Retrospective Cohort Study
Copyright ©The Author(s) 2021. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Orthop. Jun 18, 2021; 12(6): 395-402
Published online Jun 18, 2021. doi: 10.5312/wjo.v12.i6.395
Dermatomyositis and polymyositis in total hip arthroplasty
Samuel Rosas, Michael Schallmo, Anirudh Krishna Gowd, Matthew Reynolds Akelman, T David Luo, Cynthia Lynn Emory, Johannes Frank Plate
Samuel Rosas, Anirudh Krishna Gowd, Matthew Reynolds Akelman, T David Luo, Cynthia Lynn Emory, Johannes Frank Plate, Department of Orthopedic Surgery, Wake Forest School of Medicine, Winston Salem, NC 27101, United States
Michael Schallmo, Department of Orthopedic Surgery, Atrium Healthcare, Charlotte, NC 28203, United States
Author contributions: All of the authors have contributed to the final manuscript encompassed herein.
Institutional review board statement: Retrospective, HIPAA compliant database does not require IRB review.
Informed consent statement: The written informed consent was waived.
Conflict-of-interest statement: None of the authors report a conflict of interest with this paper.
Data sharing statement: Technical appendix, statistical code, and dataset available from the corresponding author at
STROBE statement: The authors have read the STROBE Statement—checklist of items, and the manuscript was prepared and revised according to the STROBE Statement—checklist of items.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Corresponding author: Samuel Rosas, MD, PhD, Doctor, Department of Orthopedic Surgery, Wake Forest School of Medicine, 1 Medical Center Boulevard, Winston Salem, NC 27101, United States.
Received: January 3, 2021
Peer-review started: January 3, 2021
First decision: March 1, 2021
Revised: March 22, 2021
Accepted: May 20, 2021
Article in press: May 20, 2021
Published online: June 18, 2021

Idiopathic inflammatory myopathies (IIM) are systemic autoimmune disorders such as dermatomyositis (DM), polymyositis (PM), inclusion body myopathy, and autoimmune necrotizing myopathy that, similar to osteoarthritis, affect quality of life and activities of daily living. Moreover, these patients are often burdened with chronic pain and disability; however, the outcomes and risk of total hip arthroplasty (THA) in this patient population remain unclear.


To evaluate 90-d complications and costs in patients with these conditions.


A retrospective case control study was designed by accessing data from the Medicare dataset available on the PearlDiver server. Patients with IIM, here, those with DM and PM were matched based on possible confounding variables to a cohort without these diseases and with the same 10-year risk of mortality as defined by the Charlson Comorbidity Index Score (CCI). Univariate and multivariate analysis were performed to evaluate complications and t-tests to evaluate 90-d Medicare reimbursements as markers of costs after THA.


The total sample was 1090 patients with each cohort comprised of 545. Females were 74.9% of the population. The mean CCI was 5.89 (SD 2.11). Those with IIM had increased rates of pneumonia [odds ratio (OR) 1.45, P < 0.001] and pulmonary embolism (OR 1.46, P = 0.035) and decreased hematoma risks (OR 0.58, P = 0.00). 90-d costs were on average $1411 greater for those with IIM yet not significantly different (P = 0.034).


Patients with IIM have an increased 90-d rate of pneumonia and pulmonary embolism concomitant with a decreased hematoma rate consistent with their pro-coagulatory state. Further attention to increased resource utilization in these patients is also warranted.

Keywords: Dermatomyositis, Arthroplasty, Polymyositis, Outcomes, Charges, Reimbursement

Core Tip: Patients with dermatomyositis have an increased 90-d rates of pneumonia and pulmonary embolisms. The increased rates of these complications is concordant with a decreased hematoma rates consistent with the prothrombotic state of these patients. Surgeons should remember the implications of dermatomyositis when patients are undergoing total hip arthroplasty, and further discuss deep vein thrombosis prophylaxis.