Key Role of Preoperative Recumbent Films in the Treatment of Severe Sagittal Malalignment.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To determine if severe sagittal malalignment (SM) patients without fixed deformities require a three-column osteotomy (3CO) to achieve favorable clinical and radiographic outcomes. SUMMARY OF BACKGROUND DATA: 3CO performed for severe SM has significantly increased in the last 15 years. Not all severe SM patients require a 3CO. METHODS: Severe SM patients (sagittal vertical axis [SVA] >10 cm) who underwent deformity correction between 2002 and 2011. Patients with <33% change in their lumbar lordosis (LL) on a preoperative supine radiograph were classified as stiff deformities, whereas those with ≥33% change were categorized as flexible deformities. The clinical/radiographic outcomes were assessed at minimum two years postoperatively. RESULTS: Seventy patients met the inclusion criteria, 35 patients with flexible and 35 with stiff deformities. Eighteen flexible-deformity patients underwent a 3CO versus 22 stiff-deformity patients. The remaining patients in each group underwent spinal realignment without a 3CO. The flexible-deformity patients not undergoing a 3CO had overall improvement in all sagittal radiographic parameters. Preoperative LL (22°), LL-pelvic incidence (PI) mismatch (43), SVA (17 cm), and pelvic tilt (PT, 34°) improved to 46°, 18, 6 cm, and 26°, respectively, p < .05. Flexible-deformity patients who underwent a 3CO also had overall improvement in all radiographic parameters. Preoperative LL (8.5°), LL-PI mismatch (47), SVA (19 cm), and PT (37°) improved to 39°, 15, 7 cm, and 24°, respectively (p < .05). Stiff-deformity patients who underwent a 3CO had statistically significant improvement in all radiographic parameters. However, stiff-deformity patients who did not undergo a 3CO had suboptimal improvement in all radiographic parameters, except for SVA (14 cm-9 cm, p < .05). Flexible patients who did not undergo a 3CO had statistical improvement in the SRS domains of function and self-mage as well as in their ODI scores (p < .05). CONCLUSION: Severe SM that is flexible can be corrected without a 3CO without compromising clinical and radiographic outcomes. LEVEL OF EVIDENCE: Level III.

Decompression in Adult Lumbar Deformity Surgery Is Associated With Increased Perioperative Complications but Favorable Long-Term Outcomes.

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: To analyze the impact of performing a formal decompression in patients with adult lumbar scoliosis with symptomatic spinal stenosis on perioperative complications and long-term outcomes. METHODS: Adult patients undergoing at least 5 levels of fusion to the sacrum with iliac fixation from 2002 to 2008 who had a minimum 5-year follow-up at one institution were studied. Patients who had 3-column osteotomy were excluded from the study. Perioperative complications and clinical outcomes (Scoliosis Research Society [SRS], Oswestry Disability Index [ODI], and Numerical Rating Scale [NRS] back/leg pain) were analyzed. Patients who underwent formal laminectomy/decompressions were compared with those who did not. Differences between the 2 groups were analyzed using Student's t test. RESULTS: A total of 147 patients were included in the study (Decompression: n = 55 [37%], No decompression: n = 92 [63%]). Average fusion levels for the decompression and no decompression groups were 11 and 12 levels, respectively (P = .26). Mean improvements in SRS domains for decompression versus no decompression patients, respectively, were pain (1.1 vs 0.9, P = .3), function (0.7 vs 0.5, P = .09), self-image (1.1 vs 1.1, P = .9), and mental health (0.5 vs 0.4, P = .5). Furthermore, additional mean improvements were ODI (21 vs 21, P = .14), NRS-Back pain (3.0 vs 1.3, P = .16), and NRS-Leg pain (3.9 vs 0.5, P = .002). Complication rates between the decompression group and no decompression group differed in incidental durotomies (18.2% vs 0%) and cardiac-related (9.1% vs 1.1%). CONCLUSIONS: Performing a formal decompression in adult lumbar scoliosis with symptomatic spinal stenosis is associated with increased perioperative complications but favorable long-term clinical outcomes.

Intradural extramedullary cavernous malformation with extensive superficial siderosis of the neuraxis: Case report and review of literature.

