Does levelling of T1 tilt intra-operatively affect post-operative shoulder balance in adolescent idiopathic scoliosis patients?

INTRODUCTION: Previous studies have shown that T1 tilt is positively correlated with post-operative shoulder balance (SB). The aim of this study was to explore the role of intra-operative T1 tilt, among other shoulder parameters as a potential parameter to predict post-operative SB in adolescent idiopathic scoliosis (AIS) patients. METHODS: A retrospective review of AIS patients with structural thoracic curves with minimum 2 year follow up was conducted from a single tertiary center. Standing pre-operative, 1st erect, 1 year and 2-year follow-up; and intra-operative final prone radiographs were reviewed along with clinical data. Patients were stratified into 2 cohorts: Group A-Final intra-operative T1 tilt ≤5° and Group B-Final intra-operative T1 tilt >5°. These groups were compared for post-operative SB as a whole and separately for patients with baseline right or left shoulder high and if UIV was T2 or T3/T4. Patients with optimal SB (Radiographic shoulder height (RSH) <2 cm) at 2 years were compared to sub-optimal SB (RSH ≥ 2 cm) with respect to multiple SB variables. RESULTS: 55 patients (mean age 15.1 years-old, 43 F, mean BMI 22, mean thoracic Cobb-49.8°) were included. Based on Lenke curve types, there were 13 patients with type 1A, 10 patients with 1B, 12 patients with 1C, 7 patients with 2A, 4 patients with 2B and 9 patients with type 3C. T1 tilt was significantly correlated with RSH, Clavicle angle difference (CAD), First Rib Angle (FRA), and UIV tilt at first erect, 1-year, and 2-year post-op radiographs (p < 0.05 for all). When comparing groups, A and B, Group A patients showed significantly better restoration of their 2-year SB parameters; RSH (6.8 vs 11.8 mm, p = 0.01), CAD (3.9 vs 9.1 p < 0.001) and T1 tilt (4.7 vs 7.8° p = 0.01). Similar results were found for patients with baseline right shoulder high; RSH (p = 0.04), CAD (p < 0.001) and T1 tilt (p < 0.001) and whether UIV was T2 or T3/T4. Eight patients with sub-optimal SB had worse intra-operative T1 tilt (p = 0.03) compared to 47 patients with optimal SB despite no difference in MT Cobb correction (83.1 vs 79.8%, p = 0.57). CONCLUSION: Post-operative T1 tilt correlates with lateral shoulder parameters at first erect, 1 year, and 2-year radiographs. Therefore, T1 tilt can potentially be used as a surrogate to predict post-operative SB. Leveling intra-operative T1 tilt ≤5° is associated with better 2-year post-operative shoulder balance parameters irrespective of whether the UIV was T2 or T3/T4. Patients with sub-optimal SB at 2 years had worse final intra-operative T1 tilt despite similar percent correction of main thoracic curve for all patients.

Use of navigation for anterior and posterior instrumentation in the surgical management of pediatric pathologic lumbosacral deformity.

We report the use of computerized tomography (CT)-guided navigation for complex spinal deformity correction (anterior and posterior) in an 8-year-old patient with neurofibromatosis complicated by dystrophic pedicles, dural ectasia, and extensive vertebral scalloping. A retrospective review was conducted of the patient's medical records for the past 3 years, including the patient's office visit notes, operative reports, pre- and 2-year postoperative imaging studies. The patient successfully underwent anterior lumbar interbody fusion from L3-S1 using CT-guided navigation to negotiate the challenges posed by dural ectasia and vertebral body scalloping. One week after the anterior procedure, she underwent navigation-guided T10-to-pelvis posterior instrumented fusion. There were no perioperative or postoperative complications at 2 years. In patients with complex deformities of the spine, including dural ectasia, scalloped vertebral bodies, and decreased pedicle integrity, the use of intraoperative CT-guided navigation can benefit surgeons by facilitating the safe placement of interbody spacers and pedicle screws.

Role of Topical Tranexamic Acid on Blood Loss and Transfusion Requirements in Spinal Fusion for Neuromuscular and Syndromic Scoliosis.

STUDY DESIGN: Retrospective case control study. OBJECTIVES: To determine the role of TXA when used as topical soaked sponges (tTXA) on peri-operative blood loss and changes in hemoglobin following posterior spinal fusion (PSF) for neuromuscular and syndromic scoliosis (NMS). METHODS: A single center review of NMS patients who underwent PSF was conducted. The initial set of patients where no tTXA (control) was used were compared to consecutive NMS patients in whom tTXA was used. In the tTXA group, sponges soaked in 1g TXA in 500 mL normal saline were packed in the wound instead of dry sponges. Estimated blood loss (EBL) was calculated intraoperatively using a standard way. Pre-operative, intra-operative and immediate post-operative variables were collected and compared between the 2 groups. RESULTS: 33 patients were included (mean age- 13.5 yrs., BMI- 21, 17 patients in tTXA and 16 patients in control group). Pre-op demographic and radiographic variables were similar between the 2 groups. EBL, EBL per level, EBVL, operative time and number of levels fused were similar in both groups. tTXA group received less intra-operative pRBC transfusion as compared to the control group (150 ± 214 vs 363 ± 186 cc, P = .004). No difference was noted in post-op blood transfusion and drain output for 3 days in both the groups. tTXA group had lesser hospital (5.1 vs 8.9 days) and ICU length of stay (2 vs 4.2 days) and fewer immediate post-operative complications (23.5 vs 52.9%) compared to the control group but not statistically significant (P > .05). CONCLUSION: Administration of tTXA-soaked sponges is an effective and safe method to reduce intraoperative blood transfusion requirements in the correction of spinal deformity in patients with NMS.

