Total Knee Arthroplasty (TKA), commonly known as total knee replacement, is a procedure where damaged bone and cartilage are replaced with metal and plastic components to relieve pain, typically caused by arthritis. A successful recovery relies heavily on post-operative physical rehabilitation, as exercise is the single most important factor for restoring mobility and function. These structured movements are designed to complement, but not replace, the guidance and specialized care provided by a professional physical therapist. The goal of a progressive exercise program is to strengthen the muscles surrounding the joint and maximize the range of motion of the newly implanted knee.
Immediate Post-Operative Exercises
The initial focus immediately following surgery, often starting within 24 hours, is on preventing complications and maintaining basic muscle activation. Simple, repetitive movements are performed frequently, sometimes hourly, to improve blood flow and reduce the risk of deep vein thrombosis (DVT).
Ankle pumps are performed by rhythmically moving the feet up and down, pointing the toes toward the head and then away, which contracts the calf muscles to push fluid and blood through the lower leg. Quadriceps sets involve tightening the quadriceps to push the back of the knee down toward the bed or floor, which helps re-establish the nerve-muscle connection. Holding this contraction for five to ten seconds is necessary for muscle activation.
Gluteal sets, or glute squeezes, are performed by tightening the buttock muscles and holding the contraction, which helps stabilize the pelvis and hips. Early range of motion is gently encouraged through exercises like passive heel slides. The heel is kept on the surface while the foot is slid toward the buttocks to bend the knee, often assisted by a therapist or a strap.
Early Strengthening and Range of Motion
Typically beginning in the first week or two, once initial post-surgical swelling and pain have moderated, the rehabilitation progresses to movements that increase mobility and build foundational strength. These exercises involve a greater, yet still controlled, range of motion and often the introduction of partial weight bearing.
Active assisted heel slides transition into self-directed movement, where the patient uses their own muscles to slide the heel back and forth, gradually increasing the knee’s bending capacity. Straight leg raises (SLR) are introduced to build quadriceps strength without placing undue stress on the knee joint. The leg is lifted a few inches off the bed while keeping the knee perfectly straight.
Standing mini-squats involve partial weight bearing, often while holding onto a stable surface for balance. The patient bends the knees slightly, descending only a short distance, which strengthens the quadriceps, hamstrings, and gluteal muscles in a controlled manner. Standing marches, performed while maintaining support, help re-establish a natural walking pattern and improve balance by practicing single-leg stance.
Advanced Functional Recovery Movements
As the recovery enters the intermediate phase, usually around four to six weeks post-surgery, the exercises become more dynamic. They focus on full weight bearing, endurance, and functional movements. These drills focus on mimicking real-world actions like climbing stairs and walking longer distances.
Stationary cycling is recommended for its low-impact nature, improving cardiovascular endurance and increasing the knee’s range of motion. The bike seat should be adjusted so the foot can comfortably reach the pedal with the knee only slightly bent at the bottom of the stroke, and resistance should be kept low initially. Step-ups simulate stair climbing, starting with a small platform or the bottom step. The operated leg is placed on the step and used to lift the body up, focusing on controlled movement down to strengthen the quadriceps and improve balance.
Gentle lunges can be introduced upon approval, helping to build functional strength and flexibility in a forward-moving pattern. These should begin with a small step and minimal depth, ensuring the knee of the operated leg does not move past the toes. Advanced balance drills, such as a single-leg stance, improve safety and stability during walking and pivoting movements. This involves standing on the operated leg for increasing periods, often next to a support, to challenge the muscles responsible for joint stability.
Safety Guidelines and Pain Management
Successful rehabilitation requires understanding limitations and recognizing warning signs. The goal of exercise is to create a tolerable level of muscle fatigue and mild soreness, not sharp or sudden joint pain. Any pain that feels sharp, stabbing, or localized directly at the joint should signal stopping the activity immediately.
Patients should avoid high-impact activities, such as running, jumping, or sports that involve sudden stops and starts, as these can wear down the implant components. Excessive twisting or pivoting on the operated leg, especially when bearing weight, should also be avoided to protect the new joint.
Monitoring the surgical site is a necessary precaution. Contact the surgeon or physical therapist immediately if you experience signs of infection or complication, such as:
- A fever above 101°F.
- Excessive redness that spreads.
- Significant new or worsening swelling.
- Persistent drainage from the incision.
Pain management, often involving a multimodal approach with medications like acetaminophen or nonsteroidal anti-inflammatory drugs, should be used proactively. Medications should be taken thirty minutes before exercise to allow for productive therapy sessions.