Erect Radiographs Research Articles

Can We Screen for Limb Length Discrepancy on Spinal Radiographs of Patients With Adolescent Idiopathic Scoliosis?

The aim of this study was to determine whether height differences in the levels of the iliac crests and femoral heads on erect spinal radiographs can be used as indirect measurements for the screening and surveillance of limb length discrepancy (LLD) in patients with scoliosis. Whole body posteroanterior (PA) and lateral erect radiographs of patients with adolescent idiopathic scoliosis (AIS) were retrospectively reviewed. Patients with congenital, syndromic, and neuromuscular scoliosis were excluded. A direct measurement of each limb was taken from the highest point of the femoral head to the middle of the tibial plafond; any difference between the sides was recorded as the LLD. In addition, the PACS Software tool was used to measure femoral head height difference (FHHD) and iliac crest height difference (ICHD). Pearson's correlation, linear regression, and Bland-Altman plots were used to determine the relationships between LLD and FHHD, and LLD and ICHD. Radiographs of 141 patients (92 women, 49 men) with an average age of 12.0±2.65 years were analyzed. A strong correlation (r=0.730, P<0.001) was found between LLD and FHHD; the correlation between LLD and ICHD was weaker (r=0.585, P<0.001). The Bland-Altman analysis showed good agreements of LLD with FHHD and ICHD. Linear regression analysis predicted an LLD of ≤10mm based on an FHHD of ≤11.5mm or an ICHD of ≤15.3mm. FHHD and ICHD on spinal PA radiographs can be used for the screening and monitoring of LLD in patients with AIS with FHHD being the preferred indirect measurement. These measurements are readily learned and quick to perform. The FHHD and ICHD can be measured on any erect scoliosis PA radiograph. Therefore, these proxy measurements can be used to screen and monitor for LLD in patients with AIS. Level III.

Does levelling of T1 tilt intra-operatively affect post-operative shoulder balancein adolescent idiopathic scoliosis patients?

Previous studies have shown that T1 tilt is positively correlated with post-operative shoulder balance (SB). The aim of this study was to explore the role of intra-operative T1 tilt, among other shoulder parameters as a potential parameter to predict post-operative SB in adolescent idiopathic scoliosis (AIS) patients. A retrospective review of AIS patients with structural thoracic curves with minimum 2year follow up was conducted from a single tertiary center. Standing pre-operative, 1st erect, 1year and 2-year follow-up; and intra-operative final prone radiographs were reviewed along with clinical data. Patients were stratified into 2 cohorts: Group A-Final intra-operative T1 tilt ≤5° and Group B-Final intra-operative T1 tilt >5°. These groups were compared for post-operative SB as a whole and separately for patients with baseline right or left shoulder high and if UIV was T2 or T3/T4. Patients with optimal SB (Radiographic shoulder height (RSH) <2cm) at 2years were compared to sub-optimal SB (RSH ≥ 2cm) with respect to multiple SB variables. 55 patients (mean age 15.1years-old, 43 F, mean BMI 22, mean thoracic Cobb-49.8°) were included. Based on Lenke curve types, there were 13 patients with type 1A, 10 patients with 1B, 12 patients with 1C, 7 patients with 2A, 4 patients with 2B and 9 patients with type 3C. T1 tilt was significantly correlated with RSH, Clavicle angle difference (CAD), First Rib Angle (FRA), and UIV tilt at first erect, 1-year, and 2-year post-op radiographs (p < 0.05 for all). When comparing groups, A and B, Group A patients showed significantly better restoration of their 2-year SB parameters; RSH (6.8 vs 11.8mm, p = 0.01), CAD (3.9 vs 9.1 p < 0.001) and T1 tilt (4.7 vs 7.8° p = 0.01). Similar results were found for patients with baseline right shoulder high; RSH (p = 0.04), CAD (p < 0.001) and T1 tilt (p < 0.001) and whether UIV was T2 or T3/T4. Eight patients with sub-optimal SB had worse intra-operative T1 tilt (p = 0.03) compared to 47 patients with optimal SB despite no difference in MT Cobb correction (83.1 vs 79.8%, p = 0.57). Post-operative T1 tilt correlates with lateral shoulder parameters at first erect, 1year, and 2-year radiographs. Therefore, T1 tilt can potentially be used as a surrogate to predict post-operative SB. Leveling intra-operative T1 tilt ≤5° is associated with better 2-year post-operative shoulder balance parameters irrespective of whether the UIV was T2 or T3/T4. Patients with sub-optimal SB at 2years had worse final intra-operative T1 tilt despite similar percent correction of main thoracic curve for all patients.

Vertebral body tethering for Lenke 1A curves: the lumbar modifier predicts less optimal outcomes.

