Knee Anatomy
Knee Anatomy
The knee is a complex joint made up of different structures - bones, tendons, ligaments, and muscles. They all work together to maintain the knee’s normal function and provide stability to the knee during movement.
Having a well-functioning healthy knee is essential for our mobility and ability to participate in various activities. Understanding the anatomy of the knee enhances your ability to discuss and choose the right treatment procedure for knee problems with your doctor.
Bones of the Knee
The knee is a hinge joint made up of two bones, the thighbone (femur) and shinbone (tibia). There are two round knobs at the end of the femur called femoral condyles that articulate with the flat surface of the tibia called the tibial plateau. The tibial plateau on the inside of the leg is called the medial tibial plateau and on the outside of the leg, the lateral tibial plateau.
The two femoral condyles form a groove on the front (anterior) side of the knee called the patellofemoral groove. A small bone called the patella sits in this groove and forms the kneecap. It acts as a shield and protects the knee joint from direct trauma.
A fourth bone called the fibula is the other bone of the lower leg. This forms a small joint with the tibia. This joint has very little movement and is not considered a part of the main joint of the knee.
Articular Cartilage and Menisci of the Knee
Movement of the bones causes friction between the articulating surfaces. To reduce this friction, all articulating surfaces involved in the movement are covered with a white, shiny, slippery layer called articular cartilage. The articulating surface of the femoral condyles, tibial plateaus and the back of the patella are covered with this cartilage. The cartilage provides a smooth surface that facilitates easy movement.
To further reduce friction between the articulating surfaces of the bones, the knee joint is lined by a synovial membrane that produces a thick clear fluid called synovial fluid. This fluid lubricates and nourishes the cartilage and bones inside the joint capsule.
Within the knee joint, between the femur and tibia, are two C-shaped cartilaginous structures called menisci. Menisci function to provide stability to the knee by spreading the weight of the upper body across the whole surface of the tibial plateau. The menisci help in load-bearing i.e. it prevents the weight from concentrating onto a small area, which could damage the articular cartilage. The menisci also act as a cushion between the femur and tibia by absorbing the shock produced by activities such as walking, running and jumping.
Ligaments of the Knee
Ligaments are tough bands of tissue that connect one bone to another bone. The ligaments of the knee stabilize the knee joint. There are two important groups of ligaments that hold the bones of the knee joint together, collateral and cruciate ligaments.
Collateral ligaments are present on either side of the knee. They prevent the knee from moving too far during side to side motion. The collateral ligament on the inside is called the medial collateral ligament (MCL) and the collateral ligament on the outside is called the lateral collateral ligament (LCL).
Cruciate ligaments, present inside the knee joint, control the back-and-forth motion of the knee. The cruciate ligament in the front of the knee is called anterior cruciate ligament (ACL) and the cruciate ligament in the back of the knee is called posterior cruciate ligament (PCL).
Muscles of the Knee
There are two major muscles in the knee - the quadriceps and the hamstrings, which enable movement of the knee joint. The quadriceps muscles are located in front of the thigh. When the quadriceps muscles contract, the knee straightens. The hamstrings are located at the back of the thigh. When the hamstring muscles contract, the knee bends.
Tendons of the Knee
A tendon is a tissue that attaches a muscle to a bone. The quadriceps muscles of the knee meet just above the patella and attach to it through a tendon called the quadriceps tendon. The patella further attaches to the tibia through a tendon called the patella tendon. The quadriceps muscle, quadriceps tendon, and patellar tendon all work together to straighten the knee. Similarly, the hamstring muscles at the back of the leg are attached to the knee joint with the hamstring tendon.
Knee Conditions
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Knee PainKnee pain is a common condition affecting individuals of various age groups. It not only affects movement but also impacts your quality of life. An injury or disease of the knee joint or any structure surrounding the knee can result in knee pain.
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Knee Arthritis
The joint surface is covered by a smooth articular surface that allows pain-free movement in the joint. Arthritis is a general term covering numerous conditions where the joint surface or cartilage wears out. This surface can wear out for several reasons; often the definite cause is not known.
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Patellofemoral Instability
Patellofemoral instability means that the patella (kneecap) moves out of its normal pattern of alignment. This malalignment can damage the underlying soft structures such as muscles and ligaments that hold the knee in place.
