Case Control Study
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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
ARTICLE HIGHLIGHTS
Research 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.

Research motivation

The research is motivated due to high footfall of these patient on Orthopedic outpatient department. An interdepartmental meeting was made to analyze these patients and funds were provided by the institute.

Research objectives

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

Research 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.

Research results

Of the total, we selected 74 patients. The number of patients in the LCS and non-LCS groups was 34 and 40, respectively. The mean ± standard deviation of age of presentation in the LCS and non-LCS groups was 49.2 ± 8.9 and 43.1 ± 14.3 years, respectively. The difference in fibrosis (P = 0.002), elastic fiber degeneration (P = 0.01), elastic fragmentation percentage (66.5% ± 16.3% vs 29.5% ± 16.9%), elastic content percentage (26.9% ± 6.7% vs 34.7% ± 8.4%), collagen content percentage (63.6% ± 10.4% vs 54.9% ± 6.4%), reduction of elastic/collagen ratio (0.4 ± 0.1 vs 0.6 ± 0.1), and ligamentocyte number (39.1 ± 19.1 vs 53.5 ± 26.9) between the LCS and non-LCS groups was statistically significant. The difference in calcification (P = 0.08) and Pearson’s correlation between duration and loss of elastin was statistically nonsignificant. Subgroup analysis exhibited a consistent difference in LF morphology in patients aged ≥ 40 years between the two groups. A similar finding was observed in patients aged < 40 and > 40 years in the non-LCS group.

Research conclusions

The quality change in elastin fibers and an increase in the collagen content and fibrosis cause loss of elasticity in LF, contributing to LCS pathogenesis. However, calcification did not play a significant role in LCS pathogenesis.

Research perspectives

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