A comparison of visual and direct assessments of lumbar spine posture.

BACKGROUND: Posture is assessed clinically and used to guide treatment of low back pain. Collectively, the relevance of posture and clinical postural assessments have come under scrutiny. This study aimed to determine (a) the intra-rater and inter-rater reliability of visual assessments of lumbar lordosis, and (b) the agreement between visual and direct postural assessments. METHODS: Ten physiotherapists visually assessed the lumbar lordosis from 3D scans of 50 asymptomatic participants, and 15 duplicates, using a grading scale of deviations (range: 0 = normal to 3 = severe). Lumbar lordosis angle was directly assessed using the Vitus Smart 3D whole body scanner. Cohen's Kappa was used to determine the intra-rater and inter-rater reliability of visual assessments, with polyserial correlation (ps) used to determine the agreement between visual and direct assessments. RESULTS: Overall, 93% and 83% of all intra-rater and inter-rater differences in visual assessments were within a single grade point, respectively. The intra-rater and inter-rater reliability of visual assessments was moderate (κ (95%CI): 0.56 (0.45, 0.67)) and slight (κ (95%CI): 0.13 (0.08, 0.19)), respectively. The agreement between visual and direct assessments was moderate (ps = -0.41, p = 0.04). CONCLUSION: Visual assessments of lumbar posture demonstrated moderate repeatability and agreement with quantitative assessments. While agreement between assessors was slight, 83% of the visual ratings were within a single grade point, suggesting greater coherence among clinicians than our statistics suggested. As with any clinical assessments involving uncertainty, postural assessment should not solely guide treatment.

Change of cervical flexion range of motion influences postoperative sagittal alignment of the cervical spine after laminoplasty.

OBJECTIVE: The relationships between preoperative cervical spine range of motion (ROM) and postoperative cervical sagittal alignment (CSA), and clinical outcomes after laminoplasty (LMP) have been widely studied. However, the impact of ROM changes on postoperative CSA and clinical outcomes after LMP remains unclear. Herein, patients with cervical spondylotic myelopathy (CSM) were retrospectively analyzed to explore the association between postoperative cervical ROM changes and CSA and surgical outcomes. METHODS: Patients who underwent cervical LMP at our hospital between January 2019 to June 2022 were retrospectively reviewed. CSA parameters were measured before the surgery and at the final follow-up. Loss of cervical lordosis (LCL) was defined as preoperative cervical lordosis (CL) - postoperative CL. An increase in the cervical sagittal vertical axis (I-cSVA) was defined as postoperative cervical sagittal vertical axis (cSVA) - preoperative cSVA. We defined the changes in cervical flexion range of motion (△Flex ROM, preoperative Flex ROM minus postoperative Flex ROM) > 10° as L- Flex ROM group, and △Flex ROM ≤ 10° as S- Flex ROM group. Japanese Orthopedic Association (JOA) score and visual analog score (VAS) were used to assess the surgical outcomes. RESULTS: The study comprised 74 patients and the average follow-up period was 31.83 months. CL, total ROM, and Flex ROM decreased and cSVA increased after cervical LMP. LCL and I-cSVA were positively correlated with △Flex. Multiple linear regression analysis showed that a decrease in the Flex ROM was a risk factor for LCL and I-cSVA after LMP. LCL and I-cSVA were higher in the L-Flex ROM group than in the S-Flex ROM group. Postoperative JOA and the JOA recovery rate were worse in the L-Flex ROM group than in the S-Flex ROM group. CONCLUSIONS: Cervical total and Flex ROM decreased after cervical LMP. The reduction of Flex ROM was associated with LCL and I-cSVA after surgery. The preservation of cervical Flex ROM helps maintain CSA after LMP. Therefore, more attention should be paid to maintaining cervical ROM to obtain good CSA and surgical effects after cervical LMP.

Preoperative spinopelvic hypermobility resolves following total hip arthroplasty.