BACKGROUND: Spinal cavernous malformations usually affect the vertebral bodies and are seldom intradural. Here, we report a rare spinal intradural-extramedullary cavernous malformation associated with extensive superficial siderosis along the neuraxis in a patient with radicular complaints. CASE DESCRIPTION: A 60-year-old male presented with subacute headaches, intermittent fever, and acute back and radicular leg pain for 1-2 weeks. Magnetic resonance imaging revealed an intradural-extramedullary lesion just below the conus medullaris (at the L2 level). There was associated subarachnoid hemorrhage in the lumbar cistern and superficial siderosis along the entire spinal neuraxis. Following surgical resection, the patient's symptoms resolved. Histopathology of the lesion was of a cavernous malformation. CONCLUSIONS: There are only 56 cases of spinal intradural-extramedullary cavernous malformations published in the literature; however, only 3 described superficial neuraxis siderosis as noted in this case. In the present case, slowly recurring hemorrhages of the lesion located at the conus likely contributed to the complete neuraxis superficial siderosis. Timely evaluation and treatment of these lesions is warranted to avoid further compressive and/or hemorrhagic complications.

Use of Bivector Traction for Stabilization of the Head and Maintenance of Optimal Cervical Alignment in Posterior Cervical Fusions.

STUDY DESIGN: Retrospective analysis of consecutive case series. OBJECTIVE: To introduce a novel method of stabilizing the cranium using bivector traction in posterior cervical fusions. METHODS: A retrospective review of 50 consecutive patients undergoing instrumented posterior cervical arthrodesis was performed. All patients had at least 3 levels of subaxial fusion using the bivector traction apparatus. Patients' demographic data was recorded for the following: pre- and postoperative cervical lordosis, pre- and postoperative cervical sagittal vertical alignment (cSVA), and intraoperative complications from pin placements. RESULTS: A total of 50 patients were studied. There were 31 females and 19 males. The mean age at the time of surgery was 49 years (range 35-79). A mean 5.8 levels were fused. The most common levels fused were C2-T3 in 14 patients followed by C2-T2 in 7 patients. In no case did the surgeon or assistant have to scrub out to adjust the alignment. The mean pre- and postoperative cervical lordosis was -6.0° and -10°, respectively (P = .04). The mean pre-and postoperative cSVA was 30.5 mm and 32 mm, respectively (P = .6). There were no complications related to placement of the Gardner-Well tongs. CONCLUSION: The bivector traction is an easy, safe, and effective method of stabilizing the head and obtaining adequate cervical sagittal alignment.

Does Planned Staging for Posterior-Only Vertebral Column Resections in Spinal Deformity Surgery Increase Perioperative Complications?

STUDY DESIGN: Propensity-matched case control. OBJECTIVES: To compare the perioperative complication rate between single- and two-stage posterior-only VCRs (2-pVCR). SUMMARY OF BACKGROUND DATA: A vertebral column resection (VCR) for severe spinal deformity is a technically challenging and lengthy procedure with a potentially high complication rate. Planned staging has an advantage of distributing operative time into 2 smaller, more manageable, intervals. METHODS: Adult and pediatric spinal deformity patients undergoing a VCR were retrospectively identified from a single institution's surgical database from 1985 to 2013. Propensity scoring was used to match 2-pVCR and single-staged patients. Each group was matched for 15 preoperative risk factors including demographic, operative, and radiographic characteristics. Perioperative complications were defined as occurring within 2 months of initial surgery. Additionally, a binary logistic regression analysis was performed with complications as the outcome. RESULTS: A total of 183 consecutive patients were identified as undergoing a VCR, with 172 meeting the inclusion criteria (posterior-only). Forty-four patients underwent planned 2-pVCR whereas 124 had a single-staged VCR. Consistent with propensity-matching, no statistically significant difference between the single- and 2-pVCR cohorts existed for all matching parameters, except pulmonary function tests. There was no significant difference (p = .290) between complication rates for single-stage (12/35; 34%) and 2-pVCR (8/35; 23%) patients. Stepwise binary logistic regression analysis showed that age (p = .014; OR = 0.94, CI = 0.89-0.99) and body mass index (p = .030; OR = 1.13 CI = 1.01-1.26) influenced the occurrence of a complication. CONCLUSION: Planned staging of posterior-only VCRs does not increase the occurrence of perioperative complications in adult and pediatric spinal deformity patients. LEVEL OF EVIDENCE: III (Propensity-matched case control).

