To determine extent of correction in spinal osteotomy for fixed sagittal plane deformity. Radiographic retrospective cohort analysis using standardised standing whole spine radiographs. Level III evidence. 24 patients (14 females/10 males, av. 53.6 yrs) with sagittal plane deformity due to either ankylosing spondylitis (4), idiopathic (12), congenital (1), tumour (2), infectious (1), or posttraumatic (4) aetiologies. Max. 4 yrs follow up. Sagittal balance, lumbar lordosis correction, osteotomy angle, pelvic indices. Chevron (3), pedicle subtraction (17), and vertebral column resection (4) osteotomies were performed with the majority at L3 (9) and L2 (8). The C7-S1 sagittal vertical axis demonstrated a preoperative decompensation averaging 12.0 cm (range -7 to 37) with 55% of patients achieving normal sagittal balance postoperatively. Lumbar lordosis increased from 28.9° (range -28 to 63) to 48.9° (range 12 to 69) (22.3° av. correction). L3 osteotomy angle was largest, average 31° (range, 16 to 47). There were 11 complications comprising; major (1) and minor (1) neurological, junctional kyphosis (3), metalwork problems (2), dural tear (2) and infection (2). Four patients required additional surgery at latest follow-up. Technical outcome was good 11(50%), fair 8(36%), poor 3(14%). Spinal osteotomy is a very effective technique to correct fixed sagittal imbalance and provide biomechanical stability. The high complication rate mandates a careful assessment of the risk/benefit ratio before undertaking what is a major reconstructive procedure. Most patients are satisfied, particularly when sagittal balance is achieved

The footplate in the current available TDR is flat without any allowance for endplate concavity in the sagittal plane. To assess the morphology of the endplates of the lower lumbosacral in the sagittal plane, and to identify the frequently occurring shape patterns of the end plates at each level. Retrospective Study. 200 consecutive magnetic reasonance imaging (MRI) scans of patients between the age of 30 and 60 years were analysed. In each endplate, the anteroposterior width, the height of concavity of the endplate, and the distance of the summit from the anterior vertebral body margin were noted. The shape of the endplate was noted as oblong (o) if the curve was uniform starting from the anterior margin and finishing at the posterior margin, eccentric (e) if the curve started after a flat portion at the anterior border and then curving backwards, and flat (f) if there is no curve in the sagittal plane. The shape of the end plate is mostly oblong at L3 IEP(59%), equally distributed between oblong and eccentric at L4 SEP (o=43.5%, e=46.5%), eccentric at L4 IEP (e=62.5%), eccentric at L5 SEP (e = 59.0%), eccentric at L5 IEP (e=94.0%), and flat at S1 SEP (f=82.5%). As there is a difference in the shape of the endplate at each level and they are not uniform, there is a need to focus on the sagittal shape of the footplate to avoid subsidence and mismatch of the footplate in cases of endplate concavity

To assess the clinical and radiologic outcome of MM patients with thoracic spine involvement and concomitant pathologic sternal fractures with a resultant severe sagittal plane deformity. A prospective cohort study (n=391) was performed over a 7-year period at a national tertiary referral centre for the management of multiple myeloma with spinal involvement. Clinical, serological and pathologic variables, radiologic findings, treatment strategies and outcome measures were prospectively collected. Pre-treatment and post-treatment clinical outcome measures utilised included EQ-5D, VAS, ODI and RMD scoring systems. 13 MM patients presented with a severe symptomatic progressive sagittal plane deformity with a history of pathologic thoracic compression fractures and concomitant pathologic sternal fracture. All patients with concomitant sternal fractures displayed the radiographic features and spinopelvic parameters of positive sagittal malalignment and attempted clinical compensation. All patients had poor health related quality of life measures when assessed. Pathologic sternal fracture in a MM patient with thoracic compression fractures is a risk factor for the development of a severe thoracic kyphotic deformity and sagittal malalignment. This has been demonstrated to be associated with a very poor health related quality of life