The addition of the L4 "AR" and "AL" lumbar modifier for Lenke 1A idiopathic scoliosis (IS) has been shown to direct treatment in posterior spinal fusion; however, its utility in vertebral body tethering (VBT) has yet to be evaluated. A review of a prospective, multicenter database for VBT in IS was performed for patients with Lenke 1A deformities and a minimum of 2years follow-up. Patients were categorized by their lumbar modifier (AR vs AL). Less optimal VBT outcome (LOVO) was defined as a final coronal curve > 35°, lumbar adding-on, or revision surgery for deformity progression or adding-on. Ninety-nine patients met inclusion criteria (81% female, mean 12.6years), with 55.6% being AL curves. Overall, there were 23 instances of tether breakage (23.3%) and 20 instances of LOVO (20.2%). There was a higher rate of LOVO in AR curves (31.8% vs 10.9%, P = 0.01). Patients with LOVO had greater preoperative deformity, greater apical translation, larger coronal deformity on first erect radiographs, and less coronal deformity correction. Failure to correct the deformity < 30° on first erect was associated with LOVO, as was LIV selection short of the last touch vertebra (TV). Independent risk factors for LOVO included AR curves (OR 3.4; P = 0.04) and first erect curve magnitudes > 30 degrees (OR 6.0; P = 0.002). There is a 20.2% rate of less optimal VBT following VBT for Lenke 1A curves. AR curves are independently predictive of less optimal outcomes following VBT and require close attention to LIV selection. Surgeons should consider achieving an initial coronal correction < 30 degrees and extending the LIV to at least the TV to minimize the risk of LOVO.

The Reliability of Measurements for Tibial Torsion: A Comparison of CT, MRI, Biplanar Radiography, and 3D Reconstructions With and Without Standardized Measurement Training

Background: Accurate and reliable assessment of tibial torsion is important for the identification and treatment of tibial rotation malalignment; however, the ideal rotational measurement modality and technique are controversial. This study compares rotational measurements between computed tomography (CT), magnetic resonance imaging (MRI), biplanar erect radiograph (BER) reconstructions, and three-dimensional (3D) reconstructed CT before and after standardized training of observers to evaluate the reliability of each assessment method.Methods: Eight adult cadaveric specimens underwent CT, MRI, and BER imaging. Tibial torsion was measured by three independent observers (one resident and two experienced orthopaedic surgeons) both before and after standardized measurement instruction. Reliability for inter-observer measurement was evaluated using the Intraclass Correlation Coefficient (ICC). Measurement values for CT, MRI, and BER reconstructions were compared to 3D CT reconstructions analyzed using custom software to align and measure tibial torsion (used as the reference standard).Results: Before training, there was poor inter-observer reliability for CT (ICC=0.492, p=0.014) and moderate interobserver reliability for MRI (ICC=0.633, p=0.002). There was no inter-method reliability between 3D CT and MRI for two of the three surgeons and moderate to good reliability between 3D CT and CT. After training, the interobserver reliability for CT improved to 0.536 and the inter-observer reliability for MRI improved to 0.701. The BER measurements (no observer involvement) had moderate reliability compared to the 3D CT reconstructions (ICC=0.69, p=0.026). Measurement error was 4 degrees for CT pre-training and 7 degrees post-training, and 7 degrees for MRI pre-training and 8 degrees post-training.Conclusions: A standardized training regimen for MRI measurements improved both inter-observer and intraobserver reliability. Inter-method reliability between CT, MRI, and BER compared to reference 3D CT reconstructions demonstrated that all imaging modalities are a valid means to measure tibial rotation but differ in reliability from moderate to good. When assessing tibial torsional deformities, it is important to consider these variations from true rotation and feel comfortable using them for pre-operative planning purposes.Level of Evidence: N/A for a cadaveric imaging study Key Concepts•A standardized training regimen for MRI measurements of tibial torsion significantly improved inter-observer and intra-observer reliability.•CT, MRI, and BER measurements are valid imaging modalities compared to 3D CT reference standards for measuring tibial rotation.•Established manual measurements of tibial torsion from MRI may be improved with adequate training.•Measurement error of up to 8 degrees can be seen from true tibial torsion during the imaging assessment.

Effects of distraction-based distal fixation on pelvic parameter development in early onset scoliosis.

