If a patient exhibits acute swelling and pain at the back of the knee after vein ablation, what is the most likely diagnosis?

The scenario describes a patient experiencing acute swelling and pain at the back of the knee following vein ablation, which points towards the likelihood of a Baker's cyst. A Baker's cyst, also known as a popliteal cyst, can occur when excess synovial fluid accumulates in the bursa behind the knee, often related to joint conditions that lead to increased fluid production. After vein ablation procedures, inflammation and mechanical changes around the knee joint can predispose patients to develop a Baker's cyst, leading to symptoms like swelling and discomfort in that area.

Additionally, considering the acute nature of the symptoms immediately after a surgical procedure, it aligns with how a Baker's cyst can present in relation to trauma or irritation. In contrast, conditions like deep vein thrombosis would typically present with more systemic symptoms and risk factors, while conditions such as Achilles tendonitis focus on the tendon rather than the joint area, and articular cartilage injury would often manifest with different symptoms correlating to joint dysfunction rather than localized swelling behind the knee. Thus, Baker's cyst stands out as the most plausible diagnosis in this clinical context.