Chemonucleolysis is a non-surgical treatment for a bulging disc that involves the injection of an enzyme into the vertebral disc with the goal of dissolving the inner part of the disc, the nucleus pulposus.
The procedure uses chymopapain, an enzyme from the papaya fruit, to dissolve the displaced disc material that is putting pressure on the spinal nerve.
The theory is that if chemonucleolysis can successfully alleviate back pain from a bulging disc, it could prevent the need for invasive surgery such as a spinal fusion.
The technique is controversial because the efficacy of the treatment is unproven and complications such as paraplegia, subarachnoid hemorrhaging, and adverse reactions to the papaya content of chymopapain may occur.
In the United States, chemonucleolysis has been approved only for use in the lumbar spine. Because of the legal liability from previous complications associated with the procedure, it is largely no longer available in the U.S.