Your shoulder is a complex joint that is capable of more motion than any other joint in your body. It is made up of three bones: your upper arm bone (humerus), your shoulder blade (scapula), and your collarbone (clavicle).
Ball and socket. The head of your upper arm bone fits into a rounded socket in your shoulder blade. This socket is called the glenoid. A slippery tissue called articular cartilage covers the surface of the ball and the socket. It creates a smooth, frictionless surface that helps the bones glide easily across each other.
The glenoid is ringed by strong fibrous cartilage called the labrum. The labrum forms a gasket around the socket, adds stability, and cushions the joint.
Shoulder capsule. The joint is surrounded by bands of tissue called ligaments. They form a capsule that holds the joint together. The undersurface of the capsule is lined by a thin membrane called the synovium. It produces synovial fluid that lubricates the shoulder joint.
Rotator cuff. Four tendons surround the shoulder capsule and help keep your arm bone centered in your shoulder socket. This thick tendon material is called the rotator cuff. The cuff covers the head of the humerus and attaches it to your shoulder blade.
Bursa. There is a lubricating sac called a bursa between the rotator cuff and the bone on top of your shoulder (acromion). The bursa helps the rotator cuff tendons glide smoothly when you move your arm.
Your doctor may recommend shoulder arthroscopy if you have a painful condition that does not respond to nonsurgical treatment. Nonsurgical treatment includes rest, physical therapy, and medications or injections that can reduce inflammation. Inflammation is one of your body’s normal reactions to injury or disease. In an injured or diseased shoulder joint, inflammation causes swelling, pain, and stiffness.
Injury, overuse, and age-related wear and tear are responsible for most shoulder problems. Shoulder arthroscopy may relieve painful symptoms of many problems that damage the rotator cuff tendons, labrum, articular cartilage, and other soft tissues surrounding the joint.
Common arthroscopic procedures include:
- Rotator cuff repair
- Bone spur removal
- Removal or repair of the labrum
- Repair of ligaments
- Removal of inflamed tissue or loose cartilage
- Repair for recurrent shoulder dislocation
Less common procedures such as nerve release, fracture repair, and cyst excision can also be performed using an arthroscope. Some surgical procedures, such as shoulder replacement, still require open surgery with more extensive incisions.
Positioning and Preparation
Once in the operating room, you will be positioned so that your surgeon can easily adjust the arthroscope to have a clear view of the inside of your shoulder. The two most common patient positions for arthroscopic shoulder surgery are:
- Beach chair position. This is a semi-seated position similar to sitting in a reclining chair.
- Lateral decubitius position. In this position the patient lies on his or her side on an operating table.
Each position has some slight advantages. Surgeons select positions based on the procedure being performed, as well as their individual training.
Once you are positioned, the surgical team will remove hair, if needed, and then spread an antiseptic solution over your shoulder to clean the skin. They will cover your shoulder and arm with sterile drapes, and will most likely place your forearm in a holding device to ensure your arm stays still.
Your surgeon will first inject fluid into the shoulder to inflate the joint. This makes it easier to see all the structures of your shoulder through the arthroscope. Then your surgeon will make a small puncture in your shoulder (about the size of a buttonhole) for the arthroscope. Fluid flows through the arthroscope to keep the view clear and control any bleeding. Images from the arthroscope are projected on the video screen showing your surgeon the inside of your shoulder and any damage.
Once the problem is clearly identified, your surgeon will insert other small instruments through separate incisions to repair it. Specialized instruments are used for tasks like shaving, cutting, grasping, suture passing, and knot tying. In many cases, special devices are used to anchor stitches into bone.