Fracture of the humerus, the long bone of the upper arm connecting the arm to the shoulder, is a serious injury. Fractures of the long bone are divided into three types depending on where the fracture occurs. If the break is in the upper portion of the bone of the arm, the fracture is called a proximal humeral fracture. If the fracture is at the end portion of the bone, the fracture is termed a distal humeral fracture, while it is known as a diaphyseal fracture if the break occurs in the middle portion of the bone shaft.
Although fractures of the humerus can be caused in many ways, the most common cause is traumatic injury during sports and accidents, including car accidents. The humerus may also fracture when the bone tissue has become weakened by osteoporosis or cancer, or in the case of infection or other metabolic conditions. These bone fractures are known as pathological fractures.
Proximal humeral fracture
Proximal humeral fractures occur in the proximal portion of the humerus close to the shoulder joint. They may also be accompanied by damage to the tendons of the rotator cuff and/or the surface of the glenohumeral joint.
Diaphyseal humeral fracture
These are fractures occurring on the bone shaft between the shoulder and elbow. Most diaphyseal fractures will heal without the need for surgery, although the decision regarding surgery or conservative treatment will depend on the type of fracture.
Pre-operative planning requires careful patient assessment since important structures like arteries, veins and nerves all run alongside this portion of the arm bone.
Distal humeral fracture
Distal fractures of the humerus, i.e., a fracture near the elbow joint, occur less frequently. The result of high-energy blunt force trauma causing misalignment of the bone, distal humeral fractures often require surgical repair of the joint surfaces.
Most humeral fractures heal without the need for surgery, just by placing the arm in an immobilizing brace for 3/4 weeks. Thus immobilized, the broken bone will heal spontaneously. Care must be taken to ensure that the humerus is correctly aligned with the joint in its anatomical position.
Surgical treatment of a fractured shoulder
As already mentioned, surgery of the humerus may be necessary when the fragments of splintered bone have been displaced from their natural position, resulting in what is known as a “displaced” fracture. Ensuring if the alignment of the bone fragments is acceptable depends on several factors. Fractures near the shoulder or elbow joint, especially if the fracture extends into the joint itself, are most likely to require surgery since realignment and reconstruction must be perfect, otherwise once healed, the fractured joint may have limited functional ability, which in time may lead to arthrosis.
The type of surgical fixation procedure for a humeral fracture will depend on the type of fracture sustained.
The degree of severity of a displaced fracture, the number of bony fragments and their size will guide the decision as to whether to choose fixation with angular stable plates and screws, including, if necessary, bone grafts to sustain the fracture. Should the fixation procedure using angular stable plates and screws not be possible, the injured joint will be removed and replaced with a prosthesis.
The procedure is carried out with open surgery. A small incision is made in the skin to allow the surgeon direct vision of the surgical field, thereby avoiding the vessels and nerves and allowing accurate reduction, or “reconstruction of the puzzle” of bone fragments, which are then secured in place (synthesis).
Should the fracture be displaced and comminuted (with many small bone fragments) making simple reduction impossible, the surgeon may opt for a specific prosthetic implant to replace the badly damaged joint.