A patellar sleeve fracture is a rare knee injury that occurs in young athletes. Usually resulting from a noncontact mechanism, a small piece of bone and cartilage pulls off the lower part of the patella. These are painful injuries that often require surgery for the athlete.
Diagnosis and treatment of a patellar sleeve fracture
X-rays can often demonstrate the small bony fragment pulled off the lower portion of the patella, but it can be hard to see. An MRI or ultrasound can demonstrate the injury.
If the fragment is nondisplaced and the young athlete can lift his leg off the ground or table, then he might not need surgery. The surgeon would likely place him in a cast for many weeks until the fracture heals.
If the fragment is displaced, then surgery to put it back into place and hold it until it heals is needed. Recovery and return sports could require many months.