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Background: Previous research on spinal alignment and postoperative outcomes after cervical and upper thoracic fixation has suggested that clinical and patient-reported outcomes are improved when certain anatomical parameters are maintained. These parameters include the cervical sagittal vertical axis (cSVA), C2 and T1 slopes, and cervical lordosis (CL). For patients with primary and metastatic tumors involving the subaxial cervical and/or upper thoracic spine, there is minimal guidance on how to apply these parameters. Surgeons must make critical decisions when designing the optimal construct, considering patient life expectancy, bone quality, oncology goals and deformity. This study aims to evaluate the impact of cervical spine alignment parameters on postoperative hardware failure in spine tumor patients and highlight instances of complications in patients with instrumentation crossing the cervicothoracic junction (CTJ). Methods: A retrospective review of a single institutional spine tumor database identified seventeen patients who underwent spinal fusion crossing the CTJ from 2015 to 2023. All patients had postoperative neutral standing radiographs with measurable cSVA, C2 and T1 slopes, and/or CL. The primary endpoint was instrumentation failure, defined as hardware pull out or breakage, and secondary endpoints included other complications including wound infection and spinal fluid leak. Results: The number of instrumented levels ranged from 3 to 15 segments with a mean of 7.47. Surgical approaches included anterior (n=3), posterior (n=12), and simultaneous anterior and posterior (n=2). The mean cSVA was 3.39±1.02 cm (range 1.59–4.9 cm). Fourteen patients had measurable C2 slopes with a mean of 25.03±9.16° (range 8.7 - 38.6°). Ten patients had measurable T1 slopes with a mean of 31.5±11.54° (range 18.4–59.6°). Thirteen patients had a measurable CL with a mean of 9.13±9.93° (range 0–37.5°). No cases of instrumentation failure were noted. Four patients experienced other postoperative complications (24%), but rates did not vary with increasing deviation from ideal parameters for cSVA, C2 and T1 slope, or CL. Conclusions: Although there was wide variability in alignment parameters in this cohort, there were no instances of hardware failure with crossing the CTJ at a mean follow-up of 41 months. The overall complication rate was high at 24%. Despite common concerns about the impact of exaggerated slope and SVA on instrumentation failure these results suggest that cervical and upper thoracic tumor patients may still have a satisfactory result following CTJ fixation, even with unfavorable alignment parameters. Larger prospective studies are needed.

Abstract Background The compensatory mechanisms for cervical lordosis change after laminectomy with fusion was not clear. The objective of this study was to evaluate the compensatory behaviors for cervical lordosis change after laminectomy with fusion. Methods This was a retrospective radiological analysis of 43 patients with cervical spondylotic myelopathy who underwent laminectomy with fusion (LCF). The following cervical parameters were measured: C2-7 Cobb angle (C2-7), occiput-C2 angle (O-C2), the cervical sagittal vertical axis (cSVA), and T1 slope (T1S). The difference was calculated for all angle parameters between the two time points using the following formula: the amount of change (Δ) = (value at the follow-up)—(preoperative value). Non-parametric tests and the t-test were used to compare the difference. The Pearson correlation test was performed, and stepwise multiple regression analysis was performed to determine the best correlation between ∆cSVA and ∆T1S. Results The mean age of 43 patients was 65.51 ± 9.80 years. All patients were classified into two subgroups based on ΔcSVA: Group M (maintained) and, Group I (increased). The preoperative O-C2, C2-7, T1S, and cSVA were similar between Group M and group I (p = 0.950, p = 0.731, p = 0.372, and p = 0.152, respectively). Postoperative O-C2 and postoperative cSVA were significantly different (p = 0.036 and p = 0.004, respectively). ∆O-C2, ∆T1S and ∆cSVA were significantly different between the two groups (p = 0.006, p = 0.000, and p = 0.000, respectively). ΔcSVA had significant correlations with ΔO-C2 neutral angle (r = 0.377) and ΔT1S (r = 0.582). A linear regression equation was established: ΔcSVA = 0.602 + 0.103 * ΔT1S (R = 0.582, R2 = 0.339). Conclusions The decrease of TIS should be the first and foremost compensation for the loss of lordosis in C2-7 segments after LCF. When the change of T1S alone can not prevent the deterioration of cervical sagittal balance, further increases in the O-C2 segment occur.

