Sagittal Spinopelvic Malalignment Research Articles

Locomotive Syndrome and Lumbar Spine Disease: A Systematic Review.

Locomotive syndrome (LS) is defined based on the Loco-Check, 25-question Geriatric Locomotive Function Scale (GLFS-25), 5-question Geriatric Locomotive Function Scale (GLFS-5), Stand-Up Test, Two-Step Test, or a total assessment (i.e., positive for one or more of the GLFS-25, Stand-Up Test, and Two-Step Test). Lumbar spine disease has been reported to be one of the most common musculoskeletal disorders leading to LS. We therefore conducted a systematic review via PubMed, Google Scholar, Cochrane Library, Web of Science, and MEDLINE, based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A total of 26 studies were considered to be eligible for inclusion in this systematic review. The GLFS-25 showed an association with low back pain, sagittal spinopelvic malalignment, and lumbar spinal stenosis but not vertebral fracture. The GLFS-5 showed an association with low back pain and lumbar spinal stenosis. The Loco-Check and Two-Step Test showed an association with low back pain, sagittal spinopelvic malalignment, and lumbar spinal stenosis. The Stand-Up Test showed no association with lumbar spinal stenosis. The total assessment showed an association with low back pain and lumbar spinal stenosis. Furthermore, the GLFS-25, Two-Step Test, and total assessment were improved by spinal surgery for lumbar spinal stenosis. The current evidence concerning the relationship between LS and lumbar spine disease still seems insufficient, so further investigations are required on this topic.

Association between sagittal spinopelvic alignment and femoral head destruction in the early stage of rapidly destructive coxopathy.

AimsThis study aimed to evaluate sagittal spinopelvic alignment (SSPA) in the early stage of rapidly destructive coxopathy (RDC) compared with hip osteoarthritis (HOA), and to identify risk factors of SSPA for destruction of the femoral head within 12 months after the disease onset.MethodsThis study enrolled 34 RDC patients with joint space narrowing > 2 mm within 12 months after the onset of hip pain and 25 HOA patients showing femoral head destruction. Sharp angle was measured for acetabular coverage evaluation. Femoral head collapse ratio was calculated for assessment of the extent of femoral head collapse by RDC. The following parameters of SSPA were evaluated using the whole spinopelvic radiograph: pelvic tilt (PT), sacral slope (SS), pelvic incidence (PI), sagittal vertical axis (SVA), thoracic kyphosis angle (TK), lumbar lordosis angle (LL), and PI-LL.ResultsThe HOA group showed higher Sharp angles compared with the RDC group. PT and PI-LL were higher in the RDC group than the HOA group. SS and LL were lower in the RDC group than the HOA group. No difference was found in PI, SVA, or TK between the groups. Femoral head collapse ratio was associated with PT, SS, SVA, LL, and PI-LL. A PI-LL > 20° and a PT > 30° correlated with greater extent of femoral head destruction by RDC. From regression analysis, SS and SVA were significantly associated with the femoral head collapse ratio within 12 months after disease onset.ConclusionCompared with HOA, RDC in the early stage correlated with sagittal spinopelvic malalignment. SS and SVA may partially contribute to the extent of femoral head destruction by RDC within 12 months after the onset of hip pain. The present study indicates a potential role of SSPA assessment in identification of RDC patients at risk for subsequent bone destruction.Cite this article: Bone Jt Open 2022;3(1):77–84.

Strategies for prevention of rod fracture in adult spinal deformity: cobalt chrome rod, accessory rod technique, and lateral lumbar interbody fusion.