Prior studies have suggested that distraction-based treatment for early onset scoliosis (EOS) may impede the natural development of the sagittal spinal alignment and pelvic parameters. However, to date no study has investigated the effect of distal fixation on pelvic development. Ambulatory children with EOS undergoing index distraction-based treatment with distal fixation below T11 were retrospectively reviewed. Patients with distal fixation to the pelvis were identified and compared to children with Spine-based fixation at T12-L5. Radiographic measurements were performed for coronal and sagittal alignment in addition to pelvic parameters (pelvic incidence (PI), pelvic tilt (PT), and sacral slope (SS) and compared at initial presentation, first erect radiograph, and at 2years following instrumentation. 33 ambulatory children were identified with a minimum of 2-year follow-up (25 female, average 6.59 ± 2.6years), with 33% (N = 11) instrumented to the pelvis (54.4% female, average 4.42 ± 2.2years, initial Cobb 76.1°). Children in the pelvis cohort were significantly younger at treatment initiation (P < 0.001). There was no significant difference in PI at the study time periods, however, there was a significant change in PI between presentation and 2-year follow-up with the pelvic fixation demonstrating a mean 12.3° decrease in PI vs a 3.8° increase in the spine-based cohort (P = 0.027). Distal fixation to the pelvis in ambulatory children with EOS treated with growth-friendly instrumentation was associated with a mean decrease in PI of 12.3° that developed over the 2-year treatment duration. Further research is needed to investigate the long-term implications of these findings on pelvic and spinal development.

Subcutaneous Fat Thickness on Erect Radiographs Is a Predictor of Infection Following Elective Posterior Lumbar Fusion.

Posterior lumbar fusions are a common and successful procedure, yet surgical site infection (SSI) is still prevalent and causes significant morbidity. Obesity is a well-established risk factor for SSI. Still, the accuracy of the body mass index (BMI) caused some to suggest other metrics that are more representative of the thickness of the soft-tissue envelope in the surgical site. A retrospective review of all cases that developed SSI following posterior lumbar fusion over the past 5 years was done. An age and gender-matched control group was formed from the lumbar fusion cases that did not develop SSI. Demographic and clinical data were collected, and morphometric measurements of the soft-tissue envelope were performed at the level of L4 for all cases on standing x-ray imaging and magnetic resonance imaging (MRI). A total of 366 patients underwent posterior lumbar fusion, 26 of whom developed SSI. BMI and skin to spinous process measurements on x-ray imaging-not MRI-were found to be significantly associated with SSI. Regression analysis further confirmed the strength of the association. While BMI and MRI measurements are useful, wound depth measurements on x-ray imaging can be predictive of SSI in lumbar fusion cases. Wound depth measurements are predictive of lumbar wound infection. The information within this study can help surgeons better predict and manage infections of posterior lumbar wounds.

Body mass index affects outcomes after vertebral body tethering surgery.

To compare the outcomes of anterior Vertebral Body Tethering (AVBT) surgery between overweight and non-overweight patients. AIS/JIS patients with AVBT with 2-year follow-up from a multi-center pediatric spine database were evaluated pre-operatively, 1st post-operative erect, and 2years post-operatively. ANOVA was used to compare 3 categories of BMI with significance as per Tukey-Kramer HSD post hoc test. Risk of scoliosis progression was analysed with Mid-P exact test. 121 patients (51 underweight, 58 normal, 12 overweight; mean age 12.5 ± 1.6yr; BMI 18.8 ± 4.6kg/m2) were identified. Comparing underweight, normal, and overweight groups: mean pre-operative age (13yr, 13yr, 12yr), scoliosis (52°, 50°, 52°), pre-operative kyphosis (29°, 28°, 33°), peri-operative scoliosis correction (44%, 42%, 46%), and complications by 2-year follow-up (23%, 24%, 17%) were similar between groups. There was one broken tether in each of the underweight and normal weight groups. Change in percent scoliosis correction from 1st erect to 2-year post-operative (i.e., growth modulation phase) was not significantly different between groups; however, the risk ratio for scoliosis progression during this period was 4.74 (1.02-22.02; p = 0.04) for overweight patients. Our findings demonstrate that, as compared to normal weight and underweight patients, overweight patients did not have a statistically significant difference in intra-operative scoliosis correction or in risk of experiencing complication; however, overweight patients had a risk ratio of 4.74 for progression of scoliosis during the growth modulation phase of treatment from first erect radiographs to minimum 2-year follow-up. III.

Pedicle Screw Plowing in Adolescent Idiopathic Scoliosis: How Common Is It and Is It a Problem?