Factors associated with spinal fusion after posterior fossa decompression in pediatric patients with Chiari I malformation and scoliosis.

OBJECTIVE The authors performed a study to identify clinical characteristics of pediatric patients diagnosed with Chiari I malformation and scoliosis associated with a need for spinal fusion after posterior fossa decompression when managing the scoliotic curve. METHODS The authors conducted a multicenter retrospective review of 44 patients, aged 18 years or younger, diagnosed with Chiari I malformation and scoliosis who underwent posterior fossa decompression from 2000 to 2010. The outcome of interest was the need for spinal fusion after decompression. RESULTS Overall, 18 patients (40%) underwent posterior fossa decompression alone, and 26 patients (60%) required a spinal fusion after the decompression. The mean Cobb angle at presentation and the proportion of patients with curves > 35° differed between the decompression-only and fusion cohorts (30.7° ± 11.8° vs 52.1° ± 26.3°, p = 0.002; 5 of 18 vs 17 of 26, p = 0.031). An odds ratio of 1.0625 favoring a need for fusion was established for each 1° of increase in Cobb angle (p = 0.012, OR 1.0625, 95% CI 1.0135-1.1138). Among the 14 patients older than 10 years of age with a primary Cobb angle exceeding 35°, 13 (93%) ultimately required fusion. Patients with at least 1 year of follow-up whose curves progressed more 10° after decompression were younger than those without curve progression (6.1 ± 3.0 years vs 13.7 ± 3.2 years, p = 0.001, Mann-Whitney U-test). Left apical thoracic curves constituted a higher proportion of curves in the decompression-only group (8 of 16 vs 1 of 21, p = 0.002). CONCLUSIONS The need for fusion after posterior fossa decompression reflected the curve severity at clinical presentation. Patients presenting with curves measuring > 35°, as well as those greater than 10 years of age, may be at greater risk for requiring fusion after posterior fossa decompression, while patients less than 10 years of age may require routine monitoring for curve progression. Left apical thoracic curves may have a better response to Chiari malformation decompression.

Spinal Implant Density and Postoperative Lumbar Lordosis as Predictors for the Development of Proximal Junctional Kyphosis in Adult Spinal Deformity.

OBJECTIVE: To evaluate spinal implant density and proximal junctional kyphosis (PJK) in adult spinal deformity (ASD). METHODS: Consecutive patients with ASD receiving ≥5 level fusions were retrospectively analyzed between 2007 and 2010. INCLUSION CRITERIA: ASD, elective fusions, minimum 2-year follow-up. EXCLUSION CRITERIA: age <18 years, neuromuscular or congenital scoliosis, cervical or cervicothoracic fusions, nonelective conditions (infection, tumor, trauma). Instrumented fusions were classified by the Scoliosis Research Society-Schwab ASD classification. Statistical analysis consisted of descriptives (measures of central tendency, dispersion, frequencies), independent Student t tests, χ2, analysis of variance, and logistic regression to determine association of implant density [(number of screws + number of hooks)/surgical levels of fusion] and PJK. Mean and median follow-up was 2.8 and 2.7 years, respectively. RESULTS: Eighty-three patients (17 male, 66 female) with a mean age of 59.7 years (standard deviation, 10.3) were analyzed. Mean body mass index (BMI) was 29.5 kg/m2 (range, 18-56 kg/m2) with mean preoperative Oswestry Disability Index of 48.67 (range, 6-86) and mean preoperative sagittal vertical axis of 8.42. The mean levels fused were 9.95 where 54 surgeries had interbody fusion. PJK prevalence was 21.7%, and pseudoarthrosis was 19.3%. Mean postoperative Oswestry Disability Index was 27.4 (range, 0-74). Independent Student t tests showed that PJK was not significant for age, gender, BMI, rod type, mean postoperative sagittal vertical axis, or Scoliosis Research Society-Schwab ASD classification; but iliac fixation approached significance (P = 0.077). Implant density and postoperative lumbar lordosis (LL) were predictors for PJK (P = 0.018 and 0.045, respectively). Controlling for age, BMI, and gender, postoperative LL (not implant density) continued to show significance in multivariate logistic regression model. CONCLUSIONS: PJK, although influenced by a multitude of factors, may be statistically related to implant density and LL.