Restoring the proper sagittal alignment in adult spinal deformity (ASD) can improve radiological and clinical outcomes, but pseudarthrosis including rod fracture (RF) is a common problematic complication. The purpose of this study was to analyze the methods for reducing the incidence of RF in deformity correction of ASD. The authors retrospectively selected 178 consecutive patients (mean age 70.8 years) with lumbar degenerative kyphosis (LDK) who underwent deformity correction with a minimum 2-year follow-up. Patients were classified into the non-RF group (n = 131) and the RF group (n = 47). For predicting the crucial factors of RF, patient factors, radiographic parameters, and surgical factors were analyzed. The overall incidence of RF was 26% (47/178 cases), occurring in 42% (42/100 cases) of pedicle subtraction osteotomy (PSO), 7% (5/67 cases) of lateral lumbar interbody fusion (LLIF) with posterior column osteotomy, 18% (23/129 cases) of cobalt chrome rods, 49% (24/49 cases) of titanium alloy rods, 6% (2/36 cases) placed with the accessory rod technique, and 32% (45/142 cases) placed with the 2-rod technique. There were no significant differences in the incidence of RF regarding patient factors between two groups. While both groups showed severe sagittal imbalance before operation, lumbar lordosis (LL) was more kyphotic and pelvic incidence (PI) minus LL (PI-LL) mismatch was greater in the RF group (p < 0.05). Postoperatively, while LL and PI-LL did not show significant differences between the two groups, LL and sagittal vertical axis correction were greater in the RF group (p < 0.05). Nonetheless, at the last follow-up, the two groups did not show significant differences in radiographic parameters except thoracolumbar junctional angles. As for surgical factors, use of the cobalt chrome rod and the accessory rod technique was significantly greater in the non-RF group (p < 0.05). As for the correction method, PSO was associated with more RFs than the other correction methods, including LLIF (p < 0.05). By logistic regression analysis, PSO, preoperative PI-LL mismatch, and the accessory rod technique were crucial factors for RF. Greater preoperative sagittal spinopelvic malalignment including preoperative PI-LL mismatch was the crucial risk factor for RF in LDK patients 65 years or older. For restoring and maintaining sagittal alignment, use of the cobalt chrome rod, accessory rod technique, or LLIF was shown to be effective for reducing RF in ASD surgery.

Dynamic sagittal alignment and compensation strategies in adult spinal deformity during walking

BACKGROUND CONTEXTRadiographic evaluation in adult spinal deformity (ASD) offers no information on spinopelvic alignment and compensation during dynamic conditions. Motion analysis offers the potential to bridge the gap between static radiographic and dynamic alignment measurement, increasing our understanding on how ASD impacts function. PURPOSEThis study aimed to explore the changes in sagittal alignment and compensation strategies in ASD between upright standing and walking, compared to control subjects and within different sagittal alignment groups. Ten patients were measured pre- and six months postoperatively to explore the impact of surgical alignment correction on gait. STUDY DESIGNProspective study. SAMPLE SIZEFull protocol: 58 ASD and 20 controls; Spinal kinematic analysis: 43 ASD and 18 controls; Postoperative analysis: 10 ASD. OUTCOME MEASURESStanding and walking sagittal spinopelvic (thoracic kyphosis (TK), lumbar lordosis (LL), sagittal vertical axis (SVA), pelvis), and lower limb kinematics, spinopelvic changes between standing and walking (∆ ie, difference between mean dynamic and static angle), lower limb kinetics, spatiotemporal parameters, balance (BESTest), patient-reported outcome scores (SRS-22r, ODI, and FES-I) and radiographic parameters. METHODSMotion analysis was used to assess the standing and walking spinopelvic and lower limb kinematics, as well as the lower limb kinetics during walking. All parameters were compared between controls and patients with ASD, divided in three groups based on their sagittal alignment (ASD 1: decompensated sagittal malalignment; ASD 2: compensated sagittal malalignment; ASD 3: scoliosis and normal sagittal alignment). Ten patients were reassessed 6 months after spinal corrective surgery. Continuous kinematic and kinetic data were analyzed through statistical parametric mapping. RESULTSAll patient groups walked with increased forward trunk tilt (∆SVA=41.43 mm, p<.001) in combination with anterior pelvic tilt (∆Pelvis=2.58°, p<.001) compared to standing, as was also observed in controls (∆SVA=37.86 mm, p<.001; ∆Pelvis=1.62°, p=.012). Patients walked with increased SVA, in combination with decreased LL and alterations in lower limb kinematics during terminal stance and initial swing, as well as altered spatiotemporal parameters. Subgroup analysis could link these alterations in gait to sagittal spinopelvic malalignment (ASD 1 and 2). After surgical correction, lower limb kinematics and spatiotemporal parameters during gait were not significantly improved. CONCLUSIONSTo compensate for increased trunk tilt and pelvic anteversion during walking, patients with sagittal malalignment show altered lower limb gait patterns, which have previously been associated with increased risk of falling and secondary lower limb pathology. Since surgical correction of the deformity did not lead to gait improvements, further research on the underlying mechanisms is necessary to improve our understanding of how ASD impacts function.

