Cartilage Restoration
Background
Articular cartilage is the smooth surface covering the ends of bones in the knee. It allows the joint to move easily and helps distribute force. A focused area of cartilage damage can cause pain, swelling, and difficulty with sports or daily activities. Because cartilage has limited ability to heal on its own, surgery may be considered when a symptomatic defect does not improve with nonsurgical treatment.
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Cartilage restoration includes several procedures. The best choice depends on the size and location of the defect, whether the bone beneath it is damaged, the condition of the rest of the knee, and the patient’s activity goals. These procedures are generally intended for a localized defect rather than widespread knee arthritis.
The Surgical Procedure
Cartilage restoration may be performed arthroscopically through small incisions or through a larger incision, depending on the procedure and the technique. During surgery, the damaged area is assessed and prepared. Meniscus injuries, ligament instability, or patella tracking problems may also need treatment to protect the restored surface.
Microfracture or Drilling
Microfracture and drilling create small openings in the bone beneath a cartilage defect. This allows cells from the bone marrow to enter the area and form repair tissue. These procedures may be considered for selected small defects. The new surface is primarily fibrocartilage, which differs from the original joint cartilage.
OATS: Osteochondral Autograft Transfer
OATS transfers one or more small plugs of healthy cartilage and underlying bone from a less loaded part of the patient’s knee into the damaged area. It replaces both the cartilage surface and the bone beneath it.
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OATS is often considered for smaller, contained defects. Because the graft comes from the patient’s own knee, the size and number of plugs that can be taken are limited.
OCA: Osteochondral Allograft Transplantation
OCA uses carefully matched donor cartilage and bone to replace the damaged portion of the joint. It can address larger defects or areas where the underlying bone is also injured. The graft is shaped to fit the defect and secured within the patient’s bone.
MACI: Matrix-Induced Autologous Chondrocyte Implantation
MACI is a two-stage procedure that uses the patient’s own cartilage cells. During an initial arthroscopy, a small sample of healthy cartilage is collected. The cells are grown in a laboratory on a collagen membrane. At a later surgery, that membrane is shaped and placed into the cartilage defect.
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MACI may be considered for selected full-thickness cartilage defects, including larger areas without substantial damage to the underlying bone.
Recovery Timeline
Cartilage needs time to heal and adapt to weight bearing. The recovery plan varies substantially with the procedure, the location and size of the defect, and any additional surgery performed.
Early Recovery (Weeks 1 - 6)
The priorities are protecting the treated area, controlling swelling, and restoring knee motion. Crutches are commonly needed, and weight bearing may be limited. Physical therapy begins with a plan tailored to the procedure.
Intermediate Recovery (Weeks 6 - 12)
Weight bearing and strengthening progress as allowed. Therapy focuses on walking normally, regaining motion, and improving muscle control without overloading the healing surface.
Late Recovery (Months 3 - 6)
Strength, balance, and endurance continue to improve. Higher impact activity is introduced only when the treated area and the rest of the knee are ready.
Return to Sport (Months 6 - 12 and Beyond)
Return to running and sports varies by procedure. Some patients return sooner after a small OATS procedure, while recovery after OCA or MACI may take nine to twelve months or longer. Clearance depends on symptoms, swelling, strength, movement quality, and the demands of the sport.
What to Expect
Pain Management
We utilize a multimodal approach including a nerve block when appropriate, oral medications, and ice therapy to minimize the postoperative pain and to limit narcotic use. Swelling and discomfort are expected early on, but most patients find their pain very manageable with this comprehensive approach.
Protecting the Graft
Patients often feel better before the cartilage restoration has fully matured. Following weight bearing and activity restrictions is important, even when pain has improved. Rehabilitation is gradual because the restored surface must tolerate increasing force over time.
Long-Term Outlook
The goal of cartilage restoration is to relieve symptoms and preserve your natural knee for as long as possible. Results can last many years, but the durability of treatment varies with the cartilage injury and the overall health of the knee.