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The aim of our study was to evaluate the impact of an internist physician specialized in diabetes, appointed as an in-house physician in the orthopedic wards, on improving clinical outcomes and in particular 30-day mortality. We analyzed a cohort of patients hospitalized more than 24 h in the orthopedic service. The analyses included a comparative analysis between the pre- and post-intervention time periods and an interrupted time series (ITS) analysis, which were conducted in stratification to three populations: whole population, patients with at least one chronic disease and/or older than 75 years of age and patients diagnosed with diabetes. The primary outcome was 30-day mortality following the hospitalization. A total of 11,546 patients were included in the study, of which 19% (2212) were hospitalized in the post intervention period. Although in the comparative analysis there was no significant change in 30-day mortality, in the ITS there was a decrease in the mortality trend during the post intervention period in the entire and chronic disease/elderly populations, compared to no change during the pre-intervention period: a post-intervention slope of − 0.14(p value

INTRODUCTION Rib fracture fixation is becoming more popular and widely accepted among trauma surgeons worldwide as the recommended treatment method for flail chest injury. Recent data demonstrate improved results when compared with non-operative treatment. Improved outcomes were reported regarding ICU stay, need for tracheostomy, length of hospital stay, ventilator-associated pneumonia (VAP), and even death. The objective of this study was to ascertain whether clinical respiratory para-meters are improved after rib fracture fixation procedure. MATERIAL AND METHODS This is a prospective study using a retrospective cohort for control, which took place at the Soroka University Medical Centre, Israel. Inclusion criteria included all patients over 18 years of age with flail chest injury or multiple ribs fractures, who were admitted to the General Intensive Care Unit (GICU). Between October 2015 and December 2018, we identified 24 patients who had their rib fractures operatively fixed and compared them to 61 patients with flail chest and multiple rib fractures, who were admitted to our GICU between the years 2010 and 2015 and were treated non-opera-tively. In all the surgical cases operations were performed within 72 hours of arrival in accordance with our treatment algorithm. All fractures were fixed using specialised anatomic locking plates/nails. Demographic data were collected, and respiratory parameters before and after the surgery were recorded and analysed. RESULTS We compared patients who had had their rib fractures fixed with a cohort group of patients who had been treated non-operatively in the past. No demographic differences were found between the 2 groups, nor were there any differences in their clinical trauma scoring, mechanical ventilation days, length of ICU stay, VAP, and death rates. The respiratory parameters (paO2/FiO2 ratio and chest wall compliance) were significantly higher during the 3 ensuing days after surgery and continued to improve in Group 1 (rib fixation group), in comparison to group 2 (non-operative) patients (P = 0.007 and P < 0.0001, respectively). The peak inspiratory pressure and PEEP para-meters were significantly lower in group 1 in comparison to group 2 during the 3 days, in favour of the operated group, with significant improvement noted over the 3 days post-surgery (P = 0.007 and P = 0.02, respectively). CONCLUSIONS We suggest that surgical treatment of flail chest and multiple rib fractures has clinical benefit and improves respiratory parameters even in the presence of multiple trauma injuries.

The Ponseti method for treating idiopathic clubfoot is based on gradual manipulations and corrective plaster castings followed by a years-long period of use of a foot orthosis. The role of surgery is limited. The factors that may affect outcome and their influence are subject of controversy. The aim of the study is to systematically and objectively evaluate the results of Ponseti treatment in our region of Southern Israel and focus on the role of the Achilles tenotomy and compliance to foot orthosis as factors that may influence outcome. The use of Ponseti method was retrospectively studied (level of evidence IV) by searching computerized medical files and clinical photos. The severity of deformity was evaluated by Dimeglio score (D-score) at baseline and at last examination. During 2006-2014, 57 children with idiopathic clubfoot (total 90 feet) were enrolled. An Achilles tenotomy was performed in 55/90 (61.1%) of the feet. If the D-score was 15 or higher there was a 20% increase in the incidence of Achilles tenotomy. The parental compliance had a weak protective effect against relapse. The treatment of idiopathic clubfoot by the Ponseti method was successful and reliable, proving efficiency and universality of the method. A dominant predictor for relapse was not seen. An incidental observation was that extended time in cast may buffer the adverse effects of low compliance rate. Although the initial severity, or compliance to braces are important, there may be other factors that affect the outcome such as, accuracy of the casting technique, time in the cast, access to a dedicated clubfoot clinic, cooperation with nurses and pediatricians, economic status that allows purchase of new generation of braces, cultural perception, and education level of the patient population are some examples.

