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Microfracture surgery for cartilage defects, by a consultant knee surgeon.

The workhorse operation for a small, focal cartilage defect - with an honest comparison to AMIC, MACI and osteochondral grafts before you agree to anything.

See indicative pricing
A radiographer guides a patient onto the bed of an advanced 3 Tesla MRI scanner in a London imaging suite

Indicative pricing

What private microfracture and cartilage repair costs in the UK.

Indicative ranges across UK private providers.

In short

£3,000–£6,000, home the same day.

Procedure Indicative range
Microfracture (small defect, <2 cm²) £3,000–£6,000
Nanofracture (finer perforations) £3,500–£6,500
AMIC (microfracture + collagen membrane) £5,000–£8,000
MACI (2-stage, cell-based - larger defects) £8,000–£12,000
Diagnostic knee arthroscopy £2,200–£3,500
Consultation and MRI review £250–£450

Prices vary by clinic, by the surgeon, by whether AMIC augmentation or a membrane is used, and by whether concurrent meniscal or ligament work is needed. Microfracture is routinely covered by UK insurers when clinically indicated; MACI cover is more variable.

The problem

The right operation for the right defect - not the one the theatre list happens to know.

Cartilage repair is a small field with big trade-offs. Microfracture is fast, cheap and works for small defects; MACI, AMIC and OATS work better for larger ones. Getting the choice right matters more than the operation itself.

  • Small defect, active patient?

    Microfracture (or nanofracture) is the honest workhorse - quick, day-case, insurance-friendly.

  • Larger or uncontained defect?

    AMIC, MACI or an osteochondral graft usually outperforms microfracture at 5–10 years. We say so.

  • Unstable or malaligned joint?

    Ligament reconstruction or an osteotomy comes first. Any repair on top of a bad mechanical environment fails.

When it helps

When microfracture is the right step.

The situations where marrow stimulation earns its place, plus the ones where a different operation is honestly the better answer.

  • Focal cartilage defect on MRI

    A symptomatic Outerbridge grade III–IV chondral lesion under 2–3 cm², well-shouldered and contained by healthy cartilage.

  • Locking, catching or giving way

    A loose flap of cartilage catching in the joint - often felt as a click, sharp pain or momentary buckling on rotation.

  • Post-traumatic knee cartilage injury

    A twisting injury, dislocated patella or old ACL tear that has left a discrete cartilage defect on the femoral condyle or trochlea.

  • Osteochondritis dissecans (OCD)

    A small OCD fragment or crater in a young or middle-aged patient where the bed can be prepared and stimulated.

  • Talar dome lesion in the ankle

    A symptomatic osteochondral lesion of the talus - microfracture is also used at the ankle and, less often, the shoulder and hip.

  • Younger, motivated patient

    Under 45–55, active, willing to commit to a long and disciplined rehab - the group where fibrocartilage repair holds up best.

  • Alternative to earlier arthroplasty

    A joint-preserving option when a replacement feels too soon - buying time and function in a knee that is not yet worn out.

  • Not for: generalised osteoarthritis

    Kellgren–Lawrence grade 3–4, kissing lesions, uncontained defects or an unstable knee are not helped by microfracture - a different plan is needed.

Technique options

Microfracture is one of several cartilage-repair options.

What each option actually involves - and which is honestly the best fit for the defect on your MRI.

  • Microfracture

    The workhorse. 1.5–2 mm awl perforations 3–4 mm apart through the subchondral plate, creating channels for marrow stem cells to form fibrocartilage.

  • Nanofracture

    Finer 1 mm needles at closer spacing. Theoretical improvement in fibrocartilage quality with less subchondral disruption - same rehab.

  • AMIC (matrix-induced chondrogenesis)

    Microfracture plus a collagen membrane (Chondro-Gide) glued or sutured over the defect. Better outcomes for defects 2–4 cm² than microfracture alone.

  • BST-CarGel

    A chitosan-based scaffold mixed with blood applied over a microfracture bed - an alternative augmentation for the right defect.

  • MACI (matrix-induced ACI)

    Two-stage cell-based repair - cartilage cells harvested, cultured, then re-implanted on a membrane. Superior for defects over 2 cm² with more durable results. See our knee preservation page.

  • OATS / osteochondral autograft

    Plugs of healthy cartilage and bone moved from a non-weight-bearing site into the defect. Suited to small–medium contained lesions.

  • Osteochondral allograft

    Donor bone-and-cartilage plug for larger defects, uncontained lesions or revision of a failed microfracture.

  • Realignment or ligament surgery first

    A malaligned or unstable joint destroys any cartilage repair. Osteotomy or ACL reconstruction comes first - see our realignment and knee preservation pages.

Safety and honest expectations

What to expect afterwards - honestly.

Microfracture is a safe day-case operation, but its long-term success depends on realistic expectations, disciplined rehab and the right defect for the technique.

  • The rehab is the operation

    6–8 weeks touch-toe weight-bearing and CPM 6–8 hours a day for 6 weeks are what make microfracture work. Skipping the rehab wastes the surgery.

  • Fibrocartilage, not native cartilage

    The repair tissue is type I collagen fibrocartilage - functional, but mechanically inferior to the type II hyaline cartilage you were born with.

