Aims. The development of lumbar lordosis has been traditionally examined using angular measurements of the spine to reflect its shape. While studies agree regarding the increase in the angles during growth, the growth rate is understudied, and sexual dimorphism is debated. In this study, we used a novel method to estimate the shape of the lumbar curve (LC) using the landmark-based geometric morphometric method to explore changes in LC during growth, examine the effect of size and sex on LC shape, and examine the associations between angular measurements and shape. Methods. The study population included 258 children aged between 0 and 20 years (divided into five age groups) who underwent a CT scan between the years 2009 and 2019. The landmark-based geometric morphometric method was used to capture the LC shape in a sagittal view. Additionally, the lordosis was measured via Cobb and sacral slope angles. Multivariate and univariate statistical analyses were carried out to examine differences in shape between males and females and between the age groups. Results. The overall shape of the LC overlapped between males and females in most age groups, except for the nine- to 12-year age group. However, size did not affect LC shape. LC shape changed significantly during growth from straight to curved, reaching its mature shape earlier in females. This corresponded with the results obtained by the lordosis and sacral slope angles. A significant positive correlation was found between the LC shape and angles, although the angles demonstrated poor distinction between age groups, as opposed to the LC shape. Conclusion. New insights into LC shape development were achieved using the geometric morphometric method. The LC shape was sex-independent in most age groups. However, the LC reached its mature shape earlier in females than males. The method and data of this study are beneficial for future studies examining aetiological factors for spinal pathologies and maldevelopment. Cite this article: Bone Joint Res 2025;14(1):58–68

Introduction: In this study we focus on idiopathic scoliosis with a primary thoracic curve and a secondary lumbar curve. We were interested in how the lumbar curve corrects following selective thoracic fusion and whether one can predict the correction of the lumbar curve. In the literature it is said that the lumbar curve spontaneously corrects to balance the thoracic curve after selective thoracic fusion. Because of these findings we postulate there should be a correlation between the correction of the lumbar and thoracic curve of the scoliosis. Recently we showed in patients treated with Harrington instrumentation with sublaminar wiring (second generation technique) that the correction of the lumbar curve was not a reflection of the thoracic correction. So it is interesting to know whether with the use of third generation instrumentation techniques and more sophisticated classification systems the correlation of the unfused lumbar cure becomes more predictable. Objective: To establish whether in primary thoracic idiopathic scoliosis treated with selective thoracic fusion using CD instrumentation there is a significant correlation (p< 0.05) between the correction of the thoracic and lumbar curve. And to assess whether, in the in the individual patient, the lumbar modifier (A, B and C) according Lenke, can be used as a correct predictor of outcome results. The higher the correlation coefficient between the relative (%) corrections of the thoracic and lumbar curves, the higher the predictability of the correction of the unfused lumbar curve. Material and methods: We performed a retrospective study on 38 patients with adolescent idiopathic scoliosis treated by selective thoracic fusion (CD instrumentation). There were 29 female and nine male patients. For radiographic evaluation we used the standing antero-posterior and lateral projections of the thoracic and lumbar spine, preoperatively and at least one year postoperative. We assessed the frontal and sagittal Cobb angles. The angles were all measured by the same investigator (second author). Results: Using Pearson correlation analyses we found a significant correlation (p< 0.001) between the relative (%) corrections of thoracic and lumbar curves (table1). The correlation coefficient between the relative correction of the thoracic and lumbar curve decreased with the Lumbar modifier (A, B, C). Conclusion: A significant correlation is present between the relative corrections of the main thoracic curve and the lumbar curve after selective thoracic fusion in idiopathic scoliosis. The recently introduced new classification system seems to be of great predictable value for the spontaneous correction of the lumbar curve. Depending on the curve-type, a different technique for predicting the outcome should be used

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;

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;