Cranial Center of Mass Compared to C7 Plumb Line Alignment in Adult Spinal Deformity.

OBJECTIVE: To report the cranial center of mass (CCOM) progression in surgically treated patients for adult spinal deformity (ASD). The C7 plumb line/sagittal vertical axis (SVA) has important relationships with patient-reported outcomes; however, this has not yet been defined for CCOM. METHODS: Patients with consecutive ASD who were undergoing surgery greater than 5 levels of fusion between 2007 and 2012 and had radiographic, clinical, and outcomes data spanning ≥2 years were analyzed, retrospectively. Radiographic parameters were obtained preoperatively and at 6 weeks, 1 year, and 2 years postoperatively. Statistical analysis included descriptives (measures of central tendency, dispersion, frequencies), independent Student t tests, χ(2) square, Pearson correlation, and Kaplan-Meyer curve. RESULTS: Fifty-eight patients (10 male, 48 female) with a mean age of 60.5 years (range, 27-81 years) were reviewed. The mean preoperative SVA was 7.40 cm (SD = 5.51; 37/58 [63.8%] malalignment), and mean CCOM was 10.0 cm (SD = 6.58; 47/58 [81%] malalignment). Six-week postoperative SVA and CCOM was -0.17 cm (SD = 3.3) and 2.5 cm (SD = 4.11), respectively. SVA malalignment was 12.7% and CCOM malalignment was 38.2% at 6 weeks postop. Six week (absolute), 6-week change, and patient number at 6 weeks who were CCOM malaligned was significant compared with SVA (P = 0.003, P < 0.001, P < 0.001, respectively). SRS appearance worsened as preoperative SVA and CCOM increased (P < 0.05), and 2-year SRS appearance and mental health was worsened as 2-year SVA and CCOM increased (P < 0.05). SVA malalignment was 8 and 10 at 1 and 2 years, respectively, and CCOM malalignment was 24 and 32, respectively. Kaplan-Meier curve demonstrates persistent malalignment of CCOM at 6 weeks if not corrected. CONCLUSION: CCOM alignment restoration is an important parameter in ASD, and malalignment is consistent over time.

Adult Degenerative Scoliosis.

The treatment of adult degenerative scoliosis begins in the outpatient setting when evaluating a patient both radiographically. Assessing the flexibility of the deformity is essential in determining what techniques will be required to achieve the goals of correction. Ultimately the surgeon's comfort and experience and the patient's medical risk stratification determine the strategy needed to address either a focal pathology or ultimate deformity correction.

Cost minimization in treatment of adult degenerative scoliosis.

OBJECT: Back pain is an increasing concern for the aging population. This study aims to evaluate if minimally invasive surgery presents cost-minimization benefits compared with open surgery in treating adult degenerative scoliosis. METHODS: Seventy-one patients with adult degenerative scoliosis received 2-stage, multilevel surgical correction through either a minimally invasive spine surgery (MIS) approach with posterior instrumentation (n = 38) or an open midline (Open) approach (n = 33). Costs were derived from hospital and rehabilitation charges. Length of stay, blood loss, and radiographic outcomes were obtained from electronic medical records. Functional outcomes were measured with Oswestry Disability Index (ODI) and visual analog scale (VAS) surveys. RESULTS: Patients in both cohorts were similar in age (Age(MIS) = 65.68 yrs, Age(Open) = 63.58 yrs, p = 0.28). The mean follow-up was 18.16 months and 21.82 months for the MIS and Open cohorts, respectively (p = 0.34). MIS and Open cohorts had an average of 4.37 and 7.61 levels of fusion, respectively (p < 0.01). Total inpatient charges were lower for the MIS cohort ($269,807 vs $391,889, p < 0.01), and outpatient rehabilitation charges were similar ($41,072 vs $49,272, p = 0.48). MIS patients experienced reduced length of hospital stay (7.03 days vs 14.88 days, p < 0.01) and estimated blood loss (EBL) (EBL(MIS) = 470.26 ml, EBL(Open)= 2872.73 ml, p < 0.01). Baseline ODI scores were lower in the MIS cohort (40.03 vs 48.04, p = 0.03), and the cohorts experienced similar 1-year improvement (ΔODI(MIS) = -15.98, ΔODI(Open) = -21.96, p = 0.25). Baseline VAS scores were similar (VAS(MIS) = 6.56, VAS(Open)= 7.10, p = 0.32), but MIS patients experienced less reduction after 1 year (ΔVAS(MIS) = -3.36, ΔVAS(Open) = -4.73, p = 0.04). Preoperative sagittal vertical axis (SVA) were comparable (preoperative SVA(MIS) = 63.47 mm, preoperative SVA(Open) = 71.3 mm, p = 0.60), but MIS patients had larger postoperative SVA (postoperative SVA(MIS) = 51.17 mm, postoperative SVA(Open) = 28.17 mm, p = 0.03). CONCLUSIONS: Minimally invasive surgery demonstrated reduced costs, blood loss, and hospital stays, whereas open surgery exhibited greater improvement in VAS scores, deformity correction, and sagittal balance. Additional studies with more patients and longer follow-up will determine if MIS provides cost-minimization opportunities for treatment of adult degenerative scoliosis.