BACKGROUND CONTEXT Cervical disc replacement today is a very viable option in the management of degenerative disc disease. This 5-year prospective randomised controlled trial compared the combined (single & multilevel), clinical outcomes between NunecTM and Prestige. PURPOSE Our study hypothesis was that the clinical outcomes following anterior cervical decompression disc replacement using NunecTM (PEEK on PEEK) prosthesis is better than or same as Prestige (METAL on METAL) replacement at short to long term follow-up (6 months, 1, 2, 3, 4, and 5 years) STUDY DESIGN/SETTING Prospective Randomised Controlled Trial. PATIENT SAMPLE A total of 57 participants (NunecTM 28; Prestige® 29) were recruited after screening through a rigorous inclusion and exclusion criteriae. OUTCOME MEASURES Primary Outcome measures included (1) Visual Analogue score for Neck pain (VAS-NP) (2) Visual Analogue score for Arm pain (VAS-AP) (3) Neck Disability Index (NDI) (4) Depression and (5) Anxiety scores. Secondary outcome measures as evaluated in the follow-up clinics, included (1) return to work (2) clinical range of movement (3) adjacent segment re-operation (4) complications and (5) implant failure. METHODS Paired t-test was used to analyse any statistical difference between pre and postoperative scores and an unpaired t-test was used to compare the outcome scores between NunecTM and Prestige. RESULTS The mean duration of symptoms for NunecTM was 44.0 months (0–204; SD=52.1) and for Prestige 43.8 months (0–350; SD=78.3). The mean follow-up for NunecTM was 4.86years (2–6 years; SD=0.89) and for Prestige 4.52years (1–6 years; SD=1.18).Apart from NDI for NunecTM, comparison between pre and post-op outcome scores showed a statistically significant improvement (p .05). VAS-NP: CI=−2.27 to 1.27, P=.5733; VAS-AP: CI=−2.46 to 1.50, P=.6303; NDI: CI=−2.55 to 22.2, P=.1170; Anxiety: CI=−2.15 to 3.00, P=.7399; Depression: CI=−2.10 to 3.18, P=.6826. CONCLUSIONS This study validates our hypothesis that the clinical outcomes following anterior cervical decompression disc replacement using NunecTM is the same as Prestige (METAL on METAL) replacement at short to long-term follow-up. There is no tangible advantage in the choice between these two devices. However, there is a statistically significant improvement between the pre and postoperative clinical outcomes for both the devices

Object Modic changes (MCs) and high-intensity zones (HIZs) potentially serve as variably sensitive markers for discogenic chronic low-back pain (CLBP). No study has hitherto assessed the phenomenon of MC-HIZ coexistence at a single level, and the goal in this study was to assess the nature and frequency of this phenomenon. Methods One hundred twenty consecutive patients with discogenic CLBP in whom lumbar MR imaging studies had demonstrated an HIZ, an MC, or both were included. Results This cohort (120 consecutive patients with 193 degenerative discs) had discogenic CLBP in at least 1 lumbar level associated with either an HIZ (77 discs), an MC (67 discs), or both (16 patients); there were 55 coexistent non-HIZ/non-MC degenerative discs. Painful MC-HIZ coexistence at 1 level occurred in 6 patients (5 of whom were female). If HIZs and MCs were random, independent entities, then MC-HIZ coexistence at 1 level would have been expected in 67 × 77/193 (that is, 27) discs. The observed frequency was therefore significantly lower (χ2 = 41, p < 0.001). There were no significant demographic differences between groups. The HIZ disc height (8 ± 0.2 mm) was significantly greater than the MC (6.6 ± 0.2 mm) or MC-HIZ (6.7 ± 0.2 mm) disc heights (p < 0.001). Conclusions In patients with discogenic CLBP associated with HIZ or MC lesions, MC-HIZ coexistence at 1 level was significantly rarer than expected even by chance; thus, despite both being manifestations of a seemingly common degenerative process, HIZ and MC more closely represent “either/or” phenomena. Because HIZ disc height was significantly greater, HIZs may develop earlier in the disc degenerative ontogeny. If any degenerative disc may only display an HIZ first, yet may ultimately display an MC instead, then HIZs must invariably regress as MCs supervene (or even vice versa). The MC-HIZ coexistence would therefore represent either a rare stable state (possibly more common in females) or a transitory state, as one lesion gradually replaces the other. Longitudinal studies would confirm or refute these hypotheses, although significantly larger sample sizes would be required.

