Open Access
CC BY-NC-ND 4.0 · J Knee Surg 2023; 36(08): 806-813
DOI: 10.1055/s-0042-1743494
Original Article

Higher Pelvic Incidence Was Associated with a Higher Risk of Sagittal Malposition of Femoral Component and Poor Outcomes of Primary Total Knee Arthroplasty: A Retrospective Cohort Analysis

Autor*innen

  • Hongyi Li*

    1   Department of Orthopaedics, Qingyuan People' Hospital/the Sixth Affiliated Hospital of Guangzhou Medical University, Qingyuan, China
    2   Department of Joint Surgery, the First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
    3   Guangdong Provincial Key Laboratory of Orthopedics and Traumatology, Guangzhou, China
  • Fei Zhu*

    2   Department of Joint Surgery, the First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
  • Shufen Liao

    4   Department of Surgery, the First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
  • Xiangjiang Wang

    1   Department of Orthopaedics, Qingyuan People' Hospital/the Sixth Affiliated Hospital of Guangzhou Medical University, Qingyuan, China
  • Yanlin Zhong

    2   Department of Joint Surgery, the First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
  • Xingzhao Wen

    2   Department of Joint Surgery, the First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
  • Xiaoyi Zhao

    2   Department of Joint Surgery, the First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
  • Weiming Liao

    2   Department of Joint Surgery, the First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
  • Zhiqi Zhang

    2   Department of Joint Surgery, the First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China

Funding This work was supported by fundings received by Z.Z. (grant number: 81972049, 19ykpy63), fundings received by W.L. (grant numbers: 81874016, 81672145), and grants received by X.Z. (grant numbers: 2016A030310156, 2019A030317007).

Abstract

Spine–pelvis–lower extremity sagittal alignment is regarded as a global sagittal balance. Currently, there are few studies evaluating the pelvic and femoral sagittal alignment during total knee arthroplasty (TKA). This retrospective study aims to elucidate how pelvic and femoral sagittal alignment affect clinical outcomes of primary TKA for osteoarthritis (OA) and determine the proper range of femoral sagittal alignment. Patient-reported outcome measures (PROMs), including the Knee Society Score (KSS), Western Ontario and McMaster Universities (WOMAC), and patient satisfaction scores, and clinician-reported outcomes (CROs), including range of motion (ROM) and pelvic and femoral sagittal parameters, of 67 cases were evaluated (89 knees) before and 1 year after TKA. The angle between the distal femur anterior cortex line and flange of the femoral component (FC) was defined as the α angle. Correlations between the α angle and PROM and CRO were investigated using multivariate and secondary regression analyses. Patients were further divided into four cohorts (A, B, C, and D) according to the α angle, and comparisons of their postoperative PROM and ROM scores were performed. Postoperative PROM and ROM scores improved significantly compared with the preoperative scores (p < 0.01). Only the α angle was significantly associated with postoperative knee extension among all PROM and CRO indexes (p = 0.001). Secondary regression demonstrated a convex upward function, and the scores were the highest at α angles of 0.57, 0.96, and −1.42 degrees for postoperative KSS, satisfaction, and range of knee extension, respectively (p< 0.01). However, the concave upward degree was the lowest at an α angle of 0.33 degrees for pelvic incidence (p < 0.001). Bonferroni's paired comparisons indicated that postoperative KSS and satisfaction of the cohort B (0 degrees ≤ α angle ≤ 3 degrees) were better than those of other cohorts (p < 0.0125). The results indicate that surgeons should pay more attention to the sagittal alignment of FC in patients with increased pelvic incidence, the distal femoral anterior cortex is recommended as an anatomic landmark, and 0 to 3 degrees might be “safe zones” of the sagittal flexion of FC in TKA. This study reflects the level of evidence III.

Ethical Approval

This retrospective study was approved by the First Affiliated Hospital of Sun Yat-sen University Clinical Research Ethics Committee (Guangzhou, China, Institutional Review Board [IRB] no. 2013–032).


Authors' Contributions

H.L. conceived, designed, performed research, and prepared manuscript. F.Z. conceived, designed, and performed clinical follow-up. S.L. collected clinical data and performed clinical follow-up. X.W. collected clinical data and performed clinical follow-up. Y.Z. collected clinical data and performed clinical follow-up. X.W. contributed with analysis and interpretation of the data and prepared table and figures. X.Z. collected clinical data and performed clinical follow-up. W.L. supervised the study and revised manuscript. Z.Z. conceived, designed, supervised the study, and revised manuscript. H.L. and F.Z. are regarded as co–first authors. Z.Z. is regarded as the corresponding author.


* These authors are regarded as co–first authors.




Publikationsverlauf

Eingereicht: 31. August 2020

Angenommen: 09. Januar 2022

Artikel online veröffentlicht:
11. April 2022

© 2022. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commercial purposes, or adapted, remixed, transformed or built upon. (https://creativecommons.org/licenses/by-nc-nd/4.0/)

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