Aims. The aim of this study was to evaluate the reliability and validity of a patient-specific algorithm which we developed for predicting changes in sagittal pelvic tilt after total hip arthroplasty (THA). Methods. This retrospective study included 143 patients who underwent 171 THAs between April 2019 and October 2020 and had full-body lateral radiographs preoperatively and at one year postoperatively. We measured the pelvic incidence (PI), the sagittal vertical axis (SVA), pelvic tilt, sacral slope (SS), lumbar lordosis (LL), and thoracic kyphosis to classify patients into types A, B1, B2, B3, and C. The change of pelvic tilt was predicted according to the normal range of SVA (0 mm to 50 mm) for types A, B1, B2, and B3, and based on the absolute value of one-third of the PI-LL mismatch for type C patients. The reliability of the classification of the patients and the prediction of the change of pelvic tilt were assessed using kappa values and intraclass correlation coefficients (ICCs), respectively. Validity was assessed using the overall mean error and mean absolute error (MAE) for the prediction of the change of pelvic tilt. Results. The kappa values were 0.927 (95% confidence interval (CI) 0.861 to 0.992) and 0.945 (95% CI 0.903 to 0.988) for the inter- and intraobserver reliabilities, respectively, and the ICCs ranged from 0.919 to 0.997. The overall mean error and MAE for the prediction of the change of pelvic tilt were -0.3° (SD 3.6°) and 2.8° (SD 2.4°), respectively. The overall absolute change of pelvic tilt was 5.0° (SD 4.1°). Pre- and postoperative values and changes in pelvic tilt, SVA, SS, and LL varied significantly among the five types of patient. Conclusion. We found that the proposed algorithm was reliable and valid for predicting the standing pelvic tilt after THA. Cite this article: Bone Joint J 2024;106-B(1):19–27

Aims. 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. Methods. A comprehensive search was conducted by three independent investigators on MEDLINE, PubMed, Web of Science, and Cochrane Library. Search terms included “adolescent idiopathic scoliosis”,“3D”, and “progression”. The inclusion and exclusion criteria were carefully defined to include clinical studies. Risk of bias was assessed with the Quality in Prognostic Studies tool (QUIPS) and Appraisal tool for Cross-Sectional Studies (AXIS), and level of evidence for each predictor was rated with the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) approach. In all, 915 publications were identified, with 377 articles subjected to full-text screening; overall, 31 articles were included. Results. Torsion index (TI) and apical vertebral rotation (AVR) were identified as accurate predictors of curve progression in early visits. Initial TI > 3.7° and AVR > 5.8° were predictive of curve progression. Thoracic hypokyphosis was inconsistently observed in progressive curves with weak evidence. While sagittal wedging was observed in mild curves, there is insufficient evidence for its correlation with curve progression. In curves with initial Cobb angle < 25°, Cobb angle was a poor predictor for future curve progression. Prediction accuracy was improved by incorporating serial reconstructions in stepwise layers. However, a lack of post-hoc analysis was identified in studies involving geometrical models. Conclusion. For patients with mild curves, TI and AVR were identified as predictors of curve progression, with TI > 3.7° and AVR > 5.8° found to be important thresholds. Cobb angle acts as a poor predictor in mild curves, and more investigations are required to assess thoracic kyphosis and wedging as predictors. Cumulative reconstruction of radiographs improves prediction accuracy. Comprehensive analysis between progressive and non-progressive curves is recommended to extract meaningful thresholds for clinical prognostication. Cite this article: Bone Jt Open 2024;5(3):243–251

Aims

The aim of this study was to review the current evidence surrounding curve type and morphology on curve progression risk in adolescent idiopathic scoliosis (AIS).

Clinically significant proximal junctional kyphosis (PJK) occurs in 20% of children treated with posterior distraction-based growth friendly surgery. In an effort to identify modifiable risk factors, it has been theorized biomechanically that low radius of curvature (ROC) implants (i.e., more curved rods) may increase post-operative thoracic kyphosis, and thus may pose a higher risk of developing PJK. We sought to test the hypothesis that EOS patients treated with low ROC (more curved rods) distraction-based treatment will have a greater risk of developing PJK as compared to those treated with high ROC (straighter) implants. This is a retrospective review of prospectively collected data obtained from a multi-centre EOS database on children treated with rib-based distraction with minimum 2-year follow-up. Variables of interest included: implant ROC at index (220 mm or 500 mm), patient age, pre-operative scoliosis, pre-operative kyphosis, and scoliosis etiology. In the literature, PJK has been defined as clinically significant if revision surgery with superior extension of the upper instrumented vertebrae was performed. In 148 scoliosis patients, there was a higher risk of clinically significant PJK with low ROC (more curved) rods (OR: 2.6 (95%CI 1.09-5.99), χ2 (1, n=148) = 4.8, p = 0.03). Patients had a mean pre-operative age of 5.3 years (4.6y 220 mm vs 6.2y 500 mm, p = 0.002). A logistic regression model was created with age as a confounding variable, but it was determined to be not significant (p = 0.6). Scoliosis etiologies included 52 neuromuscular, 52 congenital, 27 idiopathic, 17 syndromic with no significant differences in PJK risk between etiologies (p = 0.07). Overall, patients had pre-op scoliosis of 69° (67° 220mm vs 72° 500mm, p = 0.2), and kyphosis of 48° (45° 220mm vs 51° 500mm, p = 0.1). The change in thoracic kyphosis pre-operatively to final follow up (mean 4.0 ± 0.2 years) was higher in patients treated with 220 mm implants compared to 500 mm implants (220 mm: 7.5 ± 2.6° vs 500 mm: −4.0 ± 3.0°, p = 0.004). Use of low ROC (more curved) posterior distraction implants is associated with a significantly greater increase in thoracic kyphosis which likely led to a higher risk of developing clinically-significant PJK in EOS patients

