Chondral Resurfacing

Joint surface (chondral) injuries are difficult to treat, as articular cartilage does not re-generate and they are often part and parcel of a degenerative process.

A number of treatment are available that can give good benefit but unfortunately despite this often patients will have some ongoing symptoms.

Younger patients with acute traumatic injuries tend to do better than older patients with spontaneous onset of symptoms.

Diagnosis

The diagnosis of a chondral injury in the knee joint is based on the history of an injury and subsequent persisting symptoms of pain or discomfort. Often their are associated catching sensations, sharp pains and swelling.

With bigger injuries then a fragment of bone is often fractured  (osteo-chondral fragment) and might present with more severe pain and swelling due to bleeding into the knee.  This sometimes occurs during a patella dislocation.

X-rays will demonstrate an osteo-chondral fragment but not most chondral injuries as cartilage does not contain calcium and is not visible on X-rays.
An MRI scan will show up most large chondral injuries, but can miss smaller ones.

Arthroscopic surgery can sometimes be the only way they can be diagnosed and can allow treatment at the same time.

Arthroscopy

Arthroscopic surgery if often necessary to diagnose and treat these problems.

Often removal of loose and unstable areas of cartilage will relieve mechanical symptoms including catching and sharp pains.  Often this treatment is all that is necessary.

Unfortunately many patients will have ongoing symptoms particularly if the cartilage lesion is full thickness exposing the underlying bone.  In this case surgery to re-surface the joint including microfracture or other re-surfacing techniques might help.

Microfracture

Arthroscopic view of a micro-fracture chondroplasty
Arthroscopic view of a micro-fracture chondroplast

Microfracture chondroplasty is an arthroscopic surgical technique where  some small holes are made in the bone where the articular cartilage has broken off with  a sharp pick.

The aim of this is to allow the bone to bleed and release bone marrow cells that with the right post-operative management this will stimulate a layer of repair cartilage (fibro-cartilage) to form.

 

The repair cartilage that forms is not as good as original articular cartilage but it is a technique that works very well for the right patients.

Micro-fracture is a very straightforward technique, and can be performed during a routine arthroscopy.

The biggest downside to micro-fracture is the post-operatibve rehabilitation, as depending on the size and location of the micro-fracture crutches might be needed for up to six weeks.

The precise post-operatrive protocol is varied depending on the individual circumstances of the patient.

Autologous Chondrocyte Impltnation

This is a technique that can be used to restore articular cartilage. The technique involves harvesting a small piece of cartilage from the injured knee via arthroscopic surgery.  This tissue is then used to grow cartilage cells in a laboratory before the they are re-implanted  into the knee with an open operation 6-8 weeks later.

 

Diagrammatic representation of autologous chondrocyte transplantation
Diagrammatic representation of autologous chondrocyte transplantation

 

The technique is well established, safe and for the right patients can often offer relief of symptoms in patients who have failed to improve with microfracture chondroplasty.