The two main options
General anaesthesia You're given medication through an IV that puts you into a state of controlled unconsciousness for the procedure, with your breathing supported by a device placed in your airway. You're not aware of the surgery and don't feel it taking place.
Spinal (regional) anaesthesia A fine needle is used to place numbing medication in the lower spine, which numbs the lower half of the body for the duration of the procedure and for some hours afterward. Many patients are also given light sedation alongside a spinal so they're relaxed or asleep during surgery, without needing a breathing tube.
Comparing the two
Both options are well established for knee replacement, and your anaesthesiologist's recommendation will be based on your individual health profile, including factors like heart and lung health, medications, and prior anaesthetic experience.
Some general considerations, though individual circumstances vary:
- General anaesthesia involves airway support during surgery and a period of grogginess as the medication wears off afterward.
- Spinal anaesthesia avoids a breathing tube and can mean being more alert soon after surgery, but involves numbness in the legs for some hours, and mobility (including getting up and starting rehabilitation) needs to wait until normal sensation returns. There's a small chance of a post-procedure headache, and men with prostate conditions in particular can have temporary difficulty passing urine afterward.
Neither option is universally "better", the right choice depends on your health, the surgical plan, and your anaesthesiologist's clinical judgement on the day.
Pain control beyond the anaesthetic
Alongside general or spinal anaesthesia, additional pain-control techniques, such as targeted local anaesthetic delivered around the knee, or nerve blocks that numb specific nerves supplying the leg, may be used to help manage pain in the hours and days after surgery. Your anaesthesia team will discuss what's planned for you specifically.
What happens on the day
Your anaesthesiologist will confirm the plan with you on the day of surgery, taking into account any changes in your health since your pre-admission assessment. You'll have the opportunity to ask questions and raise any concerns before proceeding.
This article is general information and doesn't replace a consultation. The anaesthesia used in your surgery is determined by your anaesthesiologist in consultation with you.
This page provides general information about a medical condition and a surgical procedure. It is not individual medical advice and does not replace consultation with a qualified practitioner. Outcomes vary between individuals and all surgery carries risk. A referral is needed for a consultation with Professor Daevyd Rodda; without one, you can start with the practice nurse practitioner, who can provide it.