Retrospective Study
Copyright ©The Author(s) 2022. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Orthop. Apr 18, 2022; 13(4): 400-407
Published online Apr 18, 2022. doi: 10.5312/wjo.v13.i4.400
Integrity of the hip capsule measured with magnetic resonance imaging after capsular repair or unrepaired capsulotomy in hip arthroscopy
Niels H Bech, Lode A van Dijk, Sheryl de Waard, Gwendolyn Vuurberg, Inger N Sierevelt, Gino MMJ Kerkhoffs, Daniël Haverkamp
Niels H Bech, Sheryl de Waard, Gino MMJ Kerkhoffs, Department of Orthopedic Surgery, Amsterdam University Medical Center, Amsterdam 1105 AZ, Netherlands
Niels H Bech, Inger N Sierevelt, Daniël Haverkamp, Department of Orthopedic Surgery, Xpert Orthopedic Surgery Clinic, Amsterdam 1101 EA, Netherlands
Niels H Bech, Lode A van Dijk, Department of Orthopedic Surgery, Tergooi Ziekenhuis, Hilversum 1213 XZ, Netherlands
Gwendolyn Vuurberg, Department of Radiology and Nuclear Medicine, Rijnstate Hospital, Arnhem 6815 AD, Netherlands
Gwendolyn Vuurberg, Department of Radiology and Nuclear Medicine, Amsterdam University Medical Center, Amsterdam 1105 AZ, Netherlands
Inger N Sierevelt, Centre for Orthopaedic Research, Spaarne Ziekenhuis, Hoofddorp 2134 TM, Netherlands
Gino MMJ Kerkhoffs, Academic Center for Evidence-Based Sports Medicine, Amsterdam University Medical Center, Amsterdam 1105 AZ, Netherlands
Gino MMJ Kerkhoffs, Amsterdam Collaboration on Health and Safety in Sports, Amsterdam UMC/IOC Research Center, Amsterdam 1105 AZ, Netherlands
Author contributions: Bech NH drafted the manuscript, was involved with data collection, and assisted with data analysis; van Dijk LA drafted the manuscript and participated in design of the study; de Waard S was involved with data collection, and assisted with data analysis; Vuurberg G drafted the manuscript, and assisted with data analysis; Sierevelt IN participated in study design and performed statistical analysis; Kerkhoffs GM participated in study design; Haverkamp D participated in design of the study drafted the manuscript and was involved with data collection; and all authors read and approved the final manuscript.
Institutional review board statement: This study was part of an earlier performed randomized controlled trial. This trial was approved by the local medical ethical committee and was registered at the CCMO Dutch Trial Register: NL55669.048.15.
Informed consent statement: All study participants, or their legal guardian, provided informed written consent prior to study enrollment.
Conflict-of-interest statement: All authors declare that there is no conflict of interest.
Data sharing statement: No additional data are available.
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: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Niels H Bech, MD, Doctor, Department of Orthopedic Surgery, Amsterdam University Medical Center, Meibergdreef 9, Amsterdam 1105 AZ, Netherlands. niels.bech@gmail.com
Received: August 10, 2021
Peer-review started: August 10, 2021
First decision: November 17, 2021
Revised: December 2, 2021
Accepted: March 7, 2022
Article in press: March 7, 2022
Published online: April 18, 2022
Processing time: 244 Days and 17.5 Hours
Abstract
BACKGROUND

Current literature shows no clear answer on the question how to manage the capsule after hip arthroscopy. Regarding patient reported outcome measures there seems to be no difference between capsular repair or unrepaired capsulotomy.

AIM

To evaluate and compare the integrity of the hip capsule measured on a magnetic resonance imaging (MRI) scan after capsular repair or unrepaired capsulotomy.

METHODS

A case series study was performed; a random sample of patients included in a trial comparing capsular repair vs unrepaired capsulotomy had a postoperative MRI scan. The presence of a capsular defect and gap size were independently evaluated on MRI.

RESULTS

A total of 28 patients (29 hips) were included. Patient demographics were comparable between treatment groups. There were 2 capsular defects in the capsular repair group and 7 capsular defects in the unrepaired capsulotomy group (P = 0.13). In the group of patients with a defect, median gap sizes at the acetabular side were 5.9 mm (range: 2.7-9.0) in the repaired and 8.0 mm (range: 4.5-18.0) in the unrepaired group (P = 0.462). At the muscular side gap sizes were 6.6 mm (range: 4.1-9.0) in the repaired group and 11.5 mm (range: 3.0-18.0) in the unrepaired group (P = 0.857). The calculated Odds ratio (OR) for having a capsular defect with an increasing lateral center-edge (CE) angle was 1.12 (P = 0.06). The OR for having a capsular defect is lower in the group of patients that underwent a labral repair with an OR of 0.1 (P = 0.05).

CONCLUSION

There is no significant difference in capsular defects between capsular repair or unrepaired capsulotomy. Regarding clinical characteristics our case series shows that a larger CE angle increases the likelihood of a capsular defect and the presence of a labral repair decreases the likelihood of a capsular defect.

Keywords: Hip; Arthroscopy; Magnetic resonance imaging; Capsule; Thickness

Core Tip: In this case series we evaluated the integrity of the hip capsule after hip arthroscopy with a magnetic resonance imaging scan and compared between patients in a capsular repair group and unrepaired capsulotomy group. The magnetic resonance imaging scan of 29 hips was observed to determine whether there was a capsular defect or not. After 12 mo follow-up no difference was found between groups regarding the presence of a capsular defect or not.