Study Design. Technical report. Objective. To minimize the gross artefact associated with a conventional metallic lumbar total disc arthroplasty (TDA) device on a conventional high field-strength (1.5 Tesla [T]) magnetic resonance imaging (MRI) scanner. Summary of Background Data. Gross artefact is often apparent with ferromagnetic metallic TDA devices on conventional high field-strength MRI scanners. Such artefact completely obliterates MRI assessment at the operated level, and usually obscures visualization of adjacent segments. Because adjacent segment preservation is a raison d'etre of spinal TDA, clarity of imaging at this latter level is imperative. A failure to image adjacent segments may presage investigations, which are either invasive (e.g., myelography) or associated with significant radiation hazard (e.g., computed tomography), both with significantly less diagnostic sensitivity. This could negatively direct TDA choice with certain TDAs. Methods. Progressive modifications to specific imaging parameter settings were sought on a conventional high field-strength (1.5T) closed-bore scanner to match the minimal artefact previously observed on a lower field-strength (0.3T) open scanner. Direct comparisons were made between each modified protocol image obtained initially using a phantom; however, routine postoperative MRIs were subsequently obtained in n = 40 patients following lumbar TDA insertion. Results. Key parameter modifications were required in the receive bandwidth, the strength of the frequency encoding gradient, as well as in the echo train length. The use of higher specification "focused gradients" was also avoided. The overall effect was to reduce the slew rate of the gradients, which limited artefact due to a decrease in phase dispersion. Such appearances effectively matched with those previously obtained on the low field-strength (0.3T) open scanner in n = 40 patients. Conclusion. Relatively simple modifications to MRI parameter settings can be made on conventional high field-strength (1.5T) closed-bore scanners, which minimize metal artefact and enhance imaging of adjacent segments with ferromagnetic TDA devices. Such modifications effectively match appearances to those obtained with outmoded low field-strength (0.3T) open-bore scanners.

Various ball and socket-type designs of cervical artificial discs are in use or under investigation. Many artificial disc designs claim to restore the normal kinematics of the cervical spine. What differentiates one type of design from another design is currently not well understood. In this study, authors examined various clinically relevant parameters using a finite element model of C3–C7 cervical spine to study the effects of variations of ball and socket disc designs. Four variations of ball and socket-type artificial disc were placed at the C5–C6 level in an experimentally validated finite element model. Biomechanical effects of the shape (oval vs. spherical ball) and location (inferior vs. superior ball) were studied in detail. Range of motion, facet loading, implant stresses and capsule ligament strains were computed to investigate the influence of disc designs on resulting biomechanics. Motions at the implant level tended to increase following disc replacement. No major kinematic differences were observed among the disc designs tested. However, implant stresses were substantially higher in the spherical designs when compared to the oval designs. For both spherical and oval designs, the facet loads were lower for the designs with an inferior ball component. The capsule ligament strains were lower for the oval design with an inferior ball component. Overall, the oval design with an inferior ball component, produced motion, facet loads, implant stresses and capsule ligament strains closest to the intact spine, which may be key to long-term implant survival.

