October 2009

New Implant Technology Regenerates Knee Cartilage

Hubert Kim, M.D., Ph.D.
Orthopedic Surgeon
Director of the UCSF Cartilage Repair and Regeneration Center

Benjamin Ma, M.D.
Orthopedic Surgeon
Chief of UCSF Sports Medicine and Shoulder Service

Autologous chondrocyte implantation (ACI) surgery, the current treatment for repairing areas of cartilage damage, has shown limited success, partly because it does not stimulate the growth of normal knee joint cartilage, or hyaline cartilage, but rather produces fibrocartilage, the type of cartilage commonly found in scar tissue. In most cases, fibrocartilage does not stand up over time.

A new implant technology, NeoCart, uses a 3-D matrix to protect cells and encourage growth and development of natural cartilage tissue, grown from a patient's own cartilage cells. This technique optimally produces tissue that contains both multiplying cells and a substantial amount of true cartilage cells, and has shown excellent cartilage fill and integration with surrounding cartilage.


Cartilage cells are biopsied from a non-weight bearing area of the patient's knee joint. The cartilage cells, or chondrocytes, are isolated from the cartilage and multiplied using standard tissue culture techniques. The cells are seeded into a unique 3-D collagen scaffold under exacting conditions of high pressure, oxygen concentration and perfusion that mimic the knee's normal experiences, such as walking.

After a few weeks, a 3-D piece of the patient's own neocartilage, having characteristics of maturing native articular cartilage, is implanted into the patient's damaged knee area in a simple procedure that usually takes less than an hour.

A new bioadhesive is used that makes implantation quick and easy.

Within months, the matrix remodels, the cells mature and the cartilage integrates with the host tissue. Advanced MRI imaging developed at UCSF evaluates cartilage development and integration.

NeoCart is currently in Phase III clinical trials. UCSF's Orthopedic Institute is one of the six centers nationwide participating in the study. Patients at UCSF have access to the treatment through study participation.

Patient Criteria

At this time, NeoCart is designed to repair damage to an otherwise healthy knee, but not natural deterioration from age or osteoarthritis. The treatment is recommended for patients with knee cartilage damage or deterioration caused by:

  • Injury or trauma, including sports injuries
  • Repetitive use of the joint
  • Congenital abnormalities in joint structure
  • Endocrine disorders


UCSF Cartilage Repair and Regeneration Center is part of the new UCSF Orthopaedic Institute, the largest center of its kind in Northern California, offering a "one-stop shop" for outpatient orthopedic care, including cutting-edge technology and treatment.

In addition to patient care, the institute conducts basic and clinical research. Currently, researchers are participating in a phase III clinical trial studying NeoCart.

The institute also is participating in research to design the next generation of cartilage regeneration using adult stem cells to grow human cartilage. Using stem cells versus a patient's own cartilage cells has a number of advantages — stem cells can be grown and implanted in very large quantities, compared to cells from a patient, which can be extracted in only limited amounts; and stem cells develop into a more durable joint surface.

Other Resources

For more information, contact the Physician Referral Service at UCSF Medical Center:

Phone (888) 689-UCSF or (888) 689-8273
Email referral.center@ucsfmedctr.org