Multicenter retrospective review. To calculate overall incidence of pedicle screw "plowing" in adolescent idiopathic scoliosis (AIS) patients who underwent posterior spinal fusion (PSF). To identify risk factors for pedicle screw plowing and associated postoperative outcomes, including loss of correction and revision rate. Curve correction of AIS generates perpendicular stresses that can cause pedicle screws to lose alignment and "plow" through pedicles craniocaudally. We reviewed records of 1057 patients who underwent PSF for AIS from 2002 to 2015. Preoperative and first postoperative erect radiographs were evaluated by two observers to determine (1) presence of plowing and (2) subsequent loss of correction (LOC). Plowing was defined as more than 25° sagittal angulation compared with pedicle axis or entry of the most dorsal part of the screw outside the pedicle projection. LOC was defined as postoperative change in focal angulation of an instrumented spinal level, when in consensus of both reviewers. Bivariate analyses were performed (alpha = 0.05). Nineteen thousand five hundred sixty nine screws were assessed across our cohort of 1057 patients. Both observers agreed that 48 patients (4.5%) demonstrated plowing of more than or equal to one pedicle screw. For 72 screws (0.4%), both observers noted plowing, most commonly through the cranial cortex of the pedicle (65/72 screws) and at the lowest instrument vertebra (LIV) (17/72 screws). Factors associated with plowing included larger curves (P = 0.02); lower mean pedicle screw density (P = 0.0003); skeletal immaturity as measured by open triradiate cartilage (P = 0.04); and younger chronological age at time of surgery (P = 0.04). LOC occurred in 13 patients, most commonly at LIV (P < 0.0001). Revision rate for loss of screw fixation was higher in the plowing group (P = 0.003). Pedicle screw plowing occurred in 4.5% of AIS patients, especially in those skeletally immature and with decreased implant density. Plowing commonly occurred in the cranial direction and was associated with LOC, particularly at the LIV.Level of Evidence: 3.

Can We Stop Distally at LSTV-1 for Adolescent Idiopathic Scoliosis With Lenke 1A/2A Curves?

A retrospective study. To determine in which case one level proximal to last substantially touching vertebra (LSTV-1) could be a valid lowest instrumented vertebra (LIV), in which case distal fusion should extend to last substantially touching vertebra (LSTV), and to identify risk factors for distal adding-on. Posterior thoracic fusion to save more lumbar mobile segments has become the mainstay of operative treatment for adolescent idiopathic scoliosis (AIS) with Lenke 1A/2A curves. Although previous studies have recommended selecting the LSTV as LIV, good outcomes could still be achieved in some cases when LSTV-1 was selected as LIV. Ninety-four patients were included in the study with a minimum of 2-year follow-up after posterior thoracic instrumentation, in which LSTV-1 was selected as LIV. Patients were identified with distal adding-on between first erect radiographs and 2-year follow-up based on previously defined parameters. Factors associated with the incidence of adding-on were analyzed. The mean follow-up duration was 37.7 ± 15.8 months. Forty patients (42.6%) with LSTV-1 selected as LIV achieved good outcomes at the last follow-up. Several preoperative risk factors significantly associated with distal adding-on were identified, including lower Risser (P = 0.001), longer thoracic curve length (P = 0.005), larger rotation and deviation of LSTV-1 (P < 0.001), and preoperative coronal imbalance (P = 0.013). Skeletally immature patients with long thoracic curve, preoperative coronal imbalance, large rotation, and deviation of LSTV-1 are at increased risk of distal adding-on when selecting LSTV-1 as LIV. Under this condition, distal fusion level should extend to LSTV; while in other case, LSTV-1 could be a valid LIV.Level of Evidence: 4.

Anterior Vertebral Body Tethering for Treatment of Idiopathic Scoliosis in the Skeletally Immature: Results of 112 Cases.

Prospective case series. Determine the efficacy of anterior vertebral body tethering (AVBT) in skeletally immature patients. The value of AVBT is currently unclear given the paucity of available data. Consecutive skeletally immature patients with idiopathic scoliosis were treated with AVBT between 2012 and 2018 by one of two surgeons working at two independent centers and followed up for >2 years. Data were collected prospectively and supplemented retrospectively where necessary. Outcomes were measured preoperatively, at first erect radiograph (FE), 1-year postoperatively and at most recent follow up (FU). One hundred twelve patients underwent 116 primary tethering procedures (108 thoracic and eight lumbar tethers). Four patients had primary tethering of both lumbar and thoracic curves. At surgery mean age was 12.7 ± 1.4 years (8.2-16.7) and Risser 0.5 ± 0.9 (0-3). Follow up was mean 37 ± 9 months (15-64). Preoperative mean coronal Cobb angle of the 130 tethered curves was 50.8° ± 10.2 (31-81) and corrected significantly to 26.6° ± 10.1 (-3-61) at FE radiograph (P < 0.001). Further significant improvement was seen from FE to 1-year, to mean 23.1° ± 12.4 (-37-57) (P < 0.001). There was a small but significant increase between 1-year and FU to 25.7° ± 16.3 (-32-58) (P < 0.001), which appeared to reflect tether breakage. Untethered minor curves were corrected from 31.0° ± 9.5 (3-57) to 20.3° ± 10.3 (0-52) at FU (P < 0.001). Rib hump was corrected from 14.1 ± 4.8 (0-26) to 8.8° ± 5.4 (0-22) at FU (P < 0.01). Twenty-five patients (22%) had 28 complications. Fifteen patients (13%) requiring 18 revision operations including six completed and one awaited fusions. AVBT of immature cases is associated with satisfactory deformity correction in the majority of cases. However, complication and revision rates suggest the need for improved implants and patient selection. Long-term follow-up remains crucial to establish the true efficacy of this procedure.Level of Evidence: 3.

