Richard Cunningham, MD, of Vail-Summit Orthopaedics & Neurosurgery, is a board-certified orthopedic surgeon and sports medicine specialist. He has a clinical focus on conditions of the shoulder including shoulder dislocations. Patients with shoulder instability, particularly recurrent dislocations, often require surgical treatment. This surgery often consists of an arthroscopic Bankart repair with or without a remplissage procedure.

A highly-qualified shoulder specialist, who is trusted for his expertise in treating shoulder dislocations and instability, Dr. Cunningham specializes in shoulder instability surgery. He often treats more complicated cases. Dr. Cunningham utilizes the latest minimally invasive and arthroscopic techniques and implants so that his patients get the best possible outcomes.

Causes of Shoulder Instability and Shoulder Dislocations

In order for the shoulder to have such an extensive range of motion, the shoulder joint needs to be less constrained thus making it a more inherently unstable joint. By comparison, our hip joint has a deep bony socket and this affords greater joint stability but at the cost of less range of motion. The shoulder socket, or glenoid, is a very shallow socket. The relatively vertical and elongated cavity of the glenoid articulates with the spherical head of the humerus (arm) bone. The humeral head is held in the glenoid less by a deep bone socket and more by the following stabilizing structures:

• Glenoid labrum (this is like a rubber gasket surrounding the glenoid socket)
• Joint capsule (a canvas like sac of tissue that contains the ball and socket)
• Glenohumeral ligaments (individual thickenings of the joint capsule that connect the ball to the socket)
• Rotator cuff (4 muscle tendon units that power our shoulder and compress the ball in the socket).

The glenohumeral joint is more vulnerable to injury given its inherent instability. When someone falls on an outstretched arm while snowboarding or biking, they may dislocate their shoulder. In a younger person, a shoulder dislocation typically results in tearing the glenoid labrum off of the edge of the glenoid socket as well as tearing and stretching the capsule and the glenohumeral ligaments. Alternatively, in an older person, a shoulder dislocation typically results in less severe tearing of the labrum and ligaments but is more often associated with tearing of one or more rotator cuff tendons. Finally, some hard falls result in a fracture of the ball or the socket. There are a number of factors that influence what sort of injury one sustains. These factors include the patient’s age, a history of prior shoulder injuries, the amount of laxity of the ligaments, the amount of energy dissipated across the shoulder, and how the energy was directed.

Most glenohumeral dislocations are anterior. In other words, the ball or humeral head dislocates off the front of the socket. Posterior glenohumeral dislocations are much less common. Partial dislocations are called subluxations. In a subluxation, the humeral heard only comes part way out of the socket but not fully out of the socket. When someone has a hard fall and a first-time shoulder dislocation, the person experiences severe pain and a fullness in the front of the shoulder. Patients immediately know that their shoulder joint is out of place. The shoulder may spontaneously reduce itself or go back into socket. In other cases, patients may move their arm in such a way that the shoulder finally goes back into socket. Unfortunately, most patients have to go to the ER to have their shoulder reduced. Patients immediately have much less pain when their shoulder is reduced.

Treatment for Shoulder Instability

Following a shoulder dislocation and when being seen in his office, Dr. Cunningham takes a thorough history to better understand what sort of injury caused the dislocation, what direction was the dislocation, and whether this was the first time. He will obtain x-rays to be sure that there is not an associated fracture. He does a physical exam to confirm that the shoulder is now reduced. He would also assess one’s rotator cuff strength to determine if there could be an associated rotator cuff tear. He would gently test the integrity of the shoulder ligaments to see how compromised they are by doing tests such as a load and shift test, relocation, and apprehension test.  Following a first-time shoulder dislocation, he typically recommends non-surgical management consisting of a short period of wearing a shoulder sling, rest, ice, pain medication if needed, and physical therapy.

If a patient has had recurrent shoulder dislocations (ie. 3 or more), then shoulder stabilization surgery is often indicated. The risk of not doing surgery is that it becomes easier and easier to dislocate one’s shoulder such that patients no longer trust that they can do much with their shoulder. Furthermore, with each additional dislocation, they are doing further damage to their shoulder with injury to the cartilage causing arthritis, wearing away the bone on the edge of the socket each time the shoulder comes out of place, and further ligament tearing. If the patient and Dr. Cunningham choose to proceed with surgery, an MRI would be obtained to assess the degree of labral tearing and to see if there are any other associated tears to the rotator cuff, biceps, or cartilage. If there is evidence of an associated fracture of the rim of the glenoid socket, a CT scan may be ordered to assess the size of the bony rim fracture as this may change the type of surgery required. This comprehensive evaluation informs Dr. Cunningham’s recommendations for surgical treatment.

• Arthroscopic Bankart Repair – Most anterior glenohumeral dislocations result in a typical tearing of the labrum off of the anterior and inferior portion of the glenoid socket. An arthroscopic Bankart repair is a procedure whereby a small camera the size of a pencil is put into the shoulder joint and then small pencil sized instruments are used to reattch the labrum back to its native position on the glenoid. This is done by placing small bone anchors (with new anchors made entirely of soft stitch material instead of metal or plastic) into the edge of the socket bone, passing the stitch around the torn labrum, and then tightening the stitch so that the labrum is brought back to its native position on the edge of the socket where it will heal with time.
• Arthroscopic Remplissage Procedure – When an anterior glenohumeral joint dislocation occurs, the ball comes forward forcefully out of the front of the socket. The labrum and ligaments in the front of the shoulder tear. However, there is also always a component of a bone injury called a Hill Sachs defect. This is an indentation or impaction fracture to the back of the humeral head. This occurs because the bone of the ball is much softer and weaker than the bone of the socket which is much denser and stronger. When the ball comes out of the front of the shoulder, it violently strikes the front edge of the socket, and the socket usually wins this collision thus resulting in an indentation or impaction fracture in the back of the ball. This is called a Hill Sachs defect. The bigger and deeper that this impaction fracture is, the more it predisposes to future shoulder dislocations. As a result, a shoulder surgeon utilizes a surgical technique called a remplissage to minimize the effects of this Hill Sachs fracture. Remplissage is a French term meaning “filling the defect.” In a remplissage procedure, an adjacent rotator cuff tendon (the infraspinatus) is arthroscopically sutured down into the Hills Sachs bone defect thus filling the bony impaction fracture with this tendon. Adding a remplissage procedure to a Bankart repair results in a significantly lower risk of further dislocations.

Arthroscopic Bankart repair may be done alone if there is not a large Hill Sachs defect. However, Dr. Cunningham adds a remplissage procedure to most of his Bankart repairs in order to reduce the chances of the patient ever having another dislocation. This combination of procedures has demonstrated favorable results in Dr. Cunningham’s patients, allowing them to regain full shoulder range of motion and function and getting them back to participating fully in the activities they love.

Dr. Cunningham provides the highest quality and best care for patients with shoulder dislocations and instability. Request a consultation today.