Rehabilitation Guidelines for Anterior Cruciate Ligament (ACL) Reconstruction The knee is the body's largest joint, and the place where the femur, tibia, and patella meet to form a hinge-like joint. These bones are supported by a large complex of muscles, tendons, ligaments, and cartilage which allow the knee joint to function. They are subject to injury due to the significant forces passing through the knee. A ligament is tissue that connects one bone to another bone. The anterior cruciate ligament (ACL) is one of the four major ligaments in the knee. It connect the tibia to the femur. The ACL is located in the center of the knee along with the posterior cruciate ligament (PCL). The ACL's primary function is to prevent the tibia from shifting forward under the femur and to control the amount of rotation in the knee joint. Embedded in the ACL are nerve endings and mechanoreceptors, called proprioceptors, that send signals to the brain and central nervous system about the joint position of the knee. When these nerve endings are stimulated, the central nervous system activates muscles around the knee to bring the joint into a more stable position. Thus, the overall function of the ACL gives the knee joint stability during movement. There are two typical mechanisms of injury that lead to a torn ACL. The primary mechanism is a shearing of the ACL when a sudden shifting occurs between the tibia and the femur. This can occur when a person is running and attempts to rapidly slow down and change direction at the same time, or attempts to turn quickly after the foot has been planted. This is a common mechanism for injury to the knee while skiing. The second mechanism is hyperextension of the knee causing failure of the ligament from excessive stretching. Hyperextension can occur as a result of landing from a jump with the knee extended or by sustaining a blow to the front of an extended knee. 85% of patients will feel a pop at the time of injury and most will have significant swelling within two to three hours of injury. Phyiscal exam and history often demonstrate laxity or a feeling of loose restraint within the knee. An MRI is often used to confirm the injury and to determine the presence of other injuries, such as meniscal tears, cartilage lesions or other ligament injuries. Surgery is not always indicated for everyone who tears his or her ACL. In some cases it is possible to do well by following a rehabilitation program and avoiding activities that require cutting and/or pivoting movements. If surgery is chosen, the patient should undergo a preoperative physical therapy exercise program to regain normal knee range of motion, decrease pain and swelling and strengthen the musculature around the knee. This may last three to six weeks, but will allow the postoperative course to progress faster.
Surgical reconstruction involves replacing the torn ACL with a graft. The most common grafts used are the patellar tendon graft, the hamstring tendon graft, and an allograft (cadaver). The type of graft used is chosen based on many patient-specific factors and should be discussed with your surgeon. Post-operative rehabilitation is essential in optimizing your function and return to sport after an ACL reconstruction. Frequently during an ACL reconstruction, other injuries or pathologies are addressed during surgery. These additional procedures may require special post-operative precautions. The process of returning to physical and athletic activities is not based on time, it is based on the individual's ability to achieve certain milestones or criteria. The time needed to do this will vary from individual to individual. Rehabilitation with a physical therapist or athletic trainer is often needed to restore range of motion, strength, movement control and guide the athlete's return to sport. The rehabilitation guidelines are presented in a criterion based progression. Specific time frames, restrictions and precautions are given to protect healing tissues and the surgical repair/reconstruction. General time frames are also given for reference to the average individual, but individual patients will progress at different rates depending on their age, associated injuries, pre-injury health status, rehabilitation compliance and injury severity. 2
PHASE I (surgery to 4-6 weeks after surgery) Rehabilitation appointments begin 3-5 days after surgery Protect the post-surgical knee Restore normal knee range of motion Eliminate swelling (i.e. effusion) Restore leg control Range of Motion (ROM) s (Please do not exceed the ROM specified for each exercise and time period) Progression Criteria Gradually wean from crutches when there is no pain with knee locked in brace Knee brace locked for all weight bearing activities for 4 weeks Do not flex the knee past 90 Knee extension on a bolster Prone hangs Supine wall slides Heel slides (caution with posterior medial meniscus repair secondary to the semimembranosus insertion) Knee flexion off the edge of the table Quadriceps sets Straight leg raises 4 way leg lifts in standing with brace on for balance and hip strength Abdominal isometrics Upper body circuit training or Upper Body Ergometer (UBE) 4 weeks after surgery Pain-free gait without crutches No effusion (swelling) 3
PHASE II (begin after meeting Phase I criteria, usually 4-6 weeks) Progression Criteria Rehabilitation appointments begin once every 1 to 2 week Single leg stand control Normalize gait Good control and no pain with functional movements, including step up/ down, squat, partial lunge (between 0 and 60 of knee flexion) No forced flexion with passive range of motion with knee flexion or weight bearing activities that push the knee past 60 of knee flexion Avoid post-activity swelling No impact activities Non-impact balance and proprioceptive drills Stationary bike Gait drills Hip and core strengthening Stretching for patient-specific muscle imbalances Quadriceps strengthening, making sure that closed chain exercises occur between 0 and 60 of knee flexion Non-impact endurance training: stationary bike, Nordic track, swimming, deep water running or cross trainer Normal gait on all surfaces Ability to carry out functional movements without unloading the affected leg or pain, while demonstrating good control Single leg balance greater than 15 seconds 4
PHASE III (begin after meeting Phase II criteria, usually >3 months after surgery) Rehabilitation appointments are once every 1 to 2 weeks Good control and no pain with sport and work specific movements, including impact Return To Sport/Work Criteria Post-activity soreness should resolve within 24 hours Avoid post-activity swelling Impact control exercises beginning 2 feet to 2 feet, progressing from 1 foot to other and then 1 foot to same foot Movement control exercises beginning with low velocity, single plane activities and progressing to higher velocity, multi-plane activities Sport/work specific balance and proprioceptive drills Hip and core strengthening Stretching for patient specific muscle imbalances Replicate sport or work specific energy demands Dynamic neuromuscular control with multi-plane activities, without pain or swelling Patients may have advanced diagnostic and /or treatment options, or may receive educational materials that vary from this information. Please be aware that this information is not intended to replace the care or advice given by your physician or health care provider. It is neither intended nor implied to be a substitute for professional advice. Call your health provider immediately if you think you may have a medical emergency. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any question you may have regarding a medical condition. 5