Structural tissue damage and 24-month progression of semi-quantitative MRI biomarkers of knee osteoarthritis in the IMI-APPROACH cohort

Abstract

Background The IMI-APPROACH cohort is an exploratory, 5-centre, 2-year prospective follow-up study of knee osteoarthritis (OA). Aim was to describe baseline multi-tissue semiquantitative MRI evaluation of index knees and to describe change for different MRI features based on number of subregion-approaches and change in maximum grades over a 24-month period. Methods MRIs were acquired using 1.5 T or 3 T MRI systems and assessed using the semi-quantitative MRI OA Knee Scoring (MOAKS) system. MRIs were read at baseline and 24-months for cartilage damage, bone marrow lesions (BML), osteophytes, meniscal damage and extrusion, and Hoffa- and effusion-synovitis. In descriptive fashion, the frequencies of MRI features at baseline and change in these imaging biomarkers over time are presented for the entire sample in a subregional and maximum score approach for most features. Differences between knees without and with structural radiographic (R) OA are analyzed in addition. Results Two hundred eighty-nine participants had readable baseline MRI examinations. Mean age was 66.6 ± 7.1 years and participants had a mean BMI of 28.1 ± 5.3 kg/m2. The majority (55.3%) of included knees had radiographic OA. Any change in total cartilage MOAKS score was observed in 53.1% considering full-grade changes only, and in 73.9% including full-grade and within-grade changes. Any medial cartilage progression was seen in 23.9% and any lateral progression on 22.1%. While for the medial and lateral compartments numbers of subregions with improvement and worsening of BMLs were very similar, for the PFJ more improvement was observed compared to worsening (15.5% vs. 9.0%). Including within grade changes, the number of knees showing BML worsening increased from 42.2% to 55.6%. While for some features 24-months change was rare, frequency of change was much more common in knees with vs. without ROA (e.g. worsening of total MOAKS score cartilage in 68.4% of ROA knees vs. 36.7% of no-ROA knees, and 60.7% vs. 21.8% for an increase in maximum BML score per knee). Conclusions A wide range of MRI-detected structural pathologies was present in the IMI-APPROACH cohort. Baseline prevalence and change of features was substantially more common in the ROA subgroup compared to the knees without ROA. Trial Registration Clinicaltrials.gov identification: NCT03883568.

Machine-learning predicted and actual 2-year structural progression in the IMI-APPROACH cohort

“…Also, 18–24% of patients in the OAI showed SDC-based 2-year MRI cartilage thickness progression in the OAI, compared to 38% in the current study ( 23 ). MOAKS scoring progression was higher in the OAI though, although they counted within-grade changes as well, which were not considered progression in the current study ( 11 , 24 ). Also, MOAKS readings in the OAI are only available for highly selected subsamples based on different outcomes ( 24 ).…”

“…Statistical evaluation of 2-year changes in JSW, changes and test-retest precision of qMRI, and changes and reliability of MOAKS scoring have been performed and published previously ( 6 , 10 , 11 ). Logistic regression was used to evaluate whether the s-score could predict actual structural progression; the s-score was first rescaled from 0–1 to 0–10, so that the odds ratios correspond with a 0.1 increase in s-score.…”

“…Further, previous studies generally developed and evaluated models using only one (structural) OA characteristic, usually JSW. A multitude of structural OA parameters were collected in the IMI-APPROACH cohort, including additional radiographic measures and a spectrum of magnetic resonance imaging (MRI) assessments including bone and cartilage measures, which can all be used for evaluation of progression (prediction) ( 10 , 11 ).…”

Approaches to optimize analyses of multidimensional ordinal MRI data in osteoarthritis research: A perspective

“…2 . Compartment specific vs. whole knee: Cartilage morphology, BMLs, and osteophytes may be summarized over the whole joint, or separately for the medial femorotibial joint (MFTJ), lateral femorotibial joint (LFTJ), and patella-femoral joint (PFJ) [ 24 ]. For example, by counting the number of subregions with BML for the whole knee (range: 0 to 14) or in each compartment separately (range: 0 to 5 in the LFTJ and MFTJ, 0 to 4 in the PFJ) or by calculating the delta-sum across all SR in the whole knee or in each compartment separately, as shown in Roemer et al.…”

“…The original MOAKS description does not specify how to sort the different meniscal pathologies in regard to ordinal fashion based on severity but only considers presence vs. absence of a specific tear or pathology. Past analyses have defined the following order: normal, meniscal signal, any tear type, any maceration [ 16 , 24 ]. Complete and progressive partial maceration is considered worse than partial maceration [ 14 ].…”