The knee joint, made up of bone, cartilage, ligaments and fluid, is the largest joint of the body. Bones, cartilage, ligaments, and tendons work together to form your knee joint and allow you to bend your leg. As the largest joint in our bodies — the one that flexes 5 to 10 thousand times a day — it is not surprising that the knee is one of the most injured and most easily injured joints. 

Knee problems can interfere with many things, from participation in sports to simply getting up from a chair and walking. This can have a big impact on your life. Because of all the moving parts on the knee and the sensitive nature of the joint, it is very prone to multiple types of injuries.

Anatomy of the Knee

Joints are the areas where 2 or more bones meet. Most joints are mobile, allowing the bones to move. The knee is basically 2 long leg bones held together by muscles, ligaments, and tendons. Each bone end is covered with a layer of cartilage that absorbs shock and protects the knee. 

There are 2 groups of muscles involved in the knee, including the quadriceps muscles (located on the front of the thighs), which straighten the legs, and the hamstring muscles (located on the back of the thighs), which bend the leg at the knee. 

The knee consists of the following: 

  • Femur: Thighbone or upper leg bone
  • Tibia: Shin bone or larger bone of the lower leg
  • Patella: The kneecap
  • Cartilage: Tissue that covers the surface of a bone at a joint. Cartilage helps reduce the friction of movement within a joint
  • Synovial membrane: Specialized connective tissue that lines the inner surface of capsules of synovial joints and tendon sheath
  • Ligament: Tough, elastic connective tissue that surrounds the joint to give support and limits the joint’s movement
  • Tendon: Tough connective tissue that connects muscles to bones and helps to control movement of the joint
  • Meniscus: C-shaped piece of tough, rubbery cartilage that acts as a shock absorber between your shinbone and thighbone

Common Knee Injuries


Fractures in the knee in younger people can be caused by contact sports, accidents, or falls. In older people, it can be due to arthritis or osteoporosis. Any of the bones in or around the knee can be fractured. The most commonly broken bone in the joint is the patella or kneecap.

Your patella protects your knee joints from injuries or further damage. When you fall or collide with an object or a person, your kneecap makes first contact and shields the different parts within your knee joint. This makes the kneecap susceptible to fractures. Knee fractures are typically very serious. The knee must be immobilized to allow the bone to heal or sometimes needs surgery for repair.


Dislocating the knee happens when the bones of the knee are out of their proper placement and alignment. This can happen when there is a large impact to the knee, such as a fall, a collision or a car accident. Dislocating your knee will be incredibly painful and almost always requires emergency treatment. In certain rare situations, the knee will correct itself. It will feel a little sore, but will function normally. Ongoing treatment from a dislocation will almost always require physical therapy to regain the full range of motion and stability in your knee. 

Ligament Injuries

The anterior cruciate ligament (ACL) runs diagonally down the front of the knee, providing critical stability to the joint. Athletes who participate in contact sports such as football or soccer often injure their ACLs. However, contact sports are not the only cause of this injury. Ligament injuries occur when the knee is overextended, or moved in a way it should not naturally move and the ligaments are unable to support the movement. Since the ligaments serve to keep the knee in place, if they are forced too much, they aren’t able to do their job and they can stretch or tear. Injuries to the ACL can be serious and require surgery.

Meniscus Tears

When people refer to torn cartilage in the knee, they are probably talking about a meniscal tear. The menisci are two rubbery wedges of cartilage between the thighbone and shinbone. These pieces of cartilage can tear suddenly during sporting activities. They may also tear slowly due to aging. With a sudden meniscus tear, a pop may be heard or felt in the knee. After the initial injury, pain, swelling, and tightness may increase over the next few days.

Meniscus tears occur frequently during sports where jumping or twisting is involved, such as volleyball. Meniscus tears also are common in sports such as football or soccer, where athletes change direction quickly while running. Any type of knee twisting, cutting or pivoting can result in a torn meniscus. Sometimes the meniscus also tears from wearing out over time. When the meniscus tears due to the natural aging process, it is referred to as a degenerative meniscus tear.

Tendon Tears

Tendons are soft tissues that connect the muscles to the bones. In the knee, a common tendon to be injured is the patellar. Tendon tears can happen to anyone, but are especially common in middle-aged people who are running or engaging in jumping sports and other activities. Landing awkwardly after coming down from a jump is a common way to injure the tendon, as the tendon is unable to support the overextension. Falls can also cause a stretched tendon due to the direct force to the front of the knee.

 Worn Cartilage 

Cartilage can wear out from use over the years and lead to osteoarthritis. It differs from other knee injuries, because this wear-and-tear occurs over a long time not from an immediate traumatic accident. Eventually, it may require a knee joint replacement.

Symptoms of a Knee Injury

The main symptom of patellar tendonitis is pain, swelling and tenderness just below the kneecap. You may also have difficulty with the joint moving. It may feel stiff, lock up, or feel like it is catching as you bend and straighten your leg. The pain usually starts after exercise, and continued exercise will likely increase the discomfort. Jumping, running, and landing are likely to make the pain worse.

If you hear your knee pop and then give out at the time of impact, it is definitely a cause for concern. This popping sound could be the sound of something tearing. You may begin to notice weakness in the knee, particularly during exercises that put pressure on this part of the body.  When the leg is straight, the area below the knee may feel tender when touched. The area around the knee can also feel tight or stiff, particularly first thing in the morning.

Treatment Options

If you are experiencing minor knee pain, you may find relief from self-care methods. Your provider may recommend following the RICE method—rest, ice, compression and elevation—to reduce inflammation. Physical therapy and bracing can also be beneficial. Speak with your provider or physical therapist to determine the treatment options that are best suited for you.

  • Physical Therapy

Physical therapy will involve a program of several weeks of specific stretches and exercises to restore function of your knee joint. In addition, the exercises will strengthen the muscles surrounding the joint. 

  • Pain Medication

At times symptoms may be severe enough to warrant taking medications. NSAIDs like ibuprofen or naproxen are the medications of choice to treat the inflammation of knee pain.

  • Steroid Injections

When oral medications are not enough, a corticosteroid injection, as well as an aspiration of joint fluid, may be needed to reduce symptoms. Corticosteroids are strong anti-inflammatory medications used to treat inflammatory pain associated mainly with arthritis.

  • Surgery

Ultimately, there are some knee problems that require surgical intervention. You may need surgery to treat your knee injury in certain cases to fully restore its function, when physical therapy and other methods have not proven successful. Some injuries cannot heal on their own, such as a completely torn ligament, and they’ll need to be operated on. Many knee surgeries can be minimally invasive and performed arthroscopically using miniature tools and small incisions. In other cases, your surgeon will need to make a larger incision to repair the injury. 

Call Ventura Orthopedics Today!

Do not ignore a nagging knee pain — it could be an injury that needs attention before it gets worse.

If you are experiencing pain associated with knee injuries that need professional help, contact Ventura Orthopedics or to schedule an appointment with one of our hip replacement specialists, call us at 800-698-1280.

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