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Arthroscopic Microfracture, Oats Cartilage Procedure
Dr. James Chen, M.D. - In San Francisco, CA

Arthroscopic procedures performed to treat articular cartilage defects of the ankle.

The microfracture technique stimulates cartilage growth by drilling multiple, tiny holes in the defect. This allows stem cells and bone marrow elements to migrate to the bone surface and promote cartilage repair.

The OATS procedure consists of grafting a section of articular cartilage from a non-weight bearing area to the defect of concern. The cartilage graft is removed with the underlying bone. The recipient site is prepared by drilling a socket that will accommodate the graft. The graft is then inserted into the prepared site.

An allograft transplant utilizes an articular cartilage and bone graft similar to the OATS procedure, but the graft is harvested from a cadaver donor.


Dr. Chen's surgical technique for arthroscopic assisted Talar OATs without fibular osteotomy has been featured in Arthroscopy Techniques - The Journal of Arthroscopic and Related Surgery.

Arthroscopic-Assisted Osteochondral Allograft Transplantation for Posterolateral Lesions of the Talus Without Fibular Osteotomy

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Arthroscopic view of large
talar chondral lesion

Open view of
chondral lesion

Cored recipient site
of talus

Donor allograft talus with
OATs plug removed

OATs plug ready
for implantation

OATs plug implanted
into talus

Common Questions about Arthroscopic Microfracture, Oats Cartilage Procedure

What is an OATS surgery?

OATS stands for Osteochondral Allograft Transplantation.

What is a cartilage allograft transplantation?

A cartilage allograft transplantation is different from an OATS because it used in larger cartilage lesions that exceed 1 cm in diameter.

How is an OATS performed?

In an OATS and cartilage and bone plug is taken from another part of the knee or from a cadaver and it is transplanted to a focal area that lacks cartilage. In order to prepare the cartilage defect for implantation of the OATS, an instrument is used to core out a recipient site for the implantation.

How is an allograft transplantation performed?

In a cartilage allograft transplantation a large piece of cartilage and bone are taken from a cadaver and transplanted into the cartilage defect.

How does an OATS heal?

The bony part of the transplant heals to the bony bed of the knee and thus the smooth cartilage surface is fixed in place.

What is the recovery after an OATS or allograft procedure?

A patient must be non-weight bearing for 8 weeks after the surgery on crutches. This is followed by physical therapy.

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