Knee Cartilage Repair
A surgeon can use special tools to remove frayed and tattered cartilage and smooth the remaining cartilage surface. This contouring of cartilage reduces joint friction, which in turn can:
• Reduce knee pain
• Restore knee function
• Potentially slow down future cartilage degeneration
The medical term for surgery to reshape knee cartilage is knee chondroplasty—“Chondro” refers to cartilage and “plasty” means to form or mold. Chondroplasty may be performed on a knee’s articular cartilage, meniscus, or both.
Knee chondroplasty is often done in conjunction with debridement. During knee debridement the surgeon removes potential irritants to the joint, such as loose pieces of cartilage, and flushes the joint with a saline solution (lavage).
Knee Cartilage Regeneration
There are three common knee cartilage regeneration techniques that use bleeding to spur cartilage healing:
• Knee microfracture, which requires the damaged cartilage to be cleared away completely. The surgeon then uses a sharpened tool called an awl to pierce the bone.
• Knee drilling, which uses a drill or wire to make tiny holes the bone. There is some evidence that the heat from the drill can cause unnecessary injury to nearby tissue, which can eventually lead to bone cysts or other problems.
• Knee abrasion arthroplasty, which requires the damaged cartilage to be completely cleared away. The surgeon then uses a special tool to scrape and roughen the affected bone’s surface.
These regeneration techniques are used to treat damaged articular cartilage. They cannot be used to treat a damaged knee meniscus.
Knee Cartilage Replacement
Osteochondral autograft transplantation uses cartilage from the patient.
- The surgeon removes a small (<1cm), round plug of healthy cartilage—and a tiny bit of underlying bone—from a non-weight-bearing area of the knee joint. The surgeon transfers the plug to the area being treated.
- This OATs procedure can be used to repair one or more relatively small cartilage defects in a knee. When more than one plug is used to treat a single cartilage defect, the procedure is called mosaicplasty.
- The surgery is usually done arthroscopically.
- The surgeon removes a circular plug of healthy cartilage from an outside donor.
- An allograft is usually used when cartilage defect being treated is too large for an autograft (≥2cm).
- This surgery usually requires an open incision.
- First, the patient undergoes arthroscopic surgery to remove a small piece of healthy cartilage from a non-weight bearing area of the knee joint. That cartilage is cultured, allowing new cartilage cells grow.
- Three to five weeks after the first surgery, a second surgery is performed to implant the newly grown cartilage cells into the affected knee joint.
- This second surgery is not done arthroscopically; it requires an open incision.
- This procedure may be recommended when the cartilage injury is large (up to several centimeters) or there are multiple cartilage injuries to repair