Fresh osteochondral allograft

A fresh osteochondral allograft (OCA) is a size-matched segment of cadaveric donor tissue — living hyaline cartilage on its native bone — press-fit into the prepared defect. The bone integrates with your bone; the cartilage depends on the survival of the donor's chondrocytes, which is why grafts are stored fresh rather than frozen. It is the only option that restores both mature cartilage and lost bone stock in a single stage — which is why it owns the large-defect and salvage niche.

The survivorship record

The evidence is long series from high-volume centers, remarkably consistent with each other:

• San Diego femoral condyle series (122 patients, median 13.5 years): graft survivorship 82% at 10 years, 74% at 15, 66% at 20. But 47% needed some reoperation and 24% ultimately failed; age over 30 and prior surgery predicted worse outcomes.
• Toronto post-traumatic series (63 patients, mean 21.8 years): survival 91% at 10 years, 84% at 15, 69% at 20, 59% at 25 — and surviving grafts functioned well (mean HSS score 86).
• Pooled across 19 studies (1,036 patients, mean 8.7 years): survivorship 78.7% at 10 years, 72.8% at 15, 67.5% at 20; reoperation 30.2%; failure 18.2%. An earlier pooled review found 86% patient satisfaction.

What the series cannot tell you

There is zero randomized evidence — every number above comes from case series at specialist centers, and the pooled 10-year survivorship range across centers is wide (39–93%), so community results are likely worse than the headline figures. Reoperation is common (30–47%) even when grafts survive. And outcomes degrade in exactly the patients most likely to be offered OCA as salvage: prior surgery, age over 30, and bipolar or patellar lesions. The long-term series are retrospective, with the survivor bias that implies.

Who it is for

OCA is usually first choice for large defects (over 3–4 cm²), defects with bone loss (OCD, avascular necrosis, fracture), and failed prior cartilage repair. For small condylar defects, cheaper options using your own tissue come first.

Logistics gate access in a way no other procedure here shares: a size-matched fresh donor must become available within the viability window (roughly 28 days), so surgery is scheduled around the graft, not the calendar. Availability is largely a North American phenomenon, built on tissue-bank infrastructure. Recovery: protected weight bearing about 6–8 weeks, return to sport commonly 9–12 months.

Questions for your surgeon

• How many OCAs does this center do a year? The published numbers come from high-volume specialist centers.
• What is your own survivorship and reoperation rate?
• I'm over 30 / have had prior surgery / have a bipolar lesion — how do the numbers look for patients like me specifically?
• If the graft fails, what comes next — revision OCA or arthroplasty?
• Bipolar (kissing) lesions do poorly in the data — if that is my anatomy, why is OCA still on the table?

Safety

Standard surgical risks plus allograft-specific ones: theoretical disease transmission (very rare with modern screening), graft subsidence or collapse, delayed or non-union of the bony base, and immune-mediated subchondral changes — grafts are not HLA-matched. Failure typically means revision OCA or joint replacement. The repeatedly called-for RCT against MACI or OATS in the 2–4 cm² overlap zone has never been run; donor logistics make it genuinely hard to do.