Minimally Invasive Treatment for Knee pain

Knee joint preservation and cartilage restoration is a treatment option for knee pain. This surgery is done through minimally invasive procedures to repair articular cartilage. Articular cartilage is the smooth surface that caps the ends of bones and allows joints to glide smoothly with motion. Healthy cartilage makes joints move easier.

Many of these procedures are performed arthroscopically using a small camera placed through tiny incisions. In most cases, patients can return home on the same day as the surgery or, in some cases, only stay in the hospital overnight.

In some cases, these procedures can reduce or prevent the onset or progression of arthritis and prolong the life of the knee joint. In turn, this may reduce the risk of needing a joint replacement.

Knee Cartilage Injuries

The most common way to injure your knee cartilage is by a traumatic blow to the knee or twisting injury while your foot is planted. Other ways cartilage is injured are alignment of your knee (genetic), dislocations, and normal wear and tear.

Symptoms of Knee Cartilage Injury

Symptoms are different for all people but the most common are:

  • an ache that gets worse with activity,
  • a sharp pain with certain movements, and
  • locking of the knee where it gets stuck in a position and will not move.

Knee Cartilage Restoration Procedures

Because cartilage does not heal itself well, cartilage procedures stimulate new cartilage to grow. Many restoration procedures to restore articular cartilage are done with a camera (arthroscopy).

During arthroscopy, your surgeon makes two or three small incisions around your joint using an arthroscope. Sometimes surgeons need more direct access to the affected area so longer, so they might need to make larger incisions. Sometimes it is also necessary to repair other problems in the joint, such as meniscal or ligament tears at the same time. In general, recovery from an arthroscopic procedure is quicker and less painful than atraditional, open surgery. Your doctor will discuss the options with you to determine whatkind of procedure is right for you.

The most common procedures for cartilage restoration are:

  • Microfracture/drilling,
  • Cell therapy: DeNovo,
  • Autologous chondrocyte implantation (ACI),
  • Osteochondral autograft
  • Transplantation, and
  • Osteochondral allograft transplantation.


The goal of microfracture is to stimulate the growth of new fibrocartilage to fill defects by creating new blood supply. The surgeon will use sharp tools to make multiple holes in the joint surface. Then holes are made in the bone beneath the cartilage. This triggers the healing process in the body to start. The body bring new blood supply to the joint surface, which also brings new cells that will form the new cartilage.

Microfracture can be done with a camera. Your orthopedic surgeon may recommend microfracture if you are a young patient with small cartilage injuries and healthy bone.

Like microfracture, drilling can also help the body produce healthy cartilage. Your surgeon makes multiple holes through the injured area in the bone with a surgical drill or wire. This creates a healing response in the bone. Drilling can also be done with a camera.

Osteochondral Autograft & Allograft Transplants


In osteochondral autograft transplantation, we transfer cartilage from one part of the joint to another. Your surgeon will take healthy cartilage tissue from an area of the bone that does not carry weight (non-weight bearing). Then they match it to the surface area that is damaged and put it in place. This leaves a smooth cartilage surface in the joint.

Your surgeon may take a single plug of cartilage or use multiple plugs. A procedure using multiple plugs is called mosaicplasty.

Osteochondral autograft is used for smaller cartilage defects. This is because the healthy graft tissue can only be taken from a limited area of the same joint. In some cases it can be done with an arthroscope but most require an open incision.


If a cartilage defect is too large for an autograft, your surgeon might suggest an allograft. An allograft is a tissue graft taken from a cadaver donor. Before the procedure it is sterilized in the laboratory and prepared. It is also tested for any possible disease transmission.

An allograft is typically larger than an autograft. Your surgeon will shape it to fit the exact contour of the injury site and then press fit into place. Allografts are typically done through an open incision.

Juvenile Allograft Implantation (DeNovo®)

DeNovo® is a single step procedure. New cartilage cells that have been donated by young people are implanted in the cartilage injury site (defect).

The surgeon uses either an open or arthroscopic (camera) procedure to prepare the cartilage defect. They then place the new, healthy cells in the injury site and secure it with a special dissolvable sealant: fibrin glue. These cells then grow in the injured area and create new, healthy cartilage.

Juvenile allograft implantation or DeNovo® is most useful for younger patients who have single defects that are larger than 2 cm in diameter. DeNovo® has the advantage of a single step procedure and using very young, healthy cartilage cells that have excellent healing.

Autologous Chondrocyte Implantation (ACI)

ACI is a two-step procedure. New cartilage cells are grown and then implanted in the cartilage defect. First, healthy cartilage tissue is removed from a non-weight bearing area of the bone. This step is done as an arthroscopic procedure.

The tissue which contains healthy cartilage cells is then sent to the lab. New cells are grown over three to five weeks. Your surgeon will then perform an open surgical procedure to prepare the cartilage defect. They then inject the newly grown cells into the defect.

ACI is most useful for younger patients who have single defects larger than 2 cm in diameter. ACI has the advantage of using the patient’s own cells, so there is no danger of a patient rejecting the tissue. It does have the disadvantage of being a two-stage procedure that requires an open incision. It also takes several weeks to complete.