Postoperative excessive external femoral rotation in revision total hip arthroplasty is associated with muscle weakness in iliopsoas and gluteus medius and risk for hip dislocation

Hyonmin Choe; Naomi Kobayashi; Daigo Kobayashi; Shintaro Watanabe; Koki Abe; Taro Tezuka; Yusuke Kawabata; Masanobu Takeyama; Yutaka Inaba

doi:10.1186/s13018-021-02744-4

Postoperative excessive external femoral rotation in revision total hip arthroplasty is associated with muscle weakness in iliopsoas and gluteus medius and risk for hip dislocation

J Orthop Surg Res. 2021 Oct 9;16(1):582. doi: 10.1186/s13018-021-02744-4.

Authors

Hyonmin Choe¹, Naomi Kobayashi², Daigo Kobayashi³, Shintaro Watanabe³, Koki Abe³, Taro Tezuka³, Yusuke Kawabata³, Masanobu Takeyama³, Yutaka Inaba³

Affiliations

¹ Department of Orthopaedic Surgery, Yokohama City University, 3-9 Fukuura, Kanazawa-ku, Yokohama City, Kanagawa, 236-0004, Japan. hyonmin@hotmail.com.
² Department of Orthopaedic Surgery, Yokohama City University Medical Center, 4-57 Urahune-cho, Minami-ku, Yokohama City, Kanagawa, 232-0024, Japan.
³ Department of Orthopaedic Surgery, Yokohama City University, 3-9 Fukuura, Kanazawa-ku, Yokohama City, Kanagawa, 236-0004, Japan.

Abstract

Background: Excessive external femoral rotation (FR) can functionally increase stem anteversion (SA) and is often observed at an early stage after surgery in revision total hip arthroplasty (THA). This study was conducted to investigate the prevalence of external FR, identify the factors associated with external FR, and determine the association of FR and other factors with hip dislocation in revision THA.

Methods: We enrolled 51 revision THA patients (55 hip cases). The patient background, angle of anatomical and functional SA, FR angle, sizes and densities of muscles around the hip joint, impingement distance, and consequence of postoperative hip dislocation were assessed by reviewing their medical history and imaging data that includes computed tomography (CT) scans before and after surgery.

Results: Forty-five hip cases (81.8%) showed external FR (mean 13.0°). External FR was significantly correlated with anatomical SA (r = - 0.54) and increase in functional SA (r = 0.36), which was significantly correlated with impingement distance (r = 0.46). The independent factors associated with external FR in multivariate analysis were the anatomical SA, CT densities of the psoas, gluteus medius and maximus muscles, and 2-stage revision (R² = 0.559). During follow-up period, eight cases of revision THA showed hip dislocation. FR, functional SA, impingement distance, CT density of psoas and gluteus medius muscle, body mass index, number of past operation, and ratio of 2-stage revision THA were significantly different between cases with dislocation and non-dislocation. The odds ratio of FR and impingement distance for hip dislocation was identified as 1.061(95% confidence interval (CI): 1.011-1.114) and 0.901 (95% CI 0.820-0.991), respectively.

Conclusions: Revision THA frequently causes an external FR that functionally increases the SA and impingement risk, particularly in hips with 2-stage revision with psoas and gluteus medius muscle atrophy. Patients who have undergone revision THA and have an excessive external FR may require careful monitoring for possible hip dislocation due to hip joint instability and impingement.

Keywords: Dislocation; Femoral rotation; Functional stem anteversion; Impingement; Muscle atrophy; Revision total hip arthroplasty.

MeSH terms

Arthroplasty, Replacement, Hip* / adverse effects
Hip Dislocation* / diagnostic imaging
Hip Dislocation* / epidemiology
Hip Dislocation* / surgery
Hip Joint / diagnostic imaging
Hip Joint / surgery
Hip Prosthesis*
Humans
Muscle Weakness
Reoperation
Retrospective Studies