Current biomechanical theories on the etiopathogenesis of idiopathic scoliosis

PURPOSE

There is great controversy about the etiologic origin of adolescent idiopathic scoliosis. Multiple theories have been suggested, including metabolic aspects, endocrine dysfunction, neurological central abnormalities, genetic predisposition and epigenetic factors involved in the development of scoliosis. However, there has always been speculations based on human biomechanical behavior.

METHODS

In this article, we performed a literature review on the biomechanical traits of human posture, and the proposed theories that explain the special characteristics present in idiopathic scoliosis.

RESULTS

The current theory on the etiopathogeneis of AIS suggests that dorsally directed shear loads acting on a preexisting axial plane rotation, in a posteriorly inclined sagittal plane of a growing patient, together with disc maturation, collagen quality at this phase of development and immaturity of proprioception, is the perfect scenario to spark rotational instability and create the three-dimensional deformity that defines idiopathic scoliosis.

CONCLUSION

The unique spinal alignment of human bipedalism, gravity and muscle forces acting straight above the pelvis to preserve an upright balance, and the instability of the soft tissue in a period of growth development, is an appealing cocktail to try to explain the genesis of this condition in humans.

Quantifying Muscle Size Asymmetry in Adolescent Idiopathic Scoliosis Using Three-dimensional Magnetic Resonance Imaging

STUDY DESIGN

This is a case-control study of prospectively collected data.

OBJECTIVE

To quantify paraspinal muscle size asymmetry in adolescent idiopathic scoliosis (AIS) and determine if this asymmetry is (i) greater than observed in adolescent controls with symmetrical spines; and (ii) positively associated with skeletal maturity using Risser grade, scoliosis severity using the Cobb angle, and chronological age in years.

SUMMARY OF BACKGROUND DATA

AIS is a three-dimensional deformity of the spine which occurs in 2.5% to 3.7% of the Australian population. There is some evidence of asymmetry in paraspinal muscle activation and morphology in AIS. Asymmetric paraspinal muscle forces may facilitate asymmetric vertebral growth during adolescence.

METHODS

An asymmetry index [Ln(concave/convex volume)] of deep and superficial paraspinal muscle volumes, at the level of the major curve apex (Thoracic 8-9 th vertebral level) and lower-end vertebrae ( LEV , Thoracic 10-12 th vertebral level), was determined from three-dimensional Magnetic Resonance Imaging of 25 adolescents with AIS (all right thoracic curves), and 22 healthy controls (convex=left); all female, 10 to 16 years.

RESULTS

Asymmetry index of deep paraspinal muscle volumes was greater in AIS (0.16±0.20) than healthy spine controls (-0.06±0.13) at the level of the apex ( P <0.01, linear mixed-effects analysis) but not LEV ( P >0.05). Asymmetry index was positively correlated with Risser grade ( r =0.50, P <0.05) and scoliosis Cobb angle ( r =0.45, P <0.05), but not age ( r =0.34, P >0.05). There was no difference in the asymmetry index of superficial paraspinal muscle volumes between AIS and controls ( P >0.05).

CONCLUSIONS

The asymmetry of deep apical paraspinal muscle volume in AIS at the scoliosis apex is greater than that observed at equivalent vertebral levels in controls and may play a role in the pathogenesis of AIS.

Quantifying Typical Progression of Adolescent Idiopathic Scoliosis: Longitudinal Three-Dimensional MRI Measures of Disk and Vertebral Deformities

STUDY DESIGN

A prospective cohort study.

OBJECTIVE

Detail typical three-dimensional segmental deformities and their rates of change that occur within developing adolescent idiopathic scoliosis (AIS) spines over multiple timepoints.

SUMMARY OF BACKGROUND DATA

AIS is a potentially progressive deforming condition that occurs in three dimensions of the scoliotic spine during periods of growth. However, there remains a gap for multiple timepoint segmental deformity analysis in AIS cohorts during development.

MATERIALS AND METHODS

Thirty-six female patients with Lenke 1 AIS curves underwent two to six sequential magnetic resonance images. Scans were reformatted to produce images in orthogonal dimensions. Wedging angles and rotatory values were measured for segmental elements within the major curve. Two-tailed, paired t tests compared morphologic differences between sequential scans. Rates of change were calculated for variables given the actual time between successive scans. Pearson correlation coefficients were determined for multidimensional deformity measurements.

RESULTS

Vertebral bodies were typically coronally convexly wedged, locally lordotic, convexly axially rotated, and demonstrated evidence of local mechanical torsion. Between the first and final scans, apical measures of coronal wedging and axial rotation were all greater in both vertebral and intervertebral disk morphology than nonapical regions (all reaching differences where P <0.05). No measures of sagittal deformity demonstrated a statistically significant change between scans. Cross-planar correlations were predominantly apparent between coronal and axial planes, with sagittal plane parameters rarely correlating across dimensions. Rates of segmental deformity changes between earlier scans were characterized by coronal plane convex wedging and convexly directed axial rotation. The major locally lordotic deformity changes that did occur in the sagittal plane were static between scans.

CONCLUSIONS

This novel investigation documented a three-dimensional characterization of segmental elements of the growing AIS spine and reported these changes across multiple timepoints. Segmental elements are typically deformed from initial presentation, and subsequent changes occur in separate orthogonal planes at unique times.

MRI-based measurements of spondylolisthesis and kyphosis in degenerative cervical myelopathy

BACKGROUND

To provide normative data and to determine accuracy and reliability of preoperative measurements of spondylolisthesis and kyphosis on supine static magnetic resonance imaging (MRI) of patients with degenerative cervical myelopathy.

METHODS

T2-weighted midsagittal images of the cervical spine were in 100 cases reviewed twice by one junior observer, with an interval of 3 months, and once by a senior observer. The spondylolisthesis slip (SSlip, mm) and the modified K-line interval (mK-line INT, mm) were assessed for accuracy with the standard error of measurement (SEm) and the minimum detectable change (MDC). Intraobserver and interobserver reliability levels were determined using the intraclass correlation coefficient (ICC).

RESULTS

The SEm was 0.5 mm (95% CI 0.4-0.6) for spondylolisthesis and 0.6 mm (95% CI 0.5-0.7) for kyphosis. The MDC, i.e., the smallest difference between two examinations that can be detected with statistical certainty, was 1.5 mm (95% CI 1.2-1.8) for spondylolisthesis and 1.6 mm (95% CI 1.3-1.8) for kyphosis. The highest reliability levels were seen between the second observation of the junior examiner and the senior observer (ICC = 0.80 [95% CI 0.70-0.87] and ICC = 0.96 [95% CI 0.94-0.98] for SSlip and mK-line INT, respectively).

CONCLUSIONS

This study provides normative values of alignment measurements of spondylolisthesis and kyphosis in DCM patients. It further shows the importance of taking measurement errors into account when defining cut-off values for cervical deformity parameters and their potential clinical application in surgical decision-making.

Calcium sensing and signaling are impaired in the lumbar spine of a rat model of congenital kyphosis

PURPOSE

Kyphosis involves spines curving excessively backward beyond their physiological curvature. Although the normal structure of the spinal vertebrae is extremely important for maintaining posture and the normal function of the thoracic and abdominal organs, our knowledge concerning the pathogenesis of the disease is insufficient. We herein report that the downregulation of the calcium signaling pathway is involved in the pathogenesis of congenital kyphosis.

METHODS

The third to fifth lumbar spine segments, the kyphotic region of Ishibashi (IS) rats, which are used as a model of congenital kyphoscoliosis, were collected. A DNA microarray, quantitative PCR, Western blotting, and immunohistochemistry were used to measure the expression of genes and proteins related to intracellular calcium signaling.

RESULTS

We found that the expression of calcium-sensing receptor (CaSR) and transient receptor potential vanilloid 1 (Trpv1)-two receptors involved in the calcium signaling-was decreased in the lumbar spine of IS rats. We also observed that the number of CaSR-immunoreactive and Trpv1-immunoreactive cells in the lumbar spine of IS rats was lower than in wild-type rats. Furthermore, the expression of intracellular molecules downstream of these receptors, such as phosphorylated protein kinase C, c-Jun N-terminal kinase, and neural EGFL-like 1, was also reduced. In fact, the calcium content in the lumbar spine of IS rats was significantly lower than that in wild-type rats.

CONCLUSION

These results indicate that adequate calcium signaling is extremely important for the regulation of normal bone formation and may also be a key factor for understanding the pathogenesis of congenital kyphosis.

MRI features of spinal chronic recurrent multifocal osteomyelitis/chronic non-bacterial osteomyelitis in children

BACKGROUND

Spinal lesions in pediatric chronic recurrent multifocal osteomyelitis/chronic non-bacterial osteomyelitis (CRMO/CNO) can cause permanent sequelae; thus, early recognition of these is vital for management.

OBJECTIVE

To characterize the MR imaging features and patterns of pediatric spinal CRMO/CNO.

MATERIALS AND METHODS

This cross-section study received IRB approval. The first available MRI with documented spine involvement in children with CRMO/CNO was reviewed by a pediatric radiologist. Descriptive statistics were used to describe the characteristics of vertebral lesions, disc involvement, and soft tissue abnormality.

RESULTS

Forty-two patients were included (F:M, 30:12); median age was 10 years (range 4-17). At diagnosis, 34/42 (81%) had spine involvement. Kyphosis in 9/42 (21%) and scoliosis in 4/42 (9.5%) patients were present at the time of spinal disease recognition. Vertebral involvement was multifocal in 25/42 (59.5%). Disc involvement was found in 11/42 (26%) patients, commonly in the thoracic spine and often with adjacent vertebrae height loss. Posterior element abnormalities were present in 18/42 patients (43%) and soft tissue involvement in 7/42 (17%). One hundred nineteen vertebrae were affected, commonly the thoracic vertebrae (69/119; 58%). Vertebral body edema was focal in 77/119 (65%) and frequently superior (42/77; 54%). Sclerosis and endplate abnormality were present in 15/119 (13%) and 31/119 (26%) vertebrae, respectively. Height loss was present in 41/119 (34%).

CONCLUSION

Chronic non-bacterial osteomyelitis of spine is usually thoracic. Vertebral body edema is often focal at the superior vertebral body. Kyphosis and scoliosis occur in a quarter and vertebral height loss in a third of children at spinal disease recognition.

Preoperative Association Between Quantitative Lumbar Muscle Parameters and Spinal Sagittal Alignment in Lumbar Fusion Patients

STUDY DESIGN

A retrospective cross-sectional study.

