Knee Replacement

Written by Tele Demetrious, Physiotherapist, BPhysio(Hons)
Reviewed by Brett Harrop, APA Sports Physiotherapist, BPhysio(Hons), MPhysio(Sports Physio)
Updated:

InjuriesKnee InjuriesKnee Replacement

(Also known as Knee Replacement Surgery, Total Knee Replacement, Total Knee Joint Replacement, Total Knee Arthroplasty)

What is a knee replacement?

A knee replacement is a significant surgical procedure that involves removal of a damaged, diseased and poorly functioning knee joint, often due to gradual wear and tear associated with osteoarthritis. This is subsequently replaced with an artificial or prosthetic joint that may be made of metal alloys, ceramic material or strong plastic components.

Knee Replacement Anatomy

The knee joint is a hinge joint that primarily comprises of the union of two bones: the long thigh bone (i.e. the femur) and the shin bone (tibia) (figure 1). Between the bone ends are 2 round discs made of cartilage called the medial (inner) and lateral (outer) meniscus (figure 1). Articular cartilage also lines the respective joint surfaces. The articular cartilage and menisci act as shock absorbers, providing cushioning for the femur as it places pressure on the tibia during weight-bearing activity (e.g. standing, walking, running etc.). The knee cap (patella), situated at the front of the knee, also forms a joint with the femur (i.e. the patello-femoral joint). Strong ligaments and connective tissue (such as the joint capsule) hold the knee bones in alignment, giving the joint stability.

Relevant Anatomy for a Knee Replacement

Figure 1 – Relevant Anatomy for a Knee Replacement

Anatomical structures within the knee (including the menisci, articular cartilage or bony surfaces) may be injured due to trauma, repetitive or prolonged strain or specific conditions (such as avascular necrosis, tumours or rheumatoid arthritis). This may cause gradual, irreversible degeneration to the knee or knee osteoarthritis. When these changes are severe and cause marked pain and functional limitation, knee replacement surgery may be indicated. This may be particularly suitable for patients with severe knee osteoarthritis who have not improved sufficiently with an appropriate physiotherapy rehabilitation program and treatment.

Knee replacement surgery usually takes around 2 – 4 hours to complete and is typically performed under a general anaesthetic, or occasionally, spinal anaesthetic. Antibiotic, or other medications, are typically administered before surgery to prevent infection or other possible complications.

Surgery usually entails an incision of around 30cm down the front of the knee / knee cap. Muscle and other soft tissue are moved to provide access to the knee joint. This is followed by cutting and then removing the diseased surfaces of the tibia and femur. The artificial prosthesis is then positioned and fixated with the use of bone cement. The knee cap is removed if required and replaced with a prosthetic ‘button’. Ligaments and muscles are rearranged and a drainage tube is placed into the wound. The wound is closed with clips or stitches. Knee replacement surgery typically involves a 7 – 10 day hospital stay. Patients who experience complications (such as infection) may require a longer period.


Indications for a knee replacement

Knee replacement surgery may be appropriate in patients with specific knee conditions (such as severe arthritis). It may be particularly indicated in those patients with severe pain and functional limitation (due to their condition) who have not responded adequately to conservative measures (entailing appropriate physiotherapy treatment and a high quality rehabilitation program).

An orthopaedic surgeon can determine whether a knee replacement is indicated based on several factors including:

  • Injury severity and diagnosis
  • Severity of symptoms (such as pain and movement restriction)
  • Level of functional disability experienced by the patient
  • Expected functional and symptomatic improvement following surgery
  • Ability to comply with rehabilitation
  • Age, occupation and recreational activities of the patient
  • Cost
  • Patient health and past medical history
  • Potential surgical complications

Some knee conditions that are often treated with knee replacement surgery may include:

  • Severe knee osteoarthritis or rheumatoid arthritis
  • Avascular necrosis (i.e. bone death due to loss of blood supply)
  • Gout
  • Infection or ligament damage leading to severe osteoarthritis
  • Bone dysplasias (i.e. abnormal bony growth)
  • Certain tumours

Signs and symptoms following a knee replacement

Following knee replacement surgery, symptoms may vary markedly between patients depending on a variety of factors. These factors may include:

  • pre-operative injury severity
  • flexibility and strength of the knee prior to surgery
  • severity of tissue trauma during surgery
  • age of the patient
  • pain perception, attitudes, beliefs and prior experiences
  • psychological well-being of the patient
  • quality of rehabilitation following the procedure
  • type of anti-inflammatory or pain relief medication used

