Autologous Chondrocyte Implantation (ACI) at Tunbridge Wells Hospital

What is autologous chondrocyte implantation (ACI) surgery?

Autologous Chondrocyte Implantation surgery, also known as ACI surgery, is a well-established but highly specialised treatment that is used to repair defects in the cartilage, which is the flexible, connective tissue found in joints, such as the knee.

Autologous chondrocyte implantation surgery is a two-step surgical procedure. In the first operation, your surgeon will extract some of your own cartilage cells which are then sent to a specialist laboratory. The laboratory expands and grows these, ready to reimplanted to treated the area where your cartilage is damaged. This is considered the ‘gold standard’ treatment for suitable cartilage defects, with a high success rate of approximately 85%¹.

What are the benefits of autologous chondrocyte implantation?

ACI is a powerful and reliable treatment when delivered by a specialist in joint preserving surgery. Other key benefits of this treatment include:

• The ability to generate new, high-quality cartilage that is more durable and more closely resembles the natural joint tissue.
• Effectiveness for larger cartilage defects, where most alternative techniques area unsuitable .
• Helping to preserve the health and condition of the joint longer-term, which could delay the onset of osteoarthritis and more significant surgeries, such as joint replacement.

What else is autologous chondrocyte implantation surgery known as?

You may also hear autologous chondrocyte implantation surgery known as ACI knee cartilage therapy, cartilage cell transplantation or a cartilage patch. It is also sometimes confused with matrix-induced autologous chondrocyte implantation or MACI.

What is the difference between autologous chondrocyte implantation (ACI) and matrix-induced autologous chondrocyte implantation (MACI)?

Both ACI and MACI involve using your own cells to repair damaged cartilage in a joint. However, the difference is in the technique, with MACI placing your harvested cartilage cells onto a scaffold (also known as a matrix) before they are implanted. In contrast, ACI sees individual cells implanted directly into the joint, and then covered with a patch to keep them in position.

What conditions can autologous chondrocyte implantation (ACI) treat?

Autologous chondrocyte implantation is typically recommended as a treatment for large focal cartilage defects, which are usually caused by accident or injury. These are normally single, full-thickness defects over 2cm² as these are not usually suitable for alternative procedures.

How do I know if I need autologous chondrocyte implantation (ACI) surgery?

Your orthopaedic consultant will be able to advise you if you may need autologous chondrocyte implantation.

Who is suitable for an autologous chondrocyte implantation?

ACI surgery is generally recommended for healthy people with large areas of full-thickness cartilage damage, usually 2cm2 or more. Good candidates are generally between the ages of 13 and 55, with little to no signs of osteoarthritis or previous joint injury and should be able to commit to a fairly intensive six-month rehabilitation programme.

Who is not suitable for autologous chondrocyte implantation?

You may not be a good candidate for autologous chondrocyte implantation if you have:

• A high BMI, as studies suggest, is associated with significantly lower success rates³.
• Moderate to severe osteoarthritis
• Been diagnosed with rheumatoid arthritis
• An area of damage less than 2cm2
• Previously had a failed cartilage surgery
• An unstable joint (untreated).
• Malignment of the joint (untreated).

You may also be unsuitable if you aren’t able to commit to the rigorous rehabilitation programme.

What happens during autologous chondrocyte implantation (ACI) surgery

How can I prepare for autologous chondrocyte implantation (ACI)?

Before you can have autologous chondrocyte implantation surgery, you’ll need to have a pre-operative assessment to determine if you’re a suitable candidate for the procedure.

Whilst ACI may be the recommended treatment for your cartilage damage, your surgeon should also assess your knee alignment and knee stability. If you have a significant ‘knock-kneed’ or ‘bow-legged’ alignment, then an osteotomy may be needed to offload and protect the new cartilage. If you have a ligament injury, such as a ACL injury , then it is important you knee is stabilised, often with a ligament reconstruction, before proceeding with ACI.

Pre-operative assessment for autologous chondrocyte implantation

Your pre-operative assessment will usually be carried out by a member of our nursing team, and usually involves a review of your medical history, and routine observations such as your height, weight and blood pressure. If your nurse thinks it is necessary, you’ll also be given pre-operative tests such as blood tests, urine tests and MRSA swabs.