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

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

Spontaneous correction of sagittal spinopelvic malalignment after decompression surgery without corrective fusion procedure for lumbar spinal stenosis and its impact on clinical outcomes: A systematic review

BackgroundThe impact of a positive sagittal vertical axis (SVA) on the surgical outcome for lumbar spinal stenosis (LSS) remains unclear, because sagittal imbalance in LSS may partly result from the tendency of patients to lean forward to reduce symptoms. Such an abnormality could be normalized by decompression surgery alone without corrective fusion. As this spontaneous correction is not well known, some surgeons perform only neural decompression in patients with positive SVA and decreased lumbar lordosis (LL), unless flatback-related symptoms are present, whereas other surgeons add corrective fusion to restore spinopelvic alignment. We systematically reviewed previous studies on this issue. MethodsPubMed, Cochrane Library, and Embase were searched for English articles on the relationship between SVA and decompression surgery for LSS. The rates of spontaneous correction in spinopelvic parameters and the impact of SVA on clinical outcomes were analyzed. ResultsThe rate of spontaneous SVA correction from >40–50 mm to normal values following decompression surgery alone varied from 25% to 73%. Overall, the spinopelvic parameters tended to improve postoperatively, with statistically significant changes in some series. Postoperative residual sagittal imbalance, rather than preoperative imbalance, more consistently showed a negative impact on clinical outcomes, but not on leg symptoms. For predicting postoperative sagittal imbalance, 2 studies identified the cutoff of >20° for preoperative PI-LL mismatch. Another study suggested SVA >80 mm as a useful value for this purpose. ConclusionIn LSS treated with decompression surgery alone, postoperative rather than preoperative sagittal imbalance more consistently affects clinical outcomes, particularly low back pain. This is probably because decompression usually partly improves preoperative spinopelvic sagittal malalignment. Thus, LSS, if associated with preoperative PI-LL mismatch <20° and SVA <80 mm, may not require additional corrective fusion procedures.

Sagittal reconstruction of lumbosacral contiguous double-level spondylolytic spondylolisthesis: a comparison of double-level and single-level transforaminal lumbar interbody fusion

BackgroundContiguous double-level lumbar spondylolytic spondylolisthesis is an extremely rare condition. There is a paucity of data of lumbosacral deformity and sagittal spino-pelvic malalignment among these patients. Moreover, the effect of transforaminal lumbar interbody fusion (TLIF) on sagittal realignment still remains largely unknown. The aim of the study is to investigate the reconstruction of sagittal alignment and the improvement of clinical outcomes after posterior instrumented double-level or single-level TLIF.MethodsFrom January 2010 to September 2018, the records of patients with contiguous L4/5 and L5/S1 double-level spondylolytic spondylolisthesis were retrospectively reviewed. Patients who had undergone double-level or single-level TLIF and a minimum of 2 years’ follow-up were included. The slippage parameters and spino-pelvic parameters were measured preoperatively, postoperatively, and at the latest follow-up.ResultsA total of 58 patients (21 males and 37 females, mean age of 57.1 ± 6.9 years) were enrolled. Thirty-eight patients were treated with double-level TLIF and the remaining 20 with single-level TLIF (L4/5 in 14; L5/S1 in 6). After surgery, the spondylolisthesis was significantly reduced at both L4/5 and L5/S1 level (all P < 0.001). There was a significant reduction in pelvic tilt (P < 0.001) and a significant increase in sacral slope (P < 0.001). Significant increase in L4–S1 height (P < 0.001) and L4–S1 lordosis (P = 0.012) and decrease in L5 slope (P = 0.004) and L5 incidence (P = 0.001) were also observed. Compared to single-level TLIF, double-level TLIF increased L4–S1 height (P < 0.001) and L4–S1 lordosis (P < 0.001) and reduced L4-SVA (P = 0.007) and L5 incidence (P = 0.013) more obviously, and the sagittal balance was better corrected in double-level TLIF group (P = 0.006). Double-level TLIF group showed larger increase in VAS scores for low back pain. The incidence of implant-related complications was lower in the double-level group.ConclusionPosterior short-segment instrumented TLIF can bring favorable radiographic and clinical outcomes in patients with lumbosacral contiguous double-level spondylolytic spondylolisthesis. Double-level TLIF is more efficient to improve L4–S1 height, regional lumbar lordosis, and global sagittal balance.

