Biceps femoris calcific tendinitis as a rare cause of lateral knee pain: a case report.

Introduction: Calcific tendinitis is a common cause of periarticular pain, though it rarely affects the distal biceps femoris tendon, leading to lateral knee pain. This case report highlights a rare instance of biceps femoris calcific tendinitis and its successful conservative management. Case presentation: A 40-year-old female presented with a 1-week history of sharp lateral knee pain, which worsened with movement but persisted at rest. There was no history of trauma or systemic illness. On examination, tenderness was localized to the lateral knee, specifically over the fibular head and biceps femoris tendon. Blood tests were unremarkable. Radiographs and ultrasound revealed multifocal calcifications at the fibular head. Although MRI was recommended, it was not feasible in this resource-limited setting. The patient was initially treated conservatively with NSAIDs and physiotherapy but did not respond. She subsequently underwent ultrasound-guided barbotage and corticosteroid injection, resulting in the complete resolution of symptoms within 1 week. Discussion: Calcific tendinitis is caused by the deposition of calcium hydroxyapatite crystals in periarticular tendons, leading to inflammation and pain. Biceps femoris calcific tendinitis is rare, and diagnosis can be made using cost-effective imaging modalities such as radiography and ultrasound. Conservative management, including NSAIDs, physiotherapy, and ultrasound-guided barbotage, is the preferred first-line treatment. In this case, the combination of barbotage and physiotherapy led to complete symptom relief. Conclusion: Biceps femoris calcific tendinitis, though rare, should be considered in cases of lateral knee pain. Early diagnosis and conservative treatment can result in rapid symptom relief.