Correlation of radiographic and functional measurements in patients who underwent primary scoliosis surgery in adult age

Cervical Sagittal Alignment and Balance Associated With Aging Chinese Adults: A Radiographic Analysis

STUDY DESIGN

This was a retrospective cohort radiographic study.

OBJECTIVE

To determine the age- and gender-related normative values and correlation of cervical sagittal parameters in asymptomatic Chinese adults, and to explore the changes and compensating mechanisms across different age groups.

METHODS

The asymptomatic subjects were divided into 6 groups according to age and then one-way analysis of variance was used to compare the multiple sets of cervical sagittal parameters among the different age groups. Independent t-tests were performed to compare the sagittal parameters among different gender and different cervical spine alignments. Relationships between each parameter were tested by Pearson's correlation. Linear regression analysis based on T1 slope (T1S) and C2 slope (C2S) was used to provide an equation to predict normal cervical alignment.

RESULTS

Mean values of each cervical sagittal parameter were presented based on age and gender. There were positive correlations between age and cervical lordosis (CL) (r = -.278, P < .001), T1S (r = .271, P < .001), cervical sagittal vertical axis (cSVA) (r = .218, P < .001), C2-C4 Cobb angle (r = -.283, P < .001), horacic inlet angle (TIA) (r = .443, P < .001), and neck tilt (NT) (r = .354, P < .001). Older groups (aged >50 years) had greater T1 Slope, C2S, and TIA. The C2-C4 Cobb angle maintained a steadily increasing trend and significantly increased in the older adult groups (P < .05), while the C5-C7 Cobb angle was relatively constant. Mean values of parameters were larger in males (P > .05). Linear regression analysis indicated a strong association between T1S and CL (R2 = .551, standard error 1.16°), T1S and C5-7 (R2 = .372; P < .001), and C2S and C2-4 (R2 = .309; P < .001).

CONCLUSIONS

Normative values of cervical sagittal parameters vary by age and sex. The CL, cSVA, and T1S, C2-4 Cobb angle changed with increasing age, and it can influence the recruitment of compensation mechanism. Normative CL of Chinese adults was predicted by the equation CL = T1S-14.7° ± 1.2°, which could serve as a reference when planning for cervical surgery.

Sagittal reduction of spinal deformity: Superior versus lateral screw-rod connection

INTRODUCTION

Spinal malalignment can greatly impact a patient's quality of life. Various sagittal parameters are used as realignment goals; however, about 50% of patients end up being under-corrected postoperatively. To improve the correction, prebent rods are available with a radius of curvature corresponding to the patient's "ideal" sagittal alignment. But no studies have been done on how the radius of curvature changes according to the type of connection between the pedicle screws and rods. The goal of this experimental study was to quantify how much prebent rods flatten based on the method used to connect the screw and rod: top-loading screw vs. dome screw with lateral connector.

METHODS

The experiment was done on a material testing system in axial compression on three constructs consisting of two rods secured with top-loading screws and three other constructs consisting of two rods secured with dome screws and lateral connector. The maximum angle of the construct was measured during loading and after removing the load. The primary outcome measure was the mean angle in each construct at each step.

RESULTS

The mean angle of the constructs with top-loading screws when subjected to 500 N load was significantly less than in the constructs with dome screws and lateral connector: 18.6° vs. 24.5° respectively (p<0.0003). The mean angle of the constructs with top-loading screws after removing the load was significantly less than in the constructs with dome screws and lateral connector: 25.7° vs. 32.3° respectively, (p<0.0005).

CONCLUSION

In vitro, top-loading screws produced significantly greater flattening than dome screws with lateral connector. These findings must be confirmed in vivo. Understanding the behavior of rods as a function of the type of screw connection can be an important factor to minimize the risk of under-correction in the sagittal plane.

LEVEL OF EVIDENCE

III.

The Relationship of Kinesiophobia with Pain and Quality of Life in Idiopathic Scoliosis

STUDY DESIGN

Prospective, multi-centric, cross-sectional study.

OBJECTIVE

To analyze the construct validity of the Tampa Scale of Kinesiophobia (TSK) in a cohort of patients with adolescent idiopathic scoliosis (AIS).

SUMMARY OF THE BACKGROUND DATA

Back pain is not uncommon in AIS. The fear of movement (kinesiophobia) in response to pain is related to back pain. TSK psychometric properties in AIS patients have not been properly analyzed.

METHODS

Patients with AIS and no prior spine surgery were prospectively included. They fulfilled the Spanish version of the TSK-11 questionnaire, a pain intensity numerical rating scale (NRS), refined SRS-22 (SRS-22r), the Hospital Anxiety and Depression Scale (HADS), and item 7 of the Core Outcome Measurement Index (COMI). The sample was split into two groups for the statistical analysis: adolescents and young adults. Cronbach alpha was used to assess internal consistency. Discriminant and concurrent validity were obtained by computing Pearson correlation coefficients between the TSK score and several criterion measures.

RESULTS

A total of 275 patients were included-198 adolescents (mean age of 14.6 yrs) and 77 young adults (mean age of 26.9 yrs). The Cobb of largest curve means were 44.9° and 48.9°, respectively. In the adolescent group, the TSK mean (±SD) was 21.5 (±5.93), with a floor effect of 2.5%. In the adult group, the TSK mean was 24.2 (±6.63), with a floor effect of 3.9%. The ceiling effect was 0% in both groups. Cronbach alphas for the adolescent and adult groups were 0.76 and 0.79, respectively. No correlation was found in any group between the TSK score and the curve magnitude or pattern (Lenke classification). The TSK was significantly correlated with HAD depression and SRS-22r in both groups. However, these correlations were weaker in adolescents. In adults, the TSK also significantly correlates with NRS and work/school absenteeism.

