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Anterior Cruciate Ligament ACL Reconstruction

This information has been designed to give you a basic understanding of your anterior cruciate ligament operation and what to expect during your hospitalisation. Please keep in mind that this is a guideline only and that each individual has different needs, so you may progress at a different rate to that which is outlined.

Your Orthopaedics SA specialist will be happy to address any questions that might arise after reading this booklet.


The anterior cruciate ligament is the most commonly disrupted ligament in the knee. Our understanding of the anterior cruciate ligament and its importance to knee stability has increased greatly over the past 20 years, as has our ability to diagnose and treat this injury.

The normal anatomy of the knee is shown below. The cruciate ligaments and the collateral ligaments provide stability to the joint. The “menisci” function not only as shock absorbers but also enhance joint lubrication and nutrition of the articular cartilage. The articular cartilage lines the inside of the knee joint and allows for its smooth movement. It is a shiny white material that acts as a bearing surface. This articular cartilage is very different from the meniscal cartilages (or menisci, mentioned above).

When the anterior cruciate ligament is torn it is commonly associated with the disruption of one or more of the following:

  • Medial Meniscus
  • Lateral Meniscus
  • Medial Collateral Ligament
  • Articular Cartilage-Chrondal Injury

Injuries to the anterior cruciate ligament occur most often with athletic activities (especially Football and Netball), but may be ruptured in work injuries or non-athletic activities. The injury can occur without contact and often is associated with a sudden change in direction or a sudden change in speed (a deceleration injury). It may also occur with the body falling over a fixed leg or with a hyperextension injury to the knee.

When the injury occurs you may hear an audible ‘pop’ or feel the knee ‘tearing’ inside. Many people describe the knee “coming apart then popping back”. This is usually followed by difficulty walking, and progressively decreasing motion as the swelling develops. If untreated a significant number of knees give future trouble in the form of instability and giving way. This is particularly so on uneven ground or when performing twisting or turning manoeuvres. Many people describe a feeling of not being able to trust the knee.

Treatment for injuries of the anterior cruciate ligament cannot be standardised because of individual differences in injury patterns and because of different expectations of patients in regard to return to sporting activities.

In patient’s who see sport purely as recreation and who would consider giving it up if it meant that an operation may be required, a hamstring rehabilitation program may provide a satisfactory knee causes little trouble in their daily lives. For those patients who live for their sport and can’t adjust their lifestyle, surgical reconstruction offers the best chance of return to their previous level of activity.

Patients with an old anterior cruciate ligament rupture need to avoid recurrent giving way and buckling. If these episodes are associated with pain and swelling, the knee can develop progressive wear and tear arthritis. Patients in this situation need to ether consider the option of surgical reconstruction or change the demands that they are placing on their knee.

About the Reconstruction

Reconstruction of the anterior cruciate ligament is a complex procedure and there are many different ways to reconstruct it.

The preferred method, at this time, is to use a portion of tendon from elsewhere as a graft. In most cases this means using the middle third of the patellar tendon or the hamstring tendons. Artificial ligaments are currently available but have not stood the test of time.

The technique for reconstructing the anterior cruciate ligament has improved in the last ten years and can now be done in an “arthroscopically aided” manner. This does not mean that there are no incisions however, because the graft has to be taken in a standard ‘open’ operation. The knee joint itself, however, is usually not opened as all the work in the knee can be done via the arthroscope. This allows for less pain, a shorter hospital stay, and an earlier and better range of knee motion. Most importantly this means less wasting of the quadriceps and hamstring muscles post-operatively and an earlier return to normal knee function.

The Risks Involved

As with any surgical procedure complications can occur.


There is a risk of infection (about1%) and this may require treatment with antibiotics or even further surgery.

Ongoing Instability

There is a risk of ongoing instability in the knee, even with surgery (5-10%) post operation.


There is a risk of stiffness in the knee and occasionally a further arthroscopy is required to address scar tissue in the knee joint.


You may experience numbness adjacent to the scar for some months after surgery and also feel some discomfort when kneeling for up to twelve months.

Associated Meniscal Tears

These generally need to be dealt with even if a reconstruction is not being considered. A meniscal tear should be treated early so as to prevent future damage to the articular surfaces. As soon as the knee has settled down after meniscal surgery (generally at about 1 week) a rehabilitation program can be commenced to strengthen the quadriceps and to regain knee function.

