Aims

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.

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.

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Summary Statement

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.

Introduction: Degenerative disc desease is one of the most frequently encountered spinal disorders. The intervertebral disc is a complex anatomic and functional structure, which makes the development of an efficient artificial disc a challenge [1].

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 [2].

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).

Material and Methods: In-vitro flexibility testing on functional spinal units (FSU) out of 12 fresh frozen lumbar spines has been performed. The FSU (L2/L3 and L4/L5) were tested first in the native condition, followed by nucleotomy and partial annulus resection and also after TDA with activ L (lumbar artificial disc, Aesculap Germany).

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.

Results: The TDA with activ L leads to a good restoration of ROM and NZ in all loading directions under in-vitro flexibility testing. The instantaneous COR is exemplary described for the native condition under flexion/ extension in the sagittal plane. For the native condition the COR is located in the center of the inferior vertebral endplate. After nucleotomy the COR shifts dorsally into the region of the spinal cord and a significant grade of instability has been measured.

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.

Conclusion: The instantaneous COR has been estimated in-vitro for the different loading situations in the human lumbar spine before and after TDA. Based on the newly introduced method further optimizations of TDA devices can be undergone in regard to the particular aspect of physiological kinematics.

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).

Background: It is often useful to gauge the flexibility of curves while assessing patients with scoliosis. Our aim was to discover if there were any reliable x-ray predictors of stiffness.

Methods: Previously the flexibility index has been shown to be an accurate measure of curve stiffness. A random selection of fifty x-ray sets was analyzed for parameters that might predict flexibility. These were then compared to the flexibility index generated from bending films. We recorded age; Cobb angle; bending film Cobb angle; Perdriolle rotation assessment; percentage wedging of the apical vertebrae and translation of the apex of the curve from a central sacral/cervical line. We then calculated the flexibility index. All measurements were taken from immediately pre operative standing AP x-rays and fulcrum bending films (1). The group was then assessed as a whole and subgroups were analyzed. Large curves (> 50 degrees) were compared to small (< 50 degrees) curves and thoracic curves were compared with thoracolumbar curves. Correlation between the flexibility index and the other parameters was then studied. We used Pearson correlation coefficient for parametric data and the Spearman rank correlation coefficient to study the non parametric data. P values were then assigned using a statistics software package.

Results: Age and apical translation were not related to curve stiffness. The Cobb angle was the only strong predictor of flexibility (p-0.002) looking at all curve types together. The Cobb angle was, however, more useful in larger curves and did not reach statistical significance in the small curve subgroup. In small curves Perdriolle rotational assessment was a more useful measurement (p-0.02). In the thoracic curve subgroup the percentage wedge of the apical vertebrae was a strong predictor (p-0.007).

Conclusion: Our sample had a strong bias toward an adolescent age group (5–61) mean age 17 and probably did not have enough of a spread to demonstrate the previous relationship between age and stiffness (2). The study re enforces the value of the Cobb angle in predicting curve stiffness but suggests caution using it in smaller curves. It also suggests a role for Perdriolle measurement in small curves and percentage apical wedge in thoracic curves.

Aim:

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.

Introduction: Pre-operative coronal curve flexibility assessment is of key importance in the surgical planning process for scoliosis correction. The fulcrum bending radiograph is one flexibility assessment technique which has been shown to be highly predictive of potential curve correction using posterior surgery, however little is known about the extent to which soft tissue structures govern spinal flexibility. The aim of this study was to explore how the mechanical properties of spinal ligaments and intervertebral discs affect coronal curve flexibility in the fulcrum bending test. To this end a biomechanical analysis of a scoliotic thoracolumbar spine and ribcage was carried out using a three dimensional finite element model.

Methods: CT-derived spinal anatomy for a 14 year old female adolescent idiopathic scoliosis patient was used to develop the 3D finite element model. Physiological loading conditions representing the gravitational body weight forces acting on the spine when the patient lies on their side over the fulcrum bolster were simulated. Initial mechanical properties for the spinal soft tissues were derived from existing literature. In six separate analyses, the disc collagen fibre and ligament stiffness values were reduced by 10%, 25% and 40% respectively, and the effects of reduced tissue stiffness on fulcrum flexibility were assessed by comparison with the initial model. Finally, the effect of discectomy on fulcrum flexibility was simulated for thoracic levels T5 to T12.

Results: Reducing disc collagen fibre stiffness resulted in a greater change in segmental rotations in the fulcrum bending test than reducing ligament stiffness. However, reductions of up to 40% in disc collagen fibre stiffness and ligament stiffness produced no clinically measurable increase in fulcrum flexibility (increase of 1.2%). By contrast, following removal of the discs, the simulated fulcrum flexibility increased by more than 80% compared to the initial case.

Discussion: Disc collagen fibre and ligament stiffness both have minimal influence on scoliotic curve flexibility. However, discectomy simulation shows that the intervertebral discs are of critical importance in determining spinal flexibility.

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.

Introduction This in-vitro biomechanical study was undertaken to compare the multi-directional flexibility kinematics of single versus multi-level lumbar Charité reconstructions and determine the optimal biomechanical method for surgical revision – posterior instrumentation alone or circumferential spinal arthrodesis.

