What are the potential complications of this fracture?
Complications are events or conditions, which make the process of recovering from the fracture more complex. Although most of them are rare, much of the management of the injury is directed at avoiding or reducing the extent of complications. It should be noted, however, that persistent swelling at the fracture site may be felt in the case of collarbone or breastbone fractures and there may be slight asymmetry between the shoulders. This would be considered normal. After acromioclavicular separation there may also be a persistent bump with the outer end of the collarbone riding high. More serious long-term problems that have a major effect on the management of shoulder fractures are listed below.
Stiffness
Injury often causes bleeding into a joint. This blood clots (coagulates) but remains in the joint. Eventually the clot is transformed into scar tissue. If the joint remains immobile while this scar tissue forms, it may adhere to different parts of the joint and bind them together (adhesions). This will result in loss of range of motion (stiffness) of the joint and sometimes pain when the scar is stretched. With three joints involved in a shoulder injury it is not unusual for one or more of them to stiffen up during the recovery process particularly if the shoulder needs to be immobilized for a long period.
Physical Therapy at Physioflow Physical Therapy will help to avoid any stiffness developing in your shoulder. Early pendular exercises, as mentioned above, are particularly important in avoiding stiffness as a complication. At the earlier stage where a blood clot has not yet transformed into an adhesion, the tissue has no strength and can easily be stretched. It is also painless at this stage, as the developing adhesion has no nerve supply so it is the best time to stretch it out. Later on the adhesions can be stretched via Physical Therapy mobilizations but this is slower, can cause some discomfort, and may not be completely successful. Thus, avoiding adhesions and maintaining early motion (as allowed by your doctor and Physical Therapist) is the best form of treatment to avoid shoulder stiffness.
Nerve Injuries
Injuries to the brachial plexus were referred to above. If the injury is complete the prognosis for full recovery is poor as the nerves have a long way to grow before they re-attach to their “targets” in the hand and forearm. Even after surgery to repair the nerves, the outcome cannot be predicted. More often the injury is that of a stretch to the nerve and recovery is slow but complete. If a brachial plexus injury does not fully recover, the treatment depends on the disability and the needs of the patient. Muscle transfer operations to restore the function of the elbow and hand may be needed.
Injury to the axillary nerve, which can occur after shoulder dislocation or an ORIF surgery, usually recovers.
Infection
After an open fracture, there is a small risk (2% or less) that the contamination at the time of the injury will result in a bacterial infection of the surgical site.
If the wound remains swollen, tender and red longer than normal an infection must be suspected. A fever may occur and pus may accumulate in the wound or drain from it. Your doctor and Physical Therapist will closely monitor how your surgical wound is healing to watch for these signs of infection, which require immediate attention. A culture of the pus or blood cultures may isolate the bacteria causing the infection. High doses of antibiotics for an extended period are required if an infection is present.
It is often necessary to repeat surgery to remove contaminated and non-viable tissue, wash out the wound and drain it. Antibiotic beads are often placed in the wound so there is a high local concentration of the drug.
With early aggressive management it is usually possible to suppress or eliminate the infection until the fracture heals. At that point removal of any remaining metal implants usually allows the infection to heal completely with no long-term consequences. Where an infection of bone is incompletely healed, it may be quiescent for some years and flare up later when the patient is stressed.
Recurrent Instability
After dislocation of the glenohumeral joint the ligaments may be pulled off the front of the glenoid and do not re-attach securely. The shoulder is then at risk for repeated dislocations, each of which will further stretch and damage the structures that normally prevent dislocation.
This situation frequently results in surgery to reconstruct or re-attach the ligaments. Recurrent instability may also occur at the acromioclavicular joint and the sternoclavicular joint if they have been injured. Treatment of these problems depends on the individual situation.
Malunion
Malunion means that the fracture heals in an incorrect position. This is frequently asymptomatic; the scapula often unites with fragments overlapping or rotated. However, because the scapula acts primarily as a site of attachment for muscles the new shape does not affect function and is rarely noticeable. The collarbone is just under the skin and any malunion can be felt as a swelling or overlap in the area. In rare cases small pieces of bone (spicules) from an angulated clavicle fracture may work their way through the skin and may need to be trimmed off.
The most detrimental problem with malunion occurs in relation to a joint. If an avulsion fracture of the greater tuberosity heals malunited it may impinge on the acromion process when the arm is lifted to the side. This situation can be treated with surgery to recess the tuberosity back into position and fix it. If the fracture involves the joint surface itself malunion may mean that the joint surface is irregular. This predisposes the joint to early post-traumatic arthritis. If the malunited fracture involves the glenoid it may be possible to operate to move the fragment back into position and make the joint surface smoother. Due to problems with the blood supply this may not be advisable in the case of malunited fractures of the head of the humerus.
Nonunion
When a fracture has failed to heal and will not heal without further intervention it is called a nonunion. This is unusual in all the bones of the shoulder girdle except the collarbone. Even in the collarbone it is rare but can be troublesome with pain and tenderness limiting function of the arm. Treatment involves surgery, bone grafting and fixing the fracture with a plate and screws. This procedure is successful in healing the fracture 90% of the time. Due to the possibility of nonunion and concerns about malunion of the collarbone some surgeons are recommending ORIF for the initial injury in selected patients. When a collarbone has been treated with an ORIF the plate is usually just under the skin. It is uncomfortable, especially with shoulder straps, and it may be necessary to do a second operation to remove the plate. Nonunion in proximal humeral fractures occurs in the context of fixation failure (see below).
Hardware Failure
Metal that is repeatedly stressed will eventually undergo fatigue failure. It is similar to wiggling a wire up and down until it breaks. This occurs also in metal implants used in fracture treatment. The “wiggle” is supplied by micro-movement at the fracture site. It is a race between the bone healing and the metal failing, of which the bone usually wins.
In cases of delayed or non union, cases where the fixation is weak, or cases where the shoulder is loaded early before the bone has healed, the hardware may fail. This is the reason for restrictions on using the shoulder too early. Even though the shoulder may feel painless and strong, if it is still dependent on the metal for its strength, it makes no sense to test that strength.
Hardware failure can sometimes be treated non-operatively by resting and immobilizing the shoulder and expecting healing to progress. Often, however, it requires repeat surgery. The restrictions on activity imposed by your surgeon and Physical Therapist are aimed at avoiding this complication.
Another problem that is specific to the shoulder region is the quality of the bone. Many fractures occur in the elderly with osteoporotic bone. Bone that is osteoporotic does not hold screws well and loss of fixation can occur when screws pull out of the head of the humerus. Modern plate designs with locking screws are aimed to avoid this problem but this is only partially successful. Failure of fixation for any reason makes nonunion or malunion more likely to occur.
Post Traumatic Arthritis
A joint surface will wear out prematurely when a joint has not moved for a long time, if the joint surface was damaged as part of an injury, or where the joint surface is an irregular one. This is called post-traumatic arthritis. The shoulder will become aching and painful to move or load, the range of motion of the joint will become restricted, and the x-rays will show loss of joint surface, spurs, and loose bodies in the joint.
This process takes years but may be a severe functional problem in a younger patient. The symptoms can be treated with pain medication and anti-inflammatory medication (NSAIDs.) Physical Therapy is helpful in retaining range of motion and regaining normal use of the shoulder. In cases with severe pain a shoulder replacement may offer the best outcome.