Patient Information Resources

1089 Spadina Road
Toronto, AL M5N 2M7
Ph: 416-483-2654
Fax: 416-483-2654

Child Orthopedics
Spine - Cervical
Spine - Lumbar
Spine - Thoracic

View Web RX

« Back

I'm really bummed. I had a surgery called autologous chondrocyte implantation or ACI for short. It was actually two surgeries by the time they harvested my cartilage cells, grew more, and then put them in the hole in my knee cartilage. It's been six months and I still have knee pain, loss of motion, and can't do my normal activities. I guess I have lots of questions. Do I just give it more time? Did I do something wrong? What's the next step? Do I need more surgery? Please tell me what you know.

A recent study from Germany might answer some of your questions. In this study, surgeons took a closer look at factors that might increase the risk of revision surgery after autologous chondrocyte implantation or ACI. ACI is a cell-therapy approach to treat deep or large defects in the knee joint cartilage. It involves using cartilage cells (chondrocytes) to help regenerate articular (joint surface) cartilage. Studies show that in about one-fifth of patients who have this treatment, there is a failure of the cartilage cells to regenerate and fill in the hole. In cases of treatment failure, a second (revision) surgery is required. Surgeons would like to spare patients both the failed results and the need for more surgery. Identifying risk factors that could increase the likelihood of treatment failure would be helpful. Surgeons could screen patients before surgery and perhaps choose a different treatment approach if it looks like there are indicators that autologous chondrocyte implantation (ACI) might fail. To conduct this study, 413 patients who had the first ACI procedure for a full-thickness defect (down to the bone) were followed. Anyone who had a failed response was examined more carefully. Data collected about patients with failed outcomes was analyzed. The kinds of information collected included age, sex (male or female), type of defect (size, location), body mass index (BMI, a measure of obesity), smoking history, and number of previous knee injuries or surgeries. Follow-up was a minimum of at least two years. Some patients were followed for up to 11 years. This next piece of information might be of interest to you. Criteria for a second surgery included continued knee pain, loss of knee function, and MRI evidence of pathology. Just about one-fifth of the group (21.3 per cent) needed revision surgery. They didn't all have the same exact problem. Problems ranged from too much cartilage regrowth (called transplant hypertrophy) to not enough (insufficient regeneration). In some cases, there were loose pieces of cartilage in the joint space or bone cysts that formed. The factors that were most significant for failed ACI included being female, having a previous bone marrow treatment, the use of a periosteum patch to cover the ACI, and previous knee surgery (or surgeries) on that knee. There was no apparent link between age, smoking history, body size, or defect size or location. A periosteal patch is a thin layer of bone harvested from a nonweight-bearing portion of the knee joint used to cover the implanted cartilage cells. It's a bit like placing a manhole cover over an open hole. It protects the healing lesion that has been filled with chondrocytes (cartilage cells). Whenever possible, minimally invasive arthroscopic surgery was done to address the problem. Sometimes the surgeon just had to clean out the area of any bits of debris, bone, or excess cartilage. This procedure is called debridement. This may be all that you need. In some cases, the surgeon opted for a different surgical approach rather than revise or repeat the chondrocyte implantation. Your surgeon is the best one to advise you. If you haven't already gone back for a follow-up appointment, this might be a good time to schedule further evaluation. There could be something simple that can be easily corrected if addressed sooner than later. Imaging studies with X-rays or MRIs might be helpful in showing what's going on and aid the surgeon in making the best choice as to how to change your pain, loss of motion, and decreased function.


« Back

*Disclaimer:*The information contained herein is compiled from a variety of sources. It may not be complete or timely. It does not cover all diseases, physical conditions, ailments or treatments. The information should NOT be used in place of visit with your healthcare provider, nor should you disregard the advice of your health care provider because of any information you read in this topic.

All content provided by eORTHOPOD® is a registered trademark of Mosaic Medical Group, L.L.C.. Content is the sole property of Mosaic Medical Group, LLC and used herein by permission.