Is there an anatomic basis for the different behavior of Lenke types 1AR and 1AL in idiopathic scoliosis? A study on facet joint tropism influence.

INTRODUCTION: AIS type 1 Curves are sub-classified based on the tilt of L4 as 1AR and 1AL. These curves are different w.r.t their curve behavior, progression and level selection. Presently there is no known anatomic etiology for the different behavior. Facet tropism (FT) is defined as the asymmetry between the facet angle of the left and right facet joints. The purpose of this study was to evaluate the correlation between facet tropism in the lumbar segments and occurrence of type 1AR and 1AL curves in AIS patients. METHODS: AIS patients with diagnosis of type 1 AR and 1AL right thoracic AIS curves who underwent posterior instrumented fusion were queried from a single institutions' database. Patients needed to have an MRI of their entire spine to be included. L2-3, L3-4 and L4-5 Facet angles (FA, angle made by the facet line with the mid-sagittal line at respected vertebral level) were calculated. FT was classified as follows: ≤ 5° (minimal), 6- 10° (mild) and ≥ 11° (severe). 1AR and 1AL curves were compared for FA, FT and FT grade at each lumbar segmental levels. RESULTS: One hundred nineteen patients were included (77 females, mean age-13.85 years, mean BMI- 21.63, 73 1AL and 46 1AR). The mean thoracic Cobb was 52.5 ± 9.8°, thoracic kyphosis was 28.12 ± 12° and lumbar lordosis was 53.48 ± 12.6°. L3-4 FA on the right side was more coronally oriented in 1AR curves compared to 1AL curves (37° vs. 31°, p = 0.04). On comparing FT at each level, 1AR curves had a higher FT at L3-4 (1.5° vs. - 2.3°, p = 0.01) and L4-5 levels (5.8° vs. - 0.28°, p < 0.001) compared to 1AL patients. Similarly, 1AR patients had significantly more patients with severe FT at L3-4 (34.8% vs. 13.7%, p = 0.02) and at L4-5 (17.3% vs. 6.8%, p = 0.01) compared to 1ALcurves. CONCLUSION: L3-4 joints are more coronally oriented in 1AR curves compared to 1AL curves. 1AR patients displayed higher FT at L3-4 and L4-5 compared to 1AL patients. 1AR curves also reveal a higher percentage of severe FT at L3-4 and L4-5 levels. This may influence the curve behavior and progression in these two curve types.

Utilization of pre-operative MRI to identify AIS patients at highest risk of intra-operative neuromonitoring alert.

PURPOSE: Utility of pre-operative MRI for patients undergoing scoliosis correction has expanded to include an MRI classification for identifying patients at increased risk of experiencing intra-operative neuromonitoring (IONM) alerts based on the shape of the spinal cord and circumferential presence of CSF at the apex of the thoracic curve. In the present study, the authors explore the utility of this new MRI classification and multiple X-ray radiographic parameters in identifying the AIS sub-population at high risk of IONM alerts. METHODS: AIS patients < 18 years old who underwent posterior spinal fusion between 2018 and 2022 at a single institution. Imaging reviewed to determine main thoracic (MT) and thoraco-lumbar (TL) Cobb angles, major thoracic Apical Vertebral Translation (AVT) and lumbar/thoraco-lumbar AVT (TL AVT), thoracic kyphosis (TK), coronal main thoracic Deformity Angular Ratio (cDAR), sagittal DAR (sDAR), and MRI to determine the spinal cord type (1, 2, or 3). RESULTS: A total of 155 AIS patients who met the inclusion criteria between 2018 and 2022 were included. There was a trend to have an increased incidence of Type 3 spinal cord shape both with increase in the MT Cobb angle and MT AVT. There was also a shift toward more IONM alerts in patients with Type 3 (19.5%) spinal cords, AVT ≥ 5 cm (18.9%), and Cobb angle ≥ 650 (28.2%). CONCLUSION: Higher magnitude of thoracic Cobb angle and AVT are associated with higher likelihood of type 3 spinal cord at the apex in MRI. Patients with Type 3 spinal cord, Cobb angle ≥ 650, AVT > 5 cm, and cDAR > 10 have higher likelihood to have IONM alerts. Patient with a Type 3 spinal cord and a Cobb angle ≥ 650 (50.0%), cDAR > 10 (43.7%), and AVT > 5 cm (35.2%) have the highest risk of having IONM alerts.

