What You Need to Know About Knee Pain? What If It’s Not Arthritis?

Joseph R. Anticaglia MD
Medical Advisory Board

People of all ages have experienced knee pain that varies from being a nuisance to incapacitating agony. We need healthy knees to walk, run, stand or jump. When injury or disease triggers knee pain, it’s critical to get pain relief, the right diagnosis and treatment as well as information on how to prevent future problems. To help understand knee pain or knee problems, it’s useful to be familiar with the knee joint

The knee joint (KJ) is a load-bearing joint. With every step you take, it is battered by the force of two or three times your body weight. If you’re healthy, injury-free and not obese or overweight, it is built to withstand millions steps you take throughout a lifetime without causing you pain or knee problems.

Anatomy Snapshot

The knee joint has been compared to a door hinge that moves in a forward-backward direction. In order to straighten and bend the legs, the KJ needs to be stable and flexible.

The KJ is made up of bones that are held together by soft tissues, namely, muscles, tendons, ligaments and cartilage which act as a cushion between the bones. It is the soft tissues of the knee joint that give the knee stability and flexibility. People of all ages have experienced knee pain that varies from being a nuisance to incapacitating agony. We need healthy knees to walk, run, stand or jump. When injury or disease triggers knee pain, it’s critical to get pain relief, the right diagnosis and treatment as well as information on how to prevent future problems. To help understand knee pain or knee problems, it’s useful to be familiar with the knee joint.

Source Wiki commons

There are three main Bones that are part of the knee joint: the thigh bone or femur, shin bone or tibia and the kneecap or patella.

Cartilage is a smooth, rubbery-like tissue that covers the lower end of the femur and the upper end of the tibia. Another cartilage, between the two long bones, sits on top of the tibia, the meniscus. This C shaped cartilage acts as a shock absorber and can be damage as the result of arthritis, injury or chronic overuse.

There are two main muscle groups: The quadriceps muscles straighten the legs and are found on the front of the thighs. The hamstring muscles bend the leg are found on the back of the thighs. You might have notice athletes who hobble to a point of not moving, holding the back of the thigh after they “pulled their hamstrings.”

Tendons are fibrous (non-elastic) tissues that connect muscles to bones. Ligaments are elastic bands of tissues that connect bone to bone in a joint; they protect and stabilize the knee joint. Some ligaments

prevent the thigh bone (femur) from sliding side to side. Other ligaments keep the thigh bone (femur) in alignment with the shin bone (tibia).

Disease or injury to any of the above structures can destabilize the knee joint and trigger knee pain and other symptoms as noted below.

Symptoms

Knee problems can be caused by arthritis, injury or repeated stress on the knee joints (running, being obese-overweight and weightlifting). Symptoms depend on what caused the knee problem and most of the time people have complaints concerning:

  • Knee pain
  • Difficulty walking
  • Stiffness-inability to bend or straighten the leg
  • Feeling off-balanced
  • Swelling, redness, warmth and pain to the touch
  • Crunching or popping sounds

Christina, a 47 year old woman, left her apartment and went down the six steps to the side walk as she has done for years. This time, after taking the first step on the pavement, the right knee “locked” and she fell to the ground.

The orthopedist diagnosed the problem as a torn cartilage in the right knee and suggested exercises and physical therapy. Eventually, the cartilage wore down and bone was rubbing against bone. She had difficulty walking and the knee pain became more intense. She finally agreed to a total knee replacement procedure of the right knee and was delighted with the outcome of the surgery.

Examples of Problems Causing Knee Pain

Arthritis

Osteoarthritis is the most common type of arthritis and it’s due to the wear and tear of joint cartilage. This can result in bone rubbing on bone. The pain seems to worsen as you move about during the day. Walking up and down stairs might cause pain behind the kneecap.

Rheumatoid arthritis is an autoimmune disease whose pain can vary in severity. Often the pain is worse in the morning and becomes less intense as you move about later in the day. The knee can be painfully red, swollen, warm and stiff.

Gout is the most common type of inflammatory arthritis causing attacks of severe pain and swelling in your joints. It occurs when there’s a build-up of uric crystals in the knee joint. It especially affects men and more often than not the big toe.

Septic Arthritis occurs when the knee joint becomes infected causing pain, swelling and redness.

Non-Arthritic Causes

Torn Cartilage A blow to the knee can tear the meniscus, the shock absorber cartilage between the two long bones of the knee joint. Symptoms include swelling, difficulty walking and at times a clicking sound in the knee. Pain on the inside or outside of the knee might indicate a torn meniscus. Sometimes the knee joint “locks up.”

Sprained or torn ligament can be caused by jumping and landing awkwardly or by a blow to the knee. Pain on the inside of the knee can be due to injury to the medial collateral ligament, pain on the outside of the knee might be due to injury the lateral collateral ligament. People may tell their doctor that they “heard a popping sound and the knee buckled sideways.” Other ligaments, the ACL or PCL (see below) can suffer knee joint injury.

Tendonitis is an inflammation of the tendon, the tissues that connect bone to muscle. People may have difficulty bending or stretching the knee and might experience pain to touch over the involved area.

Pain above the kneecap might mean quadriceps tendonitis. Pain below the kneecap often indicates patella tendonitis. Gymnasts (jumper’s knee), long distance runners are at greater risk to develop tendonitis. Other causes include: Baker’s cyst, bursitis and stress fractures.

Diagnosis

Doctors make the diagnosis, in addition to the medical history and physical examination, by utilizing tests such as x-rays, CAT scans, MRI, biopsy and arthroscopy-a procedure done to view your knee joint.

Treatment

Treatment of knee problems varies depending on the type of injury or condition. Many use the acronym ‘RICE’ as a reminder for the treatment of mild knee pain and problems.

  • Rest Stop and take a break from any activity that causes knee pain.
  • Ice Apply an ice pack to reduce pain and swelling.
  • Compression Wrap the injured area, not too tightly, to reduce swelling.
  • Elevation Raise the injured or sore area above the level of your heart to reduce swelling.
  • For more severe pain medications and/or surgery may be indicated.

For serious pain, go to the emergency room or a visit your physician to diagnose the reason for your pain. For mild knee pain or problems that lasts a week or two, it’s advisable to contact your physician. It’s worth noting, there are preventive steps you can take to reduce the pain and frequency of these episodes.

The knee is an essential part of our daily life. Arthritis, injuries and repeated stress on the knees are common causes of knee problems. When you have serious pain with serious symptoms or mild pain that doesn’t seem to go away, seek a health professional to get the answers to the problem.

Your physician will conduct the necessary examination and order imaging studies to sort out the reason for the pain. He or she may prescribe medications to reduce pain and swelling, recommend physical therapy to strengthen muscles, suggest the use of a knee brace, administer cortisone injection or advise surgery.

References

  1. Darryl D. D’Lima, et al; Knee joint forces: prediction, measurement, and significance; Proc Inst Mech Eng H. Feb 11; 2013
  2. Chinmay Gupte and Jean-Pierre St Mart; The acute swollen knee: diagnosis and management; J R Soc Med. Jul, 2013
  3. NIH, NIAMS; Knee Problems; March 30, 2016

Glossary

  • ACL Anterior Cruciate Ligament
  • PCL Posterior Cruciate Ligament

This article is intended solely as a learning experience. Please consult your physician for diagnostic and treatment options.