Catherine Phan MD, Presenter: Nothing to Disclose

Thomas Marc Link MD, Abstract Co-Author: Nothing to Disclose

Lynne S. Steinbach MD, Abstract Co-Author: Nothing to Disclose

Gabby Blumenkrantz MS, Abstract Co-Author: Nothing to Disclose

Sharmila Majumdar PhD, Abstract Co-Author: Nothing to Disclose

Osteoarthritis (OA) of the knee affects 30% of people over age 65 and is a leading cause of disability in the elderly. The relationship in the follow-up of OA between clinical findings and those shown on MR images remains unclear. The aims of this study were (1) to assess the rate of progression of cartilage loss, the change of bone marrow edema (BME) pattern and other MR findings and (2) to correlate these findings with clinical scores of pain, stiffness and limited function.

40 recruited subjects (mean age 57.7 ± 15 years) were divided into 3 groups: healthy volunteers (OA0; n=6), mild OA (OA1; n=17) and severe OA (OA2; n=17) based on the Kellgren-Lawrence (KL) scale (KL1+KL2=OA1; KL3+KL4=OA2). Baseline (BL) assessment included MRI at 1.5T, radiographs and the clinical Western Ontario and McMaster University Osteoarthritis (WOMAC) score. At follow-up 1 (FU1) (17±8 months, n=40) and FU2 (29±5 months, n=26), MR scans and WOMAC scores were obtained. Cartilage morphology, BME, meniscal and ligamentous pathology were assessed on MRI and quantified by 2 radiologists in consensus.

At BL, 65% (11/17) of OA2 patients showed full-thickness cartilage lesions, compared to 76% (13/17) at FU1 and 70% (7/10) at FU2. During the observed interval, cartilage loss was found in 9/40 patients at FU1 and in 4/26 at FU2. BME patterns were identified in 23/40 patients at BL, 22/40 at FU1 and 13/26 at FU2. OA1 patients showed BME in 7/17 cases and in 15/17 in OA2 patients. Changes in BME area were found in 16/22 patients at FU1 and 4/13 at FU2. In 13/22 patients an increase of the area of BME was found at FU1 (average=146%) and in 4/13 patients at FU2 (average=159%). During the 2.4 years of FU there was a trend with increasing WOMAC scores for OA2 and decreasing scores for OA1. Changes in WOMAC scores over time did not correlate significantly with the amount of cartilage loss and changes in BME (P>.05).

Over a period of 17 and 29 months, only mild cartilage loss was observed, while changes in BME pattern were more pronounced. Clinical WOMAC scores, however, did not correlate significantly with the amount of cartilage loss and changes of BME.

Phan, C, Link, T, Steinbach, L, Blumenkrantz, G, Majumdar, S, MR Findings in the Follow-up of Patients with Different Stages of Knee Osteoarthritis and Correlation with Clinical Symptoms.  Radiological Society of North America 2004 Scientific Assembly and Annual Meeting, November 28 - December 3, 2004 ,Chicago IL. http://archive.rsna.org/2004/4415958.html