Introduction
What is the knee joint?
Of the 360 joints in the body, the knee is the largest and most complex. The intricate anatomical design allows the knee joint to withstand substantial amounts of internal and external stress every day. The knee joint can flex, extend, and twist side-to-side; however, this mobility can make the knee joint vulnerable to injury. Dr. Frank McCormick, orthopedic knee specialist serving Orlando, Palm Beach County, and surrounding Florida communities, has the knowledge and understanding of knee anatomy, as well as substantial training and experience in treating common knee injuries.
What are the important structures of the knee joint?
The bones, cartilage, ligaments, and tendons are the four major components of the knee joint. Other tissues, such as muscles and bursae, are also important for the strength and mobility of the knee joint.
Bones
The knee joint is formed by the connection of the femur (thigh bone), patella (kneecap), and tibia (shin bone). The fibula, a smaller bone alongside the tibia, provides an attachment point for an extra-articular ligament.
Cartilage
The knee joint houses articular and meniscus cartilage. Articular cartilage is a white connective tissue that envelops the lower end of the femur, the upper end of the tibia, and the posterior (back) side of the patella. This shiny and slippery cartilage protects the bones with joint movement. There are two crescent-shaped discs of meniscus cartilage found between the femur and tibia. Different from articular cartilage, this tough and rubbery tissue acts as a shock absorber to reduce friction from movement between the femur and tibia.
Ligaments
Within the knee joint are four major ligaments categorized as cruciate and collateral ligaments. Similar to strong ropes, these elastic tissue bands connect and maintain bone alignment to stabilize the knee joint.
Cruciate Ligaments. The anterior cruciate ligament (ACL) and the posterior cruciate ligament (PCL) form an “X” within the knee joint. These ligaments are important for limiting forward and backward movement of the tibia in relation to the femur.
Collateral Ligaments. These extra-articular ligaments are located outside of the knee joint and protect the knee joint from unusual twisting movements. The medial collateral ligament (MCL) connects the inner femur and tibia and prevents the knee joint from collapsing inward. The lateral collateral ligament (LCL), also called the fibular collateral ligament (FCL), connects the outer femur to the fibular head and prevents the knee from collapsing outward.
Tendons
Muscles are connected to bones by tough bands of soft tissue known as tendons. The largest tendon (quadriceps tendon) associated with the knee joint connects the quadriceps femoris, the four muscles of the anterior thigh, to the patella. The patellar tendon functions more like a ligament as it connects the patella to the tibia. These two tendons work together with the quadriceps muscles to straighten and bend the knee.
Muscles
The quadriceps femoris is the group of four muscles of the anterior thigh that are important for straightening the knee joint. The hamstrings, opposite the quadriceps, are the group of three muscles of the posterior thigh that are important for bending the knee. The gluteus minimus and gluteus maximus muscles of the buttocks are important in positioning the knee, but these muscles are even more essential to the function of the patellofemoral joint located behind the kneecap.
What are the common knee joint injuries and conditions treated by Dr. McCormick?
The intricacies and multiple structures of the knee joint make this joint susceptible to injury. Damage to the knee joint can result from sports-related activities, chronic joint use, a degenerative condition, or even a simple accident. The following are knee joint injuries and conditions addressed by Dr. McCormick:
- Knee Arthritis
- Knee Malalignment (Valgus and Varus)
- Anterior Crucial
- Ligament (ACL) Injury Posterior Cruciate
- Ligament (PCL) Injury
- Medial Collateral
- Ligament (MCL) Injury
- Medial Patellofemoral
- Ligament (MPFL) Injury
- Meniscus Tears of the Knee
- Cartilage Injuries of the Knee
- Meniscal Deficiency
- Patella Chondromalacia (Runner’s Knee)
- Patella Dislocation
- Patellar Tendon Injury
For more information on meniscus tears of the knee, or the excellent treatment options available, please contact the office of Frank McCormick, MD, orthopedic knee specialist serving Orlando, West Palm Beach County, and surrounding Florida communities.
