A pattern fracture, also known as a butterfly fracture, is a specific type of bone fracture characterized by a non-displaced crack in the bone, often the patella. The bone cracks but remains in one piece, resembling a butterfly with its wings spread. These fractures typically result from a direct blow to the knee, such as a fall or impact during sports. Diagnosis is usually confirmed through X-ray imaging. Treatment varies depending on the severity of the fracture, ranging from immobilization in a cast or brace for non-displaced fractures to surgical intervention with wires or screws for more severe cases. Rehabilitation is crucial to regain full knee function.

Pattern fractures are not directly related to pancreatic cancer or its treatment. However, cancer patients, including those with pancreatic cancer, can be at risk for fractures due to complications like metastasis or osteoporosis, which are indirect consequences of the disease or its treatment.