Retrospective Study
Copyright ©The Author(s) 2017. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Orthop. Nov 18, 2017; 8(11): 836-845
Published online Nov 18, 2017. doi: 10.5312/wjo.v8.i11.836
Atlantoaxial rotatory displacement in children
David Spiegel, Shikshya Shrestha, Prakash Sitoula, Norma Rendon, John Dormans
David Spiegel, Division of Orthopaedic Surgery, Children’s Hospital of Philadelphia, Philadelphia, PA 19104, United States
David Spiegel, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, United States
Shikshya Shrestha, Kathmandu Model Hospital, Adwait Marg, Kathmandu 44600, Nepal
Prakash Sitoula, Department of Orthopedics, Nobel Medical College Teaching Hospital, Kanchanbari, Biratnagar 56700, Nepal
Norma Rendon, Center for Fetal Diagnosis and Treatment, Children’s Hospital of Philadelphia, Philadelphia, PA 19104, United States
John Dormans, Department of Orthopaedic Surgery, Texas Children’s Hospital, Houston, TX 77030, United States
Author contributions: Spiegel D and Dormans J came up with the study questions; Spiegel D, Shrestha S, Sitoula P and Rendon N contributed to the study design and IRB application; Spiegel D, Shrestha S, Sitoula P and Rendon N reviewed all of the studies and collected the data; Spiegel D was the primary author of the manuscript; Shrestha S and Sitoula P were secondary authors; Rendon N and Dormans J reviewed the manuscript and provided critical revisions; all authors provided final approval for the article.
Institutional review board statement: The study was reviewed and approved by the Children’s Hospital of Philadelphia’s Institutional Review Board.
Informed consent statement: A waiver of informed consent has been granted by the Children’s Hospital of Philadelphia’s Institutional Review Board to conduct this retrospective study.
Conflict-of-interest statement: The authors declare that they have no conflicts of interest related to this work. Dr. Spiegel has received royalties from Springer for co-editing a textbook.
Data sharing statement: The data is available at request from the corresponding author.
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: David Spiegel, MD, Pediatric Orthopaedic Surgeon, Associate Professor of Orthopaedic Surgery, Division of Orthopaedic Surgery, Children’s Hospital of Philadelphia, 2nd Floor Wood Building, 34th Street and Civic Center Blvd., Philadelphia, PA 19104, United States. spiegeld@email.chop.edu
Telephone: +1-215-5901524 Fax: +1-215-5901501
Received: January 4, 2017
Peer-review started: January 6, 2017
First decision: February 17, 2017
Revised: March 20, 2017
Accepted: April 6, 2017
Article in press: April 10, 2017
Published online: November 18, 2017
Abstract
AIM

To correlate the Pang and Lee class with the clinical course in a consecutive series of patients presenting with painful torticollis.

METHODS

Forty-seven dynamic rotational computed tomography (CT) scans in 35 patients were classified into one of the five types defined by Pang and Li, including types I (atlantoaxial rotatopry fixation), II (“pathologic stickiness” without crossover of C1 on C2), III (“pathologic stickiness” with crossover of C1 on C2), IV (normal or muscular torticollis), and V (diagnostic grey zone). The Pang and Li class was then compared with the radiologist’s report, which was graded abnormal, diagnosis of rotatory subluxation or fixation, or non-diagnostic. Medical records were reviewed and the clinical course was compared among the five sub-types.

RESULTS

We reviewed 47 CT scans in 35 patients, and the majority were performed without sedation. The average age was 7.7 years (4-14 years old) and associated conditions included minor trauma (20%), surgical procedures around the head and neck (29%), and Grisels syndrome (20%). Twenty-six percent of our studies fell within the pathologic spectrum (5% type 1 or rotatory fixation, 21% types 2 and 3 or rotatory subluxation), while 45% were classified as muscular torticollis (45%) and 28% fell within the diagnostic grey zone. Seven radiologists interpreted these studies, and their interpretation was discordant in 45% of cases. Clinical resolution occurred in 27 of 29 cases for which follow-up was available. One of two patients with fixed rotatory subluxation required a C1-C2 arthrodesis.

CONCLUSION

The Pang and Li classification characterizes a spectrum of abnormalities in rotation to facilitate communication, although the indications for dynamic CT scan should be further defined.

Keywords: Atlanto-axial rotatory subluxation, Atlanto-axial rotatory fixation, Dynamic rotational computed tomography, Atlanto-axial rotatory displacement

Core tip: Atlantoaxial rotatory displacement represents a spectrum of pathology. We classified 47 computed tomography (CT) scans in 35 patients presenting with painful torticollis according to Pang and Li, and found that the radiologist’s interpretation was discordant in 45%, suggesting the need to develop a common language with our imaging colleagues to accurately describe this pathology in the individual patient. Most patients resolved with non-operative treatment, although one of two with fixed rotatory subluxation required a fusion. As 74% were classified as muscular torticollis (45%) or fell within the diagnostic grey zone (28%), the indications for a dynamic CT scan should be revisited.