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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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Is MACI Knee Surgery Worth It?MACI harvests, cultures, and implants the patient's own cartilage cells across two surgeries weeks apart. It delays knee replacement—7.4% progression over a decade—but requires 12–18 months of recovery and works best for younger patients with focal defects of 3 cm² or more.MACI harvests, cultures, and implants the patient's own cartilage cells across two surgeries weeks apart. It delays knee replacement—7.4% progression over a decade—but requires 12–18 months of recovery and works best for younger patients with focal defects of 3 cm² or more.
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Choosing between ACI and MACI for cartilage repairMACI cartilage grafts show 90% fill at two years but decline to 49% by ten years; 73% become fibrocartilage rather than the hyaline cartilage needed for durability.MACI cartilage grafts show 90% fill at two years but decline to 49% by ten years; 73% become fibrocartilage rather than the hyaline cartilage needed for durability.
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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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OCA vs MACI for large knee cartilage defectsMACI (matrix-induced autologous chondrocyte implantation) is a surface repair requiring intact subchondral bone; osteochondral allograft (OCA) replaces both cartilage and bone. When knee cartilage defects breach underlying bone, OCA addresses what MACI cannot.MACI (matrix-induced autologous chondrocyte implantation) is a surface repair requiring intact subchondral bone; osteochondral allograft (OCA) replaces both cartilage and bone. When knee cartilage defects breach underlying bone, OCA addresses what MACI cannot.
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How single-stage ACI differs from MACIMACI repairs cartilage defects over two operations, with weeks between them for external cell expansion; STACi compresses the entire process—harvesting, processing, and implantation—into a single surgical session.MACI repairs cartilage defects over two operations, with weeks between them for external cell expansion; STACi compresses the entire process—harvesting, processing, and implantation—into a single surgical session.
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Single-stage or two-stage cartilage repairCartilage repair decisions hinge on defect size: lesions below roughly 1.5–2 cm² suit single-stage surgery, those of 2–4 cm² permit either approach, and larger defects typically require tissue replacement rather than repair.Cartilage repair decisions hinge on defect size: lesions below roughly 1.5–2 cm² suit single-stage surgery, those of 2–4 cm² permit either approach, and larger defects typically require tissue replacement rather than repair.
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Choosing ACI, MACI or single‑stage cell surgeryACI and MACI are two-stage repairs for localised full-thickness cartilage defects, while single-stage techniques place cells or cell-rich material into the defect in one operation. MACI has the strongest long-term follow-up, but single-stage methods still rest mainly on smaller, less comparable series.ACI and MACI are two-stage repairs for localised full-thickness cartilage defects, while single-stage techniques place cells or cell-rich material into the defect in one operation. MACI has the strongest long-term follow-up, but single-stage methods still rest mainly on smaller, less comparable series.