In some cases, patients may only experience minimal symptoms (such as stiffness and minor soreness) following a knee replacement. Although this occurs in a minority of patients it is more likely in:

  • younger patients
  • patients who have excellent strength and flexibility of the knee prior to surgery
  • those patients using appropriate medication
  • patients who adhere to appropriate rehabilitation under physiotherapy guidance
  • those patients with a positive, low stress state of mind and excellent support network

Typical symptoms

Most patients experience prominent pain, swelling, and knee stiffness with symptom intensity ranging from minimal to severe. Pain may be situated in the back, front or sides of the knee and may radiate into the thigh, calf, shin, ankle or foot. Tenderness on firmly touching the knee (particularly on the surgical scars) is also usually experienced. Patients often experience an increase in symptoms during:

  • repetitive or prolonged weight bearing activity (e.g. excessive walking or standing especially up or down hills or on hard or uneven surfaces)
  • excessive bending, straightening or twisting of the knee
  • climbing up or down stairs
  • attempting to kneel
  • repetitive, prolonged or forceful squatting, lifting or carrying.

Patients may also walk with a noticeable limp, or, in rare cases, be unable to weight bear due to pain. Symptoms may also be more prominent with prolonged periods of rest and may present as an ache, pain or stiffness that increases at night or upon waking in the morning.

In some cases, the knee may also feel unstable or weak and occasionally may give way or feel like it’s going to give way during certain activities. Bruising (particularly in the first few weeks), an occasional clicking sensation in addition to pins and needles or numbness are also common symptoms. These symptoms fluctuate in intensity between patients.


Treatment following a knee replacement

Directly following knee replacement surgery the knee is usually covered with a dressing and a drainage tube is used to remove excess fluid from the joint. Antibiotics and blood thinning medication are usually given to reduce the risk of infection and blood clot formation (DVT). Strong pain relief is administered often via an epidural or drip. Early exercises to move the feet and other leg, as well as deep breathing exercises are encouraged as soon as possible, along with the use of compressive TED stockings, to reduce the risk of clot formation and other complications.

Patients are usually encouraged to sit out of bed on the first day after surgery (with assistance from the physiotherapist) and to walk around on the second day after surgery with the assistance of crutches or a walking frame, and, under physiotherapy guidance. The treating physiotherapist will advise how to perform appropriate knee exercises. The use of a continuous passive motion machine may also be advised by some surgeons. Stitches may be dissolvable or are usually removed approximately 10 days after surgery.

Knee replacement treatment once home from hospital

Following knee replacement surgery and discharge from hospital, most patients heal well with appropriate physiotherapy. The success rate of treatment is largely dictated by patient compliance. Crutches or a walking frame are usually required for days to weeks as guided by the surgeon and treating physiotherapist. Activities which place large amounts of stress through the knee should be avoided particularly excessive twisting and weight bearing activities (such as prolonged standing or walking, lifting, squatting, jumping, hopping, kneeling and running etc.).

Regular rest periods (e.g. sitting or lying) are often indicated at frequencies and durations to prevent symptom exacerbation during repetitive or prolonged activity such as walking or standing. Rest from aggravating activities allows the healing process to take place in the absence of further damage. Once the patient can perform these activities pain free, a gradual return to these activities and weight bearing forces is indicated provided there is no increase in symptoms. This should take place over a period of weeks to months with direction from the treating physiotherapist.

Following a knee replacement, patients usually benefit from following the R.I.C.E. Regime. The R.I.C.E regime is beneficial in the first 72 hours following surgery or when inflammatory signs are present (i.e. morning pain, night pain, pain with rest, or new swelling). This involves resting from aggravating activities (the use of crutches, a walking frame or a walking stick may be required), regular icing (i.e. 20 minutes every 2 hours using an ice pack wrapped in a damp tea towel), the use of a compression bandage and keeping the leg elevated. Anti-inflammatory medication may also significantly hasten the healing process by reducing the pain and swelling associated with inflammation. You should discuss the suitability of medication with your doctor or pharmacist prior to use.

Patients who have undergone a knee replacement should perform regular flexibility and strengthening exercises as part of their rehabilitation to ensure an optimal outcome. Emphasis is placed on restoring ideal knee extension and flexion range of movement and quadriceps strength. Hamstring, gluteal and calf strengthening exercises and balance retraining are also important to improve the strength, function and control of the knee joint with weight-bearing activities. Hydrotherapy exercises or stationary bike are also often indicated to improve movement and strengthen the knee in a low weight bearing environment. The treating physiotherapist can advise which exercises are most appropriate for the patient and when they can should be commenced.

