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What Is a Patellar Fracture? 

A patellar fracture is a break of the kneecap, the proper name for which is the patella. The kneecap sits in front of the knee joint and acts as a shield for it. A fracture can happen in any spot on the kneecap—the upper portion, the middle portion or the lower portion—where it can break cleanly into two pieces or shatter into many. 

There are a number of different types of fractures, such as: 

  • Stable: The broken pieces are still aligned. 

  • Displaced: The broken pieces are not aligned. 

  • Comminuted: The kneecap has broken into three or more pieces; this type of fracture can be stable or displaced. 

  • Open: The bone is protruding through the skin or other soft tissue. 


Patellar fractures are very painful and can even be debilitating, preventing the injured person from walking. Sometimes the knee cannot be straightened at all. There may also be bruising or swelling on and around the knee. 


A patellar fracture is usually caused by a direct injury, such as landing directly on the knee or receiving a blow to the knee. 

It can also be the result of an indirect injury. One of the most common is a fall where the person lands on the feet. This causes the quadriceps muscle to contract strongly and suddenly, which may lead to a patellar fracture or a quadriceps tendon rupture


The doctor will want to hear about any injuries that may have caused the fracture, as well as perform a physical examination. Often, the fracture can be felt beneath the skin. 

X-rays, which provide images of dense structures such as bones, are particularly useful in diagnosing fractures. An X-ray can determine the presence and severity of a patellar fracture. 


Sometimes a stable fracture can be treated nonsurgically. In that case, the fractured knee will be immobilized with a cast or splint. It is likely that weight cannot be borne on the fractured knee, so crutches, a cane or a walker may be necessary. 

Displaced, comminuted or open fractures usually require surgery. The surgeon will reattach the broken pieces to each other using pins, screws, plates or wires. In some comminuted fractures, small bone fragments may need to be removed. 

After the surgery, pain can be managed using a combination of rest, ice and medication. Physical therapy (PT) will probably be necessary, especially if the knee must be immobilized for a long period. The goals of PT exercises are to increase the range of motion of the knee and to strengthen the surrounding muscles. 


If you have an injury to the patella, follow the link below and answer a few short questions. Someone will get back to you as soon as possible. Thank you for choosing Summit Health. 

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