CONCLUSION

The Spanish version of TSK-11 is a reliable and valid instrument to analyze kinesiophobia in AIS. However, the weak correlation between kinesiophobia and pain intensity, disability, and emotional condition in adolescents requires further study.Level of Evidence: 4.

Photographic sagittal plane analysis and its clinical correlation after surgery for adult spinal deformity: a preliminary study

PURPOSE

The aim of this study is to determine the correlation between photographic sagittal parameters and patient-reported outcome measures (PROM) results in adult patients operated on spinal deformity.

METHODS

Non-concurrent prospective study.

INCLUSION CRITERIA

age at surgery older than 25, minimum 2-year follow-up after a 5 or more level fusion for adult spinal deformity (ASD). Full body lateral standing photographs were taken with adhesive markers placed on ten bony landmarks. SRS-22 and SF-36 questionnaires were completed for every patient. The following photographic parameters were measured: lumbar angle, lumbar curve, thoracic inclination (TI), trunk angle, pelvic tilt, head angle, neck angle, cervicothoracic angle, lumbar vector angle (LVA), dorsal vector angle (DVA), cervical vector angle (CVA), cranial pelvic angle (CrPA), cranial sacral angle (CrSA), fibular inclination angle (FIA) and cranial sagittal vertical axis measured to sacrum (Cr-S), greater trochanter (Cr-GT), knee (Cr-K) and ankle (Cr-A).

RESULTS

65 patients (58 female) operated on ASD in a single institution were included. Age at surgery was 61 years (26-67). Postoperative follow-up was 53 months (24-120). Spearman rank order test showed several significant (p ≤ 0.01) correlations. After multivariate linear regression analysis age, LVA and TI remained as predictors for SRS image scores (corrected r² 0.41), LVA for SRS satisfaction (corrected r² 0.27), CrPA and age for SRS total scores (corrected r² 0.33), FIA and age for SF36 physical functioning (corrected r² 0.36) and CrSA for SF36 role physical (corrected r² 0.14).

CONCLUSIONS

Some sagittal photographic parameters may predict mid-term clinical results after ASD surgery.

Optimal indicators for identification of compensatory sagittal balance in patients with degenerative disc disease

Study design

A retrospective study.

Background

To determine whether radiological parameters such as maximal lumbar lordosis-maximal thoracic kyphosis (maxLL-maxTK), sacral slope-pelvic tilt(SS-PT) and sacral slope/pelvic tilt (SS/PT) could be used as indicators for the diagnosis of degenerative disc disease (DDD) in compensatory sagittal balanced patients.

Methods

Medical records of sagittal balanced DDD patients and asymptomatic adults within our hospital registry from July 2019 to November 2019 were reviewed. General characteristics and radiological parameters were evaluated between the two groups. Analysis of covariance with age as a covariate was conducted, followed by receiver operating characteristic (ROC) analysis and areas under the curve (AUC) calculation. The max Youden index was calculated to identify the optimal sensitivity specificity pairs.

Results

A total of 42 DDD patients and 199 asymptomatic adults were included. For those parameters that showed significant differences between the two groups, AUC for SS/PT and SS-PT were the largest, reaching 0.919 and 0.936, respectively. The sensitivity was 0.749, the specificity was 0.952 and the max Youden index was 0.701 when SS/PT = 1.635 was used as threshold. The max Youden index was found for a threshold of SS-PT =8.500, for which the sensitivity increased to 0.854, while the specificity decreased to 0.857.

Conclusions

Both SS/PT and SS-PT were significantly different between sagittal balanced DDD patients and asymptomatic adults. SS/PT < 1.6 and SS-PT < 8.5 could be used as indicators for the diagnosis of DDD patients with compensatory sagittal balance.

Is the Cranial Sagittal Vertical Axis (Cr-SVA) a Better Midterm Predictor of Clinical Results Than C7-SVA in Adult Patients Operated on Spinal Deformity After a Minimum 2-Year Follow-Up?

STUDY DESIGN

This is nonconcurrent prospective study approved by the Institutional Research Ethics Committee.

OBJECTIVE

The purpose of this study is to determine if the cranial sagittal vertical axis (Cr-SVA) measured in full spine standing radiographs is a better predictor of clinical results than the C7 sagittal vertical axis (C7-SVA) in adult patients operated on spinal deformity with a minimum 2-year follow-up after surgery.

SUMMARY OF BACKGROUND DATA

The Cr-SVA has recently been described as a better predictor of health-related quality of life outcomes than the C7-SVA for patients with adult spinal deformity (ASD) before undergoing surgery. This has not been confirmed in patients after ASD surgery.

METHODS

Inclusion criteria were age at surgery more than 25 years and a minimum 2-year follow-up after a ≥5 level fusion for ASD. Full-length standing lateral radiographs (including nasion-inion line, spine, and femoral heads) and Scoliosis Research Society 22 Questionnaire and SF36 questionnaires were available for every patient at the final follow-up. The distance from the Cr-SVA to the posterior corner of S1 (Cr-SVA-S) and to the centers of the hip (Cr-SVA-H) was measured and also the C7-SVA, lumbar lordosis, pelvic incidence, pelvic tilt, and PI-LL.

RESULTS

Sixty-five patients (58 female individuals) operated on ASD in a single institution were included. Age at surgery was 61 years (26-67). The mean follow-up was 53 months (24-120). Spearman rank-order test showed several significant correlations. After multivariable analysis, only Cr-SVA-S and age persisted as predictors for Scoliosis Research Society (SRS) image scores, Cr-SVA-H for SRS satisfaction, Cr-SVA-H and age for SRS total scores, Cr-SVA-H and age for SF36 Physical Function, Cr-SVA-S for SF36 Role Physical, Cr-SVA-H for SF36 Bodily Pain, and Cr-SVA-H for SF36 Role Emotional.