To describe a staged surgical technique to correct significant progressive sagittal malalignment, without the need for 3-column osteotomy, in patients with prior long thoracolumbar instrumentation for scoliosis and to evaluate the radiographic and clinical outcome from this surgical strategy. A small cohort study (n=6) of patients with significant sagittal malalignment following extensive thoracolumbar instrumented fusions for scoliotic deformity. Radiographic parameters analysed included pelvic incidence, pelvic tilt, sacral slope, lumbar lordosis, thoracic kyphosis and sagittal vertical axis. Clinical outcome measures collected included EQ-5D, ODI, SRS 22 and VAS Pain Scores. 3 patients had 2-stage anterior release and instrumented fusion followed by a posterior instrumented fusion 3 patients with a large sagittal plane deformity had a 3-stage surgical technique. All patients achieved an excellent correction of sagittal alignment, with no surgical complications and excellent health related quality of life (HRQOL) outcome measures at follow-up. There was no symptomatic non-unions or implant failures including rod breakages. We present a safe and effective surgical strategy to treat the complex problem of progressive sagittal malalignment in the previously instrumented adult deformity patient, avoiding the need for 3-column osteotomies in the lumbar spine

Aims. The direct posterior approach with subperiosteal dissection of the paraspinal muscles from the vertebrae is considered to be the standard approach for the surgical treatment of adolescent idiopathic scoliosis (AIS). We investigated whether or not a minimally-invasive surgery (MIS) technique could offer improved results. Methods. Consecutive AIS patients treated with an MIS technique at two tertiary centres from June 2013 to March 2016 were retrospectively included. Preoperative patient deformity characteristics, perioperative parameters, power of deformity correction, and complications were studied. A total of 93 patients were included. The outcome of the first 25 patients and the latter 68 were compared as part of our safety analysis to examine the effect of the learning curve. Results. In the first 25 cases, with a mean follow-up of 5.6 years (standard deviation (SD) 0.4), the mean preoperative major Cobb angle was 57.6° (SD 9.8°) and significantly corrected to mean 15.4° (SD 5.6°, 73% curve correction). The mean preoperative T5-T12 was 26.2 (SD 12.8) and significantly increased to mean 32.9 (SD 8.3). Both frontal and sagittal plane correction was conserved two years after surgery. The rate of perioperative complications was 12% and three further complications occurred (three deep delayed infection). In the latter cases, 68 patients were included with a mean follow-up time of three years (SD 0.6). The mean preoperative major Cobb angle was 58.4° (SD 9.2°) and significantly corrected to mean 20.4° (SD 7.3°).The mean preoperative T5-T12 kyphosis was 26.6° (SD 12.8°) and was significantly increased to mean 31.4° (SD 8.3°). Both frontal and sagittal correction was conserved two years after surgery. The perioperative (30 day) complication rate was 1.4%. Two (2.9%) additional complications occurred in two patients. Conclusion. MIS for AIS is associated with a significant correction of spine deformity in the frontal and sagittal planes, together with low estimated blood loss and short length of stay. The perioperative complication rate seems to be lower compared with the standard open technique based on the literature data. The longer-term safety of MIS for AIS needs to be documented with a larger cohort and compared with the standard posterior approach. Cite this article: Bone Joint J 2020;102-B(4):506–512

