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type=\u0022text\/css\u0022 rel=\u0022stylesheet\u0022 href=\u0022\/\/d282kpwvnogo5m.cloudfront.net\/sites\/default\/files\/advagg_css\/css__ce2QY63WIanKyr8eSq7eavr1XQRRmFD6ZSmwpyJi8lM__zXwFqpqmxrZOXXcd_TpBQpjuELbmIP9wBR5UuTDWAO4__YJWWMMdfCJuAFm5cUEp88OsodhO3ZA-2lzRfoBsSlk4.css\u0022 media=\u0022all\u0022 \/\u003E\n\u003Clink rel=\u0027stylesheet\u0027 type=\u0027text\/css\u0027 href=\u0027\/sites\/all\/modules\/contrib\/panels\/plugins\/layouts\/onecol\/onecol.css\u0027 \/\u003E\u003C\/head\u003E\u003Cbody\u003E\u003Cdiv class=\u0022panels-ajax-tab-panel panels-ajax-tab-panel-sageoa-tab-art\u0022\u003E\u003Cdiv class=\u0022panel-display panel-1col clearfix\u0022 \u003E\n  \u003Cdiv class=\u0022panel-panel panel-col\u0022\u003E\n    \u003Cdiv\u003E\u003Cdiv class=\u0022panel-pane pane-highwire-markup\u0022 \u003E\n  \n      \n  \n  \u003Cdiv class=\u0022pane-content\u0022\u003E\n    \u003Cdiv class=\u0022highwire-markup\u0022\u003E\u003Cdiv xmlns=\u0022http:\/\/www.w3.org\/1999\/xhtml\u0022 id=\u0022content-block-markup\u0022 xmlns:xhtml=\u0022http:\/\/www.w3.org\/1999\/xhtml\u0022\u003E\u003Cdiv class=\u0022article fulltext-view \u0022\u003E\u003Cspan class=\u0022highwire-journal-article-marker-start\u0022\u003E\u003C\/span\u003E\u003Cdiv class=\u0022section abstract\u0022 id=\u0022abstract-1\u0022\u003E\n      \u003Ch2\u003ESummary\u003C\/h2\u003E\n      \u003Cp id=\u0022p-1\u0022\u003EAn aging population, obesity, and the growing incidence of knee injuries in young people are factors that are likely to increase the demand for total joint replacement. This article discusses physical activity and osteoarthritis, as well as outcomes of total hip and total knee replacements.\u003C\/p\u003E\n   \u003C\/div\u003E\u003Cul class=\u0022kwd-group\u0022\u003E\u003Cli class=\u0022kwd\u0022\u003Earthritis\u003C\/li\u003E\u003C\/ul\u003E\u003Cdiv class=\u0022section\u0022 id=\u0022sec-1\u0022\u003E\n      \u003Cp id=\u0022p-2\u0022\u003EAn aging population, obesity, and the growing incidence of knee injuries in young people are factors that are likely to increase the demand for total joint replacement. Joanne M. Jordan, MD, University of North Carolina Rheumatology\/Thurston Arthritis Research Center, Chapel Hill, North Carolina, USA, provided an update on the topic.\u003C\/p\u003E\n      \u003Cp id=\u0022p-3\u0022\u003EBetween 1990 and 2002, the rate of primary hip replacement increased 50% to 60%, but knee replacements increased by as much 2.5- to 3-fold, even among the \u226585-year-old population [Singh JA et al. \u003Cem\u003EMayo Clin Proc\u003C\/em\u003E 2010]. Using a computer simulation model and population-based data from the 2008 census, an analysis published in 2011 found that 13% of individuals aged between 60 and 64 years in the United States (US) had symptomatic knee osteoarthritis (OA). Of those who survive another decade, 20% will have developed symptomatic severe or end-stage knee OA, with estimates ranging from 10% in nonobese individuals to as much as 35% in obese individuals [Holt HL et al. Osteoarthritis Cartilage 2011]. A Centers for Disease Control and Prevention report of joint replacements in the Medicare population between 2000 and 2006 found an increase of approximately 2 million procedures [\u003Cem\u003EMMWR.\u003C\/em\u003E 2009;58(6)].