This blog is for individuals considering a knee replacement, already scheduled for a procedure, or those who have started the post-operative rehabilitation process. If you haven’t done so already, check out our blog on knee osteoarthritis discussing non-surgical management strategies.
Be sure to also check out our Knee Resilience Program!
What Is A Total Knee Replacement?
Total Knee Replacement (TKR), or Total Knee Arthroplasty (TKA), refers to the removal and replacement of damaged portions of bone and cartilage at the ends of the tibia (shin bone), femur (thigh bone), and patella (knee cap). These new implants are typically composed of metal and synthetic materials. Another synthetic material, commonly plastic based, is cemented on top of the tibial (shin) implant to reduce friction with the femoral implant. Individuals experiencing symptomatic osteoarthritis suffering from persistent pain, loss of function, strength, and limited mobility (with an unsuccessful bout of non-operative management) are the primary candidates for receiving a TKA.
In the upcoming sections, I am going to answer frequently asked questions following a TKA.
How Long Will I Be In The Hospital?
3 days is the average hospital length of stay following a TKA procedure (Papalia et al in 2022). Fast-track TKA procedures, aimed at expediting early mobilization (ambulating the day of surgery) and recovery (Capagner et al in, 2023), demonstrate even shorter hospital stays, averaging 1-2 days, without an increase in readmission or mortality rates (Peterson et al in, 2020). A host of factors may increase the hospital length of stay including: presence of comorbidities such as arterial hypertension and diabetes mellitus, longer surgical time, and intraoperative blood loss (Papalia et al in 2022).
When Can I Start Walking On My Surgical Limb?
Patients are typically up and walking in the hospital within 24-48 hours after their procedure. Walking within the first 24 hours is associated with a decreased hospital length of stay and reduces the risks associated with prolonged bed rest (Guerra et al in 2015) (Henderson et al in 2017). You will be assisted by the nursing and rehabilitation staff during these bouts of walking, and you will have some form of assistive device, most commonly a walker (Guerra et al in 2015) (Henderson et al in 2017).
How Do I Monitor For A Deep Vein Thrombosis?
A Deep Vein Thrombosis (DVT) is a blood clot that can commonly form after a surgery, particularly in the calf region of your lower leg. There are a collection of signs and symptoms that indicate a potential DVT. These include, but are not limited to, excessive swelling along the entire leg or lower leg / calf region, warmth, localized tenderness around the calf, and pitting edema (Stone et al in 2017).
If there are any concerns regarding a potential DVT, it is recommended to immediately go to the emergency department for further testing and management. Other complications that should be monitored include: bleeding, failure of wound healing, loss of sensation or motor function, vascular injury, instability of the knee joint, and infection. Your orthopedic / surgical team should be informed of any new or worsening symptoms.
Do I Need To Ice My Knee?
A recent Cochrane systematic review by Aggarwal et al in 2023 suggests that icing within 48 hours following TKA has low levels of evidence for its impact on blood loss, pain, and range of motion, and very low levels of evidence for improving transfusion rate, function, and total adverse events. The authors go on to state that, “the potential benefits of cryotherapy on blood loss, pain and range of motion may be too small to justify its use.” If applying ice to your knee improves your tolerance to working on range of motion and performing rehabilitation exercises during the first few days or weeks, go for it. If you don’t find it beneficial, the current evidence suggests it’s probably not hindering your recovery and long-term outcomes.
Should I Purchase Or Use A Continuous Passive Motion Machine?
No. Continuous passive motion machines, or CPMs, do not significantly improve postoperative range of motion, pain, or function. A recent systematic review and meta-analysis by Jia et al in 2024 states that, “the results of this current study are insufficient to support the routine use of CPM to facilitate the recovery process after arthroplasty.” The latest clinical practice guideline covering the management of TKA’s advises against the use of CPM’s due to a variety of factors including inconvenience of use, cost, and time spent in bed (Jette et al in 2020).
When Should I Stop Using My Assistive Devices?