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

Background. Improvement of Scheuermann's thoracic kyphosis in the growing spine with Milwaukee brace treatment has been reported. However, the role of brace treatment in Mb. Scheuermann is controversial. We report results of brace treatment by low profile scoliosis module with sternal shield. Indication. Thoracic kyphosis >55° or back pain and kyphosis >50°. Material. 21 consecutive patients (17 boys, 4 girls) referred to the Orton Orthopaedic Hospital between 2000-2007. One boy interrupted treatment and the follow-up of two boys was carried out at another hospital. The data of 18 patients are reported. Results. The mean age of patients at the beginning of treatment was 14 years (11-17) and the average thoracic kyphosis was 71° (50-94). On extension radiographs, the kyphosis decreased to 43°(16-66) with a mean correction of 38%. The average time of brace treatment was 2,5 (1-7) years. The final follow- up visit was at the age of 19 (15-21) years. At the final follow-up, the mean thoracic kyphosis was 59° (30-78). Permanent correction of thoracic kyphosis was achieved in 15 patients (83%) with a mean correction of 15 degrees. In two patients no correction was achieved and in one patient the kyphosis increased 9°. No patient required operative treatment. Discussion and conclusion. The efficiency of brace treatment is difficult to prove because natural history of Scheuermann's kyphosis is not fully known. Our material is too small for any final conclusions. However, treatment of the growing spine with modified low profile brace seem to decrease progression of kyphosis in most cases and operative treatment may be avoided

Purpose: Analysis of the sagittal balance of the spine is a fundamental step in understanding spinal disease and proposing appropriate treatment. The objectives of this prospective study were to establish the physiological values of pelvic and spinal parameters of sagittal spinal balance and to study their interrelations. Material and methods: Two hundred fifty lateral views of the spine taken in the standing position and including the head, the spine and the pelvis were studied. The following variables were noted: lumbar lordosis, thoracic kyphosis, sagittal tilt at 9, sacral slope, pelvic incidence, pelvic version, intervertebral angle, and the vertebral wedge angle from T9 to S1. These measures were taken after digitalising the x-rays. Two types of analysis were performed. A descriptive univariate analysis was used to characterise angular parameters and a multivariate analysis (correlation, principal component analysis) was used to compare interrelations between the variables and determine how economic balance is achieved. Results and discussion: Mean angular values were: maximal lumbar lordosis 61±12.7°, maximal thoracic kyphosis 41.4±9.2°, sacral slope 42±8.5°, pelvic version 13±6°, pelvic incidence 55±11.2°, sagittal tilt at T9 10.5±3.1°. There was a strong correlation between sacral slope and pelvic incidence (r=0.8), lumbar lordosis and sacral slope (r=0.86), pelvic version and pelvic incidence (r=0.66), lumbar lordosis pelvic incidence pelvic version and thoracic kyphosis (r=0.9), and finally between pelvic incidence and sagittal tilt at T9, sacral slope, pelvic version, lumbar lordosis, and thoracic kyphosis (r=0.98). Multivariate analysis demonstrated three independent parameters influencing sagittal tilt at T9, reflecting the lateral balance of the spine. The first was a linear combination of the pelvic incidence, lumbar lordosis and sacral slope. The second was pelvic version and the third thoracic kyphosis. Conclusion: This work provides an aid for analysis and comprehension of anteroposterior imbalance observed in spinal disease and also to calculate with the linear regression equations describing the corrections to be obtained with treatment