AIMS: Spinopelvic mobility plays an important role in functional acetabular component position following total hip arthroplasty (THA). The primary aim of this study was to determine if spinopelvic hypermobility persists or resolves following THA. Our second aim was to identify patient demographic or radiological factors associated with hypermobility and resolution of hypermobility after THA. METHODS: This study investigated patients with preoperative posterior hypermobility, defined as a change in sacral slope (SS) from standing to sitting (ΔSSstand-sit) ≥ 30°. Radiological spinopelvic parameters, including SS, pelvic incidence (PI), lumbar lordosis (LL), PI-LL mismatch, anterior pelvic plane tilt (APPt), and spinopelvic tilt (SPT), were measured on preoperative imaging, and at six weeks and a minimum of one year postoperatively. The severity of bilateral hip osteoarthritis (OA) was graded using Kellgren-Lawrence criteria. RESULTS: A total of 136 patients were identified as having preoperative spinopelvic hypermobility. At one year after THA, 95% (129/136) of patients were no longer categorized as hypermobile on standing and sitting radiographs (ΔSSstand-sit < 30°). Mean ΔSSstand-sit decreased from 36.4° (SD 5.1°) at baseline to 21.4° (SD 6.6°) at one year (p < 0.001). Mean SSseated increased from baseline (11.4° (SD 8.8°)) to one year after THA by 11.5° (SD 7.4°) (p < 0.001), which correlates to an 8.5° (SD 5.5°) mean decrease in seated functional cup anteversion. Contralateral hip OA was the only radiological predictor of hypermobility persisting at one year after surgery. The overall reoperation rate was 1.5%. CONCLUSION: Spinopelvic hypermobility was found to resolve in the majority (95%) of patients one year after THA. The increase in SSseated was clinically significant, suggesting that current target recommendations for the hypermobile patient (decreased anteversion and inclination) should be revisited. Cite this article: Bone Joint J 2021;103-B(12):1766-1773.

Fulcrum to Generate Maximum Extension of the Spine and Hip-Proposing A New Strategy using EOS Imaging for Patient-specific Assessment of Degenerated Lumbar Spines.

STUDY DESIGN: A retrospective, radiographic comparative study conducted in a single academic institution. OBJECTIVE: This study aims to compare fulcrum extension with conventional extension imaging to determine maximum "hip lordosis" (HL), an important novel patient-specific parameter in spinal realignment surgery, as well as understand the extension capabilities of the lower lumbar spine, which together, are key contributors to whole-body balancing. SUMMARY OF BACKGROUND DATA: Recent literature recognizes the hip as an important contributor to whole-body lordosis beyond a compensator for spinal imbalance. METHODS: Patients >45 years' old with mechanical low back pain due to degenerative spinal conditions were included and grouped based on the imaging performed-fulcrum or conventional extension. All imaging was performed using EOS under standardized instructions and visual aids. Radiographic parameters include global lumbar angle (GLA), inflexion-S1 (Inf-S1) angle, segmental lumbar angles, pelvic incidence (PI), sacral slope (SS), pelvic tilt (PT), femoral alignment angle (FAA), HL and spinocoxa angle (SCA). Unpaired t test was used to compare between radiographic parameters. RESULTS: One hundred patients (40 males and 60 females, mean age 63.0 years) underwent either fulcrum or conventional extension EOS® imaging. Both groups had comparable baseline radiographic parameters. Fulcrum extension gave a larger mean GLA (-60.7° vs. -48.5°, P = 0.001), Inf-S1 angle (-58.8° vs. -48.8°, P = 0.003), SCA (-36.5° vs. -24.8°, P < 0.001), L4/5 and L5/S1 lordosis (-20.7° vs. -17.7°, P = 0.041, and -22.3° vs. -17.1°, P = 0.018, respectively), compared to conventional extension. PI, SS, PT, FAA, and HL were similar between both extension postures. CONCLUSION: Fulcrum extension, compared to conventional extension, is better at generating lordosis in the lower lumbar spine, thus improving preoperative assessment of stiffness or instability of the lumbar spine. Both extension methods were equally effective at determining the patient-specific maximum HL to assess the flexibility and compensation occurring at the hip, potentially guiding surgical management of patients with degenerative spines.Level of Evidence: 3.

Association of cervical sagittal alignment with adjacent segment degeneration and heterotopic ossification following cervical disc replacement with Prestige-LP disc.