There is no black and white answer here. Factors influencing the time it takes to wean off of all assistive devices (AD) include: prior level of function and whether or not you used an AD prior to surgery, severity of fall risk, confidence levels, and recommendations from your orthopedic and rehabilitation teams. My biggest recommendation is to not rush this process. The AD has an intended benefit / purpose of managing knee discomfort and swelling due to offloading of the surgical limb in addition to a safer / more efficient means of ambulation. Transitioning from a walker, to a single point or quad cane, and finally to no AD is the typical progression.
However, there are instances where it is safe and reasonable for individuals to transition straight from a walker to no AD, pending the recommendation and approval from the orthopedic and rehab teams. On the flip side, it is not uncommon for individuals to maintain the use of an assistive device long-term.
What Should I Expect My Knee Range Of Motion To Be?
The ultimate range of motion of your knee will depend on a host of factors including: your pre-surgical range of motion, body mass levels, consistency and effort with range of motion exercises, and pain levels. Most post-op TKA protocols shoot for at least 0-115 or 0-120 degrees of knee range of motion (Ohio State, Delaware, Brigham and Women’s Hospital). This means that your knee can fully straighten / extend and your knee can bend / flex 120 degrees towards your body.
The knee joint requires certain ranges of motion to accomplish daily activities. For example, walking requires roughly 70 degrees of knee flexion, descending stairs roughly 100 degrees of knee flexion, sitting down to a standard chair height roughly 100 degrees, and getting in and out of a bath roughly 135 degrees (Rowe et al in 2000).
Kittelson et al in 2020 developed a useful reference chart for both patients and providers to track range of motion and compare across days, weeks, and months after the TKA procedure. In this group of 327 patients post TKA, the 50th percentile achieved roughly 115 degrees of knee flexion between 40 and 60 days out from their procedure. The 90th percentile achieved 130 degrees between 40 and 60 days.
How Long Will My Total Knee Replacement Last For?
A substantial majority of TKA’s last between 15-25 years. At 10 and 15 years, Rashed et al in 2021 report a survival rate of 96.7% and 95.4%. The systematic review and meta-analysis performed by Evans et al in 2019 suggest that 82% of TKA’s last for 25 years in patients who previously had osteoarthritis.
Is Resistance Training Safe After A Total Knee Replacement?
Yes, resistance training is both safe and recommended following a TKA (Jette et al in 2020). A significant proportion of your post-operative rehabilitation will consist of lower body resistance-based exercises, through both progressively greater ranges of motion and weight, in order to regain the strength, function, and capacity of your surgical leg.
Further details regarding appropriate starting points and progressions of exercise and resistance training is available at the end of this article.
Can I Return Back To A Sport?
A systematic review and meta-analysis performed by Witjes et al in 2016 found that a significant proportion (over 90%) of people will be able to return back to low-impact sports including swimming, golfing, cycling, and walking. Sports classified as intermediate impact, such as hiking, mountain climbing, and downhill skiing have a roughly 64% rate of return. High impact sports including running, tennis, and ball sports have a 43% return following a TKA. There are countless factors influencing your decision to return back to a certain sport including: interest / desire to return, age, recommendations from your surgeon and other healthcare providers to return to or avoid certain activities / sports, confidence levels, fear of injury or of expediting a knee revision surgery, and objective readiness to return.
Dagneaux et al in 2017 note that “High-intensity sports must be advised against, although evidence of increased injury risks or mechanical complications (early damage, unsealing, periprosthetic fracture) is lacking.” At this point in time, there may not be enough high-quality data to determine whether or not high intensity / high impact sports are safe to return back to (Lester et al in 2022). Ultimately, it’s through a shared decision-making process between yourself, your family members, and the orthopedic and rehabilitation teams to determine what is appropriate and safe for you to eventually return back to.
What Will Rehabilitation Entail?
