Rigorous Correction of Sagittal Vertical Axis Is Correlated With Better ODI Outcomes After Extensive Corrective Fusion in Elderly or Extremely Elderly Patients With Spinal Deformity

Factors Influencing Maintenance of Alignment and Functional Improvement Following Adult Spinal Deformity Surgery: A 3-Year Outcome Analysis

STUDY DESIGN

This was a retrospective review.

OBJECTIVE

To assess the factors contributing to durability of surgical results following adult spinal deformity (ASD) surgery.

SUMMARY OF BACKGROUND

Factors contributing to the long-term sustainability of ASD correction are currently undefined.

MATERIALS AND METHODS

Operative ASD patients with preoperatively (baseline) and 3-year postoperatively radiographic/health-related quality of life data were included. At 1 and 3 years postoperatively, a favorable outcome was defined as meeting at least three of four criteria: (1) no proximal junctional failure or mechanical failure with reoperation, (2) best clinical outcome (BCO) for Scoliosis Research Society (SRS) (≥4.5) or Oswestry Disability Index (ODI) (<15), (3) improving in at least one SRS-Schwab modifier, and (4) not worsening in any SRS-Schwab modifier. A robust surgical result was defined as having a favorable outcome at both 1 and 3 years. Predictors of robust outcomes were identified using multivariable regression analysis with conditional inference tree for continuous variables.

RESULTS

We included 157 ASD patients in this analysis. At 1 year postoperatively, 62 patients (39.5%) met the BCO definition for ODI and 33 (21.0%) met the BCO for SRS. At 3 years, 58 patients (36.9%) had BCO for ODI and 29 (18.5%) for SRS. Ninety-five patients (60.5%) were identified as having a favorable outcome at 1 year postoperatively. At 3 years, 85 patients (54.1%) had a favorable outcome. Seventy-eight patients (49.7%) met criteria for a durable surgical result. Multivariable adjusted analysis identified the following independent predictors of surgical durability: surgical invasiveness >65, being fused to S1/pelvis, baseline to 6-week pelvic incidence and lumbar lordosis difference >13.9°, and having a proportional Global Alignment and Proportion score at 6 weeks.

CONCLUSIONS

Nearly 50% of the ASD cohort demonstrated good surgical durability, with favorable radiographic alignment and functional status maintained up to 3 years. Surgical durability was more likely in patients whose reconstruction was fused to the pelvis and addressed lumbopelvic mismatch with adequate surgical invasiveness to achieve full alignment correction.

Introduction of a New Radiographic Parameter to Predict Proximal Junctional Kyphosis in Adult Spinal Deformity: UIVPTA (Uppermost Instrumented Vertebra-Pelvic Tilt Angle)

OBJECTIVE

To introduce a new sagittal parameter, uppermost instrumented vertebra-pelvic tilt angle (UIVPTA), and to determine the effects on the proximal junctional kyphosis (PJK) development in adult spinal deformity (ASD) surgery.

METHODS

Patients ≥ 60 years with ASD who underwent low thoracic spine to pelvis fusion with a minimum of 2-years of follow-up were included in this study. Two groups were created according to PJK development. Various clinical and radiographic factors were compared between PJK and non-PJK groups to identify the risk factors for PJK. Cutoff value of UIVPTA for PJK development was calculated using receiver operating characteristic curve according to different pelvic incidence groups. Linear regression analysis was performed to identify factors to affect UIVPTA.

RESULTS

One hundred fifity-one patients were included in this study. There were 135 female patients (89.4%). Mean age was 70.5 years. PJK developed in 65 patients (43.0%). Multivariate analysis showed that overcorrection relative to age-adjusted pelvic incidence (PI) minus lumbar lordosis (LL) (PI-LL) target and lower UIVPTA were independent risk factors for PJK. The cutoff value of UIVPTA for PJK development was calculated as 4.0° in patients with PI less than 45°, 9.5° in patients with PI between 45° and 60°, and 13.0° in patients with PI greater than 60°. Linear regression analysis showed that UIVPTA was positively affected by postoperative values of LL (coefficient = 0.505), PI-LL (coefficient = 0.674), and pelvic tilt (coefficient = 0.286).

CONCLUSION

Optimal correction within the age-adjusted PI-LL combined with keeping UIVPTA within optimal range is suggested for the prevention of PJK.