Purpose. compare the radiological results in sagittal balance correction obtained with pedicle subtraction osteotomy (PSO) versus anterior-posterior osteotomy (APO) by double approach in adults. Material and Methods. between January of 2001 and July of 2009, fifty-eight vertebral osteotomies were carried out in fifty-six patients: 9 Smith-Petersen osteotomy (SPO), one vertebral resection osteotomy (VRO), 30 anterior-posterior osteotomies (APO) and 18 pedicle subtraction osteotomies (PSO), being the lasts two groups the sample studied (48 osteotomies). The mean age of the patients was 56.3 years (17–72). Initial diagnose was: 28 posttraumathic kyphosis, 7 postsurgical kyphosis, 7 adult degenerative disease, 4 ankylosing spondylitis and 2 congenital kyphoscoliosis. We evaluated the preoperative standing radiographs, the postoperative and at final follow-up by digital measurements with iPACS system viewer (© Real Time Image, USA, 2001). The mean follow-up was 54 months (6–98), and complications were analized. Results. The group APO had a mean preoperative thoracic kyphosis of 67 °, a mean lumbar lordosis of −42° and a mean sagital balance of 8.6°. The group PSO had a mean preoperative thoracic kyphosis of 41°, a mean lumbar lordosis of −22° and a mean sagital balance of 12.3°. The mean correction in the APO group was 29° in its thoracic kyphosis, 8° of lumbar lordosis and 6.5° in its sagital balance. The mean correction in the PSO group was 12° of the thoracic kyphosis, 25 in the lumbar lordosis and 8.4 cm in the sagital balance. The local correction obtained at the osteotomy level was 28° in the APO group and 25.3° in the PSO group. There were no statistically significant differences in the percentage of correction between both groups (p>0.05). In terms of complications, PSO group had lower complication rate (26.6%) comparing to ODV group (44.5%). Conclusions. APO and PSO are useful techniques to correct the global sagital balance in patients with a disturbance of the sagittal profile. The correction obtained with the PSO is similar to obtained with the APO. Patients undergoing an OSP had a lower complication rate than patients undergoing APO

Purpose: To determine the results and safety of patients undergoing|spinal cord level (SCL) pedicle subtraction osteotomy (PSO) for thetreatment of thoracic kyphosis. Methods: Retrospective chart and radiographic review of 25 patients with severe thoracic kyphosis. Results: The underlying diagnoses were: tumour (8), Scheuermann’s Kyphosis (4), degenerative/osteoporosis (3), fracture (3), inflammatory|(2), neurofibromatosis (2), congenital kyphosis (1), tuberculosis (1), and infected tumour (1). The osteotomy was combined with a lumbar PSO in|five patients. Three patients were treated with double thoracic|osteotomies. Two PSOs were extended transdiscally to debride the|infected disc. The mean focal PSO correction was 33.6° (range 9°–73°). The overall thoracic kyphosis measured from T5 to T12 improved from a|mean of 58.3° preoperatively to 37.1° postoperatively. Estimated blood|loss ranged from 400cc to 12500cc. All patients presenting with spinal|cord dysfunction neurologically improved postoperatively. There were 2 major neurological complications. One patient developed postoperative | progressive paraplegia following a prolonged period of intra- and | postoperative severe hypotension and coagulopathy. The other developed a| pseudoarthrosis five months postoperatively and suffered an incomplete|spinal cord injury during the subsequent revision. Other complications included: T3 radicular pain (1) -resolved; dural tears (2); respiratory failure -prolonged ICU admission(1); fractures proximal to the thoracic (2) and distal to lumbar (1) instrumentation; incomplete corrections of the sagittal alignment despite double osteotomies (2); wound breakdown associated with preoperative radiation (1).|. Conclusions: SCL-PSO is a feasible option for severe thoracic kyphosis. This procedure eliminates the need for anterior surgery; however, it does not reduce the potential for significant morbidity

To present the results of surgical correction in patients with double or triple thoracic/lumbar AIS (Lenke types 2,3,4) with the use of a novel convex/convex unilateral segmental screw correction technique in a single surgeon's prospective series. We reviewed the medical records and spinal radiographs of 92 consecutive patients (72 female-20 male). We measured scoliosis, thoracic kyphosis, lumbar lordosis, scoliosis flexibility and correction index, coronal and sagittal balance before and after surgery, as well as at minimum 2-year follow-up. SRS-22 data was available preoperatively, 6-month, 12-month and 2-year postoperatively for all patients. Surgical technique. All patients underwent posterior spinal fusion using pedicle screw constructs. Unilateral screws were placed across the convexity of each individual thoracic or lumbar curve to allow for segmental correction. ‘Corrective rod’ was the one attached to the convexity of each curve with the correction performed across the main thoracic scoliosis always before the lumbar. Maximum correction of main thoracic curves was always performed, whereas the lumbar scoliosis was corrected to the degree required to achieve a balanced effect across the thoracic and lumbar segments and adequate global coronal spinal balance. Concave screws were not placed across any deformity levels. Bilateral screws across 2 levels caudally and 1–2 levels cephalad provided proximal/distal stability of the construct. Mean age at surgery was 14.9 years with mean Risser grade 2.8. The distribution of scoliosis was: Lenke type 2–26 patients; type 3–43 patients; type 4–23 patients. Mean preoperative Cobb angle for upper thoracic curves was 45°. This was corrected by 62% to mean 17° (p<0.001). Mean preoperative Cobb angle for main thoracic curves was 70°. This was corrected by 69% to mean 22° (p<0.001). Mean preoperative Cobb angle for lumbar curves was 56°. This was corrected by 68% to mean 18° (p<0.001). No patient lost >2° correction at follow-up. Mean preoperative thoracic kyphosis was 34° and lumbar lordosis 46°. Mean postoperative thoracic kyphosis was 45° (p<0.001) and lumbar lordosis 46.5° (p=0.69). Mean preoperative coronal imbalance was 1.2 cm. This corrected to mean 0.02 cm at follow-up (p<0.001). Mean preoperative sagittal imbalance was −2 cm. This corrected to mean −0.1 cm at follow-up (p<0.001). Mean theatre time was 187 minutes, hospital stay 6.8 days and intraoperative blood loss 0.29 blood volumes (1100 ml). Intraoperative spinal cord monitoring was performed recording cortical and cervical SSEPs and transcranial upper/lower limb MEPs and there were no problems. None of the patients developed neurological complications, infection or detected non-union and none required revision surgery to address residual or recurrent deformity. Mean preoperative SRS-22 score was 3.6; this improved to 4.6 at follow-up (p<0.001). All individual parameters also demonstrated significant improvement (p<0.001) with mean satisfaction rate at 2-year follow-up 4.9. The convex-convex unilateral pedicle screw technique can reduce the risk of neurological injury during major deformity surgery as it does not require placement of screws across the deformed apical concave pedicles which are in close proximity to the spinal cord. Despite the use of a lesser number of pedicle fixation points compared to the bilateral segmental screw techniques, in our series it has achieved satisfactory scoliosis correction and restoration of global coronal and sagittal balance with improved thoracic kyphosis and preserved lumbar lordosis. These results have been associated with excellent patient satisfaction and functional outcomes as demonstrated through the SRS-22 scores