Manual “Hands-on” Therapy from the treating physiotherapist such as massage, joint mobilization, dry needling and electrotherapy are important to improve scar tissue flexibility and range of movement. This is particularly important in the first 6 – 12 weeks following surgery.

Review with an occupational therapist may be indicated to teach strategies to improve function and mobility around the home or workplace. This may include the use of appropriate aids, high chairs, rails etc.

In the final stages of rehabilitation, a gradual return to activity can occur as guided by the treating physiotherapist provided there is no increase in symptoms.


Prognosis following a knee replacement

Approximately 90% of patients who have a knee replacement experience improved mobility and less pain compared to before surgery. The recovery period varies significantly from patient to patient depending on a range of factors. Rehabilitation usually lasts 3 – 12 months or longer. It is important to be aware that a prosthetic knee replacement does not function the same as a normal knee (primarily due to reduced knee bending range of motion).

Some patients may require an extended period of rehabilitation following surgery. This may be the case in patients with more extensive knee injuries, with severe knee weakness or stiffness prior to surgery. Extended rehabilitation may also be required for patients who experience complications of surgery such as infection, or damage to local nerves or blood vessels. During rehabilitation, patients who do not rest sufficiently from aggravating activities (such as walking or standing excessively) or those who do not perform regular, appropriate rehabilitation exercises may also slow their recovery and adversely affect their outcome.

A knee prosthesis typically lasts 20 years or longer although excessive stress and strain (e.g. associated with obesity or excessive activity) may reduce its life span. Maintenance of a healthy body weight is therefore important to enhance the longevity of a knee replacement.


Physiotherapy following a knee replacement

Physiotherapy treatment is essential to hasten recovery and optimise the outcome in all patients following knee replacement surgery. Ideally, treatment should commence before surgery and may comprise:

  • Education
  • Activity modification advice
  • The use of crutches, a walking stick or walking frame
  • Anti-inflammatory advice
  • Progressive rehabilitation exercises to improve flexibility, strength (especially the quadriceps muscle), balance and control
  • Hydrotherapy
  • Soft tissue massage
  • Joint mobilization
  • Dry needling
  • The use of a compression support
  • Electrotherapy
  • Ice or heat treatment
  • Biomechanical correction (e.g. the use of orthotics)
  • Weight loss advice where indicated
  • A gradual return to activity program

Potential complications following a knee replacement

Although mostly uncommon, some of the possible complications of knee replacement surgery may include:

  • Temporary or permanent numbness around the incision
  • Wound infection
  • Lung infection
  • Deep vein thrombosis
  • Allergic reaction to the anaesthetic
  • Joint dislocation
  • Failure of the prosthesis (loosening or breaking)
  • Damage to blood vessels in the leg
  • Amputation of the leg due to severe wound infection or blood vessel damage
  • Paralysis of the foot due to nerve damage
  • Pulmonary emboli
  • Heart Attack
  • Stroke
  • Death

Please note that most of these complications are extremely uncommon and very rarely encountered in Physiotherapy clinical practise. One exception being temporary or permanent numbness around the incision which typically affects the majority of patients.


Other intervention following a knee replacement

Despite appropriate treatment and physiotherapy management, some patients do not improve sufficiently following surgery. In these cases, the treating surgeon, doctor or physiotherapist can advise on the best management plan. This may comprise pharmaceutical intervention, further investigations (such as X-rays), manipulation under anaesthetic (to improve knee joint range of motion) or in rare cases, additional surgery.


Exercises following a knee replacement

The following rehabilitation exercises are often prescribed to patients following knee replacement surgery. These can typically commence once the physiotherapist or orthopaedic surgeon have advised it is safe to do so. You should discuss the suitability of these exercises with your physiotherapist prior to commencement. Generally, they should be performed 3 – 4 times each day and only provided they do not cause or increase symptoms.

Your physiotherapist can advise when it is appropriate to begin the initial exercises and eventually progress to the intermediate, advanced and other exercises. As a general rule, addition of exercises should take place provided there is no increase in symptoms.