There are a variety of TKA rehabilitation protocols readily available on the internet, with similar timelines, goals, and interventions. Your orthopedic and rehabilitation providers will also have their own protocols and prescriptions. The goal of this final section is to provide you with an idea of what your rehab might look like in these upcoming weeks and months. I am going to utilize Ohio State’s postoperative TKA protocol as a framework here. All of the activities listed below are examples of what home-based rehab options may look like for you throughout this process. Your surgical and rehabilitation teams will provide further instruction and guidance on the specific progression of your rehab.
Phase 1: 0-6 weeks
The major goals / priorities within the first few days / weeks after your procedure include:
- Protect the healing tissues
- Manage pain and swelling
- Identify / monitor any new or worsening symptoms
- Improve range of motion
- Increase quadriceps (thigh) strength
- Normalize walking quality and speed
- Improve confidence and competence with daily activities.
This may seem like a lot of goals / priorities early on, but there is a lot of overlap here. A single intervention / exercise may provide multiple benefits and accomplish multiple goals.
Regaining your knee extension range of motion as soon as possible is a major first goal. I recommend patient’s prop their heel up into knee extension for at least 45-60 minutes, cumulatively by the end of day.
You can start with 5-10 minute bouts, performed 4-6x throughout the day. As your tolerance to this position improves, you can progress to 25-30 minutes per bout while decreasing the frequency to 2x per day. If you want to explore a variety of knee extension positions, please refer to our prior video on this topic.
Regaining knee flexion range of motion is another major goal. Heel slides with assistance from a strap, towel, or belt is our primary starting point. Unlike the knee extension range of motion, heel slides will have designated sets and reps. Generally, the more frequently and the greater overall volume of sets and reps you perform, the better. Shoot for at least 2-3 sets of 15-20 reps of heel slides, 2-3x per day.
Working on knee flexion range of motion can be boring, uncomfortable, and it can take longer than you wish to regain, but it is extremely important. Utilize the reference chart of knee flexion norms I included earlier in this article in order to track your progress (Kittelson et al in 2020). Your goal is at least 115-120 degrees by 8-12 weeks. If you want to experiment with a variety of other knee flexion positions, please refer to our prior video on this topic.
Introducing the upright stationary bike can be done within the first few days or weeks to also improve your knee motion. Initially, you will start with half revolutions, working your way up to full revolutions. The bike is a great means of improving knee knee range of motion in addition to re-integrating a tolerable mode of cardiovascular exercise. Once this is well tolerated, you can use the upright bike as often as you would like, for bouts of 5-20+ minutes.
Regaining quadriceps strength is a major priority for a variety of reasons including: normalizing your walking quality and speed and increasing your tolerance and capacity for a variety of daily activities and valued life activities. There are a host of exercises to accomplish this goal, and you will receive a variety of them from your orthopedic and rehab teams. Something as simple as squeezing the quad muscle as often as possible throughout the day, can be very beneficial during the first few days / weeks. This will help “wake-up” the quad during a period of time when it naturally wants to protect your knee from further damage by not contracting.
Short arc quads, long-arc quads, leg extensions (both isometrics and isotonics), wall sits, squats to a box, and step-ups are a variety of options that should be integrated and progressed over time.
The quality of walking and speed of your walking will improve as your knee range of motion improves, quadriceps strength increases, knee swelling and pain improves, and specific gait training drills / activities progress.
Here is an example of what one day during week 1 may look like for you at home:
- Heel Prop In Extension: 45-60 minutes, cumulatively by the end of the day (for bouts of 3-10 minutes at a time if this is all you can tolerate).
- Heel Slides: 2-3 sets of 10-15 reps, 2-3x per day
- Ankle Pumps: As often as possible
- Quad Sets: As often as possible
- Walking with Assistive Device: 2-3 bouts of 1-5 minutes (depending on tolerance)
- Partial revolutions on the bike: 2-3 bouts of 5-15 minutes
Here is an example of what one day during week 5 may look like for you at home:
- Heel Prop In Extension: 45-60 minutes, cumulatively by the end of the day.