Ventral screw osteosynthesis is a common surgical method for treating fractures of the odontoid peg, but there is still no consensus about the number and diameter of the screws to be used. The purpose of this study was to develop a more accurate measurement technique for the morphometry of the odontoid peg (dens axis) and to provide a recommendation for ventral screw osteosynthesis. Images of the cervical spine of 44 Caucasian patients, taken with a 64-line CT scanner, were evaluated using the measuring software MIMICS. All measurements were performed by two independent observers. Intraclass correlation coefficients were used to measure inter-rater variability. The mean length of the odontoid peg was 39.76 mm (. sd. 2.68). The mean screw entry angle α was 59.45° (. sd. 3.45). The mean angle between the screw and the ventral border of C2 was 13.18° (. sd. 2.70), the maximum possible mean converging angle of two screws was 20.35° (. sd. 3.24). The measurements were obtained at the level of 66% of the total odontoid peg length and showed mean values of 8.36 mm (. sd. 0.84) for the inner diameter in the sagittal plane and 7.35 mm (. sd. 0.97) in the coronal plane. The mean outer diameter of the odontoid peg was 12.88 mm (. sd. 0.91) in the sagittal plane and 11.77 mm (. sd. 1.09) in the coronal plane. The results measured at the level of 90% of the total odontoid peg length were a mean of 6.12 mm (. sd. 1.14) for the sagittal inner diameter and 5.50 mm (. sd. 1.05) for the coronal inner diameter. The mean outer diameter of the odontoid peg was 11.10 mm (. sd.  1.0) in the sagittal plane and 10.00 mm (. sd. 1.07) in the coronal plane. In order to calculate the necessary screw length using 3.5 mm cannulated screws, 1.5 mm should be added to the measured odontoid peg length when anatomical reduction seems possible. The cross-section of the odontoid peg is not circular but slightly elliptical, with a 10% greater diameter in the sagittal plane. In the majority of cases (70.5%) the odontoid peg offers enough room for two 3.5 mm cannulated cortical screws. Cite this article: Bone Joint J 2013;95-B:536–42

Aims. Significant correction of an adolescent idiopathic scoliosis in the coronal plane through a posterior approach is associated with hypokyphosis. Factors such as the magnitude of the preoperative coronal curve, the use of hooks, number of levels fused, preoperative kyphosis, screw density, and rod type have all been implicated. Maintaining the normal thoracic kyphosis is important as hypokyphosis is associated with proximal junctional failure (PJF) and early onset degeneration of the spine. The aim of this study was to determine if coronal correction per se was the most relevant factor in generating hypokyphosis. Methods. A total of 95 patients (87% female) with a median age of 14 years were included in our study. Pre- and postoperative radiographs were measured and the operative data including upper instrumented vertebra (UIV), lower instrumented vertebra (LIV), metal density, and thoracic flexibility noted. Further analysis of the post-surgical coronal outcome (group 1 < 60% correction and group 2 ≥ 60%) were studied for their association with the postoperative kyphosis in the sagittal plane using univariate and multivariate logistic regression. Results. Of the 95 patients, 71.6% (68) had a thoracic correction of > 60%. Most (97.8%) had metal density < 80%, while thoracic flexibility > 50% was found in 30.5% (29). Preoperative hypokyphosis (< 20°) was present in 25.3%. A postoperative thoracic hypokyphosis was four times more likely to occur in patients with thoracic correction ≥ 60% (odds ratio (OR) 4.08; p = 0.005), after adjusting for confounding variables. This association was not affected by metal density, thoracic flexibility, LIV, UIV, age, or sex. Conclusion. Our study supports the ‘essential lordosis’ hypothesis of Roaf and Dickson, i.e. with a greater ability to translate the apical vertebra towards the midline, there is a commensurate lengthening of the anterior column due to the vertebral wedging. Cite this article: Bone Joint J 2020;102-B(4):513–518

This prospective multicentre study was undertaken to determine segmental movement, disc height and sagittal alignment after total disc replacement (TDR) in the lumbosacral spine and to assess the correlation of biomechanical properties to clinical outcomes. A total of 173 patients with degenerative disc disease and low back pain for more than one year were randomised to receive either TDR or multidisciplinary rehabilitation (MDR). Segmental movement in the sagittal plane and disc height were measured using distortion compensated roentgen analysis (DCRA) comparing radiographs in active flexion and extension. Correlation analysis between the range of movement or disc height and patient-reported outcomes was performed in both groups. After two years, no significant change in movement in the sagittal plane was found in segments with TDR or between the two treatment groups. It remained the same or increased slightly in untreated segments in the TDR group and in this group there was a significant increase in disc height in the operated segments. There was no correlation between segmental movement or disc height and patient-reported outcomes in either group. In this study, insertion of an intervertebral disc prosthesis TDR did not increase movement in the sagittal plane and segmental movement did not correlate with patient-reported outcomes. This suggests that in the lumbar spine the movement preserving properties of TDR are not major determinants of clinical outcomes. Cite this article: Bone Joint J 2013;95-B:81–9