Initial Exercises

Knee Bend to Straighten

Bend and straighten your knee as far as possible and comfortable without increasing your pain (figure 2). Aim for no more than a mild to moderate stretch in each direction. Repeat 10 – 20 times provided there is no increase in symptoms.

Exercises Following a Knee Replacement - Knee Bend to Straighten

Figure 2 – Knee Bend to Straighten (right leg)

Static Quadriceps Contraction

Tighten the muscle at the front of your thigh (quadriceps) by pushing your knee down into a small towel (figure 3). Put your fingers on your inner quadriceps to feel the muscle tighten during contraction. Hold for 5 seconds and repeat 10 times as hard as possible and comfortable without increasing your symptoms.

Exercises Following a Knee Replacement - Static Quadriceps Contraction

Figure 3 – Static quadriceps contraction (left leg)

Quads over Fulcrum

Begin this exercise lying on your back with a foam roller or rolled towel under your knee and your knee relaxed. Slowly straighten your knee as far as possible tightening the front of your thigh (quadriceps) (figure 4). Hold for 5 seconds and repeat 10 times as hard as possible provided there is no increase in symptoms.

Exercises Following a Knee Replacement - Quads over Fulcrum

Figure 4 – Quads over fulcrum (left leg)

Knee Bend in Sitting

Begin this exercise sitting with your back and neck straight in an appropriate chair (allowing you to bend your knee beneath it). Bend your knee as far as you can go without pain and provided you feel no more than a mild to moderate stretch (figure 5). Repeat 10 – 20 times holding each stretch for 1 – 5 seconds provided there is no increase in symptoms. Once this is easy, you can progress the stretch by using your other leg to gently assist the movement. Simply cross your legs at the level of your ankle and use the heel of your other leg to push the shin of your leg being stretched a little further. Ensure this progression does not cause or increase symptoms.

Exercises following a Knee Replacement - Knee Flexion in Sitting

Figure 5 – Knee Bend in Sitting

Heel Raises

Begin this exercise standing at a bench or chair for balance (figure 6). Keep your feet shoulder width apart and facing forwards. Slowly move up onto your toes, raising your heels as far as possible and comfortable without pain. Perform 10 – 20 repetitions provided the exercise is pain free.

Exercises following a Knee Replacement - Heel Raises

Figure 6 – Heel Raises

Hip Extension in Standing

Begin this exercise standing on your good leg at a bench or chair for balance as demonstrated (figure 7). Keeping your back and knee straight, slowly take your other leg backwards tightening your buttock muscles (gluteals). Then slowly return the leg back to the starting position. Perform 10 – 20 repetitions as far as possible provided the exercise is pain free. Once you can comfortably perform this exercise without pain standing on your operated leg, this exercise should be performed on both sides.

Exercises following a Knee Replacement - Hip Extension in Standing

Figure 7 – Hip Extension in Standing (right leg)

Hip Abduction in Standing

Begin this exercise standing on your good leg at a bench or chair for balance as demonstrated (figure 8). Keeping your back and knee straight, slowly take your other leg to the side tightening the muscles at the side of your hip (gluteals). Then slowly return the leg back to the starting position. Perform 10 – 20 repetitions as far as possible provided the exercise is pain free. Once you can comfortably perform this exercise without pain standing on your operated leg, this exercise should be performed on both sides.

Exercises following a Knee Replacement - Hip Abduction in Standing

Figure 8 – Hip Abduction in Standing (right leg)


Intermediate Exercises

Knee Extension with Overpressure

Begin this exercise in the position demonstrated with your foot on a chair or coffee table (figure 9). Initially this exercise should be performed without the use of your hands / arms. Gently push your knee straight (tightening your quadriceps muscle) until you feel a mild to moderate stretch (ensure you only use your leg to begin with). Hold for 1 – 5 seconds and repeat 10 times provided the exercise is pain free. Once this is easy and causing no discomfort, the exercise can be progressed by using your arms to gently apply a little extra pressure provided there is no increase in symptoms (figure 9).

Exercises following a Knee Replacement - Knee Extension with Overpressure

Figure 9 – Knee Extension with Overpressure (right leg)

Knee Flexion with Towel

Begin this exercise lying on your back. Bend your knee as far as possible and comfortable without increasing symptoms. Then use a towel (placed over your shin) and your hands to gently pull it a little further (figure 10). Move as far as you can go without pain and provided you feel no more than a mild to moderate stretch. Hold for 1 – 5 seconds and repeat 10 times provided the exercise is pain free.