  • Realistic expectations at 5 and 10 years

    Around 60–80% of patients feel better at 2 years; that drops to about 60% at 5 years and 40–50% at 10. Fibrocartilage does not wear as well as hyaline.

  • No impact for 6–9 months

    No running, jumping or pivoting for six to nine months, and no contact sport for nine to twelve. This is not negotiable if you want the repair to hold.

  • Transient bone-marrow oedema

    A subchondral cyst or oedema on post-op MRI is common in the first year and usually settles - not, on its own, a sign of failure.

  • Hypertrophic overgrowth

    Occasionally the repair tissue overgrows and causes catching or pain - a small arthroscopic debridement usually settles it.

  • Younger, smaller, non-weight-bearing = best

    The best outcomes are in patients under 40, defects under 2 cm², and lesions in less-loaded areas like the trochlea. We say so honestly.

  • When MACI or OATS is the better call

    Defects over 2–3 cm² generally do better with MACI, AMIC or an osteochondral graft. We would rather steer you correctly than sell the smaller operation.

  • Red flags

    A hot, swollen joint with fever, calf pain or breathlessness after surgery are not normal - call the clinic or A&E the same day.

Reading your operation note

Your operation note in four parts. Read the last one first.

Whichever technique was used - microfracture, nanofracture, AMIC - the note the surgeon sends you keeps to the same shape.

A UK consultant knee surgeon reviewing a patient’s operation notes and MRI

A quiet reminder

Surgical language is precise and can read coldly - we translate it for you.

If you would like us to talk you through the note and rehab plan before your review, just ask.

  1. 01 Header

    Joint, defect location and size

    Which joint, which surface (medial femoral condyle, trochlea, patella, talar dome), and the measured size and depth of the defect.

  2. 02 Technique

    Debridement and stimulation

    How the rim was prepared, whether the calcified layer was removed, and the number and pattern of awl or needle perforations.

  3. 03 Findings

    Meniscus, ligaments and alignment notes

    Comments on the meniscus, cruciate ligaments and any incidental findings - plus whether alignment or stability need addressing later.

  4. 04 Impression

    Weight-bearing plan and rehab

    Read this first: touch-toe weeks, CPM hours, progression milestones, return-to-run and return-to-sport windows.

Recognised by major UK insurers

BupaAXA HealthVitalityAvivaWPACignaHealixBupaAXA HealthVitalityAvivaWPACignaHealixBupaAXA HealthVitalityAvivaWPACignaHealix

Cover varies by insurer and by procedure - microfracture and AMIC are usually funded when clinically indicated; MACI approvals are more variable and often need pre-authorisation.

Frequently asked

Everything we get asked about microfracture and cartilage repair.

Quick answers on eligibility, cost, MACI comparison, rehab and honest long-term outcomes.

  • What is microfracture surgery, in one sentence?

    It is an arthroscopic operation that makes tiny holes in the bone under a damaged patch of cartilage so that marrow stem cells can migrate up and form a fibrocartilage repair tissue over the defect.

  • Is microfracture the same as MACI or AMIC?

    No. Microfracture is a single-stage marrow-stimulation technique. AMIC adds a collagen membrane over the microfractured bed. MACI is a two-stage cell-based procedure where your own cartilage cells are grown in a lab and re-implanted. MACI and AMIC generally do better for larger defects - see our knee preservation surgery page.

  • Who is microfracture actually suited to?

    Younger and middle-aged patients (broadly under 45–55) with a symptomatic focal cartilage defect under 2–3 cm², well-shouldered by healthy cartilage, in a stable and reasonably well-aligned joint, with minimal generalised osteoarthritis, and the motivation for a long rehab.

  • When should I not have microfracture?

    If you have widespread osteoarthritis, a defect larger than 3–4 cm², a "kissing lesion" (damage on both sides of the joint), an unstable knee, or significant malalignment. Those cases need MACI, an osteochondral graft, ligament reconstruction, an osteotomy, or in some cases a joint replacement.

  • How much does private microfracture cost in the UK?

    Microfracture typically runs £3,000–£6,000 self-pay, nanofracture £3,500–£6,500, AMIC £5,000–£8,000, and MACI £8,000–£12,000 across the two stages. Insurers usually cover microfracture and often AMIC when clinically indicated.

  • How long is the recovery?

    Expect 6–8 weeks touch-toe or non-weight-bearing on crutches, with 6–8 hours a day of continuous passive motion for the first 6 weeks, then a gradual return to full weight-bearing over 8–12 weeks. No impact activity for 6–9 months and no contact sport for 9–12 months.

  • How well does microfracture hold up long term?

    Honestly: around 60–80% of patients feel better at 2 years, dropping to roughly 60% at 5 years and 40–50% at 10 years. Fibrocartilage does not wear as well as native hyaline cartilage. Younger patients with smaller, non-weight-bearing lesions do best.

  • What can go wrong?

    Incomplete cartilage repair, transient subchondral cysts or bone-marrow oedema, hypertrophic fibrocartilage overgrowth that may need debridement, gradual progression to osteoarthritis, and the usual surgical risks - DVT/PE, infection (under 1%), tourniquet-related issues and, rarely, complex regional pain syndrome. Some patients eventually need MACI, an osteochondral graft or a joint replacement.

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