Performed by – Khalid Al-Hourani, Alastair Davidson, Azal Jalgaonkar, Reza Mansouri, Zuhair Nawaz, James Singleton

Defects in the articular cartilage covering the bones of the knee joint can be caused by traumatic injuries as well as minor twisting injuries. They will result in pain and swelling as well as sometimes clicking and locking of the knee. These are usually first treated with knee arthroscopy (keyhole surgery) and a smoothing of the edges, as well as a ‘microfracture’ to full thickness defects. This involves small picks used to make holes through the surface of the bone to release the bone marrow. This contains stem cells to promote healing of the cartilage that would otherwise heal poorly or not at all.

Such defects left untreated usually continue to cause pain and problems and will develop into established arthritis. Further technical advances have now made it possible to fill the defects with scaffolds to enhance the result of the microfracture technique, which can be further enhanced by bone marrow aspiration cells, gained through another small stab incision, to create a higher concentration of stem cells in the affected area. It is important to realise that this technique is for isolated defects surrounded by healthy cartilage, much as one repairs the divots on a golf course by patching the hole, rather than for established arthritis. Other techniques also exist, utilising a combination of a patient’s own cartilage, which is morcellised and binding agents from a patient’s blood. Recovery from this surgery can take up to a year, but has the potential to restore a patient’s joint surface back to normal.