OBJECTIVE

To assess the association between spinal muscle morphology and spinopelvic parameters in lumbar fusion patients, with a special emphasis on lumbar lordosis (LL).

SUMMARY OF BACKGROUND DATA

Maintenance of sagittal alignment relies on muscle forces, but the basic association between spinal muscles and spinopelvic parameters is poorly understood.

MATERIALS AND METHODS

Patients operated between 2014 and 2017 who had both lumbar magnetic resonance imaging scan and standing whole-spine radiographs within six months before surgery were included. Muscle measurements were conducted on axial T2-weighted magnetic resonance images at the superior endplate L3-L5 for the psoas and L3-S1 for combined multifidus and erector spinae (paraspinal) muscles. A pixel intensity threshold method was used to calculate the total cross-sectional area (TCSA) and the functional cross-sectional area (FCSA). Spinopelvic parameters were measured on lateral standing whole-spine radiographs and included LL, pelvic incidence (PI), PI-LL mismatch, pelvic tilt, sacral slope, thoracic kyphosis, and sagittal vertical axis. Analyses were stratified by biological sex. Multivariable linear regression analyses with adjustments for age and body mass index (BMI) were performed.

RESULTS

A total of 104 patients (62.5% female) were included in the analysis. The patient population was 90.4% White with a median age at surgery of 69 years and a median BMI of 27.8 kg/m 2 . All muscle measurements were significantly smaller in women. PI, pelvic tilt, and thoracic kyphosis were significantly greater in women. PI-LL mismatch was 6.1° (10.6°) in men and 10.2° (13.5°) in women ( P =0.106), and sagittal vertical axis was 45.3 (40.8) mm in men and 35.7 (40.8) mm in women ( P =0.251). After adjusting for age and BMI, paraspinal TCSA at L3-L5, and paraspinal FCSA at L4 showed significant positive associations with LL in women. In men, psoas TCSA at L5 and psoas FCSA at L5 showed significant negative associations with LL, but none of the paraspinal muscle measurements.

CONCLUSION

Our findings indicate that psoas and lumbar spine extensor muscles interact differently on LL among men and women, creating a unique mechanical environment.

LEVEL OF EVIDENCE

Level 4.

Two novel variants in PLOD1 causing hydrocephalus in female newborn with kyphoscoliotic Ehlers-Danlos syndrome

The kyphoscoliotic Ehlers-Danlos syndrome (kEDS) is a rare autosomal recessive connective tissue disorder characterized by hyperextensible skin and joints, kyphoscoliosis, and severe muscle hypotonia at birth. Causal variants have been identified in PLOD1 resulting in lysyl hydroxylase deficiency responsible for kEDS. However, the detailed phenotype of kEDS during the perinatal period is still poorly recognized. Here, we describe a case of a female newborn presenting with prenatal hydrocephalus and severe hypotonia after birth with two novel compound heterozygous variants, c.2T > C (p.?) and c.1462del (p. Arg488Glyfs*9) in the PLOD1 gene. Our case suggests that in addition to the reported phenotype during the neonatal period, prenatal hydrocephalus should also be differentially diagnosed to exclude the potential of kEDS.

Apoptosis of endplate chondrocytes in cervical kyphosis is associated with chronic forward flexed neck: an in vivo rat bipedal walking model

BACKGROUND

This study was undertaken to establish a rat bipedal walking model of cervical kyphosis (CK) associated with chronic forward flexed neck and assess the effects of chronic forward flexed neck on endplate chondrocytes.

METHODS

Forty-eight 1-month-old Sprague-Dawley rats were randomly divided into 3 groups: forward flexed neck group (n = 16), bipedal group (n = 16), and normal group (n = 16). Cervical curves were analyzed on a lateral cervical spine X-ray using Harrison's posterior tangent method before the experiment and at 2-week intervals for a 6-week period. Histologic changes in cartilaginous endplate chondrocytes were observed using hematoxylin and eosin (H&E) staining, transmission electron microscopy (TEM), and terminal deoxyribonucleotidyl transferase (TdT)-mediated dUTP nick-end labeling.

RESULTS

Radiographic findings suggested a significantly decreased cervical physiological curvature in the forward flexed neck group over the 6-week follow-up; normal cervical curves were maintained in other groups. The average cervical curvature (C2-C7) was - 7.6 ± 0.9° in the forward flexed neck group before the experiment, - 3.9 ± 0.8° at 2 weeks post-experiment, 10.7 ± 1.0° at 4 weeks post-experiment, and 20.5 ± 2.1° at the last follow-up post-experiment. Histologically, results of H&E staining unveiled that cartilaginous endplate chondrocytes were arranged in an irregular fashion, with the decreased number at the observation period; the incidence of apoptotic cells in the forward flexed neck group was noticeably higher at the 6-week follow-up than that in other groups.

CONCLUSIONS

CK developed as the result of chronic forward flexed neck. Histologic changes suggested that chondrocyte apoptosis may play a critical role in the development of cervical kyphotic deformity associated with chronic forward flexed neck.

Effect of sagittal shape on proximal junctional kyphosis following thoracopelvic corrective fusion for adult spinal deformity: postoperative inflection vertebra cranial to T12 is a significant risk factor

STUDY DESIGN

This was a retrospective analysis of a prospectively collected consecutive case series of patients with adult spinal deformity (ASD).

OBJECTIVE

This study aimed to investigate the impact of the geometrical sagittal shape of the corrected spine on the development of proximal junctional kyphosis (PJK). Several studies have documented risk factors for PJK in ASD surgery. Geometrical assessment is vital for evaluating sagittal spinal deformity. It is essential to assess the postoperative geometrical shape of the spine and the location of the correction in the spine to decrease postoperative junctional stress and PJK.

METHODS

Consecutive patients with ASD who underwent corrective fusion with long constructs to the pelvis were included. Patients with neuromuscular disease, congenital and adolescent scoliosis, infection, and spinal tumor were excluded. We investigated the spinopelvic and geometrical parameters of the whole spine. The locations of the thoracic and lumbar apical vertebrae and the inflection vertebrae (IV), where the curvature of the associated adjacent vertebral bodies changes from kyphosis to lordosis, were investigated. The subjects were divided into PJK included patients who underwent revision surgery for junctional failure or with a change in proximal junctional angle ≥ 20°, and non-PJK groups.

RESULTS

A total of 139 patients (mean age, 69.6 years; range 18-82 years) were included. There were 47 and 92 patients in the PJK and non-PJK groups, respectively. The IV were located significantly cranial and posterior, the lumbar apex were located significantly posterior in the PJK group at the immediate postoperative time points. The significant risk factors for PJK on binary logistic regression were cranial IV and posterior lumbar apical vertebrae. The incidence of PJK in patients with IV at T12 or cranial tends PJK significantly higher (69%) than at L1 or caudal (26%).

CONCLUSIONS

Geometrical spinal shape should be taken into account to reduce the rate of postoperative mechanical complications.

LEVEL OF EVIDENCE

Level of evidence III.

Upregulated miR-224-5p suppresses osteoblast differentiation by increasing the expression of Pai-1 in the lumbar spine of a rat model of congenital kyphoscoliosis

Congenital scoliosis is defined by the presence of structural anatomical malformations that arise from failures of vertebral formation or segmentation before and after birth. The understanding of genetic background and key genes for congenital scoliosis is still poor. We herein report that the excess expression of plasminogen activator inhibitor-1 (Pai-1) induced by the upregulation of miR-224-5p is involved in the pathogenesis of congenital kyphoscoliosis through impaired osteoblast differentiation. We first investigated the variety and progression of abnormalities of the lumbar spines in Ishibashi (IS) rats, a rat model of congenital kyphoscoliosis. The rats had already shown fusion and division of the primary ossification center at postnatal day 4. Over time, the rats showed various abnormalities of the lumbar spine, including the fusion of the annular epiphyseal nucleus. At postnatal day 42, spinal curvature was clearly observed due to the fusion of the vertebral bodies. Using a microRNA array, we found that the expression of miR-224-5p was increased in the lumbar spine of the rats at postnatal day 4. The expression of Pai-1, which is involved in osteoblast differentiation regulated by miR-224-5p, was also increased, while the levels of type I collagen, a marker of osteoblast differentiation, were decreased in the lumbar spine. These results indicate that the aberrant expression of miRNA-224-5p and its target genes is involved in the impaired osteoblast differentiation and may provide a partial molecular explanation for the pathogenesis of congenital scoliosis.

The Link Between the 3D Spino-pelvic Alignment and Vertebral Body morphology in Adolescent Idiopathic Scoliosis

BACKGROUND

Vertebral anterior overgrowth has been suggested as part of the etio-pathogenesis of adolescent idiopathic scoliosis (AIS). However, the link between 3D spinopelvic alignment and the vertebral anteroposterior height asymmetry in different scoliotic curves types and whether it deviates from the non-scoliotic controls, has not been studied.

PURPOSE

We aimed to retrospectively describe the link between the anteroposterior vertebral height differences (ΔAPVH) measured in the true sagittal plane of each vertebra and the spinopelvic parameters in three anatomical planes.

METHODS

30 AIS cases with primary thoracic curves, 28 with thoracolumbar/lumbar curves, and 20 non-scoliotic controls were included. All subjects had 3D reconstruction of the spine, generated from low-dose upright stereoradiography images. Pelvic incidence (PI), thoracic and lumbar coronal and sagittal curve measurements, and vertebral axial rotation were measured. The association between the spinopelvic parameters and ΔAPVH were compared between the two AIS and control groups.

RESULTS

ΔAPVH at the apex of the curve was significantly different between the two AIS groups, as well as between both AIS groups and the controls and was related to the vertebral apical rotation (p < 0.05). Kyphosis and lordosis measurements were significantly related to the sum of the ΔAPVH in thoracic and lumbar regions respectively in AIS group but not in non-scoliotic controls (p < 0.05).

CONCLUSIONS

The ΔAPVH depended on the scoliotic curve type and was significantly different from the controls only at the apical levels. Morphological changes in the scoliotic vertebrae, measured as anterior-posterior differences in the vertebral height, are related to the sagittal spinal profile suggesting the morphology of the vertebra contributes to the sagittal curvatures of the spine in AIS; nonetheless, such relationship between the vertebral morphology and the sagittal profile was not evident in non-scoliotic controls.

A Classification for Kyphosis Based on Column Deficiency, Curve Magnitude, and Osteotomy Requirement

BACKGROUND

There is a lack of a classification system providing uniformity in description and guiding management decisions for kyphotic spinal deformities. We developed such a classification based on column deficiency, flexibility of disc spaces, curve magnitude, and correlation with the corrective osteotomy required.