We determined the frequency, rate and extent of development of scoliosis (coronal plane deformity) in wheelchair-dependent patients with Duchenne muscular dystrophy (DMD) who were not receiving steroid treatment. We also assessed kyphosis and lordosis (sagittal plane deformity). The extent of scoliosis was assessed on sitting anteroposterior (AP) spinal radiographs in 88 consecutive non-ambulatory patients with DMD. Radiographs were studied from the time the patients became wheelchair-dependent until the time of spinal fusion, or the latest assessment if surgery was not undertaken. Progression was estimated using a longitudinal mixed-model regression analysis to handle repeated measurements. Scoliosis ≥ 10° occurred in 85 of 88 patients (97%), ≥ 20° in 78 of 88 (89%) and ≥ 30° in 66 of 88 patients (75%). The fitted longitudinal model revealed that time in a wheelchair was a highly significant predictor of the magnitude of the curve, independent of the age of the patient (p <  0.001). Scoliosis developed in virtually all DMD patients not receiving steroids once they became wheelchair-dependent, and the degree of deformity deteriorated over time. In general, scoliosis increased at a constant rate, beginning at the time of wheelchair-dependency (p < 0.001). In some there was no scoliosis for as long as three years after dependency, but scoliosis then developed and increased at a constant rate. Some patients showed a rapid increase in the rate of progression of the curve after a few years – the clinical phenomenon of a rapidly collapsing curve over a few months. A sagittal plane kyphotic deformity was seen in 37 of 60 patients (62%) with appropriate radiographs, with 23 (38%) showing lumbar lordosis (16 (27%) abnormal and seven (11%) normal). This study provides a baseline to assess the effects of steroids and other forms of treatment on the natural history of scoliosis in patients with DMD, and an approach to assessing spinal deformity in the coronal and sagittal planes in wheelchair-dependent patients with other neuromuscular disorders. Cite this article: Bone Joint J 2014;96-B:100–5

To evaluate the differences between spinopelvic parameters before and after sagittal malalignment correction and to assess the relationship between these radiologic parameters and clinical outcome scores. A prospective cohort study was performed over a 2-year period at a major tertiary referral centre for adult spinal deformity surgery. All consecutive patients requiring 2-stage corrective surgery were included (n=32). Radiographic parameters and clinical outcome measures were collected preoperatively and at 6 weeks, 6 months, 1 year and 2 years postoperatively. Radiographic parameters analysed included pelvic incidence, pelvic tilt, sacral slope, lumbar lordosis, thoracic kyphosis and sagittal vertical axis. Clinical outcome measures collected included EQ-5D, ODI, SRS 22 and VAS Pain Scores. Correction of sagittal malalignment was associated with significant improvements in HRQOL. Restoration of lumbar lordosis, pelvic tilt and sagittal vertical axis correlated with postoperative improvements in EQ-5D, ODI, SRS 22 and VAS Pain Scores at follow-up. This study demonstrates that the magnitude of sagittal plane correction correlates with the degree of clinical improvements in HRQOL. This further underlines the need for spinal surgeons to target complete sagittal plane deformity correction if they wish to achieve the highest rates of HRQOL benefit in patients with marked sagittal malalignment

To assess the effectiveness of unilateral sublaminar and concave rib tethering with convex rib resection through the period of peak growth in lambs. Morphometric growth data from 10 experimental Scottish Blackface sheep were compared to those from 5 control animals (no intervention) over 12 months. Standardized AP and Lateral radiographs were taken before and at monthly intervals after scoliosis creation. The Cobb angle was measured in the coronal and sagittal planes. Rotational mal-alignment was assessed by axial CT 7 months post surgery. In the supine position the control animals had no coronal plane deformity and a mean 5° lordosis (T4-T12). These figures did not alter with growth (doubling of body weight). Tethering (at age 5 weeks) produced an immediate scoliosis of 22±11° and a lordosis of 24±8° (means(sd). The degree of scoliosis was maintained over 7 months (at 20°) but lordosis increased (to 59±11°, p<0.01). There was an associated change in vertebral rotation. Surgery had no influence on rate of growth or animal development. Two animals died from Clostridium associated enterocolitis. There were no deaths associated with the surgical intervention. This ovine model gives a progressive spinal deformity in the sheep but primarily in the sagittal plane. This fact should be considered in studies designed to evaluate the effectiveness of surgical implants

