MACI: New Tool for Cartilage Repair

By Daniel M. Myer, MD
Wednesday, December 19, 2018
Specialty: 

In the past 30 years, orthopaedic knee surgery has come a long way. With recent advancements in medicine and technology, it’s now possible to preserve a patient’s knee. The goal is to replace one’s own damaged areas with new, healthy cartilage — and not just replace damaged tissue with artificial measures, such as metal and plastic.

Cartilage preservation surgery using Matrix Autologous Chondrocyte Implantation (MACI) provides that opportunity. Developed by a Cambridge, Massachusetts-based company, Vericel, MACI gives surgeons a new tool to repair cartilage injuries and possibly prevent more serious conditions. It is especially beneficial for younger, weekend warrior type patients who have a contained defect to their cartilage, and not generalized arthritis.

Invented in 1987 by Lars Petersen in Sweden, Autologous Chondrocyte Implantation (ACI) was the first of its kind to treat large cartilage defects in the knee, and it has continued to evolve over the last 30 years. Perfected in Europe for many years before its U.S. FDA approval in 2016, MACI is the newest generation of cartilage transplantation that can preserve a patient’s knee cartilage. Based on research to date, MACI has shown to be more effective than microfracture for lesions larger than three square centimeters. Data from Europe indicates MACI to be better than microfracture in terms of pain relief, clinical outcomes, patient satisfaction and function.


Daniel M. Myer, MD

MACI is an alternative to cadaver tissue and even knee replacement in patients who want to maintain an active lifestyle. This process involves a two-stage surgery. First, we harvest several millimeter pieces of non-weight bearing, non-important, cartilage via a simple knee scope. Using sterile technique, the cartilage specimens are sent to Vericel. While the patient continues conservative therapy and inflammation management, insurance authorization is sought when the MACI procedure is deemed necessary. During a 3 week process, Vericel grows the patient’s own cartilage cells on a healthy collagen matrix, which is now full of millions of living chondrocytes. We then perform a second operation where this cell rich matrix is placed into the defect, and fibrin glue secures the transplant. Based on a multitude of both clinical and histological bench research, the hyaline cartilage that forms is far better than the fibrocartilage that would form from other types of cartilage restoration procedures, such as microfracture.

While MACI is expensive, insurance companies have stepped up to cover most Americans for the procedure. Although this procedure is a financial endeavor, it performs two very important functions. First, it is a less expensive, and better functioning, alternative than arthroplasty at a young age. Second, it restores a priceless quality of life for the active patient. Vericel has trained more than 700 surgeons and hopes to expand the number of patients receiving the therapy, though not everyone is eligible.


Dr. Daniel Myer is a board-certified, fellowship-trained orthopaedic surgeon practicing with Crystal Clinic Orthopaedics Center (CCOC). Headquartered in Akron, CCOC is one of the first in Northeast Ohio to offer MACI. Dr. Myer specializes in sports medicine, arthroscopic surgery of the shoulder and knee, as well as shoulder and knee replacement surgeries.