METHODS

A classification was developed based on analysis of 180 patients with thoracolumbar kyphosis requiring osteotomy. The deformity was classified as Type I if the anterior and posterior columns were intact (IA indicated mobile disc spaces and IB, ankylosed segments). Type II indicated deficiency of only 1 column (IIA = anterior column and IIB = posterior column). Type III indicated deficiency of both columns (IIIA = kyphosis of ≤60°, IIIB = kyphosis of >60°, and IIIC = buckling collapse). A prospective analysis of 76 patients was performed to determine interobserver variability and the ability of the classification to guide selection of osteotomies of increasing complexity, including the Ponte osteotomy, pedicle subtraction osteotomy, disc bone osteotomy, single vertebrectomy, multiple vertebrectomies, and anterior in situ strut fusion procedure.

RESULTS

The mean age of the 76 patients was 21.2 years, the mean kyphosis was 69.9° (range, 26° to 120°), and the mean follow-up duration was 30 months. Six deformities were classified as IA, 5 as IB, 5 as IIA, 2 as IIB, 13 as IIIA, 35 as IIIB, and 10 as IIIC. Four surgeons classifying the deformities had a high agreement rate (kappa = 0.83), with the highest agreement for Types IA, IB, and IIIB. A correlation between the type of deformity and the osteotomy performed demonstrated that the classification could indicate the type of osteotomy required. All 18 patients with Type-I or II kyphosis were treated with Ponte, pedicle subtraction, or disc bone osteotomy. Forty-three (90%) of the 48 patients with Type IIIA or IIIB underwent vertebrectomy (single in 27 [56%] and multiple in 16 [33%]), and only 5 (10%) underwent disc bone osteotomy. Seven of the 10 patients with Type-IIIC kyphosis were treated with multiple vertebrectomies, with 5 of them needing preoperative halo gravity traction; the other 3 patients underwent an anterior in situ strut fusion procedure.

CONCLUSIONS

The proposed classification based on the morphology of column deficiency, flexibility, and curve magnitude demonstrated a high interobserver agreement and ability to guide selection of the appropriate osteotomy.

CLINICAL RELEVANCE

A novel classification system for kyphosis based on spinal column deficiency, flexibility of disc spaces, and curve magnitude would bring uniformity in management and help guide surgeons in the choice of the appropriate corrective osteotomy.

Comparison of spinal alignment, muscular strength, and quality of life between women with postmenopausal osteoporosis and healthy volunteers

This study compared spinal alignment, muscular strength, and quality of life (QOL) between women with postmenopausal osteoporosis and healthy volunteers. The results indicated that lower QOL in osteoporosis patients may be associated with increased thoracic kyphosis, reduced lean muscle mass, and generalized muscle weakness.

INTRODUCTION

Increased spinal kyphosis is common in patients with osteoporosis and negatively impacts quality of life (QOL). Muscular strength is also important for QOL in patients with osteoporosis. However, spinal kyphosis and muscle weakness also occur in healthy individuals with advancing age. The purposes of this study were thus to compare spinal alignment, muscular strength, and QOL between women with postmenopausal osteoporosis and healthy volunteers.

METHODS

Participants comprised 236 female patients with postmenopausal osteoporosis (mean age, 68.7 years) and 93 healthy volunteer women (mean age, 71.0 years). Body mass index (BMI), angles of spinal kyphosis, back extensor strength, grip strength, and QOL were compared between groups.

RESULTS

BMI, back extensor strength, and grip strength were significantly higher in the volunteer group than in the osteoporosis group (p < 0.01). Both thoracic kyphosis and lumbar lordosis were significantly greater in the osteoporosis group than in the volunteer group (p < 0.01). With regard to QOL, the 36-Item Short-Form Health Survey (SF-36) subscale scores of role physical, bodily pain, general health, and role emotional were all significantly lower in the osteoporosis group than in the volunteer group (p < 0.05 each). SF-36 physical component summary (PCS) score was significantly lower in the osteoporosis group than in the volunteer group (p < 0.001). SF-36 PCS score correlated positively with thoracic kyphosis and negatively with BMI only in the osteoporosis group (p < 0.05 each).

CONCLUSIONS

These results indicated that lower QOL in osteoporosis patients may be associated with increased thoracic kyphosis, reduced lean muscle mass, and generalized muscle weakness.

Targeted spine strengthening exercise and posture training program to reduce hyperkyphosis in older adults: results from the study of hyperkyphosis, exercise, and function (SHEAF) randomized controlled trial

A 6-month randomized controlled trial of spine-strengthening exercise and posture training reduced both radiographic and clinical measures of kyphosis. Participants receiving the intervention improved self-image and satisfaction with their appearance. Results suggest that spine-strengthening exercise and postural training may be an effective treatment option for older adults with hyperkyphosis.

INTRODUCTION

The purpose of the present study is to determine in a randomized controlled trial whether spine-strengthening exercises improve Cobb angle of kyphosis in community-dwelling older adults.

METHODS

We recruited adults ≥60 years with kyphosis ≥40° and enrolled 99 participants (71 women, 28 men), mean age 70.6 ± 0.6 years, range 60-88, with baseline Cobb angle 57.4 ± 12.5°. The intervention included group spine-strengthening exercise and postural training, delivered by a physical therapist, 1-h, three times weekly for 6 months. Controls received four group health education meetings. The primary outcome was change in the gold standard Cobb angle of kyphosis measured from standing lateral spine radiographs. Secondary outcomes included change in kyphometer-measured kyphosis, physical function (modified Physical Performance Test, gait speed, Timed Up and Go, Timed Loaded Standing, 6-Min Walk), and health-related quality of life (HRQoL) (PROMIS global health and physical function indexes, SRS-30 self-image domain). ANCOVA was used to assess treatment effects on change from baseline to 6 months in all outcomes.

RESULTS

There was a -3.0° (95% CI -5.2, -0.8) between-group difference in change in Cobb angle, p = 0.009, favoring the intervention and approximating the magnitude of change from an incident vertebral fracture. Kyphometer-measured kyphosis (p = 0.03) and SRS-30 self-esteem (p < 0.001) showed favorable between-group differences in change, with no group differences in physical function or additional HRQoL outcomes, p > 0.05.

CONCLUSIONS

Spine-strengthening exercise and posture training over 6 months reduced kyphosis compared to control. Our randomized controlled trial results suggest that a targeted kyphosis-specific exercise program may be an effective treatment option for older adults with hyperkyphosis.

TRIAL REGISTRATION NUMBER AND NAME OF TRIAL REGISTER

ClinicalTrials.gov; identifier NCT01751685.

Coronal plane trunk asymmetry is associated with whole-body sagittal alignment in healthy young adolescents before pubertal peak growth

PURPOSE

To investigate coronal plane trunk asymmetry (TA) and its association with sagittal postural alignment in healthy subjects before pubertal peak growth.

METHODS

In this cross-sectional baseline study, 1190 healthy pre-peak growth velocity subjects were included. Coronal plane TA was evaluated using back surface topography. Whole-body sagittal alignment (previously validated and objectively classified as neutral, sway-back or leaning-forward) and sagittal spinopelvic profile (trunk lean, lumbar lordosis, thoracic kyphosis, sacral inclination and length of the posteriorly inclined thoracolumbar segment) were determined, as were height, proportion of trunk to body length, body mass index, generalized joint laxity, and handedness.

RESULTS

Logistic regression analysis yielded overall sagittal posture class to be independently associated with coronal plane TA: having a leaning-forward posture associated with a nearly three times higher odds of coronal TA (p < 0.001) compared to neutrals. A sway-back was 2.2 times more likely to show TA (p = 0.016) than a neutral, yet only in boys. Significant associations with coronal TA were also found for trunk lean, thoracic kyphosis and body mass index. These correlations, however, were gender and posture class specific. The spinal region where asymmetry is seen, varies according to the whole-body sagittal alignment type: primary thoracic curves were the most frequent in leaning-forwards, whereas primary curves in the lumbar or declive thoracolumbar segment were the most common in sway-backs.

CONCLUSIONS

In immature spines without known scoliosis, coronal plane TA is associated with whole-body sagittal alignment. It is more often seen in non-neutral than neutral sagittal posture types. Whether adolescent idiopathic scoliosis is related with postural characteristics before pubertal growth peak, should be addressed in future prospective studies.

Does the position of conus medullaris change with increased thoracolumbar kyphosis in ankylosing spondylitis patients?

To date, only a few reports described the potential factors influencing the position of conus medullaris. One previous study revealed no significant change of conus locations in patients with idiopathic scoliosis; however, the effect of ankylosing spondylitis (AS)-related thoracolumbar kyphosis on conus position remains unexplored. Therefore, we aimed to investigate the variation of conus medullaris terminations in patients with thoracolumbar kyphosis secondary to AS when compared with normal subjects, and evaluated the relationship between conus positions and the magnitude of kyphosis. In this study, MR images of 96 AS patients with thoracolumbar kyphosis, including 86 males and 10 females with an average of 34.6 years (range, 17-65 years), and 100 age-matched normal controls were reviewed to determine the conus terminations in relation to spinal levels. Sagittal parameters of the AS group measured on radiograph included: global kyphosis (GK), thoracic kyphosis (TK), lumbar lordosis (LL), and thoracolumbar junction (TLJ). Finally, conus tips located at the mean level of the lower 3rd of L1 in both groups, there was no significant difference of the conus distributions between AS and control group (P = 0.49). In addition, conus medullaris displayed similar positions in AS patients among various apical region groups (P = 0.88), and no significant difference was found when AS population was stratified into GK ranges of 30° (P = 0.173). Also, no remarkable correlation of the conus positions with GK (r = -0.15, P = 0.15), TK (r = -0.10, P = 0.34), LL (r = -0.10, P = 0.32), and TLJ (r = -0.06, P = 0.54) was identified. This study showed the conus terminations displayed a wide range of distributions in AS patients with thoracolumbar kyphosis, which was similar to normal subjects. Moreover, the conus located at a relatively fixed position and would not be affected by the change of kyphosis magnitude, which is an important knowledge that surgeons should acquire in surgical correction of the deformity in these patients.

Evaluation of thoracic factors after scoliosis surgery in patients with both scoliosis and pectus excavatum

PURPOSE

Pectus excavatum can negatively impact cardiac function during scoliosis surgery. Several authors reported severe hypotension associated with the prone position during scoliosis surgery in children that had both scoliosis and pectus excavatum. However, we could find no studies that evaluated the change in the thoracic factors, such as sternal tilt angle and Haller index after scoliosis surgery in patients with both scoliosis and pectus excavatum. The purpose of this study is to evaluate the change in thoracic factors after surgical treatment for scoliosis associated with pectus excavatum.