Sagittal spinopelvic malalignment in degenerative scoliosis patients: isolated correction of symptomatic levels and clinical decision-making

BackgroundThis study aims to determine if (1) loss of lumbar lordosis (LL), often associated with degenerative scoliosis (DS), is structural or rather largely due to positional factors secondary to spinal stenosis; (2) only addressing the symptomatic levels with a decompression and posterolateral fusion in carefully selected patients will result in improvement of sagittal malalignment; and (3) degree of sagittal plane correction achieved with such a local fusion could be predicted by routine pre-operative imaging.MethodsA retrospective study design with prospectively collected imaging data of a consecutive series of surgically treated DS patients who underwent decompression and instrumented fusion at only symptomatic levels was performed. Pre- and post-operative plain radiographs and pre-operative magnetic resonance imaging (MRIs) of the spinopelvic region were analyzed. LL, pelvic incidence (PI), pelvic tilt (PT), and sacral slope (SS) were assessed in all patients. As a requirement for the surgical strategy, all patients presented with a pre-operative PI-LL mismatch greater than 10°. Post-operative complications were assessed.ResultsPre-operative MRIs and lumbar extension radiographs revealed a mean LL of 42° (range 10–66°) and 48° (range 20–74°), respectively, in 68 patients (mean follow-up 29 months). LL post-operatively was corrected to a mean PI-LL of 10°. Of patients who achieved PI-LL mismatch within 10o on their pre-operative extension lateral lumbar radiographs, 62.5% were able to maintain a PI-LL mismatch within 10° on their initial post-operative films. Only 37.5% were not able to achieve that mismatch on extension radiographs (p = 0.001, OR = 9.58). Similarly, 54.2% were able to achieve a PI-LL < 10° on initial post-operative radiographs, when pre-operative MRI revealed a PI-LL mismatch within 10°. In contrast, only 20.5% achieved that goal post-operatively if their mismatch was greater than 10o on their MRI (p = 0.003, OR = 4.25).ConclusionWith a decompression and instrumented fusion of only the symptomatic levels in symptomatic DS patients, we were able to achieve a PI-LL mismatch to within 10°. The loss of LL observed pre-operatively may be largely positional rather than structural. The amount of LL correction observed immediately after surgery can be predicted from pre-operative lumbar extension radiographs and supine sagittal MRI.

Spinopelvic Changes Based on the Simplified SRS-Schwab Adult Spinal Deformity Classification: Relationships With Disability and Health-Related Quality of Life in Adult Patients With Prolonged Degenerative Spinal Disorders.

Cross-sectional, observational study. To study the occurrence of sagittal malalignment, the adaptability of a simplified sagittal modifiers grading of the Scoliosis Research Society (SRS)-Schwab adult spinal deformity (ASD) classification, and the deformity-specific SRS questionnaire version 30 (SRS-30) in an unselected adult cohort with symptomatic degenerative spinal disorders. The sagittal modifiers of the SRS-Schwab ASD classification correlate with health-related quality of life (HRQoL) measures in patients with ASD. The deformities and disabilities caused by sagittal malalignment in patients with common degenerative spinal disorders of multiple etiologies are rarely studied. A simplified and categorizing version of the SRS-Schwab ASD classification in relation to the Oswestry Disability Index (ODI) and the SRS-30 outcomes has not yet been developed. We recruited 874 consecutive patients with degenerative spinal disorders between March 2013 and February 2014. Full spine radiographs were taken and the patients divided into sagittal deformity severity groups: mild or none, moderate, and marked deformity. Participants completed the ODI, SRS-30, and a general health questionnaire. We included 637 patients in the analysis. The severity of sagittal deformity was mild or none in 407 (63.9%) patients, moderate in 159 (25.0%), and marked in 71 (11.1%). Linearity across the modifier grades and deformity classes was found for ODI total score (P = 0.033), and the function/activity (P = 0.004) and self-image/appearance (P = 0.030) domains of the SRS-30. Age, body mass index, duration of symptoms, and the use of painkillers increased while physical activity, working, and educational status decreased significantly with deformity severity. Sagittal spinopelvic malalignment is significantly related to deterioration of the ODI and the SRS-30 in symptomatic adults with degenerative spinal disorders. The SRS-Schwab classification sagittal modifiers categorized into three groups is a practical tool to detect various clinically significant grades of deformity in a cohort with no recognized ASD. 3.

