The aim of this study was to assess the ability of morphological spinal parameters to predict the outcome of bracing in patients with adolescent idiopathic scoliosis (AIS) and to establish a novel supine correction index (SCI) for guiding bracing treatment. Patients with AIS to be treated by bracing were prospectively recruited between December 2016 and 2018, and were followed until brace removal. In all, 207 patients with a mean age at recruitment of 12.8 years (SD 1.2) were enrolled. Cobb angles, supine flexibility, and the rate of in-brace correction were measured and used to predict curve progression at the end of follow-up. The SCI was defined as the ratio between correction rate and flexibility. Receiver operating characteristic (ROC) curve analysis was carried out to assess the optimal thresholds for flexibility, correction rate, and SCI in predicting a higher risk of progression, defined by a change in Cobb angle of ≥ 5° or the need for surgery.Aims
Methods
Back pain is a significant socio-economic problem affecting around 80% of the population at some point during their lives. Chronic back pain leads to millions of days of work absence per year, posing a burden to health services around the world. In order to assess surgical interventions, such as disc replacements and spinal instrumentations, to treat chronic back pain it is important to understand the biomechanics of the spine and the intervertebral disc (IVD). A wide range of testing protocols, machines and parameters are employed to characterise the IVD, making it difficult to compare data across laboratories. The aim of this study was to compare the two most commonly used testing protocols in the literature: the stiffness and the flexibility protocols, and determine if they produce the same data when testing porcine specimens in six degrees of freedom under the same testing conditions. In theory, the stiffness and the flexibility protocols should produce equivalent data, however, no detailed comparison study is available in the literature for the IVD, which is a very complex composite structure. Tests were performed using the unique six axis simulator at the University of Bath on twelve porcine lumbar functional spinal unit (FSU) specimens at 0.1 Hz under 400 N preload. The specimens were divided in two groups of six and each group was tested using one of the two testing protocols. To ensure the same conditions were used, tests were firstly carried out using the stiffness protocol, and the equivalent loading amplitudes were then applied using the flexibility protocol. The results from the two protocols were analysed to produce load-displacement graphs and stiffness matrices. The load-displacement graphs of the translational axes show that the stiffness protocol produces less spread between specimens than the flexibility protocol. However, for the rotational axes there is a large variability between specimens in both protocols. Additionally, a comparison was made between the six main diagonal terms of the stiffness matrices using the Mann-Whitney test, since the data was not normally distributed. No statistically significant difference was found between the stiffness terms produced by each protocol. However, overall the stiffness protocol generally produced larger stiffnesses and less variation between specimens. This study has shown that when testing porcine FSU specimens at 0.1 Hz and 400 N preload, there is no statistically significant difference between the main diagonal stiffness terms produced by the stiffness and the flexibility protocols. This is an important result, because it means that at this specific testing condition, using the same testing parameters and environment, both the stiffness and flexibility methods can be used to characterise the behaviour of the spine, and the results can be compared across the two protocols. Future work should investigate if the same findings occur at other testing conditions.
Chronic back pain is the leading cause of disability worldwide, affecting millions of people. The source of pain is usually the intervertebral disc (IVD), thus there has been a growing interest in developing new improved implants such as disc replacements to treat the condition. However, to ensure the artificial devices being designed replicate the intact disc, the biomechanical behaviour of the IVD must be well understood (Adams and Dolan, 2005). The two most widely used testing procedures in the spinal industry to characterise the behaviour of the disc are the flexibility and the stiffness protocols (Stokes et al, 2002 and Panjabi et al, 1976). For elastic specimens, the results produced by the flexibility and the stiffness protocols should in theory be identical. However, this does not hold true for inelastic specimens, such as the IVD. For this reason, the custom developed Spine Simulator (Holsgrove et al, 2014) at the University of Bath has been used to compare, in six degrees of freedom, the extent of the difference produced by these two testing protocols. A biomechanical model of the IVD was tested, which consisted of two cylindrical nylon blocks attached together with a layer of nitrile rubber, representing respectively the vertebral bodies (VB) and the IVD. Two steel pins were inserted into the VB, spanning the thickness of the disc, to ensure the stiffness raise either side of the neutral zone was replicated by the model. Tests were performed at a frequency of 0.1 Hz using triangular wave cycles. The specimen was firstly subjected to the stiffness protocol, characterised by displacements of ±0.5 mm in anterior-posterior and lateral shear, ±0.35 mm in axial compression and ±1.5 deg in all rotational axes. The resulting loads were applied to the specimen when subjected to the flexibility protocol. In addition, the effect of a preload was studied by testing specimens with an axial compressive load of 250 N. The stiffness matrix was calculated for each test and the main diagonal terms produced for the two protocols were compared using the Mann-Whitney test. Overall, results showed that there was a significant difference in the stiffness terms produced by the two protocols when tests were performed with (p ≤ 0.016) and without (p = 0.004) a preload. The only exception was found in the flexion-extension axis when the test was performed with a preload (p = 0.337). Additionally, differences were also recorded when comparing the shape and linearity of the load-displacement hysteresis curve (Figure 1) and the area enclosed by the curve. This preliminary study has provided important information regarding the differences in the data produced by the flexibility and the stiffness protocols, it is therefore impractical to compare results produced using these two methods. To ensure that in the future results can be compared across laboratories, there is a need for a standardised testing procedure in the spinal industry.