Does preoperative and intraoperative imaging for anterior vertebral body tethering predict postoperative correction?

Anterior vertebral body tethering (AVBT) is an emerging approach for idiopathic scoliosis. However, overcorrection and under-correction are common causes of revision surgery, and intraoperative tensioning of the cord is one key component to achieve appropriate curve correction. We sought to determine whether preoperative flexibility radiographs or intraoperative radiographs would predict correction at first erect imaging for scoliosis patients undergoing anterior vertebral body tethering (AVBT). Single-center retrospective review. Fifty-one patients with a diagnosis of idiopathic scoliosis underwent anterior body tethering. Preoperative flexibility films and intraoperative radiographs were compared to first erect standing radiographs to determine if there was a correlation in Cobb angle. Preoperative major Cobb angle measured 52° ± 9°. Major Cobb angle on bending films was 24° ± 8°. Intraoperative imaging showed correction to a mean of 17° ± 8°. Postoperative first erect standing radiographs showed correction to a mean of 26° ± 10°. The mean difference in major Cobb angle between intraoperative radiograph and a first erect radiograph was 10° ± 4°, whereas the mean difference from preoperative bending radiograph at first erect was 2° ± 7°. Thus, correction on preoperative flexibility films correlated with the first erect radiograph. Preoperative bending radiographs provide a reasonable estimate of postoperative correction for patients undergoing AVBT with tensioning of the cord. Surgeons should expect the major Cobb angle to increase on first erect radiographs compared to intraoperative radiographs. These findings may guide patient selection and assist surgeons in achieving appropriate correction intraoperatively.

Low lordosis is a common finding in young lumbar disc herniation patients

PurposeThe sagittal alignment of the lumbar spine and pelvis can be classified into several subtypes. It has been suggested that the risk of developing certain pathologies, such as a lumbar disc herniation (LDH) is affected by spinal sagittal profiles. The main aim of this study was to investigate the sagittal profile in young patients surgically treated for a lumbar disc herniation and if a discectomy would alter the sagittal parameters.MethodsSixteen active young patients (mean age 18.3 ± 3.2 SD) with a lumbar disc herniation having a discectomy were included. A classification according to Roussouly of the sagittal parameters was made by two senior spinal surgeons, both pre-operatively and post-operatively on radiographs. The distribution of sagittal parameters and spinopelvic profiles were analysed and compared to a previous established healthy normal population.ResultsThis series of active young patients with LDH exhibited a low lumbar lordosis dominance, with Roussouly sagittal profiles type 1 and type 2 accounting for more than 75% of the examined patients. An analysis of the erect radiographs revealed no significant changes in the post-operative sagittal profile.ConclusionsThis study showed that sagittal spinal alignment according to Roussouly in a young population with LDH is skewed compared with a normal population cohort. Furthermore, the lack of post-operative correction is suggestive of a non-ephemeral response to a LDH. Roussouly type 2 spinal sagittal profile may be a risk factor in young individuals suffering a disc herniation.

Are postoperative standing radiographs relevant before hospital discharge in adolescent idiopathic scoliosis?

Postoperative standing radiographs are usually performed before hospital discharge after AIS fusion. However, patients are often still painful and have not recovered yet their physiological balance. The aim of this study was therefore to evaluate the relevance of such early radiographs and more specifically investigate whether postoperative alignment could be analyzed. All consecutive AIS patients operated between January 2015 and December 2015 were included. All patients underwent biplanar stereoradiographs before hospital discharge, at 4months postoperative and at last follow-up. Fifteen parameters (eight coronal and seven sagittal), reflecting correction and spinal alignment were measured and compared. The incidence of implant misplacement, requiring or not surgical revision, was recorded. In total, 100 patients were included. A significant difference was found for 12 out of the 15 (80%) parameters between the first erect radiograph and the 4-month follow-up visit, including the CVA and the SVA, which are commonly used to assess postoperative alignment. Clavicle, UIV and LIV tilts also decreased significantly at 4months postoperative. In opposition, no significant change occurred for the same parameters between the 4-month visit and latest follow-up. In nine patients, a pedicle screw was considered misplaced on the first radiograph, but all patients remained asymptomatic and no revision was performed. There is no need for additional immediate postoperative radiographs in AIS, if an intraoperative radiograph has already been taken. This finding could help reducing radiation exposure in immature patients and should be further studied in other etiologies. These slides can be retrieved under Electronic Supplementary Material.

Minimally invasive stabilization for thoracolumbar and lumbar fractures: a comparative study with short segment open Schanz screw constructs.

