Cartilage repair procedures

What Is An Articular Cartilage Defect?

The surface of the knee joint is lined with a thick white layer of hyaline cartilage, which keeps the joint moving in a smooth, pain-free manner.

Damage to this cartilage lining of the knee can result in pain, instability, and locking within the knee. This is one of the most common reasons why patients seek medical help from knee surgeons.


A cartilage surface defect (chondral flap or osteochondral lesion) is when a particular cartilage area within the knee peels off the surface and the underlying bone is exposed, leading to pain and instability.

Osteoarthritis is when the cartilage, which covers the ends of bones at joints, wears away, and there is bone-on-bone contact.

What Can Be Done To Repair Cartilage Defects?

Some cartilage defects are best treated without surgery, particularly if they are at an early stage and not unstable.

Keyhole surgery, in the form of arthroscopy, is effective in establishing the true extent of the unstable defect and is often better than an MRI scan.

Minor trimming procedures to repair and smooth surface defects can be successfully done through keyhole techniques.

Various cartilage stimulation techniques have developed over the years with varying success rates. These include microfracture procedures which stimulate new fibrocartilage growth on the defect, microfracture plus a procedure to cover the defect (with minute membranes, tissue glue etc.), autologous chondrocyte implantation and matrix-induced autologous implantation procedures (ACI and MACI) which involve growing new cartilage and implanting it on the defect and newer techniques to cover the defects with artificial surfaces (e.g. HemiCAP, Episurf Medical etc.).

Occasionally, joint resurfacing procedures are needed to treat a particularly large or painful surface defect.

Mr Rajaratnam is an expert in treating cartilage surface defects and seeks to balance the need to embrace new techniques (which may be innovative and exciting but relatively unproven) with older proven techniques (which have been extensively studied, are known to be safe, and whose success rates are known).

He feels that cartilage repair is the most exciting pioneering frontier in orthopaedic surgery of the knee.

Every patient needs to be assessed individually and given bespoke advice and treatments for this challenging condition.