Purpose of the study. To compare the effectiveness of unilateral and bilateral pedicle screw techniques in correcting adolescent idiopathic scoliosis. Summary of Background Data. Pedicle screw constructs have been extensively used in the treatment of adolescent patients with idiopathic scoliosis. It has been suggested that greater implant density may achieve better deformity correction. However, this can increase the neurological risk related to pedicle screw placement, prolong surgical time and blood loss and result in higher instrumentation cost. Methods. We reviewed the medical notes and radiographs of 139 consecutive adolescent patients with idiopathic scoliosis (128 female-11 male, prospectively collected single surgeon's series). We measured the scoliosis, thoracic kyphosis (T5-T12), and lumbar lordosis (L1-L5) before and after surgery, as well as at minimum 2-year follow-up. SRS 22 data was available for all patients. Results. All patients underwent posterior spinal arthrodesis using pedicle screw constructs. Mean age at surgery was 14.5 years. We had 2 separate groups: in Group 1 (43 patients) correction was performed over 2 rods using bilateral segmental pedicle screws; in Group 2 (96 patients) correction was performed over 1 rod using unilateral segmental pedicle screws with the 2. nd. rod providing stability of the construct through 2-level screw fixation both proximal and distal. Group 1. Mean Cobb angle before surgery for upper thoracic curves was 37°. This was corrected by 71% to mean 11° (p<0.001). Mean Cobb angle before surgery for main thoracic curves was 65°. This was corrected by 71% to mean 20° (p<0.001). Mean Cobb angle before surgery for thoracolumbar/lumbar curves was 60°. This was corrected by 74% to mean 16° (p<0.001). No patient lost >2° correction at follow-up. Mean preoperative thoracic kyphosis was 24° and lumbar lordosis 52°. Mean postoperative thoracic kyphosis was 21° and lumbar lordosis 50° (p>0.05). Mean theatre time was 5.5 hours, hospital stay 8.2 days and intraoperative blood loss 0.6 blood volumes. Complications: 1 transient IOM loss/no neurological deficit; 1 deep wound infection leading to non-union and requiring revision surgery; 1 rod trimming due to prominent upper end. Mean preoperative SRS 22 score was 3.9; this improved to 4.5 at follow-up (p<0.001). Pain and self-image demonstrated significant improvement (p=0.001, p<0.001 respectively) with mean satisfaction rate 4.9. Group 2. Mean Cobb angle before surgery for upper thoracic curves was 42°. This was corrected by 52% to mean 20° (p<0.001). Mean Cobb angle before surgery for main thoracic curves was 62°. This was corrected by 70% to mean 19° (p<0.001). Mean Cobb angle before surgery for thoracolumbar/lumbar curves was 57°. This was corrected by 72% to mean 16° (p<0.001). No patient lost >2° correction at follow-up. Preoperative scoliosis size for all types of curves correlated with increased surgical time (r=0.6, 0.4). Mean preoperative thoracic kyphosis was 28° and lumbar lordosis 46°. Mean postoperative thoracic kyphosis was 25° and lumbar lordosis 45° (p>0.05). Mean theatre time was 4.2 hours, hospital stay 8.4 days and intraoperative blood loss 0.4 blood volumes. Complications: 1 deep and 1 superficial wound infections treated with debridement; 1 transient brachial plexus neurapraxia; 1 SMA syndrome. Mean preoperative SRS 22 score was 3.7; this improved to 4.5 at follow-up (p<0.001). Pain, function, self-image and mental health demonstrated significant improvement (p<0.001 for all parameters) with mean satisfaction rate 4.8. Comparison between groups showed no significant difference in regard to age at surgery, preoperative and postoperative scoliosis angle for main thoracic and thoracolumbar/lumbar curves, as well as SRS scores and length of hospital stay. Better correction of upper thoracic curves was achieved in Group 1 (p<0.05), but upper thoracic curves in Group 2 were statistically more severe before surgery (p<0.05). Increased surgical time and blood loss was recorded in Group 1 (p<0.05, p=0.05 respectively). The implant cost was reduced by mean 35% in Group 2 due to lesser number of pedicle screws. Conclusion. Unilateral and bilateral pedicle screw instrumentation has achieved excellent deformity correction in adolescent patients with idiopathic scoliosis, which was maintained at follow-up. This has been associated with high patient satisfaction and low complication rates. The unilateral technique using segmental pedicle screw correction has reduced surgical time, intraoperative blood loss and implant cost without compromising surgical outcome for the most common thoracic and thoracolumbar/lumbar curves. The bilateral technique achieved better correction of upper thoracic scoliosis

