scholarly journals Direct Lateral Corpectomy and Reconstruction Using an Expandable Cage Improves Local Kyphosis but Not Global Sagittal Alignment

2021 ◽  
Vol 10 (17) ◽  
pp. 4012
Author(s):  
Hidetomi Terai ◽  
Shinji Takahashi ◽  
Hiroyuki Yasuda ◽  
Sadahiko Konishi ◽  
Takafumi Maeno ◽  
...  
Keyword(s):  
Vertebral Fracture ◽  
Vertical Axis ◽  
Global Alignment ◽  
Sagittal Vertical Axis ◽  
Expandable Cage ◽  
Postoperative Changes ◽  
Global Sagittal Alignment ◽  
Adjacent Vertebral Fracture ◽  
Vertebral Replacement ◽  
The Impact

Recently, an expandable cage equipped with rectangular footplates has been used for anterior vertebral replacement in osteoporotic vertebral fracture (OVF). However, the postoperative changes in global alignment have not been elucidated. The purpose of this study was to evaluate local and global spinal alignment after anterior and posterior spinal fixation (APSF) using an expandable cage in elderly OVF patients. This retrospective multicenter review assessed 54 consecutive patients who underwent APSF for OVF. Clinical outcomes were compared between postoperative sagittal vertical axis (SVA) > 95 mm and ≤95 mm groups to investigate the impact of malalignment. SVA improved by only 18.7 mm (from 111.8 mm to 93.1 mm). VAS score of back pain at final follow-up was significantly higher in patients with SVA > 95 mm than SVA ≤ 95 mm (42.4 vs. 22.6, p = 0.007). Adjacent vertebral fracture after surgery was significantly more frequent in the SVA > 95 mm (37% vs. 11%, p = 0.038). Multiple logistic regression showed significantly increased OR for developing adjacent vertebral fracture (OR = 4.76, 95% CI 1.10–20.58). APSF using the newly developed cage improves local kyphotic angle but not SVA. The main cause for the spinal malalignment after surgery was postoperative development of adjacent vertebral fractures.

scholarly journals Lumbar Level Significantly Influences Postoperative Global Sagittal Balance Following Pedicle Subtraction Osteotomy

2021 ◽  
pp. 219256822110325
Author(s):  
Athan G. Zavras ◽  
T. Barrett Sullivan ◽  
Navya Dandu ◽  
Howard S. An ◽  
Christopher J. DeWald ◽  
...  
Keyword(s):  
Sagittal Balance ◽  
Sagittal Alignment ◽  
Adult Spinal Deformity ◽  
Vertical Axis ◽  
Pedicle Subtraction Osteotomy ◽  
Current Evidence ◽  
Sacral Slope ◽  
Sagittal Vertical Axis ◽  
Lumbar Level ◽  
Global Sagittal Alignment

Study Design: Retrospective cohort study. Objectives: The current evidence regarding how level of lumbar pedicle subtraction osteotomy (PSO) influences correction of sagittal alignment is limited. This study sought to investigate the relationship of lumbar level and segmental angular change (SAC) of PSO with the magnitude of global sagittal alignment correction. Methods: This study retrospectively evaluated 53 consecutive patients with adult spinal deformity who underwent lumbar PSO at a single institution. Radiographs were evaluated to quantify the effect of PSO on lumbar lordosis (LL), thoracic kyphosis (TK), sacral slope (SS), pelvic tilt (PT), pelvic incidence (PI), T1-spinopelvic inclination (T1SPI), T1-pelvic alignment (TPA), and sagittal vertical axis (SVA). Results: Significant correlations were found between PSO SAC and the postoperative increase in LL ( r = 0.316, P = .021) and PT ( r = 0.352, P = .010), and a decrease in TPA ( r = −0.324, P = .018). PSO level significantly correlated with change in T1SPI ( r = −0.305, P = .026) and SVA ( r = −0.406, P = .002), with more caudal PSO corresponding to a greater correction in sagittal balance. On multivariate analysis, more caudal PSO level independently predicted a greater reduction in T1SPI (β = −3.138, P = .009) and SVA (β = −29.030, P = .001), while larger PSO SAC (β = −0.375, P = .045) and a greater number of fusion levels (β = −1.427, P = .036) predicted a greater reduction in TPA. Conclusion: This study identified a gain of approximately 3 degrees and 3 cm of correction for each level of PSO more caudal to L1. Additionally, a larger PSO SAC predicted greater improvement in TPA. While further investigation of these relationships is warranted, these findings may help guide preoperative PSO level selection.