Background The A-Mav (Medtronic, Sofamor Danek, Memphis, TN) is a well-established lumbar total disc arthroplasty device. The O-Mav (Medtronic) is a more recent innovation designed to minimize the potential vascular complications associated with A-Mav insertion at L4/5. No study has hitherto studied the relative accuracy or safety of the two techniques. Purpose To compare the accuracy of lumbar disc arthroplasty placement by using the anterior technique (A-Mav) with the oblique (O-Mav) technique. Study design Technical report. Patient sample Fourteen patients. Outcome measures Implant placement accuracy on high-resolution computed tomography scan. Comparative morbidity, mortality, blood loss, and operating time were also assessed. Methods Patients were considered for lumbar disc arthroplasty who had suffered chronic discogenic low back pain unresponsive to nonoperative management for at least 6 months. All patients were operated on at the L4/5 level. A-Mavs were inserted in 7 patients and O-Mavs in 7. Implant placement was analyzed postoperatively by using computer software on high-resolution computed tomography scan with respect to four parameters: (1) off-center malplacement, (2) axial rotational malplacement, (3) coronal tilt, and (4) vertebral body susbsidence. Comparative morbidity, mortality, blood loss, and operating time were also assessed. Results Subsidence, off-center malplacement, and rotational malplacement were significantly increased in O-Mavs compared with A-Mavs (4.3±0.6 mm vs. 1.6±0.6 mm, p=.008; 3.1±0.4 mm vs. 1.3±0.4 mm, p=.006; 6.5°±1.2° vs. 3.8°±0.4°, p=.046). No significant differences were found between O-Mavs and A-Mavs in tilt, operating time, blood loss, or morbidity and mortality. Conclusions O-Mav insertion appears to be complicated by significantly greater vertebral body subsidence and malplacement than A-Mav insertion. A-Mav insertion therefore appears to be more accurate and less complicated yet equally as safe as O-Mav insertion.

Background Anterior lumbar disc replacements are used to restore spinal alignment and kinematics of a degenerated segment. Compared to fusion of the segment, disc replacements may prevent adjacent segment degeneration. To resolve some of the deficiencies of anterior lumbar arthroplasty, such as the approach itself, difficulty of revision, and postoperative facet pain, 360° motion preservation systems based on posterior disc and posterior dynamic system (PDS) designs are being pursued. These systems are easier to revise and address all the pain generators in a motion segment, including the nerves, facets, and disc. However, biomechanics of the 360° posterior motion preservation system, including the contributions of the 2 subsystems (disc and PDS), are sparsely reported in the literature.nds. Methods An experimentally validated 3-dimensional finite element model of the ligamentous L3-S1 segment was used to investigate the differences in biomechanical behavior of the lumbar spine. A single-level 360° posterior motion preservation system and its individual components in various orientations were simulated and compared with an intact model. Appropriate posterior surgical procedures were simulated. The PDS, a curved device with male and female components, was attached to the pedicle screws. The finite element models were subjected to 400 N of follower load plus 10Nm moment in extension and flexion. Results The PDS restored flexion/extension motion to normal. The artificial disc led to increases in range of motion (ROM) compared with the intact model. ROM for the 360° system at the implanted and adjacent levels were similar to those of the respective intact levels. ROM was similar whether the discs were placed (a) both parallel to the midsagittal plane, (b) both angled 20° to the midsagittal plane, and (c) one at 20° and one parallel to the midsagittal plane. However, the stresses were slightly higher in the nonparallel disc configuration than in the parallel disc configuration, both in flexion and extension modes. Conclusions Posterior disc replacement with PDS restored the kinematics of the spine at all levels to near normal. In addition, placing the discs in a nonparallel configuration with respect to the midsagittal plane does not affect the functionality of the discs compared with parallel placement. Posterior disc replacement alone is not sufficient to restore the segment biomechanics to normal levels. Clinical Relevance Finite element analysis results show that, unlike implants for fusion, PDS and posterior discs together (360° motion preservation system) are needed to preserve ROM. Such systems will prevent adjacent level degeneration and address pain from various spinal components, including facets.

