Cartilage repair compared
STACi vs Microfracture: Which Cartilage Repair Is Right for You?
A fair, side-by-side look at two very different ways to treat damaged cartilage.
Reviewed byProfessor Paul Lee MBBch, FRCS (Tr & Orth), PhDCartilage and joint preservation expertiseQuick answer
Microfracture drills tiny holes in the bone to trigger a blood clot that heals as scar-type fibrocartilage. It is quick, cheap and reasonable for small cartilage defects under about 2 cm². STACi instead regrows your own hyaline-like cartilage on a 3D scaffold, and is built for larger, deeper damage where microfracture’s weaker repair tends not to last.
For a small, isolated defect, microfracture is a sensible first step. For larger damage — or when durability matters most — STACi rebuilds cartilage closer to the real thing.
Microfracture vs STACi at a glance
| What to compare | Microfracture | STACi |
|---|---|---|
| What it does | Drills small holes in the bone so it bleeds and forms a clot that heals over | Rebuilds cartilage using your own cells grown on a 3D scaffold, placed in the joint |
| Tissue it grows | Scar-type fibrocartilage — softer, less durable than natural cartilage | Hyaline-like cartilage — the load-bearing type, grown in depth |
| Defect size it suits | Small defects, generally under about 2 cm² | Larger and deeper defects, including those too big for microfracture |
| Operations | One | One in most cases (lab step brought into theatre) |
| Extra tissue harvested | No | No |
| Joints | Any | Any joint |
| Durability | Repair can wear or break down over time, especially in larger or high-load areas | Aims for a durable, living cartilage surface |
| UK availability & cost | Widely available, including on the NHS; low cost | LCC only; from £28,000, all-inclusive |
When microfracture may be the better choice
- Your cartilage defect is small — generally under about 2 cm² — and clearly defined.
- You want the least invasive, lowest-cost first option, and are comfortable that the repair tissue is scar-type rather than natural cartilage.
- You need a widely available procedure, including on the NHS, without travelling to a specialist centre.
- A single, contained lesion where a good result from a simpler operation is realistic.
When STACi is the better choice
- Your damage is larger or deeper than microfracture reliably treats.
- You have already had a microfracture that has not held up, and the defect has returned or grown.
- You are active or relatively young, and durability of the repair matters more than a quick, cheap fix.
- You want hyaline-like cartilage — the real load-bearing surface — rather than fibrocartilage.
- You want to preserve your own joint and delay or avoid a future replacement.
Microfracture is not a failure of a technique — for the right small lesion it is a perfectly reasonable operation, and it remains one of the most common cartilage procedures worldwide. Its limitation is biological: the tissue it grows is a scar-type stand-in, and in larger or higher-load areas that stand-in tends not to last. STACi exists for exactly those cases — where a longer-lasting, hyaline-like repair is worth a more involved procedure. The honest way to choose between them is an imaging review of your specific defect.
Frequently Asked Questions
Is microfracture or STACi better for my knee?
It depends on the size and depth of your cartilage damage. For a small, isolated defect (generally under about 2 cm²), microfracture is a reasonable, low-cost first step. For larger or deeper damage — or if a previous microfracture has not lasted — STACi’s scaffold-based regeneration is designed to rebuild a more durable, hyaline-like surface. An imaging review is the only way to say which suits you.
Why does microfracture grow “weaker” cartilage?
Microfracture works by making the bone bleed, so the body forms a clot that heals into fibrocartilage — a scar-type repair. Fibrocartilage is softer and less hard-wearing than the natural hyaline cartilage that normally lines a joint. It can do well in small areas, but under heavy or repeated load it tends to break down sooner. STACi instead grows hyaline-like cartilage using your own cells.
Can I have STACi if I have already had a microfracture?
Often, yes. A microfracture that has not held up is one of the situations STACi is designed for. Previous cartilage surgery does not automatically rule you out — but it does need to be reviewed, because it can affect the defect and the surrounding bone. Book an assessment so your imaging can be looked at properly.
Is microfracture available on the NHS and STACi is not?
Microfracture is widely available, including on the NHS, and is inexpensive. STACi is a private, UK-exclusive procedure offered only at London Cartilage Clinic and is not routinely available on the NHS. STACi costs from £28,000, all-inclusive. We can provide an itemised invoice if you wish to submit a claim independently.
How much better is STACi’s durability than microfracture’s?
STACi aims for a durable, living cartilage surface rather than a temporary repair, and hyaline-like cartilage is generally more hard-wearing than fibrocartilage. We report outcomes qualitatively here and give you written, defect-specific expectations at consultation. See the STACi evidence page for what the studies show.
Still have more specific concerns?
Free Discovery CallNot sure which one you need?
A fifteen-minute discovery call is free, or book a consultation to have your imaging reviewed by the surgeon who would perform the procedure.