Retrospective Study
Copyright ©The Author(s) 2018. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Radiol. Nov 28, 2018; 10(11): 162-171
Published online Nov 28, 2018. doi: 10.4329/wjr.v10.i11.162
New scoring system in assessment of Hoffa’s fat pad synovitis: A comparative study with established scoring systems
Shigeo Hagiwara, Albert Yang, Shoichiro Takao, Yasuhito Kaneko, Taiki Nozaki, Hiroshi Yoshioka
Shigeo Hagiwara, Albert Yang, Shoichiro Takao, Yasuhito Kaneko, Taiki Nozaki, Hiroshi Yoshioka, Department of Radiological Sciences, University of California Irvine Medical Center, Orange, CA 92868, United States
Author contributions: Yoshioka H involved in overseeing the data collection process and data analysis following the data collection; Hagiwara S and Takao S accessed to subject identifiable data and analyzed the data; all the authors have read the manuscript and have approved this submission.
Institutional review board statement: The research protocol of this retrospective study was in compliance with the Helsinki Declaration, was approved by the institutional review board, and was registered with the University of California Irvine Medical Center.
Informed consent statement: The waiver of informed consent was granted by the institutional review board, the University of California Irvine Medical Center.
Conflict-of-interest statement: No conflict of interest to be disclosed.
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: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Hiroshi Yoshioka, MD, PhD, Chief Doctor, Professor, Executive Vice Chair, Department of Radiological Sciences, University of California Irvine Medical Center, 101 The City Drive South, Orange, CA 92868, United States. hiroshi@uci.edu
Telephone: +1-877-8243627
Received: August 4, 2018
Peer-review started: August 5, 2018
First decision: August 24, 2018
Revised: September 22, 2018
Accepted: October 6, 2018
Article in press: October 6, 2018
Published online: November 28, 2018
ARTICLE HIGHLIGHTS
Research background

Osteoarthritis (OA) of the knee is one of the most common chronic disorders resulting in pain, deformity, and loss of function. Several semiquantitative methods using magnetic resonance imaging (MRI) for assessment of knee OA have been developed and used in various observational studies and clinical trials.

Research motivation

Although all assessment methods had been reported to be clinical useful, their reliability was not perfect, and the scoring for Hoffa’s fat pad synovitis based on non-enhanced sequence has not been sufficient, compared with that for the other subregions of the knee.

Research objectives

The aim of this study was to evaluate the reliability of the established and new scoring methods, including non-enhanced MRI, for Hoffa’s fat pad synovitis.

Research methods

This study enrolled 139 knees of 115 patients who underwent MRI of the knee with and without Gadolinium contrast. Proton density (PD)-weighted, proton density-weighted fat-suppressed (PD-FS), and postcontrast T1-weighted fat-suppressed (T1CE) images were used for evaluation. Our grading method for synovitis was performed using non-contrast and contrast images to measure synovial thickness and signal intensity changes of the fat pad (SM score). Intraclass correlation coefficients (ICC) for intra and interobserver reproducibility and the Spearman correlation coefficients (r) with the parapatellar synovitis score were calculated for each scoring method.

Research results

The thickness score in T1CE and the SM scores in T1CE and PD-FS showed substantial to almost perfect reproducibility. The parapatellar synovitis score statistically significant correlation with the thickness score in T1CE (r = 0.68) and thee SM scores in T1CE (r = 0.71) and PD-FS (r = 0.66).

Research conclusions

The newly proposed quantitative thickness score on T1CE and the semiquantitative SM scores on T1CE and PD-FS can be useful for Hoffa’s fat pad synovitis.

Research perspectives

Our findings indicated that the established scoring systems for Hoffa’s fat pad synovitis could be further improved. Future research may propose more reliable methods for Hoffa’s fat pad synovitis.