\u003C\/p\u003E\n      \u003Cp id=\u0022p-4\u0022\u003EMurphy et al., in a 2008 study, predicted that approximately 45% of individuals who live to 85 years in the United States would have symptomatic knee OA, with a lifetime risk in those who are obese that is nearly twice that of those with a body mass index (BMI) \u0026lt;25 kg\/m\u003Csup\u003E2\u003C\/sup\u003E (\u003Ca id=\u0022xref-table-wrap-1-1\u0022 class=\u0022xref-table\u0022 href=\u0022#T1\u0022\u003ETable 1\u003C\/a\u003E). A significantly higher risk in individuals with a history of knee injury was also noted (56.8, 95% CI, 48.4 to 65.2 vs 42.3, 95% CI, 37.2 to 47.4) [Murphy L et al. \u003Cem\u003EArthritis Rheum\u003C\/em\u003E 2008].\u003C\/p\u003E\n      \u003Cdiv id=\u0022T1\u0022 class=\u0022table pos-float\u0022\u003E\n         \u003Cdiv class=\u0022table-inline\u0022\u003E\n            \u003Cdiv class=\u0022callout\u0022\u003E\n               \u003Cspan\u003EView this table:\u003C\/span\u003E\n               \u003Cul class=\u0022callout-links\u0022\u003E\u003Cli class=\u00220 first\u0022\u003E\u003Ca href=\u0022\/\u0022 class=\u0022table-expand-inline\u0022 data-table-url=\u0022\/highwire\/markup\/12624\/expansion?postprocessors=highwire_figures%2Chighwire_math%2Chighwire_inline_linked_media%2Chighwire_embed\u0026amp;table-expand-inline=1\u0022 html=\u00221\u0022 fragment=\u0022#\u0022 external=\u00221\u0022 data-icon-position=\u0022\u0022 data-hide-link-title=\u00220\u0022\u003EView inline\u003C\/a\u003E\u003C\/li\u003E\u003Cli class=\u00221\u0022\u003E\u003Ca href=\u0022\/highwire\/markup\/12624\/expansion?width=1000\u0026amp;height=500\u0026amp;iframe=true\u0026amp;postprocessors=highwire_figures%2Chighwire_math%2Chighwire_inline_linked_media\u0022 class=\u0022colorbox colorbox-load table-expand-popup\u0022 rel=\u0022gallery-fragment-tables\u0022 data-icon-position=\u0022\u0022 data-hide-link-title=\u00220\u0022\u003EView popup\u003C\/a\u003E\u003C\/li\u003E\u003Cli class=\u00222 last\u0022\u003E\u003Ca href=\u0022\/highwire\/powerpoint\/12624\u0022 class=\u0022highwire-figure-link highwire-figure-link-ppt\u0022 data-icon-position=\u0022\u0022 data-hide-link-title=\u00220\u0022\u003EDownload powerpoint\u003C\/a\u003E\u003C\/li\u003E\u003C\/ul\u003E\n            \u003C\/div\u003E\n         \u003C\/div\u003E\n         \u003Cdiv class=\u0022table-caption\u0022\u003E\n            \u003Cspan class=\u0022table-label\u0022\u003ETable 1.\u003C\/span\u003E \n            \u003Cp id=\u0022p-5\u0022 class=\u0022first-child\u0022\u003ELifetime Risk of Knee OA.\u003C\/p\u003E\n         \u003Cdiv class=\u0022sb-div caption-clear\u0022\u003E\u003C\/div\u003E\u003C\/div\u003E\n      \u003C\/div\u003E\n      \u003Cp id=\u0022p-6\u0022\u003EAn analysis by Losina et al. found that total quality of life years that are lost due to knee OA was nearly double in obese individuals compared with nonobese people with knee OA, with Hispanic and African-American women losing disproportionately more quality of life years than their overall percentage of the population would otherwise suggest [Losina E et al. \u003Cem\u003EAnn Int Med\u003C\/em\u003E 2011].\u003C\/p\u003E\n      \u003Cp id=\u0022p-7\u0022\u003EAn analysis of the British Birth Cohort Study, which has been following 5000 individuals since 1946 (3035 of whom were alive and able to be followed), found that the risk of knee OA, assessed at age 53, is higher in those with a high BMI in adolescence and young adulthood, starting at age 20 for men and age 15 for women (95% CI, 1.11 to 1.71 per Z-score increase in BMI for men and 1.89 [95% CI 1.59 to 2.24 for women]), and exposure to high BMI throughout adulthood was most predictive of risk of developing knee OA in both men and women [Will AK et al. \u003Cem\u003EAnn Rheum Dis\u003C\/em\u003E 2011].