✓Modic Type 2 (MT2) neuroimaging changes are considered stable or invariant over time and relatively quiescent, whereas Modic Type 1 (MT1) changes are considered unstable and more symptomatic. The authors report two cases in which MT2 changes were symptomatic and evidently unstable, and in which chronic low-back pain severity remained unaltered despite a MT2–MT1 reverse transformation. Two women (41 and 48 years old) both presented with chronic low-back pain. Magnetic resonance (MR) images demonstrated degenerating discs at L5–S1 associated with well-established MT2 changes in adjacent vertebrae. Repeated MR imaging in these two patients after 11 months and 7 years, respectively, revealed reverse transformation of the MT2 changes into more florid MT1 changes, despite unaltered chronic low-back pain severity. Following anterior discectomy and disc arthroplasty, immediate abolition of chronic low-back pain was achieved in both patients and sustained at 3-year follow up. Modic Type 2 changes are therefore neither as stable nor as quiescent as originally believed. Each type can change, with equal symptom-generating capacity. More representative imaging–pathological correlates are required to determine the precise nature of MT changes.

The aim of this study was to determine whether obesity affects pain, surgical and functional outcomes following lumbar spinal fusion for low back pain (LBP). A systematic literature review and meta-analysis was made of those studies that compared the outcome of lumbar spinal fusion for LBP in obese and non-obese patients. A total of 17 studies were included in the meta-analysis. There was no difference in the pain and functional outcomes. Lumbar spinal fusion in the obese patient resulted in a statistically significantly greater intra-operative blood loss (weighted mean difference: 54.04 ml; 95% confidence interval (CI) 15.08 to 93.00; n = 112; p = 0.007) more complications (odds ratio: 1.91; 95% CI 1.68 to 2.18; n = 43858; p < 0.001) and longer duration of surgery (25.75 mins; 95% CI 15.61 to 35.90; n = 258; p < 0.001). Obese patients have greater intra-operative blood loss, more complications and longer duration of surgery but pain and functional outcome are similar to non-obese patients. Based on these results, obesity is not a contraindication to lumbar spinal fusion. Cite this article: Bone Joint J 2015;97-B:1395–1404.

Disc prosthesis is the new treatment for degenerative disc disease in the lumbar spine. Key to assessing the interest in this new motion technique is evaluating the results in terms of functional and radiologic outcomes. This prospective study reports the outcome of 64 Maverick devices implanted between January 2002 and November 2003. The degree of improvement was equivalent to that obtained with anterior fusion cages using the mini-invasive technique. Radiographic follow-up in this series showed a degree of mobility close to normal. The technique is safe because the intra- and postoperative complication rate is low. The Oswestry score improved for 75% of patients. This improvement is significantly correlated with facet arthrosis and muscle fatty degeneration.

