Arthroscopic Stabilization for Shoulder Instability
The shoulder is a ball-and-socket joint that is made up of three bones: the scapula (shoulder blade), the humerus (upper arm bone), and the clavicle (collarbone). When the structures around the joint are not keeping the ball tightly within its socket, the shoulder is considered unstable. Subluxation refers to a loose joint that has partially slipped out of place. Dislocation refers to a loose joint that has fully slipped out of place. If left untreated, shoulder instability can lead to arthritis of the shoulder joint.
Causes
There are three common ways in which a shoulder can become unstable:
Shoulder Dislocation
Shoulder instability often follows an injury that caused the shoulder to dislocate. This initial injury is usually fairly significant, and the shoulder must be reduced (put it back in the socket). The shoulder may seem to return to normal, but the joint often remains unstable. The ligaments that hold the shoulder in the socket, along with the labrum (the cartilage rim around the glenoid), may have become stretched or torn. This makes them too loose to keep the shoulder in the socket when it moves in certain positions. An unstable shoulder can result in repeated episodes of dislocation, even during normal activities.
Repetitive Shoulder Strain
In some cases, shoulder instability can happen without a previous dislocation. People who do repeated shoulder motions may gradually stretch out the joint capsule. This is especially common in athletes such as baseball pitchers, volleyball players, and swimmers. If the joint capsule gets stretched out and the shoulder muscles become weak, the ball of the humerus begins to slip around too much within the shoulder. Eventually, this can cause irritation and pain in the shoulder.
Multidirectional Instability
In very few patients a genetic problem with the connective tissues of the body can lead to ligaments that are too elastic (stretch too far). When ligaments stretch too easily, they may not be able to hold the joints in place. All the joints of the body may be too loose. Some joints, such as the shoulder, can easily be dislocated, moving out the front, out the back, or out the bottom of the shoulder. This is called multidirectional instability. People with this condition are sometimes referred to as double-jointed.
Symptoms
Shoulder instability causes several symptoms, which may include:
- Repeated dislocations (partial or complete)
- Persistent sensation of the shoulder feeling loose
- Pain, often described as a pinching in the shoulder
- Numbness on the outside of the arm (caused by stretched nerves)
Diagnosis
In order to properly diagnose shoulder instability, it is best to see an orthopedic specialist who will assess your medical history and perform a thorough physical examination of your shoulder. In addition to diagnosing the condition, an orthopedic specialist can plan the best nonsurgical or surgical treatment options for you.
In the physical exam, your doctor will feel and move your shoulder, checking it for strength and mobility. Your doctor will also stress the shoulder to test the ligaments. Imaging tests, such as X-ray, may also be ordered to confirm that the shoulder was dislocated or injured in the past.
If further examination is needed to make a diagnosis, the shoulder may need to be examined with an arthroscope. An arthroscope is a tiny TV camera inserted into the shoulder through a small incision. It allows the surgeon to get a clear look at the muscles of the shoulder. In order to keep the muscles relaxed, the patient will be put to sleep with general anesthesia.
Treatment of an Unstable Shoulder
Nonsurgical Treatment
Your doctor’s first goal will be to help you control shoulder pain and inflammation nonsurgically. Nonsurgical treatment typically includes:
- Anti-inflammatory medication, such as aspirin or ibuprofen. In some cases, a cortisone injection may be recommended. Cortisone is a strong anti-inflammatory medication.
- Reducing or avoiding activities that may aggravate your shoulder.
- Physical therapy to strengthen and increase stability.
Surgery
If your therapy program doesn't stabilize your shoulder after a period of time, you may need surgery.
Surgery on the shoulder has improved dramatically over the past two decades. The most common method for surgically stabilizing a shoulder is called the Bankart repair. In the past, this procedure was done through a large incision in the front (anterior) shoulder joint. Today, however, arthroscopic surgery can be used to repair and stabilize shoulders after they dislocate. Arthroscopic procedures are minimally-invasive, often allowing patients to return home the same day as surgery.
Another surgery to tighten a loose shoulder joint is a procedure called a capsular shift. The lining of any joint is called the joint capsule. The joint capsule forms a pocket, or bag that is made up of the ligaments and connective tissue around the joint. The shoulder joint has a fairly large joint capsule that is necessary to allow the joint to move in such a wide range.
Sometimes the problem causing the shoulder instability is caused by the joint capsule simply being too large. This is sometimes referred to as a redundant, or patulous joint capsule. In order to fix this type of instability, the joint capsule needs to be made smaller and tightened surgically.
Rehabilitation After Shoulder Surgery
After surgery, your orthopedic care team, including our physical therapists, will set goals to get you on the road to recovery. You will likely wear a sling to support and protect the shoulder for one to four weeks. Depending on the surgical procedure, you will probably need to attend therapy sessions for two to four months. You should expect full recovery to take up to six months.
To speak with an SROSM shoulder specialist, make an appointment at the location closest to you in Spring or The Woodlands. You can also learn more about arthroscopic stabilization for shoulder instability by downloading our education document A Patient’s Guide to Shoulder Instability.