What is knee microfracture?
Knee microfracture is a surgical option used for treating knees with damaged cartilage. When an individual presents with a small area of damaged cartilage (instead of widespread knee arthritis), microfracture may be a viable treatment option, providing the patients with good and long-term results. The operation is performed in an attempt to stimulate the growth of new cartilaginous tissue in the damaged area.
Every microfracture involves the creation of small holes in the bone where the cartilage defect lays. The surface layer of the bone, known as the subchondral bone, is hard and lacks blood flow. Due to the lack of blood flow, the cartilage defects can't heal by themselves. By penetrating this hard layer and creating small holes, the microfracture allows the blood that is present in the deeper bone areas to access the surface layer, giving a chance for the defect to heal.
Is knee microfracture surgery for everyone?
Microfracture is not for all patients. A good candidate should:
- Have a limited area of cartilage damage
- Wants to stay relatively fit after the operation
- Not be overweight
- Be willing to follow an intensive rehab, and make other sacrifices, for instance quit smoking and other bad habits
- Be 45 years old or younger
Patients who are inactive, have widespread arthritis or are not willing to participate in a demanding and lengthy rehabilitation are usually discouraged from having this kind of operation.
Is microfracture effective?
Microfracture has a high success ration when performed in patients that fit the aforementioned "good candidate" criteria. The procedure provides in the long term, pain relief and substantial cartilage regeneration. About 80 % of the patients manage to make a full come back in their daily activities and many manage to return to recreational sports. There have even been professional athletes that return to sports after having knee microfracture surgery. Some noteable examples include players such as Jason Kidd, Steve Yzerman, John Stockton, Kenyon Martin and Zach Randolph
One of the main concerns with microfracture surgery is that the procedure doesn't stimulate the development of true, hyaline cartilage. Hyaline cartilage is a type of cartilage that covers all joints in the human body. Unfortunately, microfracture stimulates the growth of fibrocartilage, which is a type of scar tissue. This is why there is always a chance that the cartilage stimulated by a microfracture will not pass the test of time. Often, patient require a second microfracture over the next few years.
Microfracture Rehabilitation
The success of microfracture surgery for articular cartilage regeneration is highly dependant on folllowing strictly the rehab protocol advised by the operating doctor. Progressive, controlled loading of the operated joint and a combnation of a plethora of different rehab exercises is the key to a safe and successful rehabilitation.
The amount of weight bearing allowed during the first weeks post op is limited. This allows the cells to develop new cartilage in the damaged area. In order to keep weight bearing to a minimum, the patient has to use crutches during his daily activities. Usually, after 6 weeks he can start to progressively put and more and more weight until he can finally walk crutch free.
Returning to high impact sports may take up to a year.
Microfracture alternative surgical options
There are many alternative patients for which microfracture has either failed to yield results or they are not good candidates to begin with. Some of these alternative options include:
- Autologous Matrix Induced Chondrogenesis
- Autologous Chondrocyte Implantation
- Mosaicoplasty
History
The operation was first introduced to the medical community by Dr. Richard Steadman. He developed the procedure during the 1980s and early 1990. He first experimented on horses and other mammals and finally on humans.
Almost every year, Dr Steadman presents new improvements to the procedure.