The knee is a complex hinge joint made up of 2 bones, the thighbone (femur) and the shinbone (tibia). Another smaller bone that runs along the side of the tibia, called the fibula, and the kneecap (patella) are also bones of the knee joint. All are surrounded by connective tissue that stabilize the joint and contribute to the function of the knee, tendons, ligaments, and muscles.
Articulating surfaces between the bones are covered with a white, slippery layer called articular cartilage. The cartilage provides a smooth surface that facilitates easy movement. This is the tissue that degenerates in osteoarthritis. To further reduce friction between the articulating surfaces of the bones, the knee joint cavity is lined by a synovial membrane, which produces a thick, clear fluid called synovial fluid. This fluid lubricates and nourishes the cartilage and bones inside the joint capsule.
Ligaments are tough bands of tissue that connect one bone to another bone. The ligaments of the knee stabilize the knee joint. Two primary groups of ligaments hold the bones of the knee joint together: collateral ligaments and cruciate ligaments.
Platelet-rich plasma (PRP) therapy, dextrose prolotherapy, and biocellular prolotherapy using the patient's own stem cells stimulate accelerated re-growth of healthy tissues in the damaged area to stabilize and strengthen the joint. These therapies can effectively bridge the gap between medication treatment that can merely mask an injury and invasive surgery.
Common conditions of the knee include:
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. This condition most commonly affects the joints in hips, knees, hands, and spine. Rarely, the disease may affect the shoulders, wrists and feet.
Wearing of the cartilage covering the bone ends of a joint causes osteoarthritis. Being overweight, excessive strain over prolonged periods of time, previous fracture, growth abnormalities, joint diseases, injury, or deformity contribute to the development of osteoarthritis. Some people have congenital abnormalities of the joints that cause early degeneration leading to osteoarthritis.
Meniscus & cartilage wear and tears. The 2 wedge-shape cartilage pieces between the thighbone and the shinbone are called menisci. They stabilize the knee joint and act as "shock absorbers".
Meniscus tear is the most common knee injury in athletes, especially those involved in contact sports. A sudden bend or twist in the knee causes the meniscus to tear. Elderly people are more prone to degenerative meniscal tears as the cartilage wears out and weakens with age.
A torn meniscus causes pain, swelling, stiffness, and catching or locking in your knee that makes you unable to move your knee through its complete range of motion.
Ligament injury. These connective tissues are prone to injury during high impact and, sometimes, just normal activity.
Collateral ligaments are present on either side of the knee. They stabilize the knee in side-to-side motion. The collateral ligament on the inside knee is called the medial collateral ligament (MCL) and the collateral ligament on the outside is called the lateral collateral ligament (LCL).
Cruciate ligaments, located 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).
Damaged ligaments release substances that cause pain and shortening of the tissue around the joint. The scar tissue that forms is less elastic than normal tissue and gets worse the longer the knee is immobile. It is important to restore movement as soon as possible to encourage blood flow to the area and keep joint fluid from becoming thick and sticky.
Other common knee conditions include:
- Osgood-Schlatter disease
- Patellofemoral pain syndrome ("Runner's Knee")
- Patellar tracking Disorder
- Chondromalacia patella
- Jumper's knee
- Iliotibial (IT) band syndrome
For more information on treatments for knee conditions please visit Our Services page.