Total Knee Replacement Surgery: Postoperative Care and Rehabilitation

Purpose and rationale: Use the walker to practise short, steady steps without sudden stress on the knee.

Phase and starting criteria: After weight bearing has been permitted and once dizziness and nausea are controlled.

Equipment and safety: A walker adjusted to wrist-crease height, closed shoes, and a dry surface; have someone beside you for the first sessions.

Starting position: Stand inside the walker frame with the elbows slightly bent. Share weight through your hands and legs as instructed at discharge.

How to do it:

1. Place the walker one short step ahead and make sure all four legs/wheels are stable.
2. Move the operated leg forward to the middle of the walker and gently place the heel down.
3. Using your hands and the operated leg for support, bring the non-operated leg forward.
4. Take several small steps to turn; do not twist on one foot.

Range, side, and limits: Keep steps short and avoid dragging the toes; bear only the amount of weight written in your discharge instructions.

Breathing, speed and rhythm: Breathe freely and calmly repeat the sequence “walker, operated leg, non-operated leg.”

Amount and repetitions: Walk for five minutes during each waking hour. At first, divide this time into shorter sessions if needed. Increase it only if pain, swelling and limping have not increased by the next morning.

Rest: Rest between exercise sessions as directed by your physiotherapist. Do not continue when fatigue changes your movement technique.

Expected response: Sit and elevate the leg between sessions. Mild fatigue is normal; sharp pain or dizziness is not.

Signs of correct performance: The walker is stable, your trunk faces forward, and both feet remain inside the frame.

When to stop: Stop if you develop sharp knee pain, dizziness, giving way, or cannot keep within your weight-bearing limit. Also stop if you experience feeling faint, chest pain, shortness of breath, the knee giving way, or sharp pain.

Common errors: Pushing the walker too far ahead, hanging heavily through the arms, taking long steps, and pivoting on the operated leg.

Easier version: Use a shorter route with a helper and take more rest.

Progression criteria: Progress to a cane only when you can walk without heavy support, without giving way, and without a limp.

1. 1. Walker forward
2. 2. Left foot forward
3. 3. Right foot follows

“Left” identifies this character’s operated leg. This teaching marker does not mean a dressing is still needed. Read the frames from left to right.

Purpose and rationale: Moving the ankle keeps your calf muscles active and supports circulation while you are less mobile.

Phase and starting criteria: From the first hours, once you are alert and the care team has permitted the movement.

Equipment and safety: A bed or firm chair; if sensation has not fully returned to the leg, perform the movement under supervision.

Starting position: Lie on your back or sit semi-reclined, with the calf supported and the heel on a short support so that the ankle and toes are free; keep the thigh and knee facing the ceiling.

How to do it:

1. Keep the knee and thigh still.
2. Gently pull the toes toward your face.
3. Then point the toes away from you.
4. Repeat continuously without rotating the whole leg.

Range, side, and limits: Move both ankles through a comfortable range; do not force the end of the range.

Breathing, speed and rhythm: Breathe freely and move slowly, at about one complete back-and-forth movement every 2 seconds.

Amount and repetitions: After discharge, use your own plan for session duration, repetitions and frequency. Different guideline schedules are explained in the scientific notes at the end.

Rest: Rest between exercise sessions as directed by your physiotherapist. Do not continue when fatigue changes your movement technique.

Expected response: Mild calf fatigue is expected and should settle with a short pause.

Signs of correct performance: Only the ankle moves.

When to stop: Stop if calf pain or cramp does not settle with a brief pause, one calf becomes swollen or tight, or the foot develops new numbness. Also stop if you experience new calf pain or tightness, one-sided swelling, shortness of breath, or chest pain.

Common errors: Moving too quickly, rotating the whole leg, holding your breath, and pushing into pain.

Easier version: Use a smaller range and a slower rhythm.

Progression criteria: Continue this exercise during prolonged sitting; do not add resistance, and make safe increases in walking the next stage.

