• We are sorry, but NCBI web applications do not support your browser and may not function properly. More information
Logo of nihpaAbout Author manuscriptsSubmit a manuscriptNIH Public Access; Author Manuscript; Accepted for publication in peer reviewed journal;
Ann Rheum Dis. Author manuscript; available in PMC May 1, 2011.
Published in final edited form as:
PMCID: PMC2859109
NIHMSID: NIHMS149992

Changes in the rates of joint surgery among patients with Rheumatoid Arthritis in California, 1983–2007

Grant H. Louie, MD, MHS and Michael M. Ward, MD, MPH

Abstract

Objectives

Treatment of patients with rheumatoid arthritis (RA) has improved markedly over the past 25 years. We investigated if rates of joint surgery, a long-term consequence of poorly-controlled RA, have changed over this period.

Methods

In this population-based, serial cross-sectional study of patients aged ≥ 40 years with RA in California, we examined trends in annual rates of total knee arthroplasty, total hip arthroplasty, total ankle arthroplasty or arthrodesis, and total wrist arthroplasty or arthrodesis from 1983–2007.

Results

Rates of joint surgery peaked in the 1990s and since have decreased. Among patients aged 40–59 years, rates of knee surgery in 2003–2007 were 19% lower than in 1983–1987 (adjusted rate ratio 0.81; 95% confidence interval (CI) 0.74 – 0.87, P < 0.0001), while rates of hip surgery in 2003–2007 were 40% lower (P < 0.0001). Rates of knee and hip surgery did not decrease in patients aged ≥ 60 years but increased as observed in the general population. Compared with rates of ankle and wrist surgery in the mid-1980s, rates in the mid-2000s decreased significantly in both age groups.

Conclusions

Rates of joint surgery in RA peaked in the 1990s and have declined thereafter, suggesting that long-term outcomes of RA are improving.

Keywords: rheumatoid arthritis, joint surgery, orthopedic surgery, arthroplasty, arthrodesis

A long-term sequela of inadequately controlled chronic synovitis in patients with rheumatoid arthritis (RA) is joint damage severe enough to require surgery (1). Several studies have suggested that rates of arthroplasty among patients with RA have decreased in recent decades (27). Although the reasons for this finding are uncertain, these decreases mirror changes in other measures of RA severity and followed the shift to more aggressive anti-rheumatic treatment (8). We previously found that rates of total knee arthroplasty in patients with RA in California declined in 1998–2001 after peaking in the mid-1990s (3). It is unknown if these rates have continued to decrease. In this population-based, serial cross-sectional study, we examined rates of total knee arthroplasty through 2007, and investigated if rates of total hip arthroplasty and ankle or wrist surgery among patients with RA in California decreased between 1983 and 2007.

METHODS

Source of Data

We used data on inpatient hospitalizations from the California Office of Statewide Health Planning and Development (9) from 1983 (the first year of the database) to 2007. This office receives discharge abstracts, which include a record of diagnoses and procedures, for all hospitalizations, and performs extensive reliability checks to ensure data accuracy. The study protocol was exempted from human subjects review by the institutional ethics committee.

Patients and Procedures

We tabulated the number of hospitalizations in which total knee arthroplasty, total hip arthroplasty, ankle arthrodesis or arthroplasty [hereafter “ankle surgery”], or wrist arthrodesis or arthroplasty [hereafter “wrist surgery”] were recorded. We limited the analyses to patients with RA aged 40 years or older because including younger patients at low risk for surgery would have decreased our ability to detect changes over time. Because unique patient identifiers were not available before 1991 or after 2000, analyses were based on the number of procedures, and not the number of patients.

Statistical Analysis

We computed the annual crude rate of each procedure by dividing the number of procedures in each year by the estimated number of patients with RA in California in each year. We estimated the number of patients with RA by applying age, sex, and race-specific prevalences of RA (based on data from the Third National Health and Nutrition Examination Survey (10)) to yearly estimates of the population of California (2,11). We standardized crude rates to the age, sex, and race distribution of the RA population in 2000. To provide more stable estimates, we pooled data in five equal 5-year periods, and used Poisson regression models to compare adjusted rates across time periods. Adjusted rate ratios were computed using both the first 5-year study period (1983–1987) or the peak time period as the referent group. We used a similar approach to calculate adjusted rates of procedures from 1998 to 2007 among patients aged 40 years or older in the general population. Data on hospitalizations not related to RA for years prior to 1998 were not available. Analyses were performed using SAS version 9.1.3 (SAS Institute, Cary, NC).

RESULTS

Joint Surgery in Patients with RA

The adjusted rate of total knee arthroplasty was 459 per 100,000 persons with RA in 1983, attained a maximum of 556 per 100,000 persons in 1997, and then decreased to 467 per 100,000 persons in 2007 (Figure 1A). The relative risk of total knee arthroplasty was 9% higher in 1993–1997 than in 1983–1987, but was significantly lower by 8% in 1998–2002 (Table 1).