Factors Associated with Neck and Shoulder Pain in Volunteers.

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.

When is compensation for lumbar spinal stenosis a clinical sagittal plane deformity?

Background ContextDegenerative lumbar stenosis (DLS) patients have been reported to lean forward in an attempt to provide neural decompression. Spinal alignment in patients with DLS may resemble that of adult spinal deformity (ASD). No previous studies have compared and contrasted the compensatory mechanisms of DLS and ASD patients. PurposeThis study aimed to determine the differences in compensatory mechanisms between DLS and ASD patients with increasing severity of sagittal spinopelvic malalignment. Contrasting these compensatory mechanisms may help determine at what severity sagittal malalignment represents a clinical sagittal deformity rather than a compensation for neural compression. Study Design/SettingThis is a retrospective clinical and radiological review. Patient SampleBaseline x-rays in patients without spinal instrumentation, with the clinical radiological and diagnoses of DLS or ASD, were assessed for patterns of spinopelvic compensatory mechanisms. Patients were stratified by sagittal vertical axis (SVA) according to the Scoliosis Research Society-Schwab [SRS-Schwab] classification. Outcome MeasuresRadiographic spinopelvic parameters were measured in the DLS and ASD groups, including SVA, pelvic incidence−lumbar lordosis mismatch (PI−LL), T1 spinopelvic inclination (T1SPi), T1 pelvic angle (TPA), and pelvic tilt (PT). MethodsThe two diagnosis cohorts were propensity-matched for PI and age. Each group contained 125 patients and was stratified according to the SRS-Schwab classification. Regional spinopelvic,lower limb, and global alignment parameters were assessed to identify differences in compensatory mechanisms between the two groups with differing degrees of deformity. No funding was provided by any third party in relation to carrying out this study or preparing the manuscript. ResultsWith mild to moderate malalignment (SRS-Schwab groups “0,” or “+” for PT, PI−LL, or SVA), DLS patients permit anterior truncal inclination and recruit posterior pelvic shift instead of pelvic tilt to maintain balance, while providing relief of neurologic symptoms. Adult spinal deformity patients with mild to moderate deformity recruit pelvic tilt earlier than DLS patients. With moderate to severe malalignment, no significant difference was found in compensatory mechanisms between DLS and ASD patients. ConclusionsPatients with DLS permit mild to moderate deformity without recruiting compensatory mechanisms of PT, reducing truncal inclination and thoracic hypokyphosis to achieve neural decompression. However, with moderate to severe deformity, their desire for upright posture overrides the desire for neural decompression, evident by the adaptation of compensatory mechanisms similar to that of ASD patients.

The effect of total hip arthroplasty on sagittal spinal-pelvic-leg alignment and low back pain in patients with severe hip osteoarthritis.

Sagittal spinopelvic malalignment has been reported in spinal disorders such as low back pain (LBP), and restoration of normal alignment is targeted when treating these disorders. Abnormal sagittal spinal-pelvic-leg alignment has been reported in patients with severe hip osteoarthritis (OA), who have a high prevalence of associated LBP. This prospective longitudinal study aimed to investigate changes in sagittal spinal-pelvic-leg alignment after total hip arthroplasty (THA) in patients with severe hip OA, and whether these changes contribute to LBP relief. Patients undergoing primary THA due to severe unilateral hip OA were recruited. Physical examination and X-ray films were taken to rule out any spinal disorder. Sagittal alignment of pelvis, hip, and spine was analyzed on lateral radiographs taken before (baseline) and 1year after (follow-up) THA. Functional instruments were completed by patients including: visual analog scale (VAS) for LBP, Roland-Morris Disability Questionnaire (RMDQ), and Harris Hip Score (HHS). Comparisons were carried out at baseline and follow-up, and between patients with and without LBP. The recruited 69 patients showed significantly reduced hip flexion and improved global spinal balance at follow-up compared with baseline. LBP was reported by 39 patients (56.5%) before surgery; at follow-up, 17 reported complete resolution, while 22 reported significant relief. Significant decreases in VAS and RMDQ scores in lumbar spine and increase in hip HHS were observed. THA in patients with severe hip OA could help correct abnormal sagittal spinal-pelvic-leg alignment and relieve comorbid LBP. Improvements in hip flexion and global spinal balance might be involved in the mechanism of LBP relief.