CONCLUSIONS

The Cr-SVA measured in full spine standing radiographs seems to be a better predictor of health-related quality of life outcomes than the C7-SVA for adults operated on spinal deformity >2 years after surgery.

Does Clinical Photography Influence Satisfaction With Surgery in Adult Patients Operated on for Spinal Deformity?

BACKGROUND

Recently published data suggest that showing patients operated on for adolescent idiopathic scoliosis or kyphosis their preoperative and postoperative photographs may enhance their satisfaction and self-image as measured by Scoliosis Research Society Health-Related Quality of Life Questionnaire (SRS-22) scores. No data exist for adult spinal deformity (ASD) surgery. The aim of this study is to determine the effect on patient postoperative satisfaction and self-image of showing adult deformity patients their preoperative and postoperative whole body photographs.

METHODS

This was a nonconcurrent prospective study. Patients operated on for ASD with a minimum 2-year postoperative follow-up who had preoperative full-body photographs taken by a professional photographer were included. Two follow-up visits were arranged 7 days apart. In the first visit, patients completed the SRS-22 questionnaire, and full-body standing photographs were taken. In the second visit, patients were asked to complete again questions 4, 6, 10, 14, 19 (self-image), 21, and 22 (satisfaction) of the SRS-22 after seeing their preoperative and postoperative full-body photographs.

RESULTS

Thirty patients (28 female) were included. The median age at surgery was 50 years (26-76). The median follow-up was 51 months (24-120). SRS-22 results at first visit were: activity 2.79 ± 0.75; self-image 2.71 ± 0.82; pain 2.53 ± 1.10; mental health 3.08 ± 0.77; satisfaction 3.46 ± 1.20; global 2.74 ± 0.72. SRS22 results at second visit were: self-image 2.9 ± 0.75; satisfaction 4.02 ± 0.97. After seeing the preoperative and final follow-up photographs, patients experienced an improvement in SRS-22 self-image (P = .000) and satisfaction domains (P = .011).

CONCLUSIONS

In patients operated on for ASD, showing preoperative and postoperative photographs improves patient satisfaction with surgery and self-image.

LEVEL OF EVIDENCE

3.

CLINICAL RELEVANCE

Our results could be a starting point for introducing full-body clinical photographs as a routine clinical tool in adult deformity patients undergoing surgery.

Sagittal alignment based on inflection point and its differences according to age groups

PURPOSE

We have always used the standard anatomical landmark vertebrae to measure the sagittal alignment. Instead, scoliosis has been evaluated by the end vertebrae in the coronal plane. There have been clinical studies to investigate sagittal alignment on the end vertebrae of inflection points (IPs). The purpose is to determine sagittal alignment based on IPs and to elucidate the changes while considering age groups.

METHODS

We identified the most titled vertebrae in the sagittal plane to define the end vertebrae of S1, thoracolumbar and cervicothoracic IPs and to measure the Cobb angles of sacral slope, functional lumbar, thoracic, cervical segment between them, and the McGregor's line, and the IP distances from the C2 plumb line to the point bisecting the upper end plate of the IPs, in addition to S1.

RESULTS

The most common thoracolumbar and cervicothoracic IPs were L2 and T1, respectively. However, the next most common cervicothoracic IP changed from T2 in the youngest to C7 in the oldest age group. The sagittal angles decreased at the sacral slope and functional lumbar segment but not the functional thoracic segment and functional cervical segment. Similarly, the distance increased at the C2 sagittal vertical axis (SVA) distance to S1 and thoracolumbar IP distance but not at the cervicothoracic IP distance. There was no difference in the pelvic incidence among age groups.

CONCLUSION

The sagittal Cobb angles based on the IPs decreased at the sacral slope and functional lumbar segment in the older adults. Consequently, the C2 SVA distance to S1 and thoracolumbar IP distance increased.

The differences in whole-body sagittal alignment between different postures in young, healthy adults

Study design

Prospective study.

Objective

To identify the radiographic differences between the standard upright position and the natural and comfortable upright position.

Methods

The radiographic data of 50 young and healthy adults were evaluated, and parameters including the global cervical angle (GCA), global thoracic angle (GTA), global lumbar angle (GLA) were used to depict the spine profile; the distance from the cranial center to the posterior corner of S1 (CSVA-S), the center of the hip (CSVA-H), the center of the knee (CSVA-K) and the center of the ankle (CSVA-A) were measured in both the standard and the natural and comfortable upright positions to assess whole-body balance.

Results

Significant differences were observed in the GCA (17.39 ± 6.90 vs. 10.90 ± 3.77, p < .001), GTA (25.63 ± 7.27 vs. 45.42 ± 8.15 p < .001), GLA (42.64 ± 8.05 vs. 20.21 ± 7.47 p < .001), CSVA-S (0.33 ± 2.76 cm vs. 8.54 ± 3.78 cm, p < 0.001), CSVA-H (1.53 ± 3.11 cm vs. 5.71 ± 3.26 cm, p < 0.001), CSVA-K (3.58 ± 2.47 cm vs. 5.22 ± 2.69 cm, p = 0.002) and CSVA-A (1.79 ± 1.92 cm vs. 4.79 ± 2.51 cm, p < 0.001) between the two different standing postures. Compared with the standard upright position, the natural and comfortable upright position results in a more kyphotic spine profile.

Conclusion

Significant differences in sagittal radiographic parameters were found between the standard upright position and the natural and comfortable upright position; the latter served as a marker for energy conservation during standing and revealed a more kyphotic spinal profile. The standard upright position and natural and comfortable upright position are equally important and should be addressed before a surgical plan is developed for patients who need surgery.