Some menisci can be repaired, again with the aid of the arthroscope. If this is possible it is preferable to do this, rather than to resect part of the meniscus, particularly in the anterior cruciate deficient (unstable) knee. Loss of part or all of a meniscus does increase the wearing in the knee (osteoarthritis). Despite the advantages of meniscal repair however, it is generally not performed unless the ACL is to be reconstructed at the same time.


The anterior cruciate ligament is a major and important ligament in the knee which is commonly injured. Treatment depends on the exact nature of the injury, the nature of any associated injuries and the lifestyle of the patient and their future aspirations in regard to sport.

In those patients who are willing to alter their lifestyle a knee rehabilitation program may be adequate, but the keen athlete may prefer to have his/her knee reconstructed to get back to sport. With the advent of better operative procedures to reconstruct this ligament such as have been developed in the last ten years, the problems that used to be associated with this form of surgery are less common and the functional results are better.

In general 90% of those undergoing reconstruction will be able to return to their previous sport and some 70% will be able to compete at their previous level.

Hospital Admission

Following admission to hospital you will be seen by the anaesthetist. The operation usually requires a general anaesthetic.

When you awake following the operation you will have some discomfort in your knee and you will be given appropriate pain relief for this. You will have an intravenous line in one arm and sometimes a drain from the site of the operation, which will be removed the next day. You will be attended by the physiotherapist who will teach you exercises and when you are comfortable you will get up and about. A splint is usually required. The physiotherapist may place your knee in a Continuous Passive Motion Machine (CPM) if you are having trouble bending it.

Length of stay

Reconstruction of the anterior cruciate ligament is now an everyday procedure thanks to the very major advances in techniques that have occurred over the last decade. Therefore only a short stay of one or two nights in hospital is required.

Prior to going home you will be given a sheet of instructions and exercises, which you must do, regularly at home. Arrangements will be made for you to see a physiotherapist after your postoperative appointment, which is approximately two weeks after discharge from hospital.

You will also be given pain-relieving tablets to use at home as necessary.

Going Home


When you leave hospital you will be walking with the aid of crutches. Crutches are usually only necessary for the first 2-3 weeks but depending on your surgery may be required for 6 weeks.


You will usually wear a splint on your knee for the first 2 weeks or until you regain good muscle control. Longer periods up to 6 weeks are sometimes necessary.


You will have made a post-operative appointment to see your Doctor approximately 2 weeks after surgery. Any stitches you have will be removed at that appointment if necessary.


During this time you need to continue to do the exercises that you have been taught by the physiotherapist, before leaving the hospital. It is important to work on getting the knee fully straight.


Swelling and discomfort is expected. Simple analgesia should cover this. Fever, an offensive discharge from the wound, or pain that is not controlled with simple analgesia, may indicate an infection and should be reported. Infection is a rare complication but treated early rapid recovery can be expected.

Return to work

If you have a sedentary job you will usually require one to two weeks off work but if your job is more physical you will require up to twelve weeks off work.


After six weeks you will be reviewed again and begin a graded Rehabilitation Program, which will last for several months under the guidance of a physiotherapist. Usually pool exercises are advised.

Normal activity

You will return to normal activity reasonably quickly following this, however, your knee may not regain a full range of movement for several weeks. You should not consider returning to competitive sport for at least nine months following the operation. If you return to twisting sports before this you risk rupturing the graft before it has healed.

Rehabilitation after surgery

It is important to adhere to the Rehabilitation Program to ensure that maximum benefit is derived from your knee reconstruction operation. Your program may be altered depending upon other surgery performed.

First 3 days

During this time you will receive regular pain medication and be encouraged to move your ankle and toes. Some generalised tingling of the foot is common in the first few days from the tourniquet, which was in place around your thigh during the operation. Try to elevate your leg as much as possible to reduce swelling.

First 3 weeks

The emphasis during this period is to regain the range of motion in your knee.

Take your knee out of the splint (if applicable) and move it into straight alignment and then bend it up gently as much as you can. Do not force the knee but rather use your own muscles or let your leg dangle over the edge of a bench.

Your Doctor or Physiotherapist will instruct you with exact exercises.

4 th to 8 th week

During this time you will be allowed to commence weight bearing and walking without additional support. Be careful not to twist or jar the knee, as the new ligament is still healing into the bones above and below the knee joint. Walk in a straight line.

The emphasis during this time is to build up your quadriceps and hamstring muscles with static exercise with plenty of repetition.