Adolescent idiopathic scoliosis is a three-dimensional deformity of the spine, affecting 1–3% of the population. Most cases are treated conservatively. Curves exceeding 45° in the thoracic spine and 40° in the lumbar spine may require correction and fusion surgery, to limit the progression of the curve and prevent restrictive pulmonary insufficiency (curves above 70°). When fusion is required, it may be performed either by posterior or anterior approaches. Posterior is useful for thoracic (Lenke I) curves, notably to correct the thoracic hypokyphosis frequently observed in AIS. Anterior approaches by thoraco-lombotomies allow an effective correction of thoraco-lumbar and lumbar curves (Lenke V and VI), with fewer levels fused than with posterior approaches. However, the approach requires diaphragm splitting and one may be concerned about the long-term pulmonary consequences. The literature provides conflicting insight regarding the consequences of the approach in anterior scoliosis correction, the interpretation of the results being difficult knowing that the correction of the scoliosis itself may improve pulmonary function. This is a retrospective observational study done at a Tertiary Institution. The HRQOL scores have been collected as a prospective cohort. Clinical and radiographic data was collected from patients charts and analysed by two senior surgeons. A cohort of 64 patients were operated in the given time period. 50 patients met the inclusion criteria. No major complications were reported. The Union rate was 100% and no post operative complications were noted. Pre and post SRS scores improved in all patients. The Anterior approach for Lenke V AIS gives great surgical exposure and allows for excellent correction of Cobb angle with minimal risk to the patient

Adolescent idiopathic scoliosis (AIS) is a complex three-dimensional deformity of the spine characterized by a Cobb angle of at least 10 degrees. The goal of surgery is to not only prevent progression but restore sagittal and coronal balance, protecting cardiopulmonary function and improving cosmesis. We reviewed the impact of deformity correction surgery in terms of radiology and patient reported outcome(PROMs). The senior authors prospectively maintained database from 2003 –2022 was retrospectively analysed in terms of pre- and post-operative patient reported outcome measures (SRS 22) as well as radiological parameters. 44 patients with AIS were identified with pre and post op PROMS. The average age at surgery was 15yrs with 84% female. 38% had a Lenke 1 curve and 3 patients had Lenke 6 curves. 73% had posterior surgery. There was a total improvement in SRS 22 scores by 7.8%. Patients reported significant satisfaction with treatment 4.8/5 and improvement in self-image with a change of 0.4 (p<0.001). However, no difference in function, pain and mental health were recorded. Overall, proximal thoracic (PT) curves improved from 24 degrees to 11 degrees (p<0.001), Main thoracic (MT) curve 55 degrees to 19 degrees and Thoracolumbar/Lumbar curves (TL/L) 45 degreesto 11 degrees. Pre-operative flexibility and post-operative correction were 0.40 and 0.41 respectively for PT curve. MT was 0.32 and 0.67. That for TL/L was 0.57 and 0.71 respectively. Surgery yields significant main curve correction correlating with high patient reported satisfaction rate. Although total SRS 22 score yielded 7.8% improvement, sub-analysis of self-image showed the most significant improvement

Introduction. Adolescent Idiopathic Scoliosis (AIS) is a three-dimensional deformity of the spine with unclear etiology. Due to the asymmetry of lateral curves, there are differences in the muscle activation between the convex and concave sides. This study utilized a comprehensive thoracic spine and ribcage musculoskeletal model to improve the biomechanical understanding of the development of AIS deformity and approach an explanation of the condition. Methods. In this study, we implemented a motion capture model using a generic rigid-body thoracic spine and ribcage model, which is kinematically determinate and controlled by spine posture obtained, for instance, from radiographs. This model is publicly accessible via a GitHub repository. We simulated gait and standing models of two AIS (averaging 15 years old, both with left lumbar curve and right thoracic curve averaging 25 degrees) and one control subject. The marker set included extra markers on the sternum and the thoracic and lumbar spine. The study was approved by the regional Research Ethics Committee (Journal number: H17034237). Results. We investigated the difference between the muscle activation on the right and left sides including erector spinae (ES), psoas major (PS), and multifidus (MF). Results of the AIS simulations indicated that, on average throughout the gait cycle, the right ES, left PS and left MF had 46%, 44%, and 23% higher activities compared to the other side, respectively. In standing, the ratios were 28%, 40%, and 19%, respectively. However, for the control subject, the differences were under 7%, except ES throughout the gait, which was 17%. Conclusion. The musculoskeletal model revealed distinct differences in force patterns of the right and left sides of the spine, indicating an instability phenomenon, where larger curves lead to higher muscle activations for stabilization. Acknowledgement. The project is funded by the European Union's Horizon 2020 program through Marie Skłodowska-Curie grant No. [764644]