1. 1. Toes toward shin
2. 2. Toes away from shin

Purpose and rationale: Tighten the muscle at the front of your thigh without a large knee movement to improve control and straightening.

Phase and starting criteria: Once pain allows a gentle contraction.

Equipment and safety: A flat surface; do not place pressure on the wound or use a weight.

Starting position: Lie on your back with the operated leg facing the ceiling, the heel on the surface, and a small rolled towel beneath the back of the knee.

How to do it:

1. Keep the toes pointing toward the ceiling.
2. Tighten the muscle at the front of the thigh.
3. Gently move the back of the knee toward the surface without lifting the heel.
4. Hold for 5 to 10 seconds, then release fully.

Range, side, and limits: No large joint movement is needed; keep the pelvis and non-operated leg still.

Breathing, speed and rhythm: Breathe out as you tighten the muscle and breathe normally between repetitions.

Amount and repetitions: Hold each contraction for 5 to 10 seconds; complete about 10 repetitions over 2 minutes, rest for 1 minute, and then complete another round if you can maintain good form. [3]

Rest: Rest between exercise sessions as directed by your physiotherapist. Do not continue when fatigue changes your movement technique.

Expected response: Mild tension at the front of the thigh is normal; the knee should not become more swollen afterward.

Signs of correct performance: The quadriceps becomes prominent or the kneecap moves slightly.

When to stop: Stop if pain develops inside the joint rather than a stretch in the thigh, or knee swelling increases after the session. Also stop if you experience sharp pain, increased wound drainage, or a persistent cramp.

Common errors: Pushing with the buttocks, lifting the heel, holding your breath, and tightening the non-operated leg instead of the operated leg.

Easier version: Use a 2- to 3-second contraction with tactile feedback, or NMES under a physiotherapist’s supervision.

Progression criteria: Once you can clearly tighten the front thigh muscle, begin a straight-leg raise with your therapist’s agreement; the knee must stay straight during the lift.

1. 1. Static position
2. 2. Close-up of same position

Purpose and rationale: This stretch helps your knee straighten, which supports walking and the work of your thigh muscles.

Phase and starting criteria: When permitted by the care team and there is no sharp pain behind the knee.

Equipment and safety: A rolled towel or firm pillow only beneath the heel; do not place a weight or hand pressure on the knee.

Starting position: Lie on your back with the heel of the operated leg on the support and the entire back of the knee and upper calf unsupported.

How to do it:

1. Keep the toes pointing toward the ceiling.
2. Relax the thigh and buttock.
3. Allow the weight of the lower leg to gently straighten the knee.
4. To finish, use the non-operated leg or a hand under the calf to help lower the leg.

Range, side, and limits: Continue only to a mild stretch; do not force the knee against the bed, and do not place a pillow behind the knee itself.

Breathing, speed and rhythm: Breathe slowly, without protective muscle tightening; this is a static position with no bouncing.

Amount and repetitions: AAOS does not specify one duration for this stretch; obtain the duration and frequency from your physiotherapy plan and begin with a short, tolerable session.

Rest: Rest between exercise sessions as directed by your physiotherapist. Do not continue when fatigue changes your movement technique.

Expected response: The stretch behind the knee should settle within a few minutes after you finish.

Signs of correct performance: The heel is supported and the back of the knee is free.

When to stop: Stop if sharp pain develops behind or inside the knee, or the stretch does not settle within a few minutes after finishing. Also stop if you experience sharp pain, persistent tingling, or a clear increase in swelling.

Common errors: Placing the support under the knee itself, adding a weight, turning the toes outward, and tolerating pain for too long.

Easier version: Use a lower support and less time; do not change the support height in the middle of a session.

Progression criteria: As the back of the knee gradually approaches the surface without increased pain or swelling, practise keeping the knee straight during standing and walking with your therapist’s advice.

1. 1. Support under heel only

Purpose and rationale: Slide the heel slowly to practise bending the knee for sitting, transfers and stairs.