Analysis was performed of two patient cohorts who underwent fixation without fusion for unstable thoracolumbar and lumbar fractures: (I) minimally invasive surgery (MIS) group using combined monoaxial-polyaxial pedicle screws inserted percutaneously; (II) open surgery (OS) group using Schanz screw constructs. Our aim was to compare radiographic and clinical indices of the 'gold standard' of open Schanz screw to MIS monoaxial-polyaxial screw constructs. There were 13 patients in the MIS group and 19 in the OS group. Primary outcomes were the correction of fracture angulation and percentage loss of reduction until fracture union. Patient demographics, fracture classification, perioperative data and complications were also collected. There was no significant difference in cohorts when comparing demographics and fracture classification. Operative time was 50 minutes less and haemoglobin drop was 9 g/L less in the MIS group. Radiation exposure was significantly higher in the MIS group. Pre-operatively, the mean kyphotic angle was 22° in the MIS and 16° in the OS group. Both groups achieved similar on-table correction. On immediate postoperative erect radiographs, the MIS group lost 15% of correction vs. 55% in the OS group. At final follow-up, both groups had a further loss of position, but significantly higher in the OS group (28% vs. 96%). Combined polyaxial-monoaxial screw MIS constructs demonstrate favorable radiological and clinical outcomes for treatment of unstable thoracolumbar and lumbar fractures. Our study also demonstrates higher rates of radiological collapse in the OS cohort.

The value of the erect abdominal radiograph for the diagnosis of mechanical bowel obstruction and paralytic ileus in adults presenting with acute abdominal pain.

IntroductionThere is discord on the value of the erect abdominal radiograph for diagnosing acute abdominal pathologies. The erect radiograph can be uncomfortable for patients in pain and increases patient radiation dose.AimTo determine if including the erect abdominal radiograph in plain abdominal radiography (PAR) improved diagnostic accuracy for identifying mechanical bowel obstruction and/or paralytic ileus in adults presenting with acute abdominal pain.Methods PAR of 40 consecutive adults presenting with suspected bowel obstruction or paralytic ileus was retrospectively sampled and independently reviewed by two emergency department (ED) consultants and two radiology consultants for bowel obstruction and paralytic ileus across two sessions. In session 1, the assessors assessed the supine abdominal radiographs (PAR 1) and clinical details in a randomised order, and session 2, at least 6 weeks later, they assessed the supine and erect radiographs (PAR 2) and clinical details of the randomly re‐ordered cases. Computed tomography was the reference standard. Pair‐wise comparisons of receiver operating characteristic curves were calculated to assess for significant differences in participants’ diagnostic accuracy using MedCalc 16.4.3.ResultsAverage sensitivity, specificity and area under the receiver operating characteristic curves (AUROC) were 69.7%, 61.0% and 0.642 for PAR 1, respectively, and 80.0%, 53.4% and 0.632 for PAR 2 respectively. For AUROC there were no significant differences (P > 0.05) between PAR 1 and PAR 2. Intra‐rater and inter‐rater agreement improved in PAR 2.ConclusionThere was no statistically significant improvement in diagnostic accuracy when including the erect radiograph in PAR for the acute abdomen.

The Use of Tubular Retractors for Translaminar Discectomy for Cranially and Caudally Extruded Discs.

Background:The conventional interlaminar approach is adequate for access to most disc herniations in lumbar spine surgery. The access to cranially and caudally migrated disc fragments, by conventional interlaminar fenestration, requires an extension of the fenestration with the potential destruction of the facet joint complex and consequent postsurgical instability. To describe the technique and results of the translaminar technique of targeted discectomy using tubular retractors for the surgical treatment of cranially and caudally extruded discs.Materials and Methods:The study period extended from January 2008 to December 2014. All patients with lumbar herniated discs who failed conservative management were selected for surgery and underwent routine erect radiographs and magnetic resonance imaging (MRI) of the lumbar spine. The patients with cranially or caudally migrated discs were included in this study. The technique involves approaching migrated disc through an oval window (sculpted through an 18 mm tubular retractor using a burr) in the lamina precisely over the location of the migrated disc as predicted by the preoperative MRI (inferior lamina for inferior migration and superior lamina for superior migration). The perioperative parameters studied were operative time, blood loss, complications, Oswestry Disability Index (ODI), and visual analog scale (VAS) for leg pain before surgery and at last followup. In the study, 4 patients underwent a postoperative computed tomography-scan with a three-dimensional reconstruction to visualize the oval window and to rule out any pars fracture. All technical difficulties and complications were analyzed.Results:17 patients in the age group of 41–58 years underwent the translaminar technique of targeted discectomy. The migration of disc was cranial in 12 patients and caudal in 5 patients. Fourteen of the affected discs were at the L4–L5 level and three were at the L5-S1 level. The mean VAS (leg pain) scale improved from 8 to 1 and the mean ODI changed from 59.8 to 23.6. There were no intraoperative or postoperative complications encountered in this study. Furthermore, no patient in the present study required a conventional laminotomy or medial facetectomy. There was no evidence of iatrogenic pars injury or instability at the last followup. There were no recurrences till the last followup.Conclusions:The targeted translaminar approach preserves structures important for segmental spinal stability thus causing minimal anatomical disruption. This approach allows access to the extruded disc fragment and intervertebral disc space comparable to classical approaches.