Background: Lenke 1 curves can be treated by a selective thoracic fusion. The lumbar curve, if flexible, can spontaneously correct itself in terms of the Cobb angle and the apical vertebral translation. De-rotation of the thoracic spine with current instrumentation systems has been reported. However, it is unclear what effect this would have on the un-instrumented lumbar curve. Objective: We report on the changes in the apical rotation (AVR) of the un-instrumented lumbar curve following selective thoracic fusion in Lenke 1B and 1C curves. Methods and patients: 32 patients with idiopathic scoliosis underwent a selective thoracic fusion for a Lenke 1B or 1C curves. We assessed the apical vertebral rotation of the lumbar curve before and after the selective thoracic fusion. This was measured by the Pedriolle method on the pre-, and post-operative erect radiographs. Cobb angle of the thoracic and lumbar curves before and after the fusion were also measured. Results: The apical lumbar rotation changed form a mean of 10.7 deg (pre-op) to 7.33 deg (post-op), with a correction index of 19.8 %. The Cobb angle of the instrumented thoracic curve changed from a mean of 54.4 deg (pre-op) to a mean 24.9 deg (postop), the mean correction index was 52.9 %. The mean Cobb angle of the un-instrumented lumbar curve changed from 29.36 deg (pre-op) to 17.76 deg (post-op), with a correction index of 38.8 %. Conclusion: Selective thoracic fusion of Lenke 1B and 1C leads to an improvement of the rotation un-instrumented lumbar curve

In order to overcome high intra-observer and inter-observer reliability, there is a new classification system for Adolescent Idiopathic Scoliosis (AIS). The type C (King II) of this system describes pronounced lumbar curves in which the center sacral vertical line (CSVL) lies outside the lumbar apical vertebra on the concavity of the curve. It has been proposed that selective anterior thoracic fusion (ATF) is not possible in these cases because of insufficient spontaneous correction of the lumbar curve or postoperative lumbar progression. This retrospective study analyses the results of a group of patients who received selective ATF for type C curves. The purpose of the study was to analyze the ability of the new classification system to predict the outcome of anterior thoracic fusion in the combined AIS type Lenke C, and to define predictive parameters revealed in the study. From 1989 to 1994, 407 patients underwent anterior fusion for scoliotic deformities of different etiologies. There were 174 patients with anterior thoracic fusion. Twenty-one patients (< 19 years old) had combined AIS with a Risser sign < 5 with the criteria of a Lenke type C curve. Fourteen patients had a minimum follow-up of two years. The parameter analysis included coronal and sagittal corrections. Horizontalisation of lumbar and thoracic endvertbrae and correction of both curves were measured on pre-op bending and Cotrel traction films. Fourteen female patients with a mean age of 15.4 years were followed for an average time period of 3.3 years. Mean correction of the lumbar curve and the thoracic curve was 46.0% (±18.5) and 54.7% (±16.4) respectively. Patients with preoperative horizontalisation on Cotrel traction films of the lumbar endvertebra of less than 6° had an average correction of the lumbar curve of 60.1% (±8.1) and an average loss of correction of 3.6% (±14.6); those with more than 5° had 27.2% (±9.7) and 19.4%(±11.5) respectively. Horizontalisation of the thoracic endvertebra of less than 10° on preoperative Cotrel traction films had an average correction of the lumbar curve of 62.7% (±8.7) and −2.8% (±10.4) loss of correction; those with more than 9° had 44.6%(±13) and 12.8%(±13.6) respectively. Preoperative correction of more than 50% of the thoracic curve on Cotrel traction films had an average correction of the lumbar curve of 53.1% (±18.3); loss of lumbar correction was −1.9% (±8.9); less than 50% had 38.9% (±15.7) and 22 % (±10.7) respectively. Patients with combined AIS and pronounced lumbar curves (type C) can be treated with selective anterior thoracic fusion. Horizontalisation of the thoracic and lumbar endvertebrae and correction of the thoracic curve on preoperative Cotrel traction films have an important predictive value for the unfused lumbar curve and are superior to bending films in this context

