Written By: Chloe Wilson BSc (Hons) Physiotherapy
Reviewed By: SPE Medical Review Board
A humerus fracture is the medical term for a break in the bone of the upper arm. The humerus is the long bone that sits between the shoulder and the elbow.
Humeral fractures can be classified into three types, depending on which part of the bone is broken:
Fractures in the long, middle section of the upper arm – mid-shaft humeral fractures, are also known as "humeral shaft fractures" or "diaphyseal humerus fractures".
Approximately 3-5% of all broken bones are midshaft humeral fractures. They tend to affect young males (20-30’s) who have experienced a high-energy injury and elderly females (60-70’s) with low-energy injuries.
Here we will look at the common causes of midshaft humerus fractures, the different types and how they are classified, classic symptoms, how they are diagnosed, the different treatment options both surgical and non-surgical, the recovery process and possible complications.
You can find out more about the other types in the shoulder fracture section.
The shaft of humerus can be divided into thirds, the proximal (upper third), middle (mid third) and distal (lower third).
The mid-shaft region of the humerus is the long, thin part of the bone. The top part is cylindrical in shape and as it runs down towards the elbow it becomes narrower and more prism shaped. The back surface of the shaft of humerus is larger than the front.
Common causes of mid-shaft humerus fractures include:
Midshaft humeral fractures can be classified into different types by:
Humerus fractures can be classified by where the break is in the bone:
Humerus fractures can also be classified by the direction of the break in the bone:
A displaced humerus fracture is where the bone fragments of the shaft do not line up normally. A non-displaced fracture is where normal alignment is maintained despite the fracture line.
Humerus fractures are also classified by where the broken bone is visible:
Pathological humerus fractures are where the bone has broken due to a disease that has weakened the bone such as metastases. With pathological fractures, there may not have been a specific incident that caused the injury, the mid-shaft humerus fracture may have occurred spontaneously.
The most common symptoms associated with a mid-shaft humerus fracture are:
If you doctor suspects a mid-shaft humerus fracture you will be sent for shoulder and arm x-rays. X-rays will be taken in different directions, usually from front to back (AP) and from the side (lateral). Both the shoulder and elbow joints should be evaluated for any damage.
X-rays help the doctor to see where the fracture is, what type of humerus fracture it is, any associated damage and the severity of the injury so that they can plan the best course of treatment.
Treatment for humerus fractures will vary slightly depending on the location and severity of the fracture, but in most cases, surgery is not required. Approximately 90% of humeral shaft fractures unite (heal) without the need for surgery.
Mid-shaft humerus fractures may be treated with:
For the first few weeks after a humerus fracture, a sling or splint is worn to hold the fracture still and to allow the swelling and pain to subside. The fracture needs to be immobilised to allow time for the bones to knit back together and heal.
Humeral shaft fractures are normally treated with a "coaptation splint" that extends from the shoulder to the forearm, holding the elbow in 90 degrees flexion.
You may be given a collar and cuff sling to support the arm. It is really important to let the arm hang by your side without any support through the elbow as this allows gravity to help realign the fracture. If there is any pressure through the elbow it pushes the bones together resulting in them healing in the wrong position.
After two to three weeks the coaptation splint is switched for a functional Sarmiento Brace, a cylindrical brace that fits around the upper arm holding the humerus in place. It leaves the shoulder and elbow free to move which helps prevent stiffness.
Medication to relieve pain and inflammation will be prescribed following a humerus fracture. If it was an open fracture you will also be given antibiotics to help reduce the risk of infection.
A physical therapist will work through a rehabilitation programme with you following a midshaft humeral fracture. Exercises for the elbow, wrist and hand should be started as soon as possible to prevent stiffness and weakness from developing and it is usually fine to take your arm out of your sling to do these.
Rehab exercises following humerus fractures consist of:
It is important to stick with the rehab programme and to do your exercises every day until you have regained full strength, flexibility and movement at the shoulder, elbow and hand. If you stop too soon, or only do your exercises sporadically you are likely to have ongoing limitations in the mobility, strength and function of your arm.
Around 10% of humeral shaft fractures will require surgical treatment. If the bone fragments are displaced, then the fragments will need to be realigned and held in place. This process is known as an Open Reduction Internal Fixation (ORIF). Usually the humerus fracture is secured with either:
Humeral shaft fractures that require surgery are usually treated with a large metal plate held in place by screws.
Pros: Highest success rate for surgical treatment of humerus fractures
Cons: Higher risk of nerve damage and non-union than non-surgical treatment
In some cases a humerus fracture will treated surgically with an intramedullary rod/nail. This is when a long metal rod is placed down the middle of the bone. IM nails can be used to stabilise a humerus fracture that is between 2cm below the surgical neck and 3 cm above the elbow.
Pros: Less invasive and less chance of nerve damage.
Cons: Lower healing rate and higher rate of non-union
Metalware is designed to hold the bones together while they heal – full union should still be achieved. Metal implants are not meant to be a long term solution and if the bones fail to unite, then there is a high chance that the metalware will at some point fail and further surgery may be required
The usual indications for treating a mid-shaft humerus fracture surgically are:
Over 90% of humerus fractures treated non-operatively will unite and are usually fully healed (complete union) within 8-12 weeks. Older patients may not regain full shoulder movement, but they usually regain enough functional range for their day to day activities.
Complications are more common with complex fractures and those requiring surgery.
Mid-shaft fractures may heal with slight angulation i.e. not completely straight, but this doesn’t usually cause any functional issues as the shoulder and elbow accommodate.
There are a number of common complications with mid-shaft humeral fractures:
The best way to ensure you make a full recovery from a midshaft humeral fracture, whether it is treated surgically or not, is to follow your exercise rehab programme.
Starting exercises as soon as you can tolerate them and continuing them regularly, at least twice a day, over the next few months is the best way to regain full strength, flexibility and mobility. It can get frustrating but do persevere.
You will find a whole range of suitable exercises in the shoulder exercises section including progressive plans for mobility exercises and strengthening exercises for after humerus fractures.
You can also find out more about the different types of shoulder fractures, how the present and how to treat them in the shoulder fractures overview. If you injury is at the top part of the upper arm, visit the proximal humerus fracture section.
There are lots of other possible causes of shoulder pain. If a humerus fracture isn't sounding like your problem, check out the shoulder pain diagnosis guide.
Page Last Updated: 17/05/2022
Next Review Due: 17/05/2024
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