Impact of Supine Radiographs to Assess Curve Flexibility in the Treatment of Adolescent Idiopathic Scoliosis.

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: The purpose of the study is to evaluate the role of supine radiographs in determining flexibility of thoracic and thoracolumbar curves. METHODS: Ninety operative AIS patients with 2-year follow-up from a single institution were queried and classified into MT structural and TL structural groups. Equations were derived using linear regression to compute cut-off values for MT and TL curves. Thresholds were externally validated in a separate database of 60 AIS patients, and positive and negative predictive values were determined for each curve. RESULTS: MT supine values were highly predictive of MT side-bending values (TL group: 0.63, P < 0.001; MT group: 0.66, P = 0.006). Similarly, TL supine values were highly predictive of TL side-bending values (TL group: 0.56, P = 0.001 MT group: 0.68, P = 0.001). From our derived equations, MT and TL curves were considered structural on supine films if they were ≥ 30° and 35°, respectively. Contingency table analysis of external validity sample showed that supine films were highly predictive of structurality of MT curve (Sensitivity = 0.91, PPV = 0.95, NPV = 0.81) and TL curve (Sensitivity = 0.77, PPV = 0.81, NPV = 0.94). ROC analysis revealed that the area under curve for MT structurality from supine films was 0.931 (SEM: 0.03, CI: 0.86-0.99, P < 0.001) and TL structurality from supine films was 0.922 (SEM: 0.03, CI- 0.84-0.98, P < 0.001). CONCLUSIONS: A single preoperative supine radiograph is highly predictive of side-bending radiographs to assess curve flexibility in AIS. A cut-off of ≥ 30° for MT and ≥ 35° for TL curves in supine radiographs can determine curve structurality.

Topical tranexemic acid reduces intra-operative blood loss and transfusion requirements in spinal deformity correction in patients with adolescent idiopathic scoliosis.

PURPOSE: To evaluate the effectiveness of the use of topical tranexamic acid (tTXA) in spinal deformity correction in AIS patients METHODS: Sixty consecutive operative AIS patients were reviewed from a single institution and divided into two groups with similar demographics. Standardized peri-operative blood salvage techniques were utilized in all 60 patients. In the latter 30 patients, tTXA soaked sponges (1 g mixed in 500 ml Normal Saline) was utilised for wound packing during the entire surgical procedure compared to dry sponges as used in the former 30 patients. Both the groups were compared for the magnitude of deformity corrected, EBL per level fused, total EBL, blood transfused, drain output and peri-operative events. RESULTS: Sixty AIS patients (mean age 14.4 yrs, 43 females, mean BMI 21.5, mean levels 10.7) were included. Both groups achieved similar change in Coronal Cobb correction. The EBVL (Estimated blood volume loss) % lost in the topical TXA group was 38% less than the control group (11.2 vs. 18.3%, p = 0.006). Similarly, the EBL/level was significantly lower in the topical TXA group (41 ± 30 ml vs. 57 ± 26 ml, p = 0.03). Three of 30 patients in the control group required at least 1 unit of blood transfusion, whereas only 1 patient in the topical TXA group required transfusion (10 vs. 3.3%, p = 0.001). No differences were noted in post-operative drain output, change in hemoglobin levels, and peri-operative complication rates. CONCLUSION: When used as an adjunct to the conventional blood salvage techniques in spinal deformity correction procedures, the use of tTXA resulted in reduced operative blood loss, and blood transfusion requirements.

Safe and effective performance of pediatric spinal deformity surgery in patients unwilling to accept blood transfusion: a clinical study and review of literature.

BACKGROUND: Pediatric deformity surgery traditionally involves major blood loss. Patients refusing blood transfusion add extra clinical and medicolegal challenges; specifically the Jehovah's witnesses population. The objective of this study is to review the safety and effectiveness of blood conservation techniques in patients undergoing pediatric spine deformity surgery who refuse blood transfusion. METHODS: After obtaining institutional review board approval, we retrospectively reviewed 20 consecutive patients who underwent spinal deformity surgery and refused blood transfusion at a single institution between 2014 and 2018. We collected pertinent preoperative, intraoperative and most recent clinical and radiological data with latest follow-up (minimum two-year follow-up). RESULTS: Twenty patients (13 females) with a mean age of 14.1 years were identified. The type of scoliotic deformities were adolescent idiopathic (14), juvenile idiopathic (1), neuromuscular (3) and congenital (2). The major coronal Cobb angle was corrected from 55.4° to 11.2° (80% correction, p <  0.001) at the latest follow-up. A mean of 11.4 levels were fused and 5.6 levels of Pontes osteotomies were performed. One patient underwent L1 hemivertebra resection and three patients had fusion to pelvis. Estimated blood loss, percent estimated blood volume loss, and cell saver returned averaged 307.9 mL, 8.5%, and 80 mL, respectively. Average operative time was 214 min. The average drop in hemoglobin after surgery was 2.9 g/dL. The length of hospital stay averaged 5.1 days. There were no intraoperative complications. Three postoperative complications were identified, none related to their refusal of transfusion. One patient had in-hospital respiratory complication, one patient developed a late infection, and one patient developed asymptomatic radiographic distal junctional kyphosis. CONCLUSIONS: Blood conservation techniques allow for safe and effective spine deformity surgery in pediatric patients refusing blood transfusion without major anesthetic or medical complications, when performed by an experienced multidisciplinary team. LEVEL OF EVIDENCE: Level IV.