SRS22R Appearance Domain Correlates Most With Patient Satisfaction After Adult Deformity Surgery to the Sacrum at 5-year Follow-up.

STUDY DESIGN: Longitudinal cohort. OBJECTIVE: To evaluate the relationship between Scoliosis Research Society-22R (SRS22-R) domains and satisfaction with management in patients who underwent surgical correction for adult spine deformity. SUMMARY OF BACKGROUND DATA: The SRS-22R is used to measure clinical outcomes in adult spine deformity patients. The relationship between patient satisfaction and SRS-22R domain scores, the Oswestry Disability Index (ODI) and radiographical parameters has not been reported at 5-year follow-up. METHODS: 135 patients with adult spinal deformity at a single institution who underwent a posterior spinal fusion of 5 levels or more to the sacrum and had complete SRS-22R pre- and minimum 5-year postoperative were identified. Wilcoxon tests were used to compare preoperative and 5-year postoperative scores. Spearman correlations were used to evaluate associations between the 5-year SRS-22R Satisfaction score and changes in SRS-22R domain scores, SubScore (SRS-22R Total-Satisfaction), ODI, and radiographical parameters. RESULTS: There were 125 females and 10 males with a mean BMI of 26.6 kg/m and mean age of 53.6 years. There were 74 primary and 61 revision surgeries with a mean 9.9 levels fused and mean follow-up of 67 months. There was a statistically significant improvement between paired pre- and 5-year postop SRS-22R domain scores and most radiographical parameters, commonly P ≤ 0.001. The majority of patients had an SRS-22R Satisfaction score of 3.0 or more (88%) or 4.0 or more (67%), consistent with a moderate ceiling effect. Correlations for SRS-22R domain scores were all statistically significant and either weak [Mental (0.26), Activity (0.27), Pain (0.35), or moderate (Appearance (0.59))]. SRS-22R SubScore (0.54) and ODI (0.43) also had a moderate correlation. Correlations for all radiographical and operative parameters were either very weak or weak. CONCLUSION: SRS-22R Appearance, SubScore, and ODI correlate most with patient satisfaction in adult deformity patients undergoing 5 or more level fusion to the sacrum at 5-year follow-up. LEVEL OF EVIDENCE: 2.

Time to Event Analysis for the Development of Venous Thromboembolism After Spinal Fusion ≥ 5 Levels.

