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ACI versus MACI for knee cartilage repairCartilage defect size on MRI drives the choice between single-stage repair (AMIC, OATS) and two-stage cell therapy (MACI): below 2–4 cm², simpler alternatives often provide comparable results; at 3 cm² or larger, MACI demonstrates superiority.Cartilage defect size on MRI drives the choice between single-stage repair (AMIC, OATS) and two-stage cell therapy (MACI): below 2–4 cm², simpler alternatives often provide comparable results; at 3 cm² or larger, MACI demonstrates superiority.
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Knee cartilage damage symptoms and who to seeArticular cartilage lacks a blood supply and cannot repair itself; untreated defects larger than 1 cm risk progressive worsening and osteoarthritis.Articular cartilage lacks a blood supply and cannot repair itself; untreated defects larger than 1 cm risk progressive worsening and osteoarthritis.
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Knee Cartilage Repair and PreservationArticular cartilage lacks blood vessels, so when damaged it forms fibrocartilage—a mechanically inferior scar tissue that typically deteriorates within two to three years. This biological constraint shapes every treatment option, from temporary symptom relief to procedures attempting true cartilage regeneration.Articular cartilage lacks blood vessels, so when damaged it forms fibrocartilage—a mechanically inferior scar tissue that typically deteriorates within two to three years. This biological constraint shapes every treatment option, from temporary symptom relief to procedures attempting true cartilage regeneration.
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ACI versus MACI for Knee Cartilage RepairMACI seeds cultured cartilage cells onto a porcine-collagen scaffold fixed with fibrin glue; ACI injects them as liquid suspension sealed with a sutured flap. This mechanical difference determines recovery time, complication risk, and surgical complexity.MACI seeds cultured cartilage cells onto a porcine-collagen scaffold fixed with fibrin glue; ACI injects them as liquid suspension sealed with a sutured flap. This mechanical difference determines recovery time, complication risk, and surgical complexity.
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Knee cartilage damage left untreated and when repair helpsCartilage lacks blood vessels, nerve fibres, and lymph channels, so repair cells cannot reach injuries and pain does not warn of damage, allowing lesions to expand silently until they become clinically serious.Cartilage lacks blood vessels, nerve fibres, and lymph channels, so repair cells cannot reach injuries and pain does not warn of damage, allowing lesions to expand silently until they become clinically serious.
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OATS Mosaicplasty Knee Recovery TimelineFull recovery from OATS mosaicplasty spans 6–12 months, extending to 12–18 months for competitive sport, because transplanted bone-and-cartilage plugs require time for biological integration and graft maturation.Full recovery from OATS mosaicplasty spans 6–12 months, extending to 12–18 months for competitive sport, because transplanted bone-and-cartilage plugs require time for biological integration and graft maturation.
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Who qualifies for MACI knee surgery?for MACI if theirknees are structurally sound—stable ligaments,for MACI if their knees are structurally sound—stable ligaments,
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OATS or MACI for mid-size knee cartilage defectsWithin the 2–4 cm² range, cartilage defects are large enough that a single plug fails to cover them, yet small enough that two repair techniques remain viable: osteochondral autograft restores cartilage and bone in one operation but creates coverage gaps, whilst matrix-induced autologous chondrocyte implantation requires two operations with laboratory…Within the 2–4 cm² range, cartilage defects are large enough that a single plug fails to cover them, yet small enough that two repair techniques remain viable: osteochondral autograft restores cartilage and bone in one operation but creates coverage gaps, whilst matrix-induced autologous chondrocyte implantation requires two operations with laboratory culture but accommodates irregular shapes without gaps.
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Who qualifies for MACI knee surgeryMACI grows hyaline-like cartilage from the patient's own cells and maintains superior pain and function scores at five years, unlike microfracture, whose fibrocartilage typically deteriorates within two to three years.MACI grows hyaline-like cartilage from the patient's own cells and maintains superior pain and function scores at five years, unlike microfracture, whose fibrocartilage typically deteriorates within two to three years.
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ACI or MACI for knee cartilage repairBoth ACI and MACI require two operations: stage-1 biopsy yields too few chondrocytes for immediate repair, so stage-2 implantation must follow 3–6 weeks of laboratory expansion.Both ACI and MACI require two operations: stage-1 biopsy yields too few chondrocytes for immediate repair, so stage-2 implantation must follow 3–6 weeks of laboratory expansion.
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AMIC vs microfracture for knee cartilage repairBoth AMIC and microfracture improve pain and function in the first two years; beyond that point, microfracture outcomes progressively deteriorate whilst AMIC maintains stable gains through a decade of follow-up.Both AMIC and microfracture improve pain and function in the first two years; beyond that point, microfracture outcomes progressively deteriorate whilst AMIC maintains stable gains through a decade of follow-up.
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ACI knee cartilage repair in the UKACI harvests a patient's own cartilage cells, cultures them to roughly 20 times their original number, then implants them in a second operation; NHS funding applies only to patients with defects over 2 cm², no prior cartilage repair, minimal arthritis, and access to a specialist centre.ACI harvests a patient's own cartilage cells, cultures them to roughly 20 times their original number, then implants them in a second operation; NHS funding applies only to patients with defects over 2 cm², no prior cartilage repair, minimal arthritis, and access to a specialist centre.