ObjectiveCervical sagittal parameters have been widely used to predict clinical outcomes in patients with cervical spondylotic myelopathy (CSM). This study aims to coin a novel cervical sagittal parameter defined as the ratio of cervical sagittal vertical axis to T1 slope (CSVA/T1S) and to investigate the correlation between CSVA/T1S and postoperative HRQOL after laminoplasty.MethodsA total of 102 CSM patients treated with cervical laminoplasty from our database were retrospectively reviewed. All patients were followed up for >12 months. Radiological parameters were measured using lateral cervical radiographs, including occiput-C2 lordosis (OC2), cervical lordosis (CL), CSVA, and T1S. Clinical parameters included the Japanese Orthopedic Association (JOA) score, neck disability index (NDI), and JOA recovery rate. Patients were grouped by preoperative T1S, T1S-CL, and CSVA/T1S value, respectively. Clinical and radiological outcomes were compared between the groups.ResultsPatients with high CSVA/T1S had greater OC2 and CSVA but lower CL than those in the low CSVA/T1S group pre-and postoperatively. With respect to HRQOL results, the final NDI was 12.46 ± 9.11% in the low CSVA/T1S group, which was significantly lower than that in the high CSVA/T1S group (17.68 ± 8.81%, P = 0.040). Moreover, only CSVA/T1S was detected to be significantly correlated with final NDI (r = 0.310, P = 0.027). No significant correlation was found between clinical results and other cervical sagittal parameters, including T1S, CSVA, and T1S-CL.ConclusionsPreoperative CSVA/T1S was correlated with postoperative NDI in patients with CSM after cervical laminoplasty. Patients with low preoperative CSVA/T1S achieved better neurological function improvement after cervical laminoplasty. Cervical laminoplasty could be an appropriate choice for patients with lower preoperative CSVA/T1S.

Background: The compensatory mechanisms for cervical lordosis change after laminectomy with fusion was not clear. The objective of this study was to evaluate the compensatory behaviors for cervical lordosis change after laminectomy with fusion.Methods: This was a retrospective radiological analysis of 43 patients with cervical spondylotic myelopathy who underwent laminectomy with fusion (LCF). The following cervical parameters were measured: C2-7 Cobb angle (C2-7), occiput-C2 angle (O-C2), the cervical sagittal vertical axis (cSVA), and T1 slope (T1S). The difference was calculated for all angle parameters between the two time points using the following formula: the amount of change (Δ) = (value at the follow-up)-(preoperative value). Non-parametric tests and the t-test were used to compare the difference. The Pearson correlation test was performed, and stepwise multiple regression analysis was performed to determine the best correlation between ∆cSVA and ∆T1S.Results: The mean age of 43 patients was 65.51 ± 9.80 years. All patients were classified into two subgroups based on ΔcSVA: Group M (maintained) and, Group I (increased). The preoperative O-C2, C2-7, T1S, and cSVA were similar between Group M and group I (p = 0.950, p = 0.731, p = 0.372, and p = 0.152, respectively). Postoperative O-C2 and postoperative cSVA were significantly different (p = 0.036 and p = 0.004, respectively). ∆O-C2, ∆T1S and ∆cSVA were significantly different between the two groups (p = 0.006, p = 0.000, and p = 0.000, respectively). ΔcSVA had significant correlations with ΔO-C2 neutral angle (r = 0.377) and ΔT1S (r = 0.582). A linear regression equation was established: ΔcSVA = 0.602 + 0.103 * ΔT1S (R = 0.582, R2 = 0.339).Conclusions: The decrease of TIS should be the first and foremost compensation for the loss of lordosis in C2-7 segments after LCF. When the change of T1S alone can not prevent the deterioration of cervical sagittal balance, further increases in the O-C2 segment occur. [ABSTRACT FROM AUTHOR]

