Knee arthroscopy is a procedure involving the insertion of a camera into the knee joint to assist the orthopedic surgeon in better diagnosis and treatment of knee pathology. A tourniquet is used by many surgeons to decrease blood flow to the knee, which can theoretically hamper visualization of the joint. Like all surgical interventions, arthroscopy carries its own risks with or without the tourniquet.
Contraindications to Tourniquet Use
Patients with a history of thrombophlebitis, or blood clots, causing inflammation in the veins, and those with peripheral blood vessel disease should not undergo tourniquet use during surgery. If you already have a decreased blood supply to the lower limb, as in vascular disease, further decreasing blood flow is not usually a good idea. Also, if you have a history of clot formation, the tourniquet can increase the risk of a clot forming in the deep veins of the leg, which is a huge risk factor for the clot dislodging and ending up in the lungs (pulmonary embolus), a potentially fatal event.
Paresis (Impaired Movement)
Damage can result as a result of decreased blood flow (ischemia) to the nerves of the lower limb. When the tourniquet time exceeds 90 to 120 minutes, nerve damage can result and manifest as difficulty in moving the limb. Keeping tourniquet time under 90 to 120 minutes--or not using it at all--can help prevent this complication.
Muscle Injury
Similar to the mechanism of damage to nerves, decreased blood flow to the lower limb can damage muscle as well. If this is suspected, the clinician can check blood levels and increased creatine phosphokinase (enzyme that is released when muscle is injured) levels that point toward definite muscle damage. In addition, when the blood re-enters previously depleted muscle, it can cause swelling and, if it is serious enough, increase pressure in the muscle compartment. "Compartment syndrome" can result. This is a limb-threatening emergency and must be evaluated and treated vigorously.
Infection
Like all surgical interventions, infection is a possible complication. It is rare in arthroscopy and usually attributed to breaks in sterile technique. It can warrant aggressive antibiotic usage and surgical debridement, if severe.
Synovial Fistula
A synovial fistula occurs between the joint cavity and the external skin and carries an increased risk of infection. These are rare. Usually, immobilization of the knee for seven to 10 days will allow the fistula to close spontaneously.
References
- "The Knee" journal; A Meta-Analysis of Tourniquet-Assisted Arthroscopic Knee Surgery;" T. Smith; Oct. 1, 2009.
- "DeLee and Drez's Orthopaedic Sports Medicine, 3rd Edition;" Jesse C. DeLee; 2009.
- "Campbell's Operative Orthopaedics, 11th Edition;" S. Terry Canale and James H. Beaty; 2007.
