Cartilage Repair Rising, Reop Rates Falling: New UCSF Study

In an effort to assess the last 10 years of autologous chondrocyte implantation, as well as who is at a higher risk of reoperation or conversion to knee replacement surgery, researchers from the University of California, San Francisco (UCSF) took a look at 2,010 patients who underwent autologous chondrocyte implantation between 2010 and 2020.

Their study, “Utilization of Autologous Chondrocyte Implantation in the Knee is Increasing While Reoperation Rates Are Decreasing Despite Increasing Pre-Operative Comorbidities,” was published in the October 7, 2022, edition of Arthroscopy.

Drew Lansdown, M.D., assistant professor in residence in the Department of Orthopaedic Surgery at UCSF, and co-author on this work told OTW, “There have been multiple prior studies on outcomes after cell-based cartilage restoration with autologous chondrocyte implantation and matrix-induced autologous chondrocyte implantation. Studies have demonstrated improvement in patient-reported outcomes with both of these surgical techniques, with the newest generation of matrix-induced autologous chondrocyte implantation implant technology being introduced in 2017.”

The team found a 90-day reoperation rate of 2.24% and an overall reoperation rate of 30.4% (average follow up was 4.8±3.3 years).

The most common reoperations included chondroplasty, meniscectomy, and microfracture.

Researchers found an increased rate of autologous chondrocyte implantation from 2017-2019 (5.53/100,000) compared to 2014-2016 yet the re-operation rate was lower.

Autologous chondrocyte implantations performed from 2017-2019 were associated with a decreased risk of reoperation within two years as compared to 2014-2016. In the entire autologous chondrocyte implantation group, older age and tobacco use were associated with increased risk of conversion to arthroplasty.

“In this study,” Dr. Lansdown told OTW, “we also identified patient demographic factors that may be associated with complications and reoperations after matrix-induced autologous chondrocyte implantation. Female patients had a higher rate of reoperation, while older patients and tobacco users had a higher rate of conversion to knee replacement surgery. These factors may help guide surgeons in counseling patients who may not benefit from this surgery.”

“We observed that the utilization of matrix-induced autologous chondrocyte implantation has increased amongst patients in the PearlDiver database since the introduction of new technology in 2017. Most importantly, we found that the complication and reoperation rate for patients undergoing matrix-induced autologous chondrocyte implantation was actually lower after 2017 compared to earlier, when the previous generation of technology was in use.”

“I had expected that the utilization rates of matrix-induced autologous chondrocyte implantation would have increased since 2017 as the procedure has become technically simpler with the newer technology. I was surprised that the complication and reoperation rates were lower, as I had expected this procedure may have been used too broadly with the increased utilization.”