Exercises following a Knee Replacement - Knee Flexion with Towel Overpressure

Figure 10 – Knee Flexion with Towel (right leg)

Static VMO in Sitting

Begin this exercise with your back and neck straight and your knees in line with your middle toes. Tighten the muscle at the front of your thigh (quadriceps) by pushing your foot down into the ground (as though you’re trying to squash a spider under your mid foot) (figure 11). Put your fingers on your inner quadriceps to feel the muscle tighten during contraction. Hold for 5 seconds and repeat 10 times as hard as possible and comfortable without increasing your symptoms.

Static Quads (VMO) in Sitting CKC

Figure 11 – Static VMO in sitting

Hamstring Stretch

Place your foot on a step or chair and hold onto something for balance (e.g. a bench). Keeping your knee and back straight, lean forward at your hips as far as you can go without pain and provided you feel no more than a mild to moderate stretch (figure 12). Hold for 15 seconds and repeat 4 times provided the exercise is pain free. Repeat the exercise on each leg.

Exercises following a Total Knee Replacement - Hamstring Stretch

Figure 12 – Hamstring Stretch (left leg)

Calf Stretch

With your hands against the wall, place your leg to be stretched behind you as demonstrated (figure 13). Keep your heel down, knee straight and feet pointing forwards. Gently lunge forwards as far as you can go without pain and provided you feel no more than a mild to moderate stretch in the back of your calf / knee. Hold for 15 seconds and repeat 4 times at a mild to moderate stretch provided the exercise is pain free. Perform this exercise on each leg.

Exercises following a Total Knee Replacement - Calf Stretch

Figure 13 – Calf Stretch (left leg)

¼ Squat with Resistance Band

Begin this exercise in standing with your feet shoulder width apart, your feet facing forwards, your hands holding a stable bar (or bench) and a resistance band tied around your knee as demonstrated (figure 14). Slowly perform a quarter squat by sticking your bottom out and keeping your back straight. Your knees should be in line with your middle toes and should not move forward past your toes. Perform 5 – 15 repetitions provided the exercise is pain free. This exercise can also be performed with less resistance (and less quadriceps activation) without a resistance band

1/4 squat with resistance band

Figure 14 – ¼ Squat with Resistance Band

Bridging

Begin this exercise lying on your back in the position demonstrated (figure 15). Slowly lift your bottom pushing through your feet, until your knees, hips and shoulders are in a straight line. Tighten your bottom muscles (gluteals) as you do this. Hold for 2 seconds then slowly lower your bottom back down. Repeat 10 – 20 times provided the exercise is pain free.

Exercises following a Total Knee Replacement - Bridging

Figure 15 – Bridging

Calf Raises Over Step

Begin this exercise standing with your heels dropped below the level of a step as demonstrated (figure 16). Ensure you have something to hold onto for balance. Slowly move up onto your toes, raising your heels as far as possible and comfortable without pain, tightening your calf muscles. Then slowly lower back down. Perform 10 – 30 repetitions provided the exercise is pain free.

Exercises following a Total Knee Replacement - Heel Raises over Step

Figure 16 – Calf Raises Over Step

Squat with Swiss Ball

Begin this exercise in standing with your feet shoulder width apart, your feet facing forwards and a Swiss ball placed between a wall and your lower back (figure 17). Slowly perform a squat, keeping your back straight. Your knees should be in line with your middle toes and should not move forward past your toes. Begin with a shallow quarter squat and repeat 5 – 20 times provided there is no increase in symptoms. Gradually increase the squat depth over a number of days to weeks so that eventually you are performing a squat to a 90 degree knee bend, provided there is no increase in symptoms.

Squats with Swiss Ball

Figure 17 – Squat with Swiss Ball


Advanced Exercises

Knee Bend in Sitting

Begin this exercise sitting with a straight back and neck in an appropriate chair (allowing you to bend your knee beneath it). Bend your knee as far as you can go without pain and provided you feel no more than a mild to moderate stretch (figure 18). Repeat 10 – 20 times holding each stretch for 1 – 5 seconds provided there is no increase in symptoms. Once this is easy, you can progress the stretch by using your other leg to gently assist the movement. Simply cross your legs at the level of your ankle and use the heel of your other leg to push the shin of your leg being stretched a little further. Ensure this progression does not cause or increase symptoms.

