Treatment of Large Cartilage Defects in the Knee by Hydrogel-Based Autologous Chondrocyte Implantation: A 5-Year Follow-Up of a Prospective, Multicenter, Single-Arm Phase III Trial.
P Niemeyer, M Hanus, J Belickas et al.
✦ AI-curated · Sources linked
In 30 seconds
This prospective, multicenter, single-arm phase III trial assessed hydrogel-based autologous chondrocyte implantation (ACI) in 100 patients with focal full-thickness knee cartilage defects measuring 4 to 12 cm². Overall KOOS increased from 39.8 points before treatment to 84.7 at 5 years, a mean increase of 44.1 points (95% CI = 40.4-47.9, P < 0.0001). The prespecified KOOS responder threshold was descriptively met at every assessment from 3 months through 5 years; the 5-year responder rate was 92.8%. Treatment failure at 5 years was 1%, and treatment-related adverse events were mild or moderate.
Key findings
- Overall KOOS rose from 39.8 points preoperatively to 84.7 at 5 years, with a mean increase of 44.1 points (95% CI = 40.4-47.9, P < 0.0001).
- The KOOS responder rate was 92.8% at Year 5 (95% CI = 85.7-97.0), exceeding the study’s >40% endpoint threshold.
- The overall treatment failure rate at 5 years was 1%; treatment-related adverse events were mild or moderate and mostly occurred within the first year.
Why it matters
Large focal cartilage defects can substantially affect knee function. These findings indicate that, in the studied population, hydrogel-based ACI was associated with sustained improvements in patient-reported and other assessed outcomes through 5 years, with few treatment failures and no reported serious safety signal. The results add longer-term evidence for this procedure, while the single-arm design limits conclusions about comparative benefit.
What to keep in mind
The trial was single-arm, so it cannot establish comparative efficacy against other treatments or natural history.