METHODS

We performed a retrospective review on 20 patients (10 males and 10 females) who underwent surgical treatment for scoliosis associated with pectus excavatum from August 2004 to April 2014 in our hospital. We investigated the scoliosis diagnosis, preoperative and postoperative Cobb and thoracic kyphosis (TK) angles, the change in TK after surgery and thoracic factors, including the AP and transverse diameters of the chest, the sternal tilt angle, and Haller index.

RESULTS

Patient mean age was 13.2 years old (4-27 years old) at surgery. Types of scoliosis were idiopathic in 8 patients, syndromic in 10, and neuromuscular in 2. The mean Cobb angles were 72.1° preoperatively and 19.0° postoperatively. Curve locations were thoracic in 13 patients, thoracolumbar in 4, and lumbar in 3. Surgical treatment of pectus excavatum was performed in 9 patients (45 %) before scoliosis treatment. Mean sternal tilt angles were 11.5° preoperatively and 11.1° postoperatively. Mean Haller indices were 4.8 preoperatively and 5.3 postoperatively. This was especially true for syndromic or neuromuscular scoliosis and thoracolumbar/lumbar curve type patients in which scoliosis surgery tended to worsen the Haller index.

CONCLUSION

The Haller index increased postoperatively in 11 of 20 patients, which means sternal depression deteriorated after scoliosis surgery in about 50 % of patients. We suggest that surgeons fully assess the thoracic factors in patients with scoliosis and pectus excavatum prior to performing scoliosis surgery and carefully monitor their patient's general condition during surgery.

Vertebral column anomalies in Indo-Pacific and Atlantic humpback dolphins Sousa spp

Conspicuous vertebral column abnormalities in humpback dolphins (genus Sousa) were documented for the first time during 3 photo-identification field studies of small populations in Taiwan, Senegal and Angola. Seven Taiwanese humpback dolphins S. chinensis taiwanensis with vertebral column anomalies (lordosis, kyphosis or scoliosis) were identified, along with 2 possible cases of vertebral osteomyelitis. There was evidence from several individuals photographed over consecutive years that the anomalies became more pronounced with age. Three Atlantic humpback dolphins S. teuszii were observed with axial deviations of the vertebral column (lordosis and kyphosis). Another possible case was identified in a calf, and 2 further animals were photographed with dorsal indents potentially indicative of anomalies. Vertebral column anomalies of humpback dolphins were predominantly evident in the lumbo-caudal region, but one Atlantic humpback dolphin had an anomaly in the cervico-thoracic region. Lordosis and kyphosis occurred simultaneously in several individuals. Apart from the described anomalies, all dolphins appeared in good health and were not obviously underweight or noticeably compromised in swim speed. This study presents the first descriptions of vertebral column anomalies in the genus Sousa. The causative factors for the anomalies were unknown in every case and are potentially diverse. Whether these anomalies result in reduced fitness of individuals or populations merits attention, as both the Taiwanese and Atlantic humpback dolphin are species of high conservation concern.

Cervical sagittal deformity develops after PJK in adult thoracolumbar deformity correction: radiographic analysis utilizing a novel global sagittal angular parameter, the CTPA

PURPOSE

To describe reciprocal changes in cervical alignment after adult spinal deformity (ASD) correction and subsequent development of proximal junctional kyphosis (PJK). This study also investigated these changes using two novel global sagittal angular parameters, cervical-thoracic pelvic angle (CTPA) and the T1 pelvic angle (TPA).

METHODS

Multicenter, retrospective consecutive case series of ASD patients undergoing thoracolumbar three-column osteotomy (3CO) with fusion to the pelvis. Radiographs were analyzed at baseline and 1 year post-operatively. Patients were substratified into upper thoracic (UT; UIV T6 and above) and lower thoracic (LT; UIV below T6). PJK was defined by >10° angle between UIV and UIV + 2 and >10° change in the angle from baseline to post-op.

RESULTS

PJK developed in 29 % (78 of 267) of patients. CTPA was linearly correlated with cervical plumbline (CPL) as a measure of cervical sagittal alignment (R = 0.826, p < 0.001). PJK patients had significantly greater post-operative CTPA and SVA than patients without PJK (NPJK) (p = 0.042; p = 0.021). For UT (n = 141) but not LT (n = 136), PJK patients at 1 year had larger CTPA (4.9° vs. 3.7°, p = 0.015) and CPL (5.1 vs. 3.8 cm, p = 0.022) than NPJK patients, despite similar corrections in PT and PI-LL.

CONCLUSIONS

The prevalence of PJK was 29 % at 1 year follow-up. CTPA, which correlates with CPL as a global analog of cervical sagittal balance, and TPA describe relative proportions of cervical and thoracolumbar deformities. Patients who develop PJK in the upper thoracic spine after thoracolumbar 3CO also develop concomitant cervical sagittal deformity, with increases in CPL and CTPA.

Correlations among four measures of thoracic kyphosis in older adults

SUMMARY

There are many ways to measure thoracic kyphosis ranging from simple clinical to more complex assessments. We evaluated the correlation among four commonly used kyphosis measures: Cobb angle, Debrunner kyphometer, kyphotic index, and the blocks method. Each measure was correlated with the others, confirming high clinical and research applicability.

INTRODUCTION

The purpose of this study was to assess the associations among four commonly used measures of thoracic kyphosis in older adults.

METHODS

Seventy two men and women aged 65-96 were recruited from the San Diego community. Four kyphosis measures were assessed in the same person during a baseline clinic visit. Two measures were done in the lying (L) and two in the standing (ST) position: (1) Cobb angle calculated from dual X-Ray absorptiometry (DXA) images (L), (2) Debrunner kyphometer (DK) angle measured by a protractor (ST), (3) kyphotic index (KI) calculated using an architect's flexicurve ruler (ST), and (4) the blocks method involving counting the number of 1.7 cm-thick blocks required to achieve a neutral head position while lying flat on the DXA table (L). Spearman rank correlation coefficients were used to determine the strength of the association between each kyphosis measure.

RESULTS

Using the Cobb angle as the gold standard, the blocks method demonstrated the lowest correlation (r(s) = 0.63, p < 0.0001), the Debrunner method had a moderate correlation (r(s) = 0.65, p < 0.0001), and the kyphotic index had the highest correlation (r(s) = 0.68, p < 0.0001). The correlation was strongest between the kyphotic index and the Debrunner kyphometer (r(s) = 0.76, p < 0.0001).

CONCLUSION

In older men and women, all four measures of thoracic kyphosis were significantly correlated with each other, whether assessed in the lying or standing position. Thus, any of these measures demonstrate both potential clinical and research utility.

Comparison of the clinical and radiologic outcomes obtained with single- versus two-level anterior cervical decompression and fusion using stand-alone PEEK cages filled with allograft

BACKGROUND

Although anterior cervical decompression and fusion with a stand-alone cage (ACDF-SAC) is accepted as a suitable procedure, the outcomes of the multi-level procedure remain controversial. The aim of this study is to compare the clinical and radiologic outcomes achieved with single versus two-level ACDF-SAC along with identification of the factors that contribute to loss in mean disc height (MDH) and change in cervical lordotic angle (CLA).

METHODS

A total of 109 consecutive patients who underwent ACDF-SAC for degenerative spondylosis were reviewed. Patients were divided into two groups according to surgical level (group A, single; group B, two) and were followed for at least 1 year. Clinical outcomes were evaluated using the visual analog scale (VAS) and Robinson's criteria. The fusion and subsidence rates, MDH, CLA, anterior, and posterior vertebral body height of the fused segments (AVBH, PVBH) were measured retrospectively from plain radiographs.

RESULTS

Clinical outcomes were similar in both groups, in terms of decreasing VAS score and a grade higher than "good" by Robinson's criteria. The fusion and subsidence rates for each group were found to be 92.2, 91.1, 14.1, and 20.0 %, respectively. The MDH (mm) increased by 1.44 ± 0.96 in group A, 1.57 ± 0.79 and 1.66 ± 0.69 for each surgical level in group B over the 12 postoperative months. The CLA (°) decreased by 1.70 ± 4.04 and 0.75 ± 6.12 over the 12 postoperative months from its presurgery value, the rate of kyphosis >5° was 26.6 and 22.2 % for each group. All compared values were not significantly different between the two groups. Correlation analysis revealed that the AVBH/PVBH ratio exhibited a positive correlation with CLA change in both groups (r = 0.368, 0.397; p = 0.018, 0.040).

CONCLUSIONS

The overall outcomes achieved with two-level ACDF-SAC were similar to those achieved with single-level ones. In addition, the AVBH/PVBH ratio might be a predictable marker for a postoperative kyphosis.

Thoracic kyphosis and rate of incident vertebral fractures: the Fracture Intervention Trial

SUMMARY

Biomechanical analyses support the theory that thoracic spine hyperkyphosis may increase risk of new vertebral fractures. While greater kyphosis was associated with an increased rate of incident vertebral fractures, our analysis does not show an independent association of kyphosis on incident fracture, after adjustment for prevalent vertebral fracture. Excessive kyphosis may still be a clinical marker for prevalent vertebral fracture.

INTRODUCTION

Biomechanical analyses suggest hyperkyphosis may increase risk of incident vertebral fracture by increasing the load on vertebral bodies during daily activities. We propose to assess the association of kyphosis with incident radiographic vertebral fracture.

METHODS

We used data from the Fracture Intervention Trial among 3038 women 55-81 years of age with low bone mineral density (BMD). Baseline kyphosis angle was measured using a Debrunner kyphometer. Vertebral fractures were assessed at baseline and follow-up from lateral radiographs of the thoracic and lumbar spine. We used Poisson models to estimate the independent association of kyphosis with incident fracture, controlling for age and femoral neck BMD.

RESULTS

Mean baseline kyphosis was 48° (SD = 12) (range 7-83). At baseline, 962 (32%) participants had a prevalent fracture. There were 221 incident fractures over a median of 4 years. At baseline, prevalent fracture was associated with 3.7° greater average kyphosis (95% CI 2.8-4.6, p < 0.0005), adjusting for age and femoral neck BMD. Before adjusting for prevalent fracture, each 10° greater kyphosis was associated with 22% increase (95% CI 8-38%, p = 0.001) in annualized rate of new radiographic vertebral fracture, adjusting for age and femoral neck BMD. After additional adjustment for prevalent fracture, estimated increased annualized rate was attenuated and no longer significant, 8% per 10° kyphosis (95% CI -4 to 22%, p = 0.18).

