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related talks:  broken elbow (olecranon fracture, another type); children's broken elbowelbow dislocationelbow stiffnessbroken forearmbroken armswollen elbow

What is a Radial Head Fracture?

A radial head fracture is a type of broken elbow.

To better understand the injury, lets take a quick look at the anatomy of our elbow and forearm.  The radius bone is one of two bones in the forearm that join together with the arm bone (humerus)  to form the elbow joint.  The radial head is the portion of the bone that helps form the elbow.  A radial head fracture can occur when you fall onto your elbow, or most commonly, when you fall onto an outstretched hand (and the force of impact is transmitted up the forearm to the elbow). 

This fracture can occur as an isolated injury, but its commonly broken in combination with other injuries such as an elbow dislocation, or with a fracture of the other forearm bone (the ulna).  Therefore, its important to look out for other injuries whenever a radial head fracture is identified.

How is a Radial Head Fracture diagnosed?

Diagnosis of this injury starts when a person reports elbow pain after an injury (usually a fall). People will report limited motion in their elbow, and pain when twisting their forearm (like opening a doorknob).  

Doctors will notice tenderness along the outside of the elbow, and pain when moving the elbow.  Oftentimes the elbow is bruised and/or swollen.  

When a broken elbow is suspected, doctors will order x-rays, which will provide the diagnosis (and also will show how severe the break is).  These x-rays are used to classify the injury as a "Mason Type 1, 2, or 3".  Mason 1 is a hairline crack (the broken bone fragment doesnt move), Mason 2 the bone fragment moves >2 mm out of position, and Mason 3 is multiple breaks.  

Because this type of injury is often associated with other injuries, doctors will carefully check the ligament stability of the elbow to ensure the elbow is not loose and that it doesn’t dislocate. Its also important for a doctor to check the wrist for signs of additional injury (like a broken bone) because the forearm bones make up both the elbow and the wrist joint.

How is a Radial Head Fracture treated?

Treatment depends on the severity of the break (as seen on x-ray).  The goal of all treatment options is to prevent long term pain and stiffness.

If its just a hairline crack in the bone (aka Mason Type 1 injury), then only a sling is needed to provide comfort.

If the crack is a little bigger bigger but the broken fragment is still small (less than 1/3 of the whole radial head) than it typically heals well with just a sling, even if this small fragment moves out of position. People should begin moving the elbow within the next few days to prevent stiffness. 

Surgery is only really considered in these smaller breaks if a bone fragment somehow gets wedged in a position that blocks the elbow from its normal motion.  In this case, the small chip of bone is removed so the elbow can rotate normally.  

When the bone fragment is bigger (at least 1/3 of the radial head) and it has moved more than 2 mm out of position (Mason Type 2 injury) surgery is sometimes recommended (but this is controversial: see outcomes section).

A small screw is used to put the bone fragment back into position.  The screws give stability to the broken bone so that the elbow can start moving in physical therapy without concern that the break will get worse.  By restoring the normal shape of the radial head, doctors hope to prevent painful post-traumatic arthritis and stiffness.  

If a radial head gets "shattered", meaning there are multiple breaks (this is also called a "comminuted fracture" or a Mason Type 3 injury), the pieces of bone are often too small to put back together with screws (although sometimes it can be done by a very talented surgeon).    

In cases of a Mason Type 3 injury, sometimes the entire radial head can just be removed.  This is a treatment option best suited for elderly and low demand patients that have an otherwise stable elbow (all the elbow ligaments are intact).  The radial head gives valuable stability to the elbow joint, and so by taking it out, you risk creating elbow instability... leading to an elbow dislocation.  This is particularly true if the elbow ligaments were also torn during the injury. In fact, when the radial head is really shattered (indicating it was a high energy injury), at least one ligament is torn about 80% of the time.  

Therefore, the more common treatment for a shattered radial head, where the bone is beyond repair, is to remove all the fragments, and insert a metal replacement (you get a shiny new radial head).  This surgery is called a radial head replacement and has good outcomes.

What is the long term outcome?  

The small breaks or hairline cracks that are treated with a sling and early motion typically heal well.  These breaks are "stable injuries" and there is a very low risk that the injury will get worse by moving the elbow immediately or a few days after injury. Over 90% of people report good to excellent results, and the elbow regains full function (although it may never completely straighten out, with about 10-15 degrees of a persistent flexion contracture).  

A recent study looking at people 10 years after a Mason I or Mason 2 injury (with normal elbow stability and motion), treated with just a sling for comfort, showed that 92% were satisfied with the results, that only 2% required surgery at a later time and that only 2% continued to experience significant pain (although 24% reported some intermittent pain, and 14% reported some elbow stiffness).  These results suggest that even a more severe Type 2 injury can be effectively treated without surgery.

Surgical repair of a radial head fracture also has good outcomes.  About 80% of cases have good to excellent results with return of elbow function and near normal range of motion.  As technology gets better, smaller and smaller screws have been developed to repair bones that break into many pieces.  

