Cartilage Injuries Surgical Treatment

Surgery is considered when:

• Nonoperative treatment has failed: Pain or swelling persists despite a dedicated course of physical therapy and activity modification.
• A loose fragment is present: A piece of cartilage or bone is causing catching or locking and should be repaired or removed.
• An OCD lesion is unstable: The fragment is separating from the surrounding bone or has not healed with nonoperative treatment.
• A focal, full-thickness defect is causing symptoms: A well-defined area of cartilage loss in an otherwise healthy knee, particularly in a young, active patient.

Cartilage restoration is designed for focal defects. Patients with widespread arthritis are generally better served by other treatments.

Arthroscopic Debridement and Loose Body Removal

Through a few small incisions, a camera and instruments are used to smooth unstable cartilage edges and remove loose fragments. This can relieve catching and swelling but does not restore cartilage.

Fragment Fixation

When a traumatic injury or an OCD lesion produces a fragment of cartilage and bone that is in good condition, it can often be fixed back in place with screws or pins, preserving the patient’s own cartilage. This is most successful when performed soon after the fragment separates.

Marrow Stimulation

For small defects, small holes are made in the bone at the base of the defect to release bone marrow cells, which form a fibrocartilage repair tissue. This tissue is less durable than native cartilage, so marrow stimulation is generally reserved for small defects or used alongside other treatments.

Osteochondral Autograft Transfer (OAT)

Small, cylindrical plugs of healthy cartilage and bone are taken from a less important, non-weightbearing area of the patient’s own knee and transferred into the defect. Because the transplanted tissue is the patient’s own true cartilage, this option works well for small defects, particularly in high-demand athletes.

Osteochondral Allograft Transplantation (OCA)

For larger defects, and especially those that involve the underlying bone, such as OCD lesions, Dr. Rynecki Baker may use a fresh osteochondral allograft. A donor graft of living cartilage and bone is precisely sized and shaped to match the patient’s defect and pressed into place. OCA restores both the bone and cartilage in a single procedure and does not require taking tissue from elsewhere in the patient’s knee.

Matrix-Induced Autologous Chondrocyte Implantation (MACI)

MACI uses the patient’s own cartilage cells to regrow cartilage in the defect. It is typically performed in two stages. First, a small biopsy of healthy cartilage is taken arthroscopically and sent to a laboratory, where the cells are grown and seeded onto a collagen membrane over several weeks. In the second stage, the membrane is trimmed to the size of the defect and secured in place, where the cells mature into new cartilage-like tissue. MACI is well suited to larger, full-thickness cartilage defects in adults, including defects on the kneecap and trochlea, and is often preferred when the underlying bone is healthy.

A cartilage repair is only as durable as the environment it is placed in. If the factors that caused the damage are not corrected, the new cartilage is subjected to the same excess stress. Dr. Rynecki Baker evaluates every patient for these factors and addresses them at the same time when needed:

• High tibial osteotomy (HTO): For bowlegged alignment with a defect on the inner side of the knee, the shin bone is realigned to shift weight toward the healthier outer side.
• Distal femoral osteotomy (DFO): For knock-kneed alignment with a defect on the outer side of the knee, the thigh bone is realigned to shift weight toward the inner side.
• Tibial tubercle osteotomy (TTO): For defects behind the kneecap or in the trochlea, repositioning the tibial tubercle unloads the damaged area and improves kneecap tracking, and is often combined with MPFL reconstruction in patients with instability.
• Meniscus transplantation: When the meniscus in that compartment has previously been removed, restoring it helps protect the cartilage repair.
• Ligament reconstruction: An unstable knee, such as one with an ACL tear, is stabilized to protect the repair.

Recovery depends on which procedures are performed. After arthroscopic debridement or loose body removal, most patients return to activity within several weeks. After cartilage restoration, the timeline is considerably longer, because the new tissue must be protected while it heals and matures. Patients can expect a period of protected weightbearing, a brace for certain procedures, and early range of motion to nourish the healing cartilage. Defects on the kneecap or trochlea often allow earlier weightbearing in a brace locked in extension. Return to sport typically takes nine to twelve months or longer, particularly after MACI or when an osteotomy is performed.