Association of Frailty and Self-Care Activity With Sagittal Spinopelvic Alignment in the Elderly

OBJECTIVE

To assess the relationship between frailty, activities of daily living (ADL), instrumental ADL (IADL), and sagittal spinopelvic parameters in the elderly.

METHODS

To compare the characteristics based on the FRAIL scale status (robust, prefrail, frail), continuous variables were analyzed using ANOVA with Tukey post hoc tests, and categorical variables were analyzed using χ² and Fisher's exact test. Multivariate linear regression was used to investigate cross-sectional association between sagittal alignment and FRAIL status.

RESULTS

Comparison analysis of the 3 groups (robust, prefrail, frail) demonstrated that frailty scale had significant correlations with T1 pelvic angle (T1PA, P = 0.019), pelvic tilt (PT, P = 0.004), pelvic incidence minus lumbar lordosis (PI-LL, P = 0.004) and ADL (P = 0.017). Multiple regression analysis that controlled for confounding factors confirmed the correlations between frailty scale and spinopelvic parameters (C7 sagittal vertical axis [SVA], B = 17.49, P = 0.028; T1PA, B = 4.83, P = 0.029; PT, B = 4.62, P = 0.003; PI-LL value, B = 7.11, P = 0.005). In addition, the ADL was associated with T1PA (B = 4.06, P = 0.006); whereas the IADL was correlated with C7 SVA (B = 11.38, P = 0.005), T1PA (B = 3.36, P = 0.003), and PI-LL (B = 3.13, P = 0.018).

CONCLUSIONS

Higher frailty score was associated with higher grades of sagittal spinopelvic malalignment and ADL in the elderly. Furthermore, higher ADL and IADL scores were associated with higher grades of sagittal spinopelvic malalignment. Frailty, ADL, IADL, and sagittal spinopelvic parameters were closely related to each other in the elderly.

Surgical Outcomes for Drop Body Syndrome in Adult Spinal Deformity

STUDY DESIGN

A multicenter retrospective case series of patients treated surgically for adult spinal deformity (ASD).

OBJECTIVE

The aim of this study was to compare clinical outcomes between propensity score matched ASD patients with or without drop body syndrome (DBS).

SUMMARY OF BACKGROUND DATA

DBS is an extreme primary sagittal-plane deformity often seen in Asian countries. Although the importance of sagittal alignment is widely recognized, surgical outcomes for deformities purely in the sagittal plane are poorly understood.

METHODS

This study included 243 consecutive patients (age 66 ± 17 years; range 22-78) who were treated surgically for ASD and were followed at least 2 years (mean follow-up 3.7 ± 2.3 years). DBS was defined as a primary lumbar kyphosis with PI-LL >40°, Cobb angle <30°, and multifidus cross-sectional area <300 mm. DBS patients were matched with non-DBS patients by propensity scores for age, gender, lowest instrumented vertebra (LIV) level, and number of levels fused. Demographics, radiographic findings, and clinical outcomes were compared between DBS and non-DBS patients.

RESULTS

Of 243 patients with ASD, 34 had DBS (14%); 28 of these were propensity-matched with ASD patients without DBS. Baseline bone mineral density (BMD), body mass index (BMI), and frailty were similar in DBS and non-DBS patients. Baseline sagittal alignment was worse in DBS than in non-DBS patients [C7SVA 14 ± 5 vs. 8 ± 5 cm; pelvic incidence (PI) - lumbar lordosis (LL) 60 ± 14 vs. 36 ± 20°], and scoliosis research society (SRS)22 scores were also worse for DBS patients (2.5 ± 0.6 vs. 2.9 ± 0.8). Although DBS patients had more complications (20 DBS vs. 16 non-DBS), the clinical outcomes were similarly improved in both groups after surgery. At the 2-year follow-up, the spinopelvic malalignment was worse in DBS than non-DBS patients (PI-LL 17 ± 16° vs. 8 ± 13°, P < 0.05).

CONCLUSION

DBS affected 14% of 234 ASD patients. Although DBS patients had inferior baseline SRS22 scores than non-DBS patients, ASD surgery resulted in similar clinical improvement in both groups. Future studies should examine the influence of lifestyle and genetics on clinical outcomes after surgery for DBS.

LEVEL OF EVIDENCE

3.

The effects of rotation on radiological parameters in the spine

BACKGROUND

Vertebral rotation in straight spines or in spines with small scoliosis may potentially affect measurement of radiological parameters in both the frontal and sagittal plane. This is important, since it could lead to potential misdiagnosis of scoliosis and other clinical consequences, and until now, this has not been examined.

PURPOSE

To examine the effect of axial vertebral rotation of the spine on measurement of common radiological parameters.

MATERIAL AND METHODS

Reconstructions from computed tomography scans of 40 consecutive included and anonymized patients with straight spines or small scoliosis. Fourteen sagittal and coronal reconstructions covering the whole pelvis and spine were executed. Radiographic parameters in both the frontal and sagittal plane were measured blinded and separately by three doctors. These parameters were evaluated for inter-rater reliability using intraclass correlation coefficient and mixed model analysis for the effects of rotation. The parameters were also analyzed sub-stratified according to "Lenke's classification" and 15 sub-categories of thoracic and lumbar Cobb's angle (CA).

RESULTS

Vertebral rotation in general does not have any significant effects in both the frontal and sagittal plane. However, there are significant effects on CA and spinopelvic radiologic parameters in extreme rotation or for larger scoliosis. Inter-rater reliability was very good to good.

