Exercise Protocols For Acl Reconstruction

The anterior cruciate ligament, or ACL, is a structure in the knee that provides stability. When this ligament is torn, an orthopedic surgeon will perform an ACL reconstruction. After surgery, the physician will order physical therapy to restore range of motion and strength to the affected knee. While many rehabilitation protocols are physician-specific because of the particular surgical procedure, there are several universal guidelines.

ACL Surgery

An ACL reconstruction is not a one-size-fits-all procedure. There generally are two main types of surgical options, an autograft and an allograft. An autograft takes a tendon from the patient's own body to replace the deficient ACL, whereas an allograft uses a cadaver tendon. The type of procedure used will determine the focus of rehabilitation and the length of recovery. Typically, an allograft involves a shorter recovery time because the patient doesn't have to simultaneously heal from surgery to the opposite leg from which the tendon was harvested.

Early Therapy

The focus of early physical therapy is on knee extension range of motion, quadriceps muscle function and reduction of swelling. Reducing swelling in the knee is of particular importance because swelling inhibits the quadriceps muscles from functioning properly. When the quadriceps muscles are weak, the knee buckles easily and it is difficult to lift the leg independently. Achieving full knee extension early is important in normalizing gait and the capacity to run later on.

Six to Eight Weeks Post-Surgery

Typically six to eight weeks after surgery, cardiovascular activity is resumed, but with low impact machines such as the elliptical trainer, stationary bike and stair climber. The physician will start to encourage more weight-bearing exercises during this time period such as squatting and single limb balance activities. It is unsafe to perform activities that involve quick changes of directions because the graft to bone site is still not healed.

What to Expect

The physician will ultimately guide the rehabilitation protocol based on the type of surgical procedure. If accessory structures such as the MCL, or medial collateral ligament, are damaged at the same time as the ACL, the exercise protocols will be different. Generally, an athlete will return to full sport participation within six to nine months, but it may be dependent on the risk of that sport for re-injury.