The widespread use of MRI has revolutionised the diagnostic process for spinal disorders. A typical protocol for spinal MRI includes T1 and T2 weighted sequences in both axial and sagittal planes. While such an imaging protocol is appropriate to detect pathological processes in the vast majority of patients, a number of additional sequences and advanced techniques are emerging. The purpose of the article is to discuss both established techniques that are gaining popularity in the field of spinal imaging and to introduce some of the more novel ‘advanced’ MRI sequences with examples to highlight their potential uses. Cite this article: Bone Joint J 2015;97-B:1683–92

Purpose and background. Identifying features in nonspecific low back pain (NSLBP) subjects that distinguish them from controls, or for elucidating subgroups, has proved elusive. Yet these would be helpful to monitor progress, improve management, and understand the nature of the condition. Previous work using quantitative videofluoroscopy (QF) has indicated that the distribution of motion between lumbar intervertebral joints is more uneven in those with a history of NSLBP. However, there maybe other features of these complex motion patterns yet to be revealed. A multivariate analysis was therefore carried out to explore other possible differences. Methods and results. Intervertebral motion data of L2/3 to L4/5, from a previously published study was used. This examined 40 patients with NSLBP and 40 healthy controls, matched for gender, age and body mass index, who underwent passive recumbent QF in the coronal and sagittal planes. For each motion direction, principal components analysis was carried out and salient dimensions selected. Using a lower dimensional principal components (PC) representation, groups were compared using Hoteling's T test. Linear and quadratic discriminant analysis (LDA and QDA) was carried out using PC representations to examine group differences. The features most clearly distinguishing groups from the LDA was examined graphically. An analysis of the sensitivity of the results to the number of PC dimensions was carried out. The performance of the LDA and QDA classifiers were examined using leave-one-out cross-validation. Conclusions. Hotelling tests revealed significant differences between groups for right and left side-bending. This was confirmed by LDA and QDA. There was no clear difference in the performance of these classifiers and performance did not improve by including more than 4 PC dimensions. Visualisation of the LDA indicated that patients had relatively lower amplitude motion at L4/5, compensated by higher amplitude at L2/3/4. These results point to additional features of lumbar motion that differentiates NSLBP. No conflicts of interest. No funding obtained (however, the original study was funded by NIHR - CATCDRF09)

Aims

The aim of this study was to assess the accuracy of pedicle screw placement, as well as intraoperative factors, radiation exposure, and complication rates in adult patients with degenerative disorders of the thoracic and lumbar spines who have undergone robotic-navigated spinal surgery using a contemporary system.

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To report the development of the technique for minimally invasive lumbar decompression using robotic-assisted navigation.

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This systematic review aims to identify 3D predictors derived from biplanar reconstruction, and to describe current methods for improving curve prediction in patients with mild adolescent idiopathic scoliosis.

Purpose. To study the relationship between Zygoapophysial Joint Tropism and pathologic fractures affecting lumbar and thoracic vertebrae in elderly patients. Methods. The sagittal plane orientation of the Zygoapophysial joints (facets or ZAJ) of 324 vertebrae of 63 patients were measured on MRI scans, stratified into lumbar and thoracic, fractured and non-fractured, and then classified according to the presence of tropism. The correlation between tropism and fractures, demographics pertaining to age, spinal level, and morbidity were studied. Results. From the 415 ZAJ pairs studied, 23 were excluded because of insufficient imaging leaving 388 ZAJ pairs. In 155 Thoracic ZAJ pairs, there 92 with a fracture, 39% demonstrating tropism; and there were 63 with no fracture, 43% demonstrating tropism. In 237 Lumbar ZAJ pairs, there were 144 with a fracture, 73% demonstrating tropism; there were 93 with no fracture, 42% demonstrating tropism. Conclusion. Our study suggests a correlation between the emergence of pathological fractures in the spine and tropism which is statistically significant in the lumbar but not in the thoracic. The authors confirm that this abstract has not been previously published in whole or substantial part nor has it been presented previously at a national meeting. Conflicts of interest: No conflicts of interest. Sources of funding: No funding obtained