Knee Flexion in Sitting

Figure 18 – Knee Bend in Sitting

Hip Abduction in Standing

Begin this exercise standing on your good leg at a bench or chair for balance as demonstrated (figure 19). Keeping your back and knee straight, slowly take your other leg to the side tightening the muscles at the side of your hip (gluteals). Then slowly return the leg back to the starting position. Perform 10 – 20 repetitions as far as possible provided the exercise is pain free. Once you can comfortably perform this exercise without pain standing on your operated leg, this exercise should be performed on both sides.

Hip Abduction (Standing)

Figure 19 – Hip Abduction in Standing (right leg)

Step Ups

Begin this exercise standing in front of a small step with your feet shoulder width apart, your feet facing forwards (figure 20) and holding a rail for stability. Keeping your back straight, slowly perform a step up leading with your operated leg. Your knees should be in line with your middle toes. Place your fingers on your inner quadriceps (VMO) to feel them contract during the exercise. Then step back down leading with your operated leg. Repeat 5 – 20 times provided there is no increase in symptoms. Once this is too easy, you can progress the exercise by stepping down with your uninjured side first and by increasing the size of the step provided there is no increase in symptoms. 

Step Ups (VMO focus)

Figure 20 – Step Ups (right leg)

Single Leg Bridging

Begin this exercise lying on your back in the position demonstrated (figure 21). Slowly lift your bottom pushing through your foot, until your knee, hip and shoulder are in a straight line. Tighten your bottom muscles (gluteals) as you do this and hold for 2 seconds. Then slowly lower back down. Perform 10 – 20 repetitions on each leg provided the exercise is pain free.

Single Leg Bridging

Figure 21 – Single Leg Bridging (left leg)

Single Leg Calf Raise Over Step

Begin this calf strengthening exercise standing on one leg with your heel dropped below the level of a step (figure 22). Ensure you have something to hold onto for balance. Slowly move up onto your toes, raising your heel as far as possible and comfortable without pain, tightening your calf. Then slowly lower back down. Perform 5 – 30 repetitions provided the exercise is pain free. Once this is too easy, the exercise can be progressed by holding a weight provided there is no increase in symptoms.

Calf Raises (Single Leg on Step)

Figure 22 – Single Leg Calf Raise Over Step (left leg)

Single Leg Balance

Ensure you begin this exercise in a safe environment (e.g. at a bench or with a spotter) to prevent falls. Standing on one leg, maintain your balance (figure 23). Try to hold for 1 minute. Once this exercise is too easy progress to eyes closed.

Single Leg Balance

Figure 23 – Single Leg Balance (right side)

Lunges

Begin this exercise standing with your back straight in the position demonstrated (figure 24). Begin by holding onto a bench for balance. Slowly lower your body a little keeping your knee in line with your middle toe and your feet facing forward. Perform 5 – 20 repetitions on each leg provided the exercise is pain free. Once this is too easy, progress the exercise by lunging a little deeper until you are eventually bending the front knee to a 90 degree angle provided there is no increase in symptoms.

Static Lunges

Figure 24 – Lunges


Other Exercises

Stationary Exercise Bike

Begin sitting with a straight back and neck and your bottom back on an appropriate stationary exercise bike (figure 25). Ensure the seat is setup so it is reasonably far away from the pedals and your affected knee is almost straight at the bottom of the pedalling motion. Keeping your feet on the pedals, slowly and gently bend your affected knee as far as you can go without pain and provided you feel no more than a mild to moderate stretch. Then move your feet in the opposite direction moving through only a partial revolution. Repeat 10 – 20 times provided there is no increase in symptoms. Gradually build up the size of the movements over time until you can eventually move your feet through a continuous pedaling motion, then build up the resistance and your cycling duration over time until you can eventually cycle for 5 – 30 minutes at a moderate to firm resistance. Repeat once every 1 – 4 days provided there is no increase in symptoms.

