HE use of LIF for arthrodesis has gained increasing popularity among spine surgeons as evidenced by frequent reports of its use as a treatment for various indications including recurrent herniated disc, spondylolis- thesis, spondylosis, and transitional syndrome. In earlier series investigators reported high rates of clinical success and fusion; 1,5,7 however, these studies have been criticized for their retrospective nature, being authored by the devel- oper(s) of the specific spinal devices used, or lacking the application of standardized outcome criteria. In addition, because uni- or bilateral TLIF is often performed in patients with a history of multiple surgeries and can be technically demanding, the incidence of complications has been significant. 5,10,13 In this prospective series of 42 patients, the authors report the outcomes and complications associated with LIF performed using carbon fiber cages and pedicle screw fixation by a single surgeon. Clinical Material and Methods Patient Population Forty-two consecutive patients were enrolled between February 1999 and July 2000. All patients provided in- formed consent, and the protocol was approved by the Institutional Human Studies Committee. Demographics are summarized in Table 1. A diagnosis of failed fusion was assigned if the posterior LIF was performed to treat a pre- viously fused level; a diagnosis of transitional syndrome was assigned if uni- or bilateral TLIF had been performed to treat a level adjacent to a previous fusion mass that had now become symptomatic. Recurrent disc disease denoted previous discectomy performed at the level now requiring interbody fusion. In patients with DDD, surgery had never been performed at the involved level. In all patients con- servative therapy ( 6 months), consisting mainly of phys- ical therapy, epidural and/or nerve root injections, weight loss, nonopioid analgesic medication, and muscle relaxant agents, had failed to relieve symptoms. Surgical Treatment All surgeries were performed by the senior surgeon J. Neurosurg: Spine / Volume 1 / October, 2004 J Neurosurg (Spine 1) 3:261–266, 2004 Clinical outcomes and complications associated with pedicle screw fixation–augmented lumbar interbody fusion DENNIS J. RIVET , M.D., DAVID JECK, M.D., JAMES BRENNAN, M.D., ADRIAN EPSTEIN, B.A., AND CARL LAURYSSEN, M.D. Department of Neurosurgery and Division of Neuroradiology, Washington University School of Medicine and Barnes-Jewish Hospital, Mallinckrodt Institute of Radiology, St. Louis, Missouri Object. The authors conducted a prospective study to evaluate the clinical and radiological outcomes and compli- cations associated with uni- and bilateral transforaminal lumbar interbody fusion (TLIF) performed using carbon fiber Brantigan I/F Cages and pedicle screw fixation. Methods. Forty-two consecutive patients who had undergone uni- or bilateral TLIF between February 1999 and July 2000 were prospectively evaluated. Clinical outcome was graded using a modified Prolo Scale, the McGill Pain Index Scale, a follow-up questionnaire, and charts. An independent radiologist assessed radiological outcomes. All patients were followed for at least 1 year. Based on Prolo Scale scores, an excellent or good 1-year outcome was achieved in 73% of patients; 90% of patients responded that they would undergo the procedure again. At 1 year, radiographic fusion was demonstrated in 74% and was statistically related to clinical outcome (p  0.05). There were no deaths or major hardware failures. Complications requiring repeated surgery included one case of cerebrospinal fluid (CSF) leakage and one case in which the hemovac drain was retained. There were four cases in- volving minor wound infections, eight involving CSF leaks, and none requiring repeated surgery. On routine follow- up radiography one pedicle screw was found to be broken; the patient remained asymptomatic and fusion occurred. Conclusions. Unilateral and bilateral TLIF involving placement of carbon fiber cages and pedicle screw fixation are effective treatment options in patients with indications for lumbar arthrodesis. The procedures result in acceptable rates of fusion and clinical success, and a minimal incidence of morbidity when performed by an experienced surgeon. KEY WORDS • posterior lumbar interbody fusion • carbon fiber cage • degenerative disc disease • recurrence • pedicle screw T 261 Abbreviations used in this paper: CSF = cerebrospinal fluid; DDD = degenerative disc disease; DSH = disc space height; LIF = lumbar interbody fusion; TLIF = transforaminal LIF.