Late spinal infections following posterior spinal fusion in pediatric deformities: treatment using single-stage titanium implant exchange.

PURPOSE: Late infection following posterior spinal fusion (PSF) for deformity is a leading cause of revision. The purpose of this study is to evaluate clinical and radiographic outcomes following a single-stage debridement and exchange of spinal implants with titanium in adolescent patients with late-onset infections following PSF METHODS: A retrospective review of prospectively collected data of adolescent patients with spinal deformity, who were surgically treated with PSF was collected. Patients were included for the study if they developed late arising infection (> 1 year after index posterior fusion for the deformity) from 2006-2019. Treatment consisted of irrigation, debridement, implant exchange with titanium screws and rods, and antibiotics. Parameters evaluated include radiographic Cobb angles, operative data, and clinical data, all at minimum 2-year follow-up. RESULTS: 31 patients (29 with AIS and 2 with Scheuermann's kyphosis) developed late spinal infections. Mean age was 11.4 ± 2.3 years, 84% female, mean time from index surgery was 52.5 months. 25 had all stainless steel implants and 6 had cobalt chrome during the index procedure. Positive cultures were obtained in 5 patients (2 Staphylococcus Aureus, 1 Staphylococcus epidermidis, 1 Peptostreptococcus, 1 Pseudomonas aeruginosa) with cultures followed till 7 days post-operatively. At 2-years following the exchange, there was no change in coronal and sagittal alignment. Three (9%) patients developed subsequent infection necessitating implant removal. CONCLUSION: A single-stage procedure consisting of implant removal, irrigation, and debridement, and replacement with all titanium implants is an effective treatment strategy in patients developing late wound infection following PSF with regards to maintenance of curve correction and minimizing recurrent infections.

Mandibular slope: a reproducible and simple measure of horizontal gaze.

STUDY DESIGN: This study is a single-center retrospective radiographic review. OBJECTIVES: The objective of this study is to evaluate a novel measurement parameter, mandibular slope (MS), as a measure of horizontal gaze. INTRODUCTION: Assessment of sagittal spinal alignment is essential in the evaluation of spinal deformity patients. Ability to achieve a horizontal gaze, a parameter of sagittal alignment, is needed for the performance of daily activities. Standard measures of horizontal gaze, including the gold-standard chin-brow to vertical angle (CBVA) and the surrogate measures McGregor's line (McGS) and Chamberlain's line (CS), require high-quality imaging, precise head positioning, and reliance on difficult to view visual landmarks. A novel measurement parameter, MS, utilizing the caudal margin of the mandible on standard lateral spine radiographs is proposed. METHODS: 90 radiographs from spine deformity patients with or without spinal implants from a single center were evaluated. Three spine surgery fellows independently measured CBVA, McGS, CS, and MS at two timepoints at least one week apart to assess accuracy and reliability. MS was measured as the angle created by the inferior edge of the mandibular body and the horizontal. Formulas for calculating CBVA based on the above parameters were derived and compared to the actual CBVA. RESULTS: Mean age was 49.7 years, 76 females and 14 males. CBVA correlated with CS, McGS, and MS, r = 0.85, 0.81, and 0.80, respectively (p < 0.001). Standard error between real CBVA and calculated CBVA using CS (0.4 ± 4.79) and McGS (0.4 ± 3.9) was higher than that calculated using MS (- 0.2 ± 4.3). ICC demonstrated the highest inter-observer reliability with MS (0.999). MS had the highest intra-observer reliabilities 0.975, 0.981, and 0.988 (p < 0.001); CS and McGS also demonstrated high intra-observer reliability. CONCLUSIONS: MS is a promising measure of horizontal gaze that correlates highly with CBVA, has excellent intra- and inter-observer reliability with CBVA, and is easily measured using standard lateral spine radiographs.

The Importance of C2 Slope, a Singular Marker of Cervical Deformity, Correlates With Patient-reported Outcomes.