Methods A total of seven human cadaveric lumbosacral spines (L1 to Sacrum) were utilized in this investigation and biomechanically evaluated under the following L4-L5 reconstruction conditions: 1) Intact Spine; 2) Diskectomy Alone, 3) Charité, 4) Charité + Pedicle Screws, 5) Two Level Charité (L4-S1), 6) Two Level Charité + Pedicle Screws (L4-S1), 7) Charité L4-L5 with Pedicle Screws and Femoral Ring Allograft (L5-S1) and 8) Pedicle Screws and Femoral Ring Allograft (L4-S1). Multi-directional flexibility testing utilized the Panjabi Hybrid Testing protocol, which includes pure moments for the intact condition with the overall spinal motion replicated under displacement control for subsequent reconstructions. Hence, changes in adjacent level kinematics can be obtained compared to pure moment testing strategies. Unconstrained intact moments of ±7Nm were used for axial rotation, flexion-extension and lateral bending testing, with quantification of the operative and adjacent level range of motion (ROM) and neutral zone (NZ). All data was normalized to the intact spine condition.

Results In axial rotation, single and two level Charité reconstructions produced significantly more motion than pedicle screw constructs combined with the Charité or femoral ring allograft (p< 0.05). There were no differences between the Charité augmented with pedicle screws or pedicle screws with femoral ring allograft (p> 0.05). Similar trends were observed under flexion-extension and lateral bending conditions with the Charité reconstructions demonstrating no significant differences compared to the intact spine (p> 0.05). However, the Charité combined with pedicle screws or pedicle screws with femoral ring allograft significantly reduced motion at the operative level compared to the Charité reconstruction (p< 0.05). The most pronounced changes in adjacent level kinematics were observed at the inferior level. The addition of pedicle screw fixation, in all cases, increased segmental motion at the inferior adjacent level (L5-S1) compared to the intact and Charité reconstruction groups (p< 0.05).

Discussion Single and two level total disc arthroplasty using the Charité device preserved segmental motion at the operative and adjacent levels compared to pedicle screw stabilization constructs. In terms of revision strategies, posterior pedicle screw reconstruction combined with an existing Charité is not statistically different from pedicle screws combined with femoral ring allograft. As we enter an era of total disc replacement and the impending necessity for surgical revision, the current study provides a biomechanical basis for posterior re-stabilization alone in lieu of combined anteroposterior revision.

Introduction: There has been controversy in recent publications for/against the value of intraoperative traction views under anaesthesia, both studies had patients with a mean standing cobb angle of 55o failing to show the predictive value of these views for curves greater than 60o.

Design: Compare predictive value of fulcrum bending views with intraoperative forced traction under anaesthesia (FTUGA) views in predicting curve flexibility; influencing the correction of curves greater than 60^o in scoliosis deformity.

Subjects: 35 patients with idiopathic scoliosis undergoing surgical correction; mean age was 19 yrs (9–40), the student’s t test and χ2 were used to assess the reliability of FTUGA views in predicting curve flexibility, degree of correction the fulcrum bending correction index (FBCI) used to measure curve flexibility and correction.

Results: The mean preoperative major curve standing and fulcrum bending views Cobb angle was 72^o (50–90), 59^o (20–82) respectively, and 37^o (14–54) on traction views. Posterior correction was performed in all patients. The mean postoperative major curve Cobb angle was 27 (10–54). The number of patients predicted for combined anterior release and posterior instrumentation was reduced from 22 to 3.

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.

Conclusion: Forced Traction Under General Anaesthesia views were superior in predicting curve flexibility in curves that measured more than 70^o but weak predictor of final correction angle when performing posterior scoliosis correction.

Introduction

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.

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. Flexibility was assessed by modified Schober's test. Continuous variables were compared using student t-tests and categorical variables were compared using chi-square. The cohort included 19 patients each in group A and B . Group A had M:F distribution of 1:18 while group B had 2:17. The mean age in group A and group B were 14.8±2.9 and 15.3±3.1 years respectively. The mean follow-up of patients in groups A and B were 24.5±1.8 months and 27.4±2.1 months respectively. Mean pre-op thoracolumbar/lumbar (TL/L) cobbs for group A and group B were 55°±7° and 57.5°±8° respectively. At two years follow up, the cobbs for group A and B were 18.2°±3.6° and 17.6°±3.5° respectively (p=0.09). The average operating time for groups A and B were 169±14.2 mins and 219±20.5 mins respectively (p<0.05). The average blood loss of groups A and B were 105.3±15.4 and 325.3±120.4 respectively (p<0.05). The average number of instrumented vertebra between groups A and B were 6.2 and 8.5 respectively (p<0.05). The average LOS for NFASC and PSF was 3.3±0.9 days and 4.3±1.1 days respectively (p<0.05). No statistically significant difference in SRS 22 score was noted between the two groups. No complications were recorded. Our study shows no significant difference in PSF and NFASC in terms of Cobbs correction and SRS scores, but the NFASC group had significantly reduced blood loss, operative time, and fewer instrumented levels. NFASC is an effective alternative technique to fusion to correct and stabilize Lenke 5 AIS curves with preservation of spinal motion

