Skip directly to search Skip directly to A to Z list Skip directly to navigation Skip directly to site content Skip directly to page options
CDC Home

Osteoarthritis

Osteoarthritis (OA) is a disease of the entire joint involving the cartilage, joint lining, ligaments, and underlying bone. The breakdown of these tissues eventually leads to pain and joint stiffness. The joints most commonly affected are the knees, hips, and those in the hands and spine. The specific causes of OA are unknown, but are believed to be a result of both mechanical and molecular events in the affected joint. Disease onset is gradual and usually begins after the age of 40. There is currently no cure for OA. Treatment for OA focuses on relieving symptoms and improving function, and can include a combination of patient education, physical therapy, weight control, use of medications, and eventually total joint replacement.

I. Background

  • Also known as degenerative joint disease.
  • Most common form of arthritis.
  • Classified as: Idiopathic (localized or generalized) or Secondary (traumatic, congenital, metabolic/endocrine/neuropathic and other medical causes).
  • Characterized by focal and progressive loss of the hyaline cartilage of joints, underlying bony changes.
  • Usually defined by symptoms, pathology or combination 1
    • Pathology = radiographic changes (joint space narrowing, osteophytes, and bony sclerosis.)
    • Symptoms = pain, swelling, and stiffness.
  • The American College of Rheumatology (ACR) has published clinical classification guidelines for OA of the hand [PDF - 1.31MB], hip [PDF - 1.31MB], and knee.

Top of Page

II. Prevalence

  •  Overall, in the United States,  OA affects 13.9% of adults aged 25 years and older and 33.6% (12.4 million) of those 65+ in 2005; an estimated 26.9 million US adults in 2005 up from 21 million in 1990 (believed to be conservative estimate).2
  • Average annual prevalence of OA in the ambulatory health care system in the United States, from 2001–2005, was estimated to be 3.5%  which amounts to 7.7 million with OA.3
  •  Average annual prevalence of OA in the ambulatory health care system in the United States, from 2001–2005, was estimated to be 3.5%  which amounts to 7.7 million with OA.3
    • Knee
      • Age ≥60 years=  37.4 (42.1 female; 31.2 male).4
      • Age ≥60 years=  47.8.5
      • Age ≥45 years= 19.2 (19.3 female; 18.6 male.6
      • Age ≥45 years= 37.4 (42.1 female; 31.2 male.7
      • Age ≥26 years=4.9 (4.9 female; 4.6 male.6
    • Hip
      • Age ≥45 years = 28.0 (29.5 female; 25.4 male).8
  • Symptomatic radiographic OA—prevalence per 100
    • Hand
      • Age ≥26 years = 6.8 (9.2 female; 3.8male).9
      • Age ≥60 years= 8.0 overall.10
    • Knee
      • Age ≥60 years=  12.1 (10.0 female; 13.6 male).4
      • Age ≥45 years= 6.7 (7.2 female; 5.9 male).6 
      • Age ≥45 years= 16.7 (18.7 female; 13.5 male).
      • Age ≥26 years= 4.9 (4.9 female; 4.6 male).6 
    • Hip 
      • Age ≥45 years = 8.7 (9.3 female; 9.2 male).6

Top of Page

III. Incidence

  • Age and sex-standardized incidence rates of symptomatic radiographic OA in the in adults aged ≥20 years and older:
    • Hand OA = 100 per 100,000 person years.11
    • Hip OA = 88 per 100,000 person years.11
    • Knee OA = 240 per 100,000 person years.11
  • Among women in the adult population:
    • Incident radiographic knee OA 2-2.5% per year.5, 12, 13
    • Incident symptomatic radiographic knee OA 1% per year.12
    • Progressive radiographic knee OA 3-4% per year.5,12,13
  • Incidence rates of OA increased with age, and level off around age 80.14
  • Women had higher rates than men, especially after age 50.14
    • Men have 45% lower risk of incident knee OA and 36% reduced risk of hip OA than women.15

Top of Page

IV. Mortality

 

  • OA is associated with excess mortality.16
    • Deaths from all causes, cardiovascular deaths, and dementia deaths among adults with OA were 1.6,1.7, and 2.0 times higher compared with the general population.16
  • Annual average of 0.2 to 0.3 deaths per 100,000 population due to OA (1979–1988).17
  • OA accounts for ~6% of all arthritis-related deaths.17
  • ~ 500 deaths per year attributed to OA; numbers increased during the past 10 years.17
  • OA deaths are likely highly underestimated. For example, gastrointestinal bleeding due to treatment with NSAIDs is not counted. 17

Top of Page

V. Hospitalizations

  • OA accounts for 69.9% of all arthritis-related hospitalizations; 814,900 hospitalizations for OA as principal diagnosis in 2006.18
  • Knee and hip joint replacement procedures (usually for OA) accounted for 35% of total arthritis-related procedures during hospitalization.19
  • Nationally, from 1991 to 2007 the rate (per 100,000) of total knee replacement increased 187% from 192.2 to 551.3. In addition, the rate (per 100,000) of total hip replacement increased 86.2% from 135.7 to 252.7.18
  • Non-Hispanic Blacks and persons with low income have lower rates of total knee replacement but higher complications and mortality than Non-Hispanic whites.20,21