Introduction: Veldhuizen (2002) developed a new flexible Scoliosis-Brace for effective curve correction in Idiopathic Scoliosis. This new Brace is characterised by a improved cosmetic appearance and wearing comfort compared to conventional ortheses (Cheneau, Boston). We investigated the effectiveness of the TriaC™-Brace regarding the primary curve correction in Idiopathic Scoliosis (IS). Materials and Method: Following the guidelines given by Veldhuizen (2002) we have treated 20 patients (15 girls, 5 boys, average age: 12,43) with diagnosis of IS (King I:6, King II:4, King III:8, King IV:1, lumbar:1) with the TriaC™-Brace from 2002–2004. At the beginning of the therapy with the new orthesis the Risser sign was 2,68 at an average. The daily wearing time was instructed with 22–23 hours. Lumbar curves showed an average cobb angle of 26,1 degrees (standard deviation=8,6) and thoracic curves of 24,4 degrees (standard deviation=6,5). The radiological assessment of primary curve correction (cobb-angle) was performed 6,2 weeks after the beginning of the therapy (anterior posterior radiograph of the spine in standing position with orthesis). Further radiological controls were performed every six months. We evaluated the wearing time, comfort and leisure activity with a valid scoring system (Quality of Life Profile for Spine Deformities). The overall mean wearing time of the Triac™-Brace was 14,7 months. Results: For lumbar curves (n=12) we measured a primary correction of 9,9 degrees (40%; statistically significant, t-test, p=0,01) and for thoracic curves (n=20) of 2,2 degrees (8,4%; not statistically significant, t-test, p=0,42). A insufficient primary curve correction (defined as < 30% of the initial cobb-angle) was observed in 16 thoracic curves (89%) and in 4 lumbar curves (30%). An increasing correction during the therapy as reported by Veldhuizen (2002) could not be observed. There was a curve progression of at least 5 degrees of the cobb-angle in 4 cases. The evaluation by the scoring system (response in 85%) resulted in a high score for cosmetics (4,2/5) and mobility of the back (4,6/5). The wearing time was reported by 90% of the patients with 22–23h. Conclusion: We do not recommend the conservative therapy of thoracic or double curves (King III, King I and II) with the TriaC™-Brace. Larger studies are necessary to investigate the effectiveness of the orthesis in lumbar curves. The improved wearing comfort and cosmetics are a potential advantages of this new orthesis

Aim. To investigate anterior instrumented corrective fusion for thoracolumbar or lumbar scoliosis. Methods. A retrospective review of medical records and radiographs of 38 consecutively managed patients who underwent anterior spine surgery for thoracolumbar curves by a single surgeon between 2001 and 2011. The cohort consisted of 28 female and 10 male patients with idiopathic scoliosis as the commonest aetiology. Data collated and analysed included patient demographics, surgical factors, post-operative management and complications. In addition, radiographic analysis was performed on pre-operative and follow-up x-rays. Results. Thoracolumbar/lumbar curves were corrected from 70 to 27 degrees. The thoracic compensatory curve spontaneously corrected from 34 to 19 degrees. Sagittal imbalance of greater than 4 centimeters was found in 40 percent of patients preoperatively and in 16 percent post operatively (85 percent negative sagittal imbalance, 15 percent positive sagittal imbalance). Rotation according to the Nash-Moe method corrected by 1.13 of a grade. Average operative time was 194 minutes and estimated blood loss was 450 ml. The diaphragm was taken down in 36 of the 38 patients but no post-op ventilation was required. The average high care stay was 1.2 days. Average follow-up was 18 months. Good maintenance of correction was shown at most recent follow-up, with the mean thoracolumbar/lumbar curve measuring 29 degrees, and the mean compensatory thoracic curve measuring 21 degrees. There were no significant neurological or respiratory complications. Conclusion. Anterior corrective fusion for thoracolumbar and lumbar scoliosis is effective in both deformity correction and maintenance thereof. Spontaneous correction of the thoracic curve can be expected and thus limit the fusion to the lumbar curve. Despite the concerns of taking down the diaphragm, there is minimal morbidity. NO DISCLOSURES

