As you recover, it can be difficult to know what is normal and what may require medical attention. Below is a guide to help you through your recovery. If you have any concerns, please contact Dr Tim Roberts' office.
Common Side Effects After Knee Replacement Surgery
The following are common after knee replacement surgery and usually improve as you recover.
Swelling: Mild swelling of your knee, leg or foot is common. Elevating your leg and using ice will help reduce swelling.
Pain: Some discomfort is expected and can usually be managed with your prescribed pain medication.
Bruising and Warmth: Bruising, warmth and tenderness around the incision are normal.
Clicking Sounds: Your new knee may click or make noises during movement. This is common and normal.
Numbness: Temporary numbness around the incision is common.
Drainage: A small amount of blood or yellow fluid on your dressing is normal.
Mild Fever: A one-off temperature during the first few days after surgery can occur.
Seek Urgent Medical Attention if You Experience:
Increasing Redness: Redness spreading beyond your incision.
Persistent Fever: Ongoing fever or feeling generally unwell.
Excessive Bleeding or Discharge: Heavy bleeding or significant fluid leaking from the wound.
Severe Swelling: Marked swelling in your leg that does not improve with elevation.
Shortness of Breath or Chest Pain: These may indicate a serious complication.
Dizziness or Racing Heart: Feeling faint, dizzy or unwell with a fast heart rate.
Severe Pain: Pain that is not controlled by your prescribed medication.
Wound Care
Waterproof Dressing: Leave your dressing in place until your wound check at approximately two weeks.
Keep it Clean and Dry: Keep the dressing dry for the first 48 hours.
Showering: After 48 hours you may shower, provided the dressing remains intact. Pat it dry afterwards.
Avoid Soaking: Do not swim, use a spa or have a bath until your wound has completely healed.
Dressing Problems: If your dressing comes off early or becomes heavily soaked with blood or fluid, contact Dr Tim Roberts' office
Driving
After Surgery: You cannot drive on the day of surgery and will need someone to drive you home.
Crutches: Do not drive while using crutches.
General Guidelines
Left knee replacement: You may drive an automatic vehicle after approximately 3 weeks, provided you feel safe and have checked your insurance policy.
Right knee replacement: Wait approximately 6 weeks before driving.
Flying
Domestic Travel (NZ): If you have travelled to Auckland for surgery, you will require an Air New Zealand medical certificate before flying home. If you need to fly within two weeks of surgery for any other reason, please contact Dr Tim Roberts' office.
Australia & Pacific: Wait at least 6 weeks after surgery.
International Travel: Wait approximately 3 months after surgery.
Long-distance Travel: Long car trips and flights increase your risk of blood clots (DVT). Discuss any travel plans with Dr Tim Roberts before travelling.
Return to Work
This varies depending on the type of work you do but a general guideline is:
Sedentary Jobs: You may return to work in 2-4 weeks.
Physical Jobs: It will take about 6-8 weeks for a safe return.
Sleeping
Sleep Discomfort: It’s common to experience sleep issues in the first 6-12 weeks while healing
Pain Management at Night: Endorphins, which naturally reduce pain, decrease during sleep, so the hip and leg may ache. Take prescribed medication at night to manage pain. Remain active during the day and use heat packs if they help.
Normal Sleep: Sleep should improve as your hip heals.
Medications
Blood Thinners & Medications: Follow Dr. Roberts’ instructions for blood thinners and any other prescribed medications.
Pain and Anti-inflammatory Medications: These are often needed for the first 10 days, but you can gradually reduce their use as you recover.
Around the House
Use the handrail on stairs.
Remove loose rugs to avoid tripping
Wear supportive footwear.
Keep frequently used items within easy reach. If you live in a multi-storey house arrange frequently used items on the one level.
Continue using your walking aids until advised otherwise.
Ice your knee after activity if it becomes swollen.
Nonslip shower mat and decals inside and outside the shower.
Airports
Security Screening: Your knee replacement may set off airport metal detectors. Simply let security staff know before you pass through screening.
Stages of Recovery
Phase 1: Weeks 0–2
Your Goals
Walk safely
Reduce swelling
Fully straighten your knee
Wake up and strengthen your thigh (quadriceps) muscle
What to Expect
During the first 12–24 hours, your knee is still benefiting from the local anaesthetic used during surgery, so discomfort is often quite manageable.
Your nursing staff and physiotherapist will help you get out of bed and start walking on the day of surgery or the following morning.
Early movement helps:
Reduce the risk of blood clots
Improve knee movement
Activate your muscles
Make everyday activities easier
You can place full weight through your operated leg immediately unless your surgeon advises otherwise.
Most patients stay in hospital for 2–3 nights.
It is normal for pain, swelling and stiffness to increase during the first few days. Continue taking your prescribed medications, icing your knee regularly and completing your exercises.
Exercises
The most important goal during the first two weeks is achieving full knee straightening.
To help:
Never rest with a pillow under your knee.
Instead, place a pillow under your calf or ankle.
Tighten your thigh muscles by pressing the back of your knee into the bed.
Pump your ankles regularly to improve circulation.
Practice bending your knee until you feel a gentle stretch.
Hold each stretch for around 30 seconds before relaxing.
Little and often is better than trying to do too much at once.
Phase 2: Weeks 2–6
Your Goals
Walk further each day
Gradually stop using crutches
Improve knee movement
Build strength
What to Expect
Continue taking several shorter walks throughout the day rather than one long walk.
Aim for walks of 10–15 minutes, gradually increasing your distance as your comfort improves.
A stationary bike is an excellent exercise during this stage.
Start with:
A high seat position
Low resistance
5–10 minutes
Gradually increase your cycling time as your strength improves.
By six weeks, most patients aim for:
Full knee straightening (0°)
At least 100° of knee bending
Helpful Exercises
Heel slides
Straight leg raises
Wall squats
Shallow lunges
To improve straightening, rest your heel on a stool and allow gravity to gently straighten the knee.
To improve bending, slide forward in a chair while keeping your foot planted to create a comfortable stretch. Hold stretches for approximately 30 seconds.
Phase 3: Weeks 6–16
Your Goals
Walk further with confidence
Continue strengthening
Improve flexibility
Exercises
Gradually build your stationary cycling up to around 30 minutes each day.
Continue strengthening and stretching exercises, aiming for at least 110° of knee bending.
This will make everyday activities such as walking downstairs, climbing stairs and getting out of low chairs much easier.
Some swelling is still completely normal at this stage, particularly after busy days.
If recommended by your surgeon, anti-inflammatory medication may help reduce discomfort.
Phase 4: Months 4–18
Returning to Normal Activities
By this stage, most patients have returned to their normal daily activities with no specific restrictions.
It is still common to notice:
Mild swelling after a busy day
Occasional aching at night
Some discomfort when kneeling
These symptoms often continue to improve for many months after surgery.
Your scar will also continue to soften and mature over the next year or more.
Kneeling is safe once your knee is comfortable enough, and regular scar massage can help reduce sensitivity over time.