Segmental ("floating") lumbar spine fusions.

A traditional teaching in orthopaedic surgery has been that, in cases of fusion for L4-5 discopathy or instability, one must include the lumbosacral joint. There is nothing in the literature to support this time-honored dictum. The senior author, among others, has rejected this concept; and, the authors are, therefore, in a position to present a 32-year experience with segmental or "floating" fusion. Two hundred six floating fusions were performed, of which 184 were available for follow-up. Of these, 83.7% achieved "Excellent" or "Good" results; 15.2% were rated "Fair"; and 2% were rated "Poor." Only five patients (2.7%) had subsequent disc herniation at the lumbosacral level necessitating discectomy and extension of fusion to incorporate the sacrum.