What to Expect on the Day of Knee Replacement Surgery

On the day of knee replacement surgery you are usually admitted in the morning, have the operation under a general or spinal anaesthetic in about 1 to 2 hours, and often take your first steps the same day. It is a well-rehearsed routine for the hospital, even though it is a huge day for you, and knowing the running order removes a lot of the fear¹.

The day itself frightened me more than it should have, mostly because I did not know the sequence of events. Once a nurse walked me through it, I felt calmer. So here is that walk-through, checked by a consultant orthopaedic surgeon. If you have not yet prepared, read preparing for knee replacement surgery first, and for the operation in context see knee replacement surgery.

Admission and getting ready

You will usually be admitted on the morning of surgery, having fasted as instructed (typically no food for several hours beforehand). A nurse checks you in, and you meet your surgeon and anaesthetist, who confirm the plan, answer questions, and take your consent. The surgeon often marks the correct leg. You change into a gown and compression stockings, and the team runs final checks. National guidance such as NICE NG226 supports this as planned, shared-decision surgery, so the consent conversation is a genuine chance to ask anything still on your mind².

The anaesthetic

Your anaesthetist will use either a general anaesthetic (you are fully asleep) or a spinal anaesthetic (you are numb from the waist down, often with light sedation so you are comfortable and unaware). They will discuss which suits you best on the day, taking your health into account. Either way, you will not feel the operation.

The operation

The operation takes about 1 to 2 hours. In a total knee replacement, the surgeon resurfaces all three compartments of the knee with metal and plastic components; in a partial replacement, only the one damaged compartment is resurfaced, keeping healthy bone and ligaments³. The knee is tested for stability and movement before you are fully awake. With anaesthetic preparation beforehand and recovery-room time after, you will be away from the ward longer than the operation itself.

Recovery room and the ward

You wake in the recovery area, where staff monitor you closely, then return to the ward. Early pain is expected once the anaesthetic wears off, and it is managed with regular medication, often started before you feel it⁴. To prevent blood clots, you will be given blood thinners, compression, and encouragement to move. Tell staff if your pain is not controlled, because good early pain relief is what lets you start the exercises.

Taking your first steps

Many people take their first steps with a physiotherapist the same day or the day after surgery, using a frame. This is sooner than most expect and it can feel daunting, but early movement helps prevent clots and starts your recovery, with bending the knee the key early goal¹. I remember being amazed and a little terrified to be standing on the new knee within hours; it wobbled, but it held. Our knee replacement recovery timeline covers what comes next.

How long you stay

Most people stay in hospital 1 to 3 days, and some centres now carry out day-case knee replacement in selected, fitter patients. You go home once your pain is controlled, you can move safely with your aids, and the team is happy with your wound and general recovery. From there, the real work of physiotherapy and regaining your bend begins, which we cover in regaining knee bend and avoiding stiffness.