Techniques · Both joints
Bilateral Joint Replacement — is doing both at once safe?
If both hips (or both knees) are worn out, you may be a candidate for bilateral surgery — simultaneously (one operation, one anaesthetic) or staged (one side first, the other weeks to months later).
The benefits — for suitable patients
One operation, one recovery.
One anaesthetic
A single trip to the operating room, not two.
One hospital stay
One admission, one discharge.
One recovery period
One block of rehab instead of two.
Faster return to full function
Both sides progress together.
Lower combined cost
One operative episode is more efficient.
Both sides fixed together
Neither leg holds the other one back.
Especially helpful when both sides are equally bad and recovering one side is held back by the other.
Two paths
Simultaneous vs staged
Both joints, one operation
- One anaesthetic, one hospital stay
- One recovery and rehab period
- Fastest overall return to full function
- Lower combined cost
- Best for younger, healthier patients with good heart & lung function
One side now, the other later
- Spreads the stress across two smaller operations
- Safer route if you aren't an ideal candidate for simultaneous
- Two recoveries and two rehab periods
- Second side is planned weeks to months later
- You still get both joints done — just separately
An honest look
Is it safe?
For carefully selected, healthy-enough patients — yes. In well-matched patients, simultaneous bilateral hip or knee replacement has complication and mortality rates comparable to doing them separately.
For the hip — particularly with the anterior approach — selected patients do very well: short stays, most going home quickly, and low rates of infection, dislocation and clots. Some studies even show fewer clots and chest complications than staged.
Why selection matters
Doing both at once puts more stress on the body — more blood loss, more strain on the heart and lungs — than one side alone. In patients who aren't ideal candidates, doing both at once can carry higher early risks. That's exactly why candidates are chosen carefully.
Am I a candidate? — a starting point
Tick the ones you think apply to you. This isn't a decision — it's a starting point for the conversation with your surgeon and anaesthesia team, who make the final call.
The more of these that apply, the more likely simultaneous is a safe option. Even if only some apply, staged surgery is a great alternative that still gets both joints done.
A shared decision
The decision to do both at once, stage them, or start with one side is a shared decision based on how bad both sides are, your overall health, and a safety assessment by your surgeon and anaesthesia team.
⚖️ Remember — everyone's different: your surgeon and anaesthesia team will advise whether simultaneous bilateral surgery is safe for you.
References
Knee: In carefully selected patients, simultaneous bilateral TKA has complication/mortality rates comparable to staged (integrated registry ~11,000 patients: death 0.28% vs 0.1%; adverse events 2.49% vs 1.97%, J Arthroplasty, PMID 27430183; selected single-institution series, The Knee 2023). In unselected patients it carries higher early mortality and cardiac/clot risk (meta-analysis, PMC3640720; 567,915-patient meta-analysis 2025, PMC12548196 — lower reoperation and cost but higher complications/mortality; selection essential). About one-third of knee-arthritis patients have both knees affected.
Hip: Simultaneous bilateral THA is safe in selected patients, with a meta-analysis showing lower DVT, PE and respiratory complications than staged (PMID 31574793 / PMC6775426). Direct-anterior-approach simultaneous bilateral THA in selected patients shows low complications, short stay and high home-discharge (PMID 34192915; SICOT-J 2024, PMID 39177435). An 82,897-patient analysis found both approaches viable, with simultaneous patients typically younger, healthier and lower-ASA (PMC12543236).
Patient selection (younger, healthier, lower ASA, good heart/lung status) is the key to safety.