Shoulder surgery for instability conditions (SLAP/Labrum)
Orthopaedic Surgeon – Dr Chien-Wen Liew
Instability in the shoulder occurs due to multiple reasons. In general, most cases are caused by sporting injuries that occur when the shoulder is moved into an abnormal position quickly. This can cause a dislocated or subluxated shoulder. When the shoulder dislocates almost always there is soft tissue injury around the shoulder joint. In young patients, this often requires surgery. One of the most common type of instability injury in the shoulder is called a Bankart lesion. Bankarts are either bony or soft tissue or both. A Bankart lesion means a separation of the labrum from the bone, or a fracture of the bone just under the labrum.
Other causes of injury to the shoulder lead to SLAP tears. A SLAP lesion is due to a tearing of the labrum at the top of the socket part of the shoulder. Its significance is that it involves one of the attachments of the biceps muscle of the arm.
In some cases, the humeral head is also damaged, causing what is called a Hills Sachs lesion. A Hills Sachs lesion is essentially a dent in the humeral head (Ball part of the shoulder joint). This is caused when the shoulder dislocates and the humeral head dents itself on the glenoid (Cup part of the shoulder joint). Sometimes the cartilage is ripped off during this process and loose fragments of cartilage are left inside the joint.
Instability of the shoulder occurs when the normal ability of the structures in the shoulder cannot hold the shoulder in the correct position. This means that the shoulder is either prone to dislocating (i.e. in a Bankart), or the labrum is loose, causing pain (i.e. SLAP tear). A surgeon will take a thorough history about your shoulder and decide whether or not you require a surgery. Often, the first step is a course of physiotherapy to improve range of movement and supporting muscle strength. In most cases of dislocation or SLAP tears in young patients, the shoulder will require surgery to refix the labrum back onto the glenoid (The glenoid is the bony component of the cup side of the shoulder).
The labrum is a ligamentous structure that runs around the glenoid and serves many important roles. It deepens the cup to provide stability, it creates a negative pressure seal around the cup to increase stability, and it acts at the attachment to the long head of biceps.
Prior to surgery being performed on the shoulder, an MRI will be performed to determine if there is any other injured structure of the shoulder. This may involve the rotator cuff tendons or bony injuries. After this assessment, surgery can be planned.
A shoulder arthroscopy is “key hole” surgery. It is a minimally invasive method of inspecting the entire shoulder joint and fixing shoulder instability conditions. It is very useful as it gives a better view of all of the shoulder than an open approach as the camera is slightly angled to look around corners. Once the shoulder has been inspected and all of the areas have been assessed for damage, the repair takes place. A repair of the labrum is the most common treatment for instability conditions. In general, several anchors are placed in the glenoid to hold down the labrum. If the shoulder is very unstable, the capsule in front of the labrum is also brought into the repair to tighten the stretched structures and increase the success of the operation.
There are specific conditions that require specialised sports injury care. This includes posterior labral injuries. They are treated in a similar manner, however require attention to the posterior pocket of tissue at the back of the shoulder. This should never be tightened significantly as it can cause severe limitations in range of movement.
In sports injury of the shoulder, there are many variations in the type of surgery required to stabilise the shoulder. If you have dislocated your shoulder or wish to discuss your SLAP lesion, please contact the office of Dr Chien-Wen Liew on (08) 7099 0188 or make an appointment through the contact form.