PURPOSE: Cervical sagittal balance plays important roles in transmitting the load of the head and maintaining global spinal balance. This study aimed to identify the association of cervical sagittal alignment with adjacent segment degeneration (ASD) and heterotopic ossification (HO) after Prestige-LP cervical disc replacement (CDR). METHODS: We enrolled 132 patients who underwent one-level Prestige-LP CDR with 2-10 years of follow-up. Cervical sagittal alignment parameters, including the degree of C2-C7 lordosis (CL), functional spinal unit angle (FSUA), sagittal vertical axis (SVA),, and T1 slope (T1s), were measured. ASD and HO were evaluated at the last follow-up. Unpaired t tests and logistic regression analysis were used to identify the associations of cervical sagittal alignment with ASD and HO. RESULTS: We found that patients who developed ASD showed significantly lower FSUA (2.1° vs. -1.4°, p < 0.001) and T1s values (28.4° vs. 25.5°, p = 0.029) after surgery. Similarly, the postoperative CL was significantly better in patients without ASD or HO (18.0° vs. 14.4°, p = 0.043). The decrease in the T1s at the last follow-up was significantly larger in the patients with ASD (-11.0° vs. -3.2°, p = 0.003), HO (-6.7° vs. -2.7°, p = 0.050), and ASD or HO (-7.0° vs. -0.8°, p < 0.001) than in those without ASD or HO. Multivariate logistic regression analysis showed that both the FSUA and T1s are associated with ASD and that the degree of CL is associated with postoperative complications. CONCLUSION: The results imply that maintaining cervical sagittal alignment after Prestige-LP CDR is important.

Comparison between repeat anterior and posterior decompression and fusion in the treatment of two-level symptomatic adjacent segment disease after anterior cervical arthrodesis.

BACKGROUND: Two-level symptomatic adjacent segment disease (ASD) is rarely reported, but remains a challenge after anterior cervical arthrodesis. The purpose of this study was to compare the clinical and radiological outcomes of repeat anterior and posterior decompression and fusion procedures for two-level symptomatic ASD. METHODS: Thirty-two patients with two-level symptomatic ASD were retrospectively reviewed and underwent repeat anterior cervical discectomy and fusion (ACDF) or posterior decompression and fusion (PDF). Clinical outcomes (JOA, NDI, and VAS scores), perioperative parameters (blood loss, operation time, and length of hospital stay), radiological parameters (cervical lordosis and ROM), and complications were compared. RESULTS: Eighteen patients underwent ACDF, and 14 patients underwent PDF. Patients who underwent PDF were older, more frequently presented with myelopathic deficits, and were fused at more levels. Patients who underwent ACDF experienced significantly shorter surgery time (p < 0.001), lower blood loss (p < 0.001), and reduced hospital stay (p = 0.002). Both groups exhibited significant increases in JOA scores and decreases in NDI and both neck pain and arm pain VAS scores (p < 0.05), but patients who underwent PDF had significantly higher NDI scores (p = 0.012), neck pain VAS scores (p = 0.019), loss of cervical lordosis (p < 0.001), and loss of ROM (p = 0.001). Three patients developed dysphagia in the ACDF group, and two patients had C5 root palsy and one had hematoma in the PDF group. Recurrent ASD after the second operation occurred in two patients in the ACDF group but no patients in the PDF group. CONCLUSIONS: For patients with two-level symptomatic ASD, both anterior and posterior decompression and fusion were effective for improving the neurological function. For patients with radicular symptoms, ACDF had less surgical trauma, better restoration of lordosis, and less postoperative neck pain, but higher chance of recurrent ASD. PDF was an effective surgical option for older patients with myelopathy developing in adjacent segments.

Limited correction of lumbar lordosis in the treatment of degenerative scoliosis.

BACKGROUND: Patients suffering from degenerative scoliosis (DS) were commonly associated with coronal and sagittal imbalance which made deformity correction surgery necessary. The study aimed to explore the efficacy and feasibility of the limited correction of lumbar lordosis (LL) in the treatment of patients with DS. METHODS: This was a retrospective study including 58 DS patients who underwent spinal deformity correction surgery and were followed up at least 2 years between January 2013 and January 2017. According to the difference of postoperative LL, the patients were divided into 2 groups: the limited correction group: Pelvic incidence(PI)-18°≤ LL .05). In terms of surgery, the limited group had less intra-operative blood loss and operation time (P < .05). At the last follow-up, significant differences were found in terms of LL(-38.2 ±â€Š4.7° and -46.9 ±â€Š4.7°), PT (18.8 ±â€Š5.2° and 11.1 ±â€Š3.6°), sacrum slope (33.7 ±â€Š7.0° and 41.4 ±â€Š6.1°) (P < .05), while there were no significant differences in terms of lumbar Cobb angle (10.5 ±â€Š9.3°and 8.3 ±â€Š6.7°), Oswestry Disability Index scores (25.6 ±â€Š10.2 and 26.4 ±â€Š12.1), and JOA scores (23.6 ±â€Š5.2 and 22.3 ±â€Š5.7) (P > .05). CONCLUSION: Limited correction of LL in the treatment of DS patients can achieve favorable clinical outcomes including effective Cobb angle correction with less blood loss and operative time.

