What causes stiffness of the knee?

A stiff knee is a common problem among older people and those who are not physically fit. It can be caused by muscular or poor flexibility in a person’s legs. Arthritis and injuries are also common causes of the stiffness of the knee.

Cause of knee stiffness

Menisci injury

Menisci comprise of two C-shaped cartilages that sit on the knee joint. The role of the two pieces of cartilage is to act as a shock absorber between several bones that make up the knee joint.

You can damage or injure a meniscus by suddenly twisting or moving your knee. This commonly happens during athletics or any other form of sport. Sportsmen and women often wear knee protective gear in order to avoid such injuries.

Menisci also become more vulnerable as you grow older because of degeneration. As they degrade, the chances of tearing increases.

When your menisci tears or get damaged, you are likely to experience a “pop”. This is the point when the stiffness of the knee problem sets in – as per the American Academy of Orthopaedic Surgeons.

Although you will still be able to walk normally, you will experience the following signs:

• Swelling
• Pain
• Loosing of full range motion
• Locking knee


Arthrofibrosis is another major cause of knee stiffness. It happens when more than enough scar tissue is formed within the knee joint. This condition is common especially after knee surgery such as a cruciate ligament surgery or knee replacement.

Some common signs of arthrofibrosis include:

• Warmth and swelling around the knee
• Walking while your knee is bent
• Worsening knee pain

Injury to ligaments

Ligaments fiber bands that join bones. Ligaments running over the knee joint connect the femur, thigh bone to the tibia, or lower leg.

In case you are injured during a sport or any other strenuous activity, Orthopaedics at Plano TX will be able to examine which tissues and ligaments have been affected and find the best solution to the problem.

How will you know that your ligaments have been raptured or torn? Below are some of the signs:

• Instability of the knee
• A lot of pain at the knee joint
• Unusual swelling at the knee joint


There are three main types of arthritis that cause stiffness of the knee. Let us take a look at each one of them in detail.

Rheumatoid arthritis

Rheumatoid arthritis is brought about by an autoimmune condition that makes the body to attack its own tissues. The condition generally affects both your knees.
If you have rheumatoid arthritis, you are likely to experience synovial membrane swelling that basically causes stiffness in the knee.


This occurs due to the wear and tear of cartilage between the bones. You will start to experience stiffness at the knee because of worn-out cartilage that causes bones to rub against each other.

Post-traumatic arthritis (PTA)

Post-traumatic arthritis happens several years after you had a knee injury. Below are the signs of PTA:

• Swelling of the knee
• Feeling weak at the knee
• Worsening pain during wet weather

In general, knee stiffness can affect almost everybody. The good thing is that Plano TX and other medical facilities have doctors than specialize in Knee injuries. It is important to visit them as soon as you realize the symptoms.

Call POSMC today!

To schedule an appointment with one our specialists, contact our scheduling department at 972-250-5700 or request an appointment online.

POSMC is a full-service medical facility specializing in the evaluation and treatment of orthopedic injuries. The practice is led by a group of 12 board-certified and fellowship-trained orthopedic surgeons and a physical medicine and rehabilitation physician. Contact us today!