Rehabilitation After Anterior Cruciate Ligament Reconstruction
After anterior cruciate ligament reconstruction, the aim is not simply to “move the knee”, but to protect the graft, restore full extension, recover quadriceps control, normalize gait, rebuild balance, and gradually return the patient to running, jumping, and sport-specific movement.
Rehabilitation after anterior cruciate ligament reconstruction depends on graft type, fixation strength, tissue quality, associated meniscal injury, cartilage injury, collateral ligament injury, and any additional procedures performed at the same operation. Therefore, progression should not be based on the calendar alone. The key clinical criteria are pain, effusion, range of motion, strength, gait quality, limb alignment, and patient confidence.
- increasing pain or swelling after exercise;
- a hot knee, fever, wound discharge, or offensive wound smell;
- calf pain, sudden lower-leg swelling, shortness of breath, or chest pain;
- sudden locking, new catching, or a new feeling of instability;
- loss of full extension or progressive restriction of flexion;
- a giving-way sensation during walking or exercise.
Rehabilitation phases
Exercises
The exercises below are arranged from early to advanced. They should not all be performed on the same day. Progression is appropriate only when the previous exercise does not cause pain, effusion, limping, or loss of knee control.
Active assisted knee motion
The patient sits on a high couch with both feet off the floor. The opposite leg supports the operated leg and helps gently extend and flex the knee. The main early goal is full extension without forceful movement.
Wall squat with ball
A large exercise ball is held between the lower back and the wall. The feet are placed slightly in front of the knees. Squat depth is increased gradually, without pain, effusion, or inward collapse of the knee.
Backward walking
The patient walks backward on a treadmill at approximately 1–2 km/h while holding the handrails. This helps restore full knee extension during stance phase.
Stationary bike with short pedals
The saddle height is adjusted so the knee is almost fully extended at the lowest pedal position. Start without resistance. The knee should not swell after cycling.
Step-down with visual control
Begin with a low step, approximately 10 cm. The patient slowly lowers the opposite leg forward while keeping body weight on the operated leg. A mirror is used to control foot, knee, and hip alignment.
Step-up with visual control
The patient stands in front of a step and slowly steps up while controlling knee position. Step height is increased to 15–20 cm only when the movement is controlled and pain-free.
Step-down test
This test assesses balance, strength, and knee control. Speed is not the priority. Smooth movement, symmetry, absence of pain, and absence of post-exercise effusion are more important.
Assisted knee flexion
The foot of the operated leg is placed on a step. The trunk moves forward gently to increase knee flexion. The position may be held for up to 10 seconds. The movement should not cause pain or effusion.
Balance with elastic band
The elastic band is fixed to a stable support. The patient stands on the operated leg while the opposite leg moves sideways. The aim is coordinated control of the hip, thigh, and knee muscles.
Balance on roller
This is a more advanced balance exercise. The operated knee is slightly flexed and the trunk remains upright. The opposite leg moves backward and sideways while the patient maintains balance.
Single-leg hops over a line
A late-stage exercise. The patient hops across a line and lands softly. It trains strength, balance, and landing control. It should not be performed if pain or effusion is present.
Balance training
The patient stands on one leg on a moving platform or unstable surface. The goal is to maintain balance without hand support and without inward collapse of the knee.
Controlled leg press
The press phase is performed with both legs, while the return phase is performed with greater control through the operated leg. The knees should not be locked in full extension. Load is increased gradually.
Objective knee strength assessment
Flexion and extension strength are assessed and compared with the opposite leg. This is useful before returning to running, jumping, and sport.
Hip extension
This exercise strengthens the gluteal muscles, which help control knee position. The patient should avoid compensating through the lumbar spine.
Square hop drills
Begin with simple two-leg hops, then progress to more complex directions. Full range of motion, adequate strength, and confident landing control are required before starting.
Step jumps
The patient jumps onto a step with both legs. Landing should be soft and symmetrical. Step height is increased only when technique is good.
Lateral step jumps
The patient jumps sideways onto a step and then down to the other side. This exercise is used only after strength, balance, and knee control have recovered.
Resisted side stepping
The elastic band is fixed around the pelvis or thighs. The patient moves sideways with controlled side steps while maintaining hip and knee control.
Single-leg long jump
A late-stage functional assessment. The operated and non-operated limbs are compared. Distance is important, but landing quality and absence of effusion after the test are equally important.
Underwater treadmill walking
This can be used after complete wound healing. Water reduces axial load and allows earlier gait training with better movement quality.
Bibliography
- Strobel MJ. Manual of Arthroscopic Surgery. Springer-Verlag Berlin Heidelberg, 2009.
- Logerstedt DS, Scalzitti D, Risberg MA, et al. Knee Stability and Movement Coordination Impairments: Knee Ligament Sprain Revision 2017.
- Massachusetts General Hospital Sports Medicine. Rehabilitation Protocol for Anterior Cruciate Ligament Reconstruction.
- Academy of Orthopaedic Physical Therapy. Clinical Practice Guideline for Knee Ligament Sprain.