Physical Therapy for Total Knee Replacement
The main goal of rehabilitation following a total knee replacement, also known as an arthroplasty, is to protect the reconstructed area and progressively maximize functional movement. Each patient will progress at a different rate depending on their comorbidities, pre-surgical range of motion (ROM), age, and rehabilitation compliance. It should be emphasized that the completion of the criteria is more important than the timeline that is outlined in each stage. One can only safely progress to the next stage if all criteria are met, if not then the patient will remain in that particular stage.
There are variations to each patient’s recovery, some may be discharged the same day while others may need to stay up to three (3) days in the hospital. This will depend on health status and ability to complete ambulation with an assistive device. It is worth noting that if there is limited flexibility and motion in the knee before surgery, there will be limitations afterward.
Physical Therapy for Total Knee Replacement: Discharge-2 weeks
The main areas of focus during the first two weeks after a TKA are managing pain, decreasing swelling, promoting skin integrity at the incision site, and promoting muscle activation of the quads and hamstrings. It is integral to follow a home program that pays particular attention to improving strength and mobility during this time. Movement will promote increases in range of motion which will in turn decrease swelling and relieve pain in the area (by increasing blood flow and nourishment to the area).
An important goal is to eliminate the need for an assistive device as quickly as possible. This will allow you to work on body awareness (proprioception), balance, strength, and returning to a normal gait pattern. The sooner the quads, hamstrings, and other muscles around the knee are able to activate and and controllably contract, the sooner the assistive device can be removed from ambulation training. Quad sets and ankle pumps are exercises used to initiate muscle activation and prevent pooling of blood in the lower extremities. Muscle activation provides the necessary venous pressure to pump blood back to the heart.
Benchmarks: Reduced swelling, reduced pain, 90 degrees of knee flexion, and full knee extension by 2 weeks, wean from assistive device(s)
Physical therapy for Knee Replacement: Weeks 3-6
The physical therapist will continue to focus on strengthening the quads, hamstrings, and hip muscles. Strengthening these muscles will help to improve walking ability and progressing from a walker or crutches to a cane (either single point or quad). By the end of week 6 it is possible you will be able to walk without an assistive device. Sit to stands will be done to increase strength of the quads and glutes as well as working to obtain greater knee flexion ROM. Resistive exercises will be initiated as tolerated, as long as all criteria are met for the first phase.
More aggressive ROM exercises can be used, and knee flexion should progress to between 100-110 degrees. A tool frequently used in PT is a stationary bike as this allows you to gradually bend your knee, going from rocking back and forth to eventually around in a full circle.
Benchmarks: 100-110 degrees of knee flexion, eliminate use of assistive device, voluntary quadriceps control, minimal inflammation
Physical therapy for Total Knee Replacement: Weeks 7-12
During this phase there will be more emphasis on strength training than ROM. Balance and stability will also be focused on, these will be aimed at being activity specific (activities you do in your daily life that may have been hindered by the TKA). There will be exercises focusing on ascending and descending stairs and lateral/multidirectional movement.
Endurance is an important part of recovery, a walking, biking, or swimming program will likely be recommended. Swimming and biking are recommended because they increase cardiovascular endurance and decrease impact of the joints.
Benchmarks: AROM without pain, minimal to no pain or swelling, 4+/5 for LE manual muscle tests (MMT), 120 degrees of knee flexion, no extension lag in SAQ or SLR
Physical therapy for Knee Replacement: Weeks 13-16
This stage will provide more activity and sport specific exercises, such as running, cutting, agility training, and plyometrics. There will be a lot of multidirectional movement with running, jumps, and plyometrics. Running is likely to be initiated during this phase for most patients. The focus will be on correct form vs. speed or pace.
Patients are encouraged to continue their fitness activity outside of the clinic to help aid in their rehabilitation.