Pes anserine bursitis: incidence in symptomatic knees and clinical presentation.

OBJECTIVE: To determine the prevalence and associated clinical symptoms of pes anserine bursitis in symptomatic adult knees.

MATERIALS AND METHODS: A retrospective review was performed of the reports of 509 knee MRI studies obtained from July 1998 to June 2004 on 488 patients presenting to an orthopaedic clinic with knee pain suspected to be due to internal derangement. The MRI studies and case histories of all patients reported to have pes anserine bursitis were reviewed. The management of these patients was also noted.

RESULTS AND CONCLUSIONS: The prevalence of pes anserine bursitis as detected on MRI is 2.5%. The commonest clinical presentation was pain along the medial joint line mimicking a medial meniscal tear. We suggest that an accurate diagnosis of pes anserine bursitis on MRI will help prevent unnecessary arthroscopy and possibly initiate early treatment of the condition. Axial imaging is important in these cases to differentiate the bursa from other medial fluid collections.