The knee is a complex joint, classified as a pivotal hinge joint. Dislocation of the knee is often associated with trauma such as collisions involving motor vehicles, motorcycles, and bicycles. Some combat sports target the knee area. Striking arts such as Muay Thai will incorporated kicks to the knee area. Submission arts such as Brazilian Jiu Jitsu have many joint locks that either attack the knee directly (knee bar) or indirectly through torsional movements (heel hook). Due to the nature of combat sports, specifically ones that target the knee for joint manipulation or strikes, it is of this author’s opinion that those practitioners should educate themselves on the anatomy and physiology of the knee.
The anatomy of the knee involves numerous structures to maintain stability. I feel that is important to demonstrate the complexity of the knee-joint by attempting to list some of the structures that comprise it. The bones of the knee area are the femur (thigh bone), tibia (shin bone), and the patella (kneecap). The fibula runs along side the tibia and may sustain injury from traumatic accidents that dislocate the knee. The peroneal nerve and numerous arteries are located in this area. There is the femoral artery, the popliteal artery, the recurrent branch of the tibial artery, as well as five genicular arteries. The ligaments of the knee may be broken down into two groups. The intercapsular group is located inside the knee-joint. This group may include the cruciate ligaments (ACL & PCL), the transverse ligament, the meniscofemoral ligaments, the meniscotibial ligament. The extracapsular group is located around the knee-joint. This group may include the patellar ligament, the patellar retinacula ligaments, the collateral ligaments, and the popliteal ligaments. There are also cartilage formations found in the knee such as the medial and lateral menisci and the hyaline. Other soft tissue structures are the bursa and the synovial and fibrous memebranes of the articular capsule. There are also a large group of muscles involved or in close proximity to the knee-joint. They may include the articularis genu, quadraceps, gastrocnemius, three vastus muscles, bicep and rectus femoris, the sartorius gracilis and the tensor fascia latae.
There are five major classifications of knee dislocations. The anterior dislocation is the most common. It occurs when the tibia is in front of the femur. The posterior dislocation is when the tibia dislocates behind the femur. Medial dislocation is when the tibia dislocates toward the unaffected leg. Lateral dislocation is when the tibia dislocates away from the unaffected leg. Then there is the rotary dislocation. This is the type of dislocation that might occur during a heel hook.
Complications may include fracture to bony structures, damage to the numerous soft tissue structures and loss of limb. In chapter 73 of the book Emergency Medicine Procedures, Sharad Pandit and Zach Kassutto stated, “The incidence of limb loss is greater than 85 percent if the knee is dislocated longer than six to eight hours.” Due to the urgency and possible threat to the limb, further discussion on this injury is beyond the scope of this article.
If you have any concerns about your health and / or well-being, please seek the counsel of a trained professional. Don’t depend on the ramblings of a crazy little blogger nobody, such as myself.
Wikipedia contributors. “Knee.” Wikipedia, The Free Encyclopedia. Wikipedia, The Free Encyclopedia, 12 May. 2011. Web. 14 May. 2011.
Reichmann, Eric F.; Simon, Robert R.; Pandit, Sharad; Kassutto, Zach; “Chapter 73, Knee Joint Dislocation Reduction.” Emergency Medicine Procedures. McGraw-Hill Professional, 2004. 644-647..