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Objective: Correction of mild flexible cervical deformity (CD) via the posterior approach has been described with and without the use of posterior osteotomies (POs), despite a lack of clarity regarding their necessity or risks. The purpose of this study was to determine whether the use of POs when correcting mild flexible CD leads to improved clinical or radiographic outcomes, as well as defining the relative risks in utilizing them., Methods: A prospective multicenter registry of operative CD patients was analyzed. Inclusion criteria were cervical kyphosis > 10°, cervical scoliosis > 10°, cervical sagittal vertical axis (cSVA) > 4 cm, or chin-brow vertical angle > 25°. Mild deformity was defined by a cSVA of 3-5 cm and/or kyphosis < 15°. Flexibility was defined by a C2-7 angular change > 5° on preoperative flexion/extension radiographs. Patients who received a posterior column osteotomy (PCO) (Ames grades 1 and 2) were compared with patients who did not undergo a PCO (noPCO) as well as those who underwent a three-column osteotomy (3CO) (Ames grades 3-6)., Results: Ninety-five patients (33 PCO, 49 noPCO, 13 3CO) met the inclusion criteria. Both the number of levels fused (9.2 vs 7.7, p = 0.001) and the estimated blood loss (EBL) (1027 vs 486 mL, p = 0.012) were higher in the PCO cohort. Patients in the noPCO group were more likely to have a cervical apex of kyphosis (71.1%, p = 0.046), while those undergoing 3COs were more likely to have a thoracic apex (58.3%, p = 0.005). Preoperative cSVA (PCO vs noPCO: 45.4 vs 37.9 cm, p = 0.084), T1 slope (32.5° vs 29.6°, p = 0.376), C2-7 lordosis (-8.9° vs -9.2°, p = 0.942), and modified Japanese Orthopaedic Association (mJOA) score (13.4 vs 13.5, p = 0.854) were similar; however, both Neck Disability Index (NDI) (55.6 vs 42, p = 0.002) and numeric rating scale (NRS) neck (7.2 vs 5.8, p = 0.028) scores were higher in the PCO group before surgery. When adjusting for the use of an anterior approach, there was no significant difference in 1-year postoperative cSVA (35.7 and 35.6 cm, respectively; p = 0.969), C2-7 lordosis (13.7° and 10.1°, respectively; p = 0.393), and patient-reported outcome measures (NRS, NDI, and mJOA) between the PCO and noPCO groups. Two-year radiographic outcomes were largely similar, except for C2 slope, which was higher in the PCO group (29.1° vs 18°, p = 0.026). The overall complication rates progressively increased with more complex osteotomy use (noPCO 68.8% vs PCO 71.9% vs 3CO 75%) but did not reach significance (p = 0.063)., Conclusions: The use of POs for mild flexible adult CD may not be necessary to achieve desirable radiographic correction. They are associated with greater EBL and fusion burden. Further studies are needed to fully delineate the risks of adverse events for various types of osteotomies.

Objective: Sagittal alignment measured on standing radiography remains a fundamental component of surgical planning for adult spinal deformity (ASD). However, the relationship between classic sagittal alignment parameters and objective metrics, such as walking time (WT) and grip strength (GS), remains unknown. The objective of this work was to determine if ASD patients with worse baseline sagittal malalignment have worse objective physical metrics and if those metrics have a stronger relationship to patient-reported outcome metrics (PROMs) than standing alignment., Methods: The authors conducted a retrospective review of a multicenter ASD cohort. ASD patients underwent baseline testing with the timed up-and-go 6-m walk test (seconds) and for GS (pounds). Baseline PROMs were surveyed, including Oswestry Disability Index (ODI), Patient-Reported Outcomes Measurement Information System (PROMIS), Scoliosis Research Society (SRS)-22r, and Veterans RAND 12 (VR-12) scores. Standard spinopelvic measurements were obtained (sagittal vertical axis [SVA], pelvic tilt [PT], and mismatch between pelvic incidence and lumbar lordosis [PI-LL], and SRS-Schwab ASD classification). Univariate and multivariable linear regression modeling was performed to interrogate associations between objective physical metrics, sagittal parameters, and PROMs., Results: In total, 494 patients were included, with mean ± SD age 61 ± 14 years, and 68% were female. Average WT was 11.2 ± 6.1 seconds and average GS was 56.6 ± 24.9 lbs. With increasing PT, PI-LL, and SVA quartiles, WT significantly increased (p < 0.05). SRS-Schwab type N patients demonstrated a significantly longer average WT (12.5 ± 6.2 seconds), and type T patients had a significantly shorter WT time (7.9 ± 2.7 seconds, p = 0.03). With increasing PT quartiles, GS significantly decreased (p < 0.05). SRS-Schwab type T patients had a significantly higher average GS (68.8 ± 27.8 lbs), and type L patients had a significantly lower average GS (51.6 ± 20.4 lbs, p = 0.03). In the frailty-adjusted multivariable linear regression analyses, WT was more strongly associated with PROMs than sagittal parameters. GS was more strongly associated with ODI and PROMIS Physical Function scores., Conclusions: The authors observed that increasing baseline sagittal malalignment is associated with slower WT, and possibly weaker GS, in ASD patients. WT has a stronger relationship to PROMs than standing alignment parameters. Objective physical metrics likely offer added value to standard spinopelvic measurements in ASD evaluation and surgical planning.

Objective: Complex spinal deformity surgeries may involve significant blood loss. The use of antifibrinolytic agents such as tranexamic acid (TXA) has been proven to reduce perioperative blood loss. However, for patients with a history of thromboembolic events, there is concern of increased risk when TXA is used during these surgeries. This study aimed to assess whether TXA use in patients undergoing complex spinal deformity correction surgeries increases the risk of thromboembolic complications based on preexisting thromboembolic risk factors., Methods: Data were analyzed for adult patients who received TXA during surgical correction for spinal deformity at 21 North American centers between August 2018 and October 2022. Patients with preexisting thromboembolic events and other risk factors (history of deep venous thrombosis [DVT], pulmonary embolism [PE], myocardial infarction [MI], stroke, peripheral vascular disease, or cancer) were identified. Thromboembolic complication rates were assessed during the postoperative 90 days. Univariate and multivariate analyses were performed to assess thromboembolic outcomes in high-risk and low-risk patients who received intravenous TXA., Results: Among 411 consecutive patients who underwent complex spinal deformity surgery and received TXA intraoperatively, 130 (31.6%) were considered high-risk patients. There was no significant difference in thromboembolic complications between patients with and those without preexisting thromboembolic risk factors in univariate analysis (high-risk group vs low-risk group: 8.5% vs 2.8%, p = 0.45). Specifically, there were no significant differences between groups regarding the 90-day postoperative rates of DVT (high-risk group vs low-risk group: 1.5% vs 1.4%, p = 0.98), PE (2.3% vs 1.8%, p = 0.71), acute MI (1.5% vs 0%, p = 0.19), or stroke (0.8% vs 1.1%, p > 0.99). On multivariate analysis, high-risk status was not a significant independent predictor for any of the thromboembolic complications., Conclusions: Administration of intravenous TXA during the correction procedure did not change rates of thromboembolic events, acute MI, or stroke in this cohort of adult spinal deformity surgery patients.

Objective: The present study utilized recently developed in-construct measurements in simulations of cervical deformity surgery in order to assess undercorrection and predict distal junctional kyphosis (DJK)., Methods: A retrospective review of a database of operative cervical deformity patients was analyzed for severe DJK and mild DJK. C2-lower instrumented vertebra (LIV) sagittal angle (SA) was measured postoperatively, and the correction was simulated in the preoperative radiograph in order to match the C2-LIV by using the planning software. Linear regression analysis that used C2 pelvic angle (CPA) and pelvic tilt (PT) determined the simulated PT that matched the virtual CPA. Linear regression analysis was used to determine the C2-T1 SA, C2-T4 SA, and C2-T10 SA that corresponded to DJK of 20° and cervical sagittal vertical axis (cSVA) of 40 mm., Results: Sixty-nine cervical deformity patients were included. Severe and mild DJK occurred in 11 (16%) and 22 (32%) patients, respectively; 3 (4%) required DJK revision. Simulated corrections demonstrated that severe and mild DJK patients had worse alignment compared to non-DJK patients in terms of cSVA (42.5 mm vs 33.0 mm vs 23.4 mm, p < 0.001) and C2-LIV SVA (68.9 mm vs 57.3 mm vs 36.8 mm, p < 0.001). Linear regression revealed the relationships between in-construct measures (C2-T1 SA, C2-T4 SA, and C2-T10 SA), cSVA, and change in DJK (all R > 0.57, p < 0.001). A cSVA of 40 mm corresponded to C2-T4 SA of 10.4° and C2-T10 SA of 28.0°. A DJK angle change of 10° corresponded to C2-T4 SA of 5.8° and C2-T10 SA of 20.1°., Conclusions: Simulated cervical deformity corrections demonstrated that severe DJK patients have insufficient corrections compared to patients without DJK. In-construct measures assess sagittal alignment within the fusion separate from DJK and subjacent compensation. They can be useful as intraoperative tools to gauge the adequacy of cervical deformity correction.

Objective: The objective was to evaluate the efficacy, outcomes, and complications of surgical intervention performed within 24 hours (≤ 24 hours) versus after 24 hours (> 24 hours) in managing acute traumatic central cord syndrome (ATCCS)., Methods: Articles pertinent to the study were retrieved from PubMed, Scopus, Web of Science, and Cochrane. The authors performed a systematic review and meta-analysis of treatment procedures and outcomes according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRIMSA) guidelines., Results: Seven articles comprising 488 patients were included, with 188 (38.5%) patients in the ≤ 24-hour group and 300 (61.5%) in the > 24-hour group. Significant differences were not found between groups in terms of demographic characteristics, injury mechanism, spinal cord compression level, neuroimaging features, and the American Spinal Injury Association (ASIA) motor score at admission. Both groups had a similar approach to surgery and steroid administration. The surgical complication rate was significantly higher in the > 24-hour group (4.5%) compared to the ≤ 24-hour group (1.2%) (p = 0.05). Clinical follow-up duration was similar at 12 months (interquartile range 3-36) for both groups (p > 0.99). The ≤ 24-hour group demonstrated a not statistically significant greater improvement in ASIA motor score, with a mean difference of 12 (95% CI -20.7 to 44.6) compared to the > 24-hour group., Conclusions: The present study indicates potential advantages of early (≤ 24 hours) surgery in ATCCS patients, specifically in terms of lower complication rates. However, further research is needed to confirm these findings and their clinical implications.

