Autologous Chondrocyte Implantation (ACI)
This service is performed as a two stage procedure. The first stage is usually completed arthroscopically with a biopsy of the cartilage being taken. This constitutes harvesting of the chondrocytes and is reported with CPT code 29870 as indicated by parenthetical notes in the CPT manual. Keep in mind that the diagnostic arthroscopy code is never reported with a surgical arthroscopy, so if the physician performs another procedure like a chondroplasty, then only report 29877 without adding 29870 for the chondrocyte harvesting.
After collection, the chondrocyte sample is sent to a lab where the original small number of harvested cells are set in an environment that allows them to proliferate.
Once the growth stage reaches 10-12 million cells the specimen is returned to the physician where it can be implanted back into the patient’s knee.Some key words to recognize would be Genzyme Corporation and Carticel. Carticel is the only FDA approved product for ACI implantation and it is developed by Genzyme Corporation.
Once the physician is in possession of the Carticel sample, their patient is brought back to the ASC for a second stage implantation procedure which is performed through an open approach. Once the site of articular cartilage damage has been accessed a periosteal patch is fixed over the defect. Periostium is the bones natural covering and a piece of this is harvested from the tibia to be used as a “patch”. When placing the periostium an area of the patch is left open and Carticel is introduced into the defect before final closure and sealing of that area. The knee is closed. ACI implantation is reported with CPT code 27412 - Autologous chondrocyte implantation, knee.
Carriers have specific coverage restrictions that a coder should be familiar with. For example, the ACI procedure IS NOT a treatment for patients with osteoarthritis and the facility should expect a denial when this diagnosis is an indication for the procedure. Also, the ACI is only indicated for articular cartilage defects of the femur (medial/lateral condyles or trochlea). When performed on the patella or any other joint, an ACI procedure is considered investigational/experimental and will not be covered.