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ACL Injuries
The ACL (anterior cruciate ligament) is one of the four major ligaments located within the knee joint. It connects the femur (thighbone) to the tibia (shinbone). It plays a key role in holding the two bones within the knee and keeping the joint stable while your knee moves back and forth.
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Patellar Dislocation
Patellar dislocation occurs when the patella moves out of the patellofemoral groove, (trochlea) onto the bony head of the femur. If the kneecap partially comes out of the groove, it is called subluxation; if the kneecap completely comes out, it is called dislocation (luxation).
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Cruciate Ligaments
The anterior cruciate ligament (ACL) is one of the major ligaments of the knee. It is located in the middle of the knee and runs from the femur (thighbone) to the tibia (shinbone).
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Meniscal Injuries
Meniscal tears are among the commonest injuries to the knee joint. It can occur at any age but are more common in athletes involved in contact sports. The meniscus has no direct blood supply and for that reason, when there is an injury to the meniscus, healing is difficult.
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Knee Bursitis
Coming Soon
Knee Treatments
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Diagnostic Imaging
MRI is a computer-based imaging technique that creates a magnetic field inside your body to obtain images. The images of nerves or soft tissue inside your body are obtained.
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Patellofemoral Realignment
Patellofemoral realignment is a surgical procedure performed to treat symptomatic patellofemoral instability that does not respond to nonsurgical treatment measures.
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Medial Patellofemoral Ligament Reconstruction
The medial patellofemoral ligament is a band of tissue that extends from the femoral medial epicondyle to the superior aspect of the patella. It is a major ligament that stabilizes the patella and helps in preventing patellar subluxation (partial dislocation) or dislocation.
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Physiotherapy
Physical therapy (PT) is an exercise program that helps you improve movement, relieve pain, encourage blood flow for faster healing, and restore your physical function and fitness level. The main goal of physical therapy is to make your daily activities such as walking, getting in and out of bed, or climbing stairs easier.
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Cortisone Injection
Cortisone injections are recommended for injuries that cause pain and inflammation, and those that don’t require surgical treatment.
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Meniscus Surgery
Meniscal surgery is a surgical procedure employed for the treatment of torn or damaged meniscal tissues in the knee. It is mostly performed as a minimally invasive keyhole procedure.
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Cartilage Repair
Cartilage cell transplantation is a technique of transplanting healthy cartilage cells to replace damaged cartilage cells. These procedures are recommended for young individuals with a single articular defect. It is usually performed on the knee joint but may also be used to treat the shoulder and ankle joints.
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Arthroscopy of the Knee
Knee arthroscopy is a common surgical procedure performed using an arthroscope, a viewing instrument, to diagnose or treat a knee problem. It is a relatively safe procedure and you will usually be discharged from the hospital on the same day of surgery.
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Knee Joint Replacement
Total knee replacement is a very successful surgical treatment for knee arthritis. Over the years, minimally invasive knee replacement surgical techniques have been developed to lessen tissue trauma and improve patient outcomes.
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Partial Knee Replacement
Unicompartmental knee replacement is a minimally invasive surgery in which only the damaged compartment of the knee is replaced with an implant. It is also called a partial knee replacement.
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Revision Knee Replacement Surgery
Revision knee replacement surgery involves replacing a part or all your previous knee prosthesis with a new prosthesis. Although total knee replacement surgery is successful, sometimes the procedure can fail due to various reasons and may require a revision surgery.
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ACL Reconstruction
ACL (anterior cruciate ligament) reconstruction is a commonly performed surgical procedure. With recent advances in arthroscopic surgery, it can now be performed with minimal incision and low complication rates.
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Robotic Knee Replacement Surgery
Robotic-assisted knee replacement surgery is an alternative to the conventional knee replacement procedure. It is performed using robotic-arm technology that allows your surgeon to precisely perform the surgery through a smaller incision as compared to traditional surgery..
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Patellofemoral surgery
Traditionally, arthritis in only one compartment of the knee is treated by partial knee replacement surgery. Patellofemoral knee replacement is a minimally invasive surgical option performed in the patellofemoral compartment only, preserving the knee parts not damaged by arthritis as well as the stabilizing anterior and posterior cruciate ligaments (ACL and PCL).
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Clinical Examination
Coming Soon