Objective: The objective was to determine the degree of regional decompensation to pelvic tilt (PT) normalization after complex adult spinal deformity (ASD) surgery., Methods: Operative ASD patients with 1 year of PT measurements were included. Patients with normalized PT at baseline were excluded. Predicted PT was compared to actual PT, tested for change from baseline, and then compared against age-adjusted, Scoliosis Research Society-Schwab, and global alignment and proportion (GAP) scores. Lower-extremity (LE) parameters included the cranial-hip-sacrum angle, cranial-knee-sacrum angle, and cranial-ankle-sacrum angle. LE compensation was set as the 1-year upper tertile compared with intraoperative baseline. Univariate analyses were used to compare normalized and nonnormalized data against alignment outcomes. Multivariable logistic regression analyses were used to develop a model consisting of significant predictors for normalization related to regional compensation., Results: In total, 156 patients met the inclusion criteria (mean ± SD age 64.6 ± 9.1 years, BMI 27.9 ± 5.6 kg/m2, Charlson Comorbidity Index 1.9 ± 1.6). Patients with normalized PT were more likely to have overcorrected pelvic incidence minus lumbar lordosis and sagittal vertical axis at 6 weeks (p < 0.05). GAP score at 6 weeks was greater for patients with nonnormalized PT (0.6 vs 1.3, p = 0.08). At baseline, 58.5% of patients had compensation in the thoracic and cervical regions. Postoperatively, compensation was maintained by 42% with no change after matching in age-adjusted or GAP score. The patients with nonnormalized PT had increased rates of thoracic and cervical compensation (p < 0.05). Compensation in thoracic kyphosis differed between patients with normalized PT at 6 weeks and those with normalized PT at 1 year (69% vs 35%, p < 0.05). Those who compensated had increased rates of implant complications by 1 year (OR [95% CI] 2.08 [1.32-6.56], p < 0.05). Cervical compensation was maintained at 6 weeks and 1 year (56% vs 43%, p = 0.12), with no difference in implant complications (OR 1.31 [95% CI -2.34 to 1.03], p = 0.09). For the lower extremities at baseline, 61% were compensating. Matching age-adjusted alignment did not eliminate compensation at any joint (all p > 0.05). Patients with nonnormalized PT had higher rates of LE compensation across joints (all p < 0.01). Overall, patients with normalized PT at 1 year had the greatest odds of resolving LE compensation (OR 9.6, p < 0.001). Patients with normalized PT at 1 year had lower rates of implant failure (8.9% vs 19.5%, p < 0.05), rod breakage (1.3% vs 13.8%, p < 0.05), and pseudarthrosis (0% vs 4.6%, p < 0.05) compared with patients with nonnormalized PT. The complication rate was significantly lower for patients with normalized PT at 1 year (56.7% vs 66.1%, p = 0.02), despite comparable health-related quality of life scores., Conclusions: Patients with PT normalization had greater rates of resolution in thoracic and LE compensation, leading to lower rates of complications by 1 year. Thus, consideration of both the lower extremities and thoracic regions in surgical planning is vital to preventing adverse outcomes and maintaining pelvic alignment.

Objective: The purpose of this study was to investigate the cost utility of nonoperative treatment for adult spinal deformity (ASD)., Methods: Nonoperatively and operatively treated patients who met database criteria for ASD and in whom complete radiographic and health-related quality of life data at baseline and at 2 years were available were included. A cost analysis was completed on the PearlDiver database assessing the average cost of nonoperative treatment prior to surgical intervention based on previously published treatments (NSAIDs, narcotics, muscle relaxants, epidural steroid injections, physical therapy, and chiropractor). Utility data were calculated using the Oswestry Disability Index (ODI) converted to SF-6D with published conversion methods. Quality-adjusted life years (QALYs) used a 3% discount rate to account for residual decline in life expectancy (78.7 years). Minor and major comorbidities and complications were assessed according to the CMS.gov manual's definitions. Successful nonoperative treatment was defined as a gain in the minimum clinically importance difference (MCID) in both ODI and Scoliosis Research Society (SRS)-pain scores, and failure was defined as a loss in MCID or conversion to operative treatment. Patients with baseline ODI ≤ 20 and continued ODI of ≤ 20 at 2 years were considered nonoperative successful maintenance. The average utilization of nonoperative treatment and cost were applied to the ASD cohort., Results: A total of 824 patients were included (mean age 58.24 years, 81% female, mean body mass index 27.2 kg/m2). Overall, 75.5% of patients were in the operative and 24.5% were in the nonoperative cohort. At baseline patients in the operative cohort were significantly older, had a greater body mass index, increased pelvic tilt, and increased pelvic incidence-lumbar lordosis mismatch (all p < 0.05). With respect to deformity, patients in the operative group had higher rates of severe (i.e., ++) sagittal deformity according to SRS-Schwab modifiers for pelvic tilt, sagittal vertical axis, and pelvic incidence-lumbar lordosis mismatch (p < 0.05). At 2 years, patients in the operative cohort showed significantly increased rates of a gain in MCID for physical component summary of SF-36, ODI, and SRS-activity, SRS-pain, SRS-appearance, and SRS-mental scores. Cost analysis showed the average cost of nonoperative treatment 2 years prior to surgical intervention to be $2041. Overall, at 2 years patients in the nonoperative cohort had again in ODI of 0.36, did not show a gain in QALYs, and nonoperative treatment was determined to be cost-ineffective. However, a subset of patients in this cohort underwent successful maintenance treatment and had a decrease in ODI of 1.1 and a gain in utility of 0.006 at 2 years. If utility gained for this cohort was sustained to full life expectancy, patients' cost per QALY was $18,934 compared to a cost per QALY gained of $70,690.79 for posterior-only and $48,273.49 for combined approach in patients in the operative cohort., Conclusions: Patients with ASD undergoing operative treatment at baseline had greater sagittal deformity and greater improvement in health-related quality of life postoperatively compared to patients treated nonoperatively. Additionally, patients in the nonoperative cohort overall had an increase in ODI and did not show improvement in utility gained. Patients in the nonoperative cohort who had low disability and sagittal deformity underwent successful maintenance and cost-effective treatment.

Objective: The authors of this study sought to evaluate the predictive role of global sagittal alignment and upper instrumented vertebra (UIV) level in symptomatic proximal junctional kyphosis (PJK) among patients with adult spinal deformity (ASD)., Methods: Data on ASD patients who had undergone fusion of ≥ 5 vertebrae from 2008 to 2018 and with a minimum follow-up of 1 year were obtained from a prospectively collected multicenter database and evaluated (n = 1312). Radiographs were obtained preoperatively and at 6 weeks, 6 months, 1 year, 2 years, and 3 years postoperatively. The 22-Item Scoliosis Research Society Patient Questionnaire Revised (SRS-22r) scores were collected preoperatively, 1 year postoperatively, and 2 years postoperatively. Symptomatic PJK was defined as a kyphotic increase > 20° in the Cobb angle from the UIV to the UIV+2. At 6 weeks postoperatively, sagittal parameters were evaluated and patients were categorized by global alignment and proportion (GAP) score/category and SRS-Schwab sagittal modifiers. Patients were stratified by UIV level: upper thoracic (UT) UIV ≥ T8 or lower thoracic (LT) UIV ≤ T9., Results: Patients who developed symptomatic PJK (n = 260) had worse 1-year postoperative SRS-22r mental health (3.70 vs 3.86) and total (3.56 vs 3.67) scores, as well as worse 2-year postoperative self-image (3.45 vs 3.65) and satisfaction (4.03 vs 4.22) scores (all p ≤ 0.04). In the whole study cohort, patients with PJK had less pelvic incidence-lumbar lordosis (PI-LL) mismatch (-0.24° vs 3.29°, p < 0.001) but no difference in their GAP score/category or SRS-Schwab sagittal modifiers compared with the patients without PJK. Regression showed a higher risk of PJK with a pelvic tilt (PT) grade ++ (OR 2.35) and less risk with a PI-LL grade ++ (OR 0.35; both p < 0.01). When specifically analyzing the LT UIV cohort, patients with PJK had a higher GAP score (5.66 vs 4.79), greater PT (23.02° vs 20.90°), and less PI-LL mismatch (1.61° vs 4.45°; all p ≤ 0.02). PJK patients were less likely to be proportioned postoperatively (17.6% vs 30.0%, p = 0.015), and regression demonstrated a greater PJK risk with severe disproportion (OR 1.98) and a PT grade ++ (OR 3.15) but less risk with a PI-LL grade ++ (OR 0.45; all p ≤ 0.01). When specifically evaluating the UT UIV cohort, the PJK patients had less PI-LL mismatch (-2.11° vs 1.45°) but no difference in their GAP score/category. Regression showed a greater PJK risk with a PT grade + (OR 1.58) and a decreased risk with a PI-LL grade ++ (OR 0.21; both p < 0.05)., Conclusions: Symptomatic PJK leads to worse patient-reported outcomes and is associated with less postoperative PI-LL mismatch and greater postoperative PT. A worse postoperative GAP score and disproportion are only predictive of symptomatic PJK in patients with an LT UIV.

Objective: The objective of this study was to identify the effect of baseline cervical deformity (CD) on proximal junctional kyphosis (PJK) and proximal junctional failure (PJF) in patients with adult spinal deformity (ASD)., Methods: This study was a retrospective analysis of a prospectively collected, multicenter database comprising ASD patients enrolled at 13 participating centers from 2009 to 2018. Included were ASD patients aged > 18 years with concurrent CD (C2-7 kyphosis < -15°, T1S minus cervical lordosis > 35°, C2-7 sagittal vertical axis > 4 cm, chin-brow vertical angle > 25°, McGregor's slope > 20°, or C2-T1 kyphosis > 15° across any three vertebrae) who underwent surgery. Patients were grouped according to four deformity classification schemes: Ames and Passias CD modifiers, sagittal morphotypes as described by Kim et al., and the head versus trunk balance system proposed by Mizutani et al. Mean comparison tests and multivariable binary logistic regression analyses were performed to assess the impact of these deformity classifications on PJK and PJF rates up to 3 years following surgery., Results: A total of 712 patients with concurrent ASD and CD met the inclusion criteria (mean age 61.7 years, 71% female, mean BMI 28.2 kg/m2, and mean Charlson Comorbidity Index 1.90) and underwent surgery (mean number of levels fused 10.1, mean estimated blood loss 1542 mL, and mean operative time 365 minutes; 70% underwent osteotomy). By approach, 59% of the patients underwent a posterior-only approach and 41% underwent a combined approach. Overall, 277 patients (39.1%) had PJK by 1 year postoperatively, and an additional 189 patients (26.7%) developed PJK by 3 years postoperatively. Overall, 65 patients (9.2%) had PJF by 3 years postoperatively. Patients classified as having a cervicothoracic deformity morphotype had higher rates of early PJK than flat neck deformity and cervicothoracic deformity patients (p = 0.020). Compared with the head-balanced patients, trunk-balanced patients had higher rates of PJK and PJF (both p < 0.05). Examining Ames modifier severity showed that patients with moderate and severe deformity by the horizontal gaze modifier had higher rates of PJK (p < 0.001)., Conclusions: In patients with concurrent cervical and thoracolumbar deformities undergoing isolated thoracolumbar correction, the use of CD classifications allows for preoperative assessment of the potential for PJK and PJF that may aid in determining the correction of extending fusion levels.