Figure 1
Annual adjusted rates of (A) total knee arthroplasty, (B) total hip arthroplasty, (C) total ankle arthroplasty or arthrodesis, and (D) total wrist arthroplasty or arthrodesis per 100,000 persons with rheumatoid arthritis from 1983–2007. Values ...
Table 1
Adjusted rates and rate ratios of joint surgery among patients with rheumatoid arthritis from 1983–2007*

The rate increased slightly in 2003–2007. The relative risk of total knee arthroplasty was 12% lower in 2003–2007 compared to the peak period of 1993–1997. The recent increase in rates was concentrated among patients aged 60 years and older. Among those aged 40–59 years, there was a progressive decrease in rates over time, with a relative risk of total knee arthroplasty that was 19% lower in 2003–2007 than in 1983–1987.

Rates of total hip arthroplasty steadily increased from 1983 to 1996, and then declined (Figure 1B). The risk of total hip arthroplasty was 32% higher in 1993–1997 than in 1983–1987, and nearly the same in 2003–2007 as in 1983–1987 (Table 1). Compared to the peak period of 1993–1997, the risk of total hip arthroplasty was 23% lower in 2003–2007. Similar to the findings for total knee arthroplasty, rates of total hip arthroplasty decreased progressively over time among those aged 40–59 years, with a relative risk that was 40% lower in 2003–2007 than in 1983–1987.

Rates of ankle surgery peaked in the mid-1990s (Figure 1C). The relative risk of ankle surgery was 21% higher in 1993–1997 than in 1983–1987 (Table 1). Thereafter, the risk decreased, such that the relative risk was 39% lower in 2003–2007 compared to 1983–1987.

Adjusted rates of wrist surgery in patients with RA increased from 1983 to 1990 before decreasing in the most recent periods (Figure 1D). The relative risk of wrist surgery was nearly 2-fold higher in 1988–1992 than in 1983–1987, but 59% lower in 2003–2007 than in 1983–1987 (Table 1). Trends in rates of ankle and wrist surgery were similar in younger and older patients. For all four procedures, trends were similar in men and women.

Joint Surgery in the California General Population

Between 1998 and 2007, annual adjusted rates of total knee arthroplasty among the general population increased steadily, from 260 per 100,000 persons in 1998 to 360 per 100,000 persons in 2007. Adjusted rates of total hip arthroplasty decreased slightly from 332 per 100,000 persons in 1998 to 290 per 100,000 persons in 2007, while adjusted rates of ankle surgery were stable (5.8 per 100,000 persons in 2000 to 5.1 per 100,000 persons in 2007). Adjusted rates of wrist surgery decreased slightly from 0.4 per 100,000 persons in 2000 to 0.2 per 100,000 persons in 2007.

DISCUSSION

Rates of joint surgery in patients with RA in California peaked in the 1990s and have since decreased. Rates of ankle and wrist surgery were markedly lower in the mid-2000s compared to the mid-1980s. Rates of total knee arthroplasty and total hip arthroplasty also decreased substantially (19% and 40%, respectively) among patients aged 40–59 years. Rates of total knee and hip arthroplasty did not decrease in older patients, and paralleled increases observed in the general population.

Our results are consistent with other recent reports of temporal trends in rates of orthopedic surgery among patients with RA (47). In a population-based retrospective study of patients with RA in Central Finland, rates of total hip or knee replacement from 1986–2003 were essentially stable (4). Rates of joint arthroplasty among patients with chronic inflammatory arthritides (86% with RA) in Norway from 1994–2004 either decreased (hip) or were stable (knee), while rates of ankle and wrist arthrodesis significantly decreased (5). A study of the Swedish National Hospital Discharge Register found declining rates for lower extremity surgeries from 1987–2001 (6) and upper extremity surgeries from 1998–2004 among hospitalized patients with RA (7).

Reasons frequently proposed to account for the recent declines in radiographic severity, functional impairment, and rates of joint surgery in RA are either that these represent responses to improvements in the way anti-rheumatic medications are used, or that RA is evolving to become milder (1214). Both changes in treatment and changes in the natural history may have an influence on the severity of RA, but the pattern of a gradual increase in rates of joint surgery through the 1990s, followed by a more recent decline, is more consistent with a treatment effect. A gradually progressive decline in rates might have been expected if a change in the natural history of RA was primarily responsible. The timing of the decline is also consistent with the time necessary for the new treatment strategy to be widely adopted, and for the first generation of patients treated under the new strategy to replace previous generations and reach the stage of RA when joint surgeries become more common (15). This may also account for the observation that decreases in rates of joint surgery were more pronounced among younger patients. This time lag also suggests that the effect of biologic agents on rates of joint surgery at the population level may not be evident for some time.

The strengths of our study include the investigation of rates of four types of joint surgery over a 25-year study period in a large population-based sample. Potential limitations of our study include possible coding errors in the database which could have misclassified some patients. However, validation studies showed major diagnoses to be accurately coded (3). We also could not determine whether the same patient underwent multiple surgeries (e.g. bilateral joints or revisions). Therefore, our rates were likely higher than rates based on the number of patients with joint surgery.

Our results demonstrate that rates of joint surgery in patients with RA peaked in the 1990s and since have decreased. Wrist and ankle surgery declined markedly, while progressive decreases in rates of total knee arthroplasty and total hip arthroplasty occurred in younger patients. Collectively these findings suggest that long-term health outcomes of RA are improving.

Acknowledgments

This work was supported by the Intramural Research Program, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health.

Footnotes

Updated information and services can be found at:

http://ard.bmj.com/cgi/content/abstract/ard.2009.112474v1

COMPETING INTERESTS

None.

Contributor Information

Grant H. Louie, Intramural Research Program, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, U.S. Department of Health and Human Services.

Michael M. Ward, Intramural Research Program, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, U.S. Department of Health and Human Services.

References

1. Massardo L, Gabriel SE, Crowson CS, O’Fallon WM, Matteson EL. A population-based assessment of the use of orthopedic surgery in patients with rheumatoid arthritis. J Rheumatol. 2002;29:52–6. [PubMed]
2. da Silva E, Doran MF, Crowson CS, O’Fallon WM, Matteson EL. Declining use of orthopedic surgery in patients with rheumatoid arthritis? Results of a long-term, population-based assessment. Arthritis Rheum. 2003;49:216–20. [PubMed]
3. Ward MM. Decreases in rates of hospitalizations for manifestations of severe rheumatoid arthritis, 1983 – 2001. Arthritis Rheum. 2004;50:1122–31. [PubMed]
4. Sokka T, Kautiainen H, Hannonen P. Stable occurrence of knee and hip total joint replacement in Central Finland between 1986 and 2003: an indication of improved long-term outcomes of rheumatoid arthritis. Ann Rheum Dis. 2007;66:341–4. [PMC free article] [PubMed]
5. Fevang BT, Lie SA, Havelin LI, Engesaeter LB, Furnes O. Reduction in orthopedic surgery among patients with chronic inflammatory joint disease in Norway, 1994–2004. Arthritis Rheum. 2007;57:529–32. [PubMed]
6. Weiss RJ, Stark A, Wick MC, Ehlin A, Palmblad K, Wretenberg P. Orthopaedic surgery of the lower limbs in 49802 rheumatoid arthritis patients: results from the Swedish National Inpatient Registry during 1987 to 2001. Ann Rheum Dis. 2006;65:335–41. [PMC free article] [PubMed]
7. Weiss RJ, Ehlin A, Montgomery SM, Wick MC, Stark A, Wretenberg P. Decrease of RA-related orthopaedic surgery of the upper limbs between 1998 and 2004: data from 54579 Swedish RA inpatients. Rheumatology. 2008;47:491–4. [PubMed]
8. Wilske KR, Healey LA. Remodeling the pyramid—a concept whose time has come. J Rheumatol. 1989;16:565–7. [PubMed]
9. Office of Statewide Health Planning and Development. Report of results from the OSHPD reabstracting project: an evaluation of the reliability of selected patient discharge data, July through December 1988. Sacramento, CA: Office of Statewide Health Planning and Development; 1990.
10. Rasch EK, Hirsch R, Paulose-Ram R, Hochberg MC. Prevalence of rheumatoid arthritis in persons 60 years of age and older in the United States: effect of different methods of case classification. Arthritis Rheum. 2003;48:917–26. [PubMed]
11. State of California Department of Finance. Demographic, Economic and Financial Research. www.dof.ca.gov/HTML/DEMOGRAP/Data/DRUdatafiles.php.
12. Finckh A, Choi HK, Wolfe F. Progression of radiographic joint damage in different eras: trends towards milder disease in rheumatoid arthritis are attributable to improved treatment. Ann Rheum Dis. 2006;65:1192–7. [PMC free article] [PubMed]
13. Fries JF, Williams CA, Morfeld D, Singh G, Sibley J. Reduction in long-term disability in patients with rheumatoid arthritis by disease-modifying antirheumatic drug-based treatment strategies. Arthritis Rheum. 1996;39:616–22. [PubMed]
14. Silman A, Davies P, Currey HL, Evans SJ. Is rheumatoid arthritis becoming less severe? J Chron Dis. 1983;36:891–7. [PubMed]
15. Wolfe F, Zwillich SH. The long-term outcomes of rheumatoid arthritis: a 23-year prospective, longitudinal study of total joint replacement and its predictors in 1,600 patients with rheumatoid arthritis. Arthritis Rheum. 1998;41:1072–82. [PubMed]
PubReader format: click here to try

Formats:

Related citations in PubMed

See reviews...See all...

Cited by other articles in PMC

See all...

Links

  • MedGen
    MedGen
    Related information in MedGen
  • PubMed
    PubMed
    PubMed citations for these articles

Recent Activity

Your browsing activity is empty.

Activity recording is turned off.

Turn recording back on

See more...