Pes Anserine Bursitis: An Underrecognized Cause of Medial Knee Pain - A Review of Diagnosis, Associated Conditions, and Evidence-Based Management.

Pes anserine bursitis (PAB) is a frequently underrecognized and misdiagnosed cause of medial knee pain. It occurs when there is inflammation of the bursa interposed between the conjoined pes anserine tendons and the underlying proximal tibia. The purpose of this review is to describe the current knowledge regarding the diagnosis and management of PAB by providing an evidence-based overview of clinical exams and treatment modalities. PAB is prevalent across several high-risk populations, including knee osteoarthritis (OA), obesity, type 2 diabetes mellitus, and athletes engaged in repetitive knee flexion activities. Diagnosis is currently limited by the absence of a validated quantitative clinical assessment tool. The main goal of treatment is to reduce associated bursal inflammation and address the underlying biomechanical and systemic contributing factors. The standard of care is conservative intervention, comprising rest, ice, and short-term NSAID use, then physical therapy and, where symptoms persist, intrabursal corticosteroid injection, with response commonly assessed at eight weeks. Surgery is considered only after these measures have been exhausted. Due to the complexity of overlapping medial knee pathology and the absence of a gold-standard diagnostic method, PAB remains a clinical diagnosis that requires thoughtful history-taking, physical examination, and selective use of imaging. This review summarizes essential clinical examination techniques and treatment options for PAB, emphasizing practical recommendations for orthopedic surgeons. The intended audience also includes sports medicine physicians, rehabilitation specialists, and primary care providers, as most cases are managed conservatively. Referral to orthopedic surgery is appropriate only when symptoms persist despite comprehensive conservative therapy. Although PAB is often diagnosed clinically, structural bursitis is confirmed in only a minority of cases, so management relies primarily on clinical assessment rather than imaging findings.