Objective: Multiple rods are utilized in adult spinal deformity (ASD) surgery to increase construct stiffness. However, the impact of multiple rods on proximal junctional kyphosis (PJK) is not well established. This study aimed to investigate the impact of multiple rods on PJK incidence in ASD patients., Methods: ASD patients from a prospective multicenter database with a minimum follow-up of 1 year were retrospectively reviewed. Clinical and radiographic data were collected preoperatively, at 6 weeks postoperatively, at 6 months postoperatively, at 1 year postoperatively, and at every subsequent year postoperatively. PJK was defined as a kyphotic increase of > 10° in the Cobb angle from the upper instrumented vertebra (UIV) to UIV+2 as compared with preoperative values. Demographic data, radiographic parameters, and PJK incidence were compared between the multirod and dual-rod patient cohorts. PJK-free survival analysis was performed using Cox regression to control for demographic characteristics, comorbidities, level of fusion, and radiographic parameters., Results: Overall, 307/1300 (23.62%) cases utilized multiple rods. Cases with multiple rods were more likely to be revisions (68.4% vs 46.5%, p < 0.001), to be posterior only (80.7% vs 61.5%, p < 0.001), involve more levels of fusion (mean 11.73 vs 10.60, p < 0.001), and include 3-column osteotomy (42.9% vs 17.1%, p < 0.001). Patients with multiple rods also had greater preoperative pelvic retroversion (mean pelvic tilt 27.95° vs 23.58°, p < 0.001), greater thoracolumbar junction kyphosis (-15.9° vs -11.9°, p = 0.001), and more severe sagittal malalignment (C7-S1 sagittal vertical axis 99.76 mm vs 62.23 mm, p < 0.001), all of which corrected postoperatively. Patients with multiple rods had similar incidence rates of PJK (58.6% vs 58.1%) and revision surgery (13.0% vs 17.7%). The PJK-free survival analysis demonstrated equivalent PJK-free survival durations among the patients with multiple rods (HR 0.889, 95% CI 0.745-1.062, p = 0.195) after controlling for demographic and radiographic parameters. Further stratification based on implant metal type demonstrated noninferior PJK incidence rates with multiple rods in the titanium (57.1% vs 54.6%, p = 0.858), cobalt chrome (60.5% vs 58.7%, p = 0.646), and stainless steel (20% vs 63.7%, p = 0.008) cohorts., Conclusions: Multirod constructs for ASD are most frequently utilized in revision, long-level reconstructions with 3-column osteotomy. The use of multiple rods in ASD surgery does not result in an increased incidence of PJK and is not affected by rod metal type.

Objective: The objective of this study was to calibrate an updated predictive model incorporating novel clinical, radiographic, and prophylactic measures to assess the risk of proximal junctional kyphosis (PJK) and failure (PJF)., Methods: Operative patients with adult spinal deformity (ASD) and baseline and 2-year postoperative data were included. PJK was defined as ≥ 10° in sagittal Cobb angle between the inferior uppermost instrumented vertebra (UIV) endplate and superior endplate of the UIV + 2 vertebrae. PJF was radiographically defined as a proximal junctional sagittal Cobb angle ≥ 15° with the presence of structural failure and/or mechanical instability, or PJK with reoperation. Backstep conditional binary supervised learning models assessed baseline demographic, clinical, and surgical information to predict the occurrence of PJK and PJF. Internal cross validation of the model was performed via a 70%/30% cohort split. Conditional inference tree analysis determined thresholds at an alpha level of 0.05., Results: Seven hundred seventy-nine patients with ASD (mean 59.87 ± 14.24 years, 78% female, mean BMI 27.78 ± 6.02 kg/m2, mean Charlson Comorbidity Index 1.74 ± 1.71) were included. PJK developed in 50.2% of patients, and 10.5% developed PJF by their last recorded visit. The six most significant demographic, radiographic, surgical, and postoperative predictors of PJK/PJF were baseline age ≥ 74 years, baseline sagittal age-adjusted score (SAAS) T1 pelvic angle modifier > 1, baseline SAAS pelvic tilt modifier > 0, levels fused > 10, nonuse of prophylaxis measures, and 6-week SAAS pelvic incidence minus lumbar lordosis modifier > 1 (all p < 0.015). Overall, the model was deemed significant (p < 0.001), and internally validated receiver operating characteristic analysis returned an area under the curve of 0.923, indicating robust model fit., Conclusions: PJK and PJF remain critical concerns in ASD surgery, and efforts to reduce the occurrence of PJK and PJF have resulted in the development of novel prophylactic techniques and enhanced clinical and radiographic selection criteria. This study demonstrates a validated model incorporating such techniques that may allow for the prediction of clinically significant PJK and PJF, and thus assist in optimizing patient selection, enhancing intraoperative decision making, and reducing postoperative complications in ASD surgery.

Objective: Lumbar interbody cage subsidence has a multifactorial etiology. Cage material, although well studied after transforaminal lumbar interbody fusion, has not been investigated as a contributing factor to subsidence after lateral lumbar interbody fusion (LLIF). In this study the authors compared rates of subsidence and reoperation after LLIF between polyetheretherketone (PEEK) and 3D-printed porous titanium (pTi) in an institutional propensity score-matched and cost analysis., Methods: This is a retrospective observational cohort analysis of adult patients who underwent LLIF with pTi versus PEEK between 2016 and 2020. Demographic, clinical, and radiographic characteristics were collected. Propensity scores were calculated and 1:1 matching without replacement of surgically treated levels was performed. The primary outcome of interest was subsidence. The Marchi subsidence grade was determined at the time of last follow-up. Chi-square or Fisher's exact tests were used to compare subsidence and reoperation rates between lumbar levels treated with PEEK versus pTi. Modeling and cost analysis were performed using TreeAge Pro Healthcare., Results: The authors identified a total of 192 patients; 137 underwent LLIF with PEEK (212 levels) and 55 had LLIF with pTi (97 levels). After propensity score matching, a total of 97 lumbar levels remained in each treatment group. After matching, there were no statistically significant differences between groups in baseline characteristics. Levels treated with pTi were significantly less likely to exhibit subsidence (any grade) compared to those treated with PEEK (8% vs 27%, p = 0.001). Five (5.2%) levels treated with PEEK required reoperation for subsidence, but only 1 (1.0%) level treated with pTi required reoperation for subsidence (p = 0.12). Given subsidence and revision rates experienced in the cohorts in this study, the pTi interbody device is economically superior to PEEK in a single-level LLIF as long as its cost is at least $1185.94 lower than that of PEEK., Conclusions: The pTi interbody device was associated with less subsidence, but statistically similar revision rates after LLIF. pTi is potentially a superior economic choice at this study's reported revision rate.

In this review, the value of patient-reported outcome measures, immersive technology, and patient review systems is discussed, and these strategies are presented as ways to enhance both the research and clinical aspects of a practice. The value of a research team and open access research databases is also discussed. Establishing a research program does not need elaborate resources to sustain efforts. The aforementioned simple yet effective strategies can enhance the clinical and research experience for surgeons in both academic and private practice settings.

Objective: Revision surgery is often necessary for adult spinal deformity (ASD) patients. Satisfaction with management is an important component of health-related quality of life. The authors hypothesized that patients who underwent multiple revision surgeries following ASD correction would exhibit lower self-reported satisfaction scores., Methods: This was a retrospective cohort study of 668 patients who underwent ASD surgery and were eligible for a minimum 2-year follow-up. Visits were stratified by occurrence prior to the index surgery (period 0), after the index surgery only (period 1), after the first revision only (period 2), and after the second revision only (period 3). Patients were further stratified by prior spine surgery before their index surgery. Scoliosis Research Society-22 (SRS-22r) health-related quality-of-life satisfaction subscore and total satisfaction scores were evaluated at all periods using multiple linear regression and adjustment for age, sex, and Charlson Comorbidity Index., Results: In total, 46.6% of the study patients had undergone prior spine surgery before their index surgery. The overall revision rate was 21.3%. Among patients with no spine surgery prior to the index surgery, SRS-22r satisfaction scores increased from period 0 to 1 (from 2.8 to 4.3, p < 0.0001), decreased after one revision from period 1 to 2 (4.3 to 3.9, p = 0.0004), and decreased further after a second revision from period 2 to 3 (3.9 to 3.3, p = 0.0437). Among patients with spine surgery prior to the index procedure, SRS-22r satisfaction increased from period 0 to 1 (2.8 to 4.2, p < 0.0001) and decreased from period 1 to 2 (4.2 to 3.8, p = 0.0011). No differences in follow-up time from last surgery were observed (all p > 0.3). Among patients with multiple revisions, 40% experienced rod fracture, 40% proximal junctional kyphosis, and 33% pseudarthrosis., Conclusions: Among patients undergoing ASD surgery, revision surgery is associated with decreased satisfaction, and multiple revisions are associated with additive detriment to satisfaction among patients initially undergoing primary surgery. These findings have direct implications for preoperative patient counseling and establishment of postoperative expectations.

Objective: Adult cervical deformity (ACD) has high complication rates due to surgical complexity and patient frailty. Very few studies have focused on longer-term outcomes of operative ACD treatment. The objective of this study was to assess minimum 2-year outcomes and complications of ACD surgery., Methods: A multicenter, prospective observational study was performed at 13 centers across the United States to evaluate surgical outcomes for ACD. Demographics, complications, radiographic parameters, and patient-reported outcome measures (PROMs; Neck Disability Index, modified Japanese Orthopaedic Association, EuroQol-5D [EQ-5D], and numeric rating scale [NRS] for neck and back pain) were evaluated, and analyses focused on patients with ≥ 2-year follow-up., Results: Of 169 patients with ACD who were eligible for the study, 102 (60.4%) had a minimum 2-year follow-up (mean 3.4 years, range 2-8.1 years). The mean age at surgery was 62 years (SD 11 years). Surgical approaches included anterior-only (22.8%), posterior-only (39.6%), and combined (37.6%). PROMs significantly improved from baseline to last follow-up, including Neck Disability Index (from 47.3 to 33.0) and modified Japanese Orthopaedic Association score (from 12.0 to 12.8; for patients with baseline score ≤ 14), neck pain NRS (from 6.8 to 3.8), back pain NRS (from 5.5 to 4.8), EQ-5D score (from 0.74 to 0.78), and EQ-5D visual analog scale score (from 59.5 to 66.6) (all p ≤ 0.04). More than half of the patients (n = 58, 56.9%) had at least one complication, with the most common complications including dysphagia, distal junctional kyphosis, instrumentation failure, and cardiopulmonary events. The patients who did not achieve 2-year follow-up (n = 67) were similar to study patients based on baseline demographics, comorbidities, and PROMs. Over the course of follow-up, 23 of the total 169 enrolled patients were reported to have died. Notably, these represent all-cause mortalities during the course of follow-up., Conclusions: This multicenter, prospective analysis demonstrates that operative treatment for ACD provides significant improvement of health-related quality of life at a mean 3.4-year follow-up, despite high complication rates and a high rate of all-cause mortality that is reflective of the overall frailty of this patient population. To the authors' knowledge, this study represents the largest and most comprehensive prospective effort to date designed to assess the intermediate-term outcomes and complications of operative treatment for ACD.

