Pre-surgery conditioning, known as prehabilitation, is an exercise and education program designed to prepare the body for a major operation like a knee replacement. This conditioning focuses on building strength and maintaining joint mobility in the weeks or months leading up to the procedure. Maximizing physical capacity before surgery sets a foundation for a more efficient recovery afterward.
The Role of Prehabilitation in Surgery Success
Pre-operative exercises physically and psychologically prepare the body for the stress of surgery and the subsequent rehabilitation phase. This proactive approach helps patients build muscle strength and endurance to draw upon once the procedure is complete. Research has shown that patients who engage in prehabilitation may reduce their need for inpatient physical therapy by a significant percentage, in some studies up to 73%. Strengthening the muscles around the knee, particularly the quadriceps, counteracts the muscle atrophy that often occurs during the period of reduced activity before and immediately after surgery, leading to a quicker recovery and potentially a shorter hospital stay.
Essential Strengthening Exercises
The focus of pre-operative strengthening is the quadriceps and hamstrings, the major muscle groups that stabilize the knee joint. These exercises should activate the muscles without causing excessive strain on the already compromised joint.
Quad Sets (Static Contractions)
Quad sets target the quadriceps muscle on the front of the thigh and can be performed while lying down with the leg extended. To perform this exercise, actively tighten the thigh muscle by pushing the back of the knee down onto the surface below. Hold this contraction for five to ten seconds, focusing on maximal muscle engagement, and then completely relax.
Straight Leg Raises
Straight leg raises build strength in both the quadriceps and the hip flexors, which are important for regaining the ability to lift the leg after surgery. Begin by lying on your back with the non-surgical knee bent and the foot flat on the floor, keeping the leg being exercised straight. Tighten the thigh muscle, then slowly lift the entire leg a few inches off the floor, keeping the knee straight throughout the movement. Hold the leg briefly at the peak of the lift before slowly lowering it back down with control.
Mini Squats
Mini squats engage the quadriceps and glutes, which are key for stability during walking and standing. Stand upright with your feet about hip-width apart, holding onto a stable surface like a counter or chair back for balance. Slowly bend the knees, lowering the hips just a few inches, as if starting to sit down, keeping your chest up and your knees aligned over your toes. The depth of the squat should be limited to a comfortable range that avoids increasing knee pain.
Range of Motion and Flexibility Drills
Maintaining the existing range of motion is paramount before knee replacement, as flexibility tends to decrease with increasing joint stiffness. The goal of these drills is to gently preserve mobility, not to aggressively stretch the joint.
Heel Slides
Heel slides are an effective exercise to maintain knee flexion, or bending, without placing weight on the joint. While lying on your back with both legs extended, gently slide the heel of the affected leg along the floor toward the buttocks, bending the knee. Slide the heel only as far as is comfortable, pausing at the point of tension, then slowly return the leg to the starting position.
Ankle Pumps
Ankle pumps help promote circulation in the lower legs. This movement assists in preventing blood clots and reducing swelling, which are concerns before and after surgery. While sitting or lying down, flex the foot upward, pulling the toes toward the head, and then point the foot downward.
Seated Knee Extension
Seated knee extensions work to maintain the ability to straighten the knee, which is necessary for a normal gait. Sit upright in a sturdy chair with the feet flat on the floor, then slowly lift the foot of the affected leg until the knee is straight. Hold the leg straight for a few seconds using the thigh muscles, and then slowly lower the foot back to the floor.
Safety Guidelines and When to Stop
Before starting any exercise program, consult with your orthopedic surgeon or a physical therapist, who can tailor a routine to your specific medical condition and provide guidance on frequency. It is important to distinguish between expected muscle fatigue and pain that signals joint irritation or injury. Muscle fatigue may feel like a deep sensation that subsides quickly after stopping the exercise. If you experience sharp, stabbing pain or an increase in joint discomfort that lasts after the activity, stop that specific exercise immediately or reduce the number of repetitions.