Cystic degeneration of the patella after arthroscopic chondroplasty and subchondral bone perforation.

Chondromalacia of the patella is frequently encountered in patients with anterior knee pain. Arthroscopic chondroplasty with perforation of subchondral bone remains a popular treatment alternative in spite of the inferior mechanical properties of the fibrocartilaginous tissue that this procedure is designed to promote. We report a case of cystic degeneration of the patella as a previously unrecognized complication following the procedure.