Assessment of impact of standing long-cassette radiographs on surgical planning for lumbar pathology: an international survey of spine surgeons.

OBJECT The associations among global spinal alignment, patient-reported disability, and surgical outcomes have increasingly gained attention. The assessment of global spinal alignment requires standing long-cassette anteroposterior and lateral radiographs; however, spine surgeons routinely rely only on short-segment imaging when evaluating seemingly isolated lumbar pathology. This may prohibit adequate surgical planning and may predispose surgeons to not recognize associated pathology in the thoracic spine and sagittal spinopelvic malalignment. The authors used a case-based survey questionnaire to evaluate if including long-cassette radiographs led to changes to respondents' operative plans as compared with their chosen plan when cases contained standard imaging of the involved lumbar spine only. METHODS A case-based survey was distributed to AOSpine International members that consisted of 15 cases of lumbar spine pathology and lumbar imaging only. The same 15 cases were then shuffled and presented a second time with additional long-cassette radiographs. Each case required participants to select a single operative plan with 5 choices ranging from least to most extensive. The cases included 5 "control" cases with normal global spinal alignment and 10 "test" cases with significant sagittal and/or coronal malalignment. Mean scores were determined for each question with higher scores representing more invasive and/or extensive operative plans. RESULTS Of 712 spine surgeons who started the survey, 316 (44%) completed the entire series, including 68% of surgeons with spine fellowship training and representation from more than 40 countries. For test cases, but not for control cases, there were significantly higher average surgical invasiveness scores for cases presented with long-cassette radiographs (4.2) as compared with those cases with lumbar imaging only (3.4; p = 0.002). The addition of long-cassette radiographs resulted in 82.1% of respondents recommending instrumentation up to the thoracic spine, a 23.2% increase as compared with the same cases presented with lumbar imaging only (p = 0.008). CONCLUSIONS This study demonstrates the importance of maintaining a low threshold for performing standing long-cassette imaging when assessing seemingly isolated lumbar pathology. Such imaging is necessary for the assessment of spinopelvic and global spinal alignment, which can be important in operative planning. Deformity, particularly positive sagittal malalignment, may go undetected unless one maintains a high index of suspicion and obtains long-cassette radiographs. It is recommended that spine surgeons recognize the prevalence and importance of such deformity when contemplating operative intervention.

Sagittal spinopelvic malalignment in Parkinson disease: prevalence and associations with disease severity.

Prospective study. Our objectives were to evaluate the prevalence of sagittal spinopelvic malalignment in a consecutive series of patients with Parkinson disease (PD) and to identify factors associated with sagittal spinopelvic deformity in this population. PD is a degenerative neurological condition characterized by tremor, rigidity, bradykinesia, and loss of postural reflexes. The prevalence of spinal deformity in PD is higher than that of age-matched adults without PD. This study was a prospective assessment of consecutive patients with PD presenting to a neurology clinic during 12 months. Inclusion criteria included age more than 21 years and diagnosis of PD. Age- and sex-matched control group was selected from patients with cervical spondylosis. Clinical and demographic factors were collected including Unified Parkinson Disease Rating Scale score and Hoehn and Yahr stage. Full-length standing spine radiographs were assessed. Patients were grouped into either low C7 sagittal vertical axis (SVA) (<5 cm) or high C7 SVA (≥5 cm) and into matched (≤10°) or mismatched (>10°) pelvic incidence (PI)-lumbar lordosis. Eighty-nine patients met criteria (41 males/48 females), including 52 with low C7 SVA and 37 with high C7 SVA. Significantly higher prevalence of high C7 SVA was found in PD (41.6 vs. 16.8%; P < 0.001). The high C7 SVA group was significantly older (72.4 vs. 65.1 yr; P < 0.001) and had a higher proportion of females (68% vs. 44%; P = 0.034), greater severity of PD based on Hoehn and Yahr stage (1.89 vs. 1.37; P < 0.001) and Unified Parkinson Disease Rating Scale (30.5 vs. 17.2; P = 0.002. Unified Parkinson Disease Rating Scale significantly correlated with C7 SVA (r = 0.474). Compared with the matched (≤10°) PI-lumbar lordosis group, the mismatch PI-lumbar lordosis group had higher C7 SVA, higher PI, higher pelvic tilt, lower lumbar lordosis, and lower thoracic kyphosis (P ≤ 0.003). Patients with PD have a high prevalence of sagittal spinopelvic malalignment than control group patients. Greater severity of PD is associated with sagittal spinopelvic malalignment. 3.

