Shoulder Reconstruction and Stabilisation

Introduction

The shoulder is a combination of three bones: the humerus (upper arm bone), the clavicle (collarbone), and the scapula (shoulder blade). The ball-like head of the humerus fits into the cup-like end of the scapula known as the glenoid. This cup or glenoid is commonly referred to as the shoulder socket and is surrounded by a rim of soft tissue called the labrum. In order to maintain shoulder stability, the labrum acts like a bumper and is helped by the glenohumeral ligaments and capsule within the shoulder joint

The head of the humerus may be forced out of the glenoid in a dislocation or can be forced partially out of the glenoid, which is known as a subluxation. Repeated dislocation or subluxation of the humerus out of the glenoid is known as instability. Instability is a weakening of the capsule and ligaments of the shoulder joint, which allows the ball to slip out of the socket, causing pain, frustration and doubt in the shoulder as a stable joint. Dislocations and some subluxations often happen from some sort of injury or trauma. Trauma often involves a high energy impact or may result from a fall onto an outstretched hand. Some patients may also have "loose" shoulders that tend to sublux or even dislocate without trauma.

Repetitive overhead throwing can also cause subtle instability with secondary injury to the rotator cuff. Pain from instability can be from the unstable event or can be from overuse of the rotator cuff in an attempt to stabilize the loose shoulder. This is called instability-induced tendonitis, sometimes also called secondary impingement. Another type of instability is internal impingement, which is when the unstable shoulder rotates excessively (such as in a thrower). The rotator cuff bumps up against the glenoid, and it starts to tear the labrum (the tissue on the rim of the glenoid) and the posterior superior rotator cuff.

Both dislocations and subluxations can cause tears of the labrum, ligaments or capsule. They may also cause rotator cuff tears as well as fractures of the shoulder joint. When a traumatic dislocation occurs, and is associated with a tear of the labrum, it is often referred to as a, "Bankart lesion".

Repeated dislocations may cause further tearing of these stabilizing structures and may cause the capsule to stretch out so much that the shoulder remains unstable.

The humerus may be forced out of the glenoid, (a dislocation), or overhead throwing sports may also injure the shoulder joint. Either may cause a SLAP Lesion, which stands for a tear in the Superior Labrum, Anterior to Posterior. In a SLAP Lesion, the labrum is torn from the front to the back. The superior labrum is the attachment for the biceps tendon, the strong muscle in the front of the arm. A sudden pull on this muscle can pull the superior labrum off of the bone.

A tear in the Labrum (Bankart Tear) occurs during dislocation

The labral tear + surrounding bone damage, causes instability and further dislocation, similar to a golf ball falling of a tee.

History

Patients will commonly complain of symptoms of a loose shoulder joint. They may experience popping or grinding of the shoulder. There is often associated pain with certain positions of the arm. In patients who have a history of multiple dislocations, they may even re-dislocate while sleeping or getting dressed. Sometimes dislocations may be reduced by the patient themselves. This is often painful. More commonly, however, dislocations require a reduction in the emergency room supervised by a physician. Most patients who have had even one dislocation will tell you that it is extremely uncomfortable.

A fall on an extended hand held close to the body presents the greatest risk of a SLAP lesion. Overhead sports, such as baseball, volleyball, swimming and weightlifting also increase the chance of the injury. A SLAP lesion may also occur as the result of an automobile accident. Additionally, those with above-average joint laxity, or looseness of the ligaments, stand at great risk of shoulder instability.

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Treatment

After an initial dislocation is reduced, most patients are immobilized in a sling for a week or two and then started on a rehabilitation program. Some patients improve after immobilization followed by rehabilitation. One problem that affects younger patients more frequently is recurrence of dislocation. This means that patients will tend to re-dislocate, especially if they suffer their first dislocation between the ages of 15 and 25 years of age. For younger patients, the re-dislocation rate in the Orthopaedic literature ranges from 60-90%.

Patients older than 40 may suffer a rotator cuff tear with a dislocation rather than suffer recurrence of dislocations.

Strong rotator cuff muscles remain the best defence against shoulder dislocation, subluxation, and, thus, instability. Exercises that build up these muscles around the shoulder should be done. Adequate warm-up before activity and avoidance of high-contact sports may help prevent a recurrence of instability.

When non-operative treatment fails, there are many different surgical options to stabilize the shoulder. These treatments include both open and arthroscopic techniques. Recent Orthopaedic literature has shown that arthroscopic techniques can be as successful as open surgery.

The Operation

The operation is performed arthroscopically (key-hole)
A general anaesthetic is usually used with or without a shoulder block (local anesthetic)
3 small stab incision (8mm) are usually required.

The first stage of the procedure involves inspecting the shoulder joint. There is often other pathology in this area which is addressed at this stage. This may include bicep tendon tears, joint inflammation, labral (cartilage) tears and loose bodies.

The labral tear is then defined. The surrounding bone is roughened to provide a "sticky" surface for the repair. Holes are drilled in the bone and anchors inserted. The anchors are attached to sutures "ropes" which are then stitched to the torn tissue.

In some situations the nearby tissue (capsule) is incorporated into the repair. This may restrict external rotation, but may be required to help with the stability of the shoulder.

Post-Operative

The dressings will be bulky, but can be removed at day 3. Under these bulky dressings, there will be smaller rectangular dressing which need to be left intact until review.

Wound ooze is common and expected. The operation is performed "under water" using a pressure unit designed to increase the "space" to provide safe instrument insertion. The body will resorb most of this fluid, but the wounds will ooze for the first few days.

The wounds should be kept dry otherwise.

The swelling will resolve over the first few days. A shoulder protocol will outline all the post-operative instructions and limitation.

You will be placed in a sling for 4 weeks.
A full copy of the shoulder protocol is available on this website.

Risks and Complications

All surgery carries risk. Although the operation is minimally invasive and using only 8mm incisions, there are some risks to consider.

  1. Infection: The true infection rate is unknown following this surgery but is not common. Symptoms to consider are feeling unwell, fevers, intense pain and pus from the wound. If this occurs please contact the Rooms or the nearest Emergency Department.
  2. Stiffness: All surgery carries a risk of stiffness. This may also be related to the type and extent of the rotator cuff tear. It is important to carefully follow the shoulder guidelines.
  3. Nerve/Artery Damage: Rare, but reported in the literature. If the patient develops tingling, numbness, lack of movement in the hand of change of colour in the limb, immediately contact the Rooms or the emergency department. NOTE: Some patients are given an anesthetic block which will cause numbness but should wear off by 12 hours.
  4. Re-dislocation and pain: The rate of failure is related to a number of factors. Patients who have dislocated multiple times have a higher rate of failure. Often when dislocation happen, bone is lost due to knocking the humerus on the socket. In some cases a bone-transfer procedure may be required to replace the lost bone.
    Patients with inherent laxity (double jointed) have an increase failure rate.
    Not complying with the post-operative instructions may cause anchor or suture"pull-out"
  5. Blood Clots: This is uncommon