Background. The factors influencing normal spine curvature in midlife are unknown. We performed an MR and plain radiograph study on well characterised, unselected twin volunteers from the TwinsUK register (. www.twinsuk.ac.uk. ) to determine the relative contributions of genetic and environmental factors to spine curve. Methods. T2 weighted MR scans and long spine standing radiographs were obtained at the same morning visit on twin pairs. Midline sagittal MR images were coded for 4 degenerative features. SpineviewTM software was applied plain films and calculated the angles of curvature. A classical twin study was performed. Multivariate regression analysis was used to determine the association between spine curves, LDD and confounders (age, body mass index). Results. Data were available on 110 monozygotic (MZ) and 136 dizygotic (DZ) female twins. Mean age was 64.3 years (range 40.1–79.3); age was associated with increasing lumbar lordosis (p=0.02). The AE model (comprising additive genetic and unique environmental factors) was the most suitable model for both lumbar lordosis and thoracic kyphosis (as determined by Akaike information criterion). Heritability estimates = 59% (42–71%) for lumbar lordosis; and 61% (46–74%) for thoracic kyphosis. After adjusting for age and BMI, lumbar lordosis was significantly associated with a number of features of LDD (p<0.001) including disc signal intensity and osteophytes. Conclusion. The twins are known to be representative of women in the general population. Lumbar lordosis and thoracic kyphosis of the spine have considerable heritable component in females suggesting that a search for individual gene variants would be a reasonable next step. This abstract was presented at 14th Congress of the International Society for Twin Studies. Conflicts of interest: No conflicts of interest. Sources of funding: No funding obtained

Introduction:. Scheuermann's kyphosis is a fixed round back deformity characterised by wedged vertebrae seen on radiograph. It is known patients presented with a negative sagittal balance before operation. Few studies investigated the outcome after operation, especially the change in the lumbar hyperlordosis. Aim:. To investigate the change in sagittal profile after correction surgery. Method:. This is a retrospective review of cases from 2001 to 2012. Our centre uses a posterior, four rod cantilever reduction technique for all Scheuermann's Kyphosis correction. 36 cases are identified. They include 24 males and 12 females with an average age of 20 and follow up of 27 months. First 8 cases used the stainless steel hybrid implants. The remaining 28 had titanium all pedicle screw system. All had intra-operative spinal cord monitoring. Results:. The target of thoracic kyphosis correction is around the accepted upper end of normal limit (40°). The average thoracic kyphosis Cobb angle was 78.5°. The immediate post-op angle was 43.2° and at final follow up, 43.6°. The average lumbar lordosis changed from 65.7° pre-op to 48.8° post-op, which is now bigger than the thoracic kyphosis. The result is the transfer of average sagittal balance (C7 plumb line) from −2.2 cm to −3.5 cm, which remains posterior to the posterior corner of S1 after the surgery. Discussion:. Surgery can improve the roundback deformity but not the overall sagittal profile. We have no explanation to this phenomenon. This could imply the pathology of Scheuermann's Kyphosis involves the whole spine, not just the wedging thoracic segment. Conflict Of Interest Statement: No conflict of interest

