Shoulder arthroscopy is a minimally invasive technique that allows orthopaedic surgeons to assess - and in some cases, treat - a range of conditions affecting the shoulder joint.
During the procedure, the orthopedic surgeon makes small incisions or portals in the affected joint, and then inserts a tiny camera and fiber optics to light the interior space. Pictures obtained with the camera are then projected onto a screen in the operating suite.
Shoulder and Scope
Early use of arthroscopy focused on the knee; it might come as a surprise that the first arthroscopic evaluation of a knee actually took place in 1918. (This involved the insertion of the scope into a joint, without the benefit of additional lighting.)
Additional efforts were made during the following decades, but it was not until surgeons were able to obtain adequate lighting with fiberoptic technology (in the 1970s and 1980s), that arthroscopy became truly useful. Instruments and techniques that yielded good results in the knee were adapted by orthopedic surgeons who specialized in the shoulder some seven or eight years later.
"As in the knee, use of arthroscopy in the shoulder started with diagnostic evaluation and has progressed to include therapeutic applications," says Russell Warren, MD, who is an attending orthopaedic surgeon at HSS.
While many people think of the shoulder as a single joint, it is actually made up of two joints: the acromioclavicular joint, where the acromion of the shoulder blade and the collarbone (clavicle) meet, and the gleno-humeral joint, where the head of the humerus (the upper bone in the arm) meets the glenoid, the cup-like portion of the scapula.
There is also potential space (the subacromial space) between the acromion and rotator cuff tendon. Injuries to the shoulder may occur in either joint or in the soft tissues that support and stabilize it.
Anatomy of the Shoulder
SLAP (Superior Labrum Anterior Posterior) lesion which affects the labrum, a rim of cartilage that surrounds the glenoid, was detected in the mid-1980s during arthroscopic evaluations. (This painful condition can also be treated arthroscopically.) As with diagnostic evaluations, therapeutic applications of arthroscopy can remove the need for large incisions. Early treatment attempts focused on repairs of the labrum. Labral tears are just one injury that contribute to shoulder instability, a condition which can lead to subluxation (partial dislocation) or dislocation of the shoulder.
Today, arthroscopy is used in a number of shoulder procedures. Dr. Warren and his colleagues at HSS are among the pioneers in this field. In the early 1990s, they began employing the technique for repair of tears to the rotator cuff, the complex of tendons and muscles that provide stability to the shoulder. Tears may occur in any one of the tendons that connect the three large muscles: the supraspinatus, the intraspinatus, and the subscapularis. Gradually, techniques and instrumentation were developed that allow for all aspects of the repair to be done with arthroscopy alone or with a small incision ("mini-open" procedures).
Rotator cuff surgery may involve a number of steps, including debridement or removal of any loose tissue fragments in the area. The acromion may require smoothing or a portion of the bones forming the acromio-clavicular (AC) joint may need to be removed. If it is inflamed, a bursa (a fluid-filled sac that provides cushioning in the joint) may also be removed (bursectomy). Finally, the loose portion of the tendon is sutured and anchored to the humerus. (If the cuff is badly damaged, the patient may require rotator cuff reconstruction with a tendon obtained from elsewhere in the body.)
Over the last decade, these surgeries have yielded excellent results. Dr. Warren now performs up to 95% of rotator cuff repairs arthroscopically. This technique has evolved into a widely used - and very popular - method at other institutions as well, though augmentation of a cuff repair will occasionally be required.
Other conditions in the shoulder that may be diagnosed and treated with the help of arthroscopy include:
Looking to the future, Dr. Warren anticipates that some of the arthroscopic treatments now used regularly at more specialized institutions like HSS will gradually come into use in community hospitals.
"However," he cautions, "when contemplating surgery, it's important to be sure the orthopaedic surgeon is properly trained and experienced." Dr. Warren also notes that the instrumentation being used in arthroscopic surgeries is becoming better and better, including devices that help place and secure sutures such as those done in rotator cuff repair.
Summary Prepared by Nancy Novick