Study Design This was a prospective clinical study. Purpose Previous studies have indicated that cervical lordosis is a parameter influenced by segmental and global spinal sagittal balance parameters. However, this correlation still remains unclear. Therefore, a better understanding of the normal values and interdependencies between inter-segmental alignment parameters is needed. This is a preliminary analysis that helps to understand these factors. Overview of Literature Change in global sagittal alignment is associated with poor health-related quality of life. Questions regarding which parameters play the primary roles in the progression of spinal sagittal imbalance and which might be compensatory factors remain unanswered. Methods Prospectively, 420 adults (105 asymptomatic, 105 cervical symptomatic, 105 lumbar symptomatic, and 105 post-surgical) were selected. Whole-spine standing lateral radiographs were taken, and spinopelvic, thoracic, and cervical parameters were measured. Then, the data were analyzed using correlation coefficient test and multiple regression analysis. Results All the parameters showed a normal distribution. The mean values of the cervical parameters are as follows: C1C2 Cobb angle, −27.07°±4.3°; C2C7 Cobb angle, −16.4°±5.6°; OCC2 Cobb angle, −14.5°±3.8°; OCC7 Cobb angle, −29.8°±5.6°; C2C7 Harrison angle, 20.4°±4.3°; and C7 slope, −25.4°±5.6°. The analysis of these parameters revealed no statistically significant difference between asymptomatic, symptomatic, and post-surgical patients. C7 sagittal vertical axis (SVA) correlated with the C2C7 Cobb angle (r=0.7) in all groups. No significant correlation was noted between cervical and spinopelvic parameters in asymptomatic patients. However, C1C2 Cobb angle correlated significantly with pelvic incidence (PI, r=−0.2), lumbar lordosis (LL, r=0.2), and pelvic tilt (PT, r=−0.2) in cervical symptomatic patients. Irrespective of the patient symptom sub-group (n=420), C1C2 Cobb angle correlated with LL (r=0.1) and C2C7 Harrison angle correlated with PI and PT (r=0.1). Conclusions Our results indicate significant interdependence between the spinopelvic and cervical alignment, especially in cervical symptomatic patients. In addition, strong correlation was found between the C7 SVA and C2C7 Cobb angle. Overall, the results of this study could help to better understand the cervical sagittal alignment and serve as preliminary data for planning surgical reconstruction procedures.

Study Design This study is a post hoc analysis of a multicenter prospective randomized controlled trial which compared artificial disc replacement and anterior cervical discectomy and fusion. Purpose Useful radiographic parameters for assessing cervical alignment include the Cobb angles, T1 slope (T1S), occipitocervical inclination (OCI), K-line tilt (KLT), and cervical sagittal vertical axis (cSVA). This study aimed to determine measurement accuracy and reliability for these parameters. Overview of Literature Various authors have assessed repeatability by comparing different methods of measurement, but knowledge of measurement error and minimal detectable change is scarce. Methods We evaluated 758 lateral cervical radiographs. One medical student and one spine surgeon (i.e., measured ×2 within 4 weeks) independently measured the parameters obtaining 5,850 values. Standard error of measurement (SEm) and minimum detectable change (MDC) were calculated for each parameter. The accuracy and reliability of the Cobb angle measurements were calculated for the different types of angles: cervical lordosis, prosthesis angle, segmental angle with two bone surfaces (SABB), and segmental angle with one bone and one metal surface. Reliability was determined with intraclass correlation coefficient (ICC). Results SEm was 1.8° and MDC was 5.0° for the Cobb angle, with an intraobserver/interobserver ICC of 0.958/0.886. All the different subtypes of Cobb angles had an ICC higher than 0.950, except SABB (intraobserver/interobserver ICC of 0.922/0.716). The most accurate and reliable measurement was for KLT. Conclusions This study provides normative data on SEm and MDC for Cobb angles, T1S, KLT, OCI, and cSVA in cervical lateral radiographs. Reliability was excellent for all parameters except SABB (e.g., good).

