Baker's cyst

A fluid-filled swelling behind the knee, usually secondary to another knee problem.

Overview

A Baker's cyst is a fluid-filled swelling at the back of the knee, often arising when an underlying problem such as arthritis or a meniscus injury increases fluid in the joint. Treating the underlying cause usually helps.

Symptoms

  • A swelling or tightness behind the knee
  • Discomfort with full bending
  • Sometimes calf swelling if it leaks
  • Symptoms linked to an underlying knee problem

Causes

  • Knee osteoarthritis
  • Meniscus or cartilage injury
  • Anything increasing joint fluid

Treatment

  • Treating the underlying knee problem
  • Activity modification and pain management
  • Aspiration or injection in some cases
  • Medical review if a clot is suspected