What is a Knee Dislocation?
A knee dislocation is an injury that occurs when the tibia and fibula are moved out of their normal position in relation to the femur. A similar injury, known as a “patella dislocation” occurs when the patella (kneecap) is moved out of its position in the patellofemoral groove. These bones are held in place by ligaments, strong bands of connective tissue which stabilise the knee. When the knee is dislocated, the ligaments tear. Dislocations can occur as a result of contact or non-contact trauma, with hyperextension and direct force being the most common mechanisms of injury. Collisions in certain sports, such as soccer, rugby, gymnastics, and ice hockey, frequently result in hyperextensions, while dislocations caused by direct force are more common in the case of motor vehicle accidents/collisions.
Types of Knee Dislocation
Knee dislocations are classified according to their tibial displacement. There are five primary types of dislocations: anterior, posterior, medial, lateral, and rotary. Dislocations of the rotary type can be further classified as anteromedial, anterolateral, posteromedial, and posterolateral. Treatment of posterolateral dislocations is considered extremely difficult, if not outright impossible, via non-surgical methods.
Patella dislocations occur more frequently than knee dislocations and are almost always in the lateral or outside direction. They almost always occur when the knee is extended and there is an external rotation or outwardly-directed force on the leg.
High-velocity dislocations occur when a sudden and extremely violent force impacts the knee. These dislocations are more likely to result in widespread damage to the bones and ligaments. Low-velocity dislocations, on the other hand, are closely associated with sports and/or athletics. They typically result in lower rates of vascular damage or damage to tissues. For this reason, low-velocity dislocations have a more optimistic prognosis than high-velocity dislocations.
Knee Dislocation Symptoms
There are several possible signs and symptoms that manifest when a knee is dislocated. A knee dislocation will cause moderate to severe pain in the knee of the victim, and it may also lead to a loss of feeling below the knee. A dislocation may also be accompanied by prolonged pain in or around the medial (inside) ligaments. Discolouration is also common at the site of the ligament tear. In some cases, a dislocation will be indicated by a deformed appearance; the leg itself may appear crooked or set at an angle. Furthermore, a relocated knee may cause rapid and acute swelling in the event that the relocation occurred by itself.
Knee Dislocation Treatment
There are two basic categories of knee dislocation treatment: operative and non-operative, also called “conservative treatment.” Operative treatment typically involves surgery.
Proper treatment will almost always require a relocation of the knee. An emergency or orthopaedic doctor will move the lower leg back into its normal position in a process referred to as “reduction.” A reduction is typically performed while the patient is under “conscious sedation,” a state in which the patient is sedated enough to withstand the pain/discomfort of the procedure itself, but not enough to lose consciousness. Reduction is a vital step in the healing process, as it enables the repair of damaged nerves, blood vessels, ligaments, and other tissues. In order to prevent further injury and further facilitate the healing process, the entire joint will be placed in a splint or otherwise immobilised. Immobilisation prevents the knee itself from bending and assists in the healing of ligaments and other tissues, and it takes place within a short (between seven and ten days) period of time.
A dislocation sometimes involves broken bones. Extreme cases may necessitate reconstructive surgery in order to fix this. Whether or not this type of surgery is necessary is usually determined once the swelling has subsided, and an orthopaedic doctor (bone specialist) will be responsible for treatment. Additionally, if damage to the arteries has occurred as a result of the dislocation, then an immediate surgical procedure by a trauma or vascular surgeon will be necessary in order to repair the damaged arteries and maintain a healthy blood flow.
Once a knee dislocation has occurred, recurrent dislocations may become commonplace. As previously mentioned, this is frequently the case for athletes. The average age of such occurrences is between sixteen and twenty years old. Conservative treatment can be administered by way of appropriate rest, hip/thigh muscle strengthening, and possibly the use of a patella or knee brace. Self-treatment of a knee dislocation is not recommended, as the most effective reliable treatment is to have a doctor examine the injury and perform a reduction. However, placing ice on the dislocated knee may assist with pain management and a decrease of the swelling.
Recurrent dislocations are most effectively treated with surgery to repair or reconstruct the torn ligaments, so as to allow the athlete unencumbered return to sports.