What Is Microfracture Surgery?
A microfracture procedure creates small holes in the bone. The surface layer of bone, called the subchondral bone, is hard and lacks good blood flow. By penetrating this hard layer, a microfracture allows the deeper, more vascular bone to access the surface of the joint. This deeper bone has a rich blood supply, and the cells can get to the surface layer to stimulate cartilage growth.
How Does it Work?
This procedure allows blood and stem cells to form a clot in the area of the cartilage defect. These cells have the ability to form a cartilage layer within the defect. In this way, the body is able to repair the damaged area of cartilage by stimulating blood flow to the defect.
Who Is a Good Candidate for Microfracture Surgery?
There are some factors that can determine whether you are likely to experience a good outcome from having microfracture surgery.
Alternatives
Microfracture surgery is generally considered the first-line treatment for cartilage damage in the knee joint. Before deciding to have microfracture surgery, you and your surgeon will discuss other treatments for cartilage defects, such as cartilage transfer and cartilage implantation.
The success of these surgical options has been shown to be no better than microfracture, while the risks and costs of microfracture are dramatically less. Some of these other surgical options are generally done for athletes who have failed to improve after microfracture surgery.
Procedure
A microfracture can be performed as part of arthroscopic knee surgery. Other joints can be treated similarly, also by arthroscopic surgery.
During the procedure:
First, the area undergoing microfracture is prepared by removing any loose or damaged cartilage. The area undergoing microfracture should be less than about 2 centimeters in diameter and have good, healthy surrounding cartilage. A small, sharp pick (awl) is used to create the small microfracture holes in the bone. The number of microfractures created depends on the size of the joint being treated. Most people with a 1- to 2-centimeter area of damage require five to 15 small microfracture holes in the bone.
Recovery and Rehabilitation
One of the keys to successful treatment is appropriate rehabilitation following microfracture surgery. Rehabilitation must protect the area treated by microfracture while maintaining the strength and motion of the knee joint.
Most people need to use crutches after surgery. Often, a knee brace will be recommended. And in some situations, a motion machine to bend the knee may be used.
Outcomes and Limitations
Microfracture can be an excellent procedure, providing substantial pain relief. One of the concerns with microfracture is that it does not stimulate the growth of normal joint cartilage.
There are many types of cartilage, and one of these (hyaline cartilage) is normally found on the joint surface. Microfracture stimulates the growth of another type of cartilage commonly found in scar tissue (called fibrocartilage).
Unlike hyaline cartilage, fibrocartilage does not have the same strength and resiliency as cartilage normally found in a joint. Therefore, there is a chance that the cartilage stimulated by a microfracture procedure will not stand up over time.
A Word From Verywell
Microfracture surgery is popular because it is safe, relatively easy to perform, and comparatively inexpensive to other cartilage stimulation surgical procedures. In general, people who undergo microfracture surgery do reasonably well in the short to mid-term.
There are questions, however, about the durability of microfracture repair, and most surgeons agree that the cartilage that heals within a microfracture defect is not nearly as durable as normal cartilage.