CONCLUSION

In conclusion, axial spinal rotation does not influence common radiological parameters in the frontal and sagittal plane, except in cases of extreme rotation or large scoliosis for selected parameters; thus, this does not lead to potential misinterpretation in scoliosis diagnosis, treatment, or research.

Correlation between radiographic parameters and functional scores in degenerative lumbar and thoracolumbar scoliosis

INTRODUCTION

Adult scoliosis is a condition in which the spinal deformity occurs because of degeneration. Although various studies have agreed on the importance of restoring the sagittal balance, few have evaluated the relationship between functional scores and radiological parameters. The primary objective of this retrospective study was to demonstrate the correlation between radiographic parameters and functional outcomes in adult patients with lumbar or thoracolumbar degenerative scoliosis. The secondary objective was to assess the long-term effects of posterolateral fusion for treating this deformity.

STUDY OUTLINE

This single-centre retrospective study included 47 patients over 50years of age who had degenerative lumbar scoliosis treated with an instrumented posterolateral fusion; the mean follow-up was 6.4years (range 2 to 20).

METHODS

Radiographic analysis of A/P and lateral full spine standing radiographs was carried out with the KEOPS software. Three pelvic parameters (pelvic tilt, pelvic incidence, sacral slope), two spinal parameters (lumbar lordosis and thoracic kyphosis) and three sagittal balance parameters (C7 sagittal tilt, C7 Barrey's ratio and spinosacral angle) were calculated. The functional outcomes were evaluated through three self-assessment questionnaires: Oswestry Disability Index, SRS-30 and SF-36. The correlation between clinical and radiographic parameters was calculated with Spearman's correlation test.

RESULTS

There was a significant correlation between the SF-36 (PCS) and the following three sagittal parameters: sacral slope (r=-0.31453; P=0.04), lumbar lordosis (r=-0.30198; P=0.0491) and spinosacral angle (r=-0.311967; P=0.0366). The mean ODI score was 33.61, which corresponds to minimal to moderate disability. The mean physical (PCS) and mental (MCS) component summary scores of the SF-36 were 37.70 and 38.40, respectively. The mean SRS-30 score was 3.07.

CONCLUSION

It is essential that the sagittal balance be restored when treating degenerative lumbar scoliosis to generate better functional outcomes and better quality of life. To achieve this correction, instrumented posterolateral fusion appears to be a very reliable technique that leads to lasting improvement.

LEVEL OF EVIDENCE

IV.

Predictors of Health-Related Quality-of-Life After Complex Adult Spinal Deformity Surgery: A Scoli-RISK-1 Secondary Analysis

STUDY DESIGN

Longitudinal cohort.

OBJECTIVES

To identify variables that predict 2-year Short Form-36 Physical Composite Summary Score (SF-36PCS) and the Scoliosis Research Society-22R (SRS22-R) Total score after surgery for complex adult spinal deformity.

SUMMARY OF BACKGROUND DATA

Increasingly, treatment effectiveness is assessed by the extent to which the procedure improves a patient's health-related quality of life (HRQOL). This is especially true in patients with complex adult spinal deformity.

METHODS

The data set from the Scoli-Risk-1 study was queried for patients with complete 2-year SF-36 and SRS-22R. Regression analysis was performed to determine predictors of 2-year SF-36PCS and SRS-22R Total scores. Factors included were sex, age, smoking status, body mass index, American Society of Anesthesiologists (ASA) grade, Lower Extremity Motor Score improvement, indication for surgery, preoperative and 2-year maximum coronal Cobb angles, number of prior spine surgeries, number of three-column osteotomies, number of surgical levels, number of surgical stages, lowest instrumented level, presence and type of neurologic complication, and number of reported serious adverse events.

RESULTS

Of 272 cases enrolled, 206 (76%) cases were included in this analysis, 143 (69%) females, and mean age of 57.69 years. Factors that were significantly associated with of 2-year SF-36PCS were age (p < .001), ASA grade (p < .001), maximum preoperative Cobb angle (p = .007), number of three-column osteotomies (p = .049) and type of neurologic complication (p = .068). Factors predictive of 2-year SRS-22R Total scores were maximum preoperative Cobb angle (p = .001) and the number of serious adverse events (p = .071).

CONCLUSIONS

Factors predictive of lower 2-year HRQOLs after surgery for complex adult spinal deformity were older age, higher ASA grade, larger preoperative Cobb angle, larger numbers of three-column osteotomies, and the occurrence of both neurologic and nonneurologic complications. Most of these factors are beyond the control of surgeons. Still, surgeons should medically optimize a patient prior to surgery to minimize the risk of complications and offer the best chance of improving a patient's quality of life.

LEVEL OF EVIDENCE

Level II. Prospective cohort.

Preoperative and postoperative sagittal plane analysis in adult idiopathic scoliosis in patients older than 40 years of age

BACKGROUND CONTEXT

Most of the papers correlate sagittal radiographic parameters with health-related quality of life (HRQOL) scores for patients with scoliosis. However, we do not know how changes in sagittal profile influence clinical outcomes after surgery in adult population operated for mainly frontal deformity.

PURPOSE

This study aimed to analyze spinal sagittal profile in a population operated on adult idiopathic scoliosis (AS) and to describe variations in sagittal parameters after surgery and the association between those variations and clinical outcomes.

DESIGN/SETTING

This is a historical cohort study.

PATIENT SAMPLE

We included in this study 40 patients operated on AS, older than 40 at the time of surgery (mean age 54.9), and with more than 2-year follow-up (mean 7.4 years).

OUTCOME MEASURES

Full-length free-standing radiographs, Scoliosis Research Society 22 (SRS22) and Short Form 36 (SF36) instruments, and satisfaction with outcomes were available at final follow-up.