VEPTR Implantation to Treat Children With Early-Onset Scoliosis Without Rib Abnormalities: Early Results From a Prospective Multicenter Study.

Thoracoplasty and insertion of vertical expandable prosthetic titanium rib (VEPTR) for thoracic and spine distraction has been found to be effective in the treatment of early-onset scoliosis (EOS) with ribs anomalies and congenital vertebral anomalies. The aim of this study was to evaluate the efficacy of VEPTR in preventing further progression of scoliosis without impeding spinal growth in children with progressive EOS without rib abnormalities. This is a prospective, multicenter, observational cohort study. Erect radiographs were analyzed for coronal and sagittal curve and height measurements at preimplant, immediate postoperative, and at 2-year follow-up. Sixty-three patients met inclusion: 35 males and 28 females. Mean age at time of implantation was 6.1±2.4 years. Etiologies included congenital (n=6), neuromuscular (n=36), syndromic (n=4), and idiopathic (n=17). The mean follow-up was 2.2±0.4 years. Scoliosis (72±18 degrees) decreased after implant surgery (47±17 degrees) followed by slight increase at 2-year follow-up (57±18 degrees), P<0.0001. Kyphosis (48±22 degrees) also showed significant decrease after implantation (40±14 degrees), but increased after 2 years (48±16 degrees), P<0.0001. Coronal spine height measurements including T1-T12 (15.7±3 cm) and T1-S1 (25±6 cm) showed significant increases after implantation surgery (17.7±4 cm and 28.6±6 cm, respectively) and at 2 years (18.4±4 cm and 29.1±5 cm, respectively), P<0.0001. The increase in coronal spine height represented 144% of expected age-matched T1-T12 growth and 193% of expected age-matched T1-S1 growth. Similarly, sagittal spine length of T1-T12 and T1-S1 increased from 16.9±2.7 cm and 27.1±3.9 cm, respectively preoperatively to 19.7±3.5 cm and 31.9±5.1 cm, respectively at 2-year follow-up, P<0.0001. The instrumented spine segment continued growth from 25.8±5.2 cm after implantation to 27.4±5.3 cm at 2-year follow-up, P<0.0001. Thirty-one patients (49%) had at least 1 complication with total of 58 complications. At 2-year follow-up, VEPTR was effective in treating EOS without rib abnormalities with 86% of patients having an improvement in scoliosis and 94% of patients having an increased spinal height as compared with preoperative values. This study proved that spine continues to grow after VEPTR instrumentation during the distraction phase. This amount of growth represents about 40% for T1-T12 and 31% for T1-S1 spine of the expected age-matched growth based on Dimeglio reference numbers. We find this growth important as it proves continuous spine growth with VEPTR treatment. Level II.

Predictors of Distal Adding-on in Thoracic Major Curves With AR Lumbar Modifiers.

Retrospective review of prospectively collected data. To determine whether the last substantially touched vertebra (LSTV) is a valid lowest instrumented vertebra (LIV) for both Lenke 1 and 2 curve patterns with AR lumbar modifiers, and to identify preoperative risk factors of distal adding-on. Previous studies have recommended selecting the LSTV as the LIV for Lenke 1AR curves (main thoracic curve with A lumbar modifier and L4 tilt to the right (thoracic overhang/King type IV curve). One-hundred sixty patients with a Lenke 1 or 2 curve pattern and AR lumbar modifier who underwent posterior spinal fusion between 2008 and 2012 were reviewed. All patients had minimum 2-year follow up. Patients were identified with distal adding-on between first erect radiographs and 2-year follow up based on previously defined parameters. Factors predictive of the adding-on phenomenon were identified in a multivariate binary logistic regression model. Twenty-seven patients (17%) were identified as having distal adding-on of their primary thoracic curve; however, only 8 of 89 patients (9%) fused to the LSTV developed adding-on (P = 0.005). Three variables were found to be significant predictors of adding-on: LIV proximal to LSTV (odds ratio, OR 3.63; P = 0.01), Risser zero (OR 4.93; P = 0.02), and C7-CSVL distance <2 cm (OR 3.97; P = 0.01). The risk of adding-on increased as the number of predictors increased from 16% with one risk factor to 80% when all three preoperative risk factors were present (P < 0.001). Choosing the LSTV as the LIV in Lenke 1 and 2 curve patterns with an AR lumbar modifier significantly decreases the risk of distal adding-on. Skeletally immature patients, those fused short of LSTV, and those with relative coronal balance preoperatively are at increased risk of distal adding-on between the initial postoperative visit and 2-year follow up. 4.