Objective: Cage subsidence is a well-known phenomenon after lateral lumbar interbody fusion (LLIF), occurring in 10%-20% of cases. A 3D-printed porous titanium (pTi) cage has a stiffness that mimics the modulus of elasticity of native vertebrae, which reduces stress at the bone-hardware interface, lowering the risk of subsidence. In this study, the authors evaluated their institutional rate of subsidence and resultant reoperation in patients who underwent LLIF using a 3D-printed pTi interbody cage., Methods: This is a retrospective case series of consecutive adult patients who underwent LLIF using pTi cages from 2018 to 2020. Demographic and clinical characteristics including age, sex, bone mineral density, smoking status, diabetes, steroid use, number of fusion levels, posterior instrumentation, and graft size were collected. The Marchi subsidence grade was determined at the time of last follow-up. Outcome measures of interest were subsidence and resultant reoperation. Univariable logistic regression analysis was performed to assess the extent to which clinical and operative characteristics were associated with Marchi grade I-III subsidence. Significance was assessed at p < 0.05., Results: Fifty-five patients (38 with degenerative disc disease and 17 with adult spinal deformity) were treated with 97 pTi interbody cages with a mean follow-up of 18 months. The mean age was 63.6 ± 10.1 years, 60% of patients were female, and 36% of patients had osteopenia or osteoporosis. Patients most commonly underwent single-level LLIF (58.2%). Sixteen patients (29.1%) had posterior instrumentation. The subsidence grade distribution was as follows: 89 (92%) grade 0, 5 (5%) grade I, 2 (2%) grade II, and 1 (1%) grade III. No patients who were active or prior smokers and no patients with posterior instrumentation experienced graft subsidence. No clinical or operative characteristics were significantly associated with graft subsidence. One patient (1.8%) required reoperation because of subsidence., Conclusions: In this institutional case series, subsidence of pTi intervertebral cages after LLIF occurred in 8% of operated levels, 3% of which were grade II or III. Only 1 patient required reoperation. These reported rates are lower than those reported for polyetheretherketone implants. Further studies are necessary to compare the impact of these cage materials on subsidence after LLIF.

Objective: The current literature has primarily focused on the 2-year outcomes of operative adult spinal deformity (ASD) treatment. Longer term durability is important given the invasiveness, complications, and costs of these procedures. The aim of this study was to assess minimum 3-year outcomes and complications of ASD surgery., Methods: Operatively treated ASD patients were assessed at baseline, follow-up, and through mailings. Patient-reported outcome measures (PROMs) included scores on the Oswestry Disability Index (ODI), Scoliosis Research Society-22r (SRS-22r) questionnaire, mental component summary (MCS) and physical component summary (PCS) of the SF-36, and numeric rating scale (NRS) for back and leg pain. Complications were classified as perioperative (≤ 90 days), delayed (90 days to 2 years), and long term (≥ 2 years). Analyses focused on patients with minimum 3-year follow-up., Results: Of 569 patients, 427 (75%) with minimum 3-year follow-up (mean ± SD [range] 4.1 ± 1.1 [3.0-9.6] years) had a mean age of 60.8 years and 75% were women. Operative treatment included a posterior approach for 426 patients (99%), with a mean ± SD 12 ± 4 fusion levels. Anterior lumbar interbody fusion was performed in 35 (8%) patients, and 89 (21%) underwent 3-column osteotomy. All PROMs improved significantly from baseline to last follow-up, including scores on ODI (45.4 to 30.5), PCS (31.0 to 38.5), MCS (45.3 to 50.6), SRS-22r total (2.7 to 3.6), SRS-22r activity (2.8 to 3.5), SRS-22r pain (2.3 to 3.4), SRS-22r appearance (2.4 to 3.5), SRS-22r mental (3.4 to 3.7), SRS-22r satisfaction (2.7 to 4.1), NRS for back pain (7.1 to 3.8), and NRS for leg pain (4.8 to 3.0) (all p < 0.001). Degradations in some outcome measures were observed between the 2-year and last follow-up evaluations, but the magnitudes of these degradations were modest and arguably not clinically significant. Overall, 277 (65%) patients had at least 1 complication, including 185 (43%) perioperative, 118 (27%) delayed, and 56 (13%) long term. Notably, the 142 patients who did not achieve 3-year follow-up were similar to the study patients in terms of demographic characteristics, deformities, and baseline PROMs and had similar rates and types of complications., Conclusions: This prospective multicenter analysis demonstrated that operative ASD treatment provided significant improvement of health-related quality of life at minimum 3-year follow-up (mean 4.1 years), suggesting that the benefits of surgery for ASD remain durable at longer follow-up. These findings should prove useful for counseling, cost-effectiveness assessments, and efforts to improve the safety of care.

Objective: Deterioration of global coronal alignment (GCA) may be associated with worse outcomes after adult spinal deformity (ASD) surgery. The impact of fusion length and upper instrumented vertebra (UIV) selection on patients with this complication is unclear. The authors' objective was to compare outcomes between long sacropelvic fusion with upper-thoracic (UT) UIV and those with lower-thoracic (LT) UIV in patients with worsening GCA ≥ 1 cm., Methods: This was a retrospective analysis of a prospective multicenter database of consecutive ASD patients. Index operations involved instrumented fusion from sacropelvis to thoracic spine. Global coronal deterioration was defined as worsening GCA ≥ 1 cm from preoperation to 2-year follow-up., Results: Of 875 potentially eligible patients, 560 (64%) had complete 2-year follow-up data, of which 144 (25.7%) demonstrated worse GCA at 2-year postoperative follow-up (35.4% of UT patients vs 64.6% of LT patients). At baseline, UT patients were younger (61.6 ± 9.9 vs 64.5 ± 8.6 years, p = 0.008), a greater percentage of UT patients had osteoporosis (35.3% vs 16.1%, p = 0.009), and UT patients had worse scoliosis (51.9° ± 22.5° vs 32.5° ± 16.3°, p < 0.001). Index operations were comparable, except UT patients had longer fusions (16.4 ± 0.9 vs 9.7 ± 1.2 levels, p < 0.001) and operative duration (8.6 ± 3.2 vs 7.6 ± 3.0 hours, p = 0.023). At 2-year follow-up, global coronal deterioration averaged 2.7 ± 1.4 cm (1.9 to 4.6 cm, p < 0.001), scoliosis improved (39.3° ± 20.8° to 18.0° ± 14.8°, p < 0.001), and sagittal spinopelvic alignment improved significantly in all patients. UT patients maintained smaller positive C7 sagittal vertical axis (2.7 ± 5.7 vs 4.7 ± 5.7 cm, p = 0.014). Postoperative 2-year health-related quality of life (HRQL) significantly improved from baseline for all patients. HRQL comparisons demonstrated that UT patients had worse Scoliosis Research Society-22r (SRS-22r) Activity (3.2 ± 1.0 vs 3.6 ± 0.8, p = 0.040) and SRS-22r Satisfaction (3.9 ± 1.1 vs 4.3 ± 0.8, p = 0.021) scores. Also, fewer UT patients improved by ≥ 1 minimal clinically important difference in numerical rating scale scores for leg pain (41.3% vs 62.7%, p = 0.020). Comparable percentages of UT and LT patients had complications (208 total, including 53 reoperations, 77 major complications, and 78 minor complications), but the percentage of reoperated patients was higher among UT patients (35.3% vs 18.3%, p = 0.023). UT patients had higher reoperation rates of rod fracture (13.7% vs 2.2%, p = 0.006) and pseudarthrosis (7.8% vs 1.1%, p = 0.006) but not proximal junctional kyphosis (9.8% vs 8.6%, p = 0.810)., Conclusions: In ASD patients with worse 2-year GCA after long sacropelvic fusion, UT UIV was associated with worse 2-year HRQL compared with LT UIV. This may suggest that residual global coronal malalignment is clinically less tolerated in ASD patients with longer fusion to the proximal thoracic spine. These results may inform operative planning and improve patient counseling.

Objective: Few studies have compared fractional curve correction after long fusion between transforaminal lumbar interbody fusion (TLIF) and anterior lumbar interbody fusion (ALIF) for adult symptomatic thoracolumbar/lumbar scoliosis (ASLS). The objective of this study was to compare fractional correction, health-related quality of life (HRQL), and complications associated with L4-S1 TLIF versus those of ALIF as an operative treatment of ASLS., Methods: The authors retrospectively analyzed a prospective multicenter adult spinal deformity database. Inclusion required a fractional curve ≥ 10°, a thoracolumbar/lumbar curve ≥ 30°, index TLIF or ALIF performed at L4-5 and/or L5-S1, and a minimum 2-year follow-up. TLIF and ALIF patients were propensity matched according to the number and type of interbody fusion at L4-S1., Results: Of 135 potentially eligible consecutive patients, 106 (78.5%) achieved the minimum 2-year follow-up (mean ± SD age 60.6 ± 9.3 years, 85% women, 44.3% underwent TLIF, and 55.7% underwent ALIF). Index operations had mean ± SD 12.2 ± 3.6 posterior levels, 86.6% of patients underwent iliac fixation, 67.0% underwent TLIF/ALIF at L4-5, and 84.0% underwent TLIF/ALIF at L5-S1. Compared with TLIF patients, ALIF patients had greater cage height (10.9 ± 2.1 mm for TLIF patients vs 14.5 ± 3.0 mm for ALIF patients, p = 0.001) and lordosis (6.3° ± 1.6° for TLIF patients vs 17.0° ± 9.9° for ALIF patients, p = 0.001) and longer operative duration (6.7 ± 1.5 hours for TLIF patients vs 8.9 ± 2.5 hours for ALIF patients, p < 0.001). In all patients, final alignment improved significantly in terms of the fractional curve (20.2° ± 7.0° to 6.9° ± 5.2°), maximum coronal Cobb angle (55.0° ± 14.8° to 23.9° ± 14.3°), C7 sagittal vertical axis (5.1 ± 6.2 cm to 2.3 ± 5.4 cm), pelvic tilt (24.6° ± 8.1° to 22.7° ± 9.5°), and lumbar lordosis (32.3° ± 18.8° to 51.4° ± 14.1°) (all p < 0.05). Matched analysis demonstrated comparable fractional correction (-13.6° ± 6.7° for TLIF patients vs -13.6° ± 8.1° for ALIF patients, p = 0.982). In all patients, final HRQL improved significantly in terms of Oswestry Disability Index (ODI) score (42.4 ± 16.3 to 24.2 ± 19.9), physical component summary (PCS) score of the 36-item Short-Form Health Survey (32.6 ± 9.3 to 41.3 ± 11.7), and Scoliosis Research Society-22r score (2.9 ± 0.6 to 3.7 ± 0.7) (all p < 0.05). Matched analysis demonstrated worse ODI (30.9 ± 21.1 for TLIF patients vs 17.9 ± 17.1 for ALIF patients, p = 0.017) and PCS (38.3 ± 12.0 for TLIF patients vs 45.3 ± 10.1 for ALIF patients, p = 0.020) scores for TLIF patients at the last follow-up (despite no differences in these parameters at baseline). The rates of total complications were similar (76.6% for TLIF patients vs 71.2% for ALIF patients, p = 0.530), but significantly more TLIF patients had rod fracture (28.6% of TLIF patients vs 7.1% of ALIF patients, p = 0.036). Multiple regression analysis demonstrated that a 1-mm increase in L4-5 TLIF cage height led to a 2.2° reduction in L4 coronal tilt (p = 0.011), and a 1° increase in L5-S1 ALIF cage lordosis led to a 0.4° increase in L5-S1 segmental lordosis (p = 0.045)., Conclusions: Operative treatment of ASLS with L4-S1 TLIF versus ALIF demonstrated comparable mean fractional curve correction (66.7% vs 64.8%), despite use of significantly larger, more lordotic ALIF cages. TLIF cage height had a significant impact on leveling L4 coronal tilt, whereas ALIF cage lordosis had a significant impact on restoration of lumbosacral lordosis. The advantages of TLIF may include reduced operative duration and hospitalization; however, associated HRQL was inferior and more rod fractures were detected in the TLIF patients included in this study.