Surgical treatment of pathological loss of lumbar lordosis (flatback) in patients with normal sagittal vertical axis achieves similar clinical improvement as surgical treatment of elevated sagittal vertical axis: clinical article.

Increased sagittal vertical axis (SVA) correlates strongly with pain and disability for adults with spinal deformity. A subset of patients with sagittal spinopelvic malalignment (SSM) have flatback deformity (pelvic incidence-lumbar lordosis [PI-LL] mismatch > 10°) but remain sagittally compensated with normal SVA. Few data exist for SSM patients with flatback deformity and normal SVA. The authors' objective was to compare baseline disability and treatment outcomes for patients with compensated (SVA < 5 cm and PI-LL mismatch > 10°) and decompensated (SVA > 5 cm) SSM. The study was a multicenter, prospective analysis of adults with spinal deformity who consecutively underwent surgical treatment for SSM. Inclusion criteria included age older than 18 years, presence of adult spinal deformity with SSM, plan for surgical treatment, and minimum 1-year follow-up data. Patients with SSM were divided into 2 groups: those with compensated SSM (SVA < 5 cm and PI-LL mismatch > 10°) and those with decompensated SSM (SVA ≥ 5 cm). Baseline and 1-year follow-up radiographic and health-related quality of life (HRQOL) outcomes included Oswestry Disability Index, Short Form-36 scores, and Scoliosis Research Society-22 scores. Percentages of patients achieving minimal clinically important difference (MCID) were also assessed. A total of 125 patients (27 compensated and 98 decompensated) met inclusion criteria. Compared with patients in the compensated group, patients in the decompensated group were older (62.9 vs. 55.1 years; p = 0.004) and had less scoliosis (43° vs 54°; p = 0.002), greater SVA (12.0 cm vs. 1.7 cm; p < 0.001), greater PI-LL mismatch (26° vs. 20°; p = 0.013), and poorer HRQOL scores (Oswestry Disability Index, Short Form-36 physical component score, Scoliosis Research Society-22 total; p ≤ 0.016). Although these baseline HRQOL differences between the groups reached statistical significance, only the mean difference in Short Form-36 physical component score reached threshold for MCID. Compared with baseline assessment, at 1 year after surgery improvement was noted for patients in both groups for mean SVA (compensated -1.1 cm, decompensated +4.8 cm; p ≤ 0.009), mean PI-LL mismatch (compensated 6°, decompensated 5°; p < 0.001), and all HRQOL measures assessed (p ≤ 0.005). No significant differences were found between the compensated and decompensated groups in the magnitude of HRQOL score improvement or in the percentages of patients achieving MCID for each of the outcome measures assessed. Decompensated SSM patients with elevated SVA experience significant disability; however, the amount of disability in compensated SSM patients with flatback deformity caused by PI-LL mismatch but normal SVA is underappreciated. Surgical correction of SSM demonstrated similar radiographic and HRQOL score improvements for patients in both groups. Evaluation of SSM should extend beyond measuring SVA. Among patients with concordant pain and disability, PI-LL mismatch must be evaluated for SSM patients and can be considered a primary indication for surgery.

Surgical Treatment of Pathological Loss of Lumbar Lordosis (Flatback) in the Setting of Normal Sagittal Vertical Axis (SVA) Achieves Similar Clinical Improvement as Surgical Treatment for Elevated SVA

Increased sagittal vertical axis (SVA) correlates strongly with pain and disability in adult spinal deformity (ASD). However, increased SVA is caused by failure of physiological compensatory mechanisms to maintain upright posture, with resultant sagittal decompensation. A subset of patients with sagittal spinopelvic malalignment (SSM) have flat back deformity (pelvic incidence-lumbar lordosis mismatch; PI-LL >10°) but remain sagittally compensated with normal SVA. Few data exist for SSM patients with flat back deformity and normal SVA.

