Fractures of the humeral shaft are fairly common. Elderly patients with weaker bone can break their arm with relatively low levels of force (e.g. a simple fall) , but younger patients tend to require powerful twisting or bending forces to break their humerus.
Most humeral shaft fractures do not require surgery. If you don't require surgery you will be fitted with a humeral brace (a moulded plastic brace) and a sling. This helps to stabilise your broken bone and allows you to move your elbow gently to avoid that getting stiff while your fracture heals. Approximately 90% of well-selected humeral shaft fractures will heal without surgery. It takes approximately 12 weeks for bony healing in most cases.
Some fractures will benefit from early fixation.
- Open fractures (where your bone comes out of the skin) need urgent surgery to washout any contamination, fix the fracture and minimise infection risk.
- Transverse fractures carry a higher risk of non union if left alone, so in Mr Granville-Chapman's hands, these are normally fixed.
- Displaced fractures that lie near the elbow will normally heal, but deformity may be hard to tolerate and elbow stiffness is a problem. Again, Mr Granville-Chapman will normally offer surgery to fix these injuries.
- Some fractures are hard to control with a brace because of their location near the armpit. If an acceptable position cannot be maintained in a brace, you may require surgical fixation.
The first couple of weeks will be the most sore; thereafter your pain and swelling should begin to subside. Initially you will want your sling and brace. You will be shown very simple gentle exercises for your arm that will keep your shoulder and elbow supple. As your fracture begins to heal, your arm will feel more solid and you will probably be happy to wean off your sling. Please maintain your brace until asked to remove it.
You will not be ready to drive for eight weeks or more and you will need to be off work for at least two weeks for a desk-based job. Manual work will take at least three months.
The radial nerve is one of the three main nerves that supplies your forearm and hand. It wraps closely around the back of your humerus in its mid-shaft as it travels from your armpit to your forearm. This nerve supplies the muscles that extend (lift up) your wrist and fingers. It also supplies the skin's sensation over most of the back of your hand.
A radial nerve injury is present in 11% of humeral shaft fractures, with certain fracture patterns having carrying an even higher risk of injury. The injury happens as the nerve, which is tethered by some tough fibrous tissue a few centimetres lower down your arm, gets stretched by the fracture displacement, or directly injured by sharp fracture fragments. The nerve can also get caught in the fracture site and squashed.
Often patients will report pins and needles, or frank numbness over the back of their hand and a dropped wrist.
Thankfully the nerve is normally bruised and stretched and not cut. While this bruising and stretching can stop the nerve from working, over 90% of these injuries will recover. It is generally therefore accepted that a radial nerve injury with a humeral shaft fracture is not on its own a reason to operate. However, this recovery can take a long time as regeneration of the damaged nerve fibres inside the nerve occurs slowly (1mm a day). It may therefore be several months before all your muscles regain power. If your nerve is injured, and you require surgery for your fracture (e.g. the fracture displacement or pattern warrants an operation), then your nerve will be explored to confirm it's intact and free from entrapment.
Until your motor recovery, you will benefit from a wrist splint to keep your hand and wrist in a functional position and you will be given exercises to keep your joints supple. Your surgeon will follow your recovery closely. If there is no sign of nerve recovery, you will be sent for nerve testing. This will give a good idea of the state of the nerve and it is often helpful in terms of prognosis. Very rarely, the nerve will need to be surgically explored, freed of scar tissue and even more rarely grafted at a later date. If your nerve is not recovering you may also require tendon transfer surgery to restore wrist and finger function to your hand.