Exercise in a swimming pool with you pushing your knee out straight and bending it against the resistance of the water may be helpful.

Three months onwards

During this time you will regain a normal walking pattern but will still need to be careful not to twist the knee excessively or partake in vigorous activity. It is still too early to return to sport, until directed by your Doctor.

Continue building up your quadriceps and hamstring muscles as well as maintain a full range of motion of the knee joint.

Swimming and exercise bicycle riding are good exercises to maintain fitness.

Return to sport

DO NOT return to sporting activity until allowed by your Doctor and Physiotherapist.

It takes at least nine months for your reconstructed ligament to reach maximum strength.

Hydrotherapy Program

Be guided by your physiotherapist to progress these exercises.

1. Warm-up Walk slowly the length of the pool

  • forwards
  • backwards
  • sideways

Increase the size of steps

2. Heel to bottom

  • Stand facing the pool wall and hold the rail. Allow knee to bend so that your heel approaches your bottom, then straighten leg within comfort limits.

Progression: Use ankle float

3. Leg Curl

  • Stand with back to corner of pool. Hold rail either side for support. Allow leg to bend at hip. Alternately bend and straighten knee within comfort limits.

Progression: Use ankle float

4. Donkey Kick

  • Stand facing corner of pool. Supporting leg slightly bent, other leg also slightly bent, kick gently maintaining the slight bend in the leg. Return to original position.

5. Quarter Squats

  • Stand facing pool wall, holding rail with both hands, feet pointing slightly outwards and just wider than shoulders width apart, perform a slight squat.

Knees must be pointing in same direction as feet and directly above them.

Progression: Very gradually increase depth of squat, but no further than thighs being horizontal and /or move to shallower water.

6. Kicking (with or without flippers)

  • Put flippers on both feet. Lie on stomach/back and kick yourself up and down the pool. Keep your head out of the water and feet below the water.

7. Running over a Tyre tube

  • Lie over a tube so that hips are just in the water. Take large running strides with alternate legs so that you are moving forwards.

8. Straight leg lifts

  • Stand with your back against the side of the pool with flippers on. Keep knees locked straight, lift leg up and down. Keep foot turned out slightly.

9. Scissor Exercise

  • In the corner, keep knees straight legs forwards and backwards. Then scissor legs out and in, closing legs in the middle. Keep legs low in the water.

10. Running

  • Stand facing the pool wall. Run, kicking your feet up behind you.

11. Cycling in the corner

  • Pull down with your feet.

12. Tube Striding

  • In rubber tube, +/- sling underneath bottom. Keep knees together, thighs horizontal, bend and straighten lower legs, pulling yourself forwards using your feet/ calves/ hamstrings.

13. Tube Scissoring Float in tube.

  • Scissor legs quickly out sideways then slowly bring in to propel yourself forwards.
  • Scissor legs quickly in and then slowly out to propel yourself backwards.

14. Feet Pull

  • Lie in the water face up with both feet hooked under the rail, holding 2 kickboards against chest. Bend knees and use feet to pull whole body towards the wall and then push out. Don’t let feet come out from behind the rail.

ACL Reconstruction – Weeks 0-2


These are to be done approximately 3x per day, aiming for 10 repetitions each. It is a good idea to ICE the knee for 20 minutes, as this will help reduce pain and swelling.

1. Ankle Movement

  • Move your feet up and down, in and out and in circles clockwise and anti-clockwise. This will help prevent blood clots.

2. Deep Breathing

  • Important for the first few days post-operatively after the anaesthetic and whilst you are on strong pain relief. Make sue the air goes to the base of the lungs when you breathe.

3. Flexion of the Knee

  • Gently bend the knee up towards your chest, keeping the heel on the bed, and then straighten again.
  • Do not force the movement. Never force your knee to bend beyond what is actively comfortable as this can dislodge or stretch the graft.

4. Static Quads

  • Tighten your thigh muscles and push your knee down flat into the bed. Hold 5 seconds. Relax.

5. Straight Leg Raise

  • Try and lock your knee straight and lift the whole leg off the bed, then slowly lower.

6. Stretching

  • Sitting on a chair bend your knee so that your heel moves as far under the chair as possible. You may use your other leg to push it further under.

7. Knee-cap Stretches

  • Support your knee over a rolled up towel, cup your hand over your knee-cap and slide your knee-cap towards your foot. Don’t squash your knee-cap.