Analysis of the Change Patterns of Sagittal Alignment Values After Selective Thoracic Fusion in Lenke 1 Adolescent Idiopathic Scoliosis According to Preoperative Thoracic Kyphosis Status.

STUDY DESIGN: This was a retrospective study. OBJECTIVE: The objective of this study was to demonstrate the different change patterns in reciprocal sagittal alignment values after selective thoracic fusion (STF) in Lenke type 1 adolescent idiopathic scoliosis (AIS) according to preoperative thoracic kyphosis (TK). SUMMARY OF BACKGROUND DATA: Several studies have found significant increase in TK after STF, while other studies have reported decrease in TK postoperatively. Similar inconclusive results on changes in lumbar lordosis (LL) have been reported, showing LL increase, decrease, or no change. MATERIALS AND METHODS: Ninety-three patients presenting with Lenke type 1 AIS treated by posterior STF with a minimum follow-up of 2 years were included in this study. Using whole spine radiographs, sagittal parameters including TK, LL, and upper lumbar lordosis (ULL) were compared preoperatively and at the last follow-up between a hypokyphosis group (preoperative TK<20 degrees) and a normokyphosis group (preoperative TK≥20 degrees). Health-related quality of life (HRQOL) was assessed using scoliosis research society health-related quality of life-30 (SRS-30) and short from health survey-36 questionnaire at the last visit. RESULTS: The mean follow-up duration was 74.9 months. In the hypokyphosis group (35 patients), TK, LL, and ULL statistically significantly increased after surgery by mean 7.7, 5.1, and 3.7 degrees (P<0.001, <0.001, and 0.001). In the normokyphosis group (58 patients), these parameters did not show significant changes after STF. Final TK was significantly lower in hypokyphosis group than that in the normokyphosis group (21.2 vs. 30.9 degrees, P<0.001) while final LL did not differ between 2 groups (52.4 vs. 54.6 degrees, P=0.194). HRQOL did not differ significantly between the 2 groups. CONCLUSIONS: After STF in Lenke 1 AIS, TK, and LL statistically significantly increased through an increase in the mean ULL in the hypokyphosis group while those mean values did not change in the normokyphosis group. Despite the final mean value of the TK in the hypokyphosis group increasing by 7.7 degrees, it was statistically significantly lower than the final mean TK value in the normokyphosis group which did not increase after STF surgery by posterior approach. However, HRQOL showed no significant difference between the 2 groups.

Development of a novel geometrically-parametric patient-specific finite element model to investigate the effects of the lumbar lordosis angle on fusion surgery.

The success of lumbar interbody fusion, the key surgical procedure for treating different pathologies of the lumbar spine, is highly dependent on determining the patient-specific lumbar lordosis (LL) and restoring sagittal balance. This study aimed to (1) develop a personalized finite element (FE) model that automatically updates spinal geometry for different patients; and (2) apply this technique to study the influence of LL on post-fusion spinal biomechanics. Using an X-Ray image-based algorithm, the geometry of the lumbar spine (L1-S1) was updated using independent parameters. Ten subject-specific nonlinear osteoligamentous FE models were developed based on pre-operative images of fusion surgery candidate patients. Post-operative FE models of the same patients were consequently created. Comparison of the obtained results from FE models with pre- and post-operation functional images demonstrated the potential value of this technique in clinical applications. A parametric study of the effect of LL was conducted for cases with zero LL angle, positive LL angles (+6° and +12°) and negative LL angles (-3° and -6°) on fused level (L4-L5), resulting in a total of 50 fusion simulation models. The average range of motion, intradiscal pressure, and fiber strain at adjacent levels were significantly higher with decreased LL during different directions except axial rotation. This study demonstrates that the LL alters both the intersegmental motion and load-sharing in fusion, which may influence the initiation and rate of adjacent level degeneration. This personalized FE platform provides a practical, clinically applicable approach for the analyses of the biomechanical changes associated with lumbar spine fusion.

Is Anterior Bone Loss the Opposite of Anterior Heterotopic Ossification in Prestige-LP Cervical Disc Replacement?

