title: Retroperitoneal lateral lumbar interbody fusion with titanium threaded fusion cages.
abstract: OBJECTIVE
  Intertransverse arthrodesis in which instrumentation is placed is associated with an excellent fusion rate; however, treatment of patients with symptomatic nonunion presents a number of difficulties. Revision posterior and traditional anterior procedures are associated with methodological problems. For example, in the latter, manipulation of the major vessels from L-2 to L-4 may be undesirable. The authors describe a method for performing retroperitoneal lumbar interbody fusion (LIF) in which a threaded cage is placed from L-2 through L-5 via a lateral trajectory, and they also detail a novel technique for implanting a cage from L-5 to S-1 via an oblique trajectory. Although they present data obtained over a 2-year period in the study of 15 patients, the focus of this report is primarily on describing the surgical procedure.
  
  
  METHODS
  The lateral lumbar spine was exposed via a standard retroperitoneal approach. Using the anterior longitudinal ligament as a landmark, the L2-3 through L4-5 levels were fitted with instrumentation via a true lateral trajectory; the L5-S1 level was fitted with instrumentation via an oblique trajectory. A single cage was placed at each instrumented level. Fifteen symptomatic patients in whom previous lumbar fusion had failed underwent retroperitoneal LIF. Thirty-eight levels were fitted with instrumentation. There have been no instrumentation-related failures, and fusion has occurred at 37 levels during the 2-year postoperative period.
  
  
  CONCLUSIONS
  The use of retroperitoneal LIF in which threaded fusion cages are used avoids the technical difficulties associated with repeated posterior procedures. In addition, it allows L2-S1 instrumentation to be placed anteriorly via a single surgical approach. This construct has been shown to be biomechanically sound in animal models, and it appears to be a useful alternative for the management of failed multilevel intertransverse arthrodesis.
authors.affiliation: Department of Neurosurgery, Medical College of Wisconsin and Veterans Affairs Medical Center, Milwaukee 53226, USA.
authors.forename: Christopher E
authors.initials: CE
authors.lastname: Wolfla
authors.forename: Dennis J
authors.initials: DJ
authors.lastname: Maiman
authors.forename: Frank J
authors.initials: FJ
authors.lastname: Coufal
authors.forename: James R
authors.initials: JR
authors.lastname: Wallace
mesh_terms: D000328:Adult; D000368:Aged; D004867:Equipment Design; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000000981:diagnostic imaging / Q000601:surgery; D012086:Reoperation; D012187:Retroperitoneal Space; D012447:Sacrum / Q000000981:diagnostic imaging / Q000601:surgery; D013123:Spinal Fusion / Q000295:instrumentation*; D014025:Titanium; D014057:Tomography, X-Ray Computed
chemical_list: D014025:Titanium