Arthritis & Rheumatism, Volume 63,
November 2011 Abstract Supplement

Abstracts of the American College of
Rheumatology/Association of Rheumatology Health Professionals
Annual Scientific Meeting
Chicago, Illinois November 4-9, 2011.


Progression of the MRI-Detected Osteoarthritis Features in Radiographic End-Stage Knee Osteoarthritis (Kellgren-Lawrence grade 4) - the Multicenter Osteoarthritis Study.

Guermazi1,  Ali, Hayashi1,  Daichi, Roemer1,  Frank, Felson1,  David T., Wang1,  Ke, Lynch2,  John, Amin3,  Shreyasee

Boston University, Boston, MA
UCSF, San Francisco, CA
Mayo Clinic, Rochester, MN
University of Iowa, Iowa City, Iowa City, IA
University of Alabama, Birmingham City, AL
University of California-San Francisco, San Francisco, CA

Background/Purpose:

Kellgren-Lawrence grade 4 (KL4) knees are considered radiographic 'end-stage' knee OA (bone-on-bone appearance) which theoretically does not progress further. We evaluated what proportion of KL 4 knees at baseline demonstrate further progression longitudinally in regard to features only detectable by MRI, i.e. cartilage, bone marrow lesion (BML), meniscus, Hoffa-synovitis, and effusion-synovitis.

Methods:

We studied subjects from the Multicenter Osteoarthritis Study who had KL4 knees at baseline and had baseline and 30-month MRI. Cartilage, BML, meniscus, Hoffa-synovitis, and effusion-synovitis were semiquantitatively scored using the WORMS system in the 5 subregions of the medial and lateral tibiofemoral (TF) compartments of the knee: central and posterior femoral, anterior, central and posterior tibial subregions. WORMS cartilage grading ranges from 0 – 6 where 6 represents full-thickness cartilage loss in >75% of the subregion. Analysis was performed for the compartment showing bone-on-bone appearance ("index") on radiograph and also for the other TF compartment of the same knee. Hoffa-synovitis and effusion-synovitis were assessed for the whole knee. Changes in scores at follow-up were noted for each feature. For cartilage and BML, within-grade changes were also recorded.

Results:

63 subjects (67 knees) were included (51% women, 84% White, mean age 65.1±8.6 years, mean BMI 30.2±5.2 kg/m2). At baseline, in the index TF compartment, all knees showed severe cartilage loss (max WORMS score from 5 subregions was 5 in 1 knee and 6 in 66 knees), 54 knees (80%) showed moderate to large BMLs (max WORMS score 2 or 3), and 62 knees (94%) had severe meniscal lesions (i.e. displaced tear or maceration). In the other TF compartment, 12 knees (18%) had severe cartilage loss, but 47 (71%) had no BML and 57 (97%) had no meniscal damage. 39 knees (58%) had moderate to severe effusion-synovitis, 56 knees (86%) had mild or moderate Hoffa-synovitis. Longitudinally, 22 index compartments (35%) showed an increase in the sum of cartilage scores from all subregions, and 2 (3%) showed increase in the maximum cartilage score. In the other TF compartment, 22% showed an increase in the sum score for cartilage damage, while 15% showed increase in maximum score. For BMLs in the index TF compartment, 19 knees (31%) showed an increase in maximum score and 11 (18%) showed a decrease. Fluctuation of BMLs was also seen in the other TF compartment, but to a lesser extent. Meniscal status mostly remained the same in the index (98%) and other TF (95%) compartments. Effusion-synovitis worsened in 15 knees (27%) and improved in 2 knees (4%). Hoffa-synovitis worsened in 6 knees (11%) and improved in 2 knees (4%).

Conclusion:

In KL4 knees, MRI detected progression of cartilage loss, and fluctuation of effusion-synovitis, Hoffa-synovitis and BMLs was observed over a 30-month period. Meniscal damage remained stable. Our findings support the idea that disease progression still occurs in KL4 knees. KL4 knees can be a potential target for assessing therapeutic interventions and should not necessarily be excluded from clinical trials.

To cite this abstract, please use the following information:
Guermazi, Ali, Hayashi, Daichi, Roemer, Frank, Felson, David T., Wang, Ke, Lynch, John, et al; Progression of the MRI-Detected Osteoarthritis Features in Radiographic End-Stage Knee Osteoarthritis (Kellgren-Lawrence grade 4) - the Multicenter Osteoarthritis Study. [abstract]. Arthritis Rheum 2011;63 Suppl 10 :960
DOI:

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