A recent review of the literature found that immobilization followed by physical therapy remains the standard treatment following shoulder dislocation in young children. The review did find a paucity of evidence regarding the appropriate treatment, possibly due to the fact that shoulder dislocation in the younger population is rare with about 20 per cent of all dislocations occurring in the less than 20 year old population and .92 per vent of those occurring in less than nine year olds.
Your upper arm bone, known as the humerus, continues to form after birth. The end of the bone that makes up part of your shoulder joint has two bone-forming centers called ossification centers. One of these centers stops laying down bone when a child is between five and seven years old and the other stops between 14 and 17 years old. This is significant because if these centers are disrupted prior to them finishing their job trouble can result. Once these centers, along with others located in other parts of the skeleton are closed, a person is considered “skeletally mature.”
The shoulder joint relies heavily on a joint capsule, shoulder rotator cuff muscles and ligaments to hold it together. The combining motion of these structures allow for us to have a great range of motion at our shoulder joint. If any of these structures fail, due to trauma or laxity, the shoulder joint can dislocate. A true dislocation involves the humeral head slipping outside of the capsule and it requires someone to “reduce” it or put it back in place. Sometimes the humeral slips out of the capsule slightly, or jumps its normal track, and this is called a subluxation. A subluxation does not normally require a reduction and the person can usually move their arm around to get it “back into place.” The direction of the location is also important to note, with the most common being the humeral head slipping out towards the front of the armpit.
In a child, tissues tend to be more elastic which can be more forgiving during an injury. If an injury does occur, it is typically a fracture as children’s ligaments are often stronger than their bones. The anatomical shoulder capsular attachment site also adds for more stability than in an adult. These factors make shoulder dislocation difficult to happen in children and less likely to re-occur once it does happen. That being said, however, when a traumatic dislocation does happen part of the front of the capsule can tear, called a Bankart lesion.
The evidence is very inconsistent regarding redislocation rates for skeletally immature children, with studies siting anywhere from 0-100 per cent. One study delved further into the dislocation recurrence rate and looked at the differences in age when the dislocation occurred. They found that the younger the child was at the time of dislocation, the less likely they were to re-dislocate in the future and that they had less actual damage to their capsule, which was probably due to the elasticity of their tissues.
Following reduction, patients are put in a sling to allow for the stretched joint structures to rest. The length of time in the sling is still debated, but often ranges from one to six weeks. This length of time has not been investigated in relation to re-dislocation rates. The direction that the arm is held in the sling is also controversial, the most common direction being palm towards the stomach with the elbow away from the side of the trunk. However, a recent study found better results for dislocations that happen to the front to be placed in a sling in the opposite direction, or external rotation.
Physical therapy is the gold standard treatment following the immobilization period and includes strength progression. A study following shoulder dislocation treatments in children less than 16 years old found that physical therapy was effective for six per cent of first time dislocations, with the remainder requiring surgical intervention.
Surgery is considered when more conservative treatments fail to prevent future instability incidences. Any tears in the tissue are repaired and the surgery is the same as repairs in the adult population. Outcomes of these repairs are excellent in the two studies cited in this article, however the studies conducted were only on a small sampling of patients.
Central to the debate of preventing recurrent shoulder instability in the non-skeletally mature patient is to have surgery or not. Results are favorable for preventing recurrent dislocations for adult patients, but are mixed with the younger populations. Immobilization followed by physical therapy remains the gold standard treatment in populations less than 14 years old without a Bankart lesion who have only dislocated one time. Surgery becomes an option with recurring incidences of instability or with a coinciding Bankart lesion.