Patella (kneecap) is a small round bone that is located in the front of the knee joint. Patella is easily detectable under the skin. If you straighten the leg, we can see that it moves easily from side to side. The main function of the patella is to prevent displacement of the bones (femur and tibia).
Structure of the patella
Patella «grows» in the large tendon of the quadriceps femoris. Because of this, it is mobile and can move up, down, and side to side. The upper part has a rounded shape and is called the base. And the lower part is elongated and is called the tip. The outer side of the patella is rough to the touch. Ribbed surface provides greater strength and, consequently, better protect the knee from damage. The surface of this bone there is a special hole for blood vessels, as well as places for the attachment of the tendon. On the inner surface have special grooves and bulges, which ensure the congruency of the bones (i.e. the bones touch each other, like a puzzle). The inner side is also divided into two parts: the medial (i.e. inner) and lateral (external).
The lateral side covers a large portion of the patella. This side is also covered with a thick layer of cartilaginous tissue, additionally reducing the load on the joint. Patella is the center of rotation. Thanks to her, it becomes possible to work the quadriceps load on the knee. The pressure exerted on the patella, being very difficult. Due to the special structure of the pressure, tension and compression occurs with minimal friction and is properly distributed.
Patella is supported by ligaments. The ligament of the patella is fixed to its apex and then goes to the tibia. This bone is the tuberosity, where is attached the ligament of the patella. On the femoral and tibial bones of the located grooves, which moves the patella in flexion and extension of the limb. The tabs on the knee Cup block dice, so they are not displaced to the side.
On each side of the knee is cruciate ligaments, which further strengthen and stabilize the joint.
The patella in newborns
Extremely common is a myth that children are born without kneecaps. But in fact it is not. If the kid has no abnormalities in the development of the musculoskeletal system, the kneecap him, of course. It is formed when the child is in the womb, namely 4 months, so the children are born with it.
Why speak about his possible absence? The fact that babies usually have their skeleton consists of cartilage and not of bone. This fabric is still very pliable and weak. Moreover, in newborns bones more than an adult. With time bones grow together and their number becomes standard for all.
The maintenance of the myth also contributes to the bulkiness of the newborn, where the patellar tendon may not be palpable. Therefore, it may seem that children are born without the patella. Over time, the cartilage of the patella, a so-called growth zone, which begins to form bone tissue. And only 6-7 years to the children formed a complete patellar tendon from bone.
Children can be born with various pathologies in the development of the knee and the entire musculoskeletal system, which may occur due to such reasons:
- genetic predisposition;
- diseases and infections;
- failures in a hormonal background.
Most often in children is congenital dysplasia (dislocation) of the joints, clubfoot, which occurs in the absence of the patella. In this case, it required surgery. Dysplasia in children needs prompt treatment, as the displaced bone can restrict the movement of the joint, and also contributes to the deviation of the lower leg. Improper loading due to the displacement can lead to such disease as arthritis.
Patella may be absent in children, but in this case we are talking about a rare condition that is associated with underdevelopment of the tibia and the femur.
Children who do not have only the patella, and no more violations no, operations do not need. Possible weakness and fatigue, but on the overall its absence does not affect. This pathology in children, usually not affects the mobility of limbs.