Top of Page

VI. Ambulatory Care

  • OA accounted for an annual prevalence of 20.9 million (26.8%) of all arthritis-related ambulatory medical care visits from 2001-2005.3
  • About 39% of people with OA report inability to access needed health care rehabilitative services.22

Top of Page

VII. Costs

  • Estimated costs due to hospital expenditures of total knee and hip joint replacements, respectively, $28.5 billion and $13.7 billion in 2009.23
  • Average direct costs of OA per patient ~$2,600 per year.19
  • Total (direct and indirect) annual costs of OA per patient = $5700 (US dollars FY2000).24
  • Job-related OA costs $3.4 to $13.2 billion per year.14

Top of Page

VIII. Impact on health-related quality of life (HRQOL) [AAOS Fact Sheet; NHANES III data]

  • OA of the knee is 1 of 5 leading causes of disability among non-institutionalized adults. 25
  • About 80% of patients with OA have some degree of movement limitation.
    • 25% cannot perform major activities of daily living (ADL's), 11% of adults with knee OA need help with personal care and 14% require help with routine needs.
  • About 40% of adults with knee OA reported their health "poor" or "fair."
  • In 1999, adults with knee OA reported more than 13 days of lost work due to health problems.
  • Hip/knee OA ranked high in disability adjusted life years (DALYs)27 and years lived with disability (YLDs).26

Top of Page

IX. Unique characteristics

  • Disease in weight bearing joints has greater clinical impact.
  • About 20%–35% of knee OA and ~50% of hip and hand OA may be genetically determined.27,28
  • Established modifiable and non-modifiable risk factors7,27,28,29,30,31:
    • Modifiable
      • Excess body mass (especially knee OA).
      • Joint injury (sports, work, trauma).
      • Knee pain.
      • Hand OA is a risk factor for knee OA.
      • Occupation (due to excessive mechanical stress: hard labor, heavy lifting, knee bending, repetitive motion).
        • Men—often due to work that includes construction/mechanics, agriculture, blue collar laborers, and engineers.
        • Women—often due to work that includes cleaning, construction, agriculture, and small business and retail.
      • Structural malalignment, muscle weakness.
    • Non-modifiable.
      • Gender (women higher risk).
      • Age (increases with age and levels around age 75).
      • Race (some Asian populations have lower risk).
      • Genetic predisposition.
  • Other possible factors:
    • Estrogen deficiency (estrogen replacement therapy (ERT) may reduce risk of knee/hip OA).
    • High bone density may increase risk of knee).
    • Vitamins C, E, and D—equivocal reports.
    • C-reactive protein (increased risk with higher levels).