The K2M MESA Rail is a new implant with a unique beam-like design which provides increased rigidity compared with a standard circular rod of equivalent diameter potentially allowing greater control and maintenance of correction. The aim of this study was to review our early experience of this implant. We retrospectively reviewed the case notes and radiographs of all consecutive cases of spinal deformity correction in which at least one rail was used. All radiological measurements were made according to the Scoliosis Research Society definitions. Since June 2012 thirty-three cases of spinal deformity correction were performed using the K2M Rail system. One case was excluded as there were no pre-operative radiographs. Median age was 15 years; there were 23 females. There were 26 scoliosis cases of which two had associated Chiari malformation, three were neuromuscular, and the remainder were adolescent idiopathic cases. Six patients had kyphotic deformity secondary to Scheuermann's disease. Mean length of follow-up was 16 months. In the scoliosis cases the mean pre-operative Cobb angle of the major curve was 58.6° with a mean correction of 35.6°. The mean post-operative thoracic kyphosis was 21.1°. The median number of levels included in the correction was 13. Bilateral rails were used in four cases, the remainder had one rail on the concave side and a contralateral rod. No patients required an anterior release or staged surgery. All kyphosis cases had posterior apical corrective osteotomies. The mean pre-operative thoracic kyphosis was 75.5° with a mean correction of 31°. The median number of levels included in the correction was 11. Four patients had bilateral rails. No patients required anterior release. Complications: two patients had prominent hardware. One patient had a malpositioned screw causing nerve root irritation, which was removed. There were three superficial infections, which settled with antibiotics. There were no cases of implant breakage, screw pull-out, or loss of correction. The K2M MESA Rail is a powerful new implant design which helps to achieve and maintain satisfactory correction of complex spinal deformity, and is particularly strong at correcting kyphotic deformity. It also enables restoration of normal thoracic kyphosis, particularly in idiopathic thoracic curves, which tend to be lordosing. This may prevent thoracic flat back and potential long-term sequelae. Early results show that the system is as safe and effective as other posterior deformity correction implants on the market, however, it requires further prospective follow-up to ascertain its outcomes in the long-term

Introduction. Sparing of the spinal growth and scoliotic deformity control in patients with early-onset scoliosis is a challenge in spinal surgery. Loss of the surgical correction, implant breakage, and revision surgeries are the main disadvantages of present treatment methods. The purpose of this study is to investigate whether growing transpedicular instrumentation spares achieved surgical correction during patient's growth. Methods. This is a prospective study of 12 consecutive patients with early-onset scoliosis from one clinical centre. All patients underwent anterior convex growth arrest and posterior transpedicular instrumentation with growing construct. Spinal derotation was used for the correction of the deformity. The diagnoses were infantile idiopathic (n=10) and congenital (n=2) scoliosis (formation failure). Follow-up was 3 years. Mean age at the time of surgery was 9·1 years. Results. Preoperative major Cobb angle was 74·3° (range 52–100°), minor Cobb angle was 32·2° (5–50°), and average preoperative thoracic kyphosis was 27·2° (0–63°). Mean number of the instrumented levels was 12·2. Postoperative major Cobb angle was 22·4° (0–40°), minor Cobb angle was 5·7° (0–23·5°), and postoperative thoracic kyphosis was 26·2° (6–41°). After 3 years of follow-up, primary curve was an average of 22·7° (10–40°), secondary curve was 5·4° (0–25°), and mean thoracic kyphosis was 28° (12–40°). Mean growth of the instrumented spine was 18 mm. We did not observe any gross complications in the patients. Two patients had pleural effusion, and one needed rod exchange 15 months after primary surgery because of insufficient length. Conclusions. The results of this study show that anterior convex growth arrest and polysegmental transpedicular spinal instrumentation with growing construct save spinal growth and anatomical values achieved after surgical correction. Rod derotation for the deformity correction favours spinal growth in skeletally immature patients

Background: To analyse the effects of surgery on sagittal alignment. 1. in patients with severe Scheuermann’s kyphosis. To assess the ability of two surgical techniques to prevent loss of correction in the thoracic kyphosis. To assess factors of patient’s Body Mass Index (BMI) and instrumentation level on the risk of adjacent level kyphosis or pullout. Methods: A retrospective study of 13 consecutive cases of rigid Scheuermann’s kyphosis. Group A: 6 patients with anterior interbody cages. GroupB: 7 patients with interbody autogenous rib graft. All patients were instrumented posteriorly from T2 to L2. Radiographs from initial presentation, pre-operatively, post-operatively and at final follow –up were assessed. The thoracic kyphosis, lumbar lordosis, sagittal balance. 2. and sacral inclination were measured. Results: There were 7 males and 6 females with a mean age of 22 years (range 15 to 38yrs). The mean follow-up was 26 months (range 7 to 53 mths). In Group A: the mean preoperative kyphosis was 87° (range 82° to 92° ) and postoperative kyphosis was 45° (range 38° to 60°). The mean loss of correction was 0.3° (range 0° to2°). In Group B: the mean preoperative kyphosis was 83° (range 70° to 100°) while the postoperative kyphosis was 43° (range 30° to 60°). The mean loss of correction was 1.1° (range 0°to 2°) at final follow-up. The mean lumbar lordosis pre-operatively for all patients was 66° (range 62° to 84°) reducing to 48° (range 34° to 82°) following surgery. The mean sacral inclination pre-operatively was 41° (range 18° to 80°) reducing to 32 °(range 14°to 40°) following surgery. The mean sagittal balance preoperatively was −1.1 cm (range +0.1 to −3.5). It reduced postoperatively to −2.2 cm (range +1.5 to −4 cm) and was −1.6cm (range +0.2 to – 3.5cm) at final follow- up. Three patients with BMI greater than 25 had an increased lumbar lordosis at final follow up, with one case of implant failure and 2 cases with lower junctional kyphosis. No patient had an upper thoracic junctional kyphosis. There was no evidence of neurological compromise. Conclusion: Patients had a mean thoracic kyphosis correction of 41° (49%). This was maintained during follow-up with no significant difference between autograft and cages. Cranially, all patients had instrumentation to T2 and there was no junctional kyphosis. Caudally, three obese patients (BMI > 25) suffered screw pullout (1 patient) or junctional kyphosis (2 patients). Instrumentation to L3 may avoid this complication in this patient group. The lumbar lordosis and sacral inclination reduced immediately postoperatively, with further correction at final follow –up

