Treating Damaged Cartilage
There are several options for treating damaged cartilage. Your doctor will determine which option is right for you based on the type and extent of your knee injury. It is important to note that early intervention may help to prevent damage from spreading to surrounding healthy cartilage and thus prevent further deterioration in the joint surface.
Articular Cartilage Repair
There are various treatment options to address articular cartilage loss, ranging from pain relief to cartilage replacement. Several of the most common treatments are described below.
Arthroscopic Chondroplasty (Debridement)
Using an arthroscope, the surgeon locates the damaged cartilage and trims it away. This prevents any damaged tissue flaking off, which can often irritate the lining of the joint and lead to swelling. This "clean up" surgery of the joint surface is called a chondroplasty. Chondroplasty may relieve pain for a short period of time, but it does not repair the cartilage defect.
Marrow Stimulation Repairs (Microfracture)
In some cases, the body can be stimulated to produce its own repair tissue through an arthroscopic procedure called microfracture. This procedure attempts to repair small cartilage defects by using the body's own marrow stem cells.
Tiny breaks (microfractures) are created in the bone underneath the defect by drilling, abrasion, or using a small surgical instrument. Blood and bone marrow (which contains stem cells) seep out of these fractures, creating a blood clot that releases cartilage-building cells. These techniques may be successful in addressing symptoms in some patients.
Osteochondral Autograft
This technique is similar to a hair-plug transfer. The surgeon removes a small plug of the patient's own cartilage along with the underlying bone from a non-weight bearing part of the joint, and grafts it into the defect. Defects up to 3 cm2, or slightly larger than a thumbnail, may be treated with this technique.
Autologous Chondrocyte Implantation (ACI)
In ACI treatment a biopsy is taken from a healthy part of the patient’s cartilage, their own cartilage cells (chondrocytes) are collected from it and multiplied in a laboratory over a period of weeks to increase the number of cells, and then implanted into the defect to repair it. Because this treatment uses the patient’s own (autologous) cells, there is no risk of rejection. This treatment can be used to repair small, medium and large defects. MACI is a form of ACI.
Allografts
For very large defects that involve bone and cartilage loss, surgeons may use an implant obtained from freshly donated cadaver cartilage and bone. The advantage of donated cartilage and bone is that the implant includes both bone and fully developed cartilage for the repair. However, there may be some risk of infection or tissue rejection using this procedure.