STUDY DESIGN: Retrospective review of a prospectively collected database. OBJECTIVE: To define a simplified singular measure of cervical deformity (CD), C2 slope (C2S), which correlates with postoperative outcomes. SUMMARY OF BACKGROUND DATA: Sagittal malalignment of the cervical spine, defined by the cervical sagittal vertical axis (cSVA) has been associated with poor outcomes following surgical correction of the deformity. There has been a proliferation of parameters to describe CD. This added complexity can lead to confusion in classifying, treating, and assessing outcomes of CD surgery. METHODS: A prospective database of CD patients was analyzed. Inclusion criteria were cervical kyphosis>10°, cervical scoliosis>10°, cSVA>4 cm, or chin-brow vertical angle >25°. Patients were categorized into two groups and compared based on whether the apex of the deformity was in the cervical (C) or the cervicothoracic (CT) region. Radiographic parameters were correlated to C2S, T1 slope (T1S) and 1-year health-related quality-of-life outcomes as measured by the EuroQol 5 Dimension questionnaire (EQ5D), modified Japanese Orthopedic Association Scale, numeric rating scale for neck pain, and the Neck Disability Index (NDI). RESULTS: One hundred four CD patients (C = 74, CT = 30; mean age 61 yr, 56% women, 42% revisions) were included. CT patients had higher baseline cSVA and T1S (P < 0.05). C2S correlated with T1 slope minus cervical lordosis (TS-CL) (r = 0.98, P < 0.001) and C0-C2 angle, cSVA, CL, T1S (r = 0.37-0.65, P < 0.001). Correlation of cSVA with C0-C2 was weaker (r = 0.48, P < 0.001). At 1-year postoperatively, higher C2S correlated with worse EQ-5D (r = 0.28, P = 0.02); in CT patients, higher C2S correlated with worse NDI, modified Japanese Orthopedic Association Scale, numeric rating scale for neck pain, and EQ5D (all r > 0.5, P≤0.05). Using linear regression, moderate disability by EQ5D corresponded to C2S of 20°(r = 0.08). For CT patients, C2S = 17° corresponded to moderate disability by NDI (r = 0.4), and C2S = 20° by EQ5D (r = 0.25). CONCLUSION: C2S correlated with upper-cervical and subaxial alignment. C2S correlated strongly with TS-CL (R = 0.98, P < 0.001) because C2S is a mathematical approximation of TS-CL. C2S is a useful marker of CD, linking the occipitocervical and cervico-thoracic spine. C2S defines the presence of a mismatch between cervical lordosis and thoracolumbar alignment. Worse 1-year postoperative C2 slope correlated with worse health outcomes. LEVEL OF EVIDENCE: 3.

Anatomic Trajectory for Iliac Screw Placement in Pediatric Scoliosis and Spondylolisthesis: An Alternative to S2-Alar Iliac Portal.

STUDY DESIGN: Single-center retrospective study. OBJECTIVE: To analyze two-year postoperative outcomes following spinopelvic fixation in pediatric patients using the anatomic trajectory (AT) portal for iliac screws. SUMMARY: Iliac fixation is crucial in situations requiring fusion to sacrum. Challenges include complex anatomy, pelvic deformation, severe deformity, and previous surgery. The PSIS portal requires significant dissection, rod connectors, and complex bends. The SAI portal requires navigating the screw across the SI joint to the ilium. The anatomic trajectory (AT), first reported in 2009, is between the PSIS and SAI portal, without prominence, connectors, or complex bends. METHODS: Fifty-four patients aged ≤18 years requiring instrumentation to the Ilium with minimum follow-up of two years (mean 44 months) were clinically and radiographically evaluated. Changes in coronal curve magnitude and pelvic obliquity were assessed using paired t test for patients with cerebral palsy. Spondylolisthesis reduction was assessed in patients with moderate- to high-grade spondylolisthesis (Meyerding grade 3 and 4). RESULTS: A total of 108 iliac screws were inserted using AT portal in 54 patients. Twenty-eight neuromuscular and syndromic patients had an initial mean coronal curve of 85° corrected to 23° at two years (p < .001) and a pelvic obliquity of 22° corrected to 4° (p < .001). Twenty patients with moderate- to high-grade spondylolisthesis treated with reduction and interbody fixation improved significantly with respect to their slip angles (7° ± 14.7° to -7.9° ± 6.1°, p = .003). In the neuromuscular group, two surgical site infections occurred, two had implant fractures, and 12 had asymptomatic iliac screw loosening, none requiring revision. In the spondylolisthesis group, there were no neurologic complications and one had prominent screw requiring removal. Of 108 iliac screws, 2 rod connectors were employed. CONCLUSION: Iliac screw insertion using the AT portal is a safe and effective method of pelvic fixation in pediatric patients with satisfactory radiographic correction and minimal complications. LEVEL OF EVIDENCE: Level 4.

Measurement of Spinopelvic Angles on Prone Intraoperative Long-Cassette Lateral Radiographs Predicts Postoperative Standing Global Alignment in Adult Spinal Deformity Surgery.

