Right lower limb oedema

A 65-year-old construction worker with right lower limb oedema visits the hospital. He talks about how his lower limb oedema throughout the previous week coincided with his knee swelling on occasion. The ultrasound allegedly revealed a Baker cyst in the back of his knee. Thirteen years ago, he underwent a total right knee replacement. He acknowledges that his left knee has periodically bothered him during the past few years, but he has ignored the pain due to his busy schedule at work. Physical examination reveals knee effusion and pitting oedema in the right lower leg (1+, up to 2 mm of depression). He shows no oedema in his left leg, and both lower limbs have robust ankle pulses; radiographs are ordered.