scholarly journals Sagittal spinal-pelvic alignment in patients with Crowe type IV developmental dysplasia of the hip

2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Peng Ren ◽  
Xiangpeng Kong ◽  
Wei Chai ◽  
Yan Wang
Keyword(s):  
Low Back Pain ◽  
Back Pain ◽  
Vertical Axis ◽  
Developmental Dysplasia ◽  
Sacral Slope ◽  
Low Back ◽  
Sagittal Vertical Axis ◽  
Type Iv ◽  
The Impact ◽  
Dysplasia Of The Hip

Abstract Background The impact of high dislocated dysplastic hips on spinal-pelvic alignment has not been well described. This study aims to evaluate compensatory spinal radiographic changes and presence of back pain in patients with Crowe type IV developmental dysplasia of the hip (DDH). Methods An observational study was conducted from July 2016 to December 2017, and 49 consecutive patients with Crowe IV DDH were enrolled. Forty-nine sex- and age-matched asymptomatic healthy adults were recruited as the controls. The sacral slope (SS), lumbar lordosis (LL), spino-sacral angle (SSA), C7 tilt (C7T), and sagittal vertical axis (SVA [C7]) were measured on lateral whole spine radiographs. The presence of low back pain and visual analogue scale (VAS) scores were recorded. Results The patients with Crowe IV DDH showed significantly greater SS (47.5 ± 7.5° vs. 40.4 ± 6.7°, p < 0.05), LL (− 63.7 ± 9.2° vs. − 53.3 ± 11.5°, P < 0.05), SSA (141.8° ± 7.2° vs. 130.6 ± 7.9°, p < 0.05), C7T (93.9 ± 3.6° vs. 91.1 ± 3.7°, P < 0.05), and lower SVA(C7) (− 16 mm[− 95–45] vs. 6.4 mm[− 52–47], p < 0.05) compared to the controls. The patients with bilateral Crowe IV DDH also exhibited larger SS, LL, SSA, and C7T and a smaller SVA (C7) than those with unilateral Crowe IV DDH. Sixty-three percent of the patients with Crowe IV DDH reported low back pain. Conclusion The patients with Crowe IV DDH exhibited abnormal spinal-pelvic alignment characterized by anterior pelvic tilt, lumbar hyperlordosis, and a backward-leaning trunk. Bilateral Crowe IV DDH had a greater impact on spinal-pelvic alignment than unilateral Crowe IV DDH.

scholarly journals Beyond Pelvic Incidence–Lumbar Lordosis Mismatch: The Importance of Assessing the Entire Spine to Achieve Global Sagittal Alignment

2017 ◽  
Vol 7 (6) ◽  
pp. 536-542 ◽  
Author(s):  
Robert K. Merrill ◽  
Jun S. Kim ◽  
Dante M. Leven ◽  
Joung Heon Kim ◽  
Samuel K. Cho
Keyword(s):  
Lumbar Lordosis ◽  
Pelvic Incidence ◽  
Adult Spinal Deformity ◽  
Case Series ◽  
Vertical Axis ◽  
Retrospective Case ◽  
Sagittal Vertical Axis ◽  
Global Sagittal Alignment ◽  
Sagittal Parameters ◽  
Combined Parameters