STUDY DESIGN: Retrospective review from a single institution. OBJECTIVES: To evaluate intraoperative T1-pelvic angle (TPA), T4PA, and T9PA as predictors of postoperative global alignment after adult spinal deformity (ASD) surgery. SUMMARY OF BACKGROUND DATA: Malalignment following adult spinal surgery is associated with disability and correlates with health-related quality of life. Preoperative planning and intraoperative verification are crucial for optimal postoperative outcomes. Currently, only pelvic incidence minus lumbar lordosis (PI-LL) mismatch has been used to assess intraoperative correction. METHODS: Patients undergoing ≥4-level spinal fusion with full-length pre-, intra-, and first postoperative calibrated radiographs were included from a single institution. Alignment measurements were obtained for sagittal vertical axis (SVA), PI-LL, TPA, T4PA, and T9PA. The whole cohort was divided into upper thoracic (UT: UIV > T7) and lower thoracic fusions (LT: UIV < T7). Change was assessed between phases, and a subanalysis was included for UT and LT groups to compare alignment changes for differing extent of proximal fusion in the sagittal plane. RESULTS: Eighty patients (mean 63.4 years, 70% female, mean levels fused 11.9) underwent significant ASD correction (ΔPI-LL = 22.1°; ΔTPA = 13.8°). For all, intraoperative TPA, T4PA, and T9PA correlated with postoperative SVA (range, r = 0.41-0.59), whereas intraoperative PI-LL correlated less (r = 0.38). For UT (n = 49), all spinopelvic angles and LL were similar intraoperative to postoperatively (p > .09). For LT (n = 31), intraoperative and postoperative T9PA and LL were similar (p > .10) but TPA and T4PA differed (p < .02). For UT, all intraoperative and postoperative spinopelvic angles strongly correlated (r = 0.8-0.9). For LT, intraoperative to postoperative T9PA strongly correlated (r = 0.83) and TPA, T4PA, and LL correlated moderately (r = 0.65-0.70). LT trended toward more reciprocal kyphosis postoperatively (8.1° vs. 2.6°; p = .059). CONCLUSIONS: Intraoperative measurements of TPA, T4PA, and T9PA correlated better with postoperative global alignment than PI-LL, demonstrating their utility in confirming alignment goals. When comparing intraoperative to postoperative films, only T9PA was similar in LT whereas all spinopelvic angles were similar in UT. Reciprocal kyphosis in unfused segments of LT fusions may account for difference in TPA and T4PA from intraoperative to postoperative films. LEVEL OF EVIDENCE: Level III.

The Impact of Different Intraoperative Fluid Administration Strategies on Postoperative Extubation Following Multilevel Thoracic and Lumbar Spine Surgery: A Propensity Score Matched Analysis.

BACKGROUND: Patients undergoing multilevel spine surgery are at risk for delayed extubation. OBJECTIVE: To evaluate the impact of type and volume of intraoperative fluids administered during multilevel thoracic and/or lumbar spine surgery on postoperative extubation status. METHODS: Retrospective evaluation of medical records of patients ≥ 18 yr undergoing ≥ 4 levels of thoracic and/or lumbar spine fusions was performed. Patients were organized according to postoperative extubation status: immediate (IMEX; in OR/PACU) or delayed (DEX; outside OR/PACU). Propensity score matched (PSM) analysis was performed to compare IMEX and DEX groups. Volume, proportion, and ratios of intraoperative fluids administered were evaluated for the associated impact on extubation status. RESULTS: A total of 246 patients (198 IMEX, 48 DEX) were included. PSM analysis demonstrated that increased administration of non-cell saver blood products (NCSB) and increased ratio of crystalloid: colloids infused were independently associated with delayed extubation. With increasing EBL, IMEX had a proportionate reduction in crystalloid infusion (R = -0.5, P < .001), while the proportion of crystalloids infused remained relatively unchanged for DEX (R = -0.27; P = .06). Twenty-six percent of patients receiving crystalloid: colloid ratio > 3:1 had DEX compared to none of those receiving crystalloid: colloid ratio ≤ 3:1 (P = .009). DEX had greater cardiac and pulmonary complications, surgical site infections and prolonged intensive care unit and hospital stay (P < .05). CONCLUSION: PSM analysis of patients undergoing multilevel thoracic and/or lumbar spine fusion demonstrated that increased administration of crystalloid to colloid ratio is independently associated with delayed extubation. With increasing EBL, a proportionate reduction of crystalloids facilitates early extubation.

Evaluating cervical deformity corrective surgery outcomes at 1-year using current patient-derived and functional measures: are they adequate?

BACKGROUND: Current health-related quality of life (HRQL) metrics used to assess patient outcomes following surgical correction of cervical deformity (CD) are not deformity-specific and thus cannot capture all aspects of a patient's deformity and outcomes. The purpose of this study is to evaluate the sensitivity of different HRQL outcome measures in assessing CD patients' outcomes 1-year post-operatively. METHODS: Retrospective review of prospective multi-center database. Inclusion criteria: CD patients ≥18 yrs with pre- and 1-year post-operative radiographs and HRQLs [modified Japanese Orthopaedic Association (mJOA), EuroQol five-dimensions (EQ-5D), neck disability index (NDI)]. Associations between changes in EQ5D and NDI with improvement at 1-year in mJOA scores were assessed by whether or not the patient met the minimum clinically important difference (MCID) as well as whether or not they improved by one or more categories (i.e., change from moderate to mild). Odds ratios reported with 95% confidence intervals. RESULTS: Sixty-three CD patients were included (mean 62 y, 55.6% F). Average baseline NDI scores were 46.75, mJOA was 13.68, and EQ-5D 0.74. Overall baseline myelopathy breakdown: none-9.5%, mild-30.2%, moderate-42.9%, high-17.5%. At 1-year, 46% of patients improved in mJOA, 71.4% NDI, and 65.1% EQ-5D. 19% of patients met mJOA MCID, 44.4% NDI MCID, 19% EQ-5D MCID. One-point improvement in NDI increased the odds of mJOA improvement and reaching mJOA MCID (improvement: OR, 1.06, CI: 1.01-1.10, P=0.01; MCID: OR, 1.06, CI: 1.02-1.11, P=0.006). Improvement in EQ-5D by 0.1 increased the odds of improving in mJOA and reaching mJOA MCID at 1-year (improvement: OR, 3.85, CI: 1.51-9.76, P=0.005; MCID: OR, 3.88, CI: 1.52-9.88, P=0.005). While correlations exist between outcome measures, when modeling these outcomes while controlling for confounders including cSVA change, surgical invasiveness, age and CCI, these HRQLs were not strongly correlated. CONCLUSIONS: Improvements in functional outcomes, as defined by mJOA score, were correlated with changes in neck based disability and general health state, defined by NDI and EQ-5D respectively. In an adjusted model, however, these direct relationships were not maintained. A CD-specific HRQL might be more useful for surgeons in assessing patient outcomes using a single metric.