METHODS

Sagittal preoperative and final follow-up radiographic parameters, radiographic correlation with HRQOL scores at final follow-up, and association between satisfaction and changes in sagittal profile were analyzed. A multivariate analysis was performed. No funds were received for this article.

RESULTS

Preoperatively, the spinal sagittal plane tended to exhibit kyphosis. Most sagittal parameters did not improve at final follow-up with respect to preoperative values. We saw, after univariate analysis, that worse sagittal profile leads to worse HRQOL, but after multivariate analysis, only spinal tilt (ST) persisted as possible predictor for worse SRS activity scores. Frontal Cobb significantly improved. Most patients (82%) were satisfied with final outcomes. Variations in sagittal profile parameters did not differ between satisfied and dissatisfied patients.

CONCLUSIONS

Although most sagittal plane parameters did not improve after surgery, surgical treatment in AS achieves a high satisfaction rate. Good clinical results do not correlate with improving sagittal plane parameters. Sagittal profile measurements are not helpful to decide surgical treatment in patients with mainly frontal deformity.

Sagittal spino-pelvic adjustment in severe Lenke 1 hypokyphotic adolescent idiopathic scoliosis patients

PURPOSE

The human standing position requires permanent reciprocal spino-pelvic adjustments to obtain a dynamic and economic posture. This study focuses on a hypokyphotic Lenke 1 adolescent idiopathic scoliosis (AIS) patients cohort and points out their particular lumbo-pelvic adaptive mechanisms to maintain a neutral sagittal balance.

METHODS

Preoperative retrospective analysis of prospectively collected data on a monocentric cohort of 455 AIS patients planned for corrective surgery. Radiological low-dose system coupled with a validated clinical routine software allowed to obtain data from eighty-four hypokyphotic [thoracic kyphosis (TK) <20°] Lenke 1 patients and were separately analyzed. Bilateral Student and one-way ANOVAs were conducted for statistical analysis.

RESULTS

Mean Cobb angle was 46.3° (±7.2), TK was 11° (±7.1), sagittal vertical axis (SVA) was -10.1 mm (±30.9), pelvic incidence (PI) was 55.7° (±12.9). Fifty percents of patients were posteriorly imbalanced. Among them, patients with a low PI used an anteversion of their pelvis [indicated by a high pelvic tilt (PT) angle] but were not able to increase their lumbar lordosis (LL) to minimize the posterior spinal shift.

CONCLUSIONS

Hypokyphotic Lenke 1 AIS patients use lumbo-pelvic compensatory mechanisms to maintain their global balance with a poor effectiveness. Subjects with a low PI have a restricted range of LL adaptation. Attention should be paid during surgical planning not to overcorrect lordosis in the instrumented levels in case of non-selective fusion, that may induce posterior shift of the fusion mass and expose to junctional syndromes and poor functional outcomes in this particular patients.

A Comprehensive Analysis of the SRS-Schwab Adult Spinal Deformity Classification and Confounding Variables: A Prospective, Non-US Cross-sectional Study in 292 Patients

STUDY DESIGN

Cross-sectional analyses on a consecutive, prospective cohort.

OBJECTIVE

To evaluate the ability of the Scoliosis Research Society (SRS)-Schwab Adult Spinal Deformity Classification to group patients by widely used health-related quality-of-life (HRQOL) scores and examine possible confounding variables.

SUMMARY OF BACKGROUND DATA

The SRS-Schwab Adult Spinal Deformity Classification includes sagittal modifiers considered important for HRQOL and the clinical impact of the classification has been validated in patients from the International Spine Study Group database; however, equivocal results were reported for the Pelvic Tilt modifier and potential confounding variables were not evaluated.

METHODS

Between March 2013 and May 2014, all adult spinal deformity patients from our outpatient clinic with sufficient radiographs were prospectively enrolled. Analyses of HRQOL variance and post hoc analyses were performed for each SRS-Schwab modifier. Age, history of spine surgery, and aetiology of spinal deformity were considered potential confounders and their influence on the association between SRS-Schwab modifiers and aggregated Oswestry Disability Index (ODI) scores was evaluated with multivariate proportional odds regressions. P values were adjusted for multiple testing.

RESULTS

Two hundred ninety-two of 460 eligible patients were included for analyses. The SRS-Schwab Classification significantly discriminated HRQOL scores between normal and abnormal sagittal modifier classifications. Individual grade comparisons showed equivocal results; however, Pelvic Tilt grade + versus +  + did not discriminate patients according to any HRQOL score. All modifiers showed significant proportional odds for worse aggregated ODI scores with increasing grade levels and the effects were robust to confounding. However, age group and aetiology had individual significant effects.

CONCLUSION

The SRS-Schwab sagittal modifiers reliably grouped patients graded 0 versus + / +  + according to the most widely used HRQOL scores and the effects of increasing grade level on odds for worse ODI scores remained significant after adjusting for potential confounders. However, effects of age group and aetiology should not be neglected.

LEVEL OF EVIDENCE

3.

Prediction of health status based on postoperative radiographic variables in adult scoliosis

OBJECTIVE

To evaluate the effect of surgical treatment on health related quality of life (HRQOL) and radiographic variables in patients with adult scoliosis.

METHODS

Sixty-eight patients with adult spinal deformities underwent radiographic analysis. The enrollment criteria were as follows: age older than 18 years, adult degenerative or progressive idiopathic scoliosis (Cobb angle >10°), and surgical treatment within one year before this study was undertaken. The following variables were measured: curve type, apical level, curve magnitude, coronal and sagittal balance using a C7 plumb line (C7 PL) and gravity line, lateral intervertebral olisthesis, lumbar lordosis, sacral slope and pelvic tilt. HRQOL was assessed by the Oswestry Disability Index (ODI). Both preoperative and postoperative data were collected and changes in radiographically assessed variables and ODI scores attributable to surgery calculated; correlations between these changes were then assessed. The radiographically assessed variables and ODI scores were analyzed with SigmaStat (SPSS, Chicago, IL, USA). The level of statistical significance was set at P < 0.05.

