BMAC (bone marrow aspirate concentrate) injections

PRP and BMAC are both treatments that use your body’s own healing ability, but they are used at different stages.

PRP is usually the first step and works best for early to moderate joint problems, tendon issues, or soft‑tissue injuries. BMAC is considered when joint damage is more advanced, when scans show problems in the bone beneath the cartilage, or when PRP has helped but not enough or not for long.

BMAC works at a deeper level than PRP. In some cases, the two treatments may be used together or in sequence, depending on what the joint needs.

BMAC is most suitable for:

• people with moderate arthritis of the knee, hip, shoulder, or ankle who still have some healthy cartilage on scans
• patients whose MRI shows changes or inflammation in the bone beneath the joint surface, which is a common source of pain
• people with long‑standing tendon problems that haven’t improved with physiotherapy and PRP
• patients whose symptoms persist despite standard injections, but who are not yet ready for surgery

BMAC is less helpful for people with very advanced arthritis where the cartilage is almost completely worn away.

A full assessment, including a review of your MRI, is essential. Your consultant will advise whether your specific joint problem is one that BMAC is likely to help.

A BMAC procedure is carried out in theatre. You can have the procedure under local anaesthetic, light sedation, or occasionally a short general anaesthetic, depending on what is most appropriate and comfortable for you.

First, a small amount of bone marrow is taken from the back of the hip bone. This is done using a specialist needle. The bone marrow is then processed straight away to concentrate the parts that help healing. This step usually takes about 15 to 20 minutes.

Once prepared, the BMAC is injected into the area being treated using ultrasound or X‑ray guidance. If pain is coming from both the joint and the bone underneath it, the treatment may be injected into the bone itself, as well as into the joint.

In some cases, BMAC is combined with PRP on the same day to enhance the healing response.

Because BMAC uses your own cells, there is no risk of rejection or allergy.

The most common side effects are temporary and include:

• soreness at the hip (pelvis) where the bone marrow is taken, usually lasting two to five days
• a temporary increase in joint pain or swelling for the first one to two weeks as the treatment begins to work

These effects usually settle on their own without treatment.

As with any injection, there is a small risk of infection, but this is rare.

Some patients experience a stronger pain flare in the first week, which usually settles without intervention.

Responses to BMAC can vary. Many patients improve, but not everyone achieves the same degree of improvement, and some may not respond significantly. Your consultant will discuss what level of improvement is realistic for your specific condition before proceeding.

Most patients will return home the same day as the procedure.

It’s normal to experience an increase in joint symptoms for one to two weeks. This is part of the body’s healing response and usually settles on its own.

If BMAC is going to help, improvement is typically noticed between six and 12 weeks, with the greatest benefits apparent at three to six months. How much improvement you experience, and how long it lasts, depends on factors such as the type and severity of your joint problem and your overall health.

You’ll usually have a follow‑up appointment at around six to 12 weeks. This allows your consultant to review your progress and decide whether any further treatment is needed or whether the plan should be adjusted.