Study Design: Retrospective case series. Objective: To investigate which sagittal parameters contribute to a normal sagittal vertical axis (SVA) when there is a pelvic incidence-lumbar lordosis (PI-LL) mismatch >10° following adult spinal deformity (ASD) correction. Methods: We performed a retrospective review of ASD patients with >5 levels fused. Sagittal measurements between cohorts of postoperative PI-LL >10° and PI-LL<10° were compared. We correlated SVA to pelvic tilt (PT), thoracic kyphosis (TK), PI-LL, cervical lordosis (CL), and correlated the pre- to postoperative change in SVA to change in PT, change in TK, change in PI-LL, and change in CL. We also correlated SVA and the change in SVA to combined parameters of ((PI-LL) − PT + TK). Results: We analyzed 52 patients with a mean age of 59 ± 16 years. In patients with a postoperative SVA <5cm, a smaller TK was seen when PI-LL >10° than when PI-LL<10° (15.45° vs 33.04°, P = .0004). Additionally, PT was larger when PI-LL >10° than when PI-LL <10° (25.73° vs 19.07°, P = .006). SVA correlated better with ((PI-LL) − PT + TK) ( R2 = 0.51) than with PI-LL alone ( R2 = 0.33). Lastly, there was no significant correlation between change in pre- to postoperative SVA with change in TK for all cases ( P = .73), but in cases where change in PI-LL was <10°, there was a significant correlation between change in TK and change in SVA ( P = .009). Conclusion: Our results demonstrate that PT and TK, and not just PI-LL, play an important role in maintaining sagittal balance when there is a PI-LL mismatch >10°.

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

Neurosurgery ◽  
2017 ◽  
Vol 82 (2) ◽  
pp. 192-201 ◽  
Author(s):  
Peter G Passias ◽  
Cyrus M Jalai ◽  
Justin S Smith ◽  
Virginie Lafage ◽  
Bassel G Diebo ◽  
...  
Keyword(s):  
Pelvic Tilt ◽  
Pelvic Incidence ◽  
Adult Spinal Deformity ◽  
Vertical Axis ◽  
Global Alignment ◽  
Sagittal Vertical Axis ◽  
Adult Deformity ◽  
Cervical Deformity ◽  
Curve Type ◽  
Horizontal Gaze

Abstract 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 &lt; .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 &lt; .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.

scholarly journals Cervical, Thoracic, and Spinopelvic Compensation After Proximal Junctional Kyphosis (PJK): Does Location of PJK Matter?

2019 ◽  
Vol 10 (1) ◽  
pp. 6-12 ◽  
Author(s):  
Han Jo Kim ◽  
Philip J. York ◽  
Jonathan C. Elysee ◽  
Christopher Shaffrey ◽  
Douglas C. Burton ◽  
...  
Keyword(s):  
Correlation Analysis ◽  
Case Series ◽  
Vertical Axis ◽  
Global Alignment ◽  
Proximal Junctional Kyphosis ◽  
Retrospective Case ◽  
Sagittal Vertical Axis ◽  
Cervical Alignment ◽  
Compensation Mechanisms ◽  
Junctional Kyphosis

Study Design: Retrospective case series. Objective: Compensatory changes above a proximal junctional kyphosis (PJK) have not been defined. Understanding these mechanisms may help determine optimal level selection when performing revision for PJK. This study investigates how varying PJK location changes proximal spinal alignment. Methods: Patients were grouped by upper instrumented vertebrae (UIV): lower thoracic (LT; T8-L1) or upper thoracic (UT; T1-7). Alignment parameters were compared. Correlation analysis was performed between PJK magnitude and global/cervical alignment. Results: A total of 369 patients were included; mean age of 63 years, body mass index 28, and 81% female, LT (n = 193) versus UT (n = 176). The rate of radiographic PJK was 49%, higher in the LT group (55% vs 42%, P = .01). The UT group displayed significant differences in all cervical radiographic parameters ( P < .05) between PJK versus non-PJK patients, while the LT group displayed significant differences in T1S and C2-T3 sagittal vertical axis (SVA) (CTS). In comparing UT versus LT patients, UT had more posterior global alignment (smaller TPA [T1 pelvic angle], SVA, and larger PT [pelvic tilt]) and larger anterior cervical alignment (greater cSVA [cervical SVA], T1S-CL [T1 slope–cervical lordosis] mismatch, CTS) compared to LT. Correlation analysis of PJK magnitude and location demonstrated a correlation with increases in CL, T1S, and CTS in the UT group. In the LT group, PT increased with PJK angle ( r = 0.17) and no significant correlations were noted to SVA, cSVA, or T1S-CL. Conclusions: PJK location influences compensation mechanisms of the cervical and thoracic spine. LT PJK results in increased PT and CL with decreased CTS. UT PJK increases CL to counter increases in T1S with continued T1S-CL mismatch and elevated cSVA.