BACKGROUND: Heterotopic ossification (HO) and anterior bone loss (ABL) are 2 complications in cervical disc replacement (CDR), which have impacts on the clinical outcomes. Physiologically, bone formation (HO) and bone loss are 2 sides of bone remodeling. However, clinically, some patients experienced anterior HO (AHO) after CDR, whereas other patients experienced ABL. Is there any factor in determining the fate of the vertebral bone in the anterior region? Is ABL the opposite of AHO? This study aims to answer these questions. METHODS: Seventy patients with 1-level Prestige-LP CDR were retrospectively reviewed and were divided into an AHO group or ABL group. Radiologic outcomes, including cervical lordosis, sagittal vertical axis, functional spine unit angle, disc angle, range of motion, implant migration, subsidence, and adjacent segment degeneration were evaluated. Patient-reported clinical outcomes were also evaluated. RESULTS: AHO group showed significantly lower disc angle after surgery (0.9° ± 4.2°), compared with ABL group (6.7° ± 4.7°) (P < 0.001). The preoperative segmental range of motion was significantly higher in the AHO group (10.2° ± 3.3°) than in the ABL group (8.2° ± 3.7°) (P = 0.042). No correlation was observed between clinical outcomes and the presence of anterior bone remodeling. Both groups maintained cervical alignment and functional spine unit angle during long-term follow-up. No significant difference was found in the end plate preparation, implant subsidence, migration, or adjacent segment degeneration rate between the 2 groups. CONCLUSIONS: The differences in the disc angle showed the role of mechanical load in the anterior bone remodeling. Combined the results with the basic concepts of bone remodeling, ABL may be the opposite of AHO.

The Correlation of Spinopelvic Parameters With Biomechanical Parameters Measured by Gait and Balance Analyses in Patients With Adult Degenerative Scoliosis.

STUDY DESIGN: A prospective cohort study. OBJECTIVE: The objective of this study was to establish the correlation between radiographic spinopelvic parameters with objective biomechanical measures of function in patients with adult degenerative scoliosis (ADS). SUMMARY OF BACKGROUND DATA: Gait and balance analyses can provide an objective measure of function. Patients with ADS demonstrate altered gait and balance patterns. Spinopelvic parameters are commonly used by clinicians to evaluate patients with ADS. However, to the best of our knowledge, no studies have examined the correlation between patients' radiographic spinopelvic parameters and biomechanical gait and balance parameters. PATIENT SAMPLE: Forty-four patients with symptomatic ADS who have been deemed, appropriate surgical candidates. METHODS: Radiographic spinopelvic parameters (CVA: central vertical axis, SVA: sagittal vertical axis, Cobb angle, PI-LL mismatch: pelvic incidence lumbar lordosis mismatch, and T1PA: T1 pelvic angle) were obtained the week before surgery. Then, gait and functional balance analyses (spatiotemporal parameters, center of mass, and head sway parameters) were performed on the same day. Correlations were determined between the radiographic spinopelvic parameters and biomechanical gait and balance parameters using Pearson product correlation. RESULTS: Our results show that patients with higher Cobb angle and CVA tend to walk slower (r=-0.494, P<0.05). Furthermore, the higher the Cobb angle (r=0.396), CVA (r=0.412), SVA (r=0.440), and PI-LL mismatch (r=0.493), the more time ADS patients spend with their feet planted during single and double support phases of gait (P<0.05). In addition, patients with a higher Cobb angle, CVA, SVA, PI-LL mismatch, and T1PA, exhibited more trunk sway, increased lower extremity neuromuscular activity, and decreased spine neuromuscular activity (0.331

Spinopelvic alignment does not change after bilateral total hip arthroplasty in patients with bilateral Crowe type-IV developmental dysplasia of the hip.

OBJECTIVE: This prospective study aimed to evaluate the changes in the sagittal alignment after total hip arthroplasty (THA) in patients with hip osteoarthritis (OA) secondary to Crowe type-IV developmental dysplasia of the hip (DDH) and whether THA would contribute to the relief of low-back pain (LBP). METHODS: A total of 27 patients (2 men and 25 women) with bilateral hip OA secondary to Crowe type-IV DDH were enrolled in this study. Their mean age at the time of surgery was 40,36±12,35. All patients underwent simultaneous, bilateral THA between January 2015 and December 2016. Clinical assessment included Oswestry disability index (ODI) score and Harris hip score (HHS), and pelvic incidence (PI), sacral slope (SS), lumbar lordosis (LL), and pelvic tilt (PT) were measured from radiographs. RESULTS: Preoperatively, all the patients had hip and low-back pain. Preoperative and final follow-up ODI scores were 48.3 and 3.9 (p=0.000), respectively. HHS changed from 43.54 to 92.68 (p=0.000). PT and PI significantly changed from -20.4°±20.4° to 3.2°±16.7° (p=0.001) and from 26.6°±35.1° to 47.4°±17.9° (p=0.001), respectively. There were no significant differences regarding the SS and LL measurements. Age or limb-length discrepancy was not significantly associated with the spinopelvic alignment measurements. CONCLUSION: Restoring the function of the hip with THA is shown to improve hip-associated LBP, but the accompanying hyperlordosis does not change. THA in patients with bilateral Crowe type-IV hips relieves hip pain as well as associated LBP. Hyperlordosis of the lumbar vertebra does not change after surgery, but PI and PT changes are observed; this improvement might have a role in the relief of LBP. LEVEL OF EVIDENCE: Level IV, Therapeutic study.