Top of Page

X. References

  1. American Academy of Orthopaedic Surgeons. Osteoarthritis. http://orthoinfo.aaos.org/topic.cfm?topic=a00227  Accessed 04-07-2014
  2. Lawrence RC, Felson DT, Helmick CG, et al. Estimates of the prevalence of arthritis and other rheumatic conditions in the United States. Part II. Arthritis Rheum. 2008;58(1):26-35.
  3. Sacks JJ, Luo Y-H, Helmick CG. Prevalence of specific types of arthritis and other rheumatic conditions in the ambulatory health care system in the   
    United States, 2001–2005.  Arthritis Care & Research. 2010;62 (4):460-464.
  4. Dillon CF, Rasch EK, Gu Q, Hirsch R. Prevalence of knee osteoarthritis in the United States: arthritis data from the Third National Health and Nutrition Examination Survey 1991–1994. J Rheumatol, 2006;33(11):2271-2279.
  5. Leyland KM, Hart DJ, Javaid MK, Judge A, et al. The natural history of radiographic knee osteoarthritis: a fourteen-year population-based cohort study. Arthritis Rheum 2012;64(7):2243-51.
  6. Felson DT, Naimark A, Anderson J, Kazis L, Castelli W, Meenan RF. The prevalence of knee osteoarthritis in the elderly. The Framingham Osteoarthritis Study. Arthritis Rheum. 1987;30(8):914-918.
  7. Jordan JM, Helmick CG, Renner JB, et al. Prevalence of knee symptoms and radiographic and symptomatic knee osteoarthritis in African Americans and Caucasians: The Johnston County Osteoarthritis Project. J Rheumatol. 2007;34(1):172-180.
  8. Jordan JM, Helmick CG, Renner JB, et al. Prevalence of hip symptoms and radiographic and symptomatic hip osteoarthritis in African Americans and Caucasians: the Johnston County Osteoarthritis Project. J Rheumatol 2009;36(4):809-15.
  9. Zhang Y, Niu J, Kelly-Hayes M, et al. Prevalence of symptomatic hand osteoarthritis and its impact on functional status among elderly: the Framingham Study. Am J Epidemiol.2002;156:1021-7.
  10. Dillon CF, Hirsch R, Rasch EK, Gu Q. Symptomatic hand osteoarthritis in the United States: prevalence and functional impairment estimates from the third U.S. National Health and Nutrition Examination Survey, 1991–1994. Am J Phys Med Rehabil, 2007;86(1):12-21.
  11. Oliveria SA, Felson DT, Reed JI, et al. Incidence of symptomatic hand, hip, and knee osteoarthritis among patients in a health maintenance organization. Arthritis Rheum. 1995;38(8):1134-1141.
  12. Felson DT, Zhang Y, Hannan MT, et al. The incidence and natural history of knee osteoarthritis in the elderly. The Framingham Osteoarthritis Study. Arthritis Rheum. 1995;38(10):1500-1505.
  13. Cooper C, Snow S, McAlindon TE, et al .Risk factors for the incidence and progression of radiographic knee osteoarthritis. Arthritis Rheum. 2000;43(5):995-1000.
  14. Buckwalter JA, Saltzman C, Brown T. The impact of osteoarthritis. Clin Orthoped Rel Res. 2004:427S: S6-S15.
  15. Srikanth VK, Fryer JL, Zhai G, Winzenberg TM, Hosmer D, Jones G. A meta-analysis of sex difference prevalence, incidence and severity of osteoarthritis. Osteoarthritis Cartilage. 2005;13:769-781.
  16. Nüesch E, Dieppe P, Reichenbach S, et al. All cause and disease specific mortality in patients with knee or hip osteoarthritis: population based cohort study. BMJ. 2011;342:d1165.
  17. Sacks JJ, Helmick CG, Langmaid G. Deaths from arthritis and other rheumatic conditions, United States, 1979–1998. J Rheumatol. 2004;31:1823-1828.
  18. Arthritis and Related Conditions Chapter 4. http://www.boneandjointburden.org/pdfs/BMUS_chpt4_arthritis.pdf. Accessed 04-07-2014
  19. Gabriel SE, Crowson CS, Campion ME, et al. Direct medical costs unique to people with arthritis. J Rheumatol. 1997;24(4):719–725.
  20. Mahomed NN, Barrett J, Katz JN Baron JA, Wright J, Losina E. Epidemiology of total knee replacements in the United States Medicare population. J Bone Joint Surg Am. 2005;87(6):1222-1228.
  21. CDC. Racial disparities in total knee replacement among Medicare enrollees--United States, 2000–2006. MMWR. 2009;58(6):133-8.
  22. Hagglund KJ, Clark MJ, Hilton SA, Hewett JE. Access to healthcare services among persons with osteoarthritis and rheumatoid arthritis. Am J Phys Med Rehabil. 2005;84(9):702-711.
  23. Murphy L, Helmick CG.The impact of osteoarthritis in the United States: a population-health perspective. Am J Nurs. 2012;112(3 Suppl 1):S13-9.
  24. Maetzel A, Li LC, Pencharz J, Tomlinson F Bombardier C. The economic burden associated with osteoarthritis, rheumatoid arthritis, and hypertension: a comparative study. Ann Rheum Dis. 2004;63(4):395-401.
  25. Guccione AA, Felson DT, Anderson JJ, et al. The effects of specific medical conditions on the functional limitations of elders in the Framingham Study. Am J Pub Health. 1994;84(3):351-358.
  26. Michaud CM, McKenna MT, Begg S, et al. The burden of disease and injury in the United States 1996. Popul Health Metr. 2006;4:11. http://www.pophealthmetrics.com/content/4/1/11. Accessed July, 19, 2007.
  27. Felson DT, Zhang Y. An update on the epidemiology of knee and hip osteoarthritis with a view to prevention. Arthritis Rheum. 1998;41(8):1343-1355.
  28. Felson DT. Risk factors for osteoarthritis. Clin Orthoped Rel Res. 2004;427S:S16-S21.
  29. Rossignol M, Leclerc A, Allaert FA, et al. Primary osteoarthritis of hip, knee and hand in relation to occupational exposure. Occup Environ Med. 2005;62:772-777.
  30. Cooper C, Snow S, McAlindon TE, et al. Risk factors for the incidence and progression of radiographic knee osteoarthritis. Arthritis Rheum. 2000;43(5):995-1000.
  31. Blagojevic M, Jinks C, Jeffery A, et al. Risk factors for onset of osteoarthritis of the knee in older adults: a systematic review and meta-analysis. Osteoarthritis Cartilage. 2010;18(1):24-33.

Top of Page

XI. Resources

Top of Page

 
 

Contact Us:
  • Arthritis Program
    Mailstop F-78
    4770 Buford Hwy NE
    Atlanta, GA 30341-3724
  • Phone: 770.488.5114
    Fax: 770.488.5964
  • Contact CDC-Info
USA.gov: The U.S. Government's Official Web PortalDepartment of Health and Human Services
Centers for Disease Control and Prevention   1600 Clifton Rd. Atlanta, GA 30329-4027, USA
800-CDC-INFO (800-232-4636) TTY: (888) 232-6348 - Contact CDC-INFO