Pedicle screw fixation has become the norm for the surgical correction of adolescent idiopathic scoliosis (AIS), with much biomechanical research into different types of rod screw constructs. The senior authors have experience using a monoaxial screw only construct in the correction of AIS since 2003 and the polyaxial screw only construct since 2005. We retrospectively reviewed our experience in the first ten patients with AIS using the polyaxial system and compared this against 18 patients who had been corrected using the monoaxial system. Table I shows our results, expressed as mean and ranges or means ± SD for the main thoracic and lumbar curves. Our early results show that the polyaxial system produces similar correction of both the thoracic and lumbar curves as compared to the monoaxial system in the immediate post-operative period. Though the absolute values for the lumbar curves differ between the two groups the percentage correction shows no statistical difference

Background: In lumbar scoliosis curves of school screening referrals were evaluated (1) for the possible relation of pathomechanisms to standard and non-standard vertebral rotation (NSVR) [. 1. ], and (. 2. ) the relation between apical lumbar axial vertebral rotation and the frontal plane spinal offset angle (FPTA) [. 2. ]. Methods: Consecutive patients referred to hospital during routine school screening using the Scoliometer were examined in 1996–9. None had surgery for their scoliosis. There are 40 subjects with either pelvic tilt scoliosis (11), idiopathic lumbar scoliosis (19), or double curves (10)(girls 31, postmenarcheal 25, boys 9, mean age 15.3 years). One observer (RGB) measured: 1) in AP spinal radiographs Cobb angles (CAs), apical vertebral rotations (Perdriolle AVRs), and trigonometrically sacral alar tilt angle (SATA), and FPTA as the tilt of the T1–S1 line to the vertical; and 2) total leg lengths (tape). Results: Excluding the double curves there are 16 left and 14 right lumbar curves mean CA 11 degrees (range 4–24 degrees), mean AVR 9 degrees (concordant to CA in 18/30, discordant in 7/30), SATA 2.8 degrees (range 0.2–7.7 degrees associated with CA side and severity, p=0.0003), and leg-length inequality 0.7 cm (significantly shorter on left, p< 0.0001 and associated with SATA (p=0.02) but not CA). Neither CA nor AVR in each of the laterality concordant and discordant lumbar or thoracic curves is significantly different. Twenty-six subjects have thoracic curves (16 right) 22 with AVR (mean CA 11 degrees, range 4–17 degrees, AVR 9 degrees, n=22) the CA being associated with each of lumbar CA and SATA (respectively p< 0.0001, p=0.003, n=26). Thoracic curve laterality of CA and AVR is concordant in 12/26 curves and discordant in 10/26 and for concordance/discordance neither is significantly different; thoracic AVR sides with laterality of lumbar curve AVR shown by thoracic AVR (but not CA) being greater in lumbar discordant than in lumbar concordant curves (14 & 7 degrees respectively, p=0.03, n=18 & 7). Both for lumbar curves alone and for lumbar with double curves, AVR by side is significantly associated with FPTA by side (r= −0.568, p=0.001, n=30; r=−0.560, p=0.0002, n=40). Conclusion: (1) It is hypothesized that different pathomechanisms may separately affect the frontal (CA) and transverse (AVR) planes: in discordant curves these mechanisms may neutralize each other and limit curve progression; concordant curves require these biplanar mechanisms to summate and facilitate curve progression. (2) The association of frontal plane spinal tilt angle and lumbar AVR may result from balance mechanisms affecting trunk muscles – mechanisms that may underlie the complication of post-operative frontal plane spinal imbalance or decompensation [. 2. ]

