Anterior Cruciate Ligament (ACL): Injury, Treatment Repair & Reconstruction Surgery Options in Bristol & Bath

An ACL injury, tear, or rupture is one of the most common causes of knee instability after a twisting or pivoting event. The ACL (anterior cruciate ligament) is a key stabiliser inside the knee that helps control forward movement of the shin bone and rotational stability. When the ACL is torn, the knee can feel unreliable–especially during sport, turning, deceleration, or uneven ground.

Mr Simon Abram, Consultant Knee Surgeon, is a specialist in the assessment and treatment for ACL injuries in Bath and Bristol. Treatment may be non-surgical (rehabilitation-led) or surgical (ACL reconstruction), depending on your stability symptoms, activity goals, knee anatomy, and associated injuries such as meniscus or cartilage damage.

What does the ACL do?

The ACL sits in the centre of the knee. It helps:

Control forward movement of the tibia (shin bone) under the femur (thigh bone)
Control rotation during pivoting, twisting and landing
Provide confidence and stability in cutting and deceleration movements

The ACL works together with the meniscus, cartilage, and other ligaments. This is why a “simple ACL tear” is sometimes actually a more complex injury pattern.

How ACL injuries happen

ACL tears often occur during a sudden twist, pivot, awkward landing, or contact injury. Common scenarios include:

Football, rugby, netball, skiing, basketball and racquet sports
A sudden change of direction or deceleration
Landing from a jump with the knee collapsing inward
A direct collision causing the knee to rotate or hyperextend

Symptoms of an ACL tear

A popping sensation at the time of injury (not always)
Rapid swelling within a few hours (common, but not universal)
Difficulty continuing sport immediately after injury
Recurrent giving way, shifting, or loss of confidence with pivoting
Swelling after activity, especially if the knee is unstable

Urgent red flags

Seek urgent assessment if you have a locked knee (cannot fully straighten), severe swelling, suspected knee dislocation, numbness/weakness in the foot, or a cold/pale foot after injury.

Assessment and diagnosis (Bath & Bristol)

Accurate diagnosis matters because ACL tears often occur with associated injuries that can change treatment (meniscus tears, meniscal root tears, cartilage injury, bone bruising, and occasionally other ligament injuries).

Assessment usually includes:

History: mechanism, swelling timing, instability episodes, sport/work demands
Examination: ACL stability tests and assessment of the whole knee
Imaging:
- MRI scan to confirm the ACL tear and identify meniscus/cartilage injury
- X-rays when needed to assess alignment or where this concern about a fracture

The goal is to confirm the diagnosis and create a plan tailored to your goals: return to sport, stable day-to-day function, or protecting long-term knee health.

Treatment options: rehab vs ACL reconstruction

Non-surgical treatment (rehabilitation-led)

Some people can manage without ACL reconstruction, particularly if they do not take part in pivoting/contact sport and the knee does not give way. Non-surgical management typically includes:

Swelling control and restoring full range of motion
Progressive strengthening (quadriceps, hamstrings, glutes and trunk control)
Neuromuscular training (landing, deceleration and balance control)
Criteria-based return to activity

Rehabilitation is also essential even if surgery is planned, because a strong, calm knee before surgery improves early recovery.

When ACL reconstruction is considered

ACL reconstruction is more likely to be recommended when:

You have recurrent giving way or lack of trust in the knee
You want to return to pivoting or contact sport
Instability is limiting your work, lifestyle, or confidence
There are important associated injuries (for example certain meniscus tears) where stability supports healing

The decision is shared and personalised. The aim is a stable knee that you can trust.

What is ACL reconstruction?

ACL reconstruction replaces the torn ligament with a graft. The graft acts as a scaffold that becomes incorporated and functions like a new ACL. The operation is usually performed using keyhole (arthroscopic) surgery, often with small additional incisions to harvest and secure the graft.

During surgery, associated problems may also be treated–such as meniscal repair, treatment of cartilage injury, or additional stabilisation procedures for rotational control in selected cases.

ACL graft choices (a key part of personalised planning)

There is no single “best” ACL graft for everyone. Graft choice depends on your sport, anatomy, previous surgery, occupation, risk profile, and preference. The aim is a graft that matches your knee demands while balancing donor-site symptoms and recovery.

1) Hamstring autograft

Hamstring ACL reconstruction uses tendon from the inner side of the knee. A modern approach often uses a quadrupled semitendinosus graft to create a strong multi-strand construct. In many cases this can be achieved using one hamstring tendon (semitendinosus), preserving the gracilis. The gracilis is used only in selected cases if additional graft diameter is needed.

Considerations: temporary hamstring weakness and discomfort can occur early on; rehabilitation targets hamstring recovery and overall movement control.

2) BTB (Bone-Patellar Tendon-Bone) autograft

BTB uses the middle part of the patellar tendon with small bone blocks at each end. It provides very solid fixation and is often considered in high-demand pivoting athletes or certain revision scenarios.

Considerations: some patients find it difficult to kneel on the scar at the front of the knee.

3) Quadriceps tendon autograft

Quadriceps tendon grafts use tendon from the front of the thigh just above the kneecap. It can be a strong, versatile option for primary and revision ACL reconstruction and is also useful when previous graft harvest limits other options.

Considerations: early quadriceps weakness can occur, so rehabilitation focuses on safe quadriceps strength and control.

4) Rectus femoris option (selected cases)

Rectus femoris is part of the quadriceps mechanism. In selected complex cases, a rectus femoris-based graft option may be considered, particularly if previous surgery limits graft availability or where a specific graft strategy is required.

