Comminuted Fracture

What Is It, Examples, and More

Author:Corinne Tarantino, MPH

Editors:Alyssa Haag,Ian Mannarino, MD, MBA,Kelsey LaFayette, DNP, RN

Illustrator:Jessica Reynolds, MS

Copyeditor:Sadia Zaman, MBBS, BSc

What is a comminuted fracture?

A comminuted fracture describes a bone that has been broken in three or more places. In general, if a bone is broken in more than four places it can be considered highly comminuted. Comminuted fractures include a complete fracture of the bone, unlike other types of fractures, like a greenstick fracture, which is when a bone cracks, but does not completely separate. 

Comminuted fractures most commonly occur in the long bones of arms and legs and are often accompanied by pain and limited movement of the fractured bone. Depending on the location of the fracture, surrounding tissue or organs can be damaged. For instance, a comminuted fracture of one or more ribs can cause a pneumothorax (i.e., air around the lungs) if a piece of bone penetrates the pleural space of the lung. Sometimes, comminuted fractures of extremities can cause internal bleeding, which increases the pressure in the surrounding muscles, inducing compartment syndrome, which is a painful condition where pressure within muscles increases to dangerous levels. Left untreated, this can cause death to surrounding tissue, and therefore requires immediate medical attention. 

Illustration of a tibia-fibula with a comminuted fracture.

What causes a comminuted fracture?

Most commonly, comminuted fractures occur as a result of trauma. Bone requires a lot of force to break in multiple places, therefore, trauma that results in a comminuted fracture is usually severe, as occurs in a motor vehicle accident or falls from a great height. Individuals with conditions that weaken bones, such as osteoporosis,  are more likely to experience a comminuted fracture from a trauma with less force.

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How is a comminuted fracture repaired?

The first step to repairing a comminuted fracture is diagnosis with physical examination followed by imaging, such as an x-ray, to confirm the fractures.

Repairs for a comminuted fracture depend on the bone that is fractured and the type of fracture. However, most do require surgery. Typically, surgery involves open reduction where the bones are put back in place and fixated internally with screws and rods. 

After surgery, an individual will need to wear a splint or cast for several weeks to months to reduce mobility of the bone as it heals. Physical therapy is often recommended to improve muscle strength around the fractured area.

What are the most important facts to know about a comminuted fracture?

A comminuted fracture is where broken bones fracture into more than three separate pieces. It is typically caused by a severe trauma, such as a motor vehicle accident. They are often repaired by open reduction and internal fixation during surgery, followed by casting and physical therapy.

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Related links

Bone disorders: Pathology review

Resources for research and reference

Parks, E. (2017). Fracture management. Practical Office Orthopedics. McGraw-Hill.

Rudloff, M. I. (2021). Fractures of the Lower Extremity. In Azar, F. M., Beaty, J. H. & Canale, S. T. (Eds.) Campbell’s Operative Orthopaedics (14th ed.). Elsevier.

Smith, W. R., Stahel, P. F., Suzuki, T., & Gabrielle, P. (2014). Musculoskeletal Trauma Surgery. In Skinner, H. B., & McMahon, P. J. (Eds.), Current Diagnosis & Treatment in Orthopedics, (5th ed.).  McGraw-Hill.

Sop, J. L., & Sop, A. (2021, August 14). Open Fracture Management. In StatPearls [Internet]. Retrieved from