Age matters more than you think when it comes to treatment for shoulder dislocation

The shoulder joint (glenohumeral joint) is the most commonly dislocated joint in the body, according to the National Institutes of Health. It accounts for about 50 percent of all major dislocations seen in U.S. emergency departments.

Shoulder dislocation, also called shoulder instability, is typically a traumatic-type injury where the ball-shaped top of the humerus pops out of the socket in the shoulder blade. It can pop out in three different directions, according to orthopedic surgeon Ralph Cook, IV, MD.

The most common type of dislocation is an anterior dislocation. Those account for about 90 percent of all dislocations. They are extremely painful, and patients will have a significantly reduced range of motion.

The shoulder socket (glenoid) is rather shallow, Dr. Cook explained. It has a cartilage O-ring around it called the labrum, which creates a buffer similar to a chock block to keep the humeral head or ball in place. When an anterior dislocation occurs, the humeral head (top of upper arm bone) goes over the anterior labrum. Oftentimes, the labrum is torn off the glenoid as it dislocates. Sometimes it takes a piece of the bone from the socket glenoid during this process. This is called a bony Bankart lesion, which is basically a fracture of the anterior rim of the socket or glenoid. It can also cause an impaction injury to the posterior humeral head as the shoulder goes back into place, called a Hill-Sachs lesion.

“Patients typically present to the (emergency department) with this type of injury,” Dr. Cook said. “If they are acutely dislocated and typically require a reduction, oftentimes we’ll inject a numbing agent into the joint and then we will pull on the shoulder to put it back into place. Sometimes we give sedation for that as well, just to relax their muscles.”

Age is a Factor

What happens next depends on the patient’s age. If a patient is over the age of 40 or 50, they tend to tear their rotator cuff rather than the labrum. They get an MRI follow-up to assess the rotator cuff to make sure it’s still intact.

It’s a very different situation for younger patients, he said. “In those patients when they tear the labrum, they get that Hill-Sachs lesion and sometimes they chip off a piece of the anterior socket in the glenoid and we call that a Bankart lesion, which is named after the surgeon who initially described it.”

Patients under the age of 20 who have a first-time dislocation have about an 80 to 90 percent chance of recurrence, so surgeons often treat those patients more aggressively. They typically do surgery to fix the labrum.

Patients over the age of 20 (but under the age of 40 – 50) are treated with sling immobilization for a week, he said. They then are prescribed physical therapy for six to 12 weeks, depending on how they are progressing, to work on restoring their range of motion and strength.

“If someone (in that subgroup) has a subsequent instability event, that is, they dislocate at least twice, they will then proceed with surgery, which typically consists of a labrum repair or a Bankart repair,” Dr. Cook said.

But treatment depends on what an MRI shows. The MRI is typically done with contrast to better highlight the labrum. The MRI also shows the degree of bone loss. If there is significant bone loss to the glenoid (shoulder socket) as with bony Bankart lesions, patients benefit from a procedure called Latarjet where a piece of bone from the front of the shoulder blade is transferred to the glenoid socket to reinforce the joint and prevent future dislocations.

Some patients with Hill-Sachs lesions do better with a procedure called remplissage, which is the French word for “to fill,” Dr. Cook said. Basically, the surgeon fills the Hill-Sacks lesion with tissue from the posterior rotator cuff to create a barrier or tether to prevent the humeral head from dislocating.  Patients might lose about five to 10 degrees of motion, but most tolerate this procedure really well.

With the combination of labrum repair and remplissage, surgeons can extend the acceptable limits of bone loss, Dr. Cook said. “And the reason that’s important is because the labrum repair and the remplissage are arthroscopic procedures, performed through minimally invasive poke-hole incisions,” he said.

“The Latarjet procedure is an open-shoulder surgery where we actually cut through the skin and move the muscles around. It’s just a bigger surgery and longer recovery. So, if we can do less and get similar outcomes or better outcomes, we’ve tended towards that in recent years.”

Two Other Types

Posterior shoulder instability is very different from anterior shoulder dislocation. It is usually a gradual deterioration or tearing of the posterior labrum over time. Patients usually feel a dull, achy pain in the posterior of their shoulder. Those patients usually start with physical therapy. If their condition doesn’t improve, an MRI is ordered, to see the extent of the damage.

“Sometimes we consider doing a steroid injection and if these options do not resolve their symptoms, they oftentimes will benefit from a posterior stabilization procedure, which is done exactly the same as the anterior stabilization,” Dr. Cook said. “It’s just on the other side of the socket.”

The third type of shoulder instability is multidirectional instability. This occurs in people who have relaxed ligaments and are able to contort their body in ways most of us can’t. They tend to make great gymnasts because of this, but that flexibility is a double-edged sword because if they don’t maintain strength around the shoulder girdle, the humeral head can slip downwards, backwards or forwards with certain shoulder motions.

That group also includes people who habitually and consciously dislocate their shoulder and put it back into place, such as contortionists.

“It’s not good for your body to be doing that. Every time that shoulder slips out, you risk injuring that bone and the more bone you lose, the less stable your shoulder becomes,” Dr. Cook said.

Those patients are usually prescribed long-term physical therapy of up to a year to strengthen the 17 muscles around the shoulder. If patients don’t improve, they could need a surgical intervention to tighten the capsule around the glenoid socket.

Even if a person does need surgery, orthopedic surgeons have made great strides with regard to pain control postoperatively with regional anesthesia, Dr. Cook said.

“These patients get a nerve block and that block typically last for 24 to 72 hours,” he said. “The vast majority of post-operative pain is in those first 48 to 72 hours after surgeries. We really kind of shield them from that, which is great.”