scholarly journals Can posterior stand-alone expandable cages safely restore lumbar lordosis? A minimum 5-year follow-up study

2020 ◽  
Author(s):  
Seung-Kook Kim ◽  
Ogeil Mubarak Elbashier ◽  
Su-chan Lee ◽  
Woo-jin Choi
Keyword(s):  
Sagittal Balance ◽  
Lumbar Lordosis ◽  
Vertical Axis ◽  
Control Group ◽  
Sacral Slope ◽  
Sagittal Vertical Axis ◽  
Expandable Cage ◽  
Cage Group

Abstract Background: Lumbar lordosis (LL) can be restored, and screw-related complications may be avoided with the stand-alone expandable cage method. However, the long-term spinopelvic changes and safety remain unknown. We aimed to elucidate the long-term radiologic outcomes and safety of this technique. Methods: Data from patients who underwent multi-level stand-alone expandable cage fusion and 80 patients who underwent screw-assisted fusion between February 2007 and December 2012, with at least 5 years of follow-up, were retrospectively analyzed. Segmental angle and translation, short and whole LL, pelvic incidence, pelvic tilt, sacral slope (SS), sagittal vertical axis, thoracic kyphosis, and presence of subsidence, pseudoarthrosis, retropulsion, cage breakage, proximal junctional kyphosis (PJK), and screw malposition were assessed. The relationship between local, lumbar, and spinopelvic effects was investigated. The implant failure rate was considered a measure of procedure effectiveness and safety. Results: In total, 69 cases were included in the stand-alone expandable cage group and 150 cases in the control group. The stand-alone group showed shorter operative time (58.48±11.10 versus 81.43±13.75, P=.00028), lower rate of PJK (10.1% versus 22.5%, P=.03), and restoration of local angle (4.66±3.76 versus 2.03±1.16, P=.000079) than the control group. However, sagittal balance (0.01±2.57 versus 0.50 ±2.10, P=.07) was not restored, and weakness showed higher rate of subsidence (16.31% versus 4.85 %, P=.0018), pseudoarthrosis (9.92% versus 2.42%, P=.02), cage, and retropulsion (3.55% versus 0, P=.01) than the control group.Conclusions: Stand-alone expandable cage fusion can restore local lordosis; however, global sagittal balance was not restored. Furthermore, implant safety has not yet been proven.

scholarly journals Are the sagittal cervical radiographic modifiers of the Ames-ISSG classification specific to adult cervical deformity?

2018 ◽  
Vol 29 (5) ◽  
pp. 483-490 ◽  
Author(s):  
Ziad Bakouny ◽  
Nour Khalil ◽  
Joeffroy Otayek ◽  
Aren Joe Bizdikian ◽  
Fares Yared ◽  
...  
Keyword(s):  
Japanese Orthopaedic Association ◽  
Vertical Axis ◽  
Research Society ◽  
Cross Sectional Study ◽  
Global Alignment ◽  
Sagittal Vertical Axis ◽  
Cross Sectional ◽  
Scoliosis Research Society ◽  
Cervical Deformity ◽  
Asymptomatic Subjects