Exercises Following a Knee Replacement - Cycling on a Stationary Exercise Bike

Figure 25 – Cycling on a Stationary Exercise Bike


Rehabilitation Protocol following a knee replacement

The following is a general rehabilitation protocol for patients following a knee replacement. This needs to be tailored to each individual and should be discussed with your orthopaedic surgeon and treating physiotherapist prior to commencing. Progression through this program can vary from weeks to months depending on numerous factors such as your age, your pre-operative strength and flexibility, your compliance, any complications and the quality of treatment:

  • See your physiotherapist and doctor as soon as possible to establish the likely prognosis, identify the contributing factors to your injury and surgery, and begin appropriate treatment.
  • Follow the R.I.C.E. Regime when inflammatory signs are present (new swelling, night-time pain, morning ache / stiffness or pain at rest). This should primarily comprise:
    • Rest from any activity that increases pain, particularly excessive weight bearing activity, kneeling, squatting, lunging, lifting, or twisting activities (the use of crutches, a walking stick or other gait aid, or knee taping may be required)
    • Ice the sore area for 20 minutes and repeat every 2 hours (using an ice pack wrapped in a damp tea towel)
    • Compress the knee with an appropriate compression bandage. This should be removed at night or if it is too tight (i.e. there should be no colour change, pins and needles, numbness or discomfort in the lower leg, foot or toes).
    • Elevate the affected leg above the level of your heart whenever possible
    • Anti-inflammatory and / or pain relieving medication are often beneficial for a period of time (these should be discussed with your doctor and/or pharmacist prior to use).
  • Avoid H.A.R.M. when inflammatory signs are present (new swelling, night-time pain, morning ache / stiffness or pain at rest) including:
    • Heat (avoid using heat on the injured area, this includes the use of heat packs, hot baths, showers or spas)
    • Alcohol consumption
    • Rigorous Exercise of the affected body part
    • Massage
  • “Initial Exercises” can usually commence once your orthopaedic surgeon or physiotherapist have indicated it is safe to do so provided they are comfortable and do not increase symptoms. Generally you should begin with one or two of the ‘Initial Exercises’ and gradually add the remaining ‘Initial Exercises’ over a number of days provided there is no increase in symptoms.
  • Settle symptoms – Aim to settle symptoms as quickly as possible by avoiding aggravating activities. Any activity that increases pain during the activity or after the activity with rest (i.e. the next night or upon waking the following morning) should be avoided or reduced to prevent any increase in symptoms. These activities may include:
    • excessive weight bearing activities, such as excessive standing or walking (particularly on hard or uneven surfaces or up or down stairs or hills or without appropriate gait aids)
    • lifting heavy objects or carrying items over long distances (e.g. carrying shopping)
    • twisting or change of direction activities (e.g. moving back and forth in the kitchen whilst preparing a meal)
    • kneeling, lunging or squatting
    • prolonged driving (especially operating the pedals)
    • running, jumping and landing activities.
  • The use of crutches, a walking stick or other gait aid or sometimes knee taping is usually indicated if walking is painful or causing a limp. The device you use will depend on your situation, but must be sufficient to ensure walking is pain free and limp free. Crutches are generally the most appropriate provided they can be safely used. If using crutches, a walking stick or other gait aid, walk normally, but take enough weight off the injured leg so walking is pain free and limp free. Sometimes smaller steps may be required for a period of time. Once symptoms settle, gradually increase weight through the injured side as tolerated provided there is no increase in pain, limp or unsteadiness until eventually you can walk with only one stick or crutch and then ideally no gait aid (see how to use crutches).
  • When symptoms are severe, decrease the time you spend weight bearing and increase rest period duration and frequency. Ensure you choose rest positions that are comfortable for you (lying or sitting in positions of comfort with or without pillows to support the knee are usually most appropriate).
  • When symptoms improve, increase your activity levels gradually whilst being careful not to increase your symptoms. When symptoms settle, aim for pain free rehabilitation. Gradually increase activity levels and progress exercises to improve strength, flexibility, balance and function, provided there is no increase in symptoms during activity or upon rest following activity (e.g. that night or upon waking the next morning). This should take place over weeks to months depending on your circumstances and under close guidance from the treating physiotherapist.
  • If using tape, gradually reduce the duration of use as symptoms improve and provided there is no deterioration of symptoms. The use of tape during at risk activities (such prolonged weight bearing activity or sport) may still be indicated.
  • Do not increase activity levels too rapidly especially in the first 6 weeks beginning from when symptoms have settled. During this period, injury recurrences are common. Be particularly careful when returning to weight-bearing activity, lifting, carrying, high impact activities, twisting, squatting, lunging, walking and standing. Ensure you regulate the duration, frequency and intensity of all activity to prevent symptom recurrence.