Validation of Age-adjusted Ideal Sagittal Alignment in Terms of Proximal Junctional Failure and Clinical Outcomes in Adult Spinal Deformity

STUDY DESIGN

Retrospective study.

OBJECTIVE

To validate the age-adjusted ideal sagittal alignment in terms of proximal junctional failure (PJF) and clinical outcomes.

SUMMARY OF BACKGROUND

It is reported that optimal sagittal correction with regard to the age-adjusted ideal sagittal alignment reduces the risk of PJF development. However, few studies have validated this concept. The age-considered optimal correction is likely to be undercorrection in terms of conventional surgical target, such as pelvic incidence (PI)-lumbar lordosis (LL) within ±9°. Therefore, the clinical impact of age-adjusted sagittal alignment should be evaluated along with radiographic effect.

MATERIALS AND METHODS

Adult spinal deformity patients, aged 50 years and above, who underwent greater than or equal to four-level fusion to sacrum with a minimum of four years of follow-up data were included in this study. Radiographic risk factors for PJF (including age-adjusted ideal PI-LL) were evaluated with multivariate analyses. Three groups were created based on PI-LL offset between age-adjusted ideal PI-LL and actual actual PI-LL: undercorrection, ideal correction, and overcorrection. Clinical outcomes were compared among the three groups.

RESULTS

This study included 194 adult spinal deformity patients. The mean age was 68.5 years and there were 172 females (88.7%). PJF developed in 99 patients (51.0%) at a mean postoperative period of 14.9 months. Multivariate analysis for PJF revealed that only PI-LL offset group had statistical significance. The proportion of patients with PJF was greatest in the overcorrection group followed by the ideal correction and undercorrection groups. Overcorrected patients regard to the age-adjusted ideal alignment showed poorer clinical outcomes than the other patient groups.

CONCLUSIONS

Overcorrection relative to age-adjusted sagittal alignment increases the risk of PJF development and is associated with poor clinical outcomes. Older patients and those with small PI are likely to be overcorrected in terms of the age-adjusted PI-LL target. Therefore, the age-adjusted alignment should be considered more strictly in these patients.

The validation study of preoperative surgical planning for corrective target in adult spinal deformity surgery with 5-year follow-up for mechanical complications

PURPOSE

We used the Hamamatsu formula as an indicator of correction goals in surgery for adult spinal deformity (ASD). However, it is reported that correction according to Global Alignment and Proportion (GAP) score and the Roussouly algorithm reduces implant-related complications. The purpose of this study was to validate three preoperative plannings for the incidence of complications.

METHODS

Patients who underwent ASD surgery and followed up for 5 years were included. The Hamamatsu formula was also divided into three groups: ideal (I), moderate (M), and under (U). The GAP score was divided into three groups: proportioned (P), moderately disproportioned (MD), and severely disproportioned (SD). Patients who met the postoperative Roussouly classification algorithm were defined as the restored (R) group and those who did not were defined as the non-restored (NR) group. Proximal junctional kyphosis (PJK) and rod fractures were investigated.

RESULTS

In the Hamamatsu formula, there were 51, 108, and 44 patients in Groups I, M, and U, respectively, with no significant differences in their complications. In the GAP score, there were 45, 71, and 87 patients in the P, MD, and SD group, respectively, with no significant differences in their complications. In the Roussouly classification, there were 102 and 101 patients in the R and NR group, respectively, with a significant difference in their complication rate (R/NR = 51%:70%; P = 0.005). PJK was significantly lower in the R group (R/NR = 15%:30%; P = 0.010).

CONCLUSION

Correction according to the Roussouly algorithm is useful for the prevention of mechanical complications, especially PJK.

Age and Gender Based Spinopelvic and Regional Spinal Alignment in Asymptomatic Adult Volunteers: Results of the Multi-Ethnic Alignment Normative Study (MEANS)

BACKGROUND

Spinal alignment can have a significant impact on a patient's overall quality of life. Predicting the ideal sagittal spinal alignment of a specific individual is still a difficult task. The Multi-Ethnic Alignment Normative Study (MEANS) investigated skeletal alignment, including the spine and lower extremities, of the largest multi-ethnic cohort of asymptomatic adult volunteers. In this analysis, the authors aim to assess normative values of spinopelvic parameters and the regional cervical, thoracic, and lumbar spinal alignment in asymptomatic volunteers stratified by age and sex.

