Meniscofluoresis: an aid in determining prognosis of meniscal tears1
Until recently, it was believed that tears of knee menisci were incapable of healing. However, experimental and clinical evidence has now confirmed that some meniscal tears can be surgically repaired, particularly those around the periphery of the meniscus. Blood vessels penetrate that peripheral rim to a variable depth, from 10% to 25% of the meniscal substance. Although this blood supply is thought to be related to healing potential, it is difficult to determine clinically the extent of vascularization. Fluorescein is a relatively nontoxic dye long used in determining viability of skin flaps. When injected into the vascular system, it fluoresces under exposure to ultraviolet light. This is a highly consistent and accurate predictor of vascular integrity and tissue viability. We found that fluorescein dye can penetrate the vascular portion of the dog meniscus and fluoresce under exposure to ultraviolet light. Meniscal tears surgically created in the fluorescent portion of the meniscus healed, whereas those in the nonfluorescent portion did not. Intravenous use of fluorescein dye may be a safe and efficacious method of determining which meniscal tears might best be managed by repair rather than excision.