8. Knee Straightening

  • Straighten your knee as much as possible. Gently push down on thigh (just above knee-cap) to stretch the back of the knee. Hold for a few seconds and gently push further. Continue doing exercise until you can straighten both knees the same when you stand.

9. Standing Knee Flexion

  • If Patella tendon graft.

10. Static Hamstrings

  • With your knee slightly bent, push your heel into the bed while keeping your knee bent. Hold for 5 seconds. Relax.

ACL Reconstruction – Weeks 2-6

At this stage your graft is still very immature. You may need to take great care of your knee – do not attempt any jumping, twisting, running or other vigorous activity.


Start with 10 repetitions of each, 3x per day and increase the repetitions, as the exercises become easier.

1. Quadriceps- Do not add weights to these exercises.

  • Static Quads Tighten the muscle above your knee and hold for 5 seconds.
  • Straight Leg Raise Tighten the muscle above your knee, make your knee as straight as possible and lift your leg. Hold 5 seconds then lower.

2. Side Lifts

  • a) Abduction Lie on side, operated leg up, straighten the knee of operated leg as much as possible. Keeping the muscles above your knee as tight as possible lift the leg towards the ceiling.

Progression: add kg weight

  • b) Adduction Lie on side, operated leg down. Place your un-operated leg behind the operated one, foot flat. Straighten the knee of your operated leg as much as possible and lift towards the ceiling.

Progression: add kg weight

3. Knee Bending

  • a) In a sitting position, place hands around shin of operated leg and pull your heel towards your buttocks.
  • b)Sitting on a chair bend your knee so that your heel moves as far under the chair as possible. You may use your other leg to push it further under.
  • c) Lying on your stomach, keep thigh flat-bend knee so heel moves towards buttock. You may use your other leg to push further.

4. Kneecap Mobilisation

  • Push your kneecap up and down, left and right. Massage your scars and Massage with skin cream.

5. Knee Extension

  • Sit in a chair, place your heel on another chair so that your knee is unsupported. Allow gravity to push on your knee to help straighten it.

Progression: place an open phone book over the knee.

6. Hamstring Exercises

  • a)Standing, hold onto a wall for balance, keep your knees together and bend your operated knee to 90% then lift your leg behind you a little.
  • b)In sitting, hook your unoperated foot under the ankle of your operated leg. Use the unoperated leg to resist the operated leg bending. May also be done lying on stomach.

7. Calf Raises

  • Standing, with knees straight, raise up and down on toes. Try to take even weight on each leg.

8. Co- contractions

  • With your knee slightly bent, dig your heel into the bed and hold. Now also try and tighten the quadriceps muscle (thigh) at the same time.

9. Quarter Squats

  • Stand close to a solid object, eg: table. Place hands on table. Ensure you are taking even weight on both legs. Tense muscles at front and back of your knees at the same time, slowly squat to ¼ of way down.

Information regarding your planned surgery

It is in your interest to read this carefully. It concerns what is going to happen to you in hospital. If you do not understand, you should approach your specialist or his secretary, for clarification of any point.

* If you are not correctly fasted for your anaesthetic, the operation may be cancelled or postponed until you are correctly fasted.

* If you are taking regular cardiac medications, please do not stop taking them (with the exception of aspirin, plavix and anti-inflammatory medication). Take all medications with a sip of water.


* If you do not understand the nature of the operation or the possible complications of the procedure, you should arrange to again see your orthopaedic specialist.


* You will be liable for several accounts in relation to your hospitalisation and operation. An account may be received from:

  1. The Hospital. This will include a bed fee, theatre fee and a fee for any disposable items and surgical implants used in the operation. If covered by Private Health Insurance, you should check your level of cover and the amount of rebate with the Insurance Company and hospital.
  2. The Anaesthetist. If you wish to discuss the Anaesthetist’s fee, please contact the Practice secretary for his/her name. You can then contact him/her directly.
  3. The Assistant. An assistant is required for all major cases and some lesser cases. You may find out if an assistant is required from the Practice secretary.
  4. The Pathologist. If pathology is required. (Not all cases require pathology).
  5. The Radiologist. Not all cases require radiology.
  6. The Surgeon’s fee. There is sometimes a difference between the fee charged by the doctor and the amount you can obtain from the Health Insurance Commission or your Health Fund. The difference is the “gap”. You should find out if your surgeon is using an “EZI CLAIM GAP” COVER SYSTEM, where the Private Health Fund pay for some or the entire “gap” on your behalf.