ChondroFiller is an outpatient ultrasound-guided injection—notsurgery—of acellular collagen that recruits the patient's own progenitor cells to regenerate cartilage damage, without upper age or defect-size limits.ChondroFiller is an outpatient ultrasound-guided injection—not surgery—of acellular collagen that recruits the patient's own progenitor cells to regenerate cartilage damage, without upper age or defect-size limits.