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 Flexibility in 30∗ flexion).for checking balanced medial and lateral subtle laxity (playing), I have used simple blade with 1 & 2 mm thickness in each ends for younger patients, and the other one with 3&4 mm thickness in elder cases. Results. Average follow up period is 234.45 days. Average Operating time was 1: 32 (h:m). Average Transfusion = 1.22 unit packed cell. No Flexibility in 30∗ flexion was seen in 3 patients. Average varus malalignment =15.29∗ (2-25∗)/Av. Valgus angle = 7.19∗ (5-10 ∗)/Av. DLFA = 90.47∗ (87-93∗)/Av. PMTA = 83.41∗ (77-88.5∗)/Av. Ext. rotation cut = 3.11∗. Stage l + PCL + Post. Med. Capsular release was performed in 82.61%./Av. Post op alignment: 1.8 ∗ varus (0 -6 ∗) (worse in medial pivot knee). Av. Polyethylen size: 12.4 (9 in oxynium -19 in plus)/Semi membranous release was necessary in 4 cases (preop varus 17,20,24,25∗) (Post. Op varus 1,6,4,2)./S.MCL release was mandatory in 2 cases (preop varus 17, 24 ∗ & No Flexibility in 30∗ flexion) (Post. Op varus: 1, 4 ∗). pre operation knee society score: stage I = 27.8, stage II = 37.9 increase to stage I = 85.47, stage II = 75.65. Conclusion. In society with more kneeling habitués, during performing total knee arthroplasty with less than 25∗ degree varus malalignment plus some degree flexibility of the deformity in flexion, it is wise to consider posteromedial capsular release prior to semi membranous & S.MCL release to obtain full correction of alignment. But the most important things is reaching to full align limb regardless of which chosen technique

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. Flexibility tests were first carried out on the intact specimen, followed by 3 randomized surgical conditions without cement and lastly the 3 conditions after cement augmentation. The 3 conditions were: 1) no posterior extension rods to L1, 2) flexible extension rods, and 3) rigid extension rods. A combined testing/analysis protocol that used both the traditional flexibility method and a hybrid technique [Panjabi 2005] was adopted. Flexibility tests with +/−5 Nm pure moments in flexion-extension, axial rotation and lateral bending were carried out and vertebral bodies’ motion in 3-D were collected. Two-way repeated measures ANOVA analyses were carried out on ROM between cement augmentation (factor 1) and the posterior rod extension (factor 2) on each flexibility test direction. An alpha of 0.05 was chosen. Newman-Keuls post-hoc analyses were carried out to compare between surgical techniques. Results: Using the flexibility protocol, a reduction in ROMs at the destabilized level was observed with cement augmentation of screws or extension with rigid or flexible posterior rods to adjacent distal level. With the hybrid protocol, ROMs at adjacent level (T12-L1) were reduced with rod extension, but not with cement. Conclusions: The results of this study suggest that cement augmentation would enhance stabilization, but create possible adjacent level effects due to increased motion and strain, while additional flexible extension rods would reduce biomechanical changes at the level of extension. Funding: 2 Funding Parties: CIHR

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. Flexibility with the data set. The system will be demonstrated in the course of the presentation. The perceived advantages over a paper system , validation, “windows anywhere” and confidentiality will be discussed. The adaptability of the system for use in outpatients and for the production of operation notes will be outlined. The cost, about £700, per unit plus software charges will be discussed

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. Flexibility at individual disc level was measured as the differences between flexion/extension angles accurate to within 1°. Motion was evaluated at the index and immediate adjacent levels. Results: Patients with single level Dynesys had an average ROM of (3+/−4.7) at L5-S1 and (5.1+/−2.9) at the immediate adjacent level. Two levels Dynesys was associated with a ROM of 5+/−3.6 at L5-S1 & L4–5 and 3.5+/−1.8 at their immediate neighbour disc. Across three levels, Dynesys favoured a ROM of 5.3+/−2.5 at the operated sites and 1.6+/− 2 at the adjacent level. Discussion & Conclusion: This study is the first radiological research to confirm the flexibility of Dynesys. Controlled motion at the dynesys treated disc levels share to distribute global spinal movements. This will advantage the next disc segments and protects them from risk of developing “accelerated adjacent segment disease”

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 (https://www.ideal-collaboration.net/). Adherence to the framework would provide a robust evidence-based mechanism for developing trust in AI applications, where the underlying algorithms are unlikely to be fully understood by clinical teams.

Cite this article: Bone Joint Res 2024;13(9):507–512.

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: Flexibility obtained at traction radiographs with the patient conscious and UGA is clearly better in numerical values, and closer to the amount of surgical correction than the amount of flexibility at three-points lateral pressure radiographs and side-bending radiographs. This method benefits patients by allowing them to avoid anterior release surgery, assessing the fusion levels and helps predict postoperative correction. Longer follow ups are needed to see whether there is decompensation or not