Total knee replacements -- or total knee arthroplasties (TKA) have become one of the most performed orthopedic surgeries in the world. According to the Agency for Healthcare Research and Quality, in 2017, more than 754,000 knee replacements were performed in the United States. In the PT clinic I treat as many patients after total knee replacements as any other orthopedic surgery. In orthopedic healthcare, total knee replacements are widely regarded as one of the most successful surgeries. The AAOS notes that over 90 percent of replacement knees are still functioning after 15 years.
Knee replacements are most often done when a person’s knee joint develops severe arthritis. This is when the cartilage in the knee joint -- at the bottom of the femur (“thigh bone”) and the top of the tibia (“shin bone”) -- degrades and the joint becomes painful and usually inflamed. Cartilage acts as padding in the knee joint and to decrease friction as the knee moves. When a person loses most of the cartilage in the knee this can be described as “bone on bone” arthritis and can require a TKA. Most of the time this loss of cartilage is due to wear and tear and is described as osteoarthritis. In some cases this can be caused by an inflammatory condition called rheumatoid arthritis or trauma like a motor vehicle accident.
Knee replacement surgery was first performed in 1968. Since then, improvements in surgical materials and techniques have greatly increased its effectiveness. Recently more and more surgeons are utilizing robotic guided surgical techniques and generally with excellent outcomes.
In a traditional TKA the surgeon uses preoperative x-rays, intraoperative anatomical landmarks, and manually positioned alignment jigs to guide bone cutting and implant positioning. These handheld techniques can lead to less reliable alignment-guide positioning, inadvertent sawblade injury to the knee muscles and ligaments, and limited ability to fine-tune the implant positioning. Suboptimal implant positioning may lead to poor functional recovery and reduced implant survivorship. (At this point I should note that I work with many surgeons who have done hundreds or thousands of these traditional TKAs with great clinical outcomes.)
Robotic TKA uses computer software to convert anatomical information into a virtual patient-specific 3D reconstruction of the knee joint. The surgeon uses this virtual model to plan optimal bone cutting and implant positioning based on the patient’s unique anatomy. An intraoperative robotic device helps to execute this preoperative patient-specific plan with a high level of accuracy. The action of the sawblade is confined to the preoperative surgical plan which limits soft-tissue injury and bone trauma.
A 2019 systematic review about robotic total knee replacement found the following:
If you are considering getting a TKA there is clearly a lot of evidence that robotic TKA are effective and in some ways superior to a traditional TKA. That being said, there are many other factors to consider when looking for a surgeon to do your TKA including:
Once you've made your decision don't forget the importance of rehab! All of our physical therapists are experts in both pre and post op knee replacement rehab. For more information about what to do once you've made this big decision, check out this informational page and reach out to one of our clinics to set up an appointment!
Eric Hanyak, PT, DPT
There's a term we use in physical therapy called "respect the healing process." I've decided to shed a little more light on what we mean by this. Ultimately, the body is supposed to go through certain processes after an injury. These phases are inflammation, proliferation, and remodeling. Each phase has its frustration with respect to our patients. Contrary to popular belief, physical therapy will not make any of these phases go FASTER.
The inflammation phase is the immediate response to an injury. It is the swelling and the PAIN! Physical therapy works to help manage this phase through soft tissue work, light joint mobilizations, TENS units, exercise for facilitation and activation of surrounding musculature, gradual return of range of motion and more. The goal of getting into physical therapy this early is so that we can be prepared to move into the next phase: proliferation.
The proliferation phase is when most of the scar tissue will form. Scar tissue is a key component to healing. Whatever tissue we injured NEEDS scar tissue to heal. It reinforces the injured tissue. During this phase, physical therapy targets progressive loading of muscle and tendon structures through exercise. These techniques coupled with hands on work will help reduce excessive scar tissue formation. These treatments help prepare us for the last phase: remodeling.
The remodeling phase is when we restructure the scar tissue to align appropriately with the component it is trying to heal as well as increase exercise demand and tolerance for the surrounding areas. For example, if the achilles tendon was injured or slightly torn, we will emphasize exercise and hands on work to promote the vertical nature of the fiber alignment in the achilles tendon. This is also achieved with select tissue loading that is usually more weightbearing and functional.
This is the phase where physical therapy transitions to a routine more targeting your goals. If you want to get back to hiking, we will start lunges and squats. If you want to get back to running, we would start light plyometric and speedwork. These exercises are built upon the exercises you've been doing in the proliferation phase. As you can see from the chart above, this is the longest phase of healing. I always like to tell my patients that once you injure a structure or tissue once, you are at a greater risk of injuring it again. Physical therapy will give you all the keys and exercises necessary to reduce this risk as much as possible!
The phases of healing are overlapping in nature but never to be rushed. Physical therapy guides each patient individually through inflammation, proliferation and remodeling to ensure the best recovery and reduce your risk of re injury. A key component during your physical therapy experience at Altitude is that we will identify how you injured yourself in the first place which I have found is the best approach to not letting it happen again! Remember, you can start physical therapy even BEFORE you get injured, too! :-)
For more detailed description of the phases of healing, please see the image above or visit: https://www.physio-pedia.com/Soft_Tissue_Healing
Lisa Corken, PT, DPT
Bob Cranny, PT