Did you know that it’s possible to break your kneecap? This is called a patellar fracture. This type of fracture sometimes happens without the patient even knowing. Doctors became aware of this problem while taking X-rays after knee replacement surgery. About half of the patients with patellar fractures didn’t have any pain or symptoms. Only a small number of patients had moderate to severe pain from fracture.
It’s not clear what causes these fractures after knee replacement surgery. Patellar fractures could result from the condition of the bone or the amount of bone removed during knee replacement surgery. Fractures could also result from poor alignment of the kneecap and the leg bone.
The treatment depends on the type of fracture. Patellar fractures are Type I, II, or III, depending on the condition of the bone and attached muscle, and the presence of loose pieces. Type I can be treated without surgery. This is called nonoperative treatment. Types II and III usually require surgery to repair or remove the bone.
Less than one percent of patients have patellar fractures after knee replacement surgery. However, more adults are having this surgery. This means more patellar fractures will probably be seen in the future.