Ligament surgery – ACL

Ligament surgery – ACL

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There are several major ligaments that stabilise the knee and can be damaged by a sporting injury or trauma. The most common to be injured are the cruciates and the collaterals.

The Anterior Cruciate Ligament – ACL

An injury to the ACL is the most common reason for ligament surgery in the knee. It is a major stabilising ligament and without it functioning properly, patients can find it difficult to continue with their sports and exercise, especially if cutting or pivoting movements are required.

Other structures including ligaments, tendons menisci and even nerves can be damaged along with the ACL. All of these can be assessed with a clinical examination and imaging including x-rays and an MRI.

Most patients describe a popping noise after landing awkwardly or twisting while playing sport. While an ACL rupture can happen during contact with another player, it is more commonly a non-contact injury. The knee swells within a few hours but the level of pain is variable for different people. After the knee has settled down, it tends to feel unstable or as if it is going to give way with running or even walking and turning.


The simple combination of resting the leg, using ice, compression and elevation will help to settle the knee down. Anti-inflammatory medications such as Ibuprofen or Voltaren can help with both pain and swelling.

It is then best to see a sports physiotherapist and your GP to confirm the diagnosis and begin treatment. Your GP can order an MRI and refer you to an Orthopaedic specialist for advice and management. The Physiotherapist will be vital whether you need surgery or not. They will work with you to regain a full range of motion and get rid of the swelling which is necessary for the knee to be functional and a requirement for surgery.


  • Young patients wanting to maintain an active lifestyle
  • Patients wanting to return to twisting sports – AFL, soccer, rugby, netball
  • Patients with an occupation where they depend on their knee not giving way – scaffolders, roofers, firemen, policemen


You are likely to go home on the same day or after one night in hospital.

ACL reconstruction surgery is a keyhole (arthroscopic) procedure.

A new ligament is fashioned from your own hamstring or patella tendon. This is then passed through tunnels that are drilled in your femur and tibia bones.

The graft can be fixed in a number of ways and can be patient dependent. The new graft takes about 6 months to heal to the bone.

Any other damage in the knee, such as a meniscal tear, is dealt with at the time.

After the operation

You are likely to have just bandages over your dressings and no splint unless there was other damage that needs protecting.

The physiotherapist will check you are safe using crutches and give you some simple exercises for your knee.

You will go home with simple tablet painkillers.

The wounds just need to be kept dry with the waterproof dressings intact. They need minimal input but if there is any redness or oozing, please contact Dr Negus or your GP.

For comfort, the knee should be iced for 20 minutes at a time and a compression bandage can be used. Please enquire about combined compression/ cooling devices such as GameReady which can be hired.

Your physiotherapy will be organised for you to start in the first week after surgery.


The physiotherapy led rehabilitation is crucial to the success of the procedure. It needs to be started as early as possible and your exercises need to be a daily part of your recovery schedule.

The early aim is to regain range of motion, reduce swelling and achieve full weight bearing.

The remaining rehabilitation will be supervised by a physiotherapist and will involve activities such as exercise bike riding, swimming, proprioceptive exercises and muscle strengthening. Cycling can begin at 2 months, jogging can generally begin at around 3 months. The graft is strong enough to allow sport at around 6 months however other factors come into play such as confidence, fitness and adequate fitness and training. 

Professional sportsmen often return at 6 months but recreational athletes may take 10 -12 months depending on motivation and time put into rehabilitation. 

The rehabilitation and overall success of the procedure can be affected by associated injuries to the knee such as damage to meniscus, articular cartilage or other ligaments. 

The following is a more detailed rehabilitation protocol useful for patients and physiotherapists. It is a guide only and must be adjusted on an individual basis taking into account pain, other pathology, work and other social factors. 