OBJECTIVE: Venous thromboembolism (VTE) is an important complication after spine surgery with an incidence of 31%. To our knowledge, no study has reported a time-dependent examination of factors influencing VTE. We report factors influencing first and multiple VTE events and perform a time-dependent analysis. METHODS: A retrospective analysis was performed of consecutive, "high-risk" patients receiving multilevel spinal fusion and an inferior vena cava (IVC) filter during the period 2000-2008. Descriptive statistics and frequencies were examined. Student t tests and logistic regression analysis identified confounders influencing development of acute VTE. Kaplan-Meier survival and Cox proportional hazard model evaluated time-dependent risk factors. Multivariate linear regression model analyzed multiple acute VTE events. RESULTS: There were 218 patients (149 women and 69 men) with an average age of 59.2 years (range, 18-86 years) who had 252 hospitalizations with an average stay of 20.3 days (SD = 15.6). There were 72 VTE events, with mean time to VTE of 15 days (SD = 18.1). Logistic regression identified factors influencing development of acute VTE, including sex (P = 0.04, OR = 0.243), VTE history (P = 0.001, OR = 8.0), IVC filter type (P = 0.050, OR = 15.6), chemoprophylaxis (P = 0.013, OR = 0.82), and hospital stay (P < 0.001, OR = 0.16). Kaplan-Meier curve revealed VTE history increased the rate of VTE development (P = 0.003). Cox proportional hazard model demonstrated IVC filter type (P = 0.003, hazard ratio = 5.042) and VTE history (P = 0.001, hazard ratio = 4.187) were significant for first VTE events. Linear regression analysis identified factors influencing development of multiple VTE events during a hospitalization, including VTE history (P < 0.01), chemoprophylaxis (P = 0.003), IVC filter type (P = 0.015), and hospital stay (P < 0.001). Mean and median follow-up were 3.3 years and 2.8 years, respectively. CONCLUSIONS: Sex, VTE history, IVC filter type, chemoprophylaxis, and hospital stay influenced development of VTE. Time to VTE correlated with DVT history and IVC filter type, whereas VTE history and hospital stay influenced multiple VTE events.

Thoracic spinal cord intramedullary aspergillus invasion and abscess.

Invasive central nervous system aspergillosis is a rare form of fungal infection that presents most commonly in immunocompromised individuals. There have been multiple previous reports of aspergillus vertebral osteomyelitis and spinal epidural aspergillus abscess; however to our knowledge there are no reports of intramedullary aspergillus infection. We present a 19-year-old woman with active acute lymphoblastic leukemia who presented with several weeks of fevers and bilateral lower extremity weakness. She was found to have an intramedullary aspergillus abscess at T12-L1 resulting from adjacent vertebral osteomyelitis and underwent surgical debridement with ultra-sound guided aspiration and aggressive intravenous voriconazole therapy. To our knowledge this is the first reported case of spinal aspergillosis invading the intramedullary cavity. Though rare, this entity should be included in the differential for immunocompromised patients presenting with fevers and neurologic deficit. Early recognition with aggressive neurosurgical intervention and antifungal therapy may improve outcomes in future cases.

Development and validation of a generalizable model for predicting major transfusion during spine fusion surgery.

BACKGROUND: Surgery for posterior spine instrumentation often requires major transfusion. The aim of this study was to develop and test the validity of a model for predicting intraoperative major transfusion (>4 U total red blood cells), based on preoperative patient and surgical variables, that was applicable to adult patients undergoing cervical, thoracic, and/or lumbar spine deformity surgery with and without osteotomies. MATERIALS AND METHODS: The perioperative data from 548 patients who underwent ≥ 3 levels of posterior spinal fusion with instrumentation between January 1, 2003 and May 30, 2009, were retrospectively collected to create a model for predicting major blood transfusion. The validity of the model was retrospectively tested with a separate data set of 95 patients who underwent surgery from June 1, 2009 through September 30, 2010. RESULTS: There was a 59.5% incidence of major transfusion in the derivation set of patients. Independent predictors of major transfusion were operation duration, number of posterior levels instrumented, surgical complexity score, and preincision hemoglobin. This model was able to predict major transfusion significantly better than a previously published model (ROCAUC=0.89; 99% confidence interval, 0.80-0.90; P<0.001). CONCLUSIONS: Our model has an increased accuracy for predicting the probability of major transfusion compared with a previously published model. In addition, our model is applicable to all types of spine fusion surgery and accounts for the complexity of surgical instrumentation, the number of levels instrumented, and the predicted duration of surgery as independent variables.

Renin-angiotensin system inhibitors and troponin elevation in spinal surgery.

