• Clinical science

Osteoarthritis (Osteoarthrosis)

Summary

Osteoarthritis (OA) is a disabling joint disease characterized by a noninflammatory degeneration of the joint complex (articular cartilage, subchondral bone, and synovium) that occurs with old age or from overuse. It mainly affects the weight-bearing and high-use joints, such as the hip, knee, hands, and vertebrae. Despite the widespread view that OA is a condition caused exclusively by degenerative “wear and tear” of the joints, newer research indicates a significant heterogeneity of causation, including pre-existing peculiarities of joint anatomy, genetics, local inflammation, mechanical forces, and biochemical processes that are affected by proinflammatory mediators and proteases. Major risk factors include advanced age, obesity, previous injuries, and asymmetrically stressed joints. In early-stage osteoarthritis, patients may complain of reduced range of motion, joint stiffness, and pain that is aggravated with heavy use. As the disease advances, nagging pain may also occur during the night or at rest. Diagnosis is predominantly based on clinical and radiological findings. Classic radiographic features of OA do not necessarily correlate with clinical symptoms and appearance. If lifestyle changes (moderate exercise, weight loss) and physical therapy fail to improve symptoms, analgesics are used for the management of active osteoarthritis. If medical interventions fail to improve the patient's quality of life, surgical procedures such as joint replacement may become necessary.

See “Osteoarthritis of the hip and knee.”

Epidemiology

  • Prevalence: most common joint disorder in the USA, affecting more than 20 million adults [1]
  • Incidence: increases with age
  • Sex: > , especially in patients older than 50 years
  • Incidence rates in specific joints: knee > hip > hand [1]

Epidemiological data refers to the US, unless otherwise specified.

Etiology

Classification

Osteoarthritis can be classified according to the underlying cause: [2]

Pathophysiology

Chronic mechanical stress on the joints and age-related decrease in proteoglycans cartilage loses elasticity and becomes friable → degeneration and inflammation of cartilage ; joint space narrowing and thickening and sclerosis of the subchondral bone [3][4]

Clinical features

  • Early clinical findings
  • Late clinical findings
    • Constant pain (including at night)
    • Morning joint stiffness usually lasting < 30 minutes
    • More severely restricted range of motion

Subtypes and variants

In contrast to osteoarthritis, rheumatoid arthritis does not affect the DIP joints.

Diagnostics

Osteoarthritis is usually diagnosed on the basis of clinical features. Radiographic evidence of joint degeneration supports the diagnosis of OA. [1]

Radiological signs of osteoarthritis [1]

The patient's history and clinical diagnosis are essential for the assessment and treatment of osteoarthritis. Radiographic signs often do not correlate with the patient's perception and clinical findings.

Other tests

Differential diagnoses

See “Differential diagnoses of inflammatory arthritis.”

The differential diagnoses listed here are not exhaustive.

Treatment

Pharmacotherapy should be used as acute and symptomatic therapy only; long-term NSAID therapy should be avoided due to its many side effects.

  • 1. Litwic A, Edwards MH, Dennison EM, Cooper C. Epidemiology and burden of osteoarthritis. Br Med Bull. 2013; 105(1): pp. 185–199. doi: 10.1093/bmb/lds038.
  • 2. Altman R, Asch E, Bloch D, et al. Development of criteria for the classification and reporting of osteoarthritis: Classification of osteoarthritis of the knee. Arthritis & Rheumatism. 1986; 29(8): pp. 1039–1049. doi: 10.1002/art.1780290816.
  • 3. Liu-Bryan R, Terkeltaub R. Emerging regulators of the inflammatory process in osteoarthritis. Nat Rev Rheumatol. 2014. doi: 10.1038/nrrheum.2014.162.
  • 4. Lane NE, Brandt K, Hawker G et al . OARSI-FDA initiative: defining the disease state of osteoarthritis. Osteoarthritis Cartilage. 2011. doi: 10.1016/j.joca.2010.09.013.
  • 5. American Academy of Orthopaedic Surgeons. Treatment of Osteoarthritis of the Knee, 2nd edition - Summary of Recommendations. url: https://www.aaos.org/cc_files/aaosorg/research/guidelines/oaksummaryofrecommendations.pdf Accessed January 9, 2019.
  • 6. Hochberg MC, Altman RD, April KT, et al. American College of Rheumatology 2012 recommendations for the use of nonpharmacologic and pharmacologic therapies in osteoarthritis of the hand, hip, and knee. Arthritis Care Res. 2012; 64(4): pp. 465–474. doi: 10.1002/acr.21596.
  • 7. Ayhan E, Kesmezacar H, Akgun I. Intraarticular injections (corticosteroid, hyaluronic acid, platelet rich plasma) for the knee osteoarthritis. World J Orthop. 2014; 5(3): pp. 315–361. doi: 10.5312/wjo.v5.i3.351.
last updated 11/10/2020
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