RESULTS

Surgical treatment resulted in improvements in ODI scores and several radiographically assessed variables, including sagittal balance, lumbar lordosis, lateral olisthesis and coronal Cobb angle. Only sagittal balance expressed as C7 PL was correlated to both preoperative and postoperative ODI. Gravity line, an alternative measurement of spinal balance, did not provide better correlations with HRQOL than C7 PL.

CONCLUSIONS

Spinal balance assessed by gravity line did not provide a better correlation with HRQOL than C7 PL. Loss of sacral slope and retroverted pelvis are commonly seen in adult scoliosis and are not significantly changed by surgical treatment, including restoration of lumbar lordosis and sagittal balance.

Individual and contextual characteristics as determinants of sagittal standing posture: a population-based study of adults

BACKGROUND CONTEXT

Sagittal standing posture is associated with musculoskeletal symptoms and quality of life. However, the frequency and determinants of suboptimal sagittal alignment outside the clinical context remain to be clarified.

PURPOSE

To estimate the association of sociodemographic, anthropometric, and behavioral characteristics with sagittal standing posture among adults from the general population.

STUDY DESIGN

Cross-sectional evaluation of a population-based sample.

PATIENT SAMPLE

As part of the EPIPorto study, 489 adults were assessed during 2005 to 2008.

OUTCOME MEASURES

Individual spinopelvic parameters were measured. Additionally, participants were classified into one of four types of sagittal postural patterns (Roussouly classification: Types 1, 2, and 4 corresponding to nonneutral postures and Type 3 to a neutral posture).

METHODS

Spinopelvic parameters were recorded from 36-inch sagittal radiographs obtained in free-standing posture. Age, sex, education, occupation, body mass index (BMI), waist circumference, total physical activity, leisure time physical activity, time spent in sitting position, smoking status, and tobacco cumulative exposure were collected. Individual parameters and patterns of sagittal posture were compared across categories of participants' characteristics.

RESULTS

Older age, lower educational level, blue collar occupation, and overall and central obesity were associated with increased sagittal vertical axis and pelvic tilt/pelvic incidence ratio. Taking the neutral postural pattern (Type 3) as reference for the outcome in a multinomial regression model, independently of age, sex, education, total physical activity, and smoking status, overweight adults had higher odds of Type 2 (odds ratio [OR]=1.92; 95% confidence interval [CI]: 1.13-3.27) and Type 4 (OR=2.13; 95% CI: 1.16-3.91) postural patterns in comparison with normal weight subjects. Overall and central obesity were positively related with Type 1 postural pattern (OR=6.10, 95% CI: 1.52-24.57 and OR=3.54, 95% CI: 1.13-11.11, respectively). There was also a weak direct association between female sex and Type 1 postural pattern. Regarding behavioral factors, subjects with total physical activity above the first third exhibited all nonneutral postural patterns less frequently, and current smokers were more likely to present a Type 4 postural pattern.

CONCLUSIONS

Higher BMI and central obesity were important potential determinants of nonneutral posture among adults from the general population. Future research should investigate the potential effectiveness of overweight prevention and management in avoiding sagittal misalignment conditions.

Sagittal standing posture, back pain, and quality of life among adults from the general population: a sex-specific association

STUDY DESIGN

A prospective radiographical study of sagittal standing posture among adults consecutively recruited from the general population.

OBJECTIVE

To analyze the relation of suboptimal sagittal standing posture with back pain and health-related quality of life in general adult males and females.

SUMMARY OF BACKGROUND DATA

Clinical studies have shown the association of sagittal standing posture with pain and reduced quality of life, but this relation has not been assessed in the general adult population.

METHODS

As part of the EPIPorto population-based study of adults, 178 males and 311 females were evaluated. Age, education, and body mass index were recorded. Radiographical data collection consisted of 36-in. standing sagittal radiographs. Creation of 3 groups for individual spinopelvic parameters was performed (low, intermediate, or high), and 1 of 4 sagittal types of postural patterns attributed to each participant (Roussouly classification). Back pain prevalence and severity were assessed on the basis of self-reported data and health-related quality of life using 2 main components of the 36-Item Short Form Health Survey.

RESULTS

In males, differences in back pain severity were observed only among pelvic tilt/pelvic incidence ratio groups. Females presenting high pelvic incidence and sacral slope exhibited higher odds of severe back pain than those with intermediate values (adjusted odds ratios = 2.21 and 2.15; 95% confidence interval, 1.24-3.97 and 1.21-3.86; respectively). Sagittal vertical axis showed the largest differences in physical quality of life of females: high group had 8.8 lower score than the low group (P < 0.001), but this result lost statistical significance after adjustment for age, education, and body mass index.

CONCLUSION

Sagittal standing posture was not consistently associated with quality of life measures in males. Increased pelvic incidence and sacral slope may be involved in causing severe back pain among females. Monitoring sagittal postural parameters has limited usefulness as a screening tool for causes of unspecific musculoskeletal symptoms in the general adult population.

LEVEL OF EVIDENCE

3.

Radiographic Outcomes of Adult Spinal Deformity Correction: A Critical Analysis of Variability and Failures Across Deformity Patterns

STUDY DESIGN

Multicenter, prospective, consecutive, surgical case series from the International Spine Study Group.

OBJECTIVES

To evaluate the effectiveness of surgical treatment in restoring spinopelvic (SP) alignment.