Renin-angiotensin system (RAS) inhibition by angiotensin-converting enzyme inhibitors (ACEI)/angiotensin receptor blockers (ARB) has been shown to reduce cardiovascular mortality and non-fatal myocardial infarction (MI) in high-risk surgical patients. However, their effect in spinal surgery has not been explored. Our objective was to determine the effect of RAS inhibitors on postoperative troponin elevation in spinal fusions, and to examine their correlation with hospital stay. We retrospectively analyzed 208 consecutive patients receiving spinal fusions ⩾5 levels between 2007-2010 with a mean follow-up of 1.7 years. Inclusion criteria were age ⩾18 years, elective fusions for kyphoscoliosis, and semi-elective fusions for tumor or infection. Exclusion criteria were trauma and follow-up <1 year. Descriptives, frequencies, and logistic and linear regression were used to analyze troponin elevation (⩾0.04 ng/mL), peak troponin level, and hospital stay. The results featured 208 patients with a mean body mass index (BMI) 28.5 kg/m(2) who underwent 345 spinal fusions. ACEI/ARB were withheld the day prior to surgery in 121 patients with 11 patients noteworthy for intra-operative electrocardiogram changes, 126 patients with troponin elevation, and 14 MI identified prior to discharge. Multivariate logistic regression identified BMI (p=0.04), estimated blood loss (p=0.015), and preoperative ACEI/ARB (p=0.015, odds ratio=2.7) as significant independent predictors for postoperative troponin elevation. Multivariate linear regression showed preoperative Oswestry Disability Index (p=0.002), unplanned return to operating room (p=0.007), pneumonia prior to hospital discharge (p<0.01), and preoperative ACEI/ARB to be associated with hospital stay. In patients with spinal fusions ⩾5 levels, ACEI/ARB are independently associated with postoperative troponin elevation and increased hospital stay.

The impact of body mass index on hospital stay and complications after spinal fusion.

BACKGROUND: Obesity is a dominant public health concern and risk factor for disability, with few studies examining its impact in spinal surgery. Patients with a higher body mass index (BMI) have lower functional status, increased pain, and worse physical condition than those with ideal weight. OBJECTIVE: To determine associations between BMI categories on adverse patient outcomes after long-segment spinal fusions. METHODS: Consecutive, open, elective fusions (interbody and/or posterolateral arthrodesis) of more than 5 levels from 2007 to 2010 were retrospectively analyzed with follow-up of more than 1 year. Bivariate analyses examined outcome variables based on BMI categories. Linear regression analysis evaluated BMI, hospital stay, and complications at 1 and 2 years, controlling for confounders. Mean and median follow-up lengths were 2.1 and 2.0 years, respectively. RESULTS: A total of 189 surgeries on 112 patients, with a mean age of 59.5 years and a mean BMI of 29.8 kg/m, were analyzed. Morbidly obese patients had longer hospitalizations, worse Oswestry Disability Index (ODI), and more complications at 1 and 2 years than ideal weight patients. Multivariate linear regression modeling revealed sex, cardiac medications, cerebrospinal fluid leak, and BMI category of ideal vs nonideal influenced hospitalization length. Multivariate analysis showed BMI greater than 30 kg/m, preoperative ODI, and pedicle subtraction osteotomy influenced all complications at 1 year. Mean complications at 2 years for the morbidly obese were 3 times more than those underweight and 8 times more than those with ideal weight. Controlling for age, sex, and length of stay, obese and morbidly obese patients had more complications at 2 years; morbidly obese patients had a worse 2-year ODI. CONCLUSION: BMI is an independent predictor of hospitalization length and all complications at 1 and 2 years in patients receiving long-segment fusions.

Crouch gait in persons with positive sagittal spine alignment resolves with surgery.

OBJECTIVE: Degenerative spinal conditions often result in positive sagittal alignment which may be corrected using multi-segment spinal reconstructive surgeries. The purpose of this study was to investigate gait kinematics before and after spinal reconstructive surgery in persons with positive sagittal alignment. METHODS: Subjects presenting with positive sagittal alignment of greater than or equal to 7 cm who were treated with spinal reconstructive surgery were included in this study. Gait analyses were conducted pre- and 6 months post-operatively. Data were collected while subjects stood quietly for 20s and walked at their normal self-selected walking speed. RESULTS: For 12 subjects, sagittal spine alignment during standing and walking was significantly decreased post-operatively (p<0.0001 for standing and p<0.0005 for walking). Prior to surgery, the subjects appeared to adopt a crouch gait with the knee flexion angle at mid terminal stance decreasing significantly after surgery (p<0.0 for the dominant lower limb and p<0.0 for the non-dominant lower limb). Additionally, dominant step length (p<0.003) and non-dominant step length (p<0.001) increased significantly after surgery. CONCLUSIONS: Positive sagittal alignment resulted in crouch gait, which was resolved after multi-segment reconstructive spinal surgery that improved sagittal spinal alignment. Step and stride lengths also improved after surgical correction of the sagittal alignment.