OBJECTIVEThe Ames–International Spine Study Group (ISSG) classification has recently been proposed as a tool for adult cervical deformity evaluation. This classification includes three radiographic cervical sagittal modifiers that have not been evaluated in asymptomatic adults. The aim of this study was to determine whether the sagittal radiographic modifiers described in the Ames-ISSG cervical classification are encountered in asymptomatic adults without alteration of health-related quality of life (HRQOL).METHODSThe authors conducted a cross-sectional study of subjects with an age ≥ 18 years and no cervical or back-related complaints or history of orthopedic surgery. All subjects underwent full-body biplanar radiographs with the measurement of cervical, segmental, and global alignment and completed the SF-36 HRQOL questionnaire. Subjects were classified according to the sagittal radiographic modifiers (chin-brow vertical angle [CBVA], mismatch between T1 slope and cervical lordosis [TS-CL], and C2–7 sagittal vertical axis [cSVA]) of the Ames–ISSG classification for cervical deformity, which also includes a qualitative descriptor of cervical deformity, the modified Japanese Orthopaedic Association (mJOA) myelopathy score, and the Scoliosis Research Society (SRS)–Schwab classification for spinal deformity assessment. Characteristics of the subjects classified by the different modifier grades were compared.RESULTSOne hundred forty-one asymptomatic subjects (ages 18–59 years, 71 females) were enrolled in the study. Twenty-seven (19.1%) and 61 (43.3%) subjects were classified as grade 1 in terms of the TS-CL and CBVA modifiers, respectively. Ninety-eight (69.5%) and 4 (2.8%) were grade 2 for these same respective modifiers. One hundred thirty-six (96.5%) subjects had at least one modifier at grade 1 or 2. There was a significant relationship between patient age and grades of TS-CL (p < 0.001, Cramer’s V [CV] = 0.32) and CBVA (p = 0.04, CV = 0.22) modifiers. The HRQOL, global alignment, and segmental alignment parameters were similar among the subjects with different modifier grades (p > 0.05).CONCLUSIONSThe CBVA and TS-CL radiographic modifiers of the Ames-ISSG classification do not seem to be specific to subjects with cervical deformities and can occur in asymptomatic subjects without alteration in HRQOL.

scholarly journals The impact of spinopelvic morphology on the short-term outcome of pedicle subtraction osteotomy in 104 patients

2017 ◽  
Vol 27 (1) ◽  
pp. 74-80 ◽  
Author(s):  
Karin Eskilsson ◽  
Deep Sharma ◽  
Christer Johansson ◽  
Rune Hedlund
Keyword(s):  
Clinical Outcome ◽  
Sagittal Plane ◽  
Vertical Axis ◽  
Pedicle Subtraction Osteotomy ◽  
Sacral Slope ◽  
Sagittal Imbalance ◽  
Sagittal Vertical Axis ◽  
Term Outcome ◽  
Pelvic Morphology ◽  
The Impact

OBJECTIVEPedicle subtraction osteotomy (PSO) is commonly performed for correction of spinal sagittal plane deformities. The PSO results in complex, multiple changes of the spinopelvic alignment. The influence of the variability of individual pelvic morphology has not been fully analyzed in previous outcome studies of sagittal imbalance. The aim of this study was to define radiological variables affecting the outcome after PSO in adult spinal deformities, with special emphasis on the variability of pelvic morphology.METHODSClinical and radiographic outcomes were analyzed in a retrospective analysis of 104 patients who underwent a PSO at a single center. The radiographic variables studied were sagittal vertical axis (SVA), T1SPI (T-1 spinopelvic inclination), lumbar lordosis (LL), thoracic kyphosis (TK), pelvic incidence (PI), pelvic tilt (PT), and sacral slope (SS). To control for the individual variation of pelvic morphology, the LL/PI, PT/PI, and SS/PI ratios were calculated. Clinical outcome was assessed using the visual analog scale for pain, Oswestry Disability Index, and EQ-5D preoperatively and at a minimum 1-year follow-up. Correlation coefficients were calculated between each individual radiographic variable and the outcome measures. The importance of LL mismatch to TK, reflecting the importance of a harmonious spine, was analyzed by comparing the outcome of patients with a TK+LL+PI ≤ 45° to those with a sum > 45°.RESULTSSVA and T1SPI demonstrated the strongest correlation with the clinical outcome scores (r = 0.4–0.5, p < 0.001). LL correlated weakly with the clinical outcome (r = 0.2–0.3, p < 0.003). Mismatch of LL to PI, however, did not correlate significantly with the outcome. Similarly, only weak and inconsistent correlation was observed between PT, SS, PT/PI, SS/PI, and functional outcome. Patients with a TK+LL+PI ≤ 45° had a significantly lower ODI score (33 vs 44) and a significantly higher EQ-5D score (0.64 vs 0.40) than patients with a sum > 45° (LL is a negative value).CONCLUSIONSPSO resulted in a substantial correction of sagittal imbalance and improved outcome in most patients in this study. Correction of the global sagittal balance appears to be a necessary precondition for a good outcome. A harmonious spine with a TK and an LL of similar magnitude seems to add to a positive outcome.

