Elective primary total hip arthroplasty in rheumatoid arthritis versus osteoarthritis: in-hospital outcomes from the national inpatient sample, 2016–2021
Archives of Orthopaedic and Trauma Surgery · 7 Oct 2026
† Impact is the editorial-priority score. All scores are out of 100. Clinical is a stored clinical-importance score from the earlier method; it has not been recalculated.
Why it matters
Patients with RA having hip replacement may need closer attention to blood management, kidney protection, and discharge planning, although the absolute excess risk is small.
The evidence
Using a large US national inpatient database (2016 to 2021), the authors compared 7,264 elective primary hip replacement admissions in patients with a rheumatoid arthritis (RA) code against 267,275 admissions for primary hip osteoarthritis (OA), adjusting for baseline differences with propensity-score weighting. RA was associated with modestly higher odds of in-hospital complications, for example a composite of blood loss anaemia, transfusion, or acute kidney injury (23.8% vs 18.2%, OR 1.31, 95% CI 1.24 to 1.39), plus more non-home discharge and a length of stay about 0.14 days longer. Absolute differences were small, and residual imbalance between groups persisted after weighting.
Composite hematologic/renal in-hospital complication: Odds ratio 1.31 (95% CI 1.24 to 1.39; ratio). Interpret in the study's stated comparison; this alone does not establish a treatment's causal effect.
Why this rigour score?
Registry cohort (adjusted)Design starting point: 37.4
Raised the score
- Aligned time zero+2.5
- Compared against an accepted alternative+1.7
Lowered the score
- Important imbalance remained after adjustment−5.1
Methods at a glance
Recorded assessment- Confounding adjustmentInverse-probability weighting / doubly robust
- Covariate balance confirmedNot met
- Outcome assessors blindedNot reported
- Comparable start of follow-upMet
- Adequate statistical powerNot reported
- Prospective registrationNot met
Not reported does not mean not done. Checks have different weights; this is not a count of boxes ticked.
See the full score breakdown
- Study design starting point
- 37.4
- Important imbalance remained after adjustment
- −5.1
- Aligned time zero
- +2.5
- Compared against an accepted alternative
- +1.7
- Journal prior (not an observed method)
- +1.4
- Final rigour score rounded
- 38 / 100
Study design sets the starting point and a ceiling of 80. Recorded methods then adjust the score. Points are shown to one decimal place; the final score uses unrounded values.
Checklist from the stored appraisal. “Not met” describes the recorded criterion; it does not always produce a deduction. This overview supports reading the full study.
For journal club
1.Given the higher odds of blood loss anaemia and transfusion in RA patients, which preoperative blood-management steps (anaemia screening, iron, tranexamic acid) would you prioritise for an RA patient scheduled for THA?
2.How would you counsel a patient with RA about their expected hospital stay and the chance of discharge to a facility rather than home after elective THA?
Original publication title
Elective primary total hip arthroplasty in rheumatoid arthritis versus osteoarthritis: in-hospital outcomes from the national inpatient sample, 2016–2021