The patellar tendon is the distal portion of the common
tendon
A tendon or sinew is a tough band of fibrous connective tissue, dense fibrous connective tissue that connects skeletal muscle, muscle to bone. It sends the mechanical forces of muscle contraction to the skeletal system, while withstanding tensi ...
of the
quadriceps femoris, which is continued from the
patella to the
tibial tuberosity. It is also sometimes called the patellar ligament as it forms a bone to bone connection when the patella is fully ossified.
Structure
The patellar tendon is a strong, flat ligament, which originates on the apex of the patella distally and adjoining margins of the patella and the rough depression on its posterior surface; below, it inserts on the
tuberosity of the tibia; its superficial fibers are continuous over the front of the patella with those of the tendon of the
quadriceps femoris. It is about 4.5 cm long in adults (range from 3 to 6 cm).
The medial and lateral portions of the
quadriceps tendon
In human anatomy
Human anatomy (gr. ἀνατομία, "dissection", from ἀνά, "up", and τέμνειν, "cut") is primarily the scientific study of the morphology of the human body. Anatomy is subdivided into gross anatomy and micros ...
pass down on either side of the patella to be inserted into the upper extremity of the tibia on either side of the tuberosity; these portions merge into the capsule, as stated above, forming the medial and lateral patellar retinacula.
The posterior surface of the patellar tendon is separated from the
synovial membrane
Synovial () may refer to:
* Synovial fluid
* Synovial joint
A synovial joint, also known as diarthrosis, joins bones or cartilage with a fibrous joint capsule that is continuous with the periosteum of the joined bones, constitutes the outer bou ...
of the
joint
A joint or articulation (or articular surface) is the connection made between bones, ossicles, or other hard structures in the body which link an animal's skeletal system into a functional whole.Saladin, Ken. Anatomy & Physiology. 7th ed. McGraw- ...
by a large infrapatellar pad of fat, and from the tibia by a
bursa
Bursa () is a city in northwestern Turkey and the administrative center of Bursa Province. The fourth-most populous city in Turkey and second-most populous in the Marmara Region, Bursa is one of the industrial centers of the country. Most of ...
.
Clinical significance
The patellar tendon can be injured in a
patellar tendon rupture. Because tendon does not regenerate fully in humans, there is a significant clinical need for research into therapies for patellar tendon rupture.
It can be used as a tissue source in the repair of other ligaments. In the event of a torn
anterior cruciate ligament
The anterior cruciate ligament (ACL) is one of a pair of cruciate ligaments (the other being the posterior cruciate ligament) in the human knee. The two ligaments are called "cruciform" ligaments, as they are arranged in a crossed formation. In ...
, the patellar tendon can be used in the rehabilitation process. In this case, the middle one third of the patellar tendon is harvested and inserted through tunnels that are drilled into the
femur
The femur (; : femurs or femora ), or thigh bone is the only long bone, bone in the thigh — the region of the lower limb between the hip and the knee. In many quadrupeds, four-legged animals the femur is the upper bone of the hindleg.
The Femo ...
and
tibia
The tibia (; : tibiae or tibias), also known as the shinbone or shankbone, is the larger, stronger, and anterior (frontal) of the two Leg bones, bones in the leg below the knee in vertebrates (the other being the fibula, behind and to the outsi ...
. The portion of the patellar tendon is then drawn through these tunnels in the bone and will be affixed to the bone via screws. The recovery process takes approximately 4–6 months upon the completion of surgery. This patellar tendon method of reconstruction was traditionally the gold standard graft for anterior cruciate ligament reconstruction and is still one of the more preferred methods.
[http://www.aaos.org/news/aaosnow/apr12/cover1.asp]
The insertion of the patellar tendon on the tibia is the location of
Osgood–Schlatter disease.
See also
*
Patellar reflex
The patellar reflex, also called the knee reflex or knee-jerk, is a stretch reflex which tests the L2, L3, and L4 segments of the spinal cord. Many animals, most significantly humans, have been seen to have the patellar reflex, including dogs, cat ...
*
Patellar tendinitis
Additional images
File:Gray350.png, Sagittal section of right knee-joint.
File:Gray351.png, Capsule of right knee-joint (distended). Lateral aspect.
References
External links
* - "Muscles of the anterior (extensor) compartment of the leg."
* ()
{{Authority control
Knee ligaments