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

Introduction: The aim of this study is to compare the efficacy of the AO Universal Spine System (AO USS) with Harrington-Luque instrumentation for the treatment of King type II idiopathic scoliosis. Methods/Results: A retrospective analysis was performed on two groups of patients with King II adolescent idiopathic scoliosis. The first group consisted of 40 consecutive patients treated with Harrington-Luque instrumentation between 1990 and 1993. The second group consisted of 25 consecutive patients treated with AO USS instrumentation between 1994 and 1996. The groups were well matched with respect to age, sex and curve severity. Inclusion criteria were patients over the age of 12 years with a King II curve pattern and a Cobb angle of greater than 40°. Half of the patients in each group underwent anterior release prior to posterior fusion. All patients were followed up six monthly for 18 months. The thoracic curve, lumbar curve, kyphosis and lordosis were measured using the Cobb method. The mean pre-operative thoracic and lumbar curves were 62° and 43.9° respectively in the Harrington group and 57.5° and 35.9° in the AO USS group. On average 11.4 levels were fused in the Harrington group compared to 10.9 levels in the AO USS group. The mean post-operative correction of the thoracic curve in the AO USS group of 64% was significantly greater than the 51% achieved in the Harrington group (p< 0.005). At 18 months there was a 7% loss of correction in the Harrington group and 9% in the AO USS group. The correction of lumbar curve of 41% in the Harrington group and 46% in the AO USS group at 18 months was not significantly different. In the sagittal plane the AO USS group had significantly better preservation of the lumbar lordosis but there was no difference in kyphosis correction. Blood loss was similar in both groups. Mean operative time of 132 minutes in the AO USS group was shorter than the mean time of 153 minutes in the Harrington group (p< 0.05). Two hooks in the Harrington group became dislodged and two in the AO group. There were no neurological complications in either group. All the patients in both groups achieved a solid fusion. Conclusion: AO USS is a safe and effective instrumentation system for the treatment of King type II adolescent idiopathic scoliosis. Correction of the thoracic curve is superior to that achieved with Harrington-Luque instrumentation and operative time is shorter. AO USS enables better preservation of the lumbar lordosis than Harrington-Luque. There is no difference in blood loss, complication rate and fusion rates between the two techniques. It has become our instrumentation system of choice for this group of patients

The purpose was to analyze preoperative symptoms, curve characteristics, and outcome of surgery in patients operated on for isthmic spondylolisthesis with concomitant scoliosis. Overall, 151(9.1%) of 1667 scoliosis patients had spondylolisthesis treated surgically in 21 (13.9%)(19 females, 2 males; 11 low-, 10 high-grade). Patients' age at admission was 13.5(10-17)y. Preoperatively, 5/21 were pain-free (1 high-grade, 4 low-grade), 7 (2 high-grade) had LBP, 2 (both high-grade) radiating pain, and 7 (5 high-grade) had both. Hamstring tightness was present in 5/10 high-grades. Scoliosis was primary thoracic in 3/11 low-grade and secondary lumbar with oblique rotated take-off of L5 in 8/11 low-grade patients. Of the high-grades, 7/10 had sciatic curves and 3 secondary lumbar. In low-grades, the main indication for surgery was pain in 3/11 and lumbar curve progression or the intent to prevent it in 7/11. The operative technique was uninstrumented posterolateral fusion in 8/11, instrumented L4-S1 fusion with reduction of L4-tilt in 2, and direct repair in 1 patient. High-grades were fused to prevent further slipping regardless of subjective symptoms (uninstrumented anterior 5, combined 2, instrumented reduction 3). Selective thoracic fusion for scoliosis was performed in 3 patients. None of the lumbar curves needed fusion. All sciatic curves resolved. The follow-up time was 10.6(2-21)y. Of the low-grade patients, 5 were pain-free, 4 had moderate pain, and 2 had a severe chronic pain syndrome. One had broken pedicle screws without sequelae. Of the high-grade patients, 4 were pain-free, 6 had moderate pain. One had a pain-free peroneal weakness after slip reduction

