The most common complication is bleeding into the joint after the arthroscopy. This is expected because the knee joint is pumped with 100 milliliters of fluid and then three large probes are inserted. Infection accounted for 12.1 percent of the complications and blood clots (thromboembolic disease) accounted for 6.9 percent.
 

It should be noted that specific kinds of arthroscopic procedures have their own kinds of complications. For instance, in ACL reconstruction (ligament reconstruction of the knee) all of the following types of complications have been reported: hemarthrosis, hematoma (blood clot), sepsis, skin necrosis, arthrofibrosis (excessive scar tissue), deep venous thrombosis (vein blood clot), recurrent effusion (fluid keeps filling in the knee), sensory nerve injury, reflex sympathetic dystrophy (formation of severe chronic knee pain), tourniquet paralysis, tissue irritation over a metallic device, and compartmental syndrome.
 

The most common complication in ACL reconstruction, however, is arthrofibrosis, resulting in loss of flexion, extension, or both. This means that, after the arthroscopy, the person cannot move the knee normally. It is fibrosed, or scarred down, so normal movement is not possible. The incidence of this has been shown to be as high as 3.7 percent. ACL reconstruction complications also occur due to use of the synthetic or natural grafts. Some people react to both the synthetic and natural grafts and reject them.
 

Shoulder arthroscopy is also fraught with complications. Complications have included nerve injury, Rotator Cuff tear, as well as the usual hemarthrosis and infections.
 

One of the most common arthroscopic procedures is partial meniscectomy, which has a high rate for development of long-term arthritis because of the high pressures generated on the tibial cartilage when the meniscus is removed. Anterior cruciate ligament (ACL) reconstruction is not much better, with a high percentage of athletes not returning to their presurgerical level of athletics, even after a year of rehabilitation. Shoulder arthroscopic surgery is also not very effective at getting the athlete back to playing their sport either, especially if the shoulder joint has some instability. The reason for all of these suboptimal outcomes is because arthroscopy does not heal anything. Arthroscopy typically involves looking into the joint and shaving or removing tissue. This has nothing to do with repairing the damaged area. Even putting in artificial ligaments and tendon grafts, though helpful for some, is not truly repairing the area. Only Prolotherapy, by stimulating the actual proliferation (growth) of normal collagen tissue, will start the normal repair process of the injured ligaments and tendons. It is for this reason that many athletes are saying the verdict is in--say nope to scope and yes to Prolotherapy.