Full-Body Analysis of Adult Spinal Deformity Patients' Age-Adjusted Alignment at 1 Year.

BACKGROUND: Previous studies have built a foundation for understanding compensation in patients with adult spinal deformity (ASD) by using full-body stereographic assessments. These mechanisms, in relation to age-adjusted alignment targets, have yet to be studied fully. The aim of this study was to assess lower-limb compensatory mechanisms of patients failing to meet age-adjusted alignment goals. METHODS: Patients with ASD ≥40 years with full body baseline and follow-up radiographs were included. Patients were stratified by age (40-65 years, >65 years) and spinopelvic correction. Lower-limb compensation parameters (pelvic shift, hip extension, knee flexion [KA], ankle flexion [AA], and global sagittal angle [GSA]) for patients who matched and failed to match age-adjusted alignment targets were compared with analysis of variance and t-test analysis. RESULTS: In total, 108 patients were included. At 1 year, AA increased with age in the "match" pelvic tilt (PT) and spinopelvic mismatch (PI-LL) cohorts (PT: AA, 5.6-7.8, P = 0.041; PI-LL: 4.9-8.8, P = 0.026). KA, AA, and GSA increased with age in the "match" sagittal vertical axis (SVA) cohort (KA: 3.8-13.1, P = 0.002; AA: 5.8-10.2, P = 0.008; GSA: 3.9-7.8, P < 0.001), as did KA and GSA in the "match" T1 pelvic angle group (KA: 1.8-8.7, P = 0.020; GSA: 2.6-5.7, P = 0.004). CONCLUSIONS: Greater compensation captured by KA and GSA was associated with age progression in the "match" SVA and T1 pelvic angle cohorts. In addition, older SVA, PT, and PI-LL "match" cohorts used increased AA, suggesting that ideal postoperative alignment of aged individuals with ASD involves increased compensation.

Primary Drivers of Adult Cervical Deformity: Prevalence, Variations in Presentation, and Effect of Surgical Treatment Strategies on Early Postoperative Alignment.

BACKGROUND: Primary drivers (PDs) of adult cervical deformity (ACD) have not been described in relation to pre- and early postoperative alignment or degree of correction. OBJECTIVE: To define the PDs of ACD to understand the impact of driver region on global postoperative compensatory mechanisms. METHODS: Primary cervical deformity driver/vertebral apex level were determined: CS = cervical; CTJ = cervicothoracic junction; TH = thoracic; SP = spinopelvic. Patients were evaluated if surgery included PD apex, based on the lowest instrumented vertebra (LIV): CS: LIV ≤ C7, CTJ: LIV ≤ T3, TH: LIV ≤ T12. Cervical and thoracolumbar alignment was measured preoperatively and 3 mo (3M) postoperatively. PD groups were compared with analysis of variance/Pearson χ2, paired t-tests. RESULTS: Eighty-four ACD patients met inclusion criteria. Thoracic drivers (n = 26) showed greatest preoperative cervical and global malalignment against other PD: higher thoracic kyphosis, pelvic incidence-lumbar lordosis (PI-LL), T1 slope C2-T3 sagittal vertical axis (SVA), and C0-2 angle (P < .05). Differences in baseline-3M alignment changes were observed between surgical PD groups, in PI-LL, LL, T1 slope minus cervical lordosis (TS-CL), cervical SVA, C2-T3 SVA (P < .05). Main changes were between TH and CS driver groups: TH patients had greater PI-LL (4.47° vs -0.87°, P = .049), TS-CL (-19.12° vs -4.30, P = .050), C2-C7 SVA (-18.12 vs -4.30 mm, P = .007), and C2-T3 SVA (-24.76 vs 8.50 mm, P = .002) baseline-3M correction. CTJ drivers trended toward greater LL correction compared to CS drivers (-6.00° vs 0.88°, P = .050). Patients operated at CS driver level had a difference in the prevalence of 3M TS-CL modifier grades (0 = 35.7%, 1 = 0.0%, 2 = 13.3%, P = .030). There was a significant difference in 3M chin-brow vertical angle modifier grade distribution in TH drivers (0 = 0.0%, 1 = 35.9%, 2 = 14.3%, P = .049). CONCLUSION: Characterizing ACD patients by PD type reveals differences in pre- and postoperative alignment. Evaluating surgical alignment outcomes based on PD inclusion is important in understanding alignment goals for ACD correction.