Aim:. To simplify sagittal plane spinal assessment by describing a single novel angle in the lumbar spine equivalent to the difference between pelvic incidence (PI) and lumbar lordosis (LL) and evaluate its reliability. Methods:. New sagittal modifiers in the classification of adult degenerative spinal deformity have been shown to be valid and reliable with the greatest variability being for pelvic incidence minus lumbar lordosis (PI-LL). This measurement can be simplified to a new angle (alpha) without the need to determine either PI or LL. This angle is between a line intersecting the bicoxofemoral centre and perpendicular to the L1 endplate (alpha line) and a line from the bicoxofemoral centre to the centre of the sacral endplate. Two readers graded 40 non-premarked cases twice each, approximately 1 week apart. Inter- and intra-rater variability and agreement were determined for PI-LL and alpha angle separately. Fleiss' kappa was used for reliability measures. Results:. Inter-rater kappa for PI-LL showed substantial reliability and alpha angle showed almost perfect agreement. Intra-rater kappa showed substantial reliability for PI-LL but almost perfect agreement for alpha angle across both readers. Discussion:. Alpha angle can be used as a surrogate for PI-LL and is easier and more reliable to measure. When PI=LL, alpha angle is 0, so the alpha line bisects the sacral plate. Conflict Of Interest Statement: No conflict of interest

Aim:. To establish whether there is a direct relationship between pelvic morphology and lumbar segmental angulation in the sagittal plane. Methods:. 40 lateral whole spine radiographs with normal sagittal profiles were reviewed. Pelvic incidence (PI), Lumbar Lordosis (LL), Thoracic Kyphosis (TK) and segmental angulation at each level from L1 to the sacrum were measured (from endplate to endplate) distinguishing the vertebral body and intervertebral disc contribution. Pearson correlation coefficients were used to analyse any relationship between pelvic parameters and segmental angulation. Results:. A strong correlation was found between pelvic incidence and total lumbar lordosis and angulation at cephalad lumbar segments (L12, L23 and L34) P<0.0001 with the increased lordosis primarily (four fifths on average) found at the intervertebral disc. The proportion of total lumbar lordosis contributed at L45 and L5S1 reduced as pelvic incidence increased (P<0.0001). Discussion:. PI can predict segmental angulation. Although the majority of lumbar lordosis is produced at L45 and L5S1, cephalad-lumbar segments sequentially become increasingly important as PI increases. This describes a continuum that allows segmental abnormalities to be identified when compensation in adjacent segments maintains normal total LL. It also paves the way for anatomical reconstruction in degenerative adult deformity based on pelvic morphology. Conflict Of Interest Statement: No conflict of interest

There is evidence that various anatomical structures have altered morphology with ageing, and anecdotal evidence of changing lumbar spinous process (LSP) morphology with age. This study aims to clarify the influence of age on LSP morphology, and on lumbar spine alignment. 200 CT scans of the abdomen were reformatted with bone windows allowing precise measurement of LSP dimensions and lumbar lordosis. Observers were blinded to patient demographics. Inter-observer reliability was confirmed. The smallest LSP is at L5. The male LSP is on average 2-3mm higher and 1mm wider than the female LSP. LSP height increases significantly with age at every level in the lumbar spine (P<10. -5. at L2). The LSPs increase in height by 2-5mm between 20-85 years of age (P<10. -6. ), which was as much as 31% at L5 (P<10. -8. ). Width increases proportionally more, by 3-4mm or greater than 50% at each lumbar level (P<10. -11. ). Lumbar lordosis decreases in relation to increasing LSP height (P<10. -4. ) but is independent of increasing LSP width (P=0.2). The height and width of the spinous processes increases with age. Increases in spinous process height are related to a loss of lumbar lordosis and may contribute to sagittal plane imbalance