An ultrasound-guided collagen injection activates the joint's own regenerative cells to repair focalkneecartilage defects; 70–85% of treated patients report meaningful symptom relief within three to five years.An ultrasound-guided collagen injection activates the joint's own regenerative cells to repair focal knee cartilage defects; 70–85% of treated patients report meaningful symptom relief within three to five years.
Defect size is the primary determinant inkneecartilage repair: below 4 cm², autograft transfer from low-load zones is standard; above that threshold, cadaveric allograft removes the biological supply ceiling.Defect size is the primary determinant in knee cartilage repair: below 4 cm², autograft transfer from low-load zones is standard; above that threshold, cadaveric allograft removes the biological supply ceiling.