CONCLUSIONS

While greater kyphosis increased the rate of incident vertebral fractures, our analysis does not show an independent association of kyphosis on incident fracture, after adjustment for prevalent vertebral fracture. Excessive kyphosis may still be a clinical marker for prevalent vertebral fracture.

[RESEARCH PROGRESS OF ROLE OF ESTROGEN AND ESTROGEN RECEPTOR ON ONSET AND PROGRESSION OF ADOLESCENT IDIOPATHIC SCOLIOSIS]

OBJECTIVE

To review the recent progress in research on the role of estrogen and estrogen receptor on the onset and progression of adolescent idiopathic scoliosis (AIS).

METHODS

The recently published clinical and experimental literature at home and abroad on abnormality of estrogen and its receptor in AIS was reviewed and summarized.

RESULTS

There are many abnormal changes of estrogen and estrogen receptor in most AIS patients, including higher serum estrogen concentration, unusual cellular response to estrogen, late age at menarche, and gene polymorphisms of estrogen receptor, which are closely associated with AIS predisposition, curve severity, and scoliosis progression.

CONCLUSION

Estrogen and its receptor participate in the onset and progression of AIS by certain mechanisms, but exact mechanism remains indefinite, which needs further research to better define the role of estrogen and its receptor in AIS.

Vertebral column deformities in white-beaked dolphins from the eastern North Atlantic

Five white-beaked dolphins Lagenorhynchus albirostris with outwardly vertebral kyphosis, kyphoscoliosis or lordosis were identified during a photo-identification survey of over 400 individuals (2002-2013) in Faxaflói and Skjálfandi Bays, Iceland. In addition, 3 stranding reports from Denmark, The Netherlands and the UK were analysed, providing both external observation and post mortem details of axial deviations of the vertebral column in this species. Two of the free-ranging cases and 2 of the stranded specimens appeared to have an acquired disease, either as a direct result of trauma, or indirectly from trauma/wound and subsequent infection and bony proliferation, although we were unable to specifically identify the causes. Our data represent a starting point to understand vertebral column deformations and their implications in white-beaked dolphins from the eastern North Atlantic. We recommend for future necropsy cases to conduct macro- and microscopic evaluation of muscle from both sides of the deformed region, in order to assess chronic or acute conditions related to the vertebral deformations and cause of death.

Comparison of modic changes in the lumbar and cervical spine, in 3167 patients with and without spinal pain

BACKGROUND CONTEXT

There are few comparisons of Modic changes (MCs) in the lumbar and cervical spine.

PURPOSE

Compare the prevalence of MCs in the lumbar and cervical spine, and determine how MC prevalence depends on spinal pain, age, disc degeneration, spinal level, and the presence or absence of kyphosis.

STUDY DESIGN

Retrospective clinical survey.

MATERIALS AND METHODS

Magnetic resonance images (MRIs) were compared from five patient groups: 1. 1223 patients with low-back pain/radiculopathy only; 2. 1023 patients with neck pain/radiculopathy only; 3. 497 patients with concurrent low-back and neck symptoms; 4. 304 asymptomatic subjects with lumbar MRIs; and 5. 120 asymptomatic subjects with cervical MRIs.

RESULTS

The prevalence of MCs was higher in those with spinal pain than in those without, both in the lumbar spine (21.0% vs 10.5%) and cervical spine (8.8% vs 3.3%). Type II MCs were most common and Type III were least common in all groups. The prevalence of lumbar MCs in people with back pain was little affected by the presence of concurrent neck pain, and the same was true for the prevalence of cervical MCs in people with neck pain with or without concurrent back pain. When symptomatic patients were reclassified into two groups (back pain, neck pain), the prevalence of lumbar MCs in people with back pain was greater than that of cervical MCs in people with neck pain. The prevalence of lumbar and cervical MCs increased with age, disc degeneration, (descending) spinal level, and increased kyphosis.

CONCLUSIONS

There is a significantly higher prevalence of MCs in patients with back and neck pain. The reported association with increased kyphosis (flat back) is novel.

Deletion of Mecom in mouse results in early-onset spinal deformity and osteopenia

Recent studies have indicated a role for a MECOM allele in susceptibility to osteoporotic fractures in humans. We have generated a mutation in Mecom in mouse (termed ME(m1)) via lacZ knock-in into the upstream transcription start site for the gene, resulting in disruption of Mds1 and Mds1-Evi1 transcripts, but not of Evi1 transcripts. We demonstrate that ME(m1/m1) mice have severe kyphoscoliosis that is reminiscent of human congenital or primary kyphoscoliosis. ME(m1/m1) mice appear normal at birth, but by 2weeks, they exhibit a slight lumbar lordosis and narrowed intervertebral space. This progresses to severe lordosis with disc collapse and synostosis, together with kyphoscoliosis. Bone formation and strength testing show that ME(m1/m1) mice have normal bone formation and composition but are osteopenic. While endochondral bone development is normal, it is markedly dysplastic in its organization. Electron micrographs of the 1week postnatal intervertebral discs reveals marked disarray of collagen fibers, consistent with an inherent weakness in the non-osseous connective tissue associated with the spine. These findings indicate that lack of ME leads to a complex defect in both osseous and non-osseous musculoskeletal tissues, including a marked vertebral osteopenia, degeneration of the IVD, and disarray of connective tissues, which is likely due to an inherent inability to establish and/or maintain components of these tissues.

Preventive effects of conservative treatment with short-term teriparatide on the progression of vertebral body collapse after osteoporotic vertebral compression fracture

The progression of fractured vertebral collapse is not rare after a conservative treatment of vertebral compression fracture (VCF). Teriparatide has been shown to directly stimulate bone formation and improve bone density, but there is a lack of evidence regarding its use in fracture management. Conservative treatment with short-term teriparatide is effective for decreasing the progression of fractured vertebral body collapse.

INTRODUCTION

Few studies have reported on the prevention of collapsed vertebral body progression after osteoporotic VCF. Teriparatide rapidly enhances bone formation and increases bone strength. This study evaluated preventive effects of short-term teriparatide on the progression of vertebral body collapse after osteoporotic VCF.

METHODS

Radiographs of 68 women with single-level osteoporotic VCF at thoracolumbar junction (T11-L2) were reviewed. Among them, 32 patients were treated conservatively with teriparatide (minimum 3 months) (group I), and 36 were treated with antiresorptive (group II). We measured kyphosis and wedge angle of the fractured vertebral body, and ratios of anterior, middle, and posterior heights of the collapsed body to posterior height of a normal upper vertebra were determined. The degree of collapse progression was compared between two groups.

RESULTS

The progression of fractured vertebral body collapse was shown in both groups, but the degree of progression was significantly lower in group I than in group II. At the last follow-up, mean increments of kyphosis and wedge angle were significantly lower in group I (4.0° ± 4.2° and 3.6° ± 3.6°) than in group II (6.8° ± 4.1° and 5.8° ± 3.5°) (p = 0.032 and p = 0.037). Decrement percentages of anterior and middle border height were significantly lower in group I (9.6 ± 10.3 and 7.4 ± 7.5 %) than in group II (18.1 ± 9.7 and 13.8 ± 12.2 %) (p = 0.001 and p = 0.025), but not in posterior height (p = 0.086).

CONCLUSIONS

In female patients with single-level osteoporotic VCF at the thoracolumbar junction, short-term teriparatide treatment did not prevent but did decrease the progression of fractured vertebral body collapse.

Inclinometer-based measures of standing posture in older adults with low bone mass are reliable and associated with self-reported, but not performance-based, physical function

The association between posture and physical function during daily activities in people at risk for osteoporotic fracture is not clear. We report the reliability of measuring posture using the digital inclinometer and how these measures relate to performance-based and self-reported physical function.

INTRODUCTION

This study aims to determine the reliability of a simple clinical method for assessing spine curvatures in people with low bone mass and the association between spine curvature measures and pain, physical function (mobility/activities of daily living (ADL)) and quality of life.

METHODS

One rater assessed 36 high-functioning adults, aged 52-82 years, attending an outpatient osteoporosis clinic. A digital inclinometer was used to measure lumbosacral angle (S), lumbar standing posture (L), and thoracic standing posture (T) and ADL performance was assessed using the short form of the Safe Functional Motion test (SFM-6), on two occasions approximately 8.7 days apart. Participants reported average pain intensity over the past week and completed the Timed Up and Go test (TUGT) and the mini-Osteoporosis Quality of Life questionnaire (mini-OQLQ). Acceptable reliability was determined using the intraclass correlation coefficient (ICC). Associations were determined using Pearson's correlation coefficients (r) (and Spearman's rho (r s), for non-normal data).

RESULTS

ICC (95 % CI) for S, L, and T = 0.91 (0.82, 0.95), 0.90 (0.82, 0.95), and 0.91 (0.84, 0.95), respectively, for test-retest reliability. Thoracic standing posture was associated with the ADL domain of the mini-OQLQ (r s = -0.39) and the TUGT (r = 0.42). Standing posture was not related to pain or total SFM-6 score.

CONCLUSIONS

Digital inclinometer measures provide a quick highly reliable, valid, direct assessment of kyphosis. Use of these measures in the clinical setting is expected to facilitate identification and effective management of postural impairments (e.g., trunk extensor muscle weakness, vertebral fracture) associated with osteoporosis.

Vertebral column resection for complex congenital kyphoscoliosis and type I split spinal cord malformation

INTRODUCTION

Congenital progressive kyphoscoliosis associated with split spinal cord malformation (SSCM) is a very rare disease.

METHODS AND RESULTS

Here, we present the case of a 23-year-old woman who was found kyphoscoliosis when she was 10 years old and developed rapidly. Thereafter, no management was proposed before her consultation at our center. On examination, numbness was found in the right low limbs, kyphoscoliosis was detected in thoracolumbar, the trunk deviated to the right on standing view and curvature of the thoracolumbar spine was left-sided, the left rib hump was severe and there was little muscle tissue felt under the right side paravertebral area, the pelvis was oblique with the right side higher than the left side, the right arcus costarum was 5 cm below the right iliac crest. One-stage corrective surgery was determined, at first, halo-wheelchair traction gradually with increased traction weights out of hospital for a month; then, after a reasonable correction achieved without any neurological deficits. The one-stage operation was taken through single posterior segmental pedicle screw instrumented fusion with VCR between T12 and L1. Post-operative recovery was uneventful and there were no complications, she was discharged 10 days post operation. At 2 years follow-up, the patient's outcome is excellent with balance and correction of the deformity.