- Heel Slides: 2-3 sets of 10-15 reps, 2-3x per day
- Squats to Chair: 2-3 sets of 8-10 reps
- Step-Ups: 2-3 sets of 8-10 reps
- Double or Single Leg Heel Raises: 2-3 sets of 10-15 reps
- Double or Single Leg Bridges: 2-3 sets of 10-15 reps
- Leg Extensions: 2-3 sets of 10-15 reps
- Walking with or without assistive device: 2-3 bouts of 5-15+ minutes (depending on tolerance)
- Biking: 20-30+ minutes
Phase 2: 6-12 weeks
The major goals / priorities during the Phase 2 of your rehab (weeks 6-12) includes:
- Full (or near full) restoration of your knee flexion and extension range of motion
- Continued improvement in quadriceps (and entire surgical leg) strength
- Normalized gait quality and speed
- Tolerance to daily activities with little to no limitation
Here is an example of what one day towards the end of phase 2 may look like for you at home:
- Weighted Squats to Chair: 3-4 sets of 8-12 reps
- Split Squats: 3-4 sets of 8-12 reps
- Single Leg Heel Elevated Bridges: 3-4 sets of 8-12 reps
- Single Leg Leg Extensions: 2-3 sets of 10-15 reps
- Deficit Single Leg Heel Raises: 3-4 sets of 8-12 reps
- Walking: 1-2 bouts of 15-30+ minutes (depending on tolerance)
- Stationary Bike: 30+ minutes
Phase 3: 12-24+ weeks
The major goals / priorities during Phase 3 of your rehab (weeks 12-24+) includes:
- Full return to your prior level of function (or beyond)
- Restoration of your quadriceps strength and entire lower leg strength (or beyond)
- Initiate progressive plyometric activities (per clearance of physician)
- Progressively return to sport / recreational activities (per clearance of physician)
If you are not looking to return back to running, higher impact activity, or sport, goals 3 and 4 may not apply to you during this final phase of rehab. However, there is still value in introducing and maintaining some level of speed and power based exercises in addition to your normal resistance training-based activities. Maintaining and improving the ability for your legs to perform activities quickly, and with sufficient force, is an important quality when it comes to reducing your risk of falls (Jimenez-Lupion et al in 2023).
Towards the end of your rehab (4-6+ months), here is an example of what one day at home may look like:
- Speed Focused Squats: 2-3 sets of 4-6 reps
- Speed Focused Step-Up: 2-3 sets of 4-6 reps
- Weighted Squats to Chair: 3-4 sets of 6-8 reps
- Single Leg RDL’s: 3-4 sets of 8-12 reps
- Lateral Band Walks: 3-4 sets of 8-12 reps
- Weighted Split Squats: 3-4 sets of 8-12 reps
- Deficit Weighted Single Leg Heel Raises: 3-4 sets of 8-12 reps
- Aerobic Activity of Choice (30-60+ minutes): Biking, incline treadmill walking, brisk outdoor walking, water aerobics, etc.
If you are looking to return back to higher demand activities such as tennis, pickleball, or running, here is an example of what one day at home may look like for you:
- Double Leg Pogos: 3-4 sets of 30 seconds on / 30 seconds off
- Box Jumps: 3-4 sets of 5 reps
- Split Stance Snap Downs: 3-4 sets of 5 reps each side
- Weighted Squats to Chair: 3-4 sets of 6-8 reps
- Single Leg RDL’s: 3-4 sets of 8-12 reps
- Lateral Band Walks: 3-4 sets of 8-12 reps
- Weighted Split Squats: 3-4 sets of 8-12 reps
- Deficit Weighted Single Leg Heel Raises: 3-4 sets of 8-12 reps
- Aerobic Activity of Choice (30-60+ minutes): Biking, incline treadmill walking, brisk outdoor walking, water aerobics, etc.
- In addition, gradual return back to your desired activity of choice. Slowly increase the intensity, duration, and frequency of participation over multiple weeks and months.
Want to learn more? Check out some of our other similar blogs:
Knee Osteoarthritis, Improving Knee Flexion Range of Motion, Improving Knee Extension Range of Motion
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