Evaluation of a new sagittal classification system in adolescent idiopathic scoliosis

The effect of Providence night-time bracing on the sagittal profile in adolescent idiopathic scoliosis

PURPOSE

Adolescent idiopathic scoliosis (AIS) is characterized by coronal scoliosis and often a sagittal hypokyphosis. The effect of bracing on the sagittal profile is not well understood. The aim of this study is to assess the effect of night-time bracing on the sagittal profile in patients with AIS.

METHODS

We retrospectively included AIS patients with a main curve of 25-45° treated with a night-time brace in our institution between 2005 and 2018. Patients with estimated growth potential based on either Risser stage, hand X-rays, or menarchal status were included. Coronal and sagittal radiographic parameters were recorded at both brace- initiation and -termination. Patients were followed until surgery or one year after brace termination. Results were compared to a published cohort of full-time braced patients.

RESULTS

One hundred forty-six patients were included. Maximum thoracic kyphosis (TK) increased 2.5° (± 9.7) (p = 0.003), corresponding to a 3.5-fold relative risk increase post bracing in TK compared to a full-time brace cohort. Twenty-seven percent (n = 36) of the patients were hypokyphotic (T4/T12 < 20°) at brace initiation compared with 19% (n = 26) at brace termination (p = 0.134). All other sagittal parameters remained the same at follow-up. We found no association between progression in the coronal plane and change in sagittal parameters.

CONCLUSION

This is the first study to indicate that night-time bracing of AIS does not induce hypokyphosis. We found a small increase in TK, with a substantially lower risk of developing flat back deformity compared to full-time bracing. The coronal curve progression was not coupled to a change in TK.

Patient-Specific Surgical Correction of Adolescent Idiopathic Scoliosis: A Systematic Review

The restoration of sagittal alignment is fundamental to the surgical correction of adolescent idiopathic scoliosis (AIS). Despite established techniques, some patients present with inadequate postoperative thoracic kyphosis (TK), which may increase the risk of proximal junctional kyphosis (PJK) and imbalance. There is a lack of knowledge concerning the effectiveness of patient-specific rods (PSR) with measured sagittal curves in achieving a TK similar to that planned in AIS surgery, the factors influencing this congruence, and the incidence of PJK after PSR use. This is a systematic review of all types of studies reporting on the PSR surgical correction of AIS, including research articles, proceedings, and gray literature between 2013 and December 2023. From the 28,459 titles identified in the literature search, 81 were assessed for full-text reading, and 7 studies were selected. These included six cohort studies and a comparative study versus standard rods, six monocentric and one multicentric, three prospective and four retrospective studies, all with a scientific evidence level of 4 or 3. They reported a combined total of 355 AIS patients treated with PSR. The minimum follow-up was between 4 and 24 months. These studies all reported a good match between predicted and achieved TK, with the main difference ranging from 0 to 5 degrees, p > 0.05, despite the variability in surgical techniques and the rods' properties. There was no proximal junctional kyphosis, whereas the current rate from the literature is between 15 and 46% with standard rods. There are no specific complications related to PSR. The exact role of the type of implants is still unknown. The preliminary results are, therefore, encouraging and support the use of PSR in AIS surgery.

A bibliometric review and visual analysis of orthotic treatment in adolescent idiopathic scoliosis from the Web of Science database and CiteSpace software

Orthotic treatment has been the primary nonoperative treatment for patients with adolescent idiopathic scoliosis (AIS), however, no bibliometric study has been conducted in this field to date. Therefore, this study aims to analyze potential trends and new advances in the field of orthotic treatment of AIS through a bibliometric analysis and visualization study. Relevant literature included in the Web of Science database from the start of the database to the 1st month of 2023 was retrieved and analyzed using CiteSpace software (version 6.1.R6). Data on the nations, institutions, authors, journals, keywords, and cited references were collected for each publication. A total of 1005 records were included. The most productive countries and institutions were the USA and Hong Kong Polytechnic University, respectively. Spine was the most influential journal, with the highest number of citations. Hubert Labelle had the most publications, whereas Weinstein was the most cited author. The efficacy of orthotic treatment has always been at the frontier of research. Notably, changes in the quality of life after orthotic treatment, success rate or curve progression, new classification systems, and exercises have been the focus of research in recent years. This study enriches the understanding of research landscapes and key contributors in orthotic treatment for AIS.

