Doctors grew patients’ own cartilage cells in a lab, set them in a gel, and placed them in injured knees. Twelve years later, knee scores were still better than before surgery.
This article covers emerging musculoskeletal and regenerative-medicine research. It reflects what may be coming in the field, not the treatments ADX or its network physicians currently provide.
Why it matters
Cartilage in the knee does not heal well on its own, and many repair methods are only checked for a year or two. This study looked at patients about twelve years after a cartilage-cell procedure. It helps show whether this kind of knee cartilage repair can last, and where it falls short.
Summary
Autologous chondrocyte implantation (ACI) is a cartilage repair approach in which a small piece of healthy cartilage is removed from the patient, its cells are multiplied in a laboratory, and the cells are returned to the damaged area. In this study, the cells were embedded in a collagen type I hydrogel (a product called CaReS) and implanted into knee cartilage defects. A single Austrian center had treated 44 patients between 2006 and 2011. The researchers, led by Markus Neubauer and Stefan Nehrer, tried to re-evaluate them a mean of about 12 years later.
This was a retrospective case series with no comparison group. Of the 44 original patients, 26 were included in follow-up. Twelve completed a clinical examination, six had an MRI, and 14 answered a telephone questionnaire. The group was mixed, including both osteochondritis dissecans lesions (a condition where cartilage and underlying bone loosen) and traumatic injuries.
Among the 12 who were examined, the Lysholm knee score rose from 67.2 before surgery to 81.7, and the modified Cincinnati score rose from 4.5 to 7.4 (both statistically significant). Average pain was 3.6 out of 10 and satisfaction 6.3 out of 10. MRI scoring (MOCART 2.0) averaged 53.3 out of 100, which the authors describe as intermediate repair tissue quality. Two patients needed a total knee replacement because the graft failed to produce enough new tissue, and one had adhesions that were released arthroscopically. Twelve of 14 questionnaire respondents reported no complications.
The findings suggest cell-based repair can give lasting functional improvement for some patients, but the evidence is limited. Only about 59 percent of the original patients were followed up, only a handful had imaging, and there was no control group, so selection bias and chance cannot be excluded. The repair tissue was good but not normal cartilage. Larger studies with longer, more complete follow-up are needed before conclusions about durability can be firm.
Source: Wiener klinische Wochenschrift, Neubauer et al., 2026 (DOI: 10.1007/s00508-026-02794-w)
Research compiled by ADX AI Agent, reviewed by Sean Gallivan