ACL Reconstruction

Restoring knee stability with advanced, evidence-based techniques tailored to you.

ACL Reconstruction – Key Points

• The ACL stabilises the knee, especially during twisting and pivoting
• A tear can cause instability (“giving way”) and further damage
• Treatment includes physiotherapy or surgery depending on your goals
• Surgery is a keyhole procedure using a tendon graft
• Recovery takes 9–12 months with structured rehabilitation
• The aim is a stable knee and safe return to activity

What is the ACL and why is it important?

The anterior cruciate ligament (ACL) is one of the main stabilising ligaments in the knee. It prevents the shin bone from moving forwards and controls rotation.

When the ACL is torn, the knee can feel unstable or “give way”, particularly during twisting or pivoting movements. This is common in sport but can also affect daily activities. Straight-line activities such as walking are often better tolerated.

ACL injuries are relatively common and often occur during sport, although they can happen in other situations.

Assessment and associated injuries

Following injury, careful assessment is required. This includes clinical examination and imaging, most commonly with X-rays and MRI scans, to confirm the diagnosis and identify any associated damage.

Meniscal tears are very common alongside ACL injuries:

• The lateral meniscus is often injured at the time of the ACL tear, sometimes involving the root
• The medial meniscus is more likely to be damaged later if instability persists

The meniscus acts as a shock absorber in the knee, and untreated tears can increase the risk of arthritis. Where possible, meniscal tears are repaired at the time of surgery.

Do I need surgery?

Rehabilitation (non-surgical treatment)

Physiotherapy focuses on strengthening the muscles around the knee and improving control.

Benefits

• Avoids surgery
• Can improve stability in some patients

Limitations

• Instability may persist, particularly during pivoting activities
• You may need to modify activity levels
• There is a risk of further injury, particularly to the meniscus

ACL reconstruction surgery

ACL reconstruction is a keyhole (arthroscopic) operation to replace the torn ligament with a tendon graft, usually taken from your own body. A recent large trial showed that overall patients that had ACL reconstruction did better than those that had physiotherapy alone.

Benefits

• Restores knee stability
• Reduces the risk of further damage to the knee
• Allows return to sport and higher-level activity

What does the operation involve?

The procedure usually takes 1–2 hours and is performed as a day case.

• Small incisions are made around the knee (keyhole surgery)
• A graft is taken (hamstring, patellar tendon, or quadriceps tendon)
• Tunnels are created in the thigh bone (femur) and shin bone (tibia)
• The graft is positioned and fixed in place using screws or buttons

Graft choice – tailoring surgery to you

There is no single “best” graft—this depends on your age, activity level, and individual risk factors.

• Patellar tendon (BTB)
  Strong graft with excellent long-term results, often used in younger or higher-risk patients. It can occasionally cause pain at the front of the knee.
• Hamstring tendon
  Most commonly used in the UK. Good overall results and well tolerated. Well suited to medium and low risk patients.
• Quadriceps tendon
  A thicker, strong graft with increasing popularity. Often associated with less kneeling pain, but can cause weakness in the quadriceps.
• Allograft (donor tissue)
  Avoids taking tissue from your own body but may take longer to incorporate and is used selectively.

Additional procedures

Lateral extra-articular tenodesis

Some patients benefit from an additional procedure called a lateral extra-articular tenodesis (LET). This reinforces the outside of the knee and has been shown to significantly reduce the risk of graft failure in higher-risk individuals.

Meniscal surgery

Meniscal tears are very common in association with ACL injuries. The meniscus is an important shock absorber in the knee, helping to distribute load and protect the joint. Preserving the meniscus is crucial for long-term knee health.

Where possible, meniscal repair is always preferred over removal, as this helps reduce the risk of early arthritis and maintains normal knee function.

Common types of meniscal tears seen with ACL injuries include:

• Ramp lesions – tears at the back of the medial meniscus
• Root tears – where the meniscus detaches from its attachment to bone
• Bucket handle tears (BHT) – larger tears that can cause locking of the knee

These injuries can sometimes be difficult to detect and require careful assessment at the time of surgery. Mr Smith has particular expertise in identifying and repairing complex meniscal tears, including root and ramp lesions, to optimise long-term outcomes.

If a tear is not repairable, the damaged portion may need to be trimmed (partial meniscectomy), although this is avoided where possible.

Synthetic augmentation

Synthetic augmentation is a newer technique used alongside ACL reconstruction, where a synthetic tape is added to reinforce the graft. The aim is to provide additional stability in the early stages of healing and potentially reduce the risk of re-injury.

Early evidence is promising. A systematic review conducted by Mr Smith has shown that synthetic augmentation may increase rates of return to sport and reduce re-tear rates. However, high-quality evidence is still needed to determine whether these findings are genuine effects of the augmentation.

Mr Smith is Chief Investigator of a £1.9 million NIHR-funded randomised controlled trial investigating synthetic augmentation in ACL reconstruction, helping to define its role in modern knee surgery.

Risks of ACL reconstruction

ACL reconstruction is generally very successful, but potential risks include:

• Infection or blood clots
• Pain and swelling
• Graft re-tear (risk varies depending on age and activity level)
• Stiffness or reduced movement
• Ongoing instability
• Symptoms from the graft harvest site (e.g. kneeling pain or muscle weakness)
• Rare injury to nerves or blood vessels

These risks will be discussed in detail and tailored to your individual situation.

Preparing for surgery

Surgery is usually performed once:

• Swelling has settled
• Movement has returned
• Strength has improved

This “prehabilitation” phase is important and improves outcomes after surgery.

You will usually have the procedure as a day case. You will need someone to take you home and stay with you overnight.

Recovery and rehabilitation

Recovery typically takes 9–12 months.

Rehabilitation progresses through stages:

• Early recovery and movement
• Strength and muscle control
• Balance and proprioception
• Agility and sport-specific training
• Return to sport

Most patients return to sport at around 9–12 months, depending on progress and individual risk.

ACL prevention programmes

There have been several sport specific ACL prevention programmes developed that have been shown to reduce your risk of ACL rupture. Any patient with an ACL reconstruction can apply this to this reconstructed side as well as their other side (which is at an increased risk compared to the general population). It is encouraged that you incorporate these prevention exercises into your rehabilitation, and also continue them into the future.

Football –         FIFA 11+ https://youtu.be/X5YyunLZzBc

PEP  program https://youtu.be/7Lag8uNU6AQ

Rugby –              NSW rugby ‘preparation to perform’ program

https://nsw.rugby/participate/programs/prep-2-perform

Tennis –             Lateral step lunges, forward and backwards running drills

Skiing –              Lateral box stepping and jumping, zigzag hopping

Netball –           Netball Australia’s ‘knee program’ https://knee.netball.com.au

Why choose Mr Smith?

Mr Smith is a leading UK knee surgeon with extensive experience in ACL reconstruction, including complex and high-risk cases. His practice is supported by a leading research programme, including NIHR-funded clinical trials and pioneering work investigating factors such as tibial slope and ACL failure.

You will receive a personalised treatment plan based on your goals, anatomy, and risk profile—using the most advanced, evidence-based techniques available.