Surgical strategy and outcomes for thoracolumbar disc herniation with Autologous Bone-Fusion or Cage-Fusion surgery: case series and literature review

To analyze the clinical characteristics and surgical outcomes of TLDH with Autologous Bone-Fusion for T10-L1 TLDH or Cage-Fusion for T12-L3 TLDH. This is a retrospective multi-center clinical study, involving a total of 43 patients with TLDH who underwent surgery in our institutions from December 2013 to January 2021. In all, 15 of 43 patients (34.9%) with T10-11(2)/T11-12(5)/T12-L1 (8) TLDH underwent Autologous Bone-Fusion surgery and 28 of 43 patients (65.1%) with T12-L1(3)/L1-L2(12)/L2-L3(13) TLDH underwent Cage-Fusion surgery. Demographic data, clinical characteristics and perioperative outcomes were recorded. During the follow-up, pre- to post-operative ODI, VAS back and leg pain scores significantly decreased (P1.2 = 0.001) and the score changes had no significant difference between two groups (P3 = 0.81, 0.59, 0.68). The intraoperative blood loss and operation time showed no significant difference between two groups (P = 0.056, 0.072). The patients showed prominent improvement of hypokinesia and satisfactory rate in two groups (5/7, 71.4% VS 9/12, 75.0%, P = 0.633; 11, 73.3% VS 25, 89.3%, P = 0.281). Notably, no recurrence and severe complications were reported. The choice of surgery approach should be individualized by clinical characteristics and radiology. Selectively Autologous Bone-Fusion for T10-L1 TLDH or Cage-Fusion for T12-L3 TLDH provided adequate nerve decompression and immediate stability. The overall fusion surgical outcomes were satisfactory without major complications during follow-up.

Specific sagittal alignment patterns are already present in mild adolescent idiopathic scoliosis

PURPOSE

The complex three-dimensional spinal deformity in AIS consists of rotated, lordotic apical areas and neutral junctional zones that modify the spine's sagittal profile. Recently, three specific patterns of thoracic sagittal 'malalignment' were described for severe AIS. The aim of this study is to define whether specific patterns of pathological sagittal alignment are already present in mild AIS.

METHODS

Lateral spinal radiographs of 192 mild (10°-20°) and 253 severe (> 45°) AIS patients and 156 controls were derived from an international consortium. Kyphosis characteristics (T4-T12 thoracic kyphosis, T10-L2 angle, C7 slope, location of the apex of kyphosis and of the inflection point) and sagittal curve types according to Abelin-Genevois were systematically compared between the three cohorts.

RESULTS

Even in mild thoracic AIS, already 49% of the curves presented sagittal malalignment, mostly thoracic hypokyphosis, whereas only 13% of the (thoraco) lumbar curves and 6% of the nonscoliosis adolescents were hypokyphotic. In severe AIS, 63% had a sagittal malalignment. Hypokyphosis + thoracolumbar kyphosis occurred more frequently in high-PI and primary lumbar curves, whereas cervicothoracic kyphosis occurred more in double thoracic curves.

CONCLUSIONS

Pathological sagittal patterns are often already present in curves 10°-20°, whereas those are rare in non-scoliotic adolescents. This suggests that sagittal 'malalignment' patterns are an integral part of the early pathogenesis of AIS.

Analysis of sagittal profile and radiographic parameters in symptomatic thoracolumbar disc herniation patients

BACKGROUND

Few studies describe thoracolumbar disc herniation (TLDH) as an isolated category, it is frequently classified as the lower thoracic spine or upper lumbar spine. Thus, less is known about the morphology and aetiology of TLDH compared to lumbar disc herniation (LDH). The aim of study is to investigate sagittal alignment in TLDH and analyze sagittal profile with radiographic parameters.

METHODS

Data from 70 patients diagnosed with TLDH were retrospectively reviewed. The thoracic-lumbar alignment was depicted by description of curvatures (the apex of lumbar curvature, the apex of thoracic curvature, and inflexion point of the two curvatures) and radiographic parameters from complete standing long-cassette spine radiographs. The rank sum test was utilised to compare radiographic parameter values in each subtype.

