Frank W. Roemer MD, Presenter: Shareholder, Boston Imaging Core Lab, LLC

Zineb Dhina MD, PhD, Abstract Co-Author: Nothing to Disclose

Kent Chian Kwoh MD, Abstract Co-Author: Nothing to Disclose

Michael Hannon, Abstract Co-Author: Nothing to Disclose

Carolyn E. Moore MD, PhD, Abstract Co-Author: Nothing to Disclose

Ali Guermazi MD, Abstract Co-Author: Stockholder, Synarc, Inc President, Boston Imaging Core Lab, LLC Research grant, General Electric Company Research Consultant, Merck KGaA

Aim of the study was to describe prevalence of intra- and periarticular cystic lesions of the knee in patients with frequent knee pain and to observe these lesions over a period of six months.

The Joints On Glucosamine (JOG) Study includes 177 subjects aged 35-65 (95 men and 82 women) with chronic, frequent knee pain. 3 T MRI (sagittal IW fat suppressed, triplanar DESS, coronal IW sequences) of both knees was performed at baseline and at 6-months follow-up. The following cystic lesions were assessed: Baker’s cysts, medial and lateral meniscal cysts, ACL- and PCL-cysts, semimembranous ganglia, prepatellar-, superficial- and deep-infrapatellar bursitis, Hoffa’s cysts, tibio-fibular joint cysts, pes anserine-, medial collateral ligament-, iliotibial band- and gastrocnemius-bursae. Cysts were measured to the nearest millimeter in the maximum diameter. In addition, the incidence of new cysts or change in size (increase/decrease) over 6 months were noted. We analyzed prevalence of cysts in relation to radiographic Kellgren-Lawrence grade by the Cochran-Armitage Trend Test.

319 knees (158 right and 161 left knees in 156 patients) were assessed. 222 (69.6%) of all knees showed at least one cyst. The most common cystic lesions were Baker’s cysts (128 knees / 40.1%) followed by gastrocnemius bursitis (49 / 15.3%), tibio-fibular joint cysts (26 / 8.1%) and Hoffa’s cysts (25 / 7.8%). The other types of cysts were less frequent. 74% of the Bakers cysts increased or decreased in size, while the other cysts did not show relevant variation in size. Prevalence of any cystic lesions increased with K/L grade (K/L 0: 57%, K/L 1: 78%, K/L 2: 81%, K/L 3: 72%, K/L 4: 94%, p < 0.004) with similar results by specific type of cyst (p < 0.05). 22% of subjects showed bilateral Baker’s cysts and 7% bilateral gastrocnemius bursae. No significant differences in age, gender and body mass index between patients with and without were observed.

Cystic lesions around the knee joint are common and are increasingly observed with higher grades of osteoarthritis. Baker’s cysts are the most common cystic lesions followed by gastrocnemius bursa, tibiofibular joint and Hoffa’s cysts.

Cystic lesions around the knee are common and may be a source of symptoms. Radiologists should be aware that prevalence of cystic lesions increases with severity of radiographic OA status.

Roemer, F, Dhina, Z, Kwoh, K, Hannon, M, Moore, C, Guermazi, A, Prevalence of Intra- and Periarticular Cystic Lesions of the Knee in Knees with and without Radiographic Osteoarthritis and Longitudinal Assessment over Six Months Using 3T MRI.  Radiological Society of North America 2009 Scientific Assembly and Annual Meeting, November 29 - December 4, 2009 ,Chicago IL. http://archive.rsna.org/2009/8004322.html