Overview
what it is and why it mattersA humeral shaft fracture is a break in the long middle section of your upper arm bone (the humerus). These fractures happen from direct blows, falls, or sudden twisting forces. The clinically important feature: the radial nerve wraps closely around the humerus in a groove on the back side. About 10 to 15 percent of these fractures stretch or pinch the nerve, which causes wrist and finger drop (you cannot lift your wrist or fingers up). Almost all of these nerve injuries are temporary and recover on their own over weeks to months as the fracture heals. Most humeral shaft fractures themselves heal successfully in a functional brace, without surgery.
Symptoms
what patients describeYou will know something is wrong immediately: sudden severe pain in the middle of your upper arm, swelling that comes on fast, and often a visible bend or deformity in the arm. Moving the arm or rotating it reproduces a deep grinding sensation. Bruising typically tracks down the inner arm toward the elbow over the first day or two as blood settles with gravity.
The key symptom to report: if you cannot lift your wrist or straighten your fingers (called wrist drop), the radial nerve has been stretched or pinched where it wraps around the back of the bone. This happens in roughly 10 to 15 percent of humeral shaft fractures and is almost always temporary (the nerve recovers on its own as the fracture heals), but your surgeon needs to know about it right away so it can be tracked.
Diagnosis
exam first, imaging secondThe diagnosis usually declares itself: upper arm pain, swelling, often a visible deformity, and grinding when the bone ends move. A careful nerve exam is essential: your surgeon will specifically check that you can lift your wrist and fingers, spread your fingers, and feel sensation in all areas of the hand. Front and side X-rays of the humerus confirm the fracture. A CT scan is added when the fracture is around an existing implant or when the bone looks abnormal (suggesting an underlying tumor or weakness).
How We Treat It
brace first, in orderThe good news comes first: most humeral shaft fractures heal without surgery. The plan below moves in order, each step building on the one before it. The goal is to hold the bone in good alignment while still letting your nearby joints move, so the arm does not stiffen up while the bone knits.
1
Settle the Swelling
For the first few days you wear an initial splint. This calms the early swelling and protects the arm before the longer-term brace goes on.
2
Functional Humeral Brace (Sarmiento)
Once the swelling settles, a custom plastic brace (the Sarmiento brace) wraps around the upper arm. It keeps the bone aligned while still letting your elbow and shoulder move, which is what keeps the arm from getting stiff. Over 90 percent of fractures heal this way, without surgery.
Surgical Options
if non-operative care isn't enoughSurgery is needed when there is an open fracture (bone broke through skin), an injury to the artery, a floating elbow (humerus fractured at the same time as a forearm bone), the bone will not stay aligned in a brace, or the fracture is around an existing implant.
Frequently Asked
questions we hear in clinicWill I need surgery?
Most likely not. Most humeral shaft fractures heal in a functional brace, and over 90 percent get better this way without surgery. Surgery is reserved for specific situations: an open fracture (the bone broke through the skin), an injury to the artery, a floating elbow (the humerus and a forearm bone broken at the same time), a fracture that will not stay aligned in the brace, or a fracture around an existing implant.
What is the Sarmiento brace?
It is a custom plastic brace that wraps around the upper arm. You start in an initial splint for a few days to let the swelling settle, then move into the brace. It holds the bone aligned while still letting your elbow and shoulder move, which is what keeps the arm from getting stiff while the fracture heals.
I cannot lift my wrist or fingers. What does that mean?
That is called wrist drop, and it means the radial nerve, which wraps around the back of the upper arm bone, has been stretched or pinched. It happens in roughly 10 to 15 percent of these fractures. It is almost always temporary: the nerve recovers on its own over weeks to months as the fracture heals. Tell your surgeon right away so it can be tracked.
How does this fracture happen?
A humeral shaft fracture is a break in the long middle section of the upper arm bone. It happens from a direct blow, a fall, or a sudden twisting force.
Will I need any scans besides an X-ray?
Front and side X-rays of the humerus confirm the fracture. A CT scan is added only in certain cases: when the fracture is around an existing implant, or when the bone looks abnormal, which can suggest an underlying tumor or weakness.
Providers Who Treat Humeral Shaft Fracture
fracture care team
Further Reading
authoritative sourcesExternal patient-education references and related OSI pages for additional background: