Session Title: Orthopedics, Low Back Pain, and Rehabilitation
Session Type: Abstract Submissions (ACR)
Background/Purpose: Overall rates of total joint replacement surgeries (TJR) have increased dramatically over the past decades. By contrast, TJR rates among patients with rheumatoid arthritis (RA) are reported to be decreasing. The magnitude of such change, and whether it applies to all types of inflammatory arthritis (IA), is not clear. This study evaluates rates of TJR among patients with IA, [RA, juvenile idiopathic arthritis (JIA) and spondyloarthropathies (SpA)] and compares them to TJR patients with non-inflammatory conditions.
Methods: Administrative hospital discharge databases from 10 states (AZ, CA, CO, FL, IA, MA, NJ, NY, WA, WI) and census data annual population estimates were used to calculate combined rates per 100,000 population of knee arthroplasty, total and partial hip arthroplasty, and total and partial shoulder arthroplasty from 1991 to 2005. ICD-9-CM codes were used to identify specific diseases.
Results: There were 2,839,325 arthroplasties from 1991 to 2005, of which 76,665 (2.7%) were in IA patients. The proportion of TJR attributable to IA nearly halved during this period (3.9% in 1991 vs. 2.0% in 2005). TJR rate for non-inflammatory conditions almost doubled from 124.5 in 1991 to 247.5 in 2005, while the rate in IA patients was fairly steady (range: 4.4-5.2). Stratifying by IA subtype, the TJR rate decreased slightly for RA (4.6 vs. 4.5, p-value<0.001) decreased by 40% for JIA (0.31 vs. 0.22, p-value<0.001), and increased by 40% for SpA (0.22 vs. 0.31 p-value<0.001). From 1991 to 2005, the mean age at TJR for IA patients across all disease subtypes increased: RA (63.4 yrs ±12.7 vs. 64.9 yrs ±12.8, p-value<0.001), JIA (30.9 yrs ±12.2 vs. 36.7 yrs ±14.9, p-value <0.001), and SpA (54.3 yrs ±16.1 vs. 60.4 yrs ±13.9, p-value <0.001). In contrast, the mean age of non-IA decreased (71.5±11.8 yrs. vs. 69.0±12.0 yrs p<0.001). Among IA patients, neither age nor sex was statistically significantly related to TJR rates.
Conclusion: To our knowledge this is the largest cohort of TJR of patients with IA and the first study of TJR trends in patients with JIA and SpA. Surprisingly, TJR rates in RA showed minimal change despite the widespread introduction of methotrexate in the 1990s. JIA and SpA patients appear to be deferring TJR, with JIA patients requiring fewer procedures. Why SpA TJR rates increased is unclear. These data suggest there will be an ongoing need for orthopedists with expertise in operating on IA patients. Obtaining exposure during surgical training may be difficult, as the proportion of TJR cases due to IA is declining. Further research is needed to assess the effect of biologic medications, first introduced in 1998, on IA TJR rates.
T. J. Pan,
S. L. Lyman,
M. P. Figgie,
L. A. Mandl,
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ACR Meeting Abstracts - https://acrabstracts.org/abstract/trends-in-us-arthroplasty-rates-1991-2005-patients-with-inflammatory-arthritis-continue-to-require-joint-replacement/