  • Heat treatment can usually occur provided there is no inflammation (i.e. night-time pain, morning pain or pain at rest). Apply a heat pack to the injured area at a comfortable warmth for 20 – 30 minutes before exercises or as frequently as desired. If there are still signs of inflammation continue to use ice instead of heat.
  • Gradually progress to the “Intermediate Exercises” once the “Initial Exercises” can be performed pain free for a few days consecutively. Ensure all new exercises do not increase symptoms. The ‘Intermediate Exercises’ should be added to the ‘Initial Exercises’. Generally you should begin with one or two ‘Intermediate Exercises’ and gradually add the remaining ‘Intermediate Exercises’ over a number of days to weeks provided there is no increase in symptoms.
  • The “Other Exercises” can be added to the ‘Intermediate Exercises’ provided there is no increase in symptoms. Your treating physiotherapist can advise which exercises are most appropriate for you and when they can commence.
  • Some patients may find specific exercises (or performing too many exercises) provocative for their knee and may subsequently have to modify their program appropriately. In these situations, it is generally advisable to avoid aggravating exercises or choose only a selection of the most helpful exercises that the knee can tolerate without aggravating symptoms. This should be discussed with the treating physiotherapist.
  • Increase walking distance, and eventually speed, gradually, and, provided there is no increase in pain or limp (this should take place over days to weeks). Moderate the duration, frequency and intensity of your walking to ensure there is no increase in symptoms during or after walking with rest (e.g. the next night or upon waking the following morning).
  • Maintain cardiovascular fitness with gentle forms of cardiovascular exercise that do not increase symptoms. Cycling, walking, hydrotherapy, swimming (freestyle or backstroke) or the use of a cross trainer may be appropriate. These may be changed to other forms of training, if desired, or progressed by gradually increasing the duration, frequency or intensity of training provided there is no increase in symptoms during the activity or after the activity with rest (e.g. the following morning). This should take place over weeks to months with direction from the treating physiotherapist. Aim to eventually build up your total cardiovascular exercise to 150 minutes or more of moderate intensity exercise per week provided there is no increase in symptoms.
  • Eventually progress to the “Advanced Exercises” once the “Intermediate Exercises” can be performed pain free for a few days consecutively. Ensure all new exercises do not increase symptoms. The ‘Advanced Exercises’ should replace the ‘Initial Exercises’ and be added to the ‘Intermediate’ and ‘Other Exercises’. Generally you should begin with one or two ‘Advanced Exercises’ and gradually add the remaining ‘Advanced Exercises’ over a number of days to weeks provided there is no increase in symptoms.
  • Further Leg Strengthening exercisesLeg Stretches, Gym Exercises and Balance Exercises may be added to improve strength, flexibility and control of the knee and lower limb. These should be implemented gradually and provided there is no increase in symptoms. Your treating physiotherapist can advise which exercises are most appropriate for you and when they can commence.
  • Ensure your physiotherapist has identified the contributing factors to your injury and appropriate intervention has taken place to address these issues to minimise the likelihood of future problems.
  • Assessment with a podiatrist may be required for possible orthotics or footwear advice, particularly in patients with flat feet or high arches (see Do I Need Orthotics).
  • A gradual return to activity and low impact sports (such as golf, lawn bowls, croquet etc.) can occur provided there is no increase in symptoms and under guidance from your treating physiotherapist.
  • Maintain healthy lifestyle habits to optimise healing – such as performing regular exercise (without increasing symptoms), eating a well-balanced diet with a variety of fresh fruits, vegetables and whole foods and low in processed foods, saturated fats, salt and sugar. Maintaining adequate hydration with water as your primary source of fluid. Minimise alcohol consumption and avoid smoking. Maintain a healthy body weight and a healthy, positive, low stress state of mind (see ‘Strategies to reduce pain and suffering’ in our article ‘Understanding Pain’). Ensure you are getting adequate sleep and maintain a great social support network.

Physiotherapy Products following a Knee ReplacementPhysiotherapy products for a knee replacement

Some of the most frequently recommended products by physiotherapists to accelerate healing and optimise recovery in patients following a knee replacement include:

    1. Crutches, 4 Wheel Walkers or Walking Sticks
    2. Ice Packs or Hot Packs
    3. Compression Bandages
    4. Foam Rollers (for self massage)
    5. Spikey Massage Balls (for self massage)
    6. Resistance Band (for strengthening exercises)
    7. Swiss Balls (for strengthening exercises)
    8. Protective Tape
    9. Orthotics

To purchase a physiotherapy product following a knee replacement click on the relevant link above or visit the PhysioAdvisor Shop.


More Exercises following a Knee Replacement More exercises following a knee replacement


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