CONCLUSION

Based on the Grand Round case and relevant literature, we discuss the different options for the treatment of congenital kyphoscoliosis associated with type I SSCM. In the patient whose kyphoscoliosis is severe and rigid, we recommend an initial release followed by halo-wheelchair traction gradually to correct the deformity, once optimal correction acquires during the traction, the posterior instrumented fusion with VCR upper the bony spur could be done safely without the resection of bony spur.

The characteristics of spinopelvic sagittal alignment in patients with lumbar disc degenerative diseases

PURPOSE

A comparative study of the spinopelvic sagittal alignment in patients with lumbar disc degeneration or herniation (LDD/LDH) in normal population was designed to analyse the role of sagittal anatomical parameter (pelvic incidence, PI) and positional parameters in the pathogenesis and development of the disease. Several comparative studies of these patients with asymptomatic controls have been done. However, in previous studies without lumbar MRI, a certain number of asymptomatic LDD patients should have been included in the control group and then impacted on the results.

METHODS

Based on MRI findings, we divided 60 LDD or LDH patients and 110 asymptomatic volunteers into the normal group (NG) and the degeneration group (DG), which was further subdivided into the symptomatic (SDG) and asymptomatic (ADG) subgroups according to patients' symptoms. Standing full spine radiographs were used to measure sagittal parameters, including PI, sacral slope (SS), pelvic tilt (PT), lumbar lordosis (LL), thoracic kyphosis (TK), sagittal vertical axis (SVA), and sacrum-bicoxofemoral distance (SFD).

RESULTS

The PI, SS and LL in DG were significantly lower than NG, while the SVA and SFD were significantly greater (P < 0.05). PI correlated well with the SS and LL in all subjects. However, the trend lines of SS or LL over PI were downward in DG. PI was similar in SDG and ADG (P = 0.716) but SS and LL were significantly lower and SVA was significantly greater (P < 0.05).

CONCLUSIONS

PI may play a predisposing role in the pathogenesis of lumbar disc degenerative diseases. The secondary structural and compensatory factors would lead to a straighter spine after disc degenerative change.

The Universal Clamp hybrid system: a safe technique to correct deformity and restore kyphosis in adolescent idiopathic scoliosis

PURPOSE

Adolescent idiopathic scoliosis (AIS) is a tridimensional deformity characterized by coronal and sagittal profiles changes. We present a series of 62 patients affected by AIS and treated by thoracic Universal Clamps and transpedicular lumbar screws hybrid system.

METHODS

Mean age was 13 years. Average pre-operative Cobb angle was 63° ± 12°. Patients were divided into two groups depending on the kyphosis angle: lower than 45° (51 patients, 82.3 %, mean 21° ± 3°) and higher than 45° (11 patients, 17.7 %, mean 62° ± 6°).

RESULTS

The average percentage of coronal correction was 70 ± 3 % (mean post-operative Cobb angle 19° ± 4°, P < 0.001). In patients with pre-operative physiological thoracic kyphosis-hypokyphosis, we observed an increase in the average value (32° ± 4°, P < 0.001), while in patients with pre-operative hyperkyphosis, mean decrease of thoracic kyphosis was 19° ± 3° (43° ± 4°, P < 0.001).

CONCLUSIONS

This case-series study showed the efficacy and safety of Universal Clamp hybrid system in correcting coronal deformity and restoring physiological thoracic kyphosis in patients affected by AIS.

Relationship of thoracic kyphosis and lumbar lordosis to bone mineral density in women

The relationship between spinal curvature and bone mineral density (BMD) in women was examined. Significant relationships were observed between spinal curvature and BMD in both pre- and postmenopausal women. Excessive spinal curvature may be associated with low bone mass in premenopausal women.

INTRODUCTION

The purpose of this study was to examine the associations between spinal measurements of thoracic and lumbar curvatures and bone mineral density in pre- and postmenopausal women.

METHODS

The data for this study were obtained from the Texas Woman's University Pioneer Project. Female participants (n = 242; premenopausal n = 104, postmenopausal n = 138) between the ages of 18 and 60 years were evaluated on multiple health measures. Thoracic and lumbar curvatures were measured with a 24-in. (60 cm) flexicurve. Bone mineral density was assessed via dual-energy X-ray absorptiometry (Lunar DPX IQ, version 4.6e). Pearson correlations and logistic regression analysis were used to examine the associations between the obtained spinal curvature measurements and bone mineral density. Significance was set at p < .05.

RESULTS

Significant correlations were observed for the femoral neck and lumbar spine bone mineral density with thoracic and lumbar curve in premenopausal women (r = -.344 to - .525; p < .001). Slightly weaker, but significant, correlations were observed for femoral neck and lumbar spine in relation to thoracic and lumbar curve in postmenopausal women (r = -.288 to -.397; p < .01). Premenopausal women with thoracic curvature greater than 4 cm had a greater risk of having low bone mass compared to premenopausal women with less than 4 cm of curvature (odds ratio = 3.982, 95 % CI = 1.206, 13.144).

CONCLUSIONS

The observed negative relationship suggests that as either thoracic or lumbar curvature increases, the regional bone mineral density decreases in both pre- and postmenopausal women.

[Analysis of ribs and intraspinal anomalies in congenital scoliosis]

OBJECTIVE

To investigate the incidences and characteristics of the ribs and intraspinal abnormalities in surgical patients with congenital scoliosis.

METHODS

We conducted a retrospective study of the medical records and spine radiographs of 118 patients underwent surgical treatment between January 2010 and March 2011 with congenital scoliosis. The average age was 14 years (3-50 years).Fifty-two were male and 66 were female patients. The rib and intraspinal abnormalities were compared in different vertebral anomalies. Pearson's χ(2) test were used to analyze the incidence of anomalies of the ribs and vertebrae, as well as intraspinal anomalies.

RESULTS

A total of 57 (48.3%) patients were found to have intraspinal abnormalities.Split cord deformities were identified to be the most common intraspinal anomaly (32.2%), followed by syringomyelia (21.2%).Sixty-nine patients (58.5%) had rib anomalies, which occurring on the concavity of the scoliosis was most frequent. The patients with mixed deformity and failure of segment were found to have a higher incidence of rib anomaly than those with failure formation (χ(2) = 14.05, P < 0.01). The patients with multiple level malformations were found to have significantly higher incidence of rib anomaly than those with single level malformation (χ(2) = 27.50, P < 0.01).Intraspinal anomalies occurred in 42 of 69 patients (60.9%) with rib anomalies and 15 of 49 patients (30.6%) without rib anomalies in congenital scoliosis. The occurrence of intraspinal malformation has significant difference with or without rib anomalies in congenital scoliosis (χ(2) = 10.5, P < 0.01).

CONCLUSIONS

The intraspinal malformation is common in patients with mixed defects and failures of segmentation. The rib anomalies occurring on the concavity of the scoliosis is most frequent. The incidence of intraspinal anomaly is significant higher in the patients with rib anomalies than those without rib anomalies. Both the occurrence and type of rib anomaly, combined with vertebral deformity are helpful in forecasting the occurrence of intraspinal abnormalis.

Influence of non-traumatic thoracic and lumbar vertebral fractures on sagittal spine alignment assessed by radiation-free spinometry

Due to missing indications for specific diagnostics, the majority of non-symptomatic vertebral fractures are not diagnosed. This study shows the ability of radiation-free spinometry to assess sagittal spine parameters to raise suspicion for new non-traumatic thoracic and lumbar vertebral fractures and indicate specific diagnostics.

INTRODUCTION

The primary aim of this study was to investigate the accuracy of radiation-free spinometry to predict new non-traumatic vertebral fractures (VF) by the assessment of thoracic kyphosis (TK), lumbar lordosis (LL), and trunk inclination.

METHODS

Three hundred sixty-one patients (278 females and 83 males; age, 67.0 ± 8.6 years) were enrolled. In 86 women and 24 men, at least one non-traumatic VF was confirmed by radiography, MRI, and/or CT. Spinometry (video rasterstereography) was used to assess TK, LL, and trunk inclination. Receiver operating characteristic (ROC) and multivariate logistic regression analyses were performed to test the influence of age, sex, number, location, and grade of fractures on sagittal spine alignment.

RESULTS

TK, LL, and trunk inclination were associated with advancing age (p < 0.05). Patients with prevalent thoracic and lumbar VFs showed increased TK (p < 0.001), decreased LL (p < 0.001), and increased trunk inclination (p < 0.001) in comparison to patients without VFs. ROC analysis revealed that the combination of TK and LL presented with the best predictive accuracy to raise suspicion for new grade 2 or grade 3 VFs in the thoracic and the lumbar spine (AUC, 0.752-0.771). Odds ratio (OR) showed an increased risk for VFs with increased TK (OR, 1.05-1.11; p < 0.001) and LL (1.05-1.07; p < 0.001) in specified regions of interest. A TK <50° (sensitivity, 88-100 %; specificity, 23-25 %) and LL (78-92 %; 24-27 %) were considered as appropriate cutoffs for future screening.

CONCLUSION

Spinometry showed better predictive accuracy than historical height loss. Severe changes of TK and LL may help to raise suspicion of new VFs radiation-free and indicate proper diagnostics, such as radiographs, MRI, or CT.

Apoptosis of endplate chondrocytes in post-laminectomy cervical kyphotic deformity. An in vivo animal model in sheep

PURPOSE

The present study was performed to establish an animal model of cervical kyphosis after laminectomy (C2-C5), and to determine the role of endplate chondrocytes apoptosis in cervical kyphosis after laminectomy.

METHODS

Twenty-four 3-month-old sheep were randomly divided into two groups: the laminectomy group (n = 12), and the control group (n = 12). The cervical spine alignment was evaluated on a lateral cervical spine X-ray using Harrison's posterior tangent method before surgery and at follow-up. Cartilaginous endplate chondrocyte apoptosis was confirmed using transmission electron microscopy and terminal deoxyribonucleotidyl transferase (TdT)-mediated dUTP nick-end labelling.

RESULTS

The mean preoperative cervical curvature (C2-5) in the surgery group was -15.8°. The cervical curvature was 19.1° at 3 months post-operation and decreased to 20.2° at the final follow-up postoperatively. The cervical curvature was significantly decreased in the laminectomy group compared with the control group at the last follow-up (P < 0.001), which was a direct indication of kyphotic change. The incidence of apoptotic cells in the surgery group was significantly higher at the 3- and 6-month follow-up than the incidence in the control group.