Spontaneous improvement of cervical alignment after correction of global sagittal balance following pedicle subtraction osteotomy

Sagittal spinopelvic malalignment is a significant cause of pain and disability in patients with adult spinal deformity. Surgical correction of spinopelvic malalignment can result in compensatory changes in spinal alignment outside of the fused spinal segments. These compensatory changes, termed reciprocal changes, have been defined for thoracic and lumbar regions but not for the cervical spine. The object of this study was to evaluate postoperative reciprocal changes within the cervical spine following lumbar pedicle subtraction osteotomy (PSO). This was a multicenter retrospective radiographic analysis of patients from International Spine Study Group centers. Inclusion criteria were as follows: adults (>18 years old) with spinal deformity treated using lumbar PSO, a preoperative C7-S1 plumb line greater than 5 cm, and availability of pre- and postoperative full-length standing radiographs. Seventy-five patients (60 women, mean age 59 years) were included. The lumbar PSO significantly improved sagittal alignment, including the C7-S1 plumb line, C7-T12 inclination, and pelvic tilt (p <0.001). After lumbar PSO, reciprocal changes were seen to occur in C2-7 cervical lordosis (from 30.8° to 21.6°, p <0.001), C2-7 plumb line (from 27.0 mm to 22.9 mm), and T-1 slope (from -38.9° to -30.4°, p <0.001). Ideal correction of sagittal malalignment (postoperative sagittal vertical alignment < 50 mm) was associated with the greatest relaxation of cervical hyperlordosis (-12.4° vs -5.7°, p = 0.037). A change in cervical lordosis correlated with changes in T-1 slope (r = -0.621, p <0.001), C7-T12 inclination (r = 0.418, p <0.001), T12-S1 angle (r = -0.339, p = 0.005), and C7-S1 plumb line (r = 0.289, p = 0.018). Radiographic parameters that correlated with changes in cervical lordosis on multivariate linear regression analysis included change in T-1 slope and change in C2-7 plumb line (r(2) = 0.53, p <0.001). Adults with positive sagittal spinopelvic malalignment compensate with abnormally increased cervical lordosis in an effort to maintain horizontal gaze. Surgical correction of sagittal malalignment results in improvement of the abnormal cervical hyperlordosis through reciprocal changes.

Sagittal realignment failures following pedicle subtraction osteotomy surgery: are we doing enough?

Pedicle subtraction osteotomy (PSO) is a surgical procedure that is frequently performed on patients with sagittal spinopelvic malalignment. Although it allows for substantial spinopelvic realignment, suboptimal realignment outcomes have been reported in up to 33% of patients. The authors' objective in the present study was to identify differences in radiographic profiles and surgical procedures between patients achieving successful versus failed spinopelvic realignment following PSO. This study is a multicenter retrospective consecutive PSO case series. The authors evaluated 99 cases involving patients who underwent PSO for sagittal spinopelvic malalignment. Because precise cutoffs of acceptable residual postoperative sagittal vertical axis (SVA) values have not been well defined, comparisons were focused between patient groups with a postoperative SVA that could be clearly considered either a success or a failure. Only cases in which the patients had a postoperative SVA of less than 50 mm (successful PSO realignment) or more than 100 mm (failed PSO realignment) were included in the analysis. Radiographic measures and PSO parameters were compared between successful and failed PSO realignments. Seventy-nine patients met the inclusion criteria. Successful realignment was achieved in 61 patients (77%), while realignment failed in 18 (23%). Patients with failed realignment had larger preoperative SVA (mean 217.9 vs 106.7 mm, p < 0.01), larger pelvic tilt (mean 36.9° vs 30.7°, p < 0.01), larger pelvic incidence (mean 64.2° vs 53.7°, p < 0.01), and greater lumbar lordosis-pelvic incidence mismatch (-47.1° vs -30.9°, p < 0.01) compared with those in whom realignment was successful. Failed and successful realignments were similar regarding the vertebral level of the PSO, the median size of wedge resection 22.0° (interquartile range 16.5°-28.5°), and the numerical changes in pre- and postoperative spinopelvic parameters (p > 0.05). Patients with failed PSO realignments had significantly larger preoperative spinopelvic deformity than patients in whom realignment was successful. Despite their apparent need for greater correction, the patients in the failed realignment group only received the same amount of correction as those in the successfully realigned patients. A single-level standard PSO may not achieve optimal outcome in patients with high preoperative spinopelvic sagittal malalignment. Patients with large spinopelvic deformities should receive larger osteotomies or additional corrective procedures beyond PSOs to avoid undercorrection.