Anterior cervical discectomy and fusion (ACDF) can induce lordosis and improve cervical sagittal vertical axis (SVA), but multilevel ACDF may inadvertently increase cervical SVA because of insufficient lordosis induction. Patients who underwent 1-, 2-, or ≥3-level ACDF in the subaxial spine with minimum 2-year follow up were retrospectively studied. C2-C7 Cobb angle (lordosis), cervical SVA, and T1 slope were measured preoperatively, immediately postoperatively, and at last follow-up. Inclusion criteria were met by 127 patients. There were no differences in baseline demographics among 1-, 2-, and ≥3-level ACDF groups. Mean follow-up was 43.7 months (range, 24–142 months). Increase of cervical SVA immediately postoperatively was 1.94 mm, −1.44 mm, and 7.25 mm for 1-, 2-, and ≥3-level ACDF (P = 0.041) and at last follow-up was 2.97 mm, 0.70 mm, and 9.32 mm for 1-, 2-, and ≥3-level ACDF (P = 0.026). At last follow-up, 2-level ACDF patients had the greatest decrease in T1 slope (−0.43°) compared with increase of 2.71° for 1-level and 2.84° for ≥3-level patients (P = 0.028). In all 3 groups, segmental (ACDF levels) lordosis, cervical SVA, and T1 slope did not decrease from immediate postoperative to last follow-up. Only 2-level ACDF maintained C2-7 lordosis (2.16°) compared with loss of lordosis in 1-level (−0.84°) and ≥3-level (−2.00°) ACDF (P = 0.008) at last follow-up. Linear regression analysis showed that T1 slope had no relationship with correction of cervical SVA (P = 0.5310) but had a significant correlation with Cobb angle loss of C2-C7 lordosis (P = 0.0016). Compared with 1- and 2-level ACDF, ≥3-level ACDF resulted in significant increase of cervical SVA and loss of overall lordosis. Compared with 1- and ≥3-level ACDF, 2-level ACDF had the greatest ability to maintain lordosis. T1 slope had a significant correlation with loss of C2-C7 lordosis after ACDF. [ABSTRACT FROM AUTHOR]

Introduction: The aims of the present study were 1) to examine the association between neck and shoulder pain (NSP) and lifestyle in the general population and 2) to examine if sagittal spino-pelvic malalignment is more prevalent in NSP. Methods: A total of 107 volunteers (mean age, 64.5 years) were recruited in this study from listings of resident registrations in Kihoku region, Wakayama, Japan. Feeling pain or stiffness in the neck or shoulders was defined as an NSP. The items studied were: 1) the existence or lack of NSP and their severity (using VAS scale), 2) Short Form-36 (SF-36), 3) Self-Rating Questionnaire for Depression (SRQ-D), 4) Pain Catastrophizing Scale (PCS), 5) a detailed history consisting of 5 domains as being relevant to the psychosocial situation of patients with chronic pain, 6) A VAS of pain and numbness to the arm, and from thoracic region to legs. The radiographic parameters evaluated were also measured. Participants with a VAS score of 40 mm or higher and less were divided into 2 groups. Association of SF-36, SRQ-D, and PCS with NSP were assessed using multiple regression analysis. Results: In terms of QoL, psychological assessment and a detailed history, bodily pain in SF-36, SRQ-D, and family stress were significantly associated with NSP. A VAS of pain and numbness to the arm, and from thoracic region to legs, was significantly associated with NSP. There were no statistical correlations between the VAS and radiographic parameters of the cervical spine. Among the whole spine sagittal measurements, multiple logistic regression analysis showed that sacral slope (SS) and sagittal vertical axis (SVA) were significantly associated with NSP. Conclusion: In this study, we showed the factors associated with NSP. Large SS and reduced SVA were significantly associated with NSP, while cervical spine measurements were not.

Study Design: This was a prospective clinical study. Purpose: Previous studies have indicated that cervical lordosis is a parameter influenced by segmental and global spinal sagittal balance parameters. However, this correlation still remains unclear. Therefore, a better understanding of the normal values and interdependencies between inter-segmental alignment parameters is needed. This is a preliminary analysis that helps to understand these factors. Overview of Literature: Change in global sagittal alignment is associated with poor health-related quality of life. Questions regarding which parameters play the primary roles in the progression of spinal sagittal imbalance and which might be compensatory factors remain unanswered. Methods: Prospectively, 420 adults (105 asymptomatic, 105 cervical symptomatic, 105 lumbar symptomatic, and 105 post-surgical) were selected. Whole-spine standing lateral radiographs were taken, and spinopelvic, thoracic, and cervical parameters were measured. Then, the data were analyzed using correlation coefficient test and multiple regression analysis. Results: All the parameters showed a normal distribution. The mean values of the cervical parameters are as follows: C1C2 Cobb angle, -27.07°±4.3°; C2C7 Cobb angle, -16.4°±5.6°; OCC2 Cobb angle, -14.5°±3.8°; OCC7 Cobb angle, -29.8°±5.6°; C2C7 Harrison angle, 20.4°±4.3°; and C7 slope, -25.4°±5.6°. The analysis of these parameters revealed no statistically significant difference between asymptomatic, symptomatic, and post-surgical patients. C7 sagittal vertical axis (SVA) correlated with the C2C7 Cobb angle (r =0.7) in all groups. No significant correlation was noted between cervical and spinopelvic parameters in asymptomatic patients. However, C1C2 Cobb angle correlated significantly with pelvic incidence (PI, r =-0.2), lumbar lordosis (LL, r =0.2), and pelvic tilt (PT, r =-0.2) in cervical symptomatic patients. Irrespective of the patient symptom sub-group (n=420), C1C2 Cobb angle correlated with LL (r =0.1) and C2C7 Harrison angle correlated with PI and PT (r =0.1). Conclusions: Our results indicate significant interdependence between the spinopelvic and cervical alignment, especially in cervical symptomatic patients. In addition, strong correlation was found between the C7 SVA and C2C7 Cobb angle. Overall, the results of this study could help to better understand the cervical sagittal alignment and serve as preliminary data for planning surgical reconstruction procedures. [ABSTRACT FROM AUTHOR]