Treatment algorithms and protocol practice in high-risk spine surgery.

The practice of appropriate evidence-based medicine should be a goal for all physicians. By using protocols in areas where strong evidence-based medicine exists, physicians have reliably shown they can improve patient outcomes while reducing complications, cost, and hospital stay. Evidence-based protocols in complex spinal care are rare. At Northwestern University the authors have developed a multidisciplinary protocol for the preoperative, intraoperative, and postoperative workup and care of complex spine patients. The rationale and use of the High-Risk Spine Protocol is discussed.

Redefining global spinal balance: normative values of cranial center of mass from a prospective cohort of asymptomatic individuals.

STUDY DESIGN: Prospective radiographical analysis of cranial center of mass (CCOM), C2, and C7 plumb lines in young and elderly asymptomatic individuals. OBJECTIVE: To establish a normal range for craniosagittal balance for both young and elderly asymptomatic individuals. SUMMARY OF BACKGROUND DATA: Global sagittal balance must account for the position of the head in relation to the spine and pelvis. The C7 plumb line defines thoracolumbar sagittal balance and has been shown to have significant impact on patient outcomes. However, the C7 plumb line fails to take into consideration the position of the head in relation to the pelvis. METHODS: A total of 100 asymptomatic 20- to 40-year-old patients and 100 asymptomatic 60- to 80-year-old patients were enrolled. Standing plain radiographs of 14 × 36 in were obtained. CCOM, C2, and C7 plumb lines were drawn and measured from the superoposterior endplate of S1. RESULTS: A total of 78 asymptomatic 20- to 40-year-old patients and 62 asymptomatic 60- to 80-year-old patients had adequate radiographs. The mean plumb line values in the 20- to 40-year-old patients and 60- to 80-year-old patients, respectively, were as follows; CCOM 9.0 mm (SD, 31.5 mm) and 41.2 mm (SD, 35.7 mm); C2 -2.7 mm (SD, 32.7 mm) and 32.1 mm (SD, 33.6 mm); and C7 -16.4 mm (SD, 31.5 mm) and 10.6 mm (SD, 27.8 mm). One-way analysis of variance and Student t tests confirmed that these mean plumb line values were significantly different between young and elderly patients (P < 0.001). The change at each level over time was highly correlated with the other levels (r > 0.97; P < 0.001) as did the degree of change between groups (r > 0.90, P < 0.001). CONCLUSION: Spinopelvic alignment in conjunction with CCOM has increased our understanding of spinal balance by including the head and may better represent true global spinal balance. CCOM is an easily measured parameter by using the nasion-inion technique.

Pharyngo-occipital artery variant arising from the internal carotid artery impacting surgical technique during carotid endarterectomy.

BACKGROUND AND IMPORTANCE: Extracranial carotid artery atherosclerotic stenosis typically occurs at the junction of the common carotid, external carotid and internal carotid arteries. Although rare, anatomical arterial variants can influence surgical strategy and can have a significant impact on surgical complications and patient outcome. An unusual case of atherosclerotic stenosis of the internal carotid artery (ICA) at the origin of a pharyngo-occipital variant off of the ICA is reported here. CLINICAL PRESENTATION: A 60-year-old man presented with symptomatic severe left cervical ICA stenosis. The stenosis was related to the origin of the pharyngo-occipital common trunk which arose from the ICA rather than the typical origin off of the external carotid artery. The patient underwent successful left carotid endarterectomy with special attention to this variant anatomy. CONCLUSION: Anomalies of the extracranial ICA, although rare, can influence the location of atherosclerotic disease and the surgical endarterectomy strategy. A detailed anatomical study should be performed prior to surgery to minimize risk and improve patient outcome.