Preoperative goals include control pain and swelling, restoration of normal ROM, and the development of muscle strength sufficient for normal gait and activities of daily living (ADLs).

Suggested ROM exercises include the following:

Muscle strength is developed with the stationary bicycle, elliptical cross-trainer, leg press machine, leg curl machine, and treadmill walking.

Immediate postoperative goals include control of pain and swelling, care for the knee and dressing, early ROM exercises (with an emphasis on full passive extension), activation of the quadriceps muscles, and gait training.

Inflammation is controlled swelling with elevation and cryotherapy. Narcotics are appropriate early postoperatively to control pain. Nonsteroidal anti-inflammatory drugs are avoided because they may decrease graft incorporation.

Early ROM emphasizes extension. The knee immobilizer is removed every 2-3 hours while awake. The heel is positioned on a pillow or rolled blanket or towel with the knee unsupported, and the knee is allowed to sag into full extension for 10-15 minutes. Active-assisted extension is performed by using the opposite uninjured leg and contracting the quadriceps muscles to straighten the knee from the 90-degree position to 0 degrees. Passive flexion of the knee to 90 degrees is performed with the uninjured leg while sitting.

Quadriceps exercises include isometric contractions with the knee fully extended and straight leg raises (SLRs) with the knee immobilizer on.

Following patellar tendon graft procedures, hamstring isometric contractions are also performed.

For patients who have had anterior cruciate ligament reconstruction using the hamstring tendons, it is important to avoid excessive stretching of the hamstring muscles during the first 6 weeks after surgery.

Goals during postoperative days 8-10 emphasize maintenance of full extension: The athlete continues quadriceps isometrics, SLR, active flexion, and active-assisted extension exercises. It is emphasized to continue removing one’s leg from the knee immobilizer four to six times a day for 10-15 minutes at a time to perform extension exercises.

During postoperative week 3, goals include maintenance of full extension, achievement of 100-120 degrees of flexion, and development of enough muscular control to wean from the knee immobilizer. In addition to extension exercises and passive flexion, active flexion exercises are added.

Additional muscular strengthening exercises include partial squats and toe raises. Stationary bike is used with no or low resistance.

Crutches are discontinued and the knee immobilizer is discontinued when good muscle control of quadriceps muscle is achieved.

Goals for weeks 3-4 include advancement of ROM and strengthening. Expected ROM is from full extension to 100-120 degrees of flexion. Wall slides assist with flexion. Strengthening exercises and stationary bike are continued. The elliptical machine and inclined leg presses (from 0-70 degrees) are added. For those with patellar tendon graft, seated hamstring curls are initiated (hamstring curls are avoided until week 8-10 in patients with hamstring graft). Upper body exercise machines, swimming pool walking, flutter kick, water bicycle, and water jogging promote general conditioning.

Goals for weeks 4-6 include 125 degrees of flexion pushing toward full flexion and continued strength building. The athlete continues quad sets, SLR, partial squats, toe raises, stationary bike, elliptical machine, leg presses, and leg curls. Tilt board or balance board exercises for balance and proprioception training are added.

Strengthening, general conditioning, and tilt and balance board are continued. Flexion is advanced with goal of 135 degrees of flexion. Treadmill walking without incline is commenced and road bike on flat roads permitted.

Running and agility drills are introduced. The athlete continues all of week 6-12 strengthening exercises. Straight forward and straight backward running is initiated. Athletes advance to agility drills including zig-zags and cross-over drills.

Athletes return to sport during this period. Criteria to return to sport include the following: resolution of swelling, stable knee examination, full ROM, quadriceps/hamstring muscle strength at least 80% of the normal leg (Cybex isokinetic dynamometer evaluation), KT 2000 arthrometric evaluation with a < 3-mm side to side difference, and the ability to complete a running program.

During phase 2, the athlete should achieve full nonpainful ROM, restore normal muscle strength and endurance, and return to functional activities.