Case Control Study
Copyright ©The Author(s) 2022. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Orthop. Sep 18, 2022; 13(9): 791-801
Published online Sep 18, 2022. doi: 10.5312/wjo.v13.i9.791
Histological difference in ligament flavum between degenerative lumbar canal stenosis and non-stenotic group: A prospective, comparative study
Mantu Jain, Mukund Sable, Amit Purushottam Tirpude, Rabi Narayan Sahu, Sudeep Kumar Samanta, Gurudip Das
Mantu Jain, Sudeep Kumar Samanta, Gurudip Das, Department of Orthopaedics, All India Institute of Medical Sciences Bhubaneswar, Bhuabneswar 751019, Odisha, India
Mukund Sable, Department of Pathology, All India Institute of Medical Sciences Bhubaneswar, Bhubaneswar 751019, Odisha, India
Amit Purushottam Tirpude, Department of Anatomy, All India Institute of Medical Sciences Raipur, Raipur 492009, Chattisgarh, India
Rabi Narayan Sahu, Department of Neurosurgery, All India Institute of Medical Sciences Bhubaneswar, Bhubaneswar 751019, Odisha, India
Author contributions: Jain M, Sable B, Tirpude AP, and Sahu RN conceived the idea; Jain M got the ethical clearance and grant for the study; Jain M, Sahu RN, and Das G collected the sample; Sable M and Tirpude AP performed the histological analysis; The data were compiled by Jain M and Samanta SK; Sable M and Jain M performed the statistical analysis; Jain M, Samanta SK, and Das G wrote the manuscript, whereas the other authors provided critical inputs; All authors have read and agree to the content of the manuscript.
Supported by Institutional research grant (AIIMS Bhubaneswar).
Institutional review board statement: The study was reviewed and approved by the Institutional ethics committee of AIIMS Bhubaneswar (T/IM/18-19/43 dated 04/01/2019).
Informed consent statement: All patients gave informed consent.
Conflict-of-interest statement: There is no conflict of interest.
Data sharing statement: Participants gave informed consent for data sharing.
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: Mantu Jain, MD, Doctor, Surgeon, Department of Orthopaedics, All India Institute of Medical Sciences Bhubaneswar, Bhuabneswar 751019, Odisha, India. montu_jn@yahoo.com
Received: January 17, 2022
Peer-review started: January 17, 2022
First decision: February 21, 2022
Revised: March 2, 2022
Accepted: August 24, 2022
Article in press: August 24, 2022
Published online: September 18, 2022
Processing time: 241 Days and 17.8 Hours
Abstract
BACKGROUND

Ligament flavum (LF) hypertropy is the main etiopathogenesis of lumbar canal stenosis (LCS). The purely elastic LF undergoes a morphological adaptation including a reduction in the elastic fibers and a consequent increase in the collagen content, fibrosis, cicatrization, and calcification. However, the morphometric analysis can delineate the LF in patients with LCS from those without LCS, which would help in better understanding LCS pathogenesis.

AIM

To compare the histopathological changes in LF between the degenerative LCS and non-stenotic (non-LCS) group.

METHODS

The present prospective study was conducted in 82 patients who were divided into two groups, namely LCS and non-LCS. Demographic details of the patients such as duration of symptoms, level of involvement, and number of segments were recorded. The LF obtained from both groups was histopathologically examined for the fibrosis score, elastic fiber degeneration, calcification, and chondroid metaplasia. Morphometrical details included a change in elastin and collagen percentages, elastin/collagen ratio, elastic fiber fragmentation, and ligamentocyte numbers. All parameters were compared between the two groups by using the independent t test, Chi-square test, and Pearson’s correlation test.

RESULTS

Out of 82 cases, 74 were analysed, 34 in LCS and 40 in non-LCS group. The mean ± SD age of presentation in LCS and non- LCS group was 49.2 ± 8.9 and 43.1 ± 14.3 respectively. The LCS group (n = 34) exhibited significant differences in fibrosis (P = 0.002), elastic fiber degeneration (P = 0.01), % elastic fragmentation (66.5 ± 16.3 vs 29.5 ± 16.9), % elastic, content (26.9 ± 6.7 vs 34.7 ± 8.4), % collagen content (63.6 ± 10.4 vs 54.9 ± 6.4), reduction of elastic/collagen (0.4 ± 0.1 vs 0.6 ± 0.1), and ligamentocyte number (39.1 ± 19.1 vs 53.5 ± 26.9) as compared to non-LCS group (n = 40). The calcification (P = 0.08) and Pearson’s correlation between duration and loss of elastin was not significant. The difference in LF morphology is consistent in patient’s ≥ 40 years of age among the groups as found in subgroup analysis. Similarly in the patents < 40 and > 40 in the non-LCS group.

CONCLUSION

LF is vital in the pathogenesis of LCS. The purely elastic LF undergoes a morphological adaptation that includes a reduction in the elastic fibers with a consequent increase in the collagen content, fibrosis, cicatrization, and calcification. The present study provides a detailed morphometric analysis to semiquantitatively delineate the LF changes in patients with LCS from those in patients without LCS.

Keywords: Spinal stenosis; Lumbar spine; Ligamentum flavum; histopathology; Morphometry

Core Tip: The ligament flavum (LF) is vital in the pathogenesis of lumbar canal stenosis (LCS). The purely elastic LF undergoes a morphological adaptation that includes a reduction in the elastic fibers with a consequent increase in the collagen content, fibrosis, cicatrization, and calcification. The present study provides a detailed morphometric analysis to semiquantitatively delineate the LF changes in patients with LCS from those in patients without LCS.