Assessment of anterior-posterior spinal curvatures in children suffering from hypopituitarism.

BACKGROUND: Body posture may be disordered by vestibular dysfunction, neurological disorders, problems with the distribution of muscle tone, brain injuries, and other dysfunctions. Growth hormone deficiency (GHD) can lead to many disorders, particularly of the musculoskeletal system. During treatment with recombinant human growth hormone (rhGH), an increase in muscle mass and an improvement in bone structure can be observed in children suffering from hypopituitarism from GHD. METHODS: The study involved 33 children suffering from hypopituitarism with GHD (9 girls and 24 boys), aged 10-14 years old. Measurements of the magnitude of their anterior-posterior spinal curvatures were made using an inclinometer. The children were examined at the medianus of the sacrum bone, the Th12-L1 intervertebral area, and the C7-Th1 intervertebral area. In order to characterize the anterior-posterior curvature of the spine, the results were compared with the general norms reported by Saunders. Statistical calculations were carried out using the statistical package Statistica 10 PL. RESULTS: Lumbar lordosis angles were higher in the patients currently receiving growth hormone (GH) treatment than in those who had yet to receive it. There is a statistically significant positive correlation between the length of growth hormone treatment and the alpha angle. There are also statistically significant correlations between age at the beginning of growth hormone therapy and the angle of lordosis. Statistically significant correlations were also seen between age at the beginning of growth hormone therapy and the alpha angle. CONCLUSIONS: Although there may be changes in posture at the beginning of rhGH treatment, the sooner growth hormone therapy begins, the better the body posture. The longer the growth hormone treatment, the better the posture, as expressed by the alpha angle in the sagittal plane.

Global sagittal spinal alignment in patients with degenerative low-grade lumbar spondylolisthesis.

PURPOSE: Global sagittal spinal alignment undergoes changes on the basis of sagittal malalignment (trunk inclined forward) in natural degenerative progression. We hypothesized that this change would associate with the disease state of the degenerative lumbar spondylolisthesis (DS). This study aimed to evaluate the global sagittal spinal alignment of low-grade DS by classifying in accordance with sagittal vertical axis (SVA). METHODS: The DS group was classified into three types according to the adult spinal deformity classification: type 1, SVA < 40 mm; type 2, 40 mm ≤ SVA < 95 mm; and type 3, 95 mm ≤ SVA. Age and sagittal spinal parameters (thoracic kyphosis, lumbar lordosis (LL), sacral slope (SS), pelvic tilt (PT), and pelvic incidence (PI)) were compared among three types. RESULTS: There were statistically significant differences in age, LL, PI, and PT among the three types. In comparison between two types, there was a statistically significant difference between type 1 and type 2 and between type 1 and type 3, but not between type 2 and type 3 in these parameters. PI tended to increase as the type increases. Furthermore, there was significant difference between types 1 and 3. CONCLUSION: We evaluated the features of the DS types classified by sagittal alignment. Large PI is one of the risk factors for SVA deterioration of DS. PI may be involved in the onset and progression of DS.

Protein kinase inhibitors infused intraventricularly or into the ventromedial hypothalamus block short latency facilitation of lordosis by oestradiol.

An injection of unesterified oestradiol (E2 ) facilitates receptive behaviour in E2 benzoate (EB)-primed, ovariectomised female rats when it is administered i.c.v. or systemically. The present study tested the hypothesis that inhibitors of protein kinase A (PKA), protein kinase G (PKG) or the Src/mitogen-activated protein kinase (MAPK) complex interfere with E2 facilitation of receptive behaviour. In Experiment 1, lordosis induced by i.c.v. infusion of E2 was significantly reduced by i.c.v. administration of Rp-cAMPS, a PKA inhibitor, KT5823, a PKG inhibitor, and PP2 and PD98059, Src and MAPK inhibitors, respectively, between 30 and 240 minutes after infusion. In Experiment 2, we determined whether the ventromedial hypothalamus (VMH) is one of the neural sites at which those intracellular pathways participate in lordosis behaviour induced by E2 . Administration of each of the four protein kinase inhibitors into the VMH blocked facilitation of lordosis induced by infusion of E2 also into the VMH. These data support the hypothesis that activation of several protein kinase pathways is involved in the facilitation of lordosis by E2 in EB-primed rats.