\u003C\/p\u003E\n      \u003Cp id=\u0022p-8\u0022\u003EThese data suggest that weight control throughout life is important and that childhood weight tracks closely with adult weight but that the effect of childhood or adolescent weight is eliminated once weight at adult age is considered.\u003C\/p\u003E\n   \u003C\/div\u003E\u003Cdiv class=\u0022section\u0022 id=\u0022sec-2\u0022\u003E\n      \u003Ch2 class=\u0022\u0022\u003EPhysical Activity, Injury, and Osteoarthritis\u003C\/h2\u003E\n      \u003Cp id=\u0022p-9\u0022\u003EApproximately 12% of OA is related to injury, and the annual cost is approximately $3.1 billion [Brown TD et al. \u003Cem\u003EJ Orthop Trauma\u003C\/em\u003E 2006].\u003C\/p\u003E\n      \u003Cp id=\u0022p-10\u0022\u003EA study of relatively young male soccer players (aged 16 to 42 years at time of injury) found that 14 years after sustaining an ACL tear, 41% of injured knees would develop advanced OA, compared with only 4% of uninjured knees [von Porat A et al. \u003Cem\u003EAnn Rheum Dis\u003C\/em\u003E 2004]. In another study of female soccer players aged under 20 years at the time of injury, the OA rate was 51% in injured knees only 12 years postinjury, compared with an 8% rate of OA in uninjured knees [Lohmander LS et al. \u003Cem\u003EArthritis Rheum\u003C\/em\u003E 2004].\u003C\/p\u003E\n      \u003Cp id=\u0022p-11\u0022\u003EA recent epidemiological study found that approximately half of children in the US aged between 6 and 17 years (27 million children) play team sports, which may be predictive of a postinjury problem that will continue to grow [Caine DJ et al. \u003Cem\u003EBr J Sports Med\u003C\/em\u003E 2011]. Additionally, 65% of sports and recreational injuries that are seen in emergency departments occur in those aged younger than 19 years [\u003Cem\u003EMMWR.\u003C\/em\u003E 2002;51(33)].\u003C\/p\u003E\n      \u003Cp id=\u0022p-12\u0022\u003ESevere symptomatic OA is a significant public health issue that is clearly related to the aging of our society, obesity in childhood and throughout life, and joint injury. While total knee and hip replacements are increasing in frequency among all age groups, racial and ethnic disparities persist.\u003C\/p\u003E\n   \u003C\/div\u003E\u003Cdiv class=\u0022section\u0022 id=\u0022sec-3\u0022\u003E\n      \u003Ch2 class=\u0022\u0022\u003EOutcomes of Total Hip and Total Knee Replacement\u003C\/h2\u003E\n      \u003Cp id=\u0022p-13\u0022\u003EJeffrey Katz, MD, professor of medicine and orthopedics at Brigham and Women\u0027s Hospital, Boston, Massachusetts, USA, discussed total hip and knee replacement outcomes. His analysis placed outcomes into three relevant categories: the perioperative period, the honeymoon period (1 to 10 years postsurgery), and long-term follow-up of more than 10 years.\u003C\/p\u003E\n      \u003Cp id=\u0022p-14\u0022\u003EMortality within the first 90 days postsurgery ranges between 0.5% and 1% for new replacements and 2% to 2.5% for revisions. There is a higher rate for hip replacements versus knee replacements, with advanced age, male gender, low socioeconomic status, comorbidities (diabetes, cardiovascular disease, renal failure, dementia), African-American race, and hospitals that perform a low volume of procedures are associated with poor outcomes [Katz JN et al. \u003Cem\u003EJ Bone Joint Surg Am\u003C\/em\u003E 2001].\u003C\/p\u003E\n      \u003Cp id=\u0022p-15\u0022\u003EIn the first 90 days after surgery, total hip replacement (THR) recipients have a higher risk of death due to myocardial infarction, pulmonary embolism, and peptic ulcer than the general population. However, over the subsequent 12 years, THR recipients are less likely to die of these causes than the general population [Roberson et al. \u003Cem\u003EJBJS\u003C\/em\u003E 2007]. It is unclear whether this is reflective of favorable patient selection of healthier individuals for THR, or whether it may be a salubrious effect in terms of the functional benefits that are offered by the proceedure.