CONCLUSIONS

The frequency of endplate chondrocyte apoptosis in the laminectomy group was significantly higher than in the control group, indicating that chondrocyte apoptosis may play a pivotal role in the progress of post-laminectomy cervical kyphosis.

Risk factors affecting progressive collapse of acute osteoporotic spinal fractures

We prospectively investigated related clinical and radiological risk factors for progression following acute osteoporotic spinal fractures. Fracture location, morphological feature (mid-portion), and involvement of vertebral posterior wall were statistical significant risk factors considering increase of height loss and kyphotic angle, and occurrence of intravertebral cleft sign as a progressive collapse.

INTRODUCTION

This study was designed to investigate the clinical and radiological risk factors related to progressive collapse of acute osteoporotic spinal fractures (OSF).

METHODS

In total, 100 patients with acute OSF were prospectively enrolled at a single institute. Five pathological fractures were excluded. Twelve patients dropped out of the study because of conversion to surgical treatment during follow-up. Eight patients were excluded as follow-up losses. Thus, 75 patients were analyzed. Clinical data and radiological data were recorded and analyzed. As a definition of progressive OSF, height loss≥15%, kyphotic angle≥10°, and the occurrence of an intravertebral cleft sign at the 6-month follow-up compared to the initial values were adopted. Correlation analysis and multiple logistic regression analyses were performed to elucidate the related clinical or radiological factors for progressive OSF.

RESULTS

The occurrence of intravertebral cleft was not related to any significant differences in the clinical results and was only related to the fracture level in the regression analysis. A ≥15% increase in height loss and a ≥10° increase in kyphotic angle were related to worse clinical results. Mid-portion type fractures and involvement of the posterior wall were significant risk factors with relatively high odds ratios for progressive OSF under these criteria.

CONCLUSION

A thoracolumbar fracture, a mid-portion type fracture, and involvement of the vertebral posterior wall are relative risk factors for progressive collapse following acute OSF. More attention should be paid to patients with OSF and these risk factors during conservative management.

Proximal junctional kyphosis as a distinct form of adjacent segment pathology after spinal deformity surgery: a systematic review

STUDY DESIGN

Systematic review.

OBJECTIVE

To review the literature on proximal junctional kyphosis (PJK) as a specific form for proximal adjacent segment pathology and report on the incidence, timing, risk factors, and effect on health-related quality of life (HRQOL) outcomes reported for PJK.

SUMMARY OF BACKGROUND DATA

PJK is a complication of spinal deformity surgery that can compromise outcomes and necessitate revision surgery. Multiple risk factors have been associated with PJK, making the etiology multifactorial. Knowledge of the risk factors is important for minimizing the occurrence of PJK and to allow surgeons to take measures for its prevention when possible.

METHODS

A systematic search of PubMed, CINAHL, EMBASE, the Cochrane Library, and Google Scholar through February 15, 2012, was performed. The focus was on studies designed to evaluate PJK in patients who had surgery for scoliosis and/or kyphosis. Adjusted effect sizes and significance based on adjusting for confounders were reported if available, otherwise, crude risk ratios and 95% confidence intervals were calculated.

RESULTS

The search yielded 85 citations and 8 met the criteria for inclusion. The incidence of PJK ranged from 17% to 39% and the majority seemed to occur within 2 years of surgery. The most common patient demographic associated with a higher PJK risk was increased age. Surgery-related risk factors were fusions to the sacrum, combined anterior/posterior surgery, thoracoplasty, and upper instrumented vertebra at T1-T3. Postoperative hypokyphosis or hyperkyphosis was associated with an increased risk of PJK. Despite the presence of PJK, health-related quality of life outcomes were not affected.

CONCLUSION

Patients at higher risk for PJK are those who are of older age, who had fusions to the sacrum, combined anterior/posterior surgery, thoracoplasty, and an upper instrumented vertebra at T1-T3. Despite the presence of PJK, no differences were noted in health-related quality of life outcomes.

CONSENSUS STATEMENT

1. The risk of developing PJK above a spinal deformity fusion is 17% to 39%, with most noted by 2 years postoperative.

LEVEL OF EVIDENCE

Moderate. Strength of Statement: Strong. 2. The risk factors of PJK development include increased age, fusion to sacrum, combined ASF/PSF, thoracoplasty, UIV at T1–T3, and nonanatomic restoration of thoracic kyphosis.

LEVEL OF EVIDENCE

Low. Strength of Statement: Weak. 3. The development of PJK does not seem to have a detrimental effect on HRQOL outcomes, at least in milder/nonrevision forms.

LEVEL OF EVIDENCE

Moderate. Strength of Statement: Weak.

Does postsurgical cervical deformity affect the risk of cervical adjacent segment pathology? A systematic review

STUDY DESIGN

Systematic review.

OBJECTIVE

To assess whether the presence or magnitude of postsurgical malalignment in the coronal (scoliosis) or sagittal plane (kyphosis/spondylolisthesis) affects the risk of cervical adjacent segment pathology (ASP).

SUMMARY OF BACKGROUND DATA

ASP occurs in selected patients who have undergone surgical treatment for cervical spondylosis. The reasons are multifactorial; however, postsurgical alignment may play a key role. To elucidate this issue, a systematic review of the literature was undertaken.

METHODS

A systematic search in PubMed was conducted for literature published in English language through February 15, 2012. Studies in adults, designed to evaluate postsurgical sagittal or coronal malalignment as risk factors for radiographical or clinical ASP, were sought. Studies of pediatric or oncological patients were excluded. Case reports, case series, and patient populations of less than 10 patients were also excluded. Unadjusted risk ratios (RRs) and 95% confidence intervals were calculated to evaluate the association between alignment and the risk for developing ASP.

RESULTS

The search yielded 338 citations. Of that, 311 were excluded at the title and abstract level. Of the 27 selected for full-text review, 5 poor-quality retrospective studies met the inclusion criteria and described sagittal imbalance measures as risk factors for radiological ASP after anterior surgery. No studies examined ASP after posterior cervical surgery. Three studies provided data from which unadjusted RRs and 95% confidence intervals could be calculated. These studies showed an increased risk of ASP associated with malalignment (RR, 2.24 [95% confidence interval, 1.40-3.56]; RR, 2.40 [1.33, 4.33]; RR, 1.32 [0.96, 1.81]). No study evaluating coronal imbalance as a risk factor for cervical ASP was found and none reported on clinical ASP.

CONCLUSION

There is low-grade evidence from 3 published studies that postsurgical sagittal imbalance may increase the risk for cervical radiological ASP.

CONSENSUS STATEMENT

An attempt should be made to maintain or restore cervical lordosis in surgical intervention for cervical disorders. Strength of Statement: Weak.

Strain-specific hyperkyphosis and megaesophagus in Add1 null mice

The three adducin proteins (α, β, and γ) share extensive sequence, structural, and functional homology. Heterodimers of α- and β-adducin are vital components of the red cell membrane skeleton, which is required to maintain red cell elasticity and structural integrity. In addition to anemia, targeted deletion of the α-adducin gene (Add1) reveals unexpected, strain-dependent non-erythroid phenotypes. On an inbred 129 genetic background, Add1 null mice show abnormal inward curvature of the cervicothoracic spine with complete penetrance. More surprisingly, a subset of 129-Add1 null mice develop severe megaesophagus, while examination of peripheral nerves reveals a reduced number of axons in 129-Add1 null mice at four months of age. These unforeseen phenotypes, described here, reveal new functions for adducin and provide new models of mammalian disease.

Role of lumbar interspinous distraction on the neural elements

The interspinous distraction devices are used to treat variable pathologies ranging from facet syndrome, diskogenic low back pain, degenerative spinal stenosis, diskopathy, spondylolisthesis, and instability. The insertion of a posterior element with an interspinous device (ISD) is commonly judged responsive to a relative kyphosis of a lumbar segment with a moderate but persistent increase of the spinal canal and of the foraminal width and area, and without influence on low-grade spondylolisthesis. The consequence is the need of shared specific biomechanical concepts to give for each degenerative problem the right indication through a critical analysis of all available experimental and clinical biomechanical data. We reviewed systematically the available clinical and experimental data about kyphosis, enlargement of the spinal canal, distraction of the interspinous distance, increase of the neural foramina, ligamentous structures, load of the posterior annulus, intradiskal pressure, strength of the spinous processes, degeneration of the adjacent segment, complications, and cost-effectiveness of the ISD. The existing literature does not provide actual scientific evidence over the superiority of the ISD strategy, but most of the experimental and clinical data show a challenging potential. These considerations are applicable with different types of ISD with only few differences between the different categories. Despite--or because of--the low invasiveness of the surgical implantation of the ISD, this technique promises to play a major role in the future degenerative lumbar microsurgery. The main indications for ISD remain lumbar spinal stenoses and painful facet arthroses. A clear documented contraindication is the presence of an anterolisthesis. Nevertheless, the existing literature does not provide evidence of superiority of outcome and cost-effectiveness of the ISD strategy over laminectomy or other surgical procedures. At this time, the devices should be used in clinical randomized independent trials in order to obtain more information concerning the most advantageous optimal indication or, in selected cases, to treat tailored indications.

[Effectiveness comparison between pedicle subtraction osteotomy and non-osteotomy techniques in treatment of medium-to-severe kyphoscoliosis]

OBJECTIVE

To evaluate the effectiveness of pedicle subtraction osteotomy (PSO) and non-osteotomy techniques in treatment of medium-to-severe kyphoscoliosis by retrospective studies.

METHODS

Between January 2005 and January 2009, 99 patients with medium-to-severe kyphoscoliosis were treated by PSO (PSO group, n = 46) and non-osteotomy technique (non-osteotomy group, n = 53) separately. There was no significant difference in sex, age, Cobb angle of scoliosis on coronal plane, and Cobb angle of kyphosis on saggital plane between 2 groups (P > 0.05). The operation time and blood loss were recorded; the Cobb angle of scoliosis on coronal plane and kyphosis on sagittal plane were measured at pre- and postoperation to caculate the rates of correction on both planes.

RESULTS

The operation was successfully completed in all the patients. The operation time and blood loss of the patients in PSO group were significantly greater than those of the patients in non-osteotomy group (P < 0.05). All patients were followed up 12-56 months (mean, 22.4 months); no spinal cord injury occurred, and bone fusion was achieved at last follow-up. The Cobb angles of scoliosis and kyphosis at 2 weeks and last follow-up were significantly improved when compared with the preoperative angles in the patients of 2 groups (P < 0.05). There was no significant difference in Cobb angle of scoliosis and the rate of correction between 2 groups (P > 0.05), but the correction loss of PSO group was significantly smaller than that of non-osteotomy group (P < 0.05) at last follow-up. At 2 weeks and last follow-up, the Cobb angle of kyphosis, the rate of correction, and correction loss were significantly better in PSO group than in non-osteotomy group (P < 0.05).

