Alshahrani AS, Aljaffar AB, Albin Ahmed BJ, Altabash MW, Dajani ZA, Alamer AH, Alzawad AJ, Alanii F, Alzahrani MM. Correlation between Kellgren-Lawrence classification of osteoarthritis and Knee Injury and Osteoarthritis Outcome Score. World J Orthop 2025; 16(11): 111953 [DOI: 10.5312/wjo.v16.i11.111953]
Corresponding Author of This Article
Baqir Jafar Albin Ahmed, MBBS, College of Medicine, Imam Abdulrahman Bin Faisal University, King Faisal Road, Dammam 34212, Saudi Arabia. baqer23jafar@gmail.com
Research Domain of This Article
Orthopedics
Article-Type of This Article
Observational Study
Open-Access Policy of This Article
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/
World J Orthop. Nov 18, 2025; 16(11): 111953 Published online Nov 18, 2025. doi: 10.5312/wjo.v16.i11.111953
Correlation between Kellgren-Lawrence classification of osteoarthritis and Knee Injury and Osteoarthritis Outcome Score
Ali Saad Alshahrani, Abdullah Bader Aljaffar, Baqir Jafar Albin Ahmed, Mohammad Waleed Altabash, Zaid A Dajani, Ali Hussein Alamer, Abdulaziz Jamal Alzawad, Fawaz Alanii, Mohammad M Alzahrani
Ali Saad Alshahrani, Fawaz Alanii, Department of Orthopedic Surgery, King Fahad University Hospital, Khobar 34445, Saudi Arabia
Abdullah Bader Aljaffar, Baqir Jafar Albin Ahmed, Mohammad Waleed Altabash, Zaid A Dajani, Ali Hussein Alamer, Abdulaziz Jamal Alzawad, College of Medicine, Imam Abdulrahman Bin Faisal University, Dammam 34212, Saudi Arabia
Mohammad M Alzahrani, Department of Orthopedic, College of Medicine, Imam Abdulrahman Bin Faisal University, Dammam 34212, Saudi Arabia
Author contributions: Alshahrani AS supervised the research design, provided critical revisions, and approved the final version; Aljaffar AB designed the study protocol, coordinated the project, and drafted the initial manuscript; Albin Ahmed BJ contributed to patient recruitment, data collection, and clinical assessments; Altabash MW performed statistical analysis and data visualization; Dajani ZA contributed to data collection, literature review, and manuscript drafting; Alamer AH assisted in patient evaluation and contributed to data acquisition; Alzawad AJ participated in data management, literature search, and manuscript editing; Alanii F provided senior oversight, methodological guidance, and critical manuscript review; Alzahrani MM contributed to research methodology refinement and final manuscript approval; all authors read and approved the final manuscript.
Institutional review board statement: The study was reviewed and approved by the Institutional Review Board of Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia (No. IRB-UGS-2024-01-786; approval date: October 29, 2024).
Informed consent statement: Informed written consent was obtained from all participants.
Conflict-of-interest statement: The authors declare that they have no conflict of interest.
STROBE statement: The authors have read the STROBE Statement–checklist of items, and the manuscript was prepared and revised according to the STROBE Statement–checklist of items.
Data sharing statement: The data supporting the findings of this study are available from the corresponding author (alisaad1431@gmail.com) upon reasonable request.
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: Baqir Jafar Albin Ahmed, MBBS, College of Medicine, Imam Abdulrahman Bin Faisal University, King Faisal Road, Dammam 34212, Saudi Arabia. baqer23jafar@gmail.com
Received: July 15, 2025 Revised: August 10, 2025 Accepted: September 25, 2025 Published online: November 18, 2025 Processing time: 122 Days and 12.8 Hours
Abstract
BACKGROUND
Osteoarthritis (OA) is a common degenerative joint disease that considerably affects the quality of life (QoL) of individuals, especially the elderly. The Kellgren-Lawrence (KL) grading system assesses the severity of OA through radiographic evaluation, whereas the Knee Injury and Osteoarthritis Outcome Score (KOOS) measures clinical symptoms and functional status.
AIM
To analyze the relationship between KL grades and KOOS to elucidate the association between radiographic severity and clinical manifestations of knee OA.
METHODS
A cross-sectional study was performed at King Fahd Hospital of the University, involving 164 adult patients diagnosed with knee OA. Patients were evaluated using the KL system, based on standing knee X-rays performed within the last six months. The KOOS questionnaire was utilised for clinical assessment, evaluating five domains: (1) Pain; (2) Symptoms; (3) Activities of daily living; (4) Sport and recreation function; and (5) Knee-related QoL. Analysis of variance was utilised to examine variations in KOOS domain scores among different patient variables. The correlations between KOOS domains were determined using Pearson's correlation.
RESULTS
KOOS scores demonstrated a significant decline in patients with elevated KL grades, with Grade 4 exhibiting the lowest scores and grade 1 the highest (P < 0.001). The correlation between pain and activities of daily living was strong (r = 0.871, P < 0.001), as was the correlation with knee-related QoL (r = 0.754, P < 0.001). Notable age-related disparities were observed, as older patients (≥ 60 years) indicated poorer pain and functional outcomes. Gender differences were noted exclusively in symptoms, with females exhibiting lower scores than males (P = 0.022).
CONCLUSION
The association between radiographic severity and clinical impact is shown by the substantial correlation between KL grading and KOOS results, especially in later stages of OA. The results highlight the necessity for thorough assessments that integrate radiographic and clinical evaluations for individualized therapy choices for OA patients.
Core Tip: This cross-sectional study explores the relationship between radiographic severity and clinical outcomes in knee osteoarthritis using the Kellgren-Lawrence (KL) grading system and the Knee Injury and Osteoarthritis Outcome Score (KOOS). Findings show that patients who have scored grade 4 in the KL radiographic scale had significantly lower KOOS scores across all domains, especially pain and activities of daily living. Pain was strongly associated and observed with both functional limitations and quality of life. Age, gender, and obesity influenced the outcomes. These findings highlight the necessity of the integration of radiographic opinions and patient-reported outcomes to enhance OA management.