Acute (0 – 2 Weeks)


  1. Wound healing 
  2. Reduce swelling 
  3. Regain full extension 
  4. Full weight bearing 
  5. Wean off crutches 
  6. Promote muscle control 

Treatment Guidelines 

  1. Pain and swelling reduction with ice, intermittent pressure pump, soft tissue massage and exercise

  3. Patella mobilisation 
  4. Active range of motion knee exercises, calf and hamstring stretching, contraction (non weight bearing progressing to standing), muscle control and full weight bearing. Aim for full extension by 2 weeks. Full flexion will take longer and generally will come with gradual stretching. Care needs to be taken with hamstring co contraction as this may result in hamstring strains if too vigorous. Light hamstring loading continues into the next stage with progression of general rehabilitation. Resisted hamstring loading should be avoided for approximately 6 weeks.
  5. Gait retraining encouraging extension at heel strike.
Stage 2- Quadriceps Control (2-6 Weeks)


  • Full active range of motion 
  • Normal gait with reasonable weight tolerance 
  • Minimal pain and effusion 
  • Develop muscular control for controlled pain free single leg lunge 
  • Avoid hamstring strain 
  • Develop early proprioceptive awareness 

Treatment Guidelines

  1. Use active, passive and hands on techniques to promote full range of motion
  2. Progress closed chain exercises (quarter squats and single leg lunge) as pain allows. The emphasis is on pain free loading, VMO and gluteal activation.
  3. Introduce gym based exercise equipment including leg press and stationary cycle 
  4. Water based exercises can begin once the wound has healed, including treading water, gentle swimming avoiding breaststroke
  5. Begin proprioceptive exercises including single standing leg balance on the ground and mini tramp. This can progress by introducing body movement whilst standing on one leg
  6. Bilateral and single calf raises and stretching 
  7. Avoid isolated loading of the hamstrings due to ease of tear. Hamstrings will be progressively loaded through closed chain and gym based activity

Stage 3- Hamstring/Quadriceps Strengthening (6-12 Weeks)


  1. Begin specific hamstring loading
  2. Increase total leg strength 
  3. Promote good quadriceps control in lunge and hopping activity in preparation for running

Treatment Guidelines 

  1. Focal hamstring loading begins and is progressed steadily throughout the next stages of rehabilitation
    • Active prone knee flexion which can be quickly progressed to include a light weight and gradually increasing weights 
    • Bilateral bridging off a chair. This can be progressed by moving onto a single leg bridge and then single leg bridge with weight held across the abdomen 
    • Single straight leg dead lift initially active with increasing difficulty by adding dumbbells 

With respect to hamstring loading, they should never be pushed into pain and should be carefully progressed. Any subtle strain or tightness following exercises should be managed with a reduction in hamstring based exercises
  2. Gym based activity including leg presses, light squats and stationary bike which can be progressively increased in intensity as pain and control allow. It is important to monitor any effusions following exercise and if it is increasing then exercise should be toned down 
  3. Once single leg lunge control is comparable to the other side hopping can be introduced. Hops can be made more difficult by including variations such as forward/back, side to side off a step and in a quadrant 
  4. Running may begin towards the latter part of this stage

    Prior to running certain criteria must be met

    • No anterior knee pain 
    • A pain free lunge and hop that is comparable to the other side 
    • The knee must have no effusion 
    • Before jogging start having brisk walks, ideally on a treadmill to monitor landing 
    • Action and any effusion. This should be done for several weeks before jogging properly
  5. Increased proprioceptive manoeuvres with standing leg balance and progressive hopping based activity 
  6. Expand calf routine to include eccentric loading 
Stage Four-Sport Specific (3-6 Months)


  1. Improve leg strength 
  2. Develop running endurance speed, change of direction 
  3. Advanced proprioception 
  4. Prepare for return to sport and recreational lifestyle

Treatment Guidelines 

  1. Controlled sport specific activities should be included in the progression of running and gym loads. Increasing effusion post running that isn’t easily managed with ice should result in a reduction in running loads 
  2. Advanced proprioception to include controlled hopping and turning and balance correction 
  3. Monitor potential problems associated with increasing loads 
  4. No open chain resisted leg extension exercises unless authorised by your surgeon


Stage Five-Return to Sport (6 Months Plus)

A safe return to sporting activities 
Treatment Guidelines 

  1. Full training for 1 month prior to active return to competitive sport 
  2. Preparation for body contact sports. Begin with low intensity one on one contests and progress by increasing intensity and complexity in preparation for drills that one might be expected to do at training 
  3. To improve running endurance leading up to a normal training session 
  4. Full range, no effusion, good quadriceps control for lunge, hopping and hop and turn type activity. Circumference measures of thigh and calf to within 1 cm of other side