The knee is essentially a hinged joint and the anterior cruciate ligament, or ACL, one of four ligaments that connects the femur to the tibia. According to the American Academy of Orthopaedic Surgeons, the anterior cruciate ligament remains one of the most commonly injured ligaments of the knee. Rehabilitation following ACL surgery varies dramatically from individual to individual, based on the type of graft used in reconstruction. Regardless, physical therapy plays a critical role in the successful outcome following surgery.
Post-op Days 1 to 7
In general, most surgeons will allow the patient to go home on the same day following ACL surgery. According to Dr. Peter Millett, the goals for the first post operative week include controlling pain and swelling, increasing weight bearing as tolerated, achieving full passive extension and increasing knee range of motion. The patient goes home wearing a full leg knee brace and walking with crutches. Often physicians prescribe that patients use a continuous passive movement machine, or CPM, that moves the knee through flexion and extension while they lie in bed. They will also recommend cold therapy to control swelling and pain. Begin stationary bike riding, within a pain free range of motion, once the patient can get on and off the bike safely.
Week Two
The patient begins formal physical therapy two to three times per week about week two. The physical therapist will provide exercises to increase range of motion and strength. These will include isometrics for the quadriceps, straight leg raises and stationary cycling. Weight bearing progressively increases as tolerated with the knee immobilizer on. The physician will clear patients to return to work, if appropriate.
Weeks 3 to 4
The goals during this phase include maintaining full passive straightening, increasing knee flexion and increasing strength enough to wean off of the knee immobilizer. Patients may resume driving once they demonstrated adequate strength and they no longer need pain medications. Physical therapy will include more aggressive strengthening exercises performed in standing, such as mini squats and toe raises. The patient will continue to ride the stationary bike with increasing resistance and for longer durations. Patients may use some exercise machines at this time, such as the leg press and hamstring curl. Aqua therapy can prove an effective conditioning exercise safe for the patient to begin at this time.
Weeks 4 to 12
During weeks four to 12, the patient should achieve full range of motion. Single leg balancing activities, such as the tilt board, are emphasized to improve strength and coordination. Biking may be allowed outside on flat ground and walking on the treadmill is introduced. Formal physical therapy will be phased out and replaced with a home exercise program, which will continue to emphasize strengthening.
Weeks 12 to 24
During the final phase of rehab the patient will begin functional activities, light jogging and footwork agility drills, in preparation for returning to sports. According to Dr. Peter Millett, six months generally proves the soonest that the patient will be allowed to return to athletics. Returning to sports is determined on a case by case basis, by the surgeon, physical therapist and athletic trainer, who will ask the athlete to complete a series of sport specific drills.