MATERIALS AND METHODS

Asymptomatic volunteers between ages 18 and 80 years were enrolled prospectively from centers in France, Japan, Singapore, Tunisia, and the United States. Volunteers included reported no significant neck or back pain (Visual Analog Scale ≤2), nor any known spinal disorder(s). All volunteers underwent a standing full-body or full-spine low-dose stereoradiograph.

RESULTS

MEANS consisted of 468 volunteers with a mean age of 40.4±14.8 years. Mean cervical lordosis from C2 to C7 was -0.4±12.7°. The T1-slope averaged 23.0±7.9° and showed strong correlation ( r =0.87) with the C7-slope mean of 19.8±8.6°. Thoracic kyphosis (TK) from T4 to T12 showed a mean of 37.4±10.9°. Average L1-S1 lumbar lordosis (LL) was -57.4±11.3°. The mean pelvic incidence (PI) measured 52.0±10.7° and pelvic tilt was 12.5±7.3°. Sacral slope averaged 39.5±8.2°. The average PI-LL was -5.4±10.7°. Approximately 60% of volunteers met the PI-LL criteria within ±10°, 8.3% were ≥10°, while 32.1% were ≤-10°. LL showed moderate correlation with PI ( r =0.53) and TK ( r =0.50), while there was no correlation between TK and PI. Multiple linear regression including PI, TK, and age resulted in the following equation LL=14.6+0.57 (PI)+0.57 (TK)-0.2 (age) ( r =0.75).

CONCLUSIONS

LL did not change with increasing age in asymptomatic volunteers. However, TK did increase with age leading to an increase in T1-slope and a compensatory increase in cervical lordosis. TK did not correlate with PI and was an independent variable in the prediction of LL.

LEVEL OF EVIDENCE

Level II-prospective cohort study.

Compensatory biomechanics and spinal loading during dynamic maneuvers in patients with chronic low back pain

Purpose

This study explores the biomechanics underlying the sit-to-stand (STS) functional maneuver in chronic LBP patients to understand how different spinal disorders and levels of pain severity relate to unique compensatory biomechanical behaviors. This work stands to further our understanding of the relationship between spinal loading and symptoms in LBP patients.

Methods

We collected in-clinic motion data from 44 non-specific LBP (NS-LBP) and 42 spinal deformity LBP (SD-LBP) patients during routine clinical visits. An RGB-depth camera tracked 3D joint positions from the frontal view during unassisted, repeated STS maneuvers. Patient-reported outcomes (PROs) for back pain (VAS) and low back disability (ODI) were collected during the same clinical visit.

Results

Between patient groups, SD-LBP patients had 14.3% greater dynamic sagittal vertical alignment (dSVA) and 10.1% greater peak spine torque compared to NS-LBP patients (p < 0.001). SD-LBP patients also had 11.8% greater hip torque (p < 0.001) and 86.7% greater knee torque (p = 0.04) compared to NS-LBP patients. There were no significant differences between patient groups in regard to anterior or vertical torso velocities, but anterior and vertical torso velocities correlated with both VAS (r = − 0.38, p < 0.001) and ODI (r = − 0.29, p = 0.01). PROs did not correlate with other variables.

Conclusion

Patients with LBP differ in movement biomechanics during an STS transfer as severity of symptoms may relate to different compensatory strategies that affect spinal loading. Further research aims to establish relationships between movement and PROs and to inform targeted rehabilitation approaches.

Effect of overcorrection on proximal junctional kyphosis in adult spinal deformity: analysis by age-adjusted ideal sagittal alignment

BACKGROUND CONTEXT

The effect of the degree of lumbar lordosis (LL) correction on proximal junctional kyphosis (PJK) has not been analyzed in context of the age-adjusted sagittal alignment goal.

PURPOSE

To determine the effect of sagittal correction on the incidence of PJK after an age-adjusted analysis in patients with adult spinal deformity (ASD).

STUDY DESIGN/SETTING

Retrospective comparative study.

PATIENT SAMPLE

Seventy-eight ASD patients who underwent deformity correction.

OUTCOME MEASURES

Visual analog scale (VAS), Oswestry Disability Index (ODI), and imaging.

METHODS

This study included 78 ASD patients who underwent deformity correction and were followed-up more than 2 years. Patients were grouped according to the degree of LL correction relative to pelvic incidence (PI) by adjusting for age using the following formula: (age-adjusted ideal PI - LL) - (postoperative PI - LL). These were group U (undercorrection; <-10˚, N=15), group I (ideal correction; -10˚-10˚, N=34), and group O (over correction, >10˚, N=29). Various clinical and radiological parameters were compared among groups. The risk factors for PJK were also evaluated.