Phase and starting criteria: Once the wound is protected and movement does not cause sharp pain.

Equipment and safety: A flat bed and, if needed, a towel beneath the foot; avoid suddenly pulling with a strap.

Starting position: Lie on your back with both legs facing the ceiling and the heel of the operated leg on the surface.

How to do it:

1. Slowly slide the heel toward your buttock.
2. Keep the knee aligned with the second toe.
3. Pause for 5 to 10 seconds at a tolerable stretch.
4. Slowly slide the heel forward until the knee is straight again.

Range, side, and limits: Move only to a mild stretch without lifting the pelvis; 90 degrees is not a mandatory target in the first week.

Breathing, speed and rhythm: Breathe out while bending and in while returning; keep each back-and-forth movement slow.

Amount and repetitions: A common target is 3 sets of 10 repetitions with a hold of about 5 seconds. In the first days, start with one shorter set and build to this amount only if pain and swelling have not increased by the next morning. [7]

Rest: Rest between exercise sessions as directed by your physiotherapist. Do not continue when fatigue changes your movement technique.

Expected response: A stretch at the front of the knee or thigh is expected and should settle quickly.

Signs of correct performance: The heel glides along a straight line.

When to stop: Stop if you feel sharp joint pain, painful catching, have to lift your pelvis to bend further, or the stretch does not settle promptly. Also stop if you experience sharp pain, catching, wound opening, or new drainage.

Common errors: Letting the knee fall inward, lifting the pelvis, using a bouncing movement, and holding a painful position for too long.

Easier version: Use a shorter range or gentle assistance from the non-operated leg.

Progression criteria: Increase range only if the knee returns to its settled baseline before the next session; the next stage is functional flexion during sitting.

1. 1. Start with leg straight
2. 2. Slide the heel
3. 3. Pause at comfortable bend

Purpose and rationale: This exercise strengthens the front of the thigh and helps the knee stay straight while you lift the leg.

Phase and starting criteria: Only when you can keep the knee completely straight without an “extension lag.”

Equipment and safety: A flat bed, without a weight; if the knee bends as you lift, it is not yet time for this exercise.

Starting position: Lie on your back with the non-operated leg bent and its foot on the bed; keep the operated leg straight with the toes facing the ceiling.

How to do it:

1. Tighten the quadriceps of the operated leg.
2. Keeping the knee straight, raise the leg about 20 to 30 cm.
3. Hold for up to 5 seconds only if the knee remains straight.
4. Lower the leg slowly and with control onto the bed, then relax the muscle.

Range, side, and limits: Use only the operated leg; greater height is not the goal, and the lower back should not arch.

Breathing, speed and rhythm: Breathe out while lifting and in while lowering; take at least 2 seconds to lower the leg.

Amount and repetitions: A common target is 3 sets of 10 repetitions with a 5-second hold; begin with 1 set of 5 to 10 repetitions and increase the volume only while maintaining a straight knee. [7]

Rest: Rest between exercise sessions as directed by your physiotherapist. Do not continue when fatigue changes your movement technique.

Expected response: Fatigue at the front of the thigh is normal; joint pain or increased swelling is not.

Signs of correct performance: The heel and knee rise together, and the knee does not bend.

When to stop: Stop if joint pain or swelling increases, or you need to arch your back to lift the leg. Also stop if you experience an extension lag, sharp groin or back pain, or obvious swelling.

Common errors: Lifting before tightening the quadriceps, bending the knee, holding the breath, and swinging the leg.

Easier version: Perform only the quadriceps contraction, or have a physiotherapist assist the start of the lift.

Progression criteria: Complete 10 repetitions without an extension lag; then add sets, followed by seated strengthening with the therapist’s permission.

1. 1. Start on bed
2. 2. Lift with knee straight

Purpose and rationale: Practise sitting down and standing up safely while strengthening the muscles used in everyday activities.

