Iliac fractures are assessed based on the severity of the fracture. Generally, there are two types of iliac fractures. The first type is a linear fracture. If this linear fracture does not involve the joint surface and is a simple, non-severe linear fracture, a plaster cast can be sufficient for complete recovery, usually within about two months. The second type is a comminuted fracture, where the fracture ends affect the joint surface; in such cases, surgical treatment may be required to restore the smoothness of the joint and stabilize the fracture pieces, with a recovery time generally ranging from two to three months. Therefore, a comminuted patellar fracture is generally very serious and typically requires surgery. This is because comminuted patellar fractures are likely to lead to the most common form of post-traumatic arthritis, resulting in pain during activity later on.