Single-stage vs two-stage ACI for cartilage repairTraditional two-stage ACI involves two general anaesthetics separated by a four-to-six-week cell culture period; STACI performs both stages in a single theatre session, requiring one general anaesthetic and eliminating the inter-stage gap.Traditional two-stage ACI involves two general anaesthetics separated by a four-to-six-week cell culture period; STACI performs both stages in a single theatre session, requiring one general anaesthetic and eliminating the inter-stage gap.
When knee cartilage repair is worth consideringCartilage lacks a blood supply and cannot self-heal, but surgical or minimally invasive repair can restore focal defects in otherwise healthy joints, potentially delaying knee replacement by years or decades.Cartilage lacks a blood supply and cannot self-heal, but surgical or minimally invasive repair can restore focal defects in otherwise healthy joints, potentially delaying knee replacement by years or decades.
The cost of leaving a knee cartilage defect untreatedKnee cartilage defects do not heal because cartilage lacks blood supply; defects widen under load with each step, spreading damage to surrounding tissue and progressing towards osteoarthritis if untreated.Knee cartilage defects do not heal because cartilage lacks blood supply; defects widen under load with each step, spreading damage to surrounding tissue and progressing towards osteoarthritis if untreated.
AMIC vs MACI for knee cartilage repairStandalone microfracture for knee cartilage defects has less than 60% survivorship at three years; AMIC adds a collagen membrane to stabilize repair, whilst MACI uses cultured chondrocytes and shows superiority in the SUMMIT trial for lesions over 3 cm².Standalone microfracture for knee cartilage defects has less than 60% survivorship at three years; AMIC adds a collagen membrane to stabilize repair, whilst MACI uses cultured chondrocytes and shows superiority in the SUMMIT trial for lesions over 3 cm².
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.
How defect size and age decide OATS or OCADefect size determines whether focal cartilage repair uses autograft (OATS, harvested from the patient's own knee) or donor allograft (OCA): below 2 cm², autograft is viable; above 4 cm², only allograft remains before arthroplasty.Defect size determines whether focal cartilage repair uses autograft (OATS, harvested from the patient's own knee) or donor allograft (OCA): below 2 cm², autograft is viable; above 4 cm², only allograft remains before arthroplasty.
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.
Who qualifies for OATS knee surgeryOATS transplants hyaline cartilage harvested from a low-load zone of the same knee to repair focal defects. The donor site heals with fibrocartilage, creating potential for catching, locking, or anterior knee pain.OATS transplants hyaline cartilage harvested from a low-load zone of the same knee to repair focal defects. The donor site heals with fibrocartilage, creating potential for catching, locking, or anterior knee pain.
Cartilage Specialist or General Orthopaedic SurgeonFocal cartilage damage—treated with progressive repair techniques from injections to cell-based therapy—warrants a cartilage specialist. Widespread arthritis, fractures, or joint replacement require a general orthopaedic surgeon. Damage type and location, not pain severity, determine which specialist is appropriate.Focal cartilage damage—treated with progressive repair techniques from injections to cell-based therapy—warrants a cartilage specialist. Widespread arthritis, fractures, or joint replacement require a general orthopaedic surgeon. Damage type and location, not pain severity, determine which specialist is appropriate.
When cartilage repair makes sense before knee replacementTotal knee replacement achieves over 90% long-term success, yet patients under 55 face substantially higher revision risk within 20 years. For focal cartilage damage in the mid-40s, repair offers a joint-preservation pathway suited to this earlier disease stage—provided defect size and patient profile meet defined clinical criteria.Total knee replacement achieves over 90% long-term success, yet patients under 55 face substantially higher revision risk within 20 years. For focal cartilage damage in the mid-40s, repair offers a joint-preservation pathway suited to this earlier disease stage—provided defect size and patient profile meet defined clinical criteria.
OCA or MACI for large knee cartilage defectsWhen subchondral bone is damaged alongside large knee cartilage defects, OCA — a single-stage transplant of donor bone and cartilage — is the preferred choice; MACI, which implants cultured cells, cannot restore bone stock once lost.When subchondral bone is damaged alongside large knee cartilage defects, OCA — a single-stage transplant of donor bone and cartilage — is the preferred choice; MACI, which implants cultured cells, cannot restore bone stock once lost.
MACI versus microfracture for knee cartilage repairMACI outperforms microfracture for knee cartilage defects of 3 cm² or larger, according to the SUMMIT randomised trial, which found significantly greater improvements in pain and function at two years that persisted through five years.MACI outperforms microfracture for knee cartilage defects of 3 cm² or larger, according to the SUMMIT randomised trial, which found significantly greater improvements in pain and function at two years that persisted through five years.