The efficacy of sagittal cervical spine subtyping: Investigating radiological classification methods within 150 asymptomatic participants.

Aims:The aim of this study is to (1) compare and contrast cervical subtype classification methods within an asymptomatic population, and (2) identify inter-methodological consistencies and describe examples of inconsistencies that have the potential to affect subtype classification and clinical decision-making.Methods:A total of 150 asymptomatic 18–30-year-old participants met the strict inclusion criteria. An erect neutral lateral radiograph was obtained using standard procedures. The Centroid, modified Takeshima/Herbst methods and the relative rotation angles in cases of nonagreement were used to determine subtype classifications. Cohen's kappa coefficient (κ) was used to assess the level of agreement between the two methods.Results:Nonlordotic classifications represented 66% of the cohort. Subtype classification identified the cohort as, lordosis (51), straight (37), global kyphosis (30), sigmoidal (13), and reverse sigmoidal (RS) (19). Cohen's kappa coefficient indicated that there was only a moderate level of agreement between methods (κ = 0.531). Methodological agreement tended to be higher within the lordotic and global kyphotic subtypes whereas, straight, sigmoidal, and RS subtypes demonstrated less agreement.Conclusion:This is the first study of its type to compare and contrast cervical classification methods. Subtypes displaying predominantly extended or flexed segments demonstrated higher levels of agreement. Our findings highlight the need for establishing a standardized multi-method approach to classify sagittal cervical subtypes.

T9 versus T10 as the upper instrumented vertebra for correction of adult deformity—rationale and recommendations

Background ContextAdult spinal deformity correction sometimes involves long posterior pedicle screw constructs extending from the lumbosacral spine to the thoracic vertebra. As fusion obliterates motion and places supraphysiological stress on adjacent spinal segments, it is crucial to ascertain the ideal upper instrumented vertebra (UIV) to minimize risk of proximal junctional failure (PJF). The T10 vertebra is often chosen to allow bridging of the thoracolumbar junction into the immobile thoracic vertebrae on the basis that it is the lowest immobile thoracic vertebra strut by the rib cage. PurposeThis study aimed to characterize the range of motion (ROM) of each vertebral segment from T7 to S1 to determine if T10 is truly the lowest immobile thoracic vertebra. Study Design/SettingThis is a prospective, comparative study. Patient SampleSeventy-nine adults (mean age of 45.4 years) presenting with low back pain or lower limb radiculopathy or both, without previous spinal intervention, metastases, fractures, infection, or congenital deformities of the spine, were included in the study. Outcome MeasuresA ROM >5° across two vertebral segments as determined by the Cobb method from radiographs. MethodsLumbar flexion-extension and neutral erect radiographs were obtained in randomized order using a slot scanner. Segmental ROM was measured from T7–T8 to L5–S1 and analyzed for significant differences using t tests. Age, gender, radiographical indices such as standard spinopelvic parameters, sagittal vertical axis (SVA), C7–T12 SVA, T1 slope, thoracic kyphosis (TK), and lumbar lordosis (LL) were studied via multivariate analysis to identify predictive factors for >5° change in ROM at the various segmental levels. There were no sources of funding and no conflicts of interest associated with this study. ResultsIn the thoracolumbar spine, significant decreases in ROM when compared with the adjacent caudad segment occurs up to T9–T10, with mean total ROM of 1.98±1.47° (p<.001) seen in T9–T10, 2.19±1.67° (p<.001) in T10–T11, and 3.92±3.21°(p<.001) in T11–T12. The total ROM of T8–T9 (2.53±1.79°) was not significantly different from that of T9–T10 (p=.261). At the thoracolumbar junction, absence of scoliosis (OR 11.37, p=.020), high pelvic incidence (OR 1.14, p=.046), and low T1 slope (OR 1.45, p=.030) were predictive of ROM >5°. ConclusionsLumbar spine flexion-extension ROM decreases as it approaches the thoracolumbar junction. T10 is indeed the lowest immobile thoracic vertebra strut by the rib cage, and the last significant decrease in ROM is observed at T9–T10, in relation to T10–T11. However, because this also implies that a UIV of T10 would mean there is only one level of fixation above the relatively mobile segment, while respecting other factors that influence UIV selection, we propose the T9 vertebra as a more ideal UIV to fulfill the biomechanical concept of bridge fixation. However, this decision should still be taken on a case-by-case basis.