RESULTS

The overall incidence of PJK was 32.1% (25/78), with significantly higher PJK rate in group O (48.3%) compared with groups U (13.3%) and I (26.5%) (p=.041). The degree of postoperative LL correction relative to the PI by adjusting for age was a risk factor for the development of PJK (11.4° for PJK vs. 0.2° for non-PJK, p=.033). In addition, 2-year postoperative VAS (7.0 vs. 3.4, p<.001) and ODI (28.9 vs. 24.8, p=.040) scores were significantly higher in the PJK group than in the non-PJK group. A small PI (PI < 45°) was associated with a tendency of overcorrection (73.3%, P < 0.001) and thereby with the high incidence of PJK (53.3%, p=.005).

CONCLUSIONS

Overcorrection of LL relative to PI considering age-adjusted ideal sagittal alignment tends to increase the incidence of PJK. The incidence of PJK is expected to be high in patients with low PI (<45°) because of the tendency of overcorrection. To reduce the risk of PJK, surgeons should take age-adjusted parameters into account and exercise caution not to overcorrect patients with low PI, since this can result in suboptimal clinical outcomes.

Perioperative Predictive Factors for Positive Outcomes in Spine Fusion for Adult Deformity Correction

Purpose: Identifying perioperative factors that may influence the outcomes of long spine fusion for the treatment of adult deformity is key for tailored surgical planning and targeted informed consent. The aim of this study was to analyze the association between demographic or perioperative factors and clinical outcomes 2 years after long spine fusion for the treatment of adult deformity. Methods: This study is a multivariate analysis of retrospectively collected data. All patients who underwent long fusion of the lumbar spine for adult spinal deformity (January 2016–June 2019) were included. The outcomes of interest were the Oswestry disability index (ODI), visual analogic scale (VAS) preoperatively and at 1 and 2 years’ follow up, age, body mass index, American Society of Anaesthesiologists (ASA) score, upper and lowest instrumented vertebrae (UIV and LIV, respectively), length of surgery, estimated blood loss, and length of hospital stay. Results: Data from 192 patients were available. The ODI at 2 years correlated weakly to moderately with age (r = 0.4), BMI (r = 0.2), ASA (r = 0.3), and LIV (r = 0.2), and strongly with preoperative ODI (r = 0.6). The leg VAS at 2 years moderately correlated with age (r = 0.3) and BMI (r = 0.3). Conclusion: ODI and VAS at 2 years’ follow-up had no to little association to preoperative age, health status, LIV, or other peroperative data, but showed a strong correlation with preoperative ODI and pain level.

Importance of achieving Scoliosis Research Society-22r minimal clinically important difference for improving patient satisfaction after adult spinal deformity surgery

OBJECTIVE

Achievement of minimal clinically important differences (MCIDs) in the Scoliosis Research Society-22r (SRS-22r) subdomains represents surgical efficacy. However, whether achievements of MCIDs in SRS-22r domains are associated with long-term satisfaction in patients with adult spinal deformity (ASD) is unclear. This study aimed to elucidate factors affecting patient satisfaction after thoracopelvic corrective fusion surgery in patients with ASD.

METHODS

Data obtained in 187 patients with ASD who underwent extensive corrective fusion surgery from the thoracic spine to the pelvis between 2010 and 2017 and underwent follow-up for 2 years were retrospectively reviewed. The authors investigated the likelihood of achieving MCIDs in the function, pain, self-image, mental health, and subtotal domains 2 years after surgery. The following MCID values were used: function, 0.90; pain, 0.85; self-image, 1.05; mental health, 0.70; and subtotal, 1.05. Multivariate analysis was performed to evaluate factors associated with patient satisfaction 2 years after surgery.

RESULTS

The average satisfaction scores in the group that achieved MCID and the group that did not were as follows: 3.97 and 3.37 for function (p < 0.001), 3.66 and 3.51 for pain (p = 0.221), 3.84 and 3.06 for self-image (p < 0.001), 3.82 and 3.28 for mental health (p < 0.001), and 3.96 and 3.30 for subtotal (p < 0.001), respectively. Except for the pain domain, the group that achieved MCIDs showed greater satisfaction than the group that did not achieve MCIDs. On multivariate analysis, factors related to postoperative satisfaction were achievement of SRS-22r self-image (standardization coefficient 0.322, p < 0.001) and function (standardization coefficient 0.179, p = 0.026) MCIDs. Perioperative complications and revision surgery were not related to patient satisfaction.

