The patellar tendon is the distal portion of the common

tendon A tendon or sinew is a tough, high-tensile-strength band of dense fibrous connective tissue that connects muscle to bone. It is able to transmit the mechanical forces of muscle contraction to the skeletal system without sacrificing its ability ...

of the

quadriceps femoris The quadriceps femoris muscle (, also called the quadriceps extensor, quadriceps or quads) is a large muscle group that includes the four prevailing muscles on the front of the thigh. It is the sole extensor muscle of the knee, forming a large ...

, 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 The tuberosity of the tibia or tibial tuberosity or tibial tubercle is an elevation on the proximal, anterior aspect of the tibia, just below where the anterior surfaces of the lateral and medial tibial condyles end. Structure The tuberosity o ...

; its superficial fibers are continuous over the front of the patella with those of the tendon of the

. 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, the quadriceps tendon works with the quadriceps muscle to extend the leg. All four parts of the quadriceps muscle attach to the shin via the patella (knee cap), where the quadriceps tendon becomes the patellar ligament. It att ...

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 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.

Clinical significance

The patellar tendon can be injured in a

patellar tendon rupture Patellar tendon rupture is a tear of the tendon that connects the knee cap (patella) to the tibia. Often there is sudden onset of pain and walking is difficult. In a complete rupture, the ability to extend that knee is decreased. A pop may be felt ...

. 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 ligament Cruciate ligaments (also cruciform ligaments) are pairs of ligaments arranged like a letter X. They occur in several joints of the body, such as the knee joint and th ...

, 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 (; ), or thigh bone, is the proximal bone of the hindlimb in tetrapod vertebrates. The head of the femur articulates with the acetabulum in the pelvic bone forming the hip joint, while the distal part of the femur articulates wit ...

and tibia. 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 Osgood–Schlatter disease (OSD) is inflammation of the patellar ligament at the tibial tuberosity (apophysitis). It is characterized by a painful bump just below the knee that is worse with activity and better with rest. Episodes of pain typica ...

Additional images

File:Gray350.png, Sagittal section of right knee-joint. File:Gray351.png, Capsule of right knee-joint (distended). Lateral aspect. File:Slide2ast.JPG, PATELLAR TENDON. Deep dissection. Anterior view.

References

External links

* - "Muscles of the anterior (extensor) compartment of the leg." * () {{Authority control Knee ligaments

Structure

Clinical significance

See also

Additional images

References

External links