Osteoarthritis Concept Map | Pathophysiology | Clinical Presentation | OA Treatment Algorithm | Medications | OA and RA Comparison

osteoarthritis concept map
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Osteoarthritis Concept Map: An Overview


The map starts with osteoarthritis (OA) definition which states that OA is a degenerative non-inflammatory joint disease that is characterized by:
  • Progressive damage to the articular cartilage
  • Thickening of subchondral bone & joint capsule
  • Formation of osteophytes
  • Mild synovitis


Osteoarthritis is classified into:
A-     Idiopathic (primary) OA; there is no known underlying or predisposing cause.
B-     Secondary OA; which is associated with predisposing factors as: trauma, repetitive stress (occupation, sports), congenital abnormality, metabolic disorder, endocrine disorder (DM, obesity), or other bone/joint disease (Rheumatoid Arthritis, gout).


· Prevalence

  • most common joint disease
  • most common form of arthritis
  • most common reason for total hip & total-knee replacement
  • causes high morbidity and financial loss due to the important joints involved
  • knee OA is a leading cause of chronic disability in elderly
  • >90 % of persons > 40 yo have some radiographic changes of OA in weight-bearing
  •  joints, but only 30% are symptomatic

· Predominant age: 

>50 yr

· Sex

  • Hip OA: men > women
  • OA of interphalangeal joints, thumb base, and knee is more common in women

· Race: 

There are differences in prevalence and pattern of involved joints.

Risk Factors

The most powerful risk factor for osteoarthritis is age.
The most common risk factors are:
  • obesity (in women, there is a linear relationship between weight and risk),
  • previous occupation,
  • certain sports,
  • previous joint trauma
  • genetic predisposition
  • female gender
  • congenital/developmental defects
  • prior inflammatory joint disease
  • metabolic/endocrine disorders
Osteoarthritis develops when systemic factors combine with biomechanical susceptibilities. Systemic factors includes: age, gender, genetic predisposition, and nutritional status.


In order to understand osteoarthritis pathophysiology, you have to understand first its normal physiology. Thus, the map provides a brief explanation of osteoarthritis normal physiology, including articular cartilage functions, structure and composition.
After that, the map presents osteoarthritis pathophysiology through the following diagram:
Osteoarthritis Pathophysiology
Osteoarthritis Pathophysiology - Click to enlarge

Clinical Presentation & Diagnosis

General signs and symptoms

- Presentations from asymptomatic to severe joint pain, stiffness with functional limitations
- Asymmetric joint involvement
- No systemic manifestations

Joint pain

- may affect ≥ 1 joint
- deep ache
- worsened by use and relieved by rest
- persists during rest (in advanced cases)
- nocturnal pain interfering with sleep (in advanced hip OA)

Joint stiffness

- after periods of inactivity (e.g., sleep or automobile ride)
- lasts < 20 minutes
- impairs daily activities
- may be related to weather

• Mild synovitis (in advanced cases)
• Joint instability in weight-bearing joints
• Joint/bony crepitus (the sensation of bone rubbing against bone, evoked by joint movement)

Common sites in primary and secondary osteoarthritis are shown in images included in the map.

Joint examination may reveal:

         local tenderness, bony proliferation, soft tissue swelling,
         muscle atrophy, limited motion, and effusion

Laboratory Tests

        No specific laboratory test
        Aspirated synovial fluid (if obtained): leukocytosis and high viscosity.

Other Diagnostic Tests

        Radiologic evidence may be misleading
        Radiographic changes may include:
      are often absent in early osteoarthritis
joint-space narrowing, subchondral bone sclerosis, and osteophytes (with disease progression)
gross deformity and effusions (late osteoarthritis)

Osteoarthritis Treatment

The map details pharmacological treatment and offers brief information about non-pharmacological treatment and surgical interventions. A treatment algorithm for osteoarthritis is also included.
Medications used for the treatment of osteoarthritis are represented in the form of comparison table.
The table includes:
      Analgesics: Acetaminophen and Non-steroidal Anti-inflammatory Drugs (NSAIDs).
      Glucosamine and Chondroitin.
      Intra-articular therapy: Corticosteroids and Hyaluronic acid (Hyaluronan)
      Opioid analgesics (Tramadol)
      Topical analgesics: Topical NSAIDs Counterirritant.
The comparison includes medications' mechanisms of actions, indications, dosages, adverse drug reactions, drug interactions, precautions, and contraindications. 
osteoarthritis medications comparison
Osteoarthritis Medications Comparison

We hope you find Osteoarthritis Concept Map helpful.  The map is available for free, but you may like to have it as a printable version or a folded poster.

Map's Format



Folded Poster

The maps is printed out on ordinary A1 size paper and it is folded to be nearly sized as A4 paper.


To be sent to your address through the Egyptian Registered Postal Mail.

Delivery in Egypt takes few days,

Other countries: 2-3 weeks; you can upgrade to express mail. Please contact us for details.

Already printed out.

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Printable Version

The map is split into pages to be printed on six A4 papers. After printing them, you have to tape the edges together to make a folded poster.

Electornic; Download link.

A .pdf file for the printable version of the map will be available for download immediately after payment received.

Printing is allowed. The map is to be printed out on several pages.

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(See also Rheumatoid Arthritis Concept Map)

Osteoarthritis Concept Map by Maha Atef, B Pharm.
Version: 2.0
Last updated in: 1 July 2014
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