Introduction of an MR-based semi-quantitative score for assessing partial meniscectomy and relation to knee joint degenerative disease: data from the Osteoarthritis Initiative
To develop an MR-based semi-quantitative meniscus scoring technique for postoperative assessment of the degree of meniscal resection, to test its reproducibility, and to study the relationship between the amount of resection and degenerative disease burden.
We studied the right knee of 135 participants from the Osteoarthritis Initiative that underwent meniscal surgery an average of 14 years previously. The amount of meniscal resection was assessed on baseline 3.0-T MRIs and calculated as meniscus resection score (MenRS) with a range of 0 to 18. Knee abnormalities at baseline and 48 months were graded using a modified Whole-Organ Magnetic Resonance Imaging Score (WORMS). Subjects were also stratified according to meniscal resection performed after injury versus without preceding injury. Statistical analysis included intra-class correlation coefficient (ICC) to determine reproducibility as well as regression models and partial correlations to correlate MenRS with WORMS outcomes.
ICC values for intra- and inter-observer reproducibility of MenRS were 0.980 and 0.977, respectively. Overall, the amount of meniscal resection showed a significant correlation with baseline WORMS grades: higher MenRS was associated with higher total WORMS grades (p = 0.004) and cartilage (p = 0.004) and ligament (p < 0.001) subscores. However, no significant association between MenRS and change in WORMS grades over 48 months was found. The relationship between MenRS and baseline WORMS grades did not change after adjusting for a reported history of knee injury.
Postoperative assessment of the knee following partial meniscectomy using the newly developed MenRS showed excellent reproducibility and significant cross-sectional correlation with WORMS gradings.
• The newly developed semi-quantitative MR-based meniscal resection score demonstrated excellent reproducibility.
• A significant correlation between the amount of meniscal resection measured using the newly developed score and the degree of overall knee joint degenerative disease and cartilage defects was found.
KeywordsPartial meniscectomy Meniscus Magnetic resonance imaging Knee osteoarthritis
Body mass index
Dual echo at steady state
Intra-class correlation coefficient
Meniscus Resection Score
Western Ontario and McMaster Universities Osteoarthritis Index
Whole-Organ Magnetic Resonance Imaging Score
We would like to thank the participants and staff of the Coordinating Center of the OAI for their invaluable assistance with patient selection, statistical analysis, and technical support.
The analyses in this study were funded through the NIH/NIAMS (National Institute of Arthritis and Musculoskeletal and Skin Diseases grants R01AR064771 and P50-AR060752). This study was also supported by grants from the National Scientific Foundation of China (NSFC, No. 31630025, 81571643, and 81320108013). The entire project was supported by the Osteoarthritis Initiative, a public–private partnership comprising 5 NIH contracts (National Institute of Arthritis and Musculoskeletal and Skin Diseases contracts N01-AR-2-2258, N01-AR-2-2259, N01-AR-2-2260, N01-AR-2-2261, and N01-AR-2-2262), with research conducted by the Osteoarthritis Initiative Study Investigators. The study was also funded in part by the Intramural Research Program of the National Institute on Aging, NIH. Private funding partners include Merck Research, Novartis Pharmaceuticals, GlaxoSmithKline, and Pfizer; the private sector funding for the Osteoarthritis Initiative is managed by the Foundation for the National Institutes of Health.
Compliance with ethical standards
The scientific guarantor of this publication is Thomas M. Link.
Conflict of interest
The authors of this manuscript declare no relationships with any companies, whose products or services may be related to the subject matter of the article.
Statistics and biometry
Gabby B. Joseph, PhD, kindly provided statistical advice for this manuscript.
Written informed consent was obtained from all subjects (patients) in this study.
Institutional Review Board approval was obtained for this study.
• Longitudinal, prospective cohort study with retrospective data analysis.
• Diagnostic or prognostic study.
• Multicenter study.
- 13.King D (1936) The function of semilunar cartilages. JBJS 18:1069–1076Google Scholar
- 26.Joseph GB, McCulloch CE, Nevitt MC et al (2017) Tool for osteoarthritis risk prediction (TOARP) over 8 years using baseline clinical data, X-ray, and MRI: data from the osteoarthritis initiative. J Magn Reson Imaging 47:1517–1526Google Scholar
- 32.Cooper DE, Arnoczky SP, Warren RF (1991) Meniscal repair. Clin Sports Med 10:529–548Google Scholar
- 45.Longo UG, Ciuffreda M, Candela V et al (2018) Knee osteoarthritis after arthroscopic partial meniscectomy: prevalence and progression of radiographic changes after 5 to 12 years compared with contralateral knee. J Knee Surg. https://doi.org/10.1055/s-0038-1646926