RESULTS

We found two subtypes differentiated by the apex of thoracic kyphotic curves. The sagittal profile was similar to that of the normal population in type I, presenting the apex of the thoracic kyphotic curve located in the middle thoracic spine. The well aligned thoracic-lumbar curve was disrupted in type II, presenting the apex of the thoracic kyphotic curve located in the thoracolumbar region in type II patients. Thirty-six patients were classified as type I, and 34 patients were classified as type II. The mean sagittal vertical axis, T1 pelvic angle and L1 pelvic angle were 27.9 ± 24.8°, 8.2 ± 7.3° and 6.2 ± 4.9°, respectively. There was significant difference (p < 0.001) of thoracolumbar angle between type I (14.9 ± 7.9°) and type II patients (29.1 ± 13.7°).

CONCLUSIONS

We presented two distinctive sagittal profiles in TLDH patients, and a regional kyphotic deformity with a balanced spine was validated in both subtypes. In type I patients, disc degeneration was accelerated by regional kyphosis in the thoracolumbar junction and eventually caused disc herniation. In type II patients, excessive mechanical stress was directly loaded at the top of the curve (thoracolumbar apex region) rather than being diverted by an arc as in a normal population or type I patients. Mismatch between shape and sacral slope value was observed, and better agreement was found in Type II patients.

The heritability of coronal and sagittal phenotype in idiopathic scoliosis: a report of 12 monozygotic twin pairs

PURPOSE

One of the pathways through which genetics may act in the causation of idiopathic scoliosis is inheritance of a specific sagittal profile that predisposes for its development. In this study, coronal and sagittal parameters were compared in an international collection of monozygotic twins with idiopathic scoliosis.

METHODS

Twelve monozygotic twin pairs who underwent biplanar radiography for idiopathic scoliosis were systematically identified in existing scoliosis databases in The Netherlands, Sweden, and Denmark. On the first available radiographs, the coronal and sagittal curve parameters (Roussouly and Abelin types, thoracic kyphosis, lumbar lordosis and length of the posteriorly inclined segment) were determined.

RESULTS

In all 12 monozygotic twin pairs, both twins were affected by AIS. Four (33%) twin pairs had similar coronal and sagittal spinal phenotype, whereas two (17%) had different coronal phenotype and similar sagittal profiles, and six (50%) pairs had different coronal as well as sagittal phenotype.

CONCLUSIONS

Analysis of biplanar curve characteristics in monozygotic twins showed that all twin pairs were affected by idiopathic scoliosis. However, only 33% of the pairs had similar coronal and sagittal spinal phenotypes. Based on this limited dataset, the hypothesis can be formulated that besides genetic pre-disposition, the individual (inherited) sagittal profile plays a role in the development of different coronal curve type.

Pitfalls in assessing limb alignment affected by rotation and flexion of the knee after total knee arthroplasty: Analysis using sagittal and coronal whole-body EOS radiography

BACKGROUND

Inappropriate posture during radiographic assessment may lead to misunderstanding of postoperative alignment after total knee arthroplasty (TKA). The EOS system assesses coronal and sagittal alignment simultaneously. This study aimed to evaluate the effect of flexion and/or rotation on alignment, and identify the patterns of knee posture with serial follow-up using the EOS system.

METHODS

One-hundred and fifteen patients of TKA and serial whole-body EOS were included. The hip-knee-ankle (HKA) angle in the coronal and sagittal planes, femoral component rotation ratio (FCR), tibial component rotation ratio (TCR), and fibular overlap ratio (FO) were measured immediately and at six months and one year postoperatively. Total and partial correlation, using flexion and rotation as a control variable was performed.

RESULTS

The mean HKA values and flexion immediately post-operation were different compared with the values noted at six months and one year postoperatively (for all, P < 0.05). The FCR and FO were correlated with the HKA angle during all periods (for both, P < 0.05). The Pearson correlation coefficients of the HKA angle with rotation parameters decreased when flexion was controlled.

CONCLUSIONS

Combined rotation and flexion of the knee joint has a greater effect on coronal alignment compared with isolated flexion or rotation and was more frequently observed during the early postoperative period. Therefore, surgeons should be made aware of the potential knee rotation and flexion errors after TKA.