reports

Complications following total joint arthroplasty in patients with rheumatoid arthritis

Toronto, ON, Canada: University of Toronto (doctoral dissertation).

University of Toronto, Toronto, ON, Canada

BACKGROUND: Total joint arthroplasty (TJA) is indicated in persons with end-stage arthritis of the hip and knee (THA and TKA, respectively). While most TJAs are performed for osteoarthritis (OA), 3%-13% are performed in patients with rheumatoid arthritis (RA). Most of the evidence regarding complications following TJA is based on studies of patients with OA. Comparatively little is known about outcomes of TJA in patients with RA. The purpose of this thesis was to summarize current evidence on the rates of complications following TJA in patients with RA, to quantify the risk of complications using validated methods, and to determine the impact of surgeon experience performing TJA in persons with RA on this risk.

METHODS: For reports published between 1990 and 2011, we evaluated the evidence regarding the risk of complications following TJA in persons with RA using qualitative and, when feasible, quantitative methods. In a cohort of recipients of primary elective THA or TKA between 2002 and 2009, in Ontario, Canada, we identified patients with RA using a validated administrative data algorithm. Multivariable Cox proportional hazards regression was used to evaluate the relationship between arthritis type (RA, OA, other) and the occurrence of pre-specified surgical complications, and to evaluate the impact of surgeon experience (defined as the number of TJAs performed in patients with RA in the preceding year) on the risk of a complication.

RESULTS: Forty published studies were reviewed. Relative to TJA recipients with OA, those with RA were found to be at increased risk of dislocation following THA, and increased risk for joint infection following TKA. These findings were confirmed in our cohort study: adjusted hazard ratio (HR) for dislocation 1.91, p=0.001; adjusted HR for infection 1.47, p=0.03). In TJA recipients with RA, greater surgeon RA volume, but not overall TJA volume, was associated with a reduced risk for surgical complications (adjusted HR per 10 additional cases: RA volume 0.81, p=0.002; overall volume: 0.98, p=0.09).

CONCLUSIONS: In a population-based cohort of primary elective TJA recipients, patients with RA were at significantly increased risk for dislocation following THA and joint infection following TKA. Increased surgeon experience performing TJA in patients with RA attenuated the risk for surgical complications among TJA recipients with RA, a potentially modifiable risk factor. Further research is required to identify the mediators of the increased complication risk in patients with RA, and to delineate strategies to optimize outcomes in these patients.