Objective: Adjacent-segment disease (ASD) requiring operative intervention is a relatively common long-term consequence of lumbar fusion surgery. Although the incidence of ASD requiring reoperation is well described for traditional posterior lumbar approaches (2.5%-3.9% per year), it remains poorly characterized for stand-alone lateral lumbar interbody fusion (LLIF). In this study, the authors report their institutional experience with ASD requiring reoperation after LLIF over an extended follow-up period of 4 years., Methods: Medical records were reviewed for 276 consecutive patients who underwent stand-alone LLIF by a single surgeon for degenerative spinal disorders. Inclusion criteria (single-stage, stand-alone LLIF without posterior supplementation, with no prior lumbar instrumentation, and a minimum of 4 years of follow-up) were met by 182 patients, who were analyzed for operative ASD incidence (per-year rate), demographics, and Oswestry Disability Index (ODI) score. Operative ASD was strictly defined as new-onset pathology following index surgery at directly adjacent levels to the prior construct. Operative, rather than symptomatic or radiographic, ASD was analyzed to provide a consistent and impactful endpoint while avoiding retrospective diagnosis., Results: The study cohort of 182 patients had an operative ASD rate of 3.3% (n = 6 procedures) over 4 years of follow-up, for an incidence on Kaplan-Meier survival analysis of 0.88% (95% CI 0.67%-1.09%) per year. In comparing patients with operative ASD with those without, there were no significant differences in mean age (53.7 vs 56.2 years), male sex (33.3% vs 44.9%), smoking status (16.7% vs 25.0%), or number of levels fused (mean 1.33 vs 1.46). The operative ASD cohort had a greater mean BMI (37.3 vs 30.2, p < 0.01). Operative ASD patients had lower baseline ODI scores (33.8 vs 48.3, p = 0.02); however, no difference was observed in ODI at 6 weeks (34.0 vs 39.0) or 3 months (16.0 vs 32.8) postoperatively., Conclusions: The incidence of ASD in LLIF for degenerative lumbar etiologies in this cohort was 0.88% (95% CI 0.67%-1.09%) per year. Meanwhile, the reported reoperation rates for ASD in posterior spinal approaches was 2.5% to 3.9% per year, which implies that LLIF may be preferable for well-selected patients.

Objective: The goal of this study was to assess the conversion rate from baseline cervical alignment to postoperative cervical deformity (CD) and the corresponding proximal junctional kyphosis (PJK) rate in patients undergoing thoracolumbar adult spinal deformity (ASD) surgery., Methods: The operative records of patients with ASD with complete radiographic data beginning at baseline up to 3 years were included. Patients with no baseline CD were postoperatively stratified by Ames CD criteria (T1 slope-cervical lordosis mismatch [TS-CL] > 20°, cervical sagittal vertical axis [cSVA] > 40 mm), where CD was defined as fulfilling one or more of the Ames criteria. Severe CD was defined as TS-CL > 30° or cSVA > 60 mm. Follow-up intervals were established after ASD surgery, with 6 weeks postoperatively defined as early; 6 weeks-1 year as intermediate; 1-2 years as late; and 2-3 years as long-term. Descriptive analyses and McNemar tests identified the CD conversion rate, PJK rate (< -10° change in uppermost instrumented vertebra and the superior endplate of the vertebra 2 levels superior to the uppermost instrumented vertebra), and specific alignment parameters that converted., Results: Two hundred sixty-six patients who underwent ASD surgery (mean age 59.7 years, 77.4% female) met the inclusion criteria; 103 of these converted postoperatively, and the remaining 163 did not meet conversion criteria. Thirty-eight patients converted to CD early, 26 converted at the intermediate time point, 29 converted late, and 10 converted in the long-term. At conversion, the early group had the highest mean TS-CL at 25.4° ± 8.5° and the highest mean cSVA at 33.6 mm-both higher than any other conversion group. The long-term group had the highest mean C2-7 angle at 19.7° and the highest rate of PJK compared to other groups (p = 0.180). The early group had the highest rate of conversion to severe CD, with 9 of 38 patients having severe TS-CL and only 1 patient per group converting to severe cSVA. Seven patients progressed from having only malaligned TS-CL at baseline (with normal cSVA) to CD with both malaligned TS-CL and cSVA by 6 weeks. Conversely, only 2 patients progressed from malaligned cSVA to both malaligned cSVA and TS-CL. By 1 year, the former number increased from 7 to 26 patients, and the latter increased from 2 to 20 patients. The revision rate was highest in the intermediate group at 48.0%, versus the early group at 19.2%, late group at 27.3%, and long-term group at 20% (p = 0.128). A higher pelvic incidence-lumbar lordosis mismatch, lower thoracic kyphosis, and a higher thoracic kyphosis apex immediately postoperatively significantly predicted earlier rather than later conversion (all p < 0.05). Baseline lumbar lordosis, pelvic tilt, and sacral slope were not significant predictors., Conclusions: Patients with ASD with normative cervical alignment who converted to CD after thoracolumbar surgery had varying radiographic findings based on timing of conversion. Although the highest number of patients converted within 6 weeks postoperatively, patients who converted in the late or long-term follow-up intervals had higher rates of concurrent PJK and greater radiographic progression.

Objective: Cervical deformity (CD) patients have severe disability and poor health status. However, little is known about how patients with rigid CD compare with those with flexible CD. The main objectives of this study were to 1) assess whether patients with rigid CD have worse baseline alignment and therefore require more aggressive surgical corrections and 2) determine whether patients with rigid CD have similar postoperative outcomes as those with flexible CD., Methods: This is a retrospective review of a prospective, multicenter CD database. Rigid CD was defined as cervical lordosis (CL) change < 10° between flexion and extension radiographs, and flexible CD was defined as a CL change ≥ 10°. Patients with rigid CD were compared with those with flexible CD in terms of cervical alignment and health-related quality of life (HRQOL) at baseline and at multiple postoperative time points. The patients were also compared in terms of surgical and intraoperative factors such as operative time, blood loss, and number of levels fused., Results: A total of 127 patients met inclusion criteria (32 with rigid and 95 with flexible CD, 63.4% of whom were females; mean age 60.8 years; mean BMI 27.4); 47.2% of cases were revisions. Rigid CD was associated with worse preoperative alignment in terms of T1 slope minus CL, T1 slope, C2-7 sagittal vertical axis (cSVA), and C2 slope (C2S; all p < 0.05). Postoperatively, patients with rigid CD had an increased mean C2S (29.1° vs 22.2°) at 3 months and increased cSVA (47.1 mm vs 37.5 mm) at 1 year (p < 0.05) compared with those with flexible CD. Patients with rigid CD had more posterior levels fused (9.5 vs 6.3), fewer anterior levels fused (1 vs 2.0), greater blood loss (1036.7 mL vs 698.5 mL), more 3-column osteotomies (40.6% vs 12.6%), greater total osteotomy grade (6.5 vs 4.5), and mean osteotomy grade per level (3.3 vs 2.1) (p < 0.05 for all). There were no significant differences in baseline HRQOL scores, the rate of distal junctional kyphosis, or major/minor complications between patients with rigid and flexible CD. Both rigid and flexible CD patients reported significant improvements from baseline to 1 year according to the numeric rating scale for the neck (-2.4 and -2.7, respectively), Neck Disability Index (-8.4 and -13.3, respectively), modified Japanese Orthopaedic Association score (0.1 and 0.6), and EQ-5D (0.01 and 0.05) (p < 0.05). However, HRQOL changes from baseline to 1 year did not differ between rigid and flexible CD patients., Conclusions: Patients with rigid CD have worse baseline cervical malalignment compared with those with flexible CD but do not significantly differ in terms of baseline disability. Rigid CD was associated with more invasive surgery and more aggressive corrections, resulting in increased operative time and blood loss. Despite more extensive surgeries, rigid CD patients had equivalent improvements in HRQOL compared with flexible CD patients. This study quantifies the importance of analyzing flexion-extension images, creating a prognostic tool for surgeons planning CD correction, and counseling patients who are considering CD surgery.

Objective: The impact of global coronal malalignment (GCM; C7 plumb line-midsacral offset) on adult spinal deformity (ASD) treatment outcomes is unclear. Here, the authors' primary objective was to assess surgical outcomes and complications in patients with severe GCM, with a secondary aim of investigating potential surgical target coronal thresholds for optimal outcomes., Methods: This is a retrospective analysis of a prospective multicenter database. Operative patients with severe GCM (≥ 1 SD above the mean) and a minimum 2-year follow-up were identified. Demographic, surgical, radiographic, health-related quality of life (HRQOL), and complications data were analyzed., Results: Of 691 potentially eligible operative patients (mean GCM 4 ± 3 cm), 80 met the criteria for severe GCM ≥ 7 cm. Of these, 62 (78%; mean age 63.7 ± 10.7 years, 81% women) had a minimum 2-year follow-up (mean follow-up 3.3 ± 1.1 years). The mean ASD-Frailty Index was 3.9 ± 1.5 (frail), 50% had undergone prior fusion, and 81% had concurrent severe sagittal spinopelvic deformity with GCM and C7-S1 sagittal vertical axis (SVA) positively correlated (r = 0.313, p = 0.015). Surgical characteristics included posterior-only (58%) versus anterior-posterior (42%) approach, mean fusion of 13.2 ± 3.8 levels, iliac fixation (90%), 3-column osteotomy (36%), operative duration of 8.3 ± 3.0 hours, and estimated blood loss of 2.3 ± 1.7 L. Final alignment and HRQOL significantly improved (p < 0.01): GCM, 11 to 4 cm; maximum coronal Cobb angle, 43° to 20°; SVA, 13 to 4 cm; pelvic tilt, 29° to 23°; pelvic incidence-lumbar lordosis mismatch, 31° to 5°; Oswestry Disability Index, 51 to 37; physical component summary of SF-36 (PCS), 29 to 37; 22-Item Scoliosis Research Society Patient Questionnaire (SRS-22r) Total, 2.6 to 3.5; and numeric rating scale score for back and leg pain, 7 to 4 and 5 to 3, respectively. Residual GCM ≥ 3 cm was associated with worse SRS-22r Appearance (p = 0.04) and SRS-22r Satisfaction (p = 0.02). The minimal clinically important difference and/or substantial clinical benefit (MCID/SCB) was met in 43%-83% (highest for SRS-22r Appearance [MCID 83%] and PCS [SCB 53%]). The severity of baseline GCM (≥ 2 SD above the mean) significantly impacted postoperative SRS-22r Satisfaction and MCID/SCB improvement for PCS. No significant partial correlations were demonstrated between GCM or SVA correction and HRQOL improvement. There were 89 total complications (34 minor and 55 major), 45 (73%) patients with ≥ 1 complication (most commonly rod fracture [19%] and proximal junctional kyphosis [PJK; 18%]), and 34 reoperations in 22 (35%) patients (most commonly for rod fracture and PJK)., Conclusions: Study results demonstrated that ASD surgery in patients with substantial GCM was associated with significant radiographic and HRQOL improvement despite high complication rates. MCID improvement was highest for SRS-22r Appearance/Self-Image. A residual GCM ≥ 3 cm was associated with a worse outcome, suggesting a potential coronal realignment target threshold to assist surgical planning.