Spinal flexibility in bending and axial torque has been shown to exhibit very modest changes with advancing disc degeneration. This study is the first to address the possible relationship in pure anterior shear and no clear relationship was observed. Disc degeneration (DD) is a risk factor for low back pain. Stable or unstable spine segments may be treated with an isolated decompression or instrumented stabilization, respectively. The effect of DD on spinal flexibility has been addressed by several groups in bending but not in shear; a highly relevant load direction in the lumbar spine is anterior shear. The objective of our study was to determine the effect of DD on anterior translation and specimen stiffness under shear loading in an Summary Statement
Introduction
Based on the complexity of the anatomical structures and the nearly unknown loading conditions at the moment only contradictory knowledge exists about the kinematics after TDA and in particular the location of the center of rotation in the human lumbar spine [ The objective of our study was to evaluate the kinematics of the human lumbar spine and the ability of TDA to restore the native conditions in regard to range of motion (ROM), neutral zone (NZ) and center of rotation (COR).
Therefore a spinal simulator has been customized, applying pure moments for flexion/extension, lateral bending and axial rotation (+/−7.5Nm) and axial preload (FP=400N) with a defined velocity (1°/s). The instantaneous COR has been calculated based on the velocity pole method using a 3D ultrasonic motion analysis system, measuring the twelve components of motion.
After insertion of the lumbar artificial disc the instability can be reduced to the native grade of motion and the COR is located again in the main axis of the spinal column in the upper third of the inferior vertebra.
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). A comprehensive search was conducted by two independent reviewers on PubMed, Embase, Medline, and Web of Science to obtain all published information on morphological predictors of AIS progression. Search items included ‘adolescent idiopathic scoliosis’, ‘progression’, and ‘imaging’. The inclusion and exclusion criteria were carefully defined. Risk of bias of studies was assessed with the Quality in Prognostic Studies tool, and level of evidence for each predictor was rated with the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach. In all, 6,286 publications were identified with 3,598 being subjected to secondary scrutiny. Ultimately, 26 publications (25 datasets) were included in this review.Aims
Methods
The Lenke Classification for adolescent idiopathic scoliosis (AIS) classifies curves as nonstructural if they reduce to less than 25° on bending radiographs. We aimed to establish whether there is a significant difference in curves assessed as structural/ nonstructural when comparing bending radiographs to forced traction radiographs. We undertook a retrospective database review of 100 consecutive AIS patients having undergone surgical correction by the 2 senior authors, together with radiographic review. Curves were classified according to the Lenke system including modifiers. Magnitude of the minor curves were compared on plain PA standing radiographs, bending radiographs and forced traction radiographs.Aim:
Methods:
We described a technique of measuring the flexibility of the rib prominence clinically before surgery, and aimed to analyse the results in patients with adolescent idiopathic scoliosis who underwent posterior correction with pedicle screw instrumentation. This prospective study investigated the magnitude of rib humps before and after the operation when the patient was in Adam's forward bending posture. Also preoperatively, a flexion and derotation manoeuvre was performed and the corrected rib prominence was measured. This is compared to the magnitude of the rib hump present postoperatively at three months' follow up. Seven consecutive patients with adolescent idiopathic scoliosis that underwent posterior surgical correction. Clinical measurement of rib prominence using scoliometer. The magnitude of the curve improved from a mean preoperative Cobb angle of 53.6+/−11.2° (range 45.3–72.5°) to a mean postoperative Cobb angle of 7.8+/−9.3° (range 0.4–17.6°). The mean preoperative magnitude of the rib hump was 12.3+/−6.9° (range 5-20°) which was then corrected to a mean magnitude of 1.3+/−2.2° (range 0-5°) by performing the above described flexion derotation manoeuvre. The mean postoperative magnitude of the rib hump was 3.0+/−3.1° (range 0-8°) with the patient in Adam's forward bend position. There was positive correlation between the postoperative residual rib hump and the reduced rib hump measured preoperatively using our described technique (r=0.8,p=0.05). This flexion derotation test is a useful in assessing the amount of postoperative persistent rib hump after posterior correction of adolescent idiopathic scoliosis using pedicle screw instrumentation with derotation technique.
