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 Pain
Knee 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. A precise diagnosis of the underlying cause is important to develop an appropriate treatment plan.

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.

Knee Osteoarthritis
Osteoarthritis also called degenerative joint disease, is the most common form of arthritis. It occurs most often in older people. This disease affects the tissue covering the ends of bones in a joint (cartilage).In a person with osteoarthritis, the cartilage becomes damaged and worn out causing pain, swelling, stiffness and restricted movement in the affected joint.

Patellofemoral Arthritis
Patellofemoral arthritis is an inflammatory condition characterized by loss of the smooth cartilage between the kneecap (patella) and the underlying femoral (thigh) bone in the knee joint. When the articular cartilage wears out, the underlying bones rub against each other, causing pain, swelling, stiffness, and restricted movement.

Meniscal Injuries
Meniscal tears are one of the most common 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.

Periprosthetic Knee Infection
A very small percentage of patients (less than 1%) who undergo knee replacement may develop an infection around the knee joint. This infection is called a periprosthetic knee infection.

Painful or Failed Total Knee Replacement
Total knee replacement is a surgery employed to resurface knee joints damaged by arthritis, degeneration, or injury and replacing the damaged joints with a prosthesis (an artificial knee joint).

Robotic Assisted Knee Replacement
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.

ROSA Robotic Total Knee Replacement
ROSA® is a robotic surgical assistant developed by Zimmer Biomet that enables surgeons to carry out knee and hip replacement surgeries with greater precision. The ROSA® robotic system utilizes real-time information and assists surgeons with precise placement of the implants based on a person’s unique anatomy.

Total Knee Replacement
Total knee replacement, also called total knee arthroplasty, is a surgical procedure in which the worn out or damaged surfaces of the knee joint are removed and replaced with an artificial prosthesis.

Outpatient Total Knee Replacement
Total knee replacement is the surgical treatment for knee arthritis, where the damaged knee is removed and replaced with an artificial knee implant. Traditionally performed as an inpatient procedure, total knee replacement surgery is now being conducted on an outpatient basis, allowing you to go home on the same day of the surgery.

Cementless Total Knee Arthroplasty
Cementless total knee arthroplasty uses a special kind of knee implant, also called press-fit implant, that is fixed to the bone without the use of bone cement. The cementless knee implants have a porous surface with specific holes and are attached to the bones with screws. As time progresses, the bone cells grow into the implant.

Unicompartmental/Partial Knee Replacement
Unicompartmental/Partial Knee Replacement is a minimally invasive surgical procedure in which the worn out or damaged surfaces of the hip joint are removed and replaced with artificial joint components made of metal, ceramic, or plastic. It is also referred to as muscle sparing surgery because key muscles and tendons are left intact while accessing the hip joint, enabling a quicker return to normal activity.

Unicondylar Knee Replacement
Unicompartmental knee replacement or unicondylar 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.

Computer Navigation for Total Knee Replacement
Computer navigation provides your surgeon with real-time 3-D images of your mapped knee and the surgical instruments during surgery. The data for the images is provided by infrared sensors fixed to the bones of the knee and surgical instruments. Their position is tracked by an infrared camera placed above the surgical table, which is connected to a computer.

Knee Replacement with OrthAlign Technology
Exercising the muscles that surround and support the knee help restore range of motion and joint strength after knee replacement surgery. To ensure a positive surgical outcome after knee replacement, you are recommended to perform physical therapy exercises 2-3 times a day and walk for 30 minutes every day.

Complex Total Knee Replacement
Total knee replacement, also called total knee arthroplasty, is a surgical treatment for painful arthritis of the knee in which the worn-out or damaged surfaces of the knee joint are removed and replaced with an artificial prosthesis.

Custom Knee Replacement
Custom Knee Replacement is an advanced surgical procedure in which the damaged knee joint is replaced by a customized implant, specifically designed to match the unique size and shape of each patient’s knee.

Rapid Recovery Knee Replacement
Rapid recovery knee replacement, also known as an outpatient knee replacement, is an innovative procedure that is performed to replace a damaged knee joint with a prosthesis using minimally invasive techniques and surgical instruments that minimize post-operative pain and discomfort and promote faster recovery for patients.

Short-Stay and Fast-Track Knee Replacement
Short-stay and fast-track knee replacement is a minimally invasive surgical procedure in which the worn-out or damaged surfaces of the knee joint are removed and replaced with prostheses. It is a multidisciplinary approach for knee treatment in which patients are mobilized as early as possible to achieve a faster and better recovery without compromising quality.

Revision Knee Replacement
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 second revision surgery.

Persona Revision Knee System
The Persona® Revision knee system is an advanced total knee system designed specifically for the purpose of complex primary or revision knee replacement.

Correction of a Loose Knee Replacement
Knee replacement is a surgery employed to resurface a knee joint damaged by arthritis, wear and tear, or injury and replacing the damaged joint with a prosthesis (an artificial knee joint) to resolve a painful knee condition and loss of motion.

Correction of a Painful Knee Replacement
Knee replacement is a surgery employed to resurface a knee joint damaged by arthritis, wear and tear, or injury and replacing the damaged joint with a prosthesis (an artificial knee joint) to resolve a painful knee condition and loss of motion.

Nonsurgical Knee Treatments
The knee is a complex joint that consists of bone, cartilage, ligaments, and tendons that make joint movements easy and at the same time it is more susceptible to various kinds of injuries. Knee problems may arise if any of these structures get injured by overuse or suddenly during sports activities.

Intraarticular Knee Injection
Knee pain and stiffness can be disabling and difficult to treat. It can limit an individual’s lifestyle and negatively impact body image and emotional well-being.

Viscosupplementation
Viscosupplementation refers to the injection of a hyaluronan preparation into the joint. Hyaluronan is a natural substance present in the joint fluid that assists in lubrication. It allows the smooth movement of the cartilage-covered articulating surfaces of the joint.

Physical Therapy for Knee
Physical therapy is an exercise program that helps you to improve movement, relieve pain, encourage blood flow for faster healing, and restore your physical function and fitness level. It can be prescribed as an individual treatment program or combined with other treatments.

Pre-op and Post-op Knee Guidelines
Planning for your hip or knee surgery prepares you for the operation and helps to ensure a smooth surgery and easier recovery. Here are certain pre-operative and post-operative guidelines which will help you prepare for hip or knee surgery.

Knee Replacement Exercise Guide
Exercising the muscles that surround and support the knee help restore range of motion and joint strength after knee replacement surgery. To ensure a positive surgical outcome after knee replacement, you are recommended to perform physical therapy exercises 2-3 times a day and walk for 30 minutes every day.

Physical Examination of the Knee
A complete physical examination of the knee is performed when you present to your doctor with a knee complaint. Both of your knees are examined and the results of the injured knee are compared to those of the healthy knee.