Objective: Stand-alone lateral lumbar interbody fusion (LLIF) is a useful minimally invasive approach for select spinal disorders, but implant subsidence may occur in up to 30% of patients. Previous studies have suggested that wider implants reduce the subsidence rate. This study aimed to evaluate whether a mismatch of the endplate and implant area can predict the rate and grade of implant subsidence., Methods: The authors conducted a retrospective review of prospectively collected data on consecutive patients who underwent stand-alone LLIF between July 2008 and June 2015; 297 patients (623 surgical levels) met inclusion criteria. Imaging studies were examined to grade graft subsidence according to Marchi criteria. Thirty patients had radiographic evidence of implant subsidence. The endplates above and below the implant were measured., Results: A total of 30 patients with implant subsidence were identified. Of these patients, 6 had Marchi grade 0, 4 had grade I, 12 had grade II, and 8 had grade III implant subsidence. There was no statistically significant correlation between the endplate-implant area mismatch and subsidence grade or incidence. There was also no correlation between endplate-implant width and length mismatch and subsidence grade or incidence. However, there was a strong correlation between the usage of the 18-mm-wide implants and the development of higher-grade subsidence (p = 0.002) necessitating surgery. There was no significant association between the degree of mismatch or Marchi subsidence grade and the presence of postoperative radiculopathy. Of the 8 patients with 18-mm implants demonstrating radiographic subsidence, 5 (62.5%) required reoperation. Of the 22 patients with 22-mm implants demonstrating radiographic subsidence, 13 (59.1%) required reoperation., Conclusions: There was no correlation between endplate-implant area, width, or length mismatch and Marchi subsidence grade for stand-alone LLIF. There was also no correlation between either endplate-implant mismatch or Marchi subsidence grade and postoperative radiculopathy. The data do suggest that the use of 18-mm-wide implants in stand-alone LLIF may increase the risk of developing high-grade subsidence necessitating reoperation compared to the use of 22-mm-wide implants.

Objective: Optimal patient selection for upper-thoracic (UT) versus lower-thoracic (LT) fusion during adult spinal deformity (ASD) correction is challenging. Radiographic and clinical outcomes following UT versus LT fusion remain incompletely understood. The purposes of this study were: 1) to evaluate demographic, radiographic, and surgical characteristics associated with choice of UT versus LT fusion endpoint; and 2) to evaluate differences in radiographic, clinical, and health-related quality of life (HRQOL) outcomes following UT versus LT fusion for ASD., Methods: Retrospective review of a prospectively collected multicenter ASD database was performed. Patients with ASD who underwent fusion from the sacrum/ilium to the LT (T9-L1) or UT (T1-6) spine were compared for demographic, radiographic, and surgical characteristics. Outcomes including proximal junctional kyphosis (PJK), reoperation, rod fracture, pseudarthrosis, overall complications, 2-year change in alignment parameters, and 2-year HRQOL metrics (Lumbar Stiffness Disability Index, Scoliosis Research Society-22r questionnaire, Oswestry Disability Index) were compared after controlling for confounding factors via multivariate analysis., Results: Three hundred three patients (169 LT, 134 UT) were evaluated. Independent predictors of UT fusion included greater thoracic kyphosis (odds ratio [OR] 0.97 per degree, p = 0.0098), greater coronal Cobb angle (OR 1.06 per degree, p < 0.0001), and performance of a 3-column osteotomy (3-CO; OR 2.39, p = 0.0351). While associated with longer operative times (ratio 1.13, p < 0.0001) and greater estimated blood loss (ratio 1.31, p = 0.0018), UT fusions resulted in greater sagittal vertical axis improvement (-59.5 vs -41.0 mm, p = 0.0035) and lower PJK rates (OR 0.49, p = 0.0457). No significant differences in postoperative HRQOL measures, reoperation, or overall complication rates were detected between groups (all p > 0.1)., Conclusions: Greater deformity and need for 3-CO increased the likelihood of UT fusion. Despite longer operative times and greater blood loss, UT fusions resulted in better sagittal correction and lower 2-year PJK rates following surgery for ASD. While continued surveillance is necessary, this information may inform patient counseling and surgical decision-making.

Objective: Obesity, a condition that is increasing in prevalence in the United States, has previously been associated with poorer outcomes following deformity surgery, including higher rates of perioperative complications such as deep and superficial infections. To date, however, no study has examined the relationship between preoperative BMI and outcomes of deformity surgery as measured by spine parameters such as the sagittal vertical axis (SVA), as well as health-related quality of life (HRQoL) measures such as the Oswestry Disability Index (ODI) and Scoliosis Research Society-22 patient questionnaire (SRS-22). To this end, the authors sought to clarify the relationship between BMI and postoperative change in SVA as well as HRQoL outcomes., Methods: The authors performed a retrospective review of a prospectively managed multicenter adult spinal deformity database collected and maintained by the International Spine Study Group (ISSG) between 2009 and 2014. The primary independent variable considered was preoperative BMI. The primary outcome was the change in SVA at 1 year after deformity surgery. Postoperative ODI and SRS-22 outcome measures were evaluated as secondary outcomes. Generalized linear models were used to model the primary and secondary outcomes at 1 year as a function of BMI at baseline, while adjusting for potential measured confounders., Results: Increasing BMI (compared to BMI < 18) was not associated with change of SVA at 1 year postsurgery. However, BMIs in the obese range of 30 to 34.9 kg/m2, compared to BMI < 18 at baseline, were associated with poorer outcomes as measured by the SRS-22 score (estimated change -0.47, 95% CI -0.93 to -0.01, p = 0.04). While BMIs > 30 appeared to be associated with poorer outcomes as determined by the ODI, this correlation did not reach statistical significance., Conclusions: Baseline BMI did not affect the achievable SVA at 1 year postsurgery. Further studies should evaluate whether even in the absence of a change in SVA, baseline BMIs in the obese range are associated with worsened HRQoL outcomes after spinal surgery.

Objective: The Clinician and Group Consumer Assessment of Healthcare Providers and Systems (CG-CAHPS) is a standardized patient experience survey that is used to evaluate the quality of care delivered by physicians. The authors sought to determine which factors influenced CG-CAHPS scores for spine surgery, and compare them to their cranial-focused cohorts., Methods: A retrospective study of prospectively obtained data was performed to evaluate CG-CAHPS scores. Between May 2013 and May 2017, all patients 18 years of age or older with an outpatient encounter with a neurosurgeon (5 spine-focused neurosurgeons and 20 cranial-focused neurosurgeons) received a CG-CAHPS survey. Three domains were assessed: overall physician rating, likelihood to recommend, and physician communication. Statistical analyses were performed using chi-square tests., Results: Seven thousand four hundred eighty-five patient surveys (2319 spine and 5166 cranial) were collected from patients presenting to the outpatient offices of an attending neurosurgeon. Analysis of the overall physician rating showed that 81.1% of spine neurosurgeons received a "top-box" score (answers of "yes, definitely"), whereas 86.2% of cranial neurosurgeons received a top-box response (p < 0.001). A similar difference was observed with the domains of "likelihood to recommend" and "physician communication." Overall physician rating was also significantly influenced by the general and mental health of the patients surveyed (p < 0.001). For spine surgeons seeing patients at more than one facility, the scores with respect to location were also significantly different in all domains for each individual provider (p < 0.001)., Conclusions: Overall, spine-focused neurosurgeon ratings differed significantly from those of cranial-focused neurosurgical subspecialty providers. Office location also affected provider ratings for spine neurosurgeons. These results suggest that physician ratings obtained via patient experience surveys may be representative of factors aside from just the quality of physician care provided. This information should be considered as payers, government, and health systems design performance programs based on patient experience scores.

OBJECTIVEElderly patients, often presenting with multiple medical comorbidities, are touted to be at an increased risk of peri- and postoperative complications following spine surgery. Various minimally invasive surgical techniques have been developed and employed to treat an array of spinal conditions while minimizing complications. Lateral lumbar interbody fusion (LLIF) is one such approach. The authors describe clinical outcomes in patients over the age of 70 years following stand-alone LLIF.METHODSA retrospective query of a prospectively maintained database was performed for patients over the age of 70 years who underwent stand-alone LLIF. Patients with posterior segmental fixation and/or fusion were excluded. The preoperative and postoperative values for the Oswestry Disability Index (ODI) were analyzed to compare outcomes after intervention. Femoral neck t-scores were acquired from bone density scans and correlated with the incidence of graft subsidence.RESULTSAmong the study cohort of 55 patients, the median age at the time of surgery was 74 years (range 70-87 years). Seventeen patients had at least 3 medical comorbidities at surgery. Twenty-three patients underwent a 1-level, 14 a 2-level, and 18 patients a 3-level or greater stand-alone lateral fusion. The median estimated blood loss was 25 ml (range 5-280 ml). No statistically significant relationship was detected between volume of blood loss and the number of operative levels. The median length of hospital stay was 2 days (range 1-4 days). No statistically significant relationship was observed between the length of hospital stay and age at the time of surgery. There was one intraoperative death secondary to cardiac arrest, with a mortality rate of 1.8%. One patient developed a transient femoral nerve injury. Five patients with symptomatic graft subsidence subsequently underwent posterior instrumentation. A lower femoral neck t-score < -1.0 correlated with a higher incidence of graft subsidence (p = 0.006). The mean ODI score 1 year postoperatively of 31.1 was significantly (p = 0.003) less than the mean preoperative ODI score of 46.2.CONCLUSIONSStand-alone LLIF can be safely and effectively performed in the elderly population. Careful evaluation of preoperative bone density parameters should be employed to minimize risk of subsidence and need for additional surgery. Despite an association with increased comorbidities, age alone should not be a deterrent when considering stand-alone LLIF in the elderly population.

Objective: Currently, there is a lack of research assessing residents' operative experience and caseload variability. The current study utilizes data from the Accreditation Council for Graduate Medical Education (ACGME) case log system to analyze national trends in neurosurgical residents' exposure to adult spinal procedures., Methods: Prospectively populated ACGME resident case logs from 2013 to 2017 were retrospectively reviewed. The reported number of spinal procedures was compared to the ACGME minimum requirements for each surgical category pertaining to adult spine surgery. A linear regression analysis was conducted to identify changes in operative caseload by residents graduating during the study period, as well as a one-sample t-test using IBM SPSS software to compare the mean number of procedures in each surgical category to the ACGME required minimums., Results: A mean of 427.42 total spinal procedures were performed throughout residency training for each of the 877 residents graduating between 2013 and 2017. The mean number of procedures completed by graduating residents increased by 19.96 (r 2 = 0.95) cases per year. The number of cases in every procedural subspecialty, besides peripheral nerve operations, significantly increased during this time. The two procedural categories with the largest changes were anterior and posterior cervical approaches for decompression/stabilization, which increased by 8.78% per year (r 2 = 0.95) and 9.04% per year (r 2 = 0.95), respectively. There was also a trend of increasing cases logged for lead resident surgeons and a decline in cases logged for senior resident surgeons. Residents' mean caseloads during residency were found to be vastly greater than the ACGME required minimums: residents performed at least twice as many procedures as the required minimums in every surgical category., Conclusions: Graduating neurosurgical residents reported increasing case volumes for adult spinal cases during this 5-year interval. An increase in logged cases for lead resident surgeons as opposed to senior resident surgeons indicates that residents were logging more cases in which they had a more critical role in the procedure. Moreover, the average resident was noted to perform more than twice the number of procedures required by the ACGME in every surgical category, indicating that neurosurgical residents are getting greater exposure to spine surgery than expected. Given the known correlation between case volume and improved surgical outcomes, this data demonstrates each graduating neurosurgical residency class experiences an augmented training in spine surgery.

