Q & A

ABICUS FAQsDSC9570(1)web

What is the purpose of the study?

We are comparing two procedures for the treatment of cartilage defects in the knee and hip to see which provides the better pain and movement outcomes.

Cartilage defects are most commonly caused by injury, and the first procedure being compared is microfracture, where holes are drilled into the bone of the injured joints, to form a ‘skin’ of scar tissue over the defect.

The second procedure is the new ABICUS technique, which involves drilling of the cartilage defect before injecting a mixture of your own bone marrow cells in a matrix, or ‘glue’. The trial aims to assess whether ‘new’ cartilage fills the defect instead of scar tissue and whether or not this leads to a better outcome with less chance of developing arthritis in the knee.

Which treatment will I get?

If you agree to take part you will be allocated to either the microfracture group or the ABICUS group. This allocation process is performed randomly by a computer, so there is no bias involved and the test is balanced. There will be an equal chance of receiving either procedure.

Do I have to take part?

No. It is entirely up to you. If you would like to take part you will be asked to sign a consent form to ensure you understand what it is all about and to state that you are happy to take part. If at any time you wish to withdraw from the study you are entirely free to do so and your treatment will not be affected in any way. Patient confidentiality will be maintained at all times.

Will my GP be notified?

Yes, a letter will be sent to your GP notifying of your participation in the study, with details of the study purpose and design (with your consent). You may discuss participation in the study with your GP.

What will happen to me if I take part and I am placed in one of the groups?

If you agree to participate in the study you will be asked to fill out a consent form. Participation in this study involves a variety of assessments. This includes a clinical assessment and filling in some questionnaires that will assess you with regards to level of pain and activities of daily living. These questionnaires should take no longer than ten minutes to complete.

After the surgical procedure you will then undergo post-operative reviews by your surgeon at six weeks, three months, six months, and one year post-operatively where you will be examined and asked to complete the same questionnaires as you did prior to your operation. At one year you will also undergo a repeat MRI examination of your knee or hip joint.

What is microfracture?

Microfracture is a conventional treatment for cartilage defects in the knee and hip. Following anaesthesia, arthroscopic (keyhole) surgery of either the knee or hip is performed. The area of cartilage defect is prepared with an arthroscopic shaver and the edges of the defect are defined with this instrument. Multiple defects in the sub-chondral bone (bone just beneath the joint surface) are then made with a chondral pick. The pick is lightly hammered into the sub-chondral bone and inserted approximately 5mm into the bone. After each hole is made, an arthroscopic shaver is inserted to remove any loose debris and tidy up the bone edges. The procedure takes approximately 30 minutes.

What is the ABICUS procedure?

Following anaesthesia, a sample of your own bone marrow is taken from the pelvis. This is performed by making an incision (cut) less than 5mm in length on the iliac crest (the part of the pelvis felt at the waist) on the same side as the planned knee or hip surgery. A needle is placed into the bone (approximately 2cm into the bone) and a sample of bone marrow is drawn up though the needle (bone marrow aspirate). A dressing is then placed over the wound.

This sample is then placed in a centrifuge and spun down in the operating theatre to give a concentrated amount of your own stem cells. It takes approximately 5 minutes to take the bone marrow cells and a further 5 minutes to spin the cells down (although we carry on with the operation whilst the cells are being spun down).

Arthroscopic (keyhole) surgery of the knee or hip is then performed, and the cartilage defect is debrided with an arthroscopic shaver. The defect is prepared in a similar way to microfracture, but not as many holes are made in the bone. Following preparation a mixture of the stem cells and a matrix of fibrin glue is placed over the cartilage defect and allowed to set (this takes 2 minutes). The total operating time is approximately 30 minutes. In microfracture, more time is spent between the creation and tidying up around each hole made as there are more holes made in the sub-chondral bone and therefore more debris is created, hence both procedures are roughly comparable in surgical time.

The next part of the study involves the surgical procedure itself. You may either undergo the microfracture technique, or the ABICUS procedure depending on which group you are allocated to. If you undergo the ABICUS procedure, the only additional noticeable feature will be a wound dressing over the area where bone marrow cells are taken (from the pelvis using a needle). The operating time and recovery will be the same regardless of procedure.

What are the possible disadvantages and risks of taking part?

The risks of undergoing surgery are the same in both groups and are related to any keyhole procedure in the knee or hip. These are infection, and venous thrombosis (clots) in the leg, and failure to relieve symptoms. The other main risk or discomfort following microfracture is pain. This can be longer lasting pain following the procedure that may persist for up to four weeks, although usually pain does not last more than two weeks.

The ABICUS procedure in the knee or hip is not associated with any additional pain or disability compared to microfracture. There are no known other risks.

There is a very small risk of bleeding (less than 2%), and infection (less than 1%) from the site on the pelvis where the bone marrow cells are taken from. There is also a small risk of pain (less than 2%) from the site that usually resolves within six weeks of surgery.

What happens when the research study ends?

You will be in the study for 12 months. If you are still having problems after this time, your surgeon will continue your care.

What happens if something goes wrong?

In the event that something goes wrong and you are harmed and this is due to someone’s negligence, then you may have grounds for a legal action for compensation against University Hospital Southampton NHS Trust, but you may have to pay legal costs. The normal NHS complaints mechanisms will still be available to you.

Will my taking part in this study be kept confidential?

All information about you is kept strictly confidential. No information has your personal details so you cannot be identified at any time.

What will happen to the results of this study?

This study will last two years, with a planned end date in 2015. We will publish the results in medical journals (you will not be identified) and conferences. If you would like a copy of the results, please ask a member of the team.

What will happen if I decide not to participate in the study?

Your care will not be affected and you may discuss your further treatment with your surgeon.

Who has reviewed this study?

This study has been reviewed and approved by a research ethics committee: South Central – Hampshire B.

Should you require any further information please contact Mr Gorav Datta (023 8120 5292), or email gorav.datta@uhs.nhs.uk.

For independent advice contact patient support services on 023 8120 6325.