Objective: To compare multi surgeon reliability of the classification systems of H. A. King and R.W. Coonrad and to analyse controversial classified curve patterns. Design: Three scoliosis surgeons and one orthopedic fellow were presented the AP radiographs of seventy adolescent idiopathic scoliosis patients. All reviewers assigned a type to each curve according to the classification systems of H. A. King [. 1. ] and R. W. Coonrad [. 2. ]. Subjects: Interobserver agreement and intraobserver reproducibility were tested. Kappa coefficients were used to test reliability. Between the observers, the divergent assignments to curve patterns were analysed in quantitative as well as in qualitative terms. An error analysis was performed. Results: For King’s classification, paired comparisons revealed a mean interobserver kappa coefficient of 0.45, and for Coonrad’s classification system 0.38, respectively. According to Svanholm et al., these values indicate poor reliability in terms of interobserver agreement. Error analyses for both classification systems revealed that the reason for poor reproducibility is disagreement on structural upper thoracic and structural lumbar curves among the observers. Conclusion: Neither King’s nor Coonrad’s method appear to have sufficient interobserver reliabilty. In order to improve reliability we recommend unequivocal description of structural stigmata of upper thoracic and lumbar curves

This study evaluated the sagittal alignment of the spine and pelvis in adolescent idiopathic scoliosis. The pelvic configuration influenced the lumbar lordosis but was not associated with the thoracic kyphosis or with the curve type. The pelvic incidence in adolescent idiopathic scoliosis was higher than that reported in the literature for normal adolescents and was closer to the values of pelvic incidence found in adults. The role of the PI in the pathogenesis of AIS needs to be explored in a comparative study involving AIS patients and normal adolescents. The purpose of this study was to evaluate the sagittal alignment of the spine and pelvis in adolescent idiopathic scoliosis (AIS) based on the curve type. Five sagittal parameters were retrospectively evaluated on lateral radiographs for one hundred and sixty AIS patients: thoracic kyphosis (TK), lumbar lordosis (LL), sacral slope (SS), pelvic tilt (PT) and pelvic incidence (PI). The patients were classified according to their coronal curve type. ANOVA was used to compare the parameters between the curve types and Pearson’s coefficients were used to investigate the relationship between all parameters. The TK was significantly lower for King I, II and III curves as compared to lumbar curves. The LL was higher for lumbar curves, although not significantly. No significant change between the groups was observed for SS, PT and PI. The PI was significantly correlated to LL, SS and PT for all groups. The LL was strongly related to the SS in all cases but not with the TK, except for thoracolumbar curves. The TK mostly depended on the spinal deformity while the LL was mainly influenced by the pelvic configuration. The scoliotic curve type was not associated with a specific pattern of sagittal pelvic configuration. The PI was significantly higher than that reported in the literature for normal adolescents. The role of the PI in the pathogenesis of AIS needs to be explored in a comparative study involving AIS patients and normal adolescents. Further study is needed to evaluate the prognostic value of the PI in AIS. Funding: This research was funded by the Canadian Institute of Health Research. Please contact author for figures and/or diagrams