Predictive value for traction view according to standing Cobb angle was P=0.1 for Cobb angles (50–59), P=0.1 for Cobb angles (60–69), P= 0.01 for Cobb angle (70–79), P=0.01 for Cobb angle (80–90). P value for the difference between fulcrum bending views, traction views and post op correction P=0.001 in favour of traction views, the mean curve flexibility was 33%, 55% for fulcrum and traction respectively. Mean fulcrum bending and traction correction index were 232%, 123% respectively.
With the use of each pedicle screw for surgical correction of adolescent idiopathic scoliosis (AIS), there is an increase in instrumentation-related costs, operative time, risk of neural injury, and overall health-care expenses. As such, alternate level screw strategy (ALSS) has been reported as a potential alternative to contiguous multilevel screw strategy (CMSS). Moreover, studies have shown the importance in accounting for the flexibility of the curve based on the fulcrum bending radiograph when assessing postoperative curve correction. Therefore, this study addressed a radiographic and cost analysis comparing CMSS with ALSS for the treatment of thoracic AIS with titanium screws and rod application. 77 patients with AIS underwent surgery (range 6–15 levels). 35 patients received CMSS, which was characterised as bilateral screw fixation at every level. 42 patients underwent ALSS, which entailed bilateral screw fixation at alternate levels. Titanium rods were used in all cases. Preoperative and postoperative posteroanterior and fulcrum bending radiographic Cobb angles were obtained for all patients. The fulcrum flexibility and the fulcrum bending correction index (FBCI) were assessed. Cost analysis was also done.Introduction
Methods
The current study aims to compare the clinico radiological outcomes between Non-Fusion Anterior Scoliosis (NFASC) Correction and Posterior Spinal Fusion (PSF) for Lenke 5 curves at 2 years follow up. Methods:38 consecutive Lenke 5 AIS patients treated by a single surgeon with NFASC (group A) or PSF (group B) were matched by age, Cobb's angle, and skeletal maturity. Intraoperative blood loss, operative time, LOS, coronal Cobbs, and SRS22 scores at 2 years were compared.
Background. Performing total knee replacement needs both bony & soft tissue consideration. Late John Insall advocating spacer blocks with concept of balanced & equal flexion – extension Gap. Although we usually excise both ACL & PCL, still it is possible to retain more soft tissue. Both PCL retaining & sacrificing Require intact collaterals for stability. Superficial MCL & LCL should be preserved, if possible. after PCL removal the following advantages could obtain: More correction of fixed varus or valgus deformity, More surgical exposure. but there are no proved disadvantages like; increasing in stress & loosening of bone-cement-prosthesis interface, specific clinical difference in ROM, forward lean during stepping up, proprioception inferiority. in other hand Over tight PCL cause excessive rollback of tibia & knee hinges open, preventing flexion (booking), and Severe posteromedial poly wear in poor balance PCL might be happened. Mid range laxity when Post. Capsule is tight, even with correct tensioning in full extension & 90 degree flexion, may occur (and secondary collateral ligaments imbalance throughout ROM). There is a major effect of capsular contracture in coronal mal alignment with flexion contracture. Full MCL releases not only correct fixed varus but also open the medial space in flexion. MCL & post. Capsule has combined valgus resistant effect in extension. PCL release increase flexion gap more, May be necessary to release something that affect extension gap as compensated balancing (Post.medial capsule). Any flexion contracture need to posterior capsulotomy & post. Condyle osteophyte removal before femoral recut. So it is possible to perform posteromedial capsulotomy prior to superficial MCL release. Method. From May to Dec. 2009, 22 patients (23 knees) with primary DJD and varus deformity of knees were operated by myself with joint replacement. most patients had some degree of varus correction in flexion, passively. the varus angle was less than 25∗, means mild to severe but not decompensated. For soft tissue balancing during Total knee arthroplasty I consider the following steps;. Medial capsule & deep MCL release, PCL release, Posteromedial capsulotomy, semimembranous release, Superficial MCL release, Pes anserinous release. Post. medial capsulotomy was done in all cases. The Average Age was 64.74 years, 19 patients were female (83%) and one of them had bilateral TKA simultaneously. Lt Knee was operated in 14 cases (70% of 24). Spinal anesthesia was applied in 82%. 10 patients were operated with MIS technique and 13 patients with Standard medial parapatellar incision. Semi membranous release was necessary in 4 cases (preop varus 17,20,24,25∗). MCL release was mandatory in 2 cases (preop varus 17, 24 ∗ & No