Your nurse will give you specific guidance on how to prepare for the day itself, including if and when you should stop eating or drinking, if you need to stop or pause any usual medications, and any other requirements – for example, not wearing jewellery or false nails.

What should I expect during an autologous chondrocyte implantation (ACI)?

ACI surgery is a two-stage procedure, with both parts typically being performed under general anaesthetic, meaning that you’ll be asleep for the duration.

Stage one
Stage one is a minimally invasive surgery during which small incisions are placed into the joint to remove a small section of healthy cartilage from a non-load-bearing area of the joint. It typically takes around 30 minutes or less.

Once the cells are removed, they are taken to a lab to be cultured (multiplied). This usually takes 8 weeks. Once the cells are ready, you’ll be scheduled in to have the second stage of your procedure.

Stage two
Open surgery is needed to implant the new cells into the joint. This means a larger incision made into the skin, which is opened up to enable the transplant. A patch is usually sewn over the damaged cartilage, so that the new cells can be injected underneath.

Once complete, the incision will be closed and the wound dressed. The entire procedure can usually be completed in under 90 minutes.

How long does it take to recover after autologous chondrocyte implantation (ACI?)

Before you undergo autologous chondrocyte implantation, your consultant will explain that the procedure has a significant recovery period and you will need to commit to a rehabilitation programme that takes anywhere from six to 12 months.

For the first two weeks, the focus of your recovery will be on reducing swelling in the joint and beginning to develop range of motion using very specific, controlled movements, often performed by a machine.

Weeks 2 to 8, you may need to wear a knee brace and use crutches to ensure limited weight bearing on the joint, while continuing to follow all physiotherapy exercises and other elements of your rehabilitation programme.

Most people can start to bear weight on their knee joint around three months after surgery, but you’ll still need to stick closely to your rehabilitation programme to achieve full range of movement and ensure the best possible outcome from your treatment.

How soon can I go home after ACI surgery?

Some people may be able to go home the same day as their procedure, while others may be recommended to stay in the hospital for a night or two, to support the start of their recovery. Your consultant will be able to advise you on how long you can expect to stay.

How soon can I walk after autologous chondrocyte implantation?

Many people can begin to walk with crutches a few days after their surgery, but you can expect to continue to need them for six weeks or more, depending on the rate of your recovery.

How soon can I return to work?

This depends on the type of work that you do. If you have a desk job, you may be able to return to work a few weeks after surgery, provided you are able to manage the demands of your job and rehabilitation requirements. However, if you have a more manual job, it could be several months before you can go back to work. Always follow the recommendation of your consultant.

How soon can I drive?

Most people can start driving again around six weeks after surgery, but always follow the advice given to you by your medical team. br>

How soon can I exercise or play sports after ACI surgery?

Rehabilitation after ACI surgery is a gradual process, and while you may be able to take part in light physical activity a few months after your procedure, it usually takes up to 18 months to get back to high-intensity exercise.

Will I need physiotherapy after autologous chondrocyte implantation?

Yes, expect to need long-term physiotherapy for up to 18 months following your autologous chondrocyte implantation procedure. This is usually more intensive to begin with and then eases into routine appointments. You’ll need to complete your physical therapy exercises at home, as well as during your appointments.

How much does autologous chondrocyte implantation cost at Nuffield Health?

For pricing information, please contact your local hospital. The hospital or your healthcare team will give you a fixed all-inclusive price for the treatment following your initial consultation.

Sources
1 https://www.engage.england.nhs.uk/consultation/copy-of-clinical-commissioning-wave5/user_uploads/d10...
2 https://pmc.ncbi.nlm.nih.gov/articles/PMC2795849/#:~:text=Our%20data%20demonstrate%20that%20autologo...
3 https://www.ncbi.nlm.nih.gov/books/NBK424062/
4 https://pubmed.ncbi.nlm.nih.gov/40169165/
5 https://pubmed.ncbi.nlm.nih.gov/20181804/#:~:text=Conclusion:%20Autologous%20chondrocyte%20implantat....