The prevalence of periarticular lesions detected on magnetic resonance imaging in middle-aged and elderly persons: a cross-sectional study

BACKGROUND Previous studies showed that among persons with radiographic knee OA, periarticular lesions were significantly more common among participants with knee pain than those without. However, data were derived mostly from persons with knee OA, and there were few normal participants without knee OA in the data analyses. The objectives of this study were to investigate the prevalence of periarticular lesions detected by magnetic resonance imaging (MRI), and to examine their prevalence according to the presence of knee pain and radiographic knee osteoarthritis (OA) in community residents in Korea. METHODS Demographic and knee pain data were obtained by questionnaire from 358 participants of the population-based Hallym Aging Study who were recruited irrespective of the presence of knee OA or pain. Radiographic evaluations consisted of weight-bearing knee anteroposterior radiographs and 1.5-T MRI scans. Periarticular lesions included prepatellar or anserine bursitis, Baker's cyst, and tibiofibular cyst. The prevalence of each lesion in subjects with knee OA or knee pain compared to those without was examined by a chi-square test. RESULTS The mean age of the subjects was 72 years and 50.6% were female. Radiographic knee OA was present in 34.5%. The most prevalent peri-articular lesion was Baker's cyst (27.9%), followed by tibiofibular cyst (9.5%). Anserine bursitis and tibulofibular cyst were more common in subjects with knee OA (17.5% vs 2.2% for anserine bursitis, 15.8% vs 6.1% for tibiofibular cyst in subjects with and without OA, respectively), while Baker's cyst and anserine bursitis were more common in subjects with knee pain (36.3% vs 21.8% for Baker's cyst, 14.4% vs 2.5% for anserine bursitis in subjects with and without knee pain, respectively). CONCLUSIONS Periarticular lesions on MRI of the knee are common in middle-aged and elderly persons. Anserine bursitis and Baker's cysts are more common in subjects with knee pain compared to those without.