Phase and starting criteria: Once standing with a walker and weight bearing are safe.

Equipment and safety: A firm, fairly high chair with armrests, a walker in front, and a helper at first; do not use a chair with wheels.

Starting position: Sit near the edge of the chair with both feet on the floor, the operated leg slightly forward, and your hands on the armrests.

How to do it:

1. Lean your trunk slightly forward from the hips.
2. Push through the chair’s armrests; do not pull on the walker.
3. Stand with the knees aligned, then place your hands on the walker.
4. To sit, step back until you feel the chair, place your hands on the armrests, and lower yourself slowly.

Range, side, and limits: Both legs should contribute; do not let the operated knee fall inward.

Breathing, speed and rhythm: Breathe out while standing and in while sitting; keep the lowering movement controlled.

Amount and repetitions: APTA recommends functional sit-to-stand training but does not specify one dose; the physiotherapist should determine the number of sets and repetitions based on chair height, the need for hand support, and movement quality.

Rest: Rest between exercise sessions as directed by your physiotherapist. Do not continue when fatigue changes your movement technique.

Expected response: Thigh fatigue is normal; increased limping or swelling indicates that the number was too high.

Signs of correct performance: The chair is stable, the knees remain aligned, and the movement is smooth.

When to stop: Stop if the knee falls inward, you need to pull yourself up, or limping and swelling increase afterwards. Also stop if you experience the knee giving way, dizziness, or sharp pain.

Common errors: Pulling on the walker, dropping onto the chair, bringing the feet too close together, and pushing only through the non-operated leg.

Easier version: Use a higher chair, a firm cushion, or help from another person.

Progression criteria: Reduce hand assistance while maintaining symmetry and sitting control; then use a chair closer to a standard height.

1. 1. Start seated
2. 2. Push on chair arms
3. 3. Stand, then take walker

Purpose and rationale: This exercise strengthens the calf muscles and helps control standing and stepping forwards.

Phase and starting criteria: Once you can stand with symmetrical weight and light support.

Equipment and safety: A fixed counter or rail and closed shoes; the back of a lightweight chair is not a fixed support.

Starting position: Stand with the feet hip-width apart, both hands near the support, and the knees nearly straight but not locked.

How to do it:

1. Share your weight across the forefoot of both feet.
2. Slowly raise both heels by the same amount.
3. If balance remains steady, hold for up to 5 seconds.
4. Slowly lower both heels to the floor.

Range, side, and limits: Perform bilaterally through a controlled range; do not let the body sway forward and backward.

Breathing, speed and rhythm: Breathe out while rising and in while lowering; take 2 seconds up and 2 seconds down.

Amount and repetitions: A common target is 3 sets of 10 repetitions with a hold of about 5 seconds; begin with fewer sets and rest between them until your form returns. [7]

Rest: Rest between exercise sessions as directed by your physiotherapist. Do not continue when fatigue changes your movement technique.

Expected response: Mild burning in the calf muscles is normal and should settle with rest.

Signs of correct performance: Both heels rise together and the trunk remains upright.

When to stop: Stop if you lose balance, your body sways, or calf cramp does not settle with rest. Also stop if you experience one-sided calf pain, dizziness, or instability.

Common errors: Bending the knees, bouncing upward, transferring weight only to the non-operated leg, and gripping the support tightly.

Easier version: Rise through a smaller height and use more hand contact.

Progression criteria: Complete 3 symmetrical sets without swaying; then reduce hand contact rather than progressing to single-leg heel raises without an assessment.

1. 1. Heels on floor
2. 2. Both heels rise

Purpose and rationale: This movement strengthens the front of the thighs and hips using both legs.

Phase and starting criteria: Once symmetrical standing, balance, and knee control are adequate.

Equipment and safety: A fixed counter or rail, closed shoes, and a non-slip surface.

Starting position: Stand with the feet hip-width apart, toes facing forward, hands resting lightly on the support, and weight evenly distributed.

