Leg is purple and cold 4 days after surgery

[Mother]

My son had a broken part of his Patella removed on Jan 22nd and we have noticed since yesterday his leg is discolored (purple) and it is colder than the other leg. When you touch his leg and pull your hand away it is white where you touched. Any ideas?

[Tom Plamondon PA-C]

Hello,
Thank you for writing in.

You have reported your son broke his patella on Jan 22nd. The leg is purple and cold. What does this mean?

A cold limb following a fracture is concerning because we want to make sure there is good blood flow to the limb. Swelling can compromise blood vessel flow so it is important to see a physician who can check pulses, and examine the leg.

A fractured patella itself should not cut off circulation so along with checking for good pulses, it will be prudent to xray other parts of the leg for damage - femur, tibia/fibula, etc.

The purple color may be from bruising which is an expected finding from trauma to superficial blood vessels. The purple may be due to pooling blood due to decreased mobility and poor circulation.

In essence, see a physician to re evaluate the leg.

Take care and keep us posted.