scholarly journals Sagittal alignment and complications following lumbar 3-column osteotomy: does the level of resection matter?

2017 ◽  
Vol 27 (5) ◽  
pp. 560-569 ◽  
Author(s):  
Emmanuelle Ferrero ◽  
Barthelemy Liabaud ◽  
Jensen K. Henry ◽  
Christopher P. Ames ◽  
Khaled Kebaish ◽  
...  
Keyword(s):  
Lumbar Lordosis ◽  
Pelvic Tilt ◽  
Sagittal Alignment ◽  
Vertical Axis ◽  
Motor Deficits ◽  
Sagittal Vertical Axis ◽  
Spinopelvic Alignment ◽  
Alignment Correction ◽  
Caudal Level ◽  
The Impact

OBJECTIVEThree-column osteotomy (3CO) is a demanding technique that is performed to correct sagittal spinal malalignment. However, the impact of the 3CO level on pelvic or truncal sagittal correction remains unclear. In this study, the authors assessed the impact of 3CO level and postoperative apex of lumbar lordosis on sagittal alignment correction, complications, and revisions.METHODSIn this retrospective study of a multicenter spinal deformity database, radiographic data were analyzed at baseline and at 1- and 2-year follow-up to quantify spinopelvic alignment, apex of lordosis, and resection angle. The impact of 3CO level and apex level of lumbar lordosis on the sagittal correction was assessed. Logistic regression analyses were performed, controlling for cofounders, to investigate the effects of 3CO level and apex level on intraoperative and postoperative complications as well as on the need for subsequent revision surgery.RESULTSA total of 468 patients were included (mean age 60.8 years, mean body mass index 28.1 kg/m2); 70% of patients were female. The average 3CO resection angle was 25.1° and did not significantly differ with regard to 3CO level. There were no significant correlations between the 3CO level and amount of sagittal vertical axis or pelvic tilt correction. The postoperative apex level significantly correlated with greater correction of pelvic tilt (2° per more caudal level, R = −0.2, p = 0.006). Lower-level 3CO significantly correlated with revisions for pseudarthrosis (OR = 3.88, p = 0.001) and postoperative motor deficits (OR = 2.02, p = 0.026).CONCLUSIONSIn this study, a more caudal lumbar 3CO level did not lead to greater sagittal vertical axis correction. The postoperative apex of lumbar lordosis significantly impacted pelvic tilt. 3CO levels that were more caudal were associated with more postoperative motor deficits and revisions.

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

Neurosurgery ◽  
2017 ◽  
Vol 83 (4) ◽  
pp. 651-659 ◽  
Author(s):  
Peter G Passias ◽  
Cyrus M Jalai ◽  
Virginie Lafage ◽  
Renaud Lafage ◽  
Themistocles Protopsaltis ◽  
...  
Keyword(s):  
Thoracic Kyphosis ◽  
Treatment Strategies ◽  
Vertical Axis ◽  
Compensatory Mechanisms ◽  
Sagittal Vertical Axis ◽  
Cervical Deformity ◽  
T1 Slope ◽  
Significant Difference ◽  
Lowest Instrumented Vertebra ◽  
The Impact

Abstract 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 &lt; .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 &lt; .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.

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