How to do it:

1. Move the hips slightly backward.
2. Bend the knees through a small, comfortable range.
3. Keep each knee tracking over the second toe.
4. Push through the feet and return to standing.

Range, side, and limits: Use a shallow, bilateral squat through a comfortable, controllable range; pain or inward knee collapse is the stopping limit, and reaching a specified angle is not the goal at this stage.

Breathing, speed and rhythm: Breathe in while lowering and out while rising; take about 2 seconds for each phase.

Amount and repetitions: A common target is 3 sets of 10 repetitions with a hold of about 5 seconds. In week 3, start with one short set and a smaller range, and progress only if pain, swelling and limping do not increase.

Rest: Rest between exercise sessions as directed by your physiotherapist. Do not continue when fatigue changes your movement technique.

Expected response: Fatigue at the front of the thighs is normal; swelling or next-day pain should not increase.

Signs of correct performance: The heels remain on the floor, the trunk stays controlled, and the knees remain aligned.

When to stop: Stop if knee pain occurs, the knee falls inward, or pain and swelling increase the next day. Also stop if you experience sharp pain, giving way, or reactive swelling.

Common errors: Squatting deeply, allowing the knees to move forward while the heels rise, letting the knees collapse inward, and pulling the body with the hands.

Easier version: Practice weight transfer or a very small bend with more hand contact.

Progression criteria: Maintain knee alignment and a settled joint through the following day; then increase repetitions and later the range, not both at the same time.

1. 1. Start standing
2. 2. Shallow bend

Purpose and rationale: Gentle pedalling lets you practise bending and straightening your knee without sudden pressure.

Phase and starting criteria: Once mounting and dismounting are safe and there is enough flexion to rock the pedals; some protocols place the start in weeks 4 to 6.

Equipment and safety: A stable stationary bike with a high seat; at first, have a physiotherapist check the seat height and how you mount the bike.

Starting position: Sit with the pelvis centered on the seat, trunk upright, and both feet on the pedals; at the lowest point, the knee should be nearly straight but not locked.

How to do it:

1. Begin by slowly rocking the pedals backward and forward.
2. If range allows, complete one full revolution without forcing it.
3. Maintain a smooth, even rhythm.
4. Slow down to stop, and dismount with secure assistance.

Range, side, and limits: Use zero or very low resistance; do not lift the pelvis off the seat to complete a revolution.

Breathing, speed and rhythm: Breathe freely and move slowly, without sudden force at the point of greatest flexion.

Amount and repetitions: Endurance exercise usually begins in weeks 4 to 6 with 5 minutes and low resistance; in later weeks, 5 minutes may be added at a time, and you should be able to pedal for about 20 minutes at the same resistance before increasing it. Your physiotherapist will set your starting time and rate of progression. [7]

Rest: Rest between exercise sessions as directed by your physiotherapist. Do not continue when fatigue changes your movement technique.

Expected response: Sit and rest between sessions. A mild stretch while bending is expected and should settle with rest; if it persists until the next session, do not continue and contact your therapist.

Signs of correct performance: The pelvis remains still and the pedal revolution is smooth.

When to stop: Stop if your pelvis lifts to complete a revolution, the front of the knee hurts, or stretching discomfort does not settle after rest. Also stop if you experience sharp pain, catching, increased limping, or swelling through the next day.

Common errors: Setting the seat too low, adding resistance too early, rocking the pelvis, and forcing a full revolution.

Easier version: Only rock the pedals with the seat set higher.

Progression criteria: First achieve a smooth full revolution without pelvic movement, then increase time, and during month 2 gradually increase resistance.

1. 1. Pedal low
2. 2. Continue the pedal turn

Purpose and rationale: This exercise helps you feel steadier and more confident when standing and walking.

Phase and starting criteria: Once two-legged standing without a limp is safe beside a support; some programs begin this exercise in weeks 4 to 6.

Equipment and safety: A fixed counter, a level floor, and closed shoes; foam or another unstable surface is not needed at this stage.