Purpose: The objectives of this study were to determine the effect of posterior instrumentation extension and/or cement augmentation on immediate stabilization of the instrumented level and biomechanical changes adjacent to the spinal instrumentation. Methods: This study was designed for repeated measures comparison, using 12 T9-L3 human cadaveric segments, to test the effects of posterior rod extension and cement augmentation following T11 corpectomy. The spine was stabilized with a vertebral body replacement device and with posterior instrumentation from T10 to T12. The T12 pedicle tracts were over-drilled to simulate loosened screws in an osteoporotic spine. The T10 screws were not over-drilled but cemented so as to keep the superior segments constant.
A computer system has been developed that allows rapid collection of data about joint replacements in the operating room which can then be transmitted to a server via the internet for later analysis. The programme comprises three main fields, a demographic field, an implant field and a field to allow specific questions. The specific features include:-. An unique programme linking the manufacturer’s barcodes in a readable form. A reminder system that only allows logging of the data when all the questions are answered.
Introduction: In this study we have studied the range of motion within Dynesys treated discs and levels adjacent to flexible stabilisation. Dynesys was designed to offer physiological motion at the lumbar spine. An advantage which is superior to abolishing movements through spinal fusion. Methods: A cohort of 75 post-Dynesys patients had weight-bearing lateral lumbar spine x rays in flexion/extension positions. Evaluation was done through PACS™ digital software.
Despite the vast quantities of published artificial intelligence (AI) algorithms that target trauma and orthopaedic applications, very few progress to inform clinical practice. One key reason for this is the lack of a clear pathway from development to deployment. In order to assist with this process, we have developed the Clinical Practice Integration of Artificial Intelligence (CPI-AI) framework – a five-stage approach to the clinical practice adoption of AI in the setting of trauma and orthopaedics, based on the IDEAL principles ( Cite this article:
Aim: Assessment of curve flexibility is important in decision making before surgical correction of scoliosis. Supine bending radiographs are presently the gold standard technique by which flexibility is assessed, but their reliability has been questioned. Our aim was to compare the usefulness of supine side bending and traction radiographs (with new electronic traction table) in assessing curve flexibility, examining the correlation of each technique with postoperative correction, determining fusion levels in patients undergoing posterior spinal fusion. Material and Method: 25 patients required surgical treatment with idiopathic scoliosis were evaluated prospectively. Thirteen were female. The average age was 12.87 years. Preoperative radiologic evaluation consisted of standing anteroposterior, lateral, supine lateral bending and traction graphs by electronic traction table. We designed a new electronic traction table in order to take the longitudinal traction and three-points lateral pressure radiographs. We situated the patient on the table and measured the patient’s weight. Then we made a longitudinal and lateral traction while asking the possible neurologic symptoms. If there was not any symptom we stopped at the seventy percent of the patient’s weight for the longitudinal and at the fifty percent for the lateral pressure. These radiographs had been taken before and under general anesthesia (UGA). The correction obtained in the Cobb angle between the bending and traction radiographs was compared. The influence of the traction radiography on the decision for surgery and its correlation with postoperative result was examined. Results: Longitudinal traction radiographs taken consciously provided the best amount of flexibility, with no significant difference from traction with the patient UGA (p = 0.17) but with significant difference from bending radiographs (p <
0.002). Better flexibility in traction radiographs helped us eliminate the need for anterior release in 5 patients. We decreased the fusion levels proximally or distally after all in 12 patients. No significant difference was demonstrated between the traction radiography and postoperative correction (P = 0.14). Conclusion: