Continuing or Holding a TNF Inhibitor Before Elective Knee Replacement
A joint implant raises the stakes of any infection risk, but the guideline built to manage that risk asks for less caution than the surgeon's own instinct expects, on both drugs in play.
Samuel P., a 66-year-old man, spends most of his free time since retiring from a long career in accounting volunteering at the community center, preparing tax returns for seniors who can't afford to pay for the service. His rheumatoid arthritis, fifteen years old, has been well controlled on adalimumab and methotrexate for most of that time — his DAS28-CRP has held at 2.3, solid remission, for years now — but the joint damage it caused before that control was reached has left his right knee bone-on-bone, and he is scheduled for a total knee arthroplasty in three weeks.
The 2022 ACR/AAHKS perioperative guideline, developed jointly by rheumatologists and orthopedic surgeons specifically to settle exactly this decision, recommends holding a biologic like adalimumab for one dosing interval before elective surgery, timed so the next scheduled dose simply isn't given rather than an extended washout being enforced — and, in a finding that runs against older, more cautious instinct, recommends continuing methotrexate at its usual dose right through surgery, since stopping it has not been shown to lower infection or wound-healing complication risk and does carry a real risk of a postoperative flare. Adalimumab's own pharmacokinetics support the guideline's specific choice of interval: with a half-life of roughly two weeks, most of the drug already clears the body by the time the next dose would ordinarily be due, meaning a longer hold buys little additional reduction in circulating drug while giving up real disease control. None of that changes what's actually at stake if an infection does take hold in a joint that now has permanent hardware in it — a periprosthetic joint infection is a different order of complication than an infected incision that heals with antibiotics, which is precisely why his surgeon wants more margin than the guideline specifies. Read against his own risk profile, though, some of that margin is already banked: no diabetes and no obesity, both established drivers of periprosthetic infection risk, and a first arthroplasty rather than a revision, which itself carries a materially lower infection rate than reopening an already-operated joint.
Deciding the perioperative medication plan
I'd want a longer hold on the adalimumab than one dosing interval, and I'd still feel more comfortable stopping the methotrexate too. A periprosthetic joint infection isn't like an infected incision that clears with antibiotics — it can mean removing the implant entirely. That's a different order of consequence than most surgical-site infections, and I'd rather have more margin than less going into it.
I understand the instinct, but the 2022 ACR/AAHKS guideline was built jointly by rheumatologists and orthopedic surgeons specifically to settle this question, and it recommends holding adalimumab for exactly one dosing interval — not longer — and continuing methotrexate at his usual dose right through surgery. That second part runs against the older instinct too, but the evidence behind it is real: continuing methotrexate hasn't been shown to raise infection or wound-healing complication risk, and stopping it does carry a genuine flare risk.
The guideline's interval isn't an arbitrary compromise between your concern and mine — it reflects the actual evidence available on infection risk at different hold durations, which hasn't shown further benefit from extending the hold beyond one interval. A longer hold trades real disease control for a margin the data don't support.
I'd add the pharmacokinetic case for why one interval is the right number rather than an arbitrary guideline choice. Adalimumab has a half-life of roughly two weeks, so by the time his next scheduled dose would be due, most of the drug is already cleared from his system. Holding it further past that point doesn't meaningfully reduce his circulating drug level any further — it just adds unprotected time with active disease, without buying additional infection-risk reduction.
Agreed: adalimumab held for one dosing interval before surgery per the guideline, with methotrexate continued unchanged throughout, and the next adalimumab dose resumed once the surgical wound is healing appropriately.
Not agreed: the surgeon remains uneasy about the margin, and said so directly, agreeing to the plan on the strength of the guideline's evidence base rather than being fully persuaded that one interval is enough for a patient of his own. Where the evidence would tip if his risk profile were higher — obesity, diabetes, or a revision rather than primary arthroplasty — was raised and left unresolved, since none of those apply to him.