrospective study in Japan Ryo Fujita, Kohei Takahashi, Ko Hashimoto, Kazuyoshi Baba, Kenichiro Yahata, Takahiro Onoki, Takashi Aki, Keisuke Ishikawa, Toshimi Aizawa Department of Orthopaedic Surgery, Tohoku University Graduate School of Medicine, Sendai, Japan Proposal of a new indicator of hip compensation for spinopelvic–hip mismatch: a retrospective study in Japan Results 4003002001000 –100 – 20 0 20 40 60 80 100 PI–LL (°) 4003002001000 –100 100 120 140 160 180 200 220 PFA–(PI–LL) (°) Among all parameters, PFA–(PI–LL) demonstrated the strongest association with SVA. Scatter diagrams between SVA and PI–LL Scatter diagrams between SVA and PFA–(PI–LL) PI – – LL ≥20 LL <20 ° PI ° group – group – LL was LL not correlated correlated with PFA with PFA SVA (mm) SVA (mm) Significant correlations were observed between the radiographic parameters and JOABPEQ scores across all domains. CONCLUSION PFA–(PI–LL), which represented spinopelvic–hip mismatch, was a reliable indicator of hip compensatory function in terms of anterior trunk inclination and HRQOL. Ryo Fujita et al. Asian Spine J. 2025;19(6): 967-977. [doi.org/10.31616/asj.2024.0475](doi.org/10.31616/asj.2024.0475) Received Nov 19, 2024; Revised Apr 13, 2025; Accepted Apr 17, 2025 Corresponding author: Ryo Fujita Department of Orthopaedic Surgery, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan Tel: +81-22-717-7245, Fax: +81-22-717-7248, E-mail: [ryo.fujita.e7@tohoku.ac.jp](ryo.fujita.e7@tohoku.ac.jp) Copyright Ⓒ 2025 by Korean Society of Spine Surgery This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License ([http://creativecommons.org/licenses/by-nc/4.0/](http://creativecommons.org/licenses/by-nc/4.0/)) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Asian Spine Journal • pISSN 1976-1902 eISSN 1976-7846 • [www.asianspinejournal.org](www.asianspinejournal.org) Proposal of a new indicator of hip compensation for spinopelvic–hip mismatch: a retrospective study in Japan Ryo Fujita, Kohei Takahashi, Ko Hashimoto, Kazuyoshi Baba, Kenichiro Yahata, Takahiro Onoki, Takashi Aki, Keisuke Ishikawa, Toshimi Aizawa Study Design: retrospective study. Purpose: This study aimed to develop an indicator of the compensatory capacity of hip joints in response to spinopelvic mismatch using standard radiographs. Overview of Literature: EOS imaging has enabled detailed analysis of hip and lower extremity compensation in sagittal malalignment. However, its high cost and limited availability hinder widespread clinical use. Currently, there are no established indicators to assess hip compensation for spinopelvic mismatch using standard radiographs. Methods: A total of 209 patients with osteoporosis and 54 with adult spinal deformities were included. Patients were divided into two groups based on pelvic incidence–lumbar lordosis (PI–LL): <20° and ≥20° groups. The sagittal vertical axis (SVA), thoracic kyphosis, PI, pelvic tilt (PT), LL, sacral slope, and pelvic femoral angle (PFA) were measured. Health-related quality of life (HRQOL) was assessed in 86 patients using the Japanese Orthopedic Association Back Pain Evaluation Questionnaire (JOABPEQ) . A new index, PFA–(PI–LL), was defined as spinopelvic–hip mismatch. Correlation coefficients were calculated for each radiographic parameter, and the coefficient of determination (R2) for the relationship of each parameter with SVA was evaluated in both groups. The corr

FAQs

What was the purpose of the study?

To develop an indicator of hip compensatory capacity in response to spinopelvic mismatch using standard radiographs.

How were patients grouped in the analysis?

Patients were divided into PI–LL <20° and PI–LL ≥20° groups, based on pelvic incidence–lumbar lordosis.

Which parameter showed the strongest association with SVA?

PFA–(PI–LL) demonstrated the strongest association with the sagittal vertical axis (SVA) and explained variations in sagittal alignment in both groups.

Sep 29, 2026

Uploaded by Ophelia