Yet even with better technology some cases still require a radial head metal replacement.  Newer metals used for these replacements have shown good long term results, although some people develop arthritis in this part of the elbow probably due to the metal contact with our normal cartilage.  If the metal replacement is too big it can put too much pressure on the cartilage and accelerate this arthritis.

Lastly, the biggest concern with a radial head fractures is the risk for elbow stiffness.  Doctors push people to start moving their injured elbows as soon as possible to minimize stiffness.

A complete return to pre-injury range of motion is not always necessary. Activities of daily living do not require full elbow range of motion, rather 30 degrees to 130 degrees of flexion, and - 30° to 50° of forearm twisting (pronation-supination).  Therefore, if the elbow has motion despite the fracture, orthopedic doctors will often leave the fragments of bone alone and let them heal naturally, which may lead to some limits in range of motion, but rarely pain.  The problem with trying to repair a very smashed up radial head is that there is a high rate of nonunion (bone fails to heal) and this is painful.  Therefore a smashed up radial head is often best leave alone if the elbow moves fairly well, or to completely remove it and/or replace it, which gives people good pain free motion and stability after surgery.  


1) Duckworth AD et al.  Long-Term Outcomes of Isolated Stable Radial Head Fractures. JBJS 2014; 96: 1716-23. full article.

2) Duckworth AD, McQueen MM, Ring D. Fractures of the radial head. JBJS 2013; 95: 151-9. full article.

3) Tejwani NC, Mehta H. Fractures of the radial head and neck: current concepts in management. JAAOS 2007; 15: 380-7. full article. review.

4) Morrey BF et al. Valgus stability of the elbow. A definition of primary and secondary constraints. CORR 1991;187-195. full article. MCL is primar, radial head is secondary restraint to valgus stress. radial-capitellar joint also carries some load during gripping.

5) Greenspan A, Norman A. The radial head, capitellum view: useful technique in elbow trauma. Am J Roent 1982; 1186-11888. full article.  best look at radiocap joint.

6) Hotchkiss RN. Displaced fractures of the radial head: internal fixation or excision? JAAOS 1997; 5: 1-10. full article. modified Mason criteria.

Mason I

7) Paschos NK et al. Comparison of early mobilization protocols in radial head fractures. A prospective randomized controlled study. The effect of fracture characteristics on outcome. JOT 2013; 27: 134-9. full article. nondisp fx: immediate ROM vs 2 days sling then ROM vs 7 days cast immoblization then ROM. sling/ROM at 2 days did best.    

Mason 2

8) Zarattini G et al. The surgical treatment of isolated mason type 2 fractures of the radial head in adults: comparison between radial head resection and open reduction and internal fixation. JOT 2012; 26: 229-35. full article.

9) Furey MJ et al.  A retrospective cohort study of displaced segmental radial head fractures: is 2 mm of articular displacement an indication for surgery? J Shoulder Elbow Surg. 2013, 22: 636-41. full article. cannot rely on displacement alone as indication for surgery

9.2) Broberg MA, Morrey BF. Results of treatment of fracture-dislocations of the elbow. CORR 1987;216:109-119. full article. recommend >30% radial head for consideration as "displaced" fragment.  controversial but generally believed that marginal fragment isnt equal to central fragment.

Mason 3

10) Furry KL, Clinkscales CM. Comminuted fractures of the radial head: arthroplasty versus internal fixation. CORR 1998; 40-52. full article. review: high association btwn comminuted radial head fx and ligament injury. 

11) King GJ et al. Open reduction and internal fixation of radial head fractures. JOT 1991; 5: 21-8. full article. orif good for mason 2, poor for mason 3 (only 33% good), but only looked at 11 pt.

12) Ikeda M, Oka Y. Function after early radial head resection for fracture: a retrospective evaluation of 15 patients followed for 3-18 years. Act Ortho Scand 2000; 71: 191-194. full articleradial head resection doesnt do well long term: avg 10 yr f/u 15 pt, only 30% pain-free, 100% strength loss.   

13) Ikeda M et al. Open reduction and internal fixation of comminuted fractures of the radial head using low-profile mini-plates. JBJS Br 2003;85:1040-1044. full article. good outcome ORIF in severe comminuted fx; 90% (9/10) excellent-good. 90% req. ROH.  avg 44 yo, 70-80 supin-pron, 5-130 flex-ext.  only 1/10 fair outcome.

14) Ring D, Quintero J, Jupiter JB. Open reduction and internal fixation of fractures of the radial head. JBJS 2002; 84; 1811-1815. full article. 13/14 mason 3 had poor outcome ORIF.  all simple fx, noncomminuted fx had excellent results. orif doesnt work for comminution (>3 fragments).  conflicts with Ikeda M et al (above)

15) Ashwoood N et al. Management of Mason type III radial head fractures with a titanium prosthesis, ligament repair, and early mobilization. JBJS 2004; 86: 274-80. full article. radial head arthroplasty works well (esp if done early). 13/16 excellent-good outcome, avg 15-130 flex-ext, 65-70 supin-pron. 


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