I have chondomalacia grade 2 of my radius. i had a coronoid fracture and subluxion of the elbow 7 months ago. would this cause it ?

Trauma: Traumatic chodromalia is well problem to effect any joint and the elbow is one of them.

Yes: One of the problems with a dislocation or subluxation of a joint, is that you can develop arthritis down the road (chondromalacia).

Chondromalacia: or softening of the Cartlidge at the end of the bone is the diagnosis is usually made in the joint with an arthroscopy. Ligament injuries or subluxations in the elbow can certainly affect the Cartlidge surface. However many people who never have an injury also have chondromalacia. So it's quite possible that it has nothing to do with the injury. It's a good topic to talk about with your surgeon

Potentially: Yes, potentially. Chondromalacia is a condition where the cartilage is abnormal, this could potentially have been a posttraumatic condition related to your injury.