SUMMARY OF BACKGROUND DATA

Pain and disability in the setting of adult spinal deformity have been correlated with global coronal alignment (GCA), sagittal vertical axis (SVA), pelvic incidence/lumbar lordosis mismatch (PI-LL), and pelvic tilt (PT). One of the main goals of surgery for adult spinal deformity is to correct these parameters to restore harmonious SP alignment.

METHODS

Inclusion criteria were operative patients (age greater than 18 years) with baseline (BL) and 1-year full-length X-rays. Thoracic and thoracolumbar Cobb angle and previous mentioned parameters were calculated. Each parameter at BL and 1 year was categorized as either pathological or normal. Pathologic limits were: Cobb greater than 30°, GCA greater than 40 mm, SVA greater than 40 mm, PI-LL greater than 10°, and PT greater than 20°. According to thresholds, corrected or worsened alignment groups of patients were identified and overall radiographic effectiveness of procedure was evaluated by combining the results from the coronal and sagittal planes.

RESULTS

A total of 161 patients (age, 55 ± 15 years) were included. At BL, 80% of patients had a Cobb angle greater than 30°, 25% had a GCA greater than 40 mm, and 42% to 58% had a pathological sagittal parameter of PI-LL, SVA, and/or PT. Sagittal deformity was corrected in about 50% of cases for patients with pathological SVA or PI-LL, whereas PT was most commonly worsened (24%) and least often corrected (24%). Only 23% of patients experienced complete radiographic correction of the deformity.

CONCLUSIONS

The frequency of inadequate SP correction was high. Pelvic tilt was the parameter least likely to be well corrected. The high rate of SP alignment failure emphasizes the need for better preoperative planning and intraoperative imaging.

Sagittal balance, a useful tool for neurosurgeons?

New instrumentation techniques have made any correction of the spinal architecture possible. Sagittal balance has been described as an important parameter for assessing spinal deformity in the early 1970s, but over the last decade its importance has grown with the published results in terms of overall quality of life and fusion rate. Up until now, most of the studies have concentrated on spinal deformity surgery, but its use in the daily neurosurgery practice remains uncertain and may warrant further studies.

[Relationship between clinical results and sagittal profile in adult scoliosis. Value of the spinal-sacral angle and the spinal inclination angle]

OBJECTIVES

To assess the clinical validity of two new recently described parameters (spinal-sacral angle (SSA) and spinal inclination angle (SIA) in adult scoliosis (AS) for evaluating the spinal-pelvic sagittal profile, as well as their still undefined role in AS.

MATERIAL AND METHOD

A non-concurrent prospective radiographic and clinical study was conducted on 59 primary surgeries of AS (Cobb>40°), with a minimum of 2 years follow-up. The available X-rays and health questionnaires of 49 patients were used in the study. The changes in X-ray parameters after surgery were evaluated (Wilcoxon test), as well as the correlations as regards the clinical-radiography-age parameters (Spearman test and multiple linear regression).

RESULTS

The median post-surgical follow-up was 8.5 years, and the median age of the patients was 49.5 years. There was a statistically significant change with the surgery in the SSA and SIA (less than 5° in both), thoracic kyphosis, lumbar lordosis (LL), pelvic rotation, sagittal balance (SB) and frontal Cobb. There was no correlation between pain and SSA-ST. There was a significant relationship between activity and SSA, ST, LL, SB, and age. After the multivariate analysis only age (not SSA or SIA) remained as a possible predictor of lower activity.

DISCUSSION

When frontal deformity predominates, the sagittal radiographic parameters, including the newest angles, although they have an influence patient activity when analysed individually, they lose this influence when they are analysed together and with other clinical parameters.

CONCLUSIONS

The SSA and SIA hardly change with surgery. They only correlate with activity, but cannot be considered predictors of this. Thus they do seem to be useful measurements in AS.

Comparative analysis of surgical approaches and osteotomies for the correction of sagittal plane spinal deformity in adults

STUDY DESIGN

A retrospective review.

OBJECTIVE

To compare the radiographical and clinical profiles between 2 surgical approaches for the correction of sagittal plane spinal deformity.

SUMMARY OF BACKGROUND DATA

Sagittal plane decompensation is the radiographical parameter that carries the greatest impact on adverse outcomes. Surgical correction methods are heterogeneous, and opposing views pervade the spine community in consideration of the most effective approach and techniques to achieve correction.

METHODS

A total of 33 cases with sagittal spinal deformity were assessed according to their surgical approach, posterior only versus combined anteroposterior group. Comparison was based on the demographic data, and radiographical parameters included pelvic tilt, pelvic incidence, sacral slope, lumbar lordosis, thoracic kyphosis, and sagittal vertical axis.

RESULTS

Twenty two subjects were identified for the posterior-only and 11 subjects for the anteroposterior group. Average age was 58.7 years in the posterior-only and 55.7 years for the combined approach. Preoperative mean sagittal vertical axis was 186.6 and 147.7 mm, for the posterior-only and combined approaches, respectively (P = 0.1). Preoperative mean pelvic tilt was 34.2° for the posterior-only and 36.9° for the combined approach group (P = 0.5). A greater operative time for the combined approach was significant, 535 versus 333 minutes for the posterior-only approach (P < 0.001). In the posterior-only group, 8 of 22 patients and 7 of 11 patients in the combined-approach cohort experienced a postoperative complication (P = 0.16). The average follow-up was 41.8 and 47.7 months for the posterior-only and combined approaches, respectively (P = 0.4).

CONCLUSION

A posterior-only or combined surgical approach had comparable radiographical outcomes. Higher morbidity was significant in regard to operative time in the combined-approach group. Deciding on the approach best suited for achieving correction in the sagittal plane likely resides on the surgeon's experience and expertise.