In its simplest form this involves direct visualization of the structures inside a joint through a tube. Modern arthroscopes have improved sources of light, and the image is magnified and transmitted to a video screen via a fiberoptic cable. Instruments can be inserted through separate entry points around a joint, improving surgery by a technique known as triangulation.

Arthroscopy is used both to obtain a clear view of anatomical abnormalities that may be the cause of a patient’s symptoms and to perform surgery to correct the abnormalities. As recently as the 1960s the value of arthroscopy was still being debated in the United States.

However, with improvements in instrumentation and video technology as well as the diagnostic and therapeutic techniques, it has evolved into a widely used and valuable procedure. Although arthroscopic diagnosis has been partially displaced by MRI over the last decade, the role of arthroscopic surgery is continually expanding.

Advantages include precise diagnosis, very small skin and joint capsule incisions, relatively brief disability and rapid rehabilitation, as well as a better cosmetic outcome than open surgery. Many arthroscopic procedures can be performed under regional anesthesia, and most patients are discharged home on the same day.

The risk of infection is lower than with open surgery. The knee is a large accessible joint with complex internal organization subject to large stresses that frequently lead to structural abnormalities. It is thus the ideal joint for this type of procedure. The first arthroscopy was performed on the knee using a modified cystoscope (used for looking into the bladder) in Japan in 1931.

Lesions in the knee that are amenable to arthroscopic surgery include meniscal injury or degeneration, ligament injury, OSTEOCHONDRITIS DISSECANS, LOOSE BODIES, PATELLOFEMORAL DISORDERS, synovial diseases, OSTEOARTHRITIS, and fractures of the surface of the tibia. Although most arthroscopic surgery has been done on the knee, several other joints are also suitable.

In the shoulder, tears of the glenoid labrum (the rim of supporting cartilage around the shoulder joint), capsule, BICEPS TENDON, or ROTATOR CUFF may be identified and repaired. Loose bodies can be removed and synovial or joint surface abnormalities repaired.

Arthroscopic surgery is particularly useful in the subacromial space just above the shoulder joint where the rotator cuff tendons can be repaired and the undersurface of the acromion and acromioclavicular joint can be smoothed without disrupting the overlying muscles.

Arthroscopy is frequently used at the elbow to remove loose bodies and osteophytes. The cause of chronic wrist pain can be very difficult to determine, and special arthroscopes have been developed to assist with this. In the ankle, arthroscopy is helpful in diagnosing difficult ankle problems as well as treating synovial impingement, loose bodies, osteophytes, and irregularities caused by healed hairline fractures.

Although arthroscopy has been less frequently employed at the hip, the potential benefits from avoiding open surgical exposure of this deep joint suggest that it will continue to have a role despite the disadvantages of limited maneuverability and a small joint space.