Characterizing Adult Cervical Deformity and Disability Based on Existing Cervical and Adult Deformity Classification Schemes at Presentation and Following Correction.

BACKGROUND: Adult cervical deformity (ACD) classifications have not been implemented in a prospective ACD population and in conjunction with adult spinal deformity (ASD) classifications. OBJECTIVE: To characterize cervical deformity type and malalignment with 2 classifications (Ames-ACD and Schwab-ASD). METHODS: Retrospective review of a prospective multicenter ACD database. Inclusion: patients ≥18 yr with pre- and postoperative radiographs. Patients were classified with Ames-ACD and Schwab-ASD schemes. Ames-ACD descriptors (C = cervical, CT = cervicothoracic, T = thoracic, S = coronal, CVJ = craniovertebral) and alignment modifiers (cervical sagittal vertical axis [cSVA], T1 slope minus cervical lordosis [TS-CL], modified Japanese Ortphopaedic Association [mJOA] score, horizontal gaze) were assigned. Schwab-ASD curve type stratification and modifier grades were also designated. Deformity and alignment group distributions were compared with Pearson χ2/ANOVA. RESULTS: Ames-ACD descriptors in 84 patients: C = 49 (58.3%), CT = 20 (23.8%), T = 9 (10.7%), S = 6 (7.1%). cSVA modifier grades differed in C, CT, and T deformities (P < .019). In C, TS-CL grade prevalence differed (P = .031). Among Ames-ACD modifiers, high (1+2) cSVA grades differed across deformities (C = 47.7%, CT = 89.5%, T = 77.8%, S = 50.0%, P = .013). Schwab-ASD curve type and presence (n = 74, T = 2, L = 6, D = 2) differed significantly in S deformities (P < .001). Higher Schwab-ASD pelvic incidence minus lumbar lordosis grades were less likely in Ames-ACD CT deformities (P = .027). Higher pelvic tilt grades were greater in high (1+2) cSVA (71.4% vs 36.0%, P = .015) and high (2+3) mJOA (24.0% vs 38.1%, P = .021) scores. Postoperatively, C and CT deformities had a trend toward lower cSVA grades, but only C deformities differed in TS-CL grade prevalence (0 = 31.3%, 1 = 12.2%, 2 = 56.1%, P = .007). CONCLUSION: Cervical deformities displayed higher TS-CL grades and different cSVA grade distributions. Preoperative associations with global alignment modifiers and Ames-ACD descriptors were observed, though only cervical modifiers showed postoperative differences.

Cervical Alignment Changes in Patients Developing Proximal Junctional Kyphosis Following Surgical Correction of Adult Spinal Deformity.

BACKGROUND: Proximal junctional kyphosis (PJK) following adult spinal deformity (ASD) surgery is a well-documented complication, but associations between radiographic PJK and cervical malalignment onset remain unexplored. OBJECTIVE: To study cervical malalignment in ASD surgical patients that develop PJK. METHODS: Retrospective review of prospective multicenter database. Inclusion: primary ASD patients (≥5 levels fused, upper instrumented vertebra [UIV] at T2 or above, and 1-yr minimum follow-up) without baseline cervical deformity (CD), defined as ≥2 of the following criteria: T1 slope minus cervical lordosis < 20°, cervical sagittal vertical axis < 4 cm, C2-C7 cervical lordosis < 10°. PJK presence (<10° change in UIV and UIV + 2 kyphosis) and angle were identified 1 yr postoperative. Propensity score matching between PJK and nonPJK groups controlled for baseline alignment. Preoperative and 1-yr postoperative cervical alignment were compared between PJK and nonPJK patients. RESULTS: One hundred sixty-three patients without baseline CD (54.9 yr, 83.9% female) were included. PJK developed in 60 (36.8%) patients, with 27 (45%) having UIV above T7. PJK patients had significantly greater baseline T1 slope in unmatched and propensity score matching comparisons (P < .05). At 1 yr postoperative, PJK patients had significantly higher T1 slope (P < .001), C2-T3 Cobb (P = .04), and C2-T3 sagittal vertical axis (P = .02). New-onset CD rate in PJK patients was 15%, and 16.5% in nonPJK patients (P > .05). Increased PJK magnitude was associated with increasing T1 slope and C2-T3 SVA (P < .05). CONCLUSION: Patients who develop PJK following surgical correction of ASD have a 15% incidence of development of new-onset CD. Patients developing PJK following surgical correction of ASD tend to have an increased preoperative T1 slope. Increased progression of C2-T3 Cobb angle and C2-T3 SVA are associated with development of PJK following surgical correction of thoracolumbar deformity.