Osteoarthritis (OA)

Study guide:

Definition:

  • Osteoarthritis is a degenerative joint disease that results from breakdown of joint cartilage and underlying bone.

  • The most common form of arthritis, often affects joints of the hands, knees, hips and spine.

  • The pain and stiffness may become severe enough to affect daily activities.

Epidemiology:

  • In Saudi Arabia:

    • One study showed that Radiographic OA was seen in (53.3%) of adult males and in (60.9%) of adult females.

  • Worldwide:

    • In the United States osteoarthritis affects more than 20 million individuals.

    • Approximately 80-90% of individuals older than 65 years have evidence of radiographic primary osteoarthritis.

    • In individuals older than 55 years, the prevalence of osteoarthritis is higher among women.

Risk factors:

  1. Aging (Common after 60): Most Important Risk Factor!

  2. Gender: Women are more likely to develop osteoarthritis.

  3. Congenital disorders of joints.

  4. Diabetes

  5. Inflammatory diseases such as Perthes' disease and chronic forms of arthritis (e.g., costochondritis, gout, and rheumatoid  arthritis).

  6. Joint infection

  7. Obesity

  8. Joint injuries

  9. Genetics

  10. Bone deformities

Etiology:

  • Geneticfactors:

    • Rare defect in collagen production that makes up cartilage (OA as early as age 20).

  • Environmental factors:

    • Primary OA: idiopathic.

    • Secondary OA:

      • Pre-existing joint damage: e.g. Gout.

      • Metabolic disease: e.g. Acromegaly. 

      • Systemic disease: e.g. sickle cell disease.

Pathophysiology:

  • Onset:

    • Collagen matrix disorganization and#proteoglycan content within cartilage.

    • Breakdown of collagen fibers -> ^ water content (due to overall loss of proteoglycans

      as the collagen was lost).

  • As osteoarthritis progresses:

    • ​Proteoglycans level drops  -> the cartilage soften and lose compromising joint surface integrity.

  • Over time:

    • Loss of cartilage -> loss of joint space.

    • Weight-bearing joints have greater joint-space narrowing.

    • ​Articular cartilage damage and loss: cartilage damage results in exposure of subchondral joint, loss of joint space, and change in joint stress.

    • Eburnation: increased stress on the exposed bone will result in increase in its density. 

    • Osteophytes: bony outgrowths result from remolding of the bone due to increased stress. This could be seen on the DIP (Heberden nodes) or PIP (Bouchard nodes).

Damaged cartilage could be found in the joint space as small fragments known as Joint Mice.

Clinical Presentation:

  • Symptoms:

    • Joint pain that’s worse with movement

    • Morning joint stiffness

    • Functional limitation

  • Signs:

    • Crepitus

    • Restricted movement

    • Bony enlargement

    • Joint effusion and variable levels of inflammation

    • Bony instability and muscle wasting

Diagnosis (made based on clinical and radiographic findings):

  • History:

    • Palpable bony joint enlargement

    • Morning stiffness

    • Pain

  • Physical Examination:

    • Reduced range of motion

    • Joint malalignment

    • Crepitus

    • No inflammatory signs

  • X-ray: Most accurate test. Helps to track the status of OA over time (image below). Findings: presence of osteophytes and joint space narrowing.

  • Other Tests: Usually normal in OA.

  • Aspiration of synovial fluid: to rule out other inflammatory arthropathies.

Management:

  • Lifestyle changes (Non-pharmacological):

    • Exercise.

    • Weight loss.

    • Use assistive devices.

    • Physical therapy

    • Appropriate footwear

  • Pharmacological treatment: (see table)

  • Surgery:

    • Arthroplasty: Joint replacement therapy

    • Osteotomy: if the patient is not suitable for arthroplasty, this operation helps realigning

      the weight so it’s no longer in the damaged part, by adding or removing a small section of the bone.

  • Follow up:

    • History: Address palpable bony joint enlargement, morning stiffness, and pain.

    • Physical Examination: Check for reduced range of motion and joint malalignment.

Complications:

  • Sleep disruption

  • Reduced quality of life

  • Reduced productivity

References:

  1. AA, Al-Arfaj. 'Prevalence Of Radiographic Knee Osteoarthritis In Saudi Arabia. - Pubmed - NCBI'. Ncbi.nlm.nih.gov. N.p., 2015. Web. 20 Nov. 2015.

  2. Al-Arfaj AS, et al. 'Knee Osteoarthritis In Al-Qaseem, Saudi Arabia. - Pubmed - NCBI'. Ncbi.nlm.nih.gov. N.p., 2015. Web. 20 Nov. 2015.

  3. Emedicine.medscape.com,. 'Osteoarthritis: Practice Essentials, Background, Anatomy'. N.p., 2015. Web. 20 Nov. 2015.

  4. Kumar, Parveen J, and Michael L Clark. Kumar & Clark's Clinical Medicine. Print.

  5. Mayoclinic.org,. 'Osteoarthritis - Mayo Clinic'. N.p., 2015. Web. 20 Nov. 2015.

  6. Nhs.uk,. 'Osteoarthritis - Treatment - NHS Choices'. N.p., 2015. Web. 20 Nov. 2015.

  7. Emedicine.medscape.com,. 'Osteoarthritis: Practice Essentials, Background, Anatomy'. N.p., 2015. Web. 20 Nov. 2015.

  8. Uptodate.com,. 'Osteoarthritis Symptoms And Diagnosis'. N.p., 2015. Web. 20 Nov. 2015.

  9. Arthritis.org,. 'Osteoarthritis Diagnosis'. N.p., 2015. Web. 20 Nov. 2015.

  10.  Le, Tao, Kendall Krause, and Elizabeth Eby. First Aid For The Basic Sciences. New York: McGraw-Hill Medical, 2009. Print.

  11. Sattar, Husain A. Fundamentals Of Pathology. Chicago: Pathoma.com, 2011. Print.

  12. Fischer, Conrad. Master The Boards. Print.

  13. Agabegi, Steven S, Elizabeth D Agabegi, and Adam C Ring. Step-Up To Medicine. Philadelphia: Wolters Kluwer/Lippincott Williams &

  14. Wilkins, 2013. Print.

  15. HTTPS://EN.WIKIPEDIA.ORG/WIKI/FILE:HEALTH_JOINT.PNG (FIGURE 1).

  16.  HTTPS://EN.WIKIPEDIA.ORG/WIKI/FILE:JOINT_WITH_SEVERE_OSTEOATHRITIS.PNG (FIGURE 2).

  17. http://www.docjoints.com/arthritis-involving-the-knee-joint/ (Figure 3).

Written by:        Arwaf alRawaf

Reviewed by:    Abdullah AlAsaad

                         Lama Al Luhidan

Format Editor:  Adel Yasky