CONCLUSIONS

Multivariate analysis demonstrated that achievement of MCIDs in SRS-22r self-image and function domains was significantly associated with postoperative satisfaction. Given that patients with poor preoperative health-related quality of life are more likely to achieve MCIDs in SRS-22r domains, surgeons should carefully consider whether to operate on patients with relatively good baseline health-related quality of life when making surgical decisions.

Improvements in physical functionality in elderly patients with spinal deformity after corrective fusion surgery: a gait analysis

OBJECTIVE

Extensive corrective fusion surgery was performed on elderly patients with adult spinal deformity (ASD) to improve abnormal posture. Varying improvements in postoperative walking function were expected owing to differences in muscular strength and bone quality between patients in their 40s and those over 75 years of age. The purpose of this study was to compare preoperative and postoperative gait posture and physical functionality in elderly patients with ASD who underwent extensive corrective fusion to the thoracic spine.

METHODS

A prospectively maintained surgical database was reviewed for patients with ASD who underwent corrective fusion surgery (thoracic spine to pelvis) between 2011 and 2016. The cohort was divided into three age groups: nonelderly (40-64 years), young-old (65-74 years), and old-old (> 75 years). Patients underwent a 4-m walk test preoperatively and 2 years postoperatively to measure gait-trunk tilt angle and walking speed (meters per minute).

RESULTS

Among 291 patients with ASD who underwent corrective fusion surgery, 56 patients (14 men and 42 women; mean age 68.8 years) were included. Mean preoperative gait-trunk tilt angle (12.9° vs 5.2°, p < 0.01) and walking speed (41.2 m/min vs 45.7 m/min, p < 0.01) significantly improved postoperatively. Intergroup analysis revealed that the mean preoperative gait-trunk tilt angles in the nonelderly (n = 13), young-old (n = 28), and old-old (n = 15) groups were 11.9°, 10.0°, and 19.3°, respectively; postoperatively, these improved to 4.5°, 4.5°, and 7.2°, respectively. Mean preoperative walking speeds of 47.9, 40.0, and 37.7 m/min improved to 52.4, 44.8, and 41.5 m/min postoperatively in the nonelderly, young-old, and old-old groups, respectively. There were no statistically significant differences in degree of improvement in gait-trunk tilt angle and walking speed among groups.

CONCLUSIONS

Extensive corrective fusion surgery improved the postoperative walking posture of patients with ASD. Statistical analysis of gait measurements demonstrated intergroup equivalence, indicating comparable improvement in physical functionality in elderly and middle-aged patients after corrective fusion surgery.

Major Trauma in Elderly Patients: Worse Mortality and Outcomes in an Italian Trauma Center

Introduction:

Major trauma is the leading cause of mortality in the world in patients younger than 40 years. However, the proportion of elderly people who suffer trauma has increased significantly. The purpose of this study is to assess the correlation of old age with mortality and other unfavorable outcomes.

Methods:

We assessed on one hand, anatomical criteria such as ISS values and the number of body regions affected, on the other hand, hemodynamic instability criteria, various shock indices, and Glasgow Coma Scale. Finally, we also evaluated biochemical parameters, such as lactate, BE, and pH values. We conducted a prospective and monocentric observational study of all the patients referred to the Emergency Department of the IRCCS Fondazione Policlinico S. Matteo in Pavia for major trauma in 13 consecutive months: January 1, 2018–January 30, 2019. We compared the elderly population (>75 years) and the younger population (≤75).

Results:

We included 501 patients, among which 10% were over the age of 75 years. The mortality rate was higher among the older patients than among the younger (4% vs. 1.33%; P = 0.050). Hemodynamic instability was more common in the older patients than in the younger (26% vs. 9%; P < 0.001). More older patients (44%) had an ISS >16, in comparison with 32% of younger patients (P = 0.01).

Conclusions:

The elderly showed worse outcomes in terms of mortality, hospitalization rate, hemodynamic instability criteria, and anatomical and biochemical parameters.

Factors Associated with Improved Quality of Life Outcomes in Patients Undergoing Surgery for Adult Spinal Deformity

STUDY DESIGN

Retrospective longitudinal cohort study.

