When the anterior cruciate ligament (ACL) has ruptured it has no ability to heal. Therefore it cannot be repaired. Surgery to treat this problem is required to replace the damaged ligament with a “new” ligament (graft).

The damaged ligament is removed and replaced with a “new” ligament, which is taken from another part of the leg e.g. hamstring tendon.

Small incisions are made around the knee joint and an arthroscope is used to see inside the knee. Whilst inside the knee, Dr Sim will also attend to other injuries that he might find e.g. meniscus tear, cartilage damage.

Holes are drilled in the tibia (shin bone) and the femur (thigh bone) so the graft can be pulled through and secured at each end.

The surgery will take between 60 minutes. You will go home the same day. You will be able to walk immediately with the use of crutches for support.

ACL reconstruction is usually very successful. Most patients recover well after surgery. Sedentary (Office) workers can return to work at about 2 weeks after surgery. Light manual workers at about 6 weeks and heavy manual workers around 3-6 months.

If the ACL rehabilitation protocol is followed, a full return to activities and sports can be achieved. This usually takes about 9-12 months.

  • Infection
  • Excessive stiffness
  • Swelling of the knee
  • Bleeding in the knee joint
  • Damage to the blood vessels or nerves
  • New injury to the knee causing rupture of the ligaments graft
  • Ongoing instability

For more information about your condition, go to: www.orthoinfo.aaos.org – click on Knee & Lower leg.


Instructions for AFTER the surgery

  • You may put full weight through your leg when walking.
  • You must use crutches.
  • Try not to limp.
  • Stop using crutches when able to walk comfortably WITHOUT a limp.
  • All wounds are closed with dissolving stitches AND covered with WATERPROOF dressing.
  • Leave bulky dressing undisturbed for 48 hours.
  • Remove bulky dressing after 48 hours and replace with elastic bandage (Tubigrip) supplied.
  • Wear elastic bandage at all times except for daily shower. NO soaking, baths or swimming till wounds are fully healed (usually 2 weeks)
  •  You will need to book the physio, this should be start 2-3 days after surgery.
  • Swelling. This is to be expected. Try to rest with the leg fully straight. A pillow under the heel will help with this. DO NOT REST WITH A PILLOW UNDER THE KNEE. Elevate the leg on a pillow or cushion while sitting. An ice pack can be used.
  • Pain. This is worst in the first 48-72 hours after surgery and gradually improves after that. You will receive a prescription for pain medication on discharge. Take the medications as required until the pain is tolerable
  • Possible temporary numbness and/or tingling around the wound site.
  • Gently start bending AND straightening your knee AS PAIN allows. Your physio will provide you with information/instructions of more exercises to do.
  • Excessive persistent pain
  • Pus discharge from wound
  • Fever
  • Excessive pain AND tenderness AND swelling in the calf.

Should any of these symptoms persist contact Dr Sim’s rooms or after hours emergency.

ACL Reconstruction Rehab Protocol




  • Decrease pain and swelling
  • Restore full extension (i.e. getting the knee fully straight)
  • Quadriceps (front of thigh muscle) activation
  • Gait training (i.e. learning to walk properly WITHOUT limping)

Exercises Suggestions

  • Your first physio appointment should be within 3 days after surgery.

ROM & Flexibility

  • Remember it is important to restore and maintain range of motion early, especially full extension. This is not harmful to the graft or its stability.


  • Use two crutches until you can walk WITHOUT a limp. Then try with one crutch. You can stop using crutches once you walk WITHOUT a limp.



  • Achieve near of full ROM in knee flexion and extension
  • Normal gait pattern
  • Quad activation
  • Full knee extension is needed for normal gait


  • You can consider driving if:
  • You are off strong prescription pain killer (Endone)
  • You are OFF your crutches
  • You have GOOD leg control (e.g. you are able to simulate and emergency braking manouvre in a stationary car without any PAIN in the knee)






  • Full and pain free knee range of motion
  • Functional quad strength

Exercise suggestions

Hydrotherapy/Pool (if required)

  • Knee ROM
  • Walking forward/backward, static lunge, lunge walking squats, side shuffles, step up/down, calf rises (2-1 foot)
  • Hip extension/flexion, adduction/abduction
  • Deep water: stride walking, cycling, flutter kick


Cardiovascular Fitness

  • Stationary bike
  • Swim – Flutter kick only
  • Treadmill – walking

9-12 WEEKS



  • Continue flexibility/stretching exercises
  • Quadriceps strength progression

Exercise Suggestions


  • Increase time, speed and repetitions of exercises
  • Pool running


Cardiovascular Fitness

  • Bike – Increased resistance and time parameters
  • Treadmill – Walk +/- incline – quick walk

12-16 WEEKS



  • Continue with flexibility exercises for the lower chain
  • Continue strengthening (including hamstrings) of all leg muscle

Exercise Suggestions

Cardiovascular Fitness

  • Bike – time and resistance
  • Treadmill – time + incline




  • Quadriceps, hamstrings and other leg muscle strengthening.
  • Proprioception training (i.e. learning to sense movement within joints AND the joint’s position)
  • Adequate cardiovascular fitness
  • Running: Progression to running may only occur once a smooth and normal pattern has been attained to prevent abnormal tissue/joint loading in the knee. Running should NOT be initiated if swelling, loss of motion or pain is present.

Exercise Suggestions

  • Continue upper body strengthening

Muscle Strength and Endurance

  • Continue with lower extremity strengthening with specific emphasis on specific deficits.





  • Agility drills should commence by introducing proper footwork, timing and speed.
  • Once you are able to successfully and appropriately run in a straight line, without difficulty, then you can progress to drills/activities where change in direction is required.
  • These drills should commence by introducing large angles and low speeds i.e. large figure 8s) and progress to more advance drills with sharper angels and increasing speeds.

Cardiovascular fitness

  • Increase distance, duration or intensity with bike, treadmill
  • Treadmill: running – Sprinting: assess springing form – should have normal pain-free rhythmic stride
  • Cycling outdoors
  • Swimming – no whip kick / breast stroke kick / frog leg kick




  • Pylometrics
  • Return to sport skills on own practice with minimal risk of injury


  • Pylometrics are exercises that enable a group of muscles to reach maximal strength in as short a time as possible. They help bridge the gap between speed and strength training.


  • 2 and 1 foot hopping with control
  • Forward and lateral hop with control and comparable distance L&R * Single limb hop for distance (within 15% of uninvolved side)
  • Single limb vertical power hop (within 15% of uninvolved side)
  • Single limb drop landing (within 15% of uninvolved side)



  • Return to competitive sport once all goals achieved


  • Physiotherapy and surgeon have declared you fit to do so


  • There are neither MANDATORY nor NECESSARY whilst playing sport if you have satisfactory completed the rehab program.
  • You may consider a knee sleeve for personal “confidence” if required