A prospective radiographic study of the influence of total disc replacement on spinal sagittal balance. The goal of this study was to prospectively determine the effect of a single-level, total disc replacement on the sagittal balance of the spine, especially on sacral tilt (ST), pelvic tilt (PT), and lumbar lordosis. It has been shown that lumbar fusion may deleteriously alter the sagittal balance of the spine, including a decrease in the ST and lumbar lordosis. Clinically, postfusion pain has been shown to be significantly related to a decreased ST, increased PT, and decreased lumbar lordosis, independent of other factors such as pseudoarthrosis. To our knowledge, the influence of total disc replacement on spinal sagittal balance has not yet been reported in the literature. This is a prospective study of 35 patients who received a single level disc replacement using the Maverick Total Disc Arthroplasty system (Medtronic Sofamor Danek, Memphis, Tennessee) by a single surgeon at one institution from March 2002 to September 2003. The preoperative and postoperative radiographic evaluation included standing anteroposterior and lateral full spine films that included the femoral heads. The parameters studied were ST, PT, global and segmental lordosis, and global kyphosis. The average age of the 35 patients studied was 44.3 years (range 35-57). There were 18 females and 17 males. The disc arthroplasty was performed at the L4-L5 level in 19 patients and at the L5-S1 level in 16 patients. The average follow-up was 14 months (range 6-22 months). The preoperative values of global lordosis, ST, and PT were 51.5 degrees , 37.8 degrees , 16.9 degrees and, at last follow-up, they were 51.4 degrees , 37.4 degrees , and 17.5 degrees , respectively. These changes were not significantly different. When the groups were separated according to the level operated, there was still no statistical difference with regard to the overall lordosis, ST, PT or kyphosis from pre- to postoperative period or when the two groups were compared with each other. The level above the prosthesis has always significantly less lordosis. In the present study with use of a motion-preserving Maverick prosthesis, it appears that the patient is able to maintain the preoperative sagittal balance. The prosthesis has enough freedom of motion to allow the patient to maintain the natural sagittal and spinopelvic balance needed to prevent potential undue stress on the muscles and the sacroiliac joint. Although the number of patients is small, this is the first study to our knowledge that evaluates the sagittal balance after motion-preserving total disc arthroplasty.

Lumbar disc prostheses have been used in treating symptomatic degenerative disc diseases. A few prostheses of the ball-socket design are currently available for clinical use, the joint mechanism being materialized either with a hard polymer core or a metal-to-metal couple. Other prostheses of "shock absorber" design were not available at the time of the study. The objective of this work was to establish whether there was a difference in the shock absorption capacity between a device having an ultra-high-molecular-weight polyethylene center core and a device having a metal-on-metal bearing. Vibration and shock loading were applied to two lumbar total disc prostheses: PRODISC, manufactured by Spine Solutions, and MAVERICK Total Disc Replacement, manufactured by Medtronic Sofamor Danek. The shock absorption capacity of the device was evaluated by comparing the input and the output force measurements. The disc prosthesis was mounted onto a test apparatus. Each side of the device was equipped with a force sensor. The input shock load and the output resulting forces were simultaneously measured and recorded. The loading force pattern included 1). a static preload of 350 N plus an oscillating vibration of 100 N with frequency sweeping from 0 to 100 Hz and 2). a sudden shock load of 250 N applied over a 0.1-second interval. Both input and output signal data were processed and were transformed into their frequency spectrums. The vibration and shock transmissibility of the device, defined as the ratio of the output spectrum over the input spectrum, were calculated in sweeping the frequency from 0 to 100 Hz. The phase deviation was calculated to characterize the shock absorber effects. For both tested devices under vibration and shock loading, the phase angle displacement between the input and the output signals was 10 degrees. Under oscillating vibration loading, both tested devices had a transmission ratio higher than 99.8%. Over the frequency interval 1-100 Hz, the difference in transmission ratio between the two devices was

It is a general principle with arthroplasty insertion that precise implant centering is critical for long term function and outcome. Whilst some authors have proclaimed that lumbar total disc arthroplasty (TDA) may be different, and that off -centre placement may be functionally well tolerated, these claims are premature: significantly worse clinical results have already been reported with poorly placed TDA at 2 years. Accurate TDA placement requires a precise and consistent definition of the desired coronal midline target (which is currently lacking), as well as a procedural mechanism to optimize placement at that target. We summarize our experience, as well as others', in achieving these two requirements. Long-term outcomes after lumbar TDA insertion should only be compared with results from fusion where TDAs have been implanted accurately.

