Articular Cartilage Defect Surgery
Surgery for Knee Cartilage Injuries
When a knee cartilage lesion causes pain, surgery may be recommended. If the lesion is not causing symptoms, however, your SROSM surgeon will weigh many factors before recommending surgery, such as the patient's age and lifestyle, the overall condition of the knee, and how bad the lesion actually is.
Even if patients have pain, they may not have surgery right away. Instead, your surgeon may start by recommending ways to manage the symptoms, including:
- Applying heat or ice
- Working with a physical therapist
- Wearing a knee brace or shoe orthotic to improve knee alignment to ease pressure on the sore knee
- Taking prescription medication
To determine if surgery is necessary, the orthopedic surgeon will conduct a physical exam and order imaging tests to learn as much as possible about the condition of the knee. An arthroscope may also be used to check the location, size, and depth of the lesions. Learn more about the types of lesions on the articular knee cartilage.
Many types of surgery have been developed for repairing articular cartilage in the knee. When the decision is made to go ahead with surgery, your orthopedic surgeon will assess your situation to determine if the cartilage needs to be repaired or restored.
Reparative Surgery: Cell Stimulation Methods
Reparative surgery procedures are used to stimulate the body to begin healing the injury. They are considered reparative surgeries because the lesion mainly fills in with fibrocartilage.
Cell stimulation methods can include:
- Arthroscopic debridement: a procedure in which a tiny camera is inserted into the knee during surgery to see into the joint and clean it up by trimming rough edges of cartilage and removing loose fragments.
- Abrasion arthroplasty: a procedure in which the surgeon carefully scrapes off the hard, polished bone tissue from the surface of the joint. The scraping action causes a healing response in the bone.
- Microfracture: a procedure in which the surgeon uses a blunt awl (a tool for making small holes) to poke a few tiny holes in the bone under the cartilage. Getting to the layer of bone under the cartilage triggers the body to start forming new cartilage inside the lesion.
Restorative Surgery: Substitution and Replacement Methods
In these procedures, tissue is placed inside the lesion in hopes of restoring the normal structure and function of the original cartilage. The stimulation methods and these newer procedures are showing improved results in helping people return to normal activity.
Substitution and replacement methods can include:
- Periosteal and perichondral grafting: a method involving implanting tissues from the covering of bone and cartilage into the lesion. These procedures are still in the experimental stage, but could eventually become a way for surgeons to restore the articular cartilage.
- Autologous chondrocyte implantation: a procedure in which the surgeon takes a few chondrocytes cells from inside the knee cartilage, to be grown in a laboratory. Later on, during a second surgery, the newly-grown cartilage is implanted into the lesion.
- Osteochondral autograft: a procedure in which the surgeon grafts a small amount of bone (osteo) and cartilage (chondral) from patient to put into the lesion.
- Osteochondral allograft: this procedure is very similar to the osteochondral autograft, however, the tissue used does not come from the patient. Instead, tissue is taken from another person, much like using donor hearts, kidneys, and other organs.
Both the osteochondral autograft and osteochondral allograft procedures have mostly been used to treat osteochondritis dissecans (OCD), a condition where a chunk of the cartilage and the layer of bone beneath have died. The fragment often gets dislodged and becomes a loose body in the joint.
To learn more about OCD, download our educational document A Patient’s Guide to Osteochondritis Dissecans of the Knee.
Rehabilitation After Surgery
After surgery, the joint surface must be protected while the cartilage heals. With the exception of those who undergo a simple debridement, patients will be instructed to avoid putting too much weight on their foot when standing or walking for up to six weeks. This gives the area time to heal. People treated with an allograft are often restricted in their weight-bearing for up to four months.
Your SROSM surgeon will also have you work with a physical therapist after surgery. The goal of physical therapy is to help you keep your pain under control, ensure safe weight-bearing, and improve your strength and range of motion.
You can learn more about articular cartilage injuries by downloading our educational document A Patient’s Guide to Articular Cartilage Problems of the Knee.