CONCLUSION

There is no signifcant difference in scoliosis correction between PSO and non-osteotomy techniques. PSO can get better corrective effect in kyphosis correction than non-osteotomy technique, but the operation time and blood loss would increase greatly.

Measurement of spinal sagittal curvatures using the laser triangulation method

The purpose of the first part of the study was to establish the variability of repeated measurements in different measuring conditions. In the second part, we performed in a large number of patients, a measurement of thoracic kyphosis and lumbar lordosis and compared them to age, gender, and level of nourishment. In the first part, measurements were performed on a plastic model of the back of a patient with a rigid and a normal spine. In the second part, 250 patients participated in the study (126 men and 124 women). For measuring spinal curvatures we used an apparatus for laser triangulation constructed at the Faculty of Mechanical Engineering, University of Ljubljana. A comparison of 30 repeated measurements was shown as the average value +/- 2 SD which included 95% of the results. Thirty repeated readings of one 3D measurement: thoracic kyphosis 41.2 degrees +/- 0.6 degrees, lumbar lordosis 4.4 degrees +/- 1.2 degrees; 30 measurements on a plastic model: thoracic kyphosis 36.8 degrees +/- 1.2 degrees, lumbar lordosis 30.9 degrees +/- 2.0 degrees; 30 measurements on a patient with a rigid spine: thoracic kyphosis 41.5 degrees +/- 2.4 degrees, lumbar lordosis 4.0 degrees +/- 1.8 degrees; 30 measurements on a patient with a normal spine: thoracic kyphosis 48.8 degrees +/- 7.4 degrees, lumbar lordosis 21.1 degrees +/- 4.4 degrees. The average size of thoracic kyphosis in 250 patients was 46.8 degrees (SD 10.1 degrees) and lumbar lordosis 31.7 degrees (SD 12.5 degrees). The angle size was statistically significantly correlated to gender (increased thoracic kyphosis and lumbar lordosis in women) and body mass index (increased thoracic kyphosis and lumbar lordosis in more nourished patients). Age was not significantly correlated to the observed angles. During measurements of the spinal angles it was important to pay attention to relaxation and the patient's position as well as to perform more measurements providing the average value. The age and the level of nourishment influence the size of the sagittal spinal angles. In the observed sample the effect of age was not confirmed.

Intra- and interobserver repeatability of the assessment of anteroposterior curvatures of the spine using Saunders digital inclinometer

INTRODUCTION

According to the requirements of Evidence Based Medicine, every research tool and method should be subjected to reliability evaluation. A variety of inclinometers are used for the assessment of sagittal plane spinal curvatures in clinical practice. The aim of the study was to evaluate the intra- and interobserver repeatability of measurements of the anterior-posterior spinal curvatures taken with Saunders digital inclinometer.

MATERIAL AND METHODS

The study involved 30 healthy subjects (5 males, 25 females) aged 20 to 35 years. The anteroposterior curvatures of the spine were measured in all subjects using a Saunders digital inclinometer. In order to evaluate the intraobserver repeatability of measurements, the results obtained by one investigator were compared. To evaluate interobserver repeatability, the results obtained by three investigators were compared. Additionally, the levels of reliability and measurement error were determined.

RESULTS

The measurements conducted by one investigator showed good repeatability for sacral slope, lumbar lordosis, and thoracic kyphosis, including the angle of proximal (Th1-Th6) and distal (Th6-Th12) thoracic kyphosis (p>0.05). For measurements taken by three investigators, interobserver repeatability was achieved for thoracic kyphosis (p>0.05). The reliability of the measurements was good (Cronbach's alpha was 0.9> α ≥0.8), and the measurement error was between 2.8°-3.8°.

CONCLUSIONS

The assessment of anteroposterior curvatures of the spine by one investigator provided good repeatability and reliability of measurements. Measurements performed by more than one investigator displayed partial repeatability. The value of the observational error should be taken into account in the interpretation of results of measurements performed with the Saunders inclinometer. The assessment of anteroposterior curvatures of the spine should be preceded by a verification of measurement reliability.

Expandable titanium cages for thoracolumbar vertebral body replacement: initial clinical experience and review of the literature

Reconstruction of the anterior and middle column after vertebrectomy is essential for restoring stability. Use of expandable implants is supported by an emerging body of literature. Newer expandable cages have some advantages over traditional mesh implants, structural allograft, and polyetheretherketone or carbon fiber cages. To determine the utility of an expandable titanium cage in spine reconstruction, we conducted a retrospective cohort study of patients who had undergone this reconstruction after single or multilevel thoracic and/or lumbar vertebrectomy. Here we report on our experience using expandable cages at 2 large academic medical centers. Outcome was based on both clinical and radiographic measures with cross-sectional analysis. Thirty-five patients were identified. Of these, 20 had undergone surgery for neoplasm, 8 for trauma, and 7 for infection. Mean follow-up was 31 months (range, 12 to 50 months). Early postoperative kyphosis correction, restoration of sagittal alignment at 12 months, and reduction in visual analog scale pain score were significant. There was no difference in Oswestry Disability Index or height restoration. Expandable intervertebral body strut grafts appear to be a safe and effective option in spine reconstruction after a vertebrectomy and should be considered a treatment option.

Recurrent epithelioid sarcoma in the thoracic spine successfully treated with multilevel total en bloc spondylectomy

Epithelioid sarcoma (ES) is a rare type of soft tissue tumor. The common location of ES is at the extremities and rarely occurs in axial skeleton. Only two cases have been reported so far. Initial wide resection is recommended for the treatment of ES. However, the local recurrent rate is high and repeat surgical resection is still an option for the treatment of the recurrent. In the spine, however, the proper treatment of recurrent ES has not yet been published. Therefore, the objective of this case report is to illustrate the management strategies for the local recurrent ES after initial surgical resection in the thoracic spine. A 14-year-old boy was diagnosed for ES in the thoracic spine for 2 years. He was first treated by surgical resection followed by the chemotherapy and radiotherapy but the disease had progressed and the spine was gradually deformed. He was admitted to our facility with a large soft tissue mass, severe kyphotic deformity and neurological deficit. We removed the tumor en bloc by one-stage posterior only approach. The posterior transpedicular spinal instrumentation and fibular strut graft were used for the reconstruction. On the last follow-up, 2 year after the surgery, the patient remained in good condition. In conclusion, the recurrent ES of the spine can still archive a good oncological outcome with repeat radical resection, but the initial radical resection remains the best treatment option in order to retard the relentless course of this kind of malignancy.

Age-related hyperkyphosis, independent of spinal osteoporosis, is associated with impaired mobility in older community-dwelling women

While many assume hyperkyphosis reflects underlying spinal osteoporosis and vertebral fractures, our results suggest hyperkyphosis is independently associated with decreased mobility. Hyperyphosis is associated with slower Timed Up and Go performance times and may be a useful clinical marker signaling the need for evaluation of vertebral fracture and falling risk.

INTRODUCTION

While multiple studies have demonstrated negative effects of hyperkyphosis on physical function, none have disentangled the relationship between hyperkyphosis, impaired function, and underlying spinal osteoporosis. The purpose of this study is to determine whether kyphosis, independent of spinal osteoporosis, is associated with mobility on the Timed Up and Go, and to quantify effects of other factors contributing to impaired mobility.

METHODS

We used data for 3,108 community-dwelling women aged 55-80 years in the Fracture Intervention Trial. All participants had measurements of kyphosis, mobility time on the Timed Up and Go test, height, weight, total hip bone mineral density (BMD), grip strength, and vertebral fractures at baseline visits in 1993. Demographic characteristics included age and smoking status. We calculated mean Timed Up and Go time by quartile of kyphosis. Using multivariate linear regression, we estimated the independent association of kyphosis with mobility time, and quantified effects of other covariates on mobility.

RESULTS

Mean mobility time increased from 9.3 s in the lowest to 10.1 s in the highest quartile of kyphosis. In a multivariate-adjusted model, mobility time increased 0.11 s (p = 0.02) for each standard deviation (11.9°) increase in kyphosis. Longer performance times were significantly associated with increasing age, decreasing grip strength, vertebral fractures, body mass index ≥25, and total hip BMD in the osteoporotic range.

CONCLUSIONS

Kyphosis angle is independently associated with decreased mobility on the Timed Up and Go, which is in turn correlated with increased fall risk. Hyperkyphosis may be a useful clinical marker signaling the need for evaluation of vertebral fracture and falling risk.

Relationship between kyphosis and Barrett's esophagus in Japanese patients

BACKGROUND

Kyphosis is a risk factor for the presence of hiatal hernia, which is a strong predictor of Barrett's esophagus. However, the association between kyphosis and Barrett's esophagus has not yet been clarified. To investigate this relationship, the Cobb angle, a marker of kyphosis, was measured in patients with and without Barrett's esophagus.

METHODS

From January 2006 to December 2010, 26 patients with long-segment Barrett's esophagus (LSBE) were retrospectively enrolled. As the comparative groups, 100 consecutive patients with short-segment Barrett's esophagus (SSBE) and 100 consecutive control patients without Barrett's esophagus were also enrolled in this study. Cobb angles were measured on lateral chest radiographs, and kyphosis was defined as a Cobb angle of greater than 50°. Kyphosis, along with other patient characteristics, were evaluated as possible predictors for SSBE and LSBE.

RESULTS

The mean Cobb angles in the non-BE, SSBE, and LSBE groups were 31.6° (95% CIs, 29.3°-33.9°), 34.8° (32.1°-37.4°) and 49.4° (44.9°-53.9°), respectively. Statistically significant differences were found between the LSBE and the other 2 groups (p<0.001). The mean Cobb angles were 33.3°±12.4° and 37.0°±14.1°, respectively in patients without and with hiatal hernia (p=0.039). Predictors for Barrett's esophagus of any length were erosive esophagitis and hiatal hernia. Kyphosis had the highest odds ratio for the presence of LSBE (OR, 1.50; 95% CI, 1.05-1.94; p=0.033). Other predictors were hiatal hernia and the absence of Helicobacter pylori infection.

CONCLUSION

Kyphosis is a risk factor for the presence of LSBE in Japanese patients.