Paul W. Detwiler

Lumbar spine interbody fusion with use of synthetic implants

Fusion across a degenerative lumbar disc space has been accomplished by a variety of methods. The traditional approach has been posterior, with or without instrumentation. Recently, interbody fusion has been augmented with bone dowels and synthetic implants that distract the disc space, thereby decompressing the neural foramen and immobilizing the degenerative motion segment. This article reviews the history of interbody fusion and focuses on anterior and posterior interbody fusion using the BAK (Spine-Techn, Inc, Minneapolis, MN) cage. The technique used at our institution for laparoscopic implantation at L4–5 and L5-S1 is described.

Lumbar spine fusion with and without instrumentation

Combining our experience at the Barrow Neurological Institute with a review of the literature, we have defined the indications for fusion of the lumbar spine based on diagnostic categories. Clear indications for fusion include two-or three-column injuries produced by trauma, tumor, or infection; postoperative instability; and isthmic spondylolisthesis. Relative indications include degenerative spondylolisthesis, radiographically proven dynamic instability with pain or neurological findings, adult scoliosis, and mechanical back pain. Fusion is rarely indicated in the setting of routine microdiscectomy; abnormal radiographs without appropriate findings (eg, degenerative disc disease); facet joint syndrome; failed back surgery; or stable spinal stenosis.

Neurophysiological monitoring during surgical treatment of skull-base tumors and vascular lesions

Various electrophysiological monitoring techniques are available for localizing and protecting cranial nerves and the brain stem during skull-base procedures. Separate neural pathways are used with each method, allowing for the simultaneous monitoring of different cranial nerves and brain stem tracts. Although monitoring of the facial nerve during resection of an acoustic neuroma is considered to be a standard of care, other monitoring techniques, such as tracking motor evoked potentials and visual evoked potentials, have not yet gained wide acceptance with neurosurgeons. This situation is in part attributable to technical factors that create difficulties in interpreting intraoperative changes in these responses. The use of individual techniques is usually based on the surgeons level of comfort in attacking a given lesion and in his or her perception of the sensitivity and specificity of each type of electrophysiological monitoring.

Laparoscopic Anterior Lumbar Interbody Fusion

LEARNING OBJECTIVES After reading this article, the practitioner should be able to: Discuss the indications for laparoscopic lumbar interbody fusion. Explain the laparoscopic technique for anterior lumbar interbody fusion. Describe the options available for implant devices.