19-82 years) and the mean age for WC patients was 46.5 years (range: 29-70 years). OUTCOME MEASURES: Patients completed a presurgical screening evaluation, including an interview with a psychologist, completing psycho- logical questionnaires, as well as the MMPI-2-RF before spine surgery. METHODS: Patient who were referred for presurgical psychosocial screening completed questions and a structured interview. Data from these evaluations were compared for WC vs. Non-WC patients to determine if there were identifiable differences between these groups. RESULTS: Educational level differed significantly in the two groups with college completed by 35.7% of Non-WC vs. 8.3% of WC patients. Only 1.6% of Non-WC patients did not graduate from high school vs. 13.9% of WC patients. Pre-operatively, WC patients displayed relatively elevated sensitivity to symptoms reflected by higher scores on gastrointestinal prob- lems, head pain, as well as neurological and cognitive complaint scales. WC patients’ MMPI-2-RF profiles displayed a greater sense of inefficacy, more behavior-restricting fears, more aggression, and a higher level of ab- errant experiences. WC patients also reflected a greater sense of entitle- ment and demoralization. WC patients were not more fearful, worried, or depressed than Non-WC patients. CONCLUSIONS: Psychological factors have been reported to be related to surgical outcome. Compromised surgical outcomes in WC patients may be related to personality/behavioral factors that are more prominent in this population. This study found that WC patients had a lower level of educa- tion and had different personality profiles with respect to emotion, self-im- age, pain sensitivity and reported more physical complaints compared with Non-WC patients. Further investigation is underway to determine to what extent these factors contribute to the differences in surgical outcome. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs. http://dx.doi.org/10.1016/j.spinee.2012.08.107 67. Assessment of the Prevalence and Severity of Insomnia in a Chronic Disabling Occupational Spinal Disorder Population: An Underemphasized Symptom Sali R. Asih, PhD 1 , Randy Neblett 2 , Emily Brede, RN, BSN 1 , Robert J. Gatchel, PhD 3 , Tom G. Mayer, MD 4 ; 1 Arlington, TX, US; 2 PRIDE Research Foundation, Dallas, TX, US; 3 University of Texas Department of Psychology, Arlington, TX, US; 4 PRIDE, Dallas, TX, US BACKGROUND CONTEXT: Insomnia is frequently experienced by pa- tients suffering from chronic spinal pain, but is often seen as simply a gen- eral symptom accompanying pain or depression. Compared to those who experience insomnia only, patients with both chronic pain and insomnia have more impaired cognitive function, greater mood lability, fatigue and daytime sleepiness. Researchers have studied the relationship between insomnia and chronic pain conditions in specific populations, such as ar- thritis, fibromyalgia, and migraine headache. To date, however, insomnia has not been studied in a chronic disabling occupational spinal disorder (CDOSD) population. PURPOSE: To quantify the prevalence and severity of self-reported in- somnia in a CDOSD population, and to determine its relationship to self-reported pain, depressive symptoms, and perceived disability. STUDY DESIGN/SETTING: Prospective cohort study. PATIENT SAMPLE: A consecutive sample of 174 patients who entered an interdisciplinary functional restoration program at a regional referral center. OUTCOME MEASURES: Insomnia was assessed with the Insomnia Se- verity Index (ISI), a self-report measure of insomnia symptoms. Using es- tablished cut-off levels, 2 patient groups were formed: those with Clinical Insomnia (CI5moderate to severe symptoms); and those with Non-Clini- cal Insomnia (NCI5None to sub-threshold symptoms). In addition, 3 patterns of sleep disturbance were evaluated: early; middle and late clinical insomnia. Psychosocial self-report data included the Pain Intensity Visual Analog Scale (PVAS), the Beck Depression Inventory (BDI), and the Pain Disability Questionnaire (PDQ). METHODS: The prevalence of sleep disturbance patterns and the psycho- social effects were determined with independent chi-square tests. The shared variances of clinical insomnia, depression, and pain were deter- mined by regression analysis. RESULTS: The presence of CI was found in 69.5% of the CDOSD cohort. Compared with NCI, CI was associated with severe (PVAS O7) pain inten- sity (OR52.7, p !.01), severe (PDQ O 100) perceived disability (OR54.6, p !.01) and extreme (BDI O29) depressive symptoms (OR515.3, p !.01). In terms of sleep disturbance patterns, a combined pattern of early, middle and late CI was reported by 40% of patients, while 36% reported only 2 disturbances, and 24% of patients reported a single pattern of CI. Although correlations were found, the shared variance between CI and depressive symptoms was only 23%, and shared variance between CI and pain was only 10%. These data indicate that clinical insomnia is a construct inde- pendent of pain, and even relatively separate from the construct of depression. CONCLUSIONS: Nearly 70% of CDOSD patients met criteria for CI, suggesting that this is a significant and pervasive problem. Over 75% of patients also reported having combined early, middle and/or late CI. Thus, although CI is often assumed to be simply a component of pain or depres- sion, these findings show that a significant portion of the variance is inde- pendent of the Pain or Depression constructs. The study suggests that CI should be evaluated and treated as an independent symptom, with appro- priate pharmacological and biopsychosocial interventions when needed. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs. http://dx.doi.org/10.1016/j.spinee.2012.08.108 Thursday, October 25, 2012 11:00 AM – 12:00 PM Concurrent Session: Imaging 68. Preoperative Facet Fluid Correlates with Cranial Adjacent Segment Instability Following Posterior Lumbar Interbody Fusion: A Minimum Two-Year Follow-Up Chikara Ushiku 1 , Shigeru Soshi, MD 1 , Yoshikuni Kida, MD 1 , Kurando Hashimoto, MD 2 ; 1 The Jikei University of School of Medicine, Tokyo, Japan; 2 Toda, Japan BACKGROUND CONTEXT: Spinal fusion often causes complications in adjacent segments. There is a possibility that lumbar facet fluid (FF) de- tected on MRI may indicate instability, even if the instability is not mea- surable on decubitus flexion/extension films. Although FF is occasionally observed pre-operatively at cranial adjacent segments, it is not known whether a pre-existence of FF would affect postoperative instability fol- lowing fusion lumbar spine surgery. PURPOSE: The purpose of this study was to analyze a possible associa- tion between pre-operative FF (Pre-FF) and postoperative instability at the cranially adjacent segment after posterior lumbar interbody fusion (PLIF). STUDY DESIGN/SETTING: A retrospective study. PATIENT SAMPLE: Thirty-eight patients who underwent a single level PLIF at L4/5 for degenerative spondylolisthesis were enrolled, and the minimum follow-up period was 2 years. The PLIF procedure was the same and bony union was successfully obtained in all patients. OUTCOME MEASURES: All parameters were measured at the level L3/ 4. ROM, translation and disc height were measured both pre-operatively 34S Proceedings of the NASS 27th Annual Meeting / The Spine Journal 12 (2012) 22S–44S All referenced figures and tables will be available at the Annual Meeting and will be included with the post-meeting online content.