Effect of intraoperative position in single-level transforaminal lumbar interbody fusion at the L4/5 level on segmental and overall lumbar lordosis in patients with lumbar degenerative disease.

The purpose of this study was to investigate the effect of intraoperative positions in single-level (L4-5) transforaminal lumbar interbody fusion (TLIF) on segmental and overall lumbar lordosis (LL) in patients with lumbar degenerative disease. Thirty-eight consecutive patients who had undergone single-segment (L4-5) TLIF with 0° polyetheretherketone (PEEK) cage and pedicle screw fixation were evaluated. Twenty patients underwent surgery on the four-poster type frame with hip flexion at 30° (Group I) and 18 patients were operated on a Jackson spinal table to adjust their hip flexion to 0° (Group II). Preoperative standing, intraoperative prone, and postoperative standing lateral radiographs were obtained in each patient. The overall and segmental LL were analyzed according to the position in which the patients were placed for their operation and results compared between Groups I and II. Intraoperative intervertebral segmental LL at L4-5 and L5-S1 was increased in Group II than in Group I, whereas postoperative intervertebral segmental LL at L4-5 (fused level) was increased LL. In Group I intraoperative intervertebral segmental LL at L4-5 did not achieve sufficient lordosis, whereas postoperative intervertebral segmental LL at L3-4 was increased. The overall spinal alignment was unaffected by the decreased segmental LL in the fused level owing to the compensation of the upper adjacent segments. The more the hip was extended intraoperatively, the more the segmental lordosis increased in the lower lumbar spine. Thus, selecting the appropriate surgical table and hip position are very important. Underachievement of segmental lordosis leads to the acceleration of upper adjacent segment load.

Association between sagittal balance and adjacent segment degeneration in anterior cervical surgery: a systematic review and meta-analysis.

BACKGROUND: ASD is a relatively common degenerative alteration after cervical surgery which occurs above or below the fused segment. In addition, some patients may need reoperation to treat severe ASD after the primary surgery. It was considered that sagittal balance is correlated with postoperative clinical outcomes; however, few studies have reported the influence of sagittal balance on ASD. The present study is designed to investigate whether sagittal balance impacts the pathology of adjacent segment disease (ASD) in patients who undergo anterior cervical surgery for degenerative cervical disease. METHODS: Databases including Pubmed, Embase, Cochrane library, and Web of Science were used to search for literature published before June 2018. Review Manager 5.3 was used to perform the statistical analysis. Sagittal balance parameters before and after surgery were compared between patients with and without ASD. Weighted mean difference (WMD) was summarized for continuous data and P < 0.05 was set for the level of significance. RESULTS: A total of 221 patients with ASD and 680 patients without ASD from seven articles were studied in this meta-analysis. There were no significant differences in most sagittal balance parameters between the two groups, except for postoperative cervical lordosis (CL) (WMD -3.30, CI -5.91, - 0.69, P = 0.01). CONCLUSIONS: Some sagittal balance parameters may be associated with the development of ASD after anterior cervical surgery. Sufficient restoration of CL may decrease the incidence of ASD. The results in present study needed to be expanded carefully and further high-quality studies are warranted to investigate the impact of sagittal balance on ASD.

Sagittal balance of the spine.

The static sagittal balance of the normal spine is a physiological alignment of the spine in the most efficient manner by the muscular forces. During gait, this balance is constantly thwarted by single-foot support. This analysis involves the study of parameters which are now well defined. The pelvic incidence is constant, and the sacral slope and the pelvic tilt are positional. The cervical parameters are the upper (O-C2) and lower cervical curvatures (C2-C7), the C7 slope, the spino-cranial angle and the vertical cervical offset. At the thoracic and lumbar level, they are, respectively, kyphosis and lordosis. The OD-HA (odontoid hip axis) angle is the most efficient parameter to analyse the global balance. The average values of these parameters are reported with the new 3D measurements by Le Huec et al. The relationship between these different parameters was analysed, and Roussouly proposed his classification of the different spine shape. Ageing makes it possible to show compensation mechanisms at three levels: spinal, pelvic and lower limbs. Understanding these different data allows for better planning of the surgical management of the patients. Global evaluation of the entire spine and the measurement of the aforementioned parameters allow to determine the extent of the correction to be performed during surgery. Taking these parameters into account also enables us to understand the complications involved in this type of surgery: transitional syndromes or junctional syndromes. Integration of these parameters into the study of gait is an area still under investigation. These slides can be retrieved under Electronic Supplementary Material .