Starting position: Stand beside the counter with a tall posture and one hand close to the surface; begin with tandem standing, then progress to one leg.

How to do it:

1. Place one foot directly in front of the other and use hand contact for balance.
2. Reduce hand contact to a few fingers.
3. For single-leg standing, shift weight onto the operated leg and lift the non-operated foot only a few centimeters.
4. If you wobble, immediately use the support and return to standing on both feet.

Range, side, and limits: Keep the operated knee slightly soft and aligned; keep your eyes open and the support within reach.

Breathing, speed and rhythm: Breathe naturally, look at a fixed point, and do not hold your breath.

Amount and repetitions: The guide’s target is to hold the balance with eyes open for up to about 30 seconds; begin with a shorter time and hand contact, and have the physiotherapist set the number of sessions according to your safety. [7]

Rest: Rest between exercise sessions as directed by your physiotherapist. Do not continue when fatigue changes your movement technique.

Expected response: Mild muscle shaking is normal; fear, instability, or pain calls for the easier version.

Signs of correct performance: The pelvis stays level and the knee remains over the toes.

When to stop: Stop if you feel unstable or afraid of falling, develop knee pain, or need to grip the support to prevent a fall. Also stop if you experience loss of balance, dizziness, or sharp pain.

Common errors: Moving away from the support, lifting the opposite knee too high, locking the knee, and practicing on a slippery surface.

Easier version: Use a semi-tandem stance with both hands supported, or keep both feet on the floor.

Progression criteria: If you can balance for 30 seconds with eyes open and very little hand contact, begin multidirectional balance in month 3 with your therapist’s advice. Do not close your eyes or use an unstable surface on your own.

1. 1. One foot ahead of other
2. 2. Stand on left leg

Purpose and why it matters: Use gentle towel assistance to practise knee bending for sitting and transfers. Do not pull suddenly or force the knee.

Stage and starting criteria: From week three, once the wound is closed and heel slides are free of sharp pain. [3]

Equipment and environmental safety: A folded towel or a long fabric strap and a flat bed; the pull comes from your hands, never from a weight or another person.

Starting position: On your back, the operated leg straight, the folded towel looped over the ankle or the top of the foot with both ends in your hands.

How to do it:

1. Set the quadriceps gently so the knee is controlled before it moves.
2. Slide the heel along the bed towards the buttock so the knee bends.
3. Use a gentle pull on the towel to add a few degrees, to the edge of stretch and no further.
4. Hold the knee at that maximum point for 5 to 10 seconds.
5. Release the towel and straighten the leg slowly.

Range, side, and limits: Only as far as stretch, never into sharp pain; the knee stays in line with the toes and the pelvis does not rotate. A range restriction written by your surgeon is the limit.

Breathing, speed and rhythm: Breathe out as the knee bends and in as it straightens; the pull is steady, never a jerk.

Amount and repetitions: Hold 5 to 10 seconds and repeat until the leg feels fatigued — about two minutes (AAOS guide).

Rest: Straighten the leg fully between repetitions and let the stretch settle.

Signs of correct technique and expected response: A mild stretch is expected and should ease after releasing. A larger bend after every repetition is not required.

When to stop: Stop if you develop sharp joint pain, a painful clunk, increasing swelling, wound opening or new discharge.

Common mistakes: Pulling in jerks, holding the breath, rotating the pelvis to gain range, and pushing on through pain in the hope of more.

Easier version: Put the towel aside and do heel slides alone, or shorten the hold to three seconds.

Progression criteria: Range improves over two consecutive sessions with no rise in pain or next-day swelling; then use that range in sitting down and standing up.

Expected and adverse responses: Stretch and mild warmth in the knee are expected; new swelling, more stiffness the next morning, or a loss of range means you went too far — ease the pull.

1. 1. Start with knee straight
2. 2. Gentle towel assistance
3. 3. Pause at comfortable range