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Object: There is an increasing awareness of radiation exposure to surgeons and the lifelong implications of such exposure. One of the main criticisms of minimally invasive transforaminal lumbar interbody fusion (MIS TLIF) is the amount of ionizing radiation required to perform the procedure. The goal in this study was to develop a protocol that would minimize the fluoroscopy time and radiation exposure needed to perform an MIS TLIF without compromising visualization of the anatomy or efficiency of the procedure., Methods: A retrospective review of a prospectively collected database was performed to review the development of a low-dose protocol for MIS TLIFs in which a combination of low-dose pulsed fluoroscopy and digital spot images was used. Total fluoroscopy time and radiation dose were reviewed for 50 patients who underwent single-level MIS TLIFs., Results: Fifty patients underwent single-level MIS TLIFs, resulting in the placement of 200 pedicle screws and 57 interbody spacers. There were 28 women and 22 men with an average age of 58.3 years (range 32-78 years). The mean body mass index was 26.2 kg/m(2) (range 17.1-37.6 kg/m(2)). Indications for surgery included spondylolisthesis (32 patients), degenerative disc disease with radiculopathy (12 patients), and recurrent disc herniation (6 patients). Operative levels included 7 at L3-4, 40 at L4-5, and 3 at L5-S1. The mean operative time was 177 minutes (range 139-241 minutes). The mean fluoroscopic time was 18.72 seconds (range 7-29 seconds). The mean radiation dose was 0.247 mGy*m(2) (range 0.06046-0.84054 mGy*m(2)). No revision surgery was required for any of the patients in this series., Conclusions: Altering the fluoroscopic technique to low-dose pulse images or digital spot images can dramatically decrease fluoroscopy times and radiation doses in patients undergoing MIS TLIFs, without compromising image quality, accuracy of pedicle screw placement, or efficiency of the procedure.

Although the efficacy of posterior decompression for symptomatic lumbar stenosis that is recalcitrant to conservative therapy is well proven, uniform agreement on the need for simultaneous arthrodesis is lacking. The variability in the rate of lumbar fusion with and without instrumentation has been attributed to a number of factors: advances in surgical technique; rapid development of instrumentation; radiographic advances in the diagnosis of disease entities of the lumbar spine; evolution in our understanding of bone healing; improved pre- and postoperative care; aggressive rehabilitation; patient compensation; hospital and surgeon reimbursement; better education of residents, fellows, and practicing neurosurgeons; and, most important, the lack of clear indications based on defined diagnostic categories. Based on review of the literature and their experience at the Barrow Neurological Institute, the authors have attempted to define indications for lumbar fusion with or without instrumentation based on defined diagnostic categories. Clear indications for fusion include trauma, tumor, or infection with two- or three-column injury, iatrogenic instability, and isthmic spondylolisthesis. Relative indications for fusion include degenerative spondylolisthesis, radiographically proven dynamic instability with pain or neurological findings, adult scoliosis, and mechanical back pain. Fusion is rarely indicated with discectomy, abnormal radiographs without appropriate findings (such as degenerative disc disease), facet joint syndrome, failed back surgery, or stable spinal stenosis.