Failure of Pelvic Compensation in Patients With Severe Positive Sagittal Imbalance: Comparison Between Static Radiographs and Gait Analysis of Spinopelvic Parameters in Adult Spinal Deformity and Lumbar Stenosis.

STUDY DESIGN: Case-control study for motion analysis. OBJECTIVE: To compare spinopelvic parameters using static radiographs with the values obtained using motion analysis during gait between adult spinal deformity (ASD) or lumbar spinal stenosis (LSS). SUMMARY OF BACKGROUND DATA: It is still unclear whether measurement of radiological parameters using static radiographs can reflect natural sagittal balance during gait in the patients with severe positive sagittal imbalance. METHODS: In this age- and sex-matched case control study, a total of 40 patients, each 20 subjects with either ASD or LSS who were scheduled to undergo surgery were included. Both clinical outcomes and sagittal spinopelvic parameters, including sagittal vertical axis (SVA), lumbar lordosis (LL), pelvic tilt (PT), sacral slope (SS), and pelvic incidence (PI) were measured. In motion analysis during walking, the angle of anterior pelvic tilt and the angles of the pelvis, hip, and knee were estimated. The correlation between variables was analyzed. RESULTS: On standing lateral x-rays, SVA, PT, and PI - LL were significantly higher in the ASD group while SS and LL were significantly lower in the ASD group. However, on motion analysis, the average mean anterior pelvic tilt ±â€ŠSD values in the ASD group were 8.3 ±â€Š10.7 and 8.5 ±â€Š10.7 on the right and left, respectively, and were not different from matched values in the LSS group. A Bland-Altman plot demonstrated a good agreement between the SS in the x-ray and anterior pelvic tilt in the motion analysis. In the ASD group, SS and SVA showed a significant positive correlation with mean anterior pelvic tilt in motion analysis during gait. CONCLUSION: The present study showed that the failure of pelvic compensation would likely occur in patients with severe positive sagittal imbalance during walking. LEVEL OF EVIDENCE: 3.

Correlations linking static quantitative gait analysis parameters to radiographic parameters in adolescent idiopathic scoliosis.

BACKGROUND: Radiography is the main tool used to assess spinal deformities in patients with adolescent idiopathic scoliosis (AIS) but requires repeated exposure to ionising radiation, potentially raising safety concerns. Consequently, new methods are needed. Among them, the acquisition of static parameters during quantitative gait analysis (QGA) has received attention in recent years. However, no data on correlations linking static QGA parameters to standard radiographic parameters are available. The objective of this study was to assess correlations between static QGA parameters and standard radiographic parameters in patients with AIS. HYPOTHESIS: Spinal deformities in patients with AIS can be evaluated based on static QGA parameters. PATIENTS AND METHODS: We studied patients scheduled for surgery to treat AIS. On the day before surgery, QGA was performed and antero-posterior and lateral radiographs obtained. QGA involved analysing the positions of 32 reflective markers, including 6 used to assess the spine. The coronal vertical axis (CVA), thoracic and lumbar Cobb angles, sagittal vertical axis (SVA), thoracic kyphosis, lumbar lordosis, and pelvic tilt were recorded and compared to the corresponding radiographic parameters. RESULTS: The study included 57 patients, including 48 (84%) females, with a mean age of 15.2 years. Among them, 45 had Lenke 1 and 12 Lenke 5 scoliosis. The mean main Cobb angle was 51.9°. In the coronal plane, significant correlations with the corresponding radiographic parameters were found for the CVA (R=0.524, p<0.01) and thoracic Cobb angle (R=0.599, p<0.01). All the sagittal parameters correlated significantly with the corresponding radiographic parameters: SVA, R=0.313; pelvic tilt, R=0.342; thoracic kyphosis, R=0.575; and lumbar lordosis, R=0.360 (p<0.05 for all four parameters). CONCLUSIONS: In this study, static QGA parameters accurately reflected the spinal deformities visualised radiographically. The lumbar deformity was more difficult to characterise, probably because it was mild in our population. Research efforts should focus on improving the performance of QGA, notably for detecting curve progression. Thus, QGA may allow a decrease in radiation exposure of patients with AIS. LEVEL OF EVIDENCE: III.