Arthroscopic Anterior Cruciate Ligament Reconstruction

ACL Reconstruction / Cruciate repair

Once a diagnosis of ACL rupture has been made and initial knee swelling and stiffness are settled, patients may need to undergo ACL reconstruction surgery to achieve full knee stability and return to sport.  Some patients can be managed with specialized physiotherapy rehabilitation allowing a return to their desired activities without surgery, but this is uncommon with competitive twisting sports.

ACL surgery is carried out under a general anaesthetic with additional local anaesthetic used at the end of the procedure.  It is performed arthroscopically (key hole surgery) to firstly take a section of tendon (usually from the same knee) that is used to replace or reinforce the torn cruciate ligament.  The tendon graft is taken from the back of the thigh in most cases (hamstring tendon graft) but sometimes the graft is taken from the patella tendon at the front of the knee.  The tendon is then passed through a bone tunnel created through the top of the tibia (shin bone) into the knee joint and then through a similar tunnel in the end of the femur (thigh bone).  The graft is then secured at either end in the tunnel with a clip and a screw.  Any surgery that is required to trim or repair cartilage damage can be undertaken at the same time.

After surgery a physiotherapist will see you to initiate early rehabilitation and ensure safe mobility, but the knee will be swollen and bruised and will require a period of relative rest for a few days.   Ice and elevation with gentle movement exercises can help reduce the swelling. 

Factors to Consider

What are the risks of surgery?

Complications are rare following ACL reconstruction but can occur.

  • Infection – the risks of infection are low based on only small incisions being used and the surgery being relatively short however a superficial infection can occur that can be treated successfully with oral antibiotics.  Very rarely a deeper infection in the joint may require a further operation.
  • Deep Vein Thrombosis (DVT) – is rare following this type of surgery but does sometimes occur (>1%).  During surgery precautions are taken to minimise the risk by using pumps on your calves and you are encouraged to move shortly after surgery has been completed.  If you have an increased risk of developing a DVT your surgeon may opt to treat you with medication to thin the blood for a short time after your surgery to reduce the risk.
  • Nerve damage – as part of the surgery small nerves within the skin are cut which can result in permanent loss of sensation in a patch of skin around the knee.
  • Stiffness – the surgery is designed to stabilize your knee, with the aim being to make it feel the same as your un-injured side.  Rarely patients develop more scar tissue (arthrofibrosis) which can result in a greater level of stiffness than desired.  This is a higher risk if surgery is undertaken too soon after the initial injury.
After Surgery

ACL Rehabilitation

Your rehabilitation programme will be tailored to your individual needs and will progress at the rate that matches your healing and progress.  You will be assessed in the post-operative period by a ward physiotherapist who will instruct you on the early exercises you will need to do.  The most important aspect of rehabilitation is to regain quadriceps (thigh muscle) function and full extension (straightening) of the knee.   During the first few weeks it is beneficial to use a simple compression bandage and regular ice to help reduce the swelling.

The rehabilitation course has been divided into different phases.  The following information is taken from the UK National Ligament Registry which is a good source of further information (

Phase One: Preoperative Preparation and Operative Period

Rehabilitation begins before surgery in the pre-operative phase to ensure that the individual and their knee are ready for the operation.

  • Ensure adequate range of movement, especially normal hyperextension, i.e. so the knee extends to the same as the other leg.
  • Exercises to maintain quadriceps and hamstring muscle strength. Start balance control exercises
  • Advice session in the physio department for familiarisation with post op exercises and hospital stay. 

Phase Two: Initial Post Op Phase

The aim of this phase is to regain the range of joint movement and to allow swelling in the knee to settle. The most important aim is to regain normal and full extension (straightening) of the knee.

Review Goals:

  • Range of movement: full knee extension to 110 flexion
  • Wound healed
  • Minimal swelling in knee and around wound
  • Normal walking pattern
  • Good independent single leg balance control
  • Achieve full passive hyperextension

Phase Three: Proprioception Phase (Sensory Awareness)

The aim of this phase is to work on proprioceptive exercises.  This stage is also important for developing core stability to help you progress to full active function.  By the end of six weeks your knee should feel normal in activities of daily living. 

Review Goals:

  • Full range of movement including normal hyperextension
  • Minimal Swelling in knee
  • Full patella mobility
  • Minimal discomfort

Phase Four: Strength Phase

At six weeks the graft should be solidly fixed into bone so that more vigorous strength training can start. Thigh muscle tone and definition (quadriceps / hamstrings) will hopefully have been maintained during the first post op phase and now the main strength work can begin.  

Progress is monitored and controlled by the recovery of strength and muscle control.  It is important to avoid too rapid progress, as there is a risk of developing overload complications. 

Review Goals:

  • Full range of movement 
  • No swelling
  • Confident feeling of stability

Phase Five: Early Sport Training Phase

Pivoting and cutting movements are introduced at this stage, building up to light sport training. This involves a progressive programme of slow and moderate speed strength training and agility drills. Manual work should be possible within the restraints of the occupation. Exercises for power and agility training are introduced.  

Many sport specific skill training exercises can be introduced at this stage and detail for particular sports is given in the next section as there is some overlap during these phases. The new ligament is still at significant risk of re-injury or of stretching out if progress back to full levels of sport is too fast.

There is no one solution that fits all individuals and great emphasis is given on the care in progressing through this phase back to sport.  Supervision by a Physio, sports coach or trainer is key, as drill and skill acquisition is dependent on individual muscular control patterning in addition to individual relative strength deficits around the hip, knee and ankle.

Review Goals:

  • Full Range of movement
  • Functional and Strength tests: 85% of normal side
  • Return to non contact sports training

Phase Six: Return To Sport Phase

The aim of this phase is to progress sport training and to develop strength and endurance levels to allow return to full sporting activity. This takes time, especially in building up confidence to progress to full contact activities.

Return to contact sport is not recommended until strength and functional outcomes are measured at greater than 85% of the normal knee.   It should be remembered that the time to regain pre-injury level of skill and performance is very variable but can take 3 – 4 months of training and playing.  This confidence can be helped by introducing modified training and specific drills early, often in conjunction with club or team activities.

Progress is best achieved in conjunction with a general fitness programme, as this will have reduced over time since the injury and surgery.   Full contact sport is, in general, best avoided until able to tolerate a full training session with confidence in full fitness and endurance.

Full details of return to sport rehabilitation should be obtained from the surgical and rehabilitation team.

Important: this information given above is only a guideline as is not complete.  For more information or to book an appointment please contact us.