Shoulder instability is a chronic condition that causes frequent dislocations of the shoulder joint. As the shoulder dislocates it tears a portion of the cartilage bump in the front of the socket. This lesion is called the Bankart’s lesion. If this cartilage does not heal back, it can cause recurrent dislocation of the shoulder. If the cartilage tears with a portion of the underlying bone it is called a Bony Bankart. A similar injury in the back of the shoulder when the shoulder dislocates to the back is called a Reverse Bankart’s lesion. Rarely the shoulder can dislocate inferiorly and tear the cartilage below. A chronic pull of the biceps tendon which is attached to the upper end of the socket can pull off the upper portion of the rim of the socket. This is called a SLAP tear (acronym for Superior Labrum Anterior Posterior).
The risk factors that increase the chances of developing shoulder instability include:
- Injury or trauma to the shoulder at a young age
- Repetitive overhead contact sports such as baseball, swimming, volleyball, or weightlifting
- Loose or lax shoulder ligaments
The common symptoms of shoulder instability include pain with certain movements of the shoulder; popping or grinding sound may be heard or felt, swelling, and bruising of the shoulder may be seen immediately following subluxation or dislocation. Visible deformity and loss of function of the shoulder occurs after subluxation or sensation changes such as numbness over the outer aspect of the shoulder or even partial paralysis can occur after the dislocation because of pressure on nerves and blood vessels.
Dr Bala may examine to assess the degree and direction of instability of the shoulder.
He may also examine for evidence of laxity of other joints, skin or of the entire connective tissue of the body. MR and or CT Arthrograms are the standard investigation of choice to evaluate soft tissue and bony defects preventing shoulder stability.
Conservative (Non-operative) Treatment
The goal of conservative treatment for shoulder instability is to restore stability, strength, and full range of motion. Conservative treatment measures may include the following:
- Closed Reduction: Following a dislocation, Dr Bala can manipulate the shoulder joint, usually under anaesthesia, realigning it into proper position.
- Medications: Over the counter pain medications and NSAIDs can help reduce the pain and swelling.
- Rest: Rest the injured shoulder and avoid activities that require overhead motion. A sling may be worn for 2 weeks to facilitate healing
- Physiotherapy: To strengthen the muscles around the shoulder and improve range of motion and function.
When the conservative treatment options fail to relieve shoulder instability, or if the dislocations have become too frequent and hindering quality of life, Dr Bala may recommend shoulder stabilisation surgery. Repair of the Bankart’s lesion can be done either open (Open Bankart’s repair) or through keyhole surgery (Arthroscopic Bankart’s repair). Arthroscopy is a surgical procedure in which an arthroscope (a small tube with a light and video camera at the end) is inserted into a joint to evaluate and treat the condition. The torn ligaments can be repaired (stitched) back to the socket (glenoid) and secured with bone anchors, which are small plastic plugs. Sometimes a large defect in the upper end of the arm bone (Hill Sachs lesion) is treated during surgery where the shoulder tendons are pulled into the defect to fill it (Remplissage technique). Dr Bala has been trained in shoulder arthroscopic stabilisation with techniques his mentors have acquired from the Codman Shoulder Institute, Mayo Clinic, USA.
Symptomatic SLAP tears might need a keyhole repair like the Bankart’s repair described above. In addition to this repair the biceps tendon within the joint, if tendinotic, is usually cut and fixed to the arm bone outside the joint. This can be done keyhole or open. Dr Bala prefers to use a device called the Pec button for his Biceps tenodesis procedures.
In some instances, Dr Bala may recommend a surgical procedure called the Latarjet procedure where a small piece of bone (coracoid) from the front of the shoulder blade with muscle attached, is passed through split muscle and fixed onto the socket of the shoulder joint with screws. This surgery is now possible through keyhole surgery also (Arthroscopic Latarjet procedure).
Rarely there may be bone loss in the socket of the shoulder where the bone loss is augmented with bone either harvested from the waist bone or from another donor.