Retrospective Study
Copyright ©The Author(s) 2016. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Orthop. Dec 18, 2016; 7(12): 821-825
Published online Dec 18, 2016. doi: 10.5312/wjo.v7.i12.821
Seasonal variation in adult hip disease secondary to osteoarthritis and developmental dysplasia of the hip
Tatsuya Sueyoshi, Merrill A Ritter, Kenneth E Davis, Randall T Loder
Tatsuya Sueyoshi, Department of Orthopedic Surgery, Kyoto University, Kyoto 606-8507, Japan
Merrill A Ritter, Kenneth E Davis, Center for Hip and Knee Surgery, Mooresville, IN 46158, United States
Randall T Loder, James Whitcomb Riley Children’s Hospital, Indianapolis, IN 46202, United States
Author contributions: Sueyoshi T primary contributed to the work and wrote the manuscript; Ritter MA did the surgery and organized the study; Davis KE did the data collection and statistics; Loder RT made some of developmental dysplasia of the hip comments and gave suggestion.
Institutional review board statement: The study was reviewed and approved by the St. Francis Hospital Institutional Review Board.
Informed consent statement: All study participants or their legal guardian provided consent about personal and medical data collection prior to study enrolment.
Conflict-of-interest statement: All the Authors have no conflict of interest related to the manuscript.
Data sharing statement: The original anonymous dataset is available on request from the corresponding author at
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (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:
Correspondence to: Merrill A Ritter, MD, Center for Hip and Knee Surgery, 1199 Hadley Road, Mooresville, IN 46158, United States.
Telephone: +1-317-8345263
Received: January 12, 2016
Peer-review started: January 14, 2016
First decision: March 7, 2016
Revised: August 8, 2016
Accepted: August 17, 2016
Article in press: August 18, 2016
Published online: December 18, 2016
Core Tip

Core tip: The purpose of this study was to determine if there was a seasonal variation undergoing total hip arthroplasty for osteoarthritis (OA) or developmental dysplasia of the hip (DDH). Differences between number of births observed and expected in the winter months and non-winter months were analyzed with the χ2 test. There were 7792 OA and 60 DDH, and more births than expected in the winter months for both the DDH (P < 0.0001) and the OA (P = 0.0052) cohorts. These data clearly demonstrated an increased prevalence of DDH and OA in those patients born during the winter months.