What causes a stiff knee?

A stiff knee is most commonly caused by an injury to the knee or by an inflammatory process, such as arthritis in the knee joint.

Traumatic causes of a stiff knee

Stiff knee may be caused by injuries to the joint or surrounding tissues including:

  • Fracture of any of the bones of the knee
  • Sprains and strains
  • Tearing or stretching of the ligaments
  • Tendinitis
  • Tendon rupture
  • Torn ligament or meniscus (cartilage)

Inflammatory causes of a stiff knee

A stiff knee can also be caused by conditions that lead to inflammation in or around the knee joint including:

  • Ankylosing spondylitis (inflammation of joints between the vertebrae of the spine)
  • Bursitis (inflammation of a bursa sac that cushions a joint)
  • Gout (type of arthritis caused by a buildup of uric acid in the joints) and pseudogout
  • Osteoarthritis
  • Psoriatic arthritis (arthritis associated with psoriasis of the skin)
  • Rheumatoid arthritis (chronic autoimmune disease characterized by joint inflammation)
  • Systemic lupus erythematosus (disorder in which the body attacks its own healthy cells and tissues)

Serious or life-threatening causes of a stiff knee

Rarely, a stiff knee may be a symptom of a serious or life-threatening condition that should be immediately evaluated in an emergency setting. These include:

  • Bone tumors
  • Osteomyelitis (bone infection)
  • Septic arthritis (infectious arthritis)

Questions for diagnosing the cause of a stiff knee

To diagnose your condition, your doctor or licensed health care practitioner will ask you several questions related to your stiff knee including:

  • How long have you felt stiffness in your knee joint?
  • Have you injured your knee?
  • Do you have any symptoms in other joints?
  • Does anything relieve or worsen the stiffness?
  • Do you participate in sports activities?

What are the potential complications of a stiff knee?

Complications of untreated knee symptoms, including stiff knee, can be serious. Because a stiff knee can be due to serious diseases, failure to seek treatment can result in complications and permanent damage. Once the underlying cause is diagnosed, it is important for you to follow the treatment plan that you and your health care professional design specifically for you to reduce the risk of potential complications including:

  • Absenteeism from work or school
  • Decreased athletic performance
  • Disability
  • Joint deformity and destruction
  • Nerve problems that cause pain, numbness or tingling
  • Permanent or chronic pain


Knee problems. FamilyDoctor.org. http://familydoctor.org/online/famdocen/home/tools/symptom/542.html. Accessed May 11, 2011.

Knee problems. National Institute of Arthritis and Musculoskeletal and Skin Diseases. http://www.niams.nih.gov/Health_Info/Knee_Problems/default.asp. Accessed May 11, 2011.


What is a stiff knee?

A stiff knee occurs when you have difficulty moving the knee joint due to injury to or inflammation of the joint. Anything that leads to restricted movement of the knee joint may be considered to cause stiffness of the knee.... Read more about stiff kneeintroduction


What other symptoms might occur with a stiff knee?

Stiff knee may accompany other symptoms, which vary depending on the underlying disease, disorder or condition. Conditions that cause stiff knee may also lead to symptoms in other body systems.... Read more about stiff kneesymptoms

Medical Reviewer: All content has been reviewed by board-certified physicians under the direction of Rich Klasco, M.D., FACEP. Last Annual Review Date: May 2, 2011 Copyright: © Copyright 2011 Health Grades, Inc. All rights reserved. May not be reproduced or reprinted without permission from Health Grades, Inc. Use of this information is governed by the HealthGrades User Agreement.

This Article is Filed Under: Bones, Joints and Muscles

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