40% Of the cases of tuberculous (TB) spondylitis involve the lumbar spine. Despite the large forces borne by the lumbar spine and subsequent disability that may result from the TB infection, no studies have reported on the functional outcome. We review the clinical, radiological and patient-orientated functional outcomes using the Oswestry Disability index (ODI) following treatment of lumbar spine TB. The final radiological and ODI assessment was undertaken at follow-up during October 2005 and March 2006 in 37 patients, treated non-operatively for TB of the lumbar spine. The diagnosis was established following a closed needle biopsy. The mean age at follow-up was 35 (range 16 to 76 years). The average duration of symptoms prior to presentation was 9 months (range 2 to 24 months). All patients presented with low backache and night pain but only 42% had constitutional symptoms. 92% had 2-body involvement and L3/4 segment was most commonly involved (35%). The kyphosis measured 13. 0. (range 40. 0. kyphosis to 13. 0. lordosis) and the mean overall lumbar curve was +1. 0. (range 26. 0. kyphosis to 36. 0. lordosis). Ten patients had coronal plane deformity averaging 10. 0. (0. 0. to 22. 0. ). All patients had a minimum of 6 months of anti-TB treatment (6 to 24 months), 76% used spinal brace for a mean of 5 months (2 to 24 months). At the last follow-up the kyphosis was 17. 0. (38. 0. kyphosis to 8. 0. lordosis) with overall average lumbar curve of +3. 0. (18. 0. kyphosis to 36. 0. lordosis). 11 Had mean coronal deformity of 9. 0. (0. 0. to 14. 0. ). 34 Of the patients showed full radiological fusion. The mean ODI was 19% (0 to 55%). We conclude that a favourable functional outcome can be expected with conservative treatment of lumbar spine TB, despite the deformity

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

Introduction. How translation of different parts of spine responds to selective thoracic fusion has not been well investigated. Furthermore, how posterior pedicle-screw-only constructs affect spontaneous lumbar curve correction (SLCC) remains unknown. In a retrospective study, we aimed to investigate the balance change after selective thoracic fusion in Lenke 1C type adolescent idiopathic scoliosis (AIS) treated with posterior pedicle-screw-only constructs. Methods. All AIS cases, surgically treated between 2002 and 2008 in our institute, were reviewed. Inclusion criteria were: patients with Lenke 1C scoliosis treated with posterior pedicle-screw-only constructs; the lowest instrumented vertebra (LIV) ended at L1 level or above; and a minimum 2-year radiographic follow-up. Standing anteroposterior (AP) and lateral digital radiographs from different timepoints (preoperative, immediately postoperative, 3 months postoperative, and final follow-up) were reviewed. In each standing AP radiograph, centre sacral vertical line (CSVL) was drawn first, followed by measurement of the translation (deviation from the CSVL) of some key vertebrae, such as the LIV, LIV+1 (the first vertebra below LIV), LIV+2 (the second vertebra below LIV), LIV+3 (the third vertebra below LIV), lumbar apical vertebra, thoracic apical vertebra, and T1. Additionally, the Cobb angles of major thoracic and lumbar curve were measured at different timepoints, and the correction rate was calculated. Furthermore, clinical photos of patients' back appearance were taken preoperatively and postoperatively. Results. Of the 278 patients reviewed, 29 met the inclusion criteria. The continuous follow-up of our study revealed an interesting occurrence. Criteria were established to define this finding, and the validity of the criteria was verified by a series of tests. The results of our study showed that the selective thoracic fusion was prone to cause left imbalance in patients with Lenke 1C AIS. Even though some patients regained spinal balance by postoperative spinal alignment remodelling, there were still about a third who remained imbalanced at 2 year follow-up. Smaller thoracic curve before surgery did not show higher risk of causing postoperative imbalance. Conclusions. Selective thoracic fusion is prone to cause left spinal imbalance in patients with Lenke 1C scoliosis. Postoperative spinal alignment remodelling can make some patients regain spinal balance. The postoperative spinal balance condition in patients with this disorder could be improved by selecting LIV at stable vertebrae or above, or by checking balance condition during surgery to prevent overcorrection. Additionally, to establish the presence of postoperative spinal alignment remodelling, the criteria we recommend is that thoracic apical vertebra shifts towards the right side by more than 5 mm 2 years after surgery