What to Know About Internal Derangements of the Knee

Medically Reviewed by Tyler Wheeler, MD on February 28, 2024
3 min read

Knee injuries are some of the most common and the most painful injuries. Internal derangement of the knee, or IDK, is a chronic mechanical condition that affects your knee joint. The term is used for several disorders, all involving the ligaments or cartilage in the knee.

There are many causes and treatments available for this condition. You’ll want to work with your doctor to find the best treatment for you.

Causes of internal derangement of the knee include:

  • Injury. Injuries that cause knee derangement include a tear in ligaments like the anterior cruciate ligament (ACL), a fracture, or a torn meniscus. Bursitis and tendonitis can also result from injury and contribute to IDK. 
  • Mechanical issues. Examples of these problems are dislocated kneecaps and loose body, a condition that occurs when a piece of bone or cartilage breaks off inside the knee and interferes with movement.
  • Arthritis. There are many different types of arthritis. Some of the most common are osteoarthritis and rheumatoid arthritis, and these contribute to knee problems. There’s also gout and pseudogout.

These problems are common in athletes, younger adults whose kneecaps don’t track properly, and older adults, who usually develop IDK due to arthritis.

Some common symptoms of IDK are:

  • Pain, especially when in motion
  • Swelling and stiffness in the joint
  • Redness
  • Warmth to the touch
  • Weakness or instability
  • Popping or crunching noises
  • An inability to straighten your leg completely

These symptoms may be ongoing, or they may come and go. You’ll want to contact your doctor immediately if you have:

  • An inability to put your full weight on the knee or a feeling that the knee's going to give out
  • Excessive swelling
  • An obvious deformity in your knee or leg
  • A fever along with redness, pain, and swelling
  • Severe pain due to an injury

To find the cause of your knee pain, your doctor may ask you a series of questions:

  • Where is the pain located?
  • When did the pain start?
  • Has there been any injury or trauma to that area?
  • What makes it better?
  • What makes it worse?
  • How severe is the pain?
  • Is the pain radiating or limited to one area?
  • Have you tried anything to treat the pain? Ex. medication or stretches
  • Has there been any previous diagnosis relating to this pain?

After your doctor has a clearer picture of the problem, they’ll examine your knee — checking for swelling, visible bruising, or heat. They may push on or pull your leg or knee to test the joint. They’ll also ask you to move your leg in different positions to check for its range of motion.

After your initial examination, your doctor may order imaging tests like an MRI or a CT scan. They'll review your scans, looking for tears or breakdowns in the cartilage or ligaments of your knee.

Once your doctor finds the source of the pain they can recommend a treatment plan. Some of the treatment options are:

  • Medications. Medications can include over-the-counter pain relievers like aspirin, ibuprofen (Advil or Excedrin), acetaminophen (Tylenol), or naproxen (Aleve). If these pain relievers don’t help, your doctor may prescribe a stronger or controlled substance for the pain.
  • Physical therapy. Having strong muscles around your knee will help with stability, so your doctor may recommend therapy or exercises to target the area. If you play sports, you may need exercises that help correct your movements to protect your knee. 
  • Injections. Your doctor may suggest injecting medications, like corticosteroids, into your knee. These injections should help with mobility and pain relief.
  • Surgery. There are several kinds of surgery for IDK including complete knee replacement. Your doctor will recommend the best-suited procedure if and when you need it. 

There are some things you can do to reduce your risk of injuring your knee:

  • Be in top form for your sport. If you’re an athlete or play sports regularly, make sure that your technique and movements are correct. Not using proper form increases your risk of injury.
  • Be smart about exercise. If you have chronic knee pain or osteoarthritis, consider changing the types of exercise you engage in. Low impact exercises like swimming put less stress on your knees. It’s important to continue exercising to stay strong and keep your joints stable.
  • Maintain a healthy weight. Carrying extra weight puts stress on your joints, increasing your risks of injuries and osteoarthritis.