What treatments should I consider?
This fracture can often be treated in a cast. The most common type of cast used is the hanging cast. This cast is applied with the elbow bent at a right angle. The cast goes from above the elbow to the knuckles and prevents movement of the elbow, forearm and wrist, leaving the fingers and thumb free to wiggle. The cast is suspended from the neck to a ring attached to the forearm part of the cast. This point of suspension is chosen so that the upper arm hangs straight when the patient is sitting or standing. The cast does not immobilize the fracture but uses the traction from the weight of the hanging cast to position the arm so that the fracture is straight.
During the first few weeks of treatment the you can usually feel some movement at the fracture site, particularly when you lie down and the bone tends to bend. As healing progresses and the tissue at the fracture site gets stronger this sensation of movement goes away. Once the fracture has reached this stage of healing, the cast can be removed. Many surgeons use a removable brace on the upper arm at this stage and continue protection in a sling.
X-rays are taken frequently during the early part of treatment to make sure that the fracture position is acceptable. By six weeks one usually sees new bone formation at the fracture site, bridging across from one fragment to the next. This bridging callus is not as strong as normal bone but is a good sign that the bone is healing. By three months post injury the healing bone tissue is about 80% as strong as it needs to be. By this stage the cast or splint can be discontinued and the patient can begin work on recovering range of motion of the shoulder and elbow. Return to heavier work or sports activity is less predictable and will depend on the surgeon's assessment of the strength of the healing bone. There is known to be some improvement in the strength of healing bone for as long as 18 months post injury.
This non-operative method of treating a fracture of the humeral shaft does not usually make the bone completely straight. Because of the excellent range of motion at the shoulder, a degree of angulation at the fracture site does not affect the function of the arm and can be accepted. A small amount of angulation is also cosmetically acceptable because it is hidden by the muscles of the arm.
Some situations and some fracture patterns require surgery. Any open fracture needs an operation to wash out all dirty material and remove any dead tissue. It is controversial whether open fractures should be fixed. Some surgeons fix the fracture because they believe that infection is less likely and less damaging if the fracture is held still. Other surgeons do the debridement surgery to clean up the wound but treat the patient in a cast after that, because they believe that minimal interference with the blood supply of an open fracture is better. External fixation with a frame and pins may be used in some open fractures after the debridement surgery.
Another strong indication for surgery is the presence of multiple injuries. If the patient has been in an accident with fractures to the legs or the other arm it may be better to fix the fractured humerus so that the arm can be moved as one. It is very awkward to nurse a patient with a cast on the arm and a broken leg. Using crutches may be difficult until the fractured arm is strong enough. This stage is reached more quickly with surgical fixation.
The third major reason of undertaking surgery to fix a fractured humerus is when the result from non-operative treatment would be un-acceptable in the judgement of the surgeon or after discussion with the patient. Fracture patterns which would result in unacceptable malunion or have a very high risk of nonunion would come into this category. The patient may prefer to have surgery in order to speed up recovery.
There are three types of surgery used to fix fractures of the humerus:
- Internal fixation with a plate and screws
- Internal fixation with an intramedullary rod
- External fixation
Internal fixation with a plate and screws
The operation with plate and screws requires opening up the fracture, exposing the bone and putting the fragments together then holding them in place with screws from a metal plate going into the bone. This system affords rigid secure fixation and can also compress the bone fragments together. This aids healing. Exposure of the fracture site makes it possible to reduce the fragments exactly but it does disturb the blood supply of the fracture site. Bone graft can be placed in the fracture site to help healing if considered necessary.
Removal of the implant (plate and screws) may be considered after the fracture has healed and consolidated especially if the site is tender or aching. This operation requires a repeat of the exposure of the site but recovery is much quicker as the bone does not need major healing.
Internal fixation with an intramedullary rod
With intramedullary fixation (IM rod) of the humerus the fracture is reduced indirectly by manipulation without opening it up. A small exposure is made at the shoulder and a metal rod is inserted into the bone at the shoulder, passed down inside the bone and across the fracture into the lower fragment. This lines up the bone fragments correctly. The bone is held securely by screws passed through the bone and into the rod at both ends.
The main advantage of this method of fixation is that the fracture site is not disturbed so the blood supply of the bone fragments may survive better. It is also very strong mechanically. Technically it is a difficult operation requiring special instruments and an X-ray system to view the fracture during the surgery. The top end of the rod may be irritating and make shoulder movement painful. It is almost always necessary to remove the rod once the fracture has healed. Removal of the rod is a relatively minor operation which does require an anesthetic but is usually done as a day surgery procedure.
With external fixation, strong metal pins are inserted into the bone fragments above and below the fracture. The pins are firmly attached to a frame that spans across the fracture. This holds the fragments immobile while the bone heals. The arm itself can move while in the frame so hand and elbow function does not deteriorate. Because the alignment of the fracture can be adjusted after the frame has been applied this technique is often used for the more complicated fractures and ones in which there is bone loss. The disadvantage is a higher incidence of infection where the pins go through the skin. If this technique is used the pins and the frame are removed as soon as the bone has healed sufficiently. This procedure does not usually require an anesthetic. The fracture may need to be protected in a brace for a period after removal of the frame.