The shoulder is a ball and socket joint. Most shoulder movement occurs where the ball at the top of your arm bone (the Humerus) fits into the socket (the Glenoid). The socket is part of the shoulder blade (Scapula) which is where the rest of the movement comes from and plays a key role in the functionality of our upper limbs.
The socket is deepened and stabilised by the Glenoid Labrum. The Glenoid Labrum is a firm rim structure that forms a ring around the glenoid cavity (the cup of the ball and socket shoulder joint).
The Labrum’s functions:
If the Labrum is torn, the shoulder can become unstable. This is what happens in shoulder dislocations and instability. Different injury mechanisms cause different tears in various sites around the Labrum. These are given specific descriptive names (below). We also define the site of the tears by describing the glenoid face as a clock, where the top is 12 o’clock, 3 o’clock is at the front and 9 o’clock is at the back (for ease of use this applies to both left and right shoulders).
Bankart lesion – If the tear is at the front of the shoulder, 3 o’clock to 6 o’clock.
SLAP tear (Superior Lesion Anterior to Posterior – is when the tear is at the top of the shoulder, 1 o’clock to 11 o’clock.
Reverse Bankart Lesion – posterior tear, 6 o’clock to 11 o’clock.
270 degree tear – when a tear is a combination of Bankart, Reverse Bankart tear and SLAP tear.
Bankart lesions or tears are common in younger people who dislocate their shoulder. This type of torn Labrum occurs in the lower portion of the glenoid socket.
A person who has sustained a Bankart tear may feel as though their shoulder could fall out of place if they move their arm in a certain way.
SLAP tears go from the front to the back of the cartilage in the middle of the glenoid. Among athletes, this tear is more likely to occur in those who play tennis, baseball, or softball, as these sports involve quick snapping arm movements over the top of the shoulder.
Posterior shoulder instability tears occur in the back of the glenoid socket and are the least common type of Labrum tear.
For more information on the Labrum tears, please click here which takes you to website of Professor Lennard Funk who is a Shoulder & Upper Limb Specialist and Consultant Orthopedic Surgeon in the UK. All of these tears account for approximately 5–10% of all shoulder instability injuries. They can occur due to a severe injury or if a shoulder dislocates posteriorly. Also, tear can take place indirectly as a result of other injuries or symptoms, such as electrocution or seizures, which cause sudden shoulder movements.
A Hill-Sachs lesion can also occur which is a compression fracture or “dent” of the posterosuperolateral (top, rear portion of the ‘ball’) humeral head that occurs in association with anterior instability or dislocation of the Glenohumeral joint. Yiannakopoulos et al. (2007) found Hill-Sachs lesions in 65% of acute dislocations and 93% in patients with recurrent instability.
A common symptom of a shoulder Labrum tear is pain. A person may also experience the following symptoms:
Diagnosing a labral tear is most often done by taking a thorough case history. If it is known that a heavy trauma has occurred, this makes it more likely that a Labral tear has occurred. Also, if the patient is younger and played a competitive overhead sport, this could also be suggestive of labral tear.
The team may recommend an MRI scan which can identify and confirm more severe labral tears, however, smaller Grade I labral tears are often not visible on a normal MRI.
Until the doctor is able to determine a final diagnosis, you might be given a prescription of anti-inflammatory medications to help relieve symptoms.
Instead of trying to move the shoulder all around, you need to give it time to rest and relax. Stop trying to play sport with it, and simply follow the rehabilitation advice from your therapist.
Rehabilitation exercises in the early stages work to mobilize the shoulder and to reduce inflammation. Later, they can also help to strengthen the rotator cuff muscles. When the muscles are strengthened, they are vital to providing stability, strength and function of the shoulder. Athletes are often able to begin partaking in sport-specific exercises 12 weeks after the surgery, but it normally takes four to six months for the shoulder to heal fully.
The procedure aims to tighten and/or repair the over-stretched and injured ligaments, rim of cartilage/Labrum and shape of socket. Different types of operation can achieve this. The surgical options are discussed by the Orthopaedic team with your best interests at the forefront of the decision making. Your post-operative rehabilitation will depend on the specific operation performed however our Physiotherapists can help you through this regardless.
Yiannakopoulos CK, Mataragas E, Antonogiannakis E. A comparison of the spectrum of intra-articular lesions in acute and chronic anterior shoulder instability. Arthroscopy: The Journal of Arthroscopic & Related Surgery 2007;23(9):985-90.