Study Design: This study is a post hoc analysis of a multicenter prospective randomized controlled trial which compared artificial disc replacement and anterior cervical discectomy and fusion. Purpose: Useful radiographic parameters for assessing cervical alignment include the Cobb angles, T1 slope (T1S), occipitocervical inclination (OCI), K-line tilt (KLT), and cervical sagittal vertical axis (cSVA). This study aimed to determine measurement accuracy and reliability for these parameters. Overview of Literature: Various authors have assessed repeatability by comparing different methods of measurement, but knowledge of measurement error and minimal detectable change is scarce. Methods: We evaluated 758 lateral cervical radiographs. One medical student and one spine surgeon (i.e., measured ×2 within 4 weeks) independently measured the parameters obtaining 5,850 values. Standard error of measurement (SEm) and minimum detectable change (MDC) were calculated for each parameter. The accuracy and reliability of the Cobb angle measurements were calculated for the different types of angles: cervical lordosis, prosthesis angle, segmental angle with two bone surfaces (SABB), and segmental angle with one bone and one metal surface. Reliability was determined with intraclass correlation coefficient (ICC). Results: SEm was 1.8° and MDC was 5.0° for the Cobb angle, with an intraobserver/interobserver ICC of 0.958/0.886. All the different subtypes of Cobb angles had an ICC higher than 0.950, except SABB (intraobserver/interobserver ICC of 0.922/0.716). The most accurate and reliable measurement was for KLT. Conclusions: This study provides normative data on SEm and MDC for Cobb angles, T1S, KLT, OCI, and cSVA in cervical lateral radiographs. Reliability was excellent for all parameters except SABB (e.g., good). [ABSTRACT FROM AUTHOR]

Objective To explore the appropriate range of C0–C2 correction angles by analyzing cervical sagittal alignment parameters and evaluating clinical outcomes. Methods The preoperative and postoperative radiographs, visual analogue scale, Japanese Orthopedic Association score, and neck disability index of 65 atlantoaxial dislocation patients were retrospectively collected. The C0–C2 angle, C2–C7 angle, and cervical sagittal vertical axis (cSVA) were measured from the radiographs, and an assessment of cervical degenerative disc disease was made. According to the 2-year postoperative C0–C2 angles, all patients were categorized into a <10° subgroup, 10°–20° subgroup, and >20° subgroups. Results The postoperative C2–C7 angles and cSVA of the 10°–20° subgroup were significantly different from those of the <10° subgroup. The Japanese Orthopedic Association score of the 10°–20° subgroup was significantly different from those of the <10° and >20° subgroups. All patients (26/26) in the 10°–20° subgroup exhibited a cSVA 0–40 mm, 25% of patients (6/24) in the >20° subgroup exhibited a cSVA >40 mm, and 40% of patients (6/15) in the <10° subgroup showed a cSVA <0 mm. The postoperative incidence of cervical degenerative disc disease did not increase in the 10°–20° subgroup. Conclusions Atlantoaxial dislocation patients with different C0–C2 postoperative angles had different cervical sagittal alignments and clinical outcomes. In our study, the patients within the C0–C2 10°–20° subgroup exhibited superior clinical outcomes and cervical sagittal alignment. [ABSTRACT FROM AUTHOR]