OBJECTIVE

This study aimed to elucidate factors affecting the likelihood of achieving minimum clinically important difference (MCID) to patient-reported outcomes defined by the Scoliosis Research Society-22r (SRS-22r) among patients with adult spinal deformity (ASD) who underwent extensive corrective fusion surgery from the thoracic spine to the pelvis.

SUMMARY OF BACKGROUND DATA

Achieving MCID for SRS-22r parameters was a measure of surgical efficacy. Patient characteristics and surgical and radiographic factors that affect the likelihood of achieving MCID for SRS-22r parameters are unknown.

METHODS

Data from patients with ASD who underwent extensive corrective fusion surgery from the thoracic spine to the pelvis during 2010 to 2016 were retrospectively reviewed. Data from a total of 167 patients with ≥2 years of follow-up were included. Multivariate analysis was used to investigate factors associated with the likelihood of achieving MCID for each of the SRS-22r domains (Function, Pain, Subtotal) 2 years after surgery. The following MCID values were used: 0.90 for Function, 0.85 for Pain, and 1.05 for the Subtotal.

RESULTS

MCID achievement rate was 36.5% for Function, 46.1% for Pain, and 44.3% for the Subtotal domain. In multivariate analysis, preoperative SRS-22r Function (odds ratio [OR] = 0.204, 95% confidence interval [CI] 0.105-0.396) increased the likelihood of achieving MCID for SRS-22r Function. Preoperative SRS-22r Subtotal (OR = 0.211, 95% CI, 0.107-0.413), preoperative pelvic tilt (OR = 1.072, 95% CI, 1.012-1.136), preoperative pelvic incidence minus lumbar lordosis (OR = 0.965, 95% CI, 0.934-0.997), and postoperative sagittal vertical axis (OR = 0.985, 95% CI, 0.974-0.995) affected the likelihood of achieving MCID for the SRS-22r Subtotal.

CONCLUSION

Patients with poor preoperative health-related quality of life were more likely to achieve improvement in SRS-22r parameters after extensive corrective fusion surgery for ASD. Achieving postoperative sagittal alignment increased the likelihood of achieving MCID for the SRS-22r Subtotal domain.Level of Evidence: 3.

Long-term benefits of appropriately corrected sagittal alignment in reconstructive surgery for adult spinal deformity: evaluation of clinical outcomes and mechanical failures

OBJECTIVE

It has been well documented that optimal sagittal alignment is highly correlated with good clinical outcomes in adult spinal deformity (ASD) surgery. However, it remains to be determined whether the clinical benefit of appropriately corrected sagittal alignment can be maintained in the long term. Therefore, the aim of this study was to investigate whether appropriately corrected sagittal alignment continues to offer benefits over time with regard to clinical outcomes and mechanical failure.

METHODS

Patients older than 50 years who underwent ≥ 4-level fusion for ASD and were followed up for ≥ 5 years were included in this study. Appropriateness of sagittal alignment correction was defined as pelvic incidence minus lumbar lordosis ≤ 10°, pelvic tilt ≤ 25°, and sagittal vertical axis ≤ 50 mm. Two groups were created based on this appropriateness: group A (appropriate) and group IA (inappropriate). Clinical outcomes were evaluated using the visual analog scale (VAS), Oswestry Disability Index (ODI), and Scoliosis Research Society Outcomes Questionnaire-22 (SRS-22). The development of mechanical failures, such as rod fracture and proximal junctional kyphosis (PJK), was compared between the two groups.

RESULTS

The study included 90 patients with a follow-up duration of 90.3 months. There were 30 patients in group A and 60 patients in group IA. The clinical outcomes at 2 years were significantly better in group A than in group IA in terms of the VAS scores, ODI scores, and all domains of SRS-22. At the final follow-up visit, back VAS and ODI scores were still lower in group A than they were in group IA, but the VAS score for leg pain did not differ between the groups. The SRS-22 score at the final follow-up showed that only the pain and self-image/appearance domains and the total sum were significantly higher in group A than in group IA. The incidence of rod fracture and PJK did not differ between the two groups. The rate of revision surgery for rod fracture or PJK was also similar between the two groups.

CONCLUSIONS

The clinical benefits from appropriate correction of sagittal alignment continued for a mean of 90.3 months. However, the intergroup difference in clinical outcomes between groups A and IA decreased over time. The development of rod fracture or PJK was not affected by the appropriateness of sagittal alignment.

