The kneecap (Patella) is an oval-shaped sesamoid bone. Sesamoid bones are embedded within tendons. The kneecap is embedded within the quadricep tendon. It’s location allows the tendon to exert more leverage on the femur. The kneecap has two joints, the patellofemoral and the tibiofemoral. The names of the joints reflect the long bones that connect to the kneecap. The femur aka thigh bone and the tibia aka the shin. Other soft tissue structures include but are not limited to, the patello femoral, the lateral collateral ligaments.
Dislocations of the kneecap may be caused by blunt trauma or an odd twisting of the knee. It is a common injury, especially in athletes that are young and / or female. About a quarter of the people who dislocate their kneecaps will have a family history of the injury. There are genetic and anatomical factors that increase the risk of such an injury. Kneecap dislocations have about five classifications depending on your information source. Medial (side located beside other leg) and lateral (side opposite of your other leg) dislocations may possibly be reset without surgical procedures. However, superior (above the knee), Horizontal (tilted outward), and intercondylar (between the femur and tibia) may likely require a surgical procedure. Some kneecap dislocations will slip back into place on their own when the knee is straightened.
There are risks of associated injuries and complications. Initially, there may be pain, swelling, bone fractures, hyper-elasticity of the joint, compromised nerves and / or blood vessels. Delayed complications may include instability and recurrent dislocations, tracking abnormalities, and degenerative arthritis. After the kneecap is reset, a doctor may recommend rest, ice, elevation and NSAIDs (non-steroidal anti-inflammatory drugs). The injured person may have to wear a splint or cast. A doctor may provide walking aids such as cruthes, and order physical therapy.
A physical therapy program may take six to sixteen weeks. It may include strengthening, proprioceptive, and isometric rehabilitation. A physical therapist may also work to improve the knee’s flexibility and range of motion. For athletes, they may utilize sport specific therapy.
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.
Reichmann, Eric F., Simon, Robert R., Kling, Mark P., “Chapter 72, Patellar Dislocation Reduction.” Emergency Medicine Procedures. McGraw-Hill Professional, 2004. 640-644.