\u003C\/p\u003E\n      \u003Cp id=\u0022p-16\u0022\u003EDuring the honeymoon period, patients exhibit a favorable improvement in pain during the first year. However, as Bourne et al. and others have demonstrated, there is significant variability around that improvement, with approximately 20% of total knee replacement patients dissatisfied with the end results [Bourne RB et al. Annual Meeting of the Knee Society 2010; Beswick A et al. ACR 2011]. Patients with residual pain at 6 months also have worse functional status and pain outcomes at 5 years [Katz JN et al. World Congress on Osteoarthritis 2011].\u003C\/p\u003E\n      \u003Cp id=\u0022p-17\u0022\u003EIn the long-term follow-up period, patients who underwent total joint replacement faced ongoing risks of infection, repeated dislocation, and revision. The risk of revision for infection after the first year of a THR is approximately 0.7% over 15 years, while the risk for knee replacement revision is approximately 1%. However, these figures fail to capture dislocations that may present in the emergency department.\u003C\/p\u003E\n      \u003Cp id=\u0022p-18\u0022\u003EThe lifetime risk of periprosthetic fracture is 1% to 2%, usually related to low-energy trauma, with some data pointing to older age, female gender, a history of rheumatoid arthritis, loose implant, peptic ulcer disease, and cardiovascular disease as being associated with fracture risk [Singh JA et al. ACR 2011; Della Rocca GJ et al. \u003Cem\u003EJ Orthop Trauma\u003C\/em\u003E 2011].\u003C\/p\u003E\n      \u003Cp id=\u0022p-19\u0022\u003EOverall, 12 years after total joint replacement, one-third of patients aged 65 to 75 years will have died; 9.4% will have had a revision procedure; and 61% will be alive and at risk for revision [Katz JB. In process.]. In the \u226575-year-old age group, 58% will have died; 5.7% will have undergone revision, and 35% will be alive and at risk of revision. The cumulative risk of revision for total knee replacement is about 0.5% per year and about 1% per year with hip replacement [Robersson O et al. \u003Cem\u003EActa Orthop\u003C\/em\u003E 2010].\u003C\/p\u003E\n   \u003C\/div\u003E\u003Cul class=\u0022copyright-statement\u0022\u003E\u003Cli class=\u0022fn\u0022 id=\u0022copyright-statement-1\u0022\u003E\u00a9 2011 MD Conference Express\u003C\/li\u003E\u003C\/ul\u003E\u003Cspan class=\u0022highwire-journal-article-marker-end\u0022\u003E\u003C\/span\u003E\u003C\/div\u003E\u003Cspan id=\u0022related-urls\u0022\u003E\u003C\/span\u003E\u003C\/div\u003E\u003Ca href=\u0022http:\/\/mdc.sagepub.com\/content\/11\/13\/24.abstract\u0022 class=\u0022hw-link hw-link-article-abstract\u0022 data-icon-position=\u0022\u0022 data-hide-link-title=\u00220\u0022\u003EView Summary\u003C\/a\u003E\u003C\/div\u003E  \u003C\/div\u003E\n\n  \n  \u003C\/div\u003E\n\u003C\/div\u003E\n  \u003C\/div\u003E\n\u003C\/div\u003E\n\u003C\/div\u003E\u003Cscript type=\u0022text\/javascript\u0022 src=\u0022http:\/\/mdc.sagepub.com\/sites\/all\/modules\/highwire\/highwire\/plugins\/highwire_markup_process\/js\/highwire_openurl.js?nzmwop\u0022\u003E\u003C\/script\u003E\n\u003Cscript type=\u0022text\/javascript\u0022 src=\u0022http:\/\/mdc.sagepub.com\/sites\/all\/modules\/highwire\/highwire\/plugins\/highwire_markup_process\/js\/highwire_tables.js?nzmwop\u0022\u003E\u003C\/script\u003E\n\u003C\/body\u003E\u003C\/html\u003E"}