Introduction and Objectives: This is a retrospective radiographic study of results of surgical correction of thoracolumbar and King I scoliosis using segmental instrumentation. Materials and Methods: This study includes 44 patients (41 female, 3 male) with an average age of 16.8 years (12-40) and 5.9 years average progression. The number of instrumented levels was 5.1 (4–7). Curve magnitude, T1–S1 imbalance, and the angles of the instrumented zone were measured using teleradiographic studies with an anteroposterior view. Thoracic kyphosis and lumbar lordosis were measured in the sagittal plane, and the thoracic and lumbar regions were measured in the instrumented area. Results: On the anteroposterior view, average magnitude of principal preoperative curve, postoperative curve, and final result was 48°, 11.9°, and 14.7°, respectively. A final correction of 69.3% was obtained. T1–S1 imbalance improved from an initial 2.1cm to 1.9cm postoperatively and a final result of 0.5cm. On the lateral view, preoperative, postoperative, and final thoracic kyphosis were 29.5°, 27.8°, and 30.4°, respectively. Average figures for lumbar lordosis were 59.2°, 55.6°, and 61.1°. The instrumented thoracic zone went from 0.8° kyphosis preoperatively to 4.7° final kyphosis, and the lumbar area of instrumentation went from 9.7° preoperative lordosis to a final angle of 10.4°. Discussion and Conclusions: In our experience, correction of thoracolumbar and King I scoliosis using anterior instrumentation has given good results, obtaining an initial 75% correction of the principal curve and an average loss of only 3° on follow-up. In the sagittal plane, there is no loss of kyphosis and lordosis, both of which are within normal physiological ranges. Thoracic kyphosis was increased 3.9° in the instrumented zone, and although instrumented lordosis did not improve, a kyphotic effect was observed

Objective. To compare the radiological and clinical outcomes following three different techniques used in the correction of Scheuermann's kyphosis. Materials and Methods. Twenty three patients with comparable preoperative radiographic and physical variables (age, gender, height, weight, body mass index) underwent correction of thoracic kyphotic deformity using three different surgical methods. Group A (n=8) had combined anterior and posterior fusion with instrumentation using morselised rib graft. Group B (n=7) had combined anterior and posterior fusion with instrumentation using titanium interbody cages. Group C (n=8) had posterior segmental pedicle screw fixation only. All groups had posterior apical multi-level chevron osteotomy and posterior instrumentation extending from T2 to L2/3. Preoperative and postoperative curve morphometry studied on plain radiographs included Cobb angle, sagittal vertical axis (SVA), sacral inclination (SI) and lumbar lordosis (LL). Preoperative and postoperative questionnaires including ODI, VAS and SRS-22 were also analysed. Results. The average follow-up was 70 months for group A, 66 months for group B and 35 months for group C. For the whole cohort, the preoperative median cobb angle for thoracic Kyphosis was 88.4°, SVA +3.5 centimeters (cms), lumbar lordosis was 66 °, and the median sacral inclination angle was 40°. The average immediate postoperative cobb angle for thoracic kyphosis was 42°, SVA -1.5 cms, lumbar lordosis 45 ° and sacral inclination angle was 30°. At follow-up, the average cobb angle for thoracic kyphosis was 42.0°, SVA +1 cm, lumbar lordosis 42.0 ° and sacral inclination angle was 22.0 °. There was a significant difference between preoperative and postoperative measurements in all three groups, indicating that good correction and satisfaction was achieved. Three patients had distal junctional Kyphosis in early cases. There was no significant difference obtained in the final cobb angle between group A, group B and group C. All three groups retained the postoperative correction with respect to thoracic kyphosis, and changes in ODI and SRS-22 scores were similar in three groups. Conclusion. In all groups the SVA became negative following correction and at long-term follow-up it was observed to return towards normal physiological limits. The compensatory lumbar curve reduces and this was associated with a decrease in sacral inclination. This method of compensation, without causing junctional kyphosis, has not previously been reported. We were unable to demonstrate a significant difference between the three groups with regards to the clinical outcome, the degree of initial correction, loss of correction and complications. Therefore, in conclusion, we believe a single stage posterior correction and segmental instrumentation not only provides the same clinical and radiological outcomes, but also reduces blood loss, operative time and hospital stay. Ethics approval: None. Interest Statement: None