Key point: this is used selectively and is planned around your anatomy, sport demands, and recovery priorities.

5) Allograft (donor graft) option

An allograft uses sterilised donor tendon rather than your own tissue. This may be considered in very selected circumstances, such as complex multiligament reconstruction, limited autograft options, particular revision strategies, or some for returning to certain non-pivoting sports.

Considerations: allograft typically has a higher rate of re-rupture / failure than the other grant options. Careful patient selection and consent is important. The pros/cons are discussed carefully as part of shared decision-making.

Contralateral grafts (using the other knee)

In some cases, a graft from the other (contralateral) knee may be the best option–particularly if previous graft harvest limits choices on the injured side, or if a specific graft is preferred for your sport and stability goals. This is discussed carefully because it can cause temporary donor-site symptoms in the other knee during early recovery.

Do I need extra stabilisation (LET / ALL) with my ACL reconstruction?

Some patients have a higher risk of persistent rotational instability or re-injury. In selected cases, an additional procedure such as lateral extra-articular tenodesis (LET) or ALL reconstruction may be recommended to improve rotational control, especially in high-risk pivoting athletes or revision settings.

This is decided based on your examination (including pivot shift), sport demands, anatomy, and overall risk profile.

Meniscus and cartilage: why they matter in ACL injuries

Meniscus tears and cartilage injury are common with ACL tears. Preserving the meniscus and protecting cartilage are important for long-term knee health.

Meniscal repair may be performed at the same time as ACL reconstruction when a tear is repairable.
Meniscal root tears require specialist assessment and may need root repair in suitable cases.
Cartilage injury can range from minor wear to focal defects and may influence symptoms, recovery, and treatment planning.

Rehabilitation after ACL reconstruction (phases and milestones)

Rehabilitation is essential for a good outcome. The safest recovery is usually criteria-based–you progress when your knee is ready, not just when the calendar says so. If you have additional procedures (meniscal repair, cartilage treatment, LET/ALL, or osteotomy), your early phases may be modified to protect healing tissues.

Typical return-to-sport guidance: many pivoting athletes plan return to full sport at around 9–12 months, with individual variation. Some people return earlier to non-pivoting activity, but pivoting/contact sport usually demands longer rehabilitation and testing.

Risks and considerations

ACL reconstruction is generally very successful, but all surgery carries risks. Potential issues include:

Infection, blood clots, wound problems
Stiffness or prolonged swelling
Persistent instability or graft failure (particularly if risk factors are not addressed)
Ongoing pain or donor-site symptoms
Meniscus or cartilage problems that continue to influence symptoms

Your consultation includes a personalised discussion of risks, expected outcomes, and how these risks are reduced through planning and rehabilitation.

Frequently asked questions

Do I always need surgery for an ACL tear?

No. Some people do well with rehabilitation alone, especially if the knee is stable in day-to-day life and pivoting sport is not a goal. Surgery is more likely when instability persists or sport demands are high.

When is the best time to have ACL reconstruction?

Timing is individual. Many patients do best when the knee is “calm” before surgery: minimal swelling, good movement, and good quadriceps control. This reduces the risk of stiffness and improves early recovery. Urgent surgery may be considered in selected cases (for example, certain locked bucket-handle meniscus tears).

Will I need physiotherapy after ACL surgery?

Yes. Physiotherapy is essential and is the main driver of recovery. The operation provides the stabilising graft; rehabilitation provides strength, control, and safe return to sport.

How long will I need crutches?

Most patients use crutches for comfort and safety in the first 4-6 weeks. The goal is a normal walking pattern. The duration varies depending on pain, swelling, quadriceps control, and any additional procedures such as meniscal repair.

When can I drive?

Driving depends on which leg was operated on, your confidence, pain control, and ability to perform an emergency stop safely. As a guide, most people should avoid driving for 5–6 weeks after ACL surgery and should no longer be reliant on crutches. You must be fully and safely in control of the car and able to make an unrestricted emergency stop. Individual advice is given based on any associated injuries, specific surgery, and progress.

When can I return to work?

This depends on your role. Desk-based work may be possible within 4-6 weeks if swelling is controlled and you can elevate the leg. Physical jobs often require longer (typically a minimum of 3 months) and may need staged duties.

When can I start running?

Running is introduced when you have adequate strength, good single-leg control, minimal swelling response, and the right movement mechanics. The timing varies between individuals and is later if additional procedures were performed.

When can I return to football/rugby/skiing?

Pivoting sports typically require the longest rehab. Many athletes plan return at around 9–12 months, based on objective testing, movement quality under fatigue, and confidence. Returning too early can increase re-injury risk.

What if my knee still swells after rehab sessions?

Temporary swelling is normal as you increase your activity level but more prolonged swelling is a sign the knee is not tolerating the current load. Your rehabilitation plan will be adjusted in intensity as you make progress, improve your recovery, and gradually build functional capacity.

Which ACL graft is best?

The best graft is the one that best matches your knee, your sport, and your risk profile. Options include hamstring, BTB, quadriceps tendon, and rectus femoris grafts. Allograft in rare specific circumstances. In some cases, a graft from your other leg may be discussed as a good option.

What if I have already had ACL surgery before?

If you have had previous ACL reconstruction and your knee is unstable again, revision ACL reconstruction may be needed. Revision planning is more complex and often involves imaging-led tunnel and graft strategy planning, plus addressing rotational or alignment factors where relevant.