It's been called a "medical marvel" in news headlines. Tiger Woods was dealing with back spasms and pain, going through three operations before he underwent an anterior lumbar interbody fusion, a procedure he said gave him his life back. The procedure has been performed for decades but it's considered a last resort.  Carlo Bellabarba, chief of orthopedics at Harborview Medical Center and a UW Medicine spine surgeon, explains the procedure.

"We do it in circumstances when they have an unstable spine for instance, situations where they might have a deformity of the spine, also to stabilize the spine -- and then, of course, if they have a fracture or reasons for instability, he said. "But one of the more controversial reasons that we would do this procedure is for someone who has back pain for what we would call degenerative disc problems."