Lower Satisfaction After Adult Spinal Deformity Surgery in Japan Than in the United States Despite Similar SRS-22 Pain and Function Scores: A Propensity-Score Matched Analysis

STUDY DESIGN

A multicenter retrospective case series.

OBJECTIVE

The purpose of this study was to compare the clinical outcomes of a surgical treatment for adult spinal deformity (ASD) in the United States (US) with those in Japan (JP) in a matched cohort.

SUMMARY OF BACKGROUND DATA

Surgical outcomes of thoracic-lumbar-sacral (TLS) spinal fusions in adult spinal deformity ASD patients who live in Asian countries are poorly understood.

METHODS

A total of 300 surgically treated ASDs of age more than 50 years with the lowest instrumented vertebra at the pelvis and a minimum follow-up of 2 years (2y) were consecutively included. Patients were propensity-score matched for age, sex, levels fused, and 2y postop sagittal spinal alignment. Demographic, surgical, and radiographic parameters were compared between the US and JP groups.

RESULTS

A total of 186 patients were matched by propensity score and were almost identical within these parameters: age (US vs. JP: 66 ± 8 vs. 65 ± 7 yr), sex (females: 90% vs. 89%), levels fused (10 ± 3 vs. 10 ± 2), 2y C7 sagittal vertical axis (C7SVA) (5 ± 5 vs. 5 ± 4 cm), 2y Pelvic incidence minus lumbar lordosis (9 ± 15° vs. 9 ± 15°), and 2y pelvic tilt (PT) (25 ± 10° vs. 24 ± 10°). Oswestry Disability Index (ODI) scores and Scoliosis Research Society patient questionnaire ((SRS-22) function and pain scores were similar at 2y between the US and JP groups (ODI: 27 ± 19% vs. 28 ± 14%, P = 0.72; SRS-22 function: 3.6 ± 0.9 vs. 3.6 ± 0.7, P = 0.54; SRS-22 pain: 3.6 ± 1.0 vs. 3.8 ± 0.8, P = 0.11). However, significantly lower satisfaction was observed in JP than in the US (SRS-22 satisfaction: 4.3 ± 0.9 vs. 4.0 ± 0.8, P < 0.01).

CONCLUSION

Surgical treatment for ASD was similarly effective in patients in the US and in JP. However, satisfaction scores were lower in JP compared with the US. Differences in lifestyle and cultural expectations may impact patient satisfaction following ASD surgery.

LEVEL OF EVIDENCE

3.

Influence of spino-pelvic and postural alignment parameters on gait kinematics

INTRODUCTION

Postural alignment is altered with spine deformities that might occur with age. Alteration of spino-pelvic and postural alignment parameters are known to affect daily life activities such as gait. It is still unknown how spino-pelvic and postural alignment parameters are related to gait kinematics.

RESEARCH QUESTION

To assess the relationships between spino-pelvic/postural alignment parameters and gait kinematics in asymptomatic adults.

METHODS

134 asymptomatic subjects (aged 18-59 years) underwent 3D gait analysis, from which kinematics of the pelvis and lower limbs were extracted in the 3 planes. Subjects then underwent full-body biplanar X-rays, from which skeletal 3D reconstructions and spino-pelvic and postural alignment parameters were obtained such as sagittal vertical axis (SVA), center of auditory meatus to hip axis plumbline (CAM-HA), thoracic kyphosis (TK) and radiologic pelvic tilt (rPT). In order to assess the influence of spino-pelvic and postural alignment parameters on gait kinematics a univariate followed by a multivariate analysis were performed.

RESULTS

SVA was related to knee flexion during loading response (β = 0.268); CAM-HA to ROM pelvic obliquity (β = -0.19); rPT to mean pelvic tilt (β = -0.185) and ROM pelvic obliquity (β = -0.297); TK to ROM hip flexion/extension in stance (β = -0.17), mean foot progression in stance (β = -0.329), walking speed (β = -0.19), foot off (β = 0.223) and step length (β = -0.181).

SIGNIFICANCE

This study showed that increasing SVA, CAM-HA, TK and rPT, which is known to occur in adults with spinal deformities, could alter gait kinematics. Increases in these parameters, even in asymptomatic subjects, were related to a retroverted pelvis during gait, a reduced pelvic obliquity and hip flexion/extension mobility, an increased knee flexion during loading response as well as an increase in external foot progression angle. This was associated with a decrease in the walking pace: reduced speed, step length and longer stance phase.