OBJECTIVE Given the recent shift in health care toward quality reporting requirements and a greater emphasis on a cost-quality approach, patient stratification with respect to long-term outcomes and the use of health care resources is of increasing value. Stratification tools may be effective if they are simple and evidence based. The authors hypothesize that preoperative patient-reported activity levels might independently predict postoperative outcomes in patients with adult spinal deformity. METHODS This is a retrospective cohort. A total of 575 patients in a prospective adult spinal deformity surgical database were identified with complete data regarding the preoperative level of activity. Answers to question 5 of the Scoliosis Research Society-22r Patient Questionnaire (SRS-22r) were used to stratify patients into active and inactive groups. Outcomes were length of hospital stay (LOS), level of activity, and reaching the minimum clinically important difference (MCID) for SRS-22r domains and the Physical Component Summary (PCS) of the SF-36 at 2 years postoperatively. The 2 groups were compared with respect to several potential confounders. Covariates with p < 0.1 were controlled for. The impact of activity on LOS was assessed using multivariate negative binomial regression analysis. Multivariate logistic regression models additionally controlling for the respective baseline health-related quality of life (HRQOL) scores were used to assess the association between preoperative activity levels and reaching the MCID at 2 years postoperatively. RESULTS A total of 420 (73%) of the 575 patients who met the inclusion criteria had complete data at 2 years postoperatively. The inactive group was more likely to be significantly older, have a higher Charlson Comorbidity Index, worse baseline radiographic deformity, and greater correction of most radiographic parameters. After controlling for possible confounders, the active group had a significantly shorter LOS (incidence risk ratio 0.91, p = 0.043). After adding respective baseline HRQOL scores to the models, active patients were significantly more likely to reach the MCID for the SRS-22r pain domain (OR 1.72, p = 0.026) and PCS (OR 1.94, p = 0.013). Active patients were also significantly more likely to be active at 2 years postoperatively on multivariate analysis (OR 8.94, p < 0.001). CONCLUSIONS The authors' results show that patients who belong to the inactive group are likely to have a longer LOS and lower odds of reaching the MCID in HRQOL or being active at 2 years postoperatively. Inquiring about patients' preoperative activity levels might be a reliable and simple stratification tool in terms of long- and short-term outcomes in ASD patients.

OBJECTIVE Previous studies have demonstrated the efficacy of infection prevention protocols in reducing infection rates. This study investigated the effects of the development and implementation of an infection prevention protocol that was augmented by increased physician awareness of spinal fusion surgical site infection (SSI) rates and resultant cost savings. METHODS A cohort clinical investigation over a 10-year period was performed at a single tertiary spine care academic institution. Preoperative infection control measures (chlorohexidine gluconate bathing, Staphylococcus aureus nasal screening and decolonization) followed by postoperative infection control measures (surgical dressing care) were implemented. After the implementation of these infection control measures, an awareness intervention was instituted in which all attending and resident neurosurgeons were informed of their individual, independently adjudicated spinal fusion surgery infection rates and rankings among their peers. During the course of these interventions, the overall infection rate was tracked as well as the rates for those neurosurgeons who complied with the preoperative and postoperative infection control measures (protocol group) and those who did not (control group). RESULTS With the implementation of postoperative surgical dressing infection control measures and physician awareness, the postoperative spine surgery infection rate decreased by 45% from 3.8% to 2.1% (risk ratio 0.55; 95% CI 0.32-0.93; p = 0.03) for those in the protocol cohort, resulting in an estimated annual cost savings of $291,000. This reduction in infection rate was not observed for neurosurgeons in the control group, although the overall infection rate among all neurosurgeons decreased by 54% from 3.3% to 1.5% (risk ratio 0.46; 95% CI 0.28-0.73; p = 0.0013). CONCLUSIONS A novel paradigm for spine surgery infection control combined with physician awareness methods resulted in significantly decreased SSI rates and an associated cost reduction. Thus, information sharing and physician engagement as a supplement to formal infection control measures result in improvements in surgical outcomes and costs.

OBJECTIVE Lateral lumbar interbody fusion (LLIF) is a less invasive surgical option commonly used for a variety of spinal conditions, including in high-risk patient populations. LLIF is often performed as a stand-alone procedure, and may be complicated by graft subsidence, the clinical ramifications of which remain unclear. The aim of this study was to characterize further the sequelae of graft subsidence following stand-alone LLIF. METHODS A retrospective review of prospectively collected data was conducted on consecutive patients who underwent stand-alone LLIF between July 2008 and June 2015; 297 patients (623 levels) met inclusion criteria. Imaging studies were examined to grade graft subsidence according to Marchi criteria, and compared between those who required revision surgery and those who did not. Additional variables recorded included levels fused, DEXA (dual-energy x-ray absorptiometry) T-score, body mass index, and routine demographic information. The data were analyzed using the Student t-test, chi-square analysis, and logistic regression analysis to identify potential confounding factors. RESULTS Of 297 patients, 34 (11.4%) had radiographic evidence of subsidence and 18 (6.1%) required revision surgery. The median subsidence grade for patients requiring revision surgery was 2.5, compared with 1 for those who did not. Chi-square analysis revealed a significantly higher incidence of revision surgery in patients with high-grade subsidence compared with those with low-grade subsidence. Seven of 18 patients (38.9%) requiring revision surgery suffered a vertebral body fracture. High-grade subsidence was a significant predictor of the need for revision surgery (p < 0.05; OR 12, 95% CI 1.29-13.6), whereas age, body mass index, T-score, and number of levels fused were not. This relationship remained significant despite adjustment for the other variables (OR 14.4; 95% CI 1.30-15.9). CONCLUSIONS In this series, more than half of the patients who developed graft subsidence following stand-alone LLIF required revision surgery. When evaluating patients for LLIF, supplemental instrumentation should be considered during the index surgery in patients with a significant risk of graft subsidence.

OBJECTIVE Using 2 complication-reporting methods, the authors investigated the incidence of major medical complications and mortality in elderly patients after surgery for adult spinal deformity (ASD) during a 2-year follow-up period. METHODS The authors queried a multicenter, prospective, surgeon-maintained database (SMD) to identify patients 65 years or older who underwent surgical correction of ASD from 2008 through 2014 and had a minimum 2 years of follow-up (n = 153). They also queried a Centers for Medicare & Medicaid Services claims database (MCD) for patients 65 years or older who underwent fusion of 8 or more vertebral levels from 2005 through 2012 (n = 3366). They calculated cumulative rates of the following complications during the first 6 weeks after surgery: cerebrovascular accident, congestive heart failure, deep venous thrombosis, myocardial infarction, pneumonia, and pulmonary embolism. Significance was set at p < 0.05. RESULTS During the perioperative period, rates of major medical complications were 5.9% for pneumonia, 4.1% for deep venous thrombosis, 3.2% for pulmonary embolism, 2.1% for cerebrovascular accident, 1.8% for myocardial infarction, and 1.0% for congestive heart failure. Mortality rates were 0.9% at 6 weeks and 1.8% at 2 years. When comparing the SMD with the MCD, there were no significant differences in the perioperative rates of major medical complications except pneumonia. Furthermore, there were no significant intergroup differences in the mortality rates at 6 weeks or 2 years. The SMD provided greater detail with respect to deformity characteristics and surgical variables than the MCD. CONCLUSIONS The incidence of most major medical complications in the elderly after surgery for ASD was similar between the SMD and the MCD and ranged from 1% for congestive heart failure to 5.9% for pneumonia. These complications data can be valuable for preoperative patient counseling and informed consent.

OBJECTIVE Surgical site infections (SSIs) are a major source of morbidity after spinal surgery. Several recent studies have described the finding that applying vancomycin powder to the surgical bed may reduce the incidence of SSI. However, applying vancomycin in high concentrations has been shown in vitro to inhibit osteoblast proliferation and to induce cell death. Vancomycin may have a deleterious effect on dural healing after repair of an intentional or unintentional durotomy. This study was therefore undertaken to assess the effect of different concentrations of vancomycin on a human dura mater cell culture. METHODS Human dura intended for disposal after decompressive craniectomy was harvested. Explant primary cultures and subcultures were subsequently performed. Cells were characterized through common staining and immunohistochemistry. A growth curve was performed to assess the effect of different concentrations of vancomycin (40, 400, and 4000 μg/ml) on cell count. The effect of vancomycin on cellular shape, intercellular arrangement, and viability was also evaluated. RESULTS All dural tissue samples successfully developed into fusiform cells, demonstrating pseudopod projections and spindle formation. The cells demonstrated vimentin positivity and also had typical features of fibroblasts. When applied to the cultures, the highest dose of vancomycin induced generalized cell death within 24 hours. The mean (± SD) cell counts for control, 40, 400, and 4000 μg/ml were 38.72 ± 15.93, 36.28 ± 22.87, 19.48 ± 6.53, and 4.07 ± 9.66, respectively (p < 0.0001, ANOVA). Compared with controls, vancomycin-exposed cells histologically demonstrated a smaller cytoplasm and decreased pseudopodia formation resulting in the inhibition of normal spindle intercellular arrangement. CONCLUSIONS When vancomycin powder is applied locally, dural cells are exposed to a concentration several times greater than when delivered systemically. In this in vitro model, vancomycin induced dural cell death, inhibited growth, and altered cellular morphology in a concentration-dependent fashion. Defining a safe vancomycin concentration that is both bactericidal and also does not inhibit normal dural healing is necessary.

