Shoulder Instability and Dislocations

Shoulder Instability GraphicShoulder instability is classified into two categories: subluxations and dislocations. To understand each, we must first understand the shoulder anatomy. The shoulder is a ball-and-socket joint comprised of the humerus (ball) and glenoid or glenoid fossa (socket). The glenoid is a shallow groove which comes off the scapula (shoulder blade) that articulates with the head of the humerus. Due to the glenoid’s shallow groove, the head of the humerus can become dislocated due to a direct force or if the shoulder is severely unstable, the shoulder can dislocate on its own.  An unstable shoulder can slip in and out of the joint, which is referred to as a subluxation. When a subluxation occurs, the shoulder is partially or not completely dislocated. Subluxations typically self-reduce, or return to their original position articulating with the glenoid, spontaneously. It is called a dislocation when the head of the humerus is not reduced and stays out of place. Depending on whether or not it pops back in is how the condition is diagnosed. When either of these injuries are diagnosed, the condition that results is shoulder instability.

Shoulder Instability Graphic 2To briefly review each condition:

  • A subluxation is a partial or incomplete dislocation. If the shoulder is partially out of the shoulder socket, it may completely dislocate. Subluxations typically reduce on their own.
  • A dislocation is when the head of the humerus comes complete out of the glenoid. For some patients, their shoulder remains unstable or continues to dislocate long after the original injury. These patients have chronic instability.

Typically with shoulder dislocations, the labrum is often torn. The labrum is the cartilage the lines the glenoid. This lining tissue helps give depth to the shallow glenoid fossa so the larger humeral head can articulate appropriately. The labrum also serves as an attachment point ligaments of the shoulder. To help visualize the shoulder, picture a golf ball sitting on a tee. The golf ball is the humeral head and the tee is the glenoid socket. On the tee, there are sharp triangular-shaped edges that help hold the ball steady – these little triangular edges are analogous to the labrum. If the labrum becomes torn, dislocations can become more frequent predisposing a patient to chronic instability. Additionally, if the surrounding muscles are weak, this too can play a role in chronic instability. Weakness and multiple dislocations may cause pain and increased instability even with seemingly easy movements such are lifting your arm into an overhead position.

What causes shoulder instability?

Shoulder instability can occur in a number of different ways. Injuries may be caused by:

  • A strong force applied to the shoulder.
  • Extreme rotation.
  • A hit during contact sport.
  • A car accident
  • Falling, such as on an out-stretched arm.
  • A combination or multiple episodes of any of these mechanisms of injury.


Patients may experience a feeling of general instability. When put into certain positions, there may be apprehension or the fear of another dislocation. Some may feel an inability to move the shoulder, intense pain, numbness that radiates down the arm, weakness, and/or swelling. In some cases, there may be an obvious visual deformity or asymmetric appearance to the opposite shoulder.

Dr. Ahmad’s Shoulder Examination

Patient History and Physical Examination
An examination is comprised of a few different components: a history, observation, palpation, special tests, imaging and assessment. At your initial evaluation, Dr. Ahmad and his team will ask you pertinent questions about your injury or how your shoulder became unstable. Once a thorough history is obtained, Dr. Ahmad performs a physical examination that is a combination of observation, palpation, and special testing. During this part of your exam, Dr. Ahmad compares the injured shoulder to the healthy side and will check all the structures of your injured shoulder while locating important landmarks and checking range of motion. Special testing is a key part of the diagnosis process. The tests Dr. Ahmad performs help our team establish a diagnosis and determine which treatment route will give our patient a most favorable outcome.  In addition to a clinical work-up, imaging may be necessary to determine the extent of the injury. Imaging generally includes x-rays and/or an MRI. In extreme cases, a CT scan may be necessary to help our patients.

Shoulder Instability Treatment Options

Treatment for shoulder instability is determined on a case by case basis. While no two patients are the exact same, their treatment should also be as such. Treatment may include immobilization, medication (oral or injections), rehabilitation or surgery.

If you have had repeated dislocations, surgery may be required. However, surgery may be necessary even after a single episode depending on the extent of the injury. Dr. Ahmad performs shoulder instability repairs (labrum repairs) in the arthroscopic setting. Arthroscopy is where small incisions are made in the shoulder so that a camera and other instruments can be passed into the joint to repair the damaged tissues. After surgery, a sling is needed for roughly 4 to 6 weeks and physical therapy will start at your first appointment post-operatively. The first appointment is anywhere from 7 to 14 days after surgery.

Rehabilitation Following Surgery

After surgery, a sling is needed for roughly 4 to 6 weeks and physical therapy starts after your first post-operative appointment. During initial phase, our patients should be in their sling a majority of the time. There are a few instances that a patient may remove the sling such as physical therapy, showering, or when they are in a controlled environment such as relaxing on the couch. Unfortunately, it is required that our patients sleep in their sling in the immediate weeks following surgery as to not disrupt the newly-repaired tissues.

Rehabilitation plays a vital role in getting you back to what you enjoy. The main goals of therapy are to regain motion and increase strength. Dr. Ahmad and our team have created an extensive rehabilitation program for you to follow in the rehab process. Therapy is typically two to three times a week for 4 months and in some cases, longer.

Timelines for Athletes Following Surgery

  • For throwing athletes, if the surgery is to your throwing shoulder, it is 4 ½ months before a throwing program begins. Pitchers return to the mound around 9 months and position players undertake a position-specific protocol around 9 months. Return to competition is between 10 and 12 months.
  • For collision athletes, such as football or lacrosse players, it is 6 months before you are allowed to engage in contact again.

*Note: All timelines are meant as a guide and each player’s actual timeline may vary.*

Shoulder Instability Videos

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