Background Context: Cervical sagittal vertical axis (cSVA) of ≥40 mm is recognized as the key factor of poor health-related quality of life, poor surgical outcomes, and correction loss after surgery for cervical deformity. However, little is known about the radiological characteristics of patients with cSVA≥40 mm.Purpose: The purpose of this study was to identify the radiological characteristics of patients with cervical imbalance.Design: Retrospective analysis of weight-bearing cervical magnetic resonance (MR) images.Patient Sample: Consecutive 1,500 MR images of symptomatic patients in weight-bearing position.Outcome Measures: Cervical sagittal vertical axis, cervical alignment, cervical balance parameters (T1 slope, Co-C2 angle, C2-C7 angle, C7-T1 angle, neck tilt, and thoracic inlet angle), disc degeneration (Pfirmann and Suzuki classification), end plate degeneration (Modic change), spondylolisthesis (antero- and retrolisthesis), anteroposterior (AP) diameter of dural sac, cross-sectional area (CSA), and fat infiltration ratio of the transversospinalis muscles at C4 and C7 levels.Methods: Patients were divided into two groups: cSVA≥40 mm and cSVA<40 mm. Gender, age, and cervical alignment were analyzed. Subsequently, matched imbalance (cSVA≥40 mm) and control (<40 mm) groups were created using the propensity score to adjust for age, gender, and cervical alignment. Cervicothoracic angular parameters, disc degeneration, Modic change, spondylolisthesis, and degeneration of the transversospinalis muscles at C4 and C7 were compared. Variables with p<.05 were included in the multinomial logistic regression model to identify factors that relate to the cervical balance grouping.Results: The incidence of patients with cervical imbalance was 2.5% (37 patients). Those patients had a higher incidence of kyphosis, were older, and there were more male patients. In the matched imbalance group, the T1 slope was greater (p=.028), C7-T1 lordotic angle was smaller (p<.001), the number of anterolisthesis was greater (p=.012), and the fat infiltration ratio at C4 and C7 was higher (p=.023, 0.030) compared with the control. Logistic regression analysis showed that the C7-T1 angle (adjusted odds ratio [aOR]=0.592, p=.001) and fat infiltration ratio at C7 level (aOR=1.178, p=.030) were significant independent variables.Conclusions: Smaller C7-T1 lordotic angle and severe muscle degeneration at C7 level were independent characteristics of patients with cervical imbalance. [ABSTRACT FROM AUTHOR]

Objective: The C2 slope (C2S) is one of the parameters that can determine cervical sagittal alignment, but its clinical significance is relatively unexplored. This study aimed to evaluate the clinical significance of the C2S after multilevel cervical spine fusion., Methods: A total of 111 patients who underwent multilevel cervical spine fusion were included in this study. The C2S, cervical sagittal vertical axis (cSVA), C2-7 lordosis, and T1 slope (T1S) were measured in standing lateral cervical spine radiographs preoperatively and 2 years after the surgery. Clinical outcome measures were visual analog scale (VAS) neck and arm pain scores, Neck Disability Index (NDI), Japanese Orthopaedic Association (JOA) scale score, and patient-reported subjective improvement rate (IR) percentage. Statistical analysis was performed using a paired-samples t-test and Pearson's correlation, and a receiver operating characteristic (ROC) curve to determine the cutoff values of C2S., Results: C2S demonstrated a significant correlation with the cSVA, C2-7 lordosis, T1S, and T1S minus cervical lordosis. C2S revealed a significant correlation with the JOA, neck pain VAS, and NDI scores at 2 years after surgery. Change in the C2S correlated with postoperative neck pain and NDI scores. ROC curves demonstrated the cutoff values of C2S as 18.8°, 22.25°, and 25.35°, according to a cSVA of 40 mm, severe disability expressed by NDI, and severe myelopathy, respectively., Conclusions: C2S can be an additional cervical sagittal alignment parameter that can be a useful prognostic factor after multilevel cervical spine fusion.