OBJECTIVE Although multiple reports have documented significant benefit from surgical treatment of adult spinal deformity (ASD), these procedures can have high complication rates. Previously reported complications rates associated with ASD surgery are limited by retrospective design, single-surgeon or single-center cohorts, lack of rigorous data on complications, and/or limited follow-up. Accurate definition of complications associated with ASD surgery is important and may serve as a resource for patient counseling and efforts to improve the safety of patient care. The authors conducted a study to prospectively assess the rates of complications associated with ASD surgery with a minimum 2-year follow-up based on a multicenter study design that incorporated standardized data-collection forms, on-site study coordinators, and regular auditing of data to help ensure complete and accurate reporting of complications. In addition, they report age stratification of complication rates and provide a general assessment of factors that may be associated with the occurrence of complications. METHODS As part of a prospective, multicenter ASD database, standardized forms were used to collect data on surgery-related complications. On-site coordinators and central auditing helped ensure complete capture of complication data. Inclusion criteria were age older than 18 years, ASD, and plan for operative treatment. Complications were classified as perioperative (within 6 weeks of surgery) or delayed (between 6 weeks after surgery and time of last follow-up), and as minor or major. The primary focus for analyses was on patients who reached a minimum follow-up of 2 years. RESULTS Of 346 patients who met the inclusion criteria, 291 (84%) had a minimum 2-year follow-up (mean 2.1 years); their mean age was 56.2 years. The vast majority (99%) had treatment including a posterior procedure, 25% had an anterior procedure, and 19% had a 3-column osteotomy. At least 1 revision was required in 82 patients (28.2%). A total of 270 perioperative complications (145 minor; 125 major) were reported, with 152 patients (52.2%) affected, and a total of 199 delayed complications (62 minor; 137 major) were reported, with 124 patients (42.6%) affected. Overall, 469 complications (207 minor; 262 major) were documented, with 203 patients (69.8%) affected. The most common complication categories included implant related, radiographic, neurological, operative, cardiopulmonary, and infection. Higher complication rates were associated with older age (p = 0.009), greater body mass index (p ≤ 0.031), increased comorbidities (p ≤ 0.007), previous spine fusion (p = 0.029), and 3-column osteotomies (p = 0.036). Cases in which 2-year follow-up was not achieved included 2 perioperative mortalities (pulmonary embolus and inferior vena cava injury). CONCLUSIONS This study provides an assessment of complications associated with ASD surgery based on a prospective, multicenter design and with a minimum 2-year follow-up. Although the overall complication rates were high, in interpreting these findings, it is important to recognize that not all complications are equally impactful. This study represents one of the most complete and detailed reports of perioperative and delayed complications associated with ASD surgery to date. These findings may prove useful for treatment planning, patient counseling, benchmarking of complication rates, and efforts to improve the safety and cost-effectiveness of patient care.

High-grade spinal cord gliomas are rare and carry a poor prognosis. A number of treatment modalities exist for spinal cord gliomas, but no consensus exists regarding their management. Cordectomy represents a possible option for treating these lesions; however, few cases have been reported in adults, and none have been reported in the pediatric population. The authors describe the use of cordectomy for the treatment of a high-grade spinal glioma in a 9-year-old boy who remains cancer free 14 years following his initial presentation.

OBJECT Regional cervical sagittal alignment (C2-7 sagittal vertical axis [SVA]) has been shown to correlate with health-related quality of life (HRQOL). The study objective was to examine the relationship between cervical and thoracolumbar alignment parameters with HRQOL among patients with operative and nonoperative adult thoracolumbar deformity. METHODS This is a multicenter prospective data collection of consecutive patients with adult thoracolumbar spinal deformity. Clinical measures of disability included the Oswestry Disability Index (ODI), Scoliosis Research Society-22 Patient Questionnaire (SRS-22), and 36-Item Short-Form Health Survey (SF-36). Cervical radiographic parameters were correlated with global sagittal parameters within the nonoperative and operative cohorts. A partial correlation analysis was performed controlling for C-7 SVA. The operative group was subanalyzed by the magnitude of global deformity (C-7 SVA ≥ 5 cm vs < 5 cm). RESULTS A total of 318 patients were included (186 operative and 132 nonoperative). The mean age was 55.4 ± 14.9 years. Operative patients had significantly worse baseline HRQOL and significantly larger C-7 SVA, pelvic tilt (PT), mismatch between pelvic incidence and lumbar lordosis (PI-LL), and C2-7 SVA. The operative patients with baseline C-7 SVA ≥ 5 cm had significantly larger C2-7 lordosis (CL), C2-7 SVA, C-7 SVA, PI-LL, and PT than patients with a normal C-7 SVA. For all patients, baseline C2-7 SVA and CL significantly correlated with baseline ODI, Physical Component Summary (PCS), SRS Activity domain, and SRS Appearance domain. Baseline C2-7 SVA also correlated with SRS Pain and SRS Total. For the operative patients with baseline C-7 SVA ≥ 5 cm, the 2-year C2-7 SVA significantly correlated with 2-year Mental Component Summary, SRS Mental, SRS Satisfaction, and decreases in ODI. Decreases in C2-7 SVA at 2 years significantly correlated with lower ODI at 2 years. Using partial correlations while controlling for C-7 SVA, the C2-7 SVA correlated significantly with baseline ODI (r = 0.211, p = 0.002), PCS (r = -0.178, p = 0.009), and SRS Activity (r = -0.145, p = 0.034) for the entire cohort. In the subset of operative patients with larger thoracolumbar deformities, the change in C2-7 SVA correlated with change in ODI (r = -0.311, p = 0.03). CONCLUSIONS Changes in cervical lordosis correlate to HRQOL improvements in thoracolumbar deformity patients at 2-year follow-up. Regional cervical sagittal parameters such as CL and C2-7 SVA are correlated with clinical measures of regional disability and health status in patients with adult thoracolumbar scoliosis. This effect may be direct or a reciprocal effect of the underlying global deformities on regional cervical alignment. However, the partial correlation analysis, controlling for the magnitude of the thoracolumbar deformity, suggests that there is a direct effect of cervical alignment on health measures. Improvements in regional cervical alignment postoperatively correlated positively with improved HRQOL.

Object: Sexual function is an often-overlooked aspect of health-related quality of life among older adults treated for spinal deformity. The authors' objective was to assess sexual function among older adults following thoracolumbar fusion with pelvic fixation for spinal deformity., Methods: This was a retrospective review of consecutive older adults (≥50 years) treated with posterior thoracolumbar instrumentation (including pelvic fixation) for spinal deformity and with a minimum 18-month follow-up. Patients completed the Changes in Sexual Function Questionnaire-14 (CSFQ-14), Oswestry Disability Index (ODI), and 12-Item Short-Form Health Survey (SF-12)., Results: Sixty-two patients (45 women and 17 men) with a mean age of 70 years (range 50-83 years) met the inclusion criteria. Eight women did not complete all questionnaires and were excluded from the subanalysis. The mean number of instrumented levels was 9.8 (range 6-18), and the mean follow-up was 36 months (range 19-69 months). Based on the CSFQ-14, 13 patients (24%) had normal sexual function, and 8 (15%), 10 (19%), and 23 (42%) had mild, moderate, and severe dysfunction, respectively. Thirty-nine percent of patients reporting severe sexual dysfunction did not have available partners-23% because of a partner's death and 16% because of a partner's illness)-or had significant medical comorbidities of their own (48%). Thirty-nine percent of assessed patients had either no or only mild sexual dysfunction. Patients with minimal or mild disability tended to have no or mild sexual dysfunction., Conclusions: The authors of this study assessed sexual function in older adults following surgical correction of spinal deformity that included posterior instrumented fusion and iliac bolts. Nearly 40% of assessed patients had either no or only mild sexual dysfunction, suggesting that despite an older age and extensive spinopelvic instrumentation, it remains very possible to maintain or achieve satisfactory sexual function.

Objective: The originally described technique of atlantoaxial stabilization using C-1 lateral mass and C-2 pars screws includes a C-2 neurectomy to provide adequate hemostasis and visualization for screw placement, enable adequate joint decortication and arthrodesis, and prevent new-onset postoperative C-2 neuralgia. However, inclusion of a C-2 neurectomy for this procedure remains controversial, likely due in part to a lack of studies that have specifically addressed whether it affects patient outcome. The authors' objective was to assess the surgical and clinical impact of routine C-2 neurectomy performed with C1-2 segmental instrumented arthrodesis in a consecutive series of elderly patients with C1-2 instability., Methods: Forty-four consecutive patients (mean age 71 years) underwent C1-2 instrumented fusion, including C-1 lateral mass screw insertion. Bilateral C-2 neurectomies were performed. Standardized clinical assessments were performed both pre- and postoperatively. Numbness or discomfort in a C-2 distribution was documented at follow-up. Fusion was assessed using the Lenke fusion grade., Results: Among all 44 patients, mean blood loss was 200 ml (range 100-350 ml) and mean operative time was 129 minutes (range 87-240 minutes). There were no intraoperative complications, and no patients reported new postoperative onset or worsening of C-2 neuralgia postoperatively. Outcomes for the 30 patients with a minimum 13-month follow-up (range 13-72 months) were assessed. At a mean follow-up of 36 months, Nurick grade and pain numeric rating scale scores improved from 3.7 to 1.0 (p < 0.001) and 9.4 to 0.6 (p < 0.001), respectively. The mean postoperative Neck Disability Index score was 7.3%. The fusion rate was 97%, and the patient satisfaction rate was 93%. All 24 patients with preoperative occipital neuralgia reported relief. Seventeen patients noticed C-2 distribution numbness only during examination in the clinic, and 2 patients reported C-2 numbness, but it did not affect their daily function., Conclusions: In this series of C1-2 instrumented arthrodesis in elderly patients, excellent fusion rates were achieved, and patient satisfaction was not negatively affected by C-2 neurectomy. In the authors' experience, C-2 neurectomy enhanced surgical exposure of the C1-2 joint, thereby facilitating hemostasis, placement of instrumentation, and decortication of the joint space for arthrodesis. Importantly, with C-2 neurectomy in the present series, no cases of new onset postoperative C-2 neuralgia occurred, in contrast to a growing number of reports in the literature documenting new-onset C-2 neuralgia without C-2 neurectomy. On the contrary, 80% of patients in the present series had preoperative occipital neuralgia and in all of these patients this neuralgia was relieved following C1-2 instrumented arthrodesis with C-2 neurectomy.

Object: This is a retrospective review of 10,242 adults with degenerative spondylolisthesis (DS) and isthmic spondylolisthesis (IS) from the morbidity and mortality (M&M) index of the Scoliosis Research Society (SRS). This database was reviewed to assess complication incidence, and to identify factors that were associated with increased complication rates., Methods: The SRS M&M database was queried to identify cases of DS and IS treated between 2004 and 2007. Complications were identified and analyzed based on age, surgical approach, spondylolisthesis type/grade, and history of previous surgery. Age was stratified into 2 categories: > 65 years and ≤ 65 years. Surgical approach was stratified into the following categories: decompression without fusion, anterior, anterior/posterior, posterior without instrumentation, posterior with instrumentation, and interbody fusion. Spondylolisthesis grades were divided into low-grade (Meyerding I and II) versus high-grade (Meyerding III, IV, and V) groups. Both univariate and multivariate analyses were performed., Results: In the 10,242 cases of DS and IS reported, there were 945 complications (9.2%) in 813 patients (7.9%). The most common complications were dural tears, wound infections, implant complications, and neurological complications (range 0.7%-2.1%). The mortality rate was 0.1%. Diagnosis of DS had a significantly higher complication rate (8.5%) when compared with IS (6.6%; p = 0.002). High-grade spondylolisthesis correlated strongly with a higher complication rate (22.9% vs 8.3%, p < 0.0001). Age > 65 years was associated with a significantly higher complication rate (p = 0.02). History of previous surgery and surgical approach were not significantly associated with higher complication rates. On multivariate analysis, only the grade of spondylolisthesis (low vs high) was in the final best-fit model of factors associated with the occurrence of complications (p < 0.0001)., Conclusions: The rate of total complications for treatment of DS and IS in this series was 9.2%. The total percentage of patients with complications was 7.9%. On univariate analysis, the complication rate was significantly higher in patients with high-grade spondylolisthesis, a diagnosis of DS, and in older patients. Surgical approach and history of previous surgery were not significantly correlated with increased complication rates. On multivariate analysis, only the grade of spondylolisthesis was significantly associated with the occurrence of complications.