Table of ContentsView AllTable of ContentsBonesCartilageLigamentsMuscles and TendonsJoint Capsule and LiningJoint BursaFunctionCommon Knee ConditionsNext in Home Office Ergonomics GuideThe 15 Best Knee Braces To Keep You Moving
Table of ContentsView All
View All
Table of Contents
Bones
Cartilage
Ligaments
Muscles and Tendons
Joint Capsule and Lining
Joint Bursa
Function
Common Knee Conditions
Next in Home Office Ergonomics Guide
Knee anatomy involves more than just muscles and bones. Ligaments, tendons, and cartilage work together to connect the thigh bone, shin bone, and knee cap and allow the leg to bend back and forth like a hinge.
The largest joint in the body, the knee is also one of the most easily injured.Problemswith any part of the knee’s anatomy can result in knee pain, stiffness, and difficulty walking.
This article details knee anatomy. It explains the different parts that make up the knee joint, how the knee works, and common knee problems.
Bones Around the Knee
Three important bones come together at the knee joint:
A fourth bone, thefibula, is located just next to the tibia and knee joint, and can play an important role in some knee conditions.
The tibia, femur, and patella all are covered with a smooth layer of cartilage where they contact each other at the knee joint.
There is also a small bone called a fabella, that is often located behind the knee joint. The fabella is a type of bone called a sesamoid bone (meaning it sits within a tendon). It’s of little consequence to the function of the knee joint and is only found in about 25% of the population.
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Cartilage of the Knee
There are two types of cartilage in the knee joint:
Ligaments of the Knee
Ligaments are structures that connect two bones together. There are four majorligamentsthat surround the knee joint.
Two of these ligaments are in the center of the joint, and they cross each other. These are called the cruciate ligaments and consist of the anterior cruciate ligament and the posterior cruciate ligament.
One ligament is on each side of the knee joint—the medial collateral ligament on the inner side and the lateral collateral ligament on the outer side. Ligament injuries typically result incomplaints of instabilityof the knee joint.
Anatomy of the Knee
Muscles propel the knee joint back and forth. A tendon connects the muscle to the bone. When the muscle contracts, the tendons are pulled, and the bone is moved.
The patellar tendon on the front of the knee is part of the quadriceps mechanism. Other smaller muscles and tendons surround the knee joint as well.
Thesynoviumis the lining of the joint space. The synovium is a layer of tissue that defines the joint space.
The synovial cells produce a slippery, viscous fluid called synovial fluid within the joint. In conditions that cause inflammation of the joint, there can be an abundance of synovial fluid produced, which leads to swelling of the knee joint.
Abursais a structure in your body that is placed between two moving parts. In your knee, there is a prominent bursa just in front of your knee and underneath the skin.
The bursa functions as a means to allow for smooth movement between these two structures (skin and bone). There are actually hundreds of bursae spread throughout your body.
The bursa in front of the kneecap is prone to swelling, especially when people injure their knees or perform activities that involve kneeling on hard surfaces. Inflammation of the bursa, called prepatellar bursitis, is common in people who do flooring work or cleaning work and have to spend a lot of time kneeling.
Knee Joint Function
However, the knee does not only bend back and forth. There are also rotational movements at the knee joint.
In order for the knee joint to function properly, there needs to be good stability of the joint throughout its range of motion. If there are restrictions in mobility or instability of the knee joint, the function will not be normal.
A normally functioning knee joint will allow the following:
These are just some of the important functions that the knee joint allows. In order for any one of these functions to behave normally, all of the aforementioned structures need to be working together—and functioning normally.
Knee pain, decreased range of motion, and functional problems can be due to a number of conditions, including:
Causes and Treatments for Bilateral Knee Pain
A Word From Verywell
The knee joint is acomplex structurethat involves bones, tendons, ligaments, muscles, and other structures for normal function. When there is damage to one of the structures that surround the knee joint, this can lead to discomfort and disability. Understanding the normal function of the knee joint can help you address some of these common conditions.
5 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.American Academy of Orthopaedic Surgeons: OrthoInfo.Common knee injuries.U.S. National Library of Medicine: MedlinePlus.Meniscus tears–aftercare.American Academy of Orthpaedic Surgeons: Ortho Info.Synovial Chondromatosis.National Institute of Health: News in Health.Beating Bursitis: Take Care of Your Joint Cushions.U.S. National Library of Medicine: MedlinePlus.Knee Injuries.Additional ReadingBronstein RD, Schaffer JC.Physical Examination of the Knee: Meniscus, Cartilage, and Patellofemoral Conditions.J Am Acad Orthop Surg. 2017;25(5):365-374. doi:10.5435/JAAOS-D-15-00464
5 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.American Academy of Orthopaedic Surgeons: OrthoInfo.Common knee injuries.U.S. National Library of Medicine: MedlinePlus.Meniscus tears–aftercare.American Academy of Orthpaedic Surgeons: Ortho Info.Synovial Chondromatosis.National Institute of Health: News in Health.Beating Bursitis: Take Care of Your Joint Cushions.U.S. National Library of Medicine: MedlinePlus.Knee Injuries.Additional ReadingBronstein RD, Schaffer JC.Physical Examination of the Knee: Meniscus, Cartilage, and Patellofemoral Conditions.J Am Acad Orthop Surg. 2017;25(5):365-374. doi:10.5435/JAAOS-D-15-00464
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
American Academy of Orthopaedic Surgeons: OrthoInfo.Common knee injuries.U.S. National Library of Medicine: MedlinePlus.Meniscus tears–aftercare.American Academy of Orthpaedic Surgeons: Ortho Info.Synovial Chondromatosis.National Institute of Health: News in Health.Beating Bursitis: Take Care of Your Joint Cushions.U.S. National Library of Medicine: MedlinePlus.Knee Injuries.
American Academy of Orthopaedic Surgeons: OrthoInfo.Common knee injuries.
U.S. National Library of Medicine: MedlinePlus.Meniscus tears–aftercare.
American Academy of Orthpaedic Surgeons: Ortho Info.Synovial Chondromatosis.
National Institute of Health: News in Health.Beating Bursitis: Take Care of Your Joint Cushions.
U.S. National Library of Medicine: MedlinePlus.Knee Injuries.
Bronstein RD, Schaffer JC.Physical Examination of the Knee: Meniscus, Cartilage, and Patellofemoral Conditions.J Am Acad Orthop Surg. 2017;25(5):365-374. doi:10.5435/JAAOS-D-15-00464
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