This study is a retrospective monocentric analysis of changes in spinopelvic sagittal alignment after in situ fusion of L5-S1 spondylolisthesis. In situ fusion is a safety procedure with good functionnal outcome, but the consequences on the spinopelvic sagittal balance remains unclear. The aim is to evaluate the adaptative changes in the sagittal balance after such treatment. This is an analysis of 22 patients (mean age 13,5 years) with an average follow-up of 5,2 years (range 1–11 years). This study includes 6 grade II spondylolisthesis, 7 grade III and 9 grade IV. 13 patients were operated with a non instrumented posterolateral arthrodesis and 9 with a circumferential in situ fusion. Among the 13 grade II and III spondylolisthesis, 12 had a posterolateral arthrodesis and only 1 had a circumferential fusion. As for the grade IV spondylolisthesis 8 out of 9 had a circumferential arthrodesis and only 1 had a posterolateral fusion. Before and after surgery, all patients had lateral standing radiographs of the spine and pelvis. Different parameters were evaluated before surgery: pelvic incidence, sacral slope, pelvic tilt, lumbar lordosis, thoracic kyphosis, T9 sagittal tilt, L5 incidence, L5 slope and L5 tilt. After surgery, the pelvic parameters were not evaluated because of the difficulty to visualise the upper part of S1 after arthrodesis. The discs were evaluated by MRI. The functionnal outcome was evaluated with the Oswestry score. A global evaluation including all the patients doesn’t show any influence of the surgery on the sagittal alignment. But when evaluating the datas after classifying the patients in function of the severity of the spondylolisthesis, some differences raise. On one side, the patients with grade II and III spondylolisthesis keep a normal T9 sagittal tilt while slightly increasing lumbar lordosis and thoracic kyphosis. On the other side, the patients with grade IV spondylolisthesis operated with a circumferential in situ fusion worsen the T9 sagittal tilt, increase the L5 incidence, decrease their lombar lordosis (L4/L5 discal kyphosis) and thoracic kyphosis. To conclude, we can say that patients with grade II and III spondylolisthesis have good functionnal outcome and keep a balanced spine. Patients with grade IV have a good clinical outcome as well but keep worsening their sagittal balance despite the circumferential in situ fusion. An unbalanced sagittal alignment might theorically compromise the long term clinical results, but the radiological outcome doesn’t seem to be linked to the functionnal outcome. A long term follow-up has to be done in order to evaluate the outcome of these unbalanced spines and compare it to the functionnal and radiological results obtained with reduced high grade spondylolisthesis

The goal of treatment in scoliosis is not only curve correction. Restoration of normal sagittal alignment is also very important. Methods describing sagittal balance are various, they include measurement of thoracic kyphosis and lumbar lordosis, alignment of thoracolumbar junction and distance between plumb line from C7 and sacral bone. Goals of work:. Evaluation the sagittal plane alignment after surgery in idiopathic scoliosis, type 5 and 6 according to Lenke classification;. Establishing risk factors of bad end result. Material consists of 52 patients. The mean age at the time of surgery was 16 years with the follow up time of 4 years. There were 29 patients in first group, with Lenke type 5 and 23 patients in the second group, with type 6. The Cobb angle of structural curves was in Lenke 5 group 52.5o ± 5.9 and in Lenke 6 group − 54.4o ± 8,4 in thoracic spine and 66.3o ± 11.9 in lumbar spine. Preoperative thoracic kyphosis was 20.9o ± 6.9 and 29.3o ± 15.5. Lumbar lordosis was 42.5o ± 11.4 and 35.9o ± 11.4. Thoracolumbar junction was almost straight in first group; Th12-L2 angle was 0o ± 6.7 and slight kyphotic in second group: 4o ± 8.1. All the patients underwent posterior fusion with derotational instrumentation. Radiological assessment was performed using postero-anterior and lateral radiograms. Own scale of treatment result evaluation was introduced. Results: During control examination the thoracic kyphosis was 30.1o ± 7.8 and 27.8o ± 9.4 and lumbar lordosis was 40.3o ± 12.3 and 35.7o ± 9.9. During follow-up, the mean thoracolumbar junction angle was −4.4o ± 9.6 and −7.9o ± 9.9. Proper alignment of thoracolumbar junction was observed in 24 patients (82.8%) from first group and 21 patients (91%) from the second. Good results in sagittal plane were noted in 22 cases (76%) from Lenke 5 group and 21 cases (91%) from Lenke 6 group. The presence of pedicle srews in lumbar spine was bound with significantly better end result. Smaller lordosis, greater probability of bad result. Kyphotic thoracolumbar junction before surgery was connected with greater risk of bad result. The level of lower end of fusion was significantly important in pre-dicticting end result. Conclusions:. Own method of describing result in sagittal plane allows better assessment of sagittal balance;. There are several factors influencing end result in sagittal plane in scoliosis surgery;. The best indicator of bad sagittal result is improper alignment of thoracolumbar junction