Osteoarthritis (OA)
Study guide:
Definition:
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Osteoarthritis is a degenerative joint disease that results from breakdown of joint cartilage and underlying bone.
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The most common form of arthritis, often affects joints of the hands, knees, hips and spine.
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The pain and stiffness may become severe enough to affect daily activities.
Epidemiology:
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In Saudi Arabia:
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One study showed that Radiographic OA was seen in (53.3%) of adult males and in (60.9%) of adult females.
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Worldwide:
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In the United States osteoarthritis affects more than 20 million individuals.
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Approximately 80-90% of individuals older than 65 years have evidence of radiographic primary osteoarthritis.
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In individuals older than 55 years, the prevalence of osteoarthritis is higher among women.
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Risk factors:
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Aging (Common after 60): Most Important Risk Factor!
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Gender: Women are more likely to develop osteoarthritis.
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Congenital disorders of joints.
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Diabetes
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Inflammatory diseases such as Perthes' disease and chronic forms of arthritis (e.g., costochondritis, gout, and rheumatoid arthritis).
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Joint infection
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Obesity
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Joint injuries
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Genetics
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Bone deformities
Etiology:
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Geneticfactors:
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Rare defect in collagen production that makes up cartilage (OA as early as age 20).
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Environmental factors:
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Primary OA: idiopathic.
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Secondary OA:
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Pre-existing joint damage: e.g. Gout.
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Metabolic disease: e.g. Acromegaly.
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Systemic disease: e.g. sickle cell disease.
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Pathophysiology:
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Onset:
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Collagen matrix disorganization and#proteoglycan content within cartilage.
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Breakdown of collagen fibers -> ^ water content (due to overall loss of proteoglycans
as the collagen was lost).
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As osteoarthritis progresses:
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Proteoglycans level drops -> the cartilage soften and lose compromising joint surface integrity.
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Over time:
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Loss of cartilage -> loss of joint space.
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Weight-bearing joints have greater joint-space narrowing.
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Articular cartilage damage and loss: cartilage damage results in exposure of subchondral joint, loss of joint space, and change in joint stress.
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Eburnation: increased stress on the exposed bone will result in increase in its density.
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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).
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Damaged cartilage could be found in the joint space as small fragments known as Joint Mice.
Clinical Presentation:
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Symptoms:
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Joint pain that’s worse with movement
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Morning joint stiffness
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Functional limitation
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Signs:
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Crepitus
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Restricted movement
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Bony enlargement
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Joint effusion and variable levels of inflammation
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Bony instability and muscle wasting
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Diagnosis (made based on clinical and radiographic findings):
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History:
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Palpable bony joint enlargement
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Morning stiffness
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Pain
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Physical Examination:
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Reduced range of motion
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Joint malalignment
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Crepitus
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No inflammatory signs
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X-ray: Most accurate test. Helps to track the status of OA over time (image below). Findings: presence of osteophytes and joint space narrowing.
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Other Tests: Usually normal in OA.
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Aspiration of synovial fluid: to rule out other inflammatory arthropathies.

Management:
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Lifestyle changes (Non-pharmacological):
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Exercise.
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Weight loss.
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Use assistive devices.
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Physical therapy
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Appropriate footwear
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Pharmacological treatment: (see table)
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Surgery:
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Arthroplasty: Joint replacement therapy
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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.
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Follow up:
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History: Address palpable bony joint enlargement, morning stiffness, and pain.
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Physical Examination: Check for reduced range of motion and joint malalignment.
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Complications:
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Sleep disruption
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Reduced quality of life
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Reduced productivity
References:
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AA, Al-Arfaj. 'Prevalence Of Radiographic Knee Osteoarthritis In Saudi Arabia. - Pubmed - NCBI'. Ncbi.nlm.nih.gov. N.p., 2015. Web. 20 Nov. 2015.
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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.
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Emedicine.medscape.com,. 'Osteoarthritis: Practice Essentials, Background, Anatomy'. N.p., 2015. Web. 20 Nov. 2015.
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Kumar, Parveen J, and Michael L Clark. Kumar & Clark's Clinical Medicine. Print.
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Mayoclinic.org,. 'Osteoarthritis - Mayo Clinic'. N.p., 2015. Web. 20 Nov. 2015.
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Nhs.uk,. 'Osteoarthritis - Treatment - NHS Choices'. N.p., 2015. Web. 20 Nov. 2015.
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Emedicine.medscape.com,. 'Osteoarthritis: Practice Essentials, Background, Anatomy'. N.p., 2015. Web. 20 Nov. 2015.
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Uptodate.com,. 'Osteoarthritis Symptoms And Diagnosis'. N.p., 2015. Web. 20 Nov. 2015.
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Arthritis.org,. 'Osteoarthritis Diagnosis'. N.p., 2015. Web. 20 Nov. 2015.
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Le, Tao, Kendall Krause, and Elizabeth Eby. First Aid For The Basic Sciences. New York: McGraw-Hill Medical, 2009. Print.
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Sattar, Husain A. Fundamentals Of Pathology. Chicago: Pathoma.com, 2011. Print.
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Fischer, Conrad. Master The Boards. Print.
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Agabegi, Steven S, Elizabeth D Agabegi, and Adam C Ring. Step-Up To Medicine. Philadelphia: Wolters Kluwer/Lippincott Williams &
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Wilkins, 2013. Print.
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HTTPS://EN.WIKIPEDIA.ORG/WIKI/FILE:HEALTH_JOINT.PNG (FIGURE 1).
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HTTPS://EN.WIKIPEDIA.ORG/WIKI/FILE:JOINT_WITH_SEVERE_OSTEOATHRITIS.PNG (FIGURE 2).
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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