OBJECTIVEComplete radiographic and clinical evaluations are essential in the surgical treatment of cervical spondylotic myelopathy (CSM). Prior studies have correlated cervical sagittal imbalance and kyphosis with disability and worse health-related quality of life. However, little is known about C2-3 disc angle and its correlation with postoperative outcomes. The present study is the first to consider C2-3 disc angle as an additional radiographic predictor of postoperative adverse events.METHODSA retrospective chart review was performed to identify patients with CSM who underwent surgeries from 2010 to 2014. Data collected included demographics, baseline presenting factors, and postoperative outcomes. Cervical sagittal alignment variables were measured using the preoperative and postoperative radiographs. Univariable logistic regression analyses were used to explore the association between dependent and independent variables, and a multivariable logistic regression model was created using stepwise variable selection.RESULTSThe authors identified 171 patients who had complete preoperative and postoperative radiographic and outcomes data. The overall rate of postoperative adverse events was 33% (57/171), and postoperative C2-3 disc angle, C2-7 sagittal vertical axis, and C2-7 Cobb angle were found to be significantly associated with adverse events. Inclusion of postoperative C2-3 disc angle in the analysis led to the best prediction of adverse events. The mean postoperative C2-3 disc angle for patients with any postoperative adverse event was 32.3° ± 17.2°, and the mean for those without any adverse event was 22.4° ± 11.1° (p < 0.0001).CONCLUSIONSIn the present retrospective analysis of postoperative adverse events in patients with CSM, the authors found a significant association between C2-3 disc angle and postoperative adverse events. They propose that C2-3 disc angle be used as an additional parameter of cervical spinal sagittal alignment and predictor for operative outcomes.

Objective: A high prevalence of cervical deformity (CD) has been identified among adult patients with thoracolumbar spinal deformity undergoing surgical treatment. The clinical impact of this is uncertain. This study aimed to quantify the differences in patient-reported outcomes among patients with adult spinal deformity (ASD) based on presence of CD prior to treatment., Methods: A retrospective review was conducted of a multicenter prospective database of patients with ASD who underwent surgical treatment with 2-year follow-up. Patients were grouped by the presence of preoperative CD: 1) cervical positive sagittal malalignment (CPSM) C2-7 sagittal vertical axis ≥ 4 cm; 2) cervical kyphosis (CK) C2-7 angle > 0; 3) CPSM and CK (BOTH); and 4) no baseline CD (NONE). Health-related quality of life (HRQOL) scores included the Physical Component Summary and Mental Component Summary (PCS and MCS) scores of the 36-Item Short Form Health Survey (SF-36), Oswestry Disability Index (ODI), Scoliosis Research Society-22 questionnaire (SRS-22), and minimum clinically important difference (MCID) of these scores at 2 years. Standard radiographic measurements were conducted for cervical, thoracic, and thoracolumbar parameters., Results: One hundred eighty-two patients were included in this study: CPSM, 45; CK, 37; BOTH, 16; and NONE, 84. Patients with preoperative CD and those without had similar baseline thoracolumbar radiographic measurements and similar correction rates at 2 years. Patients with and without preoperative CD had similar baseline HRQOL and on average both groups experienced some HRQOL improvement. However, those with preoperative CPSM had significantly worse postoperative ODI, PCS, SRS-22 Activity, SRS-22 Appearance, SRS-22 Pain, SRS-22 Satisfaction, and SRS-22 Total score, and were less likely to meet MCID for ODI, PCS, SRS-22 Activity, and SRS-22 Pain scores with the following ORs and 95% CIs: ODI 0.19 (0.07-0.58), PCS 0.17 (0.06-0.47), SRS-22 Activity 0.23 (0.09-0.62), SRS-22 Pain 0.20 (0.08-0.53), and SRS-22 Appearance 0.34 (0.12-0.94). Preoperative CK did not have an effect on outcomes. Interestingly, despite correction of the thoracolumbar deformity, 53.3% and 51.4% of patients had persistent CPSM and persistent CK, respectively., Conclusions: Patients with thoracolumbar deformity without preoperative CD are likely to have greater improvements in HRQOL after surgery than patients with concomitant preoperative CD. Cervical positive sagittal alignment in adult patients with thoracolumbar deformity is strongly associated with inferior outcomes and failure to reach MCID at 2-year follow-up despite having similar baseline HRQOL to patients without CD. This was the first study to assess the impact of concomitant preoperative cervical malalignment in adult patients with thoracolumbar deformity. These results can help surgeons educate patients at risk for inferior outcomes and direct future research to identify an etiology and improve patient outcomes. Investigation into the etiology of the baseline cervical malalignment may be warranted in patients who present with thoracolumbar deformity.