STUDY DESIGN Original study. OBJECTIVE To compare the accuracy of radiograph (XR) estimates of lumbar total disc arthroplasty placement with high-resolution computed tomography (CT). SUMMARY OF BACKGROUND DATA Most lumbar disc arthroplasties are inserted and subsequently analyzed using anteroposterior and lateral XR: XR estimates are often correlated with clinical outcomes. No study has hitherto assessed the relative accuracy of XR estimates with CT. METHODS Patients (N = 36) had recently undergone uncomplicated lumbar total disc arthroplasty for unresponsive discogenic back pain. Interpedicular midline malplacement and vertebral body penetration (VBP) were estimated after surgery, by "blinded" independent review, using computer software on both nonrotated XR and high-resolution CT at the same clinic attendance. RESULTS Results were obtained in N = 36 patients. No significant differences were found between XR and CT in the mean +/- standard error estimation of either midline malplacement (1.7 +/- 0.2 mm vs. 1.8 +/- 0.2 mm, P = 0.86) or VBP (1.5 +/- 0.3 mm vs. 1.6 +/- 0.3 mm, P = 0.79). However, the correlation between XR and CT for midline malplacement appeared strong (r = 0.72, P 0.10). The standard deviation of XR-CT differences for VBP (2.2 mm) was almost twice that for midline malplacement (1.2 mm). XR-CT differences exceeded the 95% limit of agreement in 6% of midline placement estimates, and in 8% for VBP. CONCLUSION Nonrotated XR permitted an accurate and valid estimate of midline malplacement relative to CT in most cases. However, the correlation was biased toward XR underestimation of CT-derived malplacement, and highly significant XR-CT differences occurred in 6% of estimates: early postoperative CT is therefore recommended to enhance the estimation of midline placement. XR-CT agreement for VBP was poor: CT is therefore indicated in all cases for this parameter. This is the first study to compare the accuracy of XR in estimating lumbar total disc arthroplasty placement with CT.

STUDY DESIGN: Technical report. OBJECTIVE: To compare the accuracy of lumbar total disc arthroplasty placement using an image-guidance system (IGS) with conventional fluoroscopy. SUMMARY OF BACKGROUND DATA: Most disc arthroplasties are inserted and analyzed using fluoroscopy. One previous cadaveric study demonstrated beneficial, but insignificant, effects of IGS on total disc arthroplasty placement compared with conventional fluoroscopy. METHODS: Patients were considered for lumbar total disc arthroplasty who had chronic discogenic low back pain unresponsive to nonoperative management for at least 6 months. Total disc arthroplasty was performed in n = 6 with IGS and in n = 14 without IGS. Implant placement was analyzed after surgery using computer software on high-resolution CT with respect to 3 parameters: 1) off-center mal-placement, 2) axial rotational mal-placement, and 3) coronal tilt. RESULTS: Arthroplasties inserted with IGS were positioned with significantly greater accuracy than non-IGS arthroplasties with respect to all 3 parameters measured (off-center: 1.1 +/- 0.3 vs. 2.3 +/- 0.3 mm, P = 0.031; rotation: 88.8 degrees +/- 0.2 degrees vs. 87.1 degrees +/- 0.4 degrees; P = 0.0084; and tilt: 1.0 degrees +/- 0.5 degrees vs. 2.6 degrees +/- 0.3 degrees, P = 0.01). There was no significant difference in operating time between non-IGS controls (123 +/- 5 minutes) and IGS (139 +/- 10 minutes) groups (P = 0.129). CONCLUSION: This is the first clinical study to demonstrate significantly improved accuracy of lumbar total disc arthroplasty placement on CT using IGS compared with conventional fluoroscopy. IGS should be considered for routine use with lumbar total disc arthroplasty insertion.

Introduction Patients with lumbar spinal stenosis who do not respond satisfactorily to nonoperative measures may require decompression. Laminectomies/decompression without instrumentation may cause instability and associated symptoms. Fusion often involves multiple segments potentially increasing the risk of proximal junctional kyphosis (PJK), adjacent segment disease (ASD), and surgical morbidity of lateral exposure to prepare fusion bed. We have therefore been using the TRANSITION Stabilization System (Globus Medical, Inc., Audubon, Pennsylvania, United States) to provide stability without fusion at the operated levels. Following insertion of pedicle screws, to which the rod is attached, a semirigid rod is custom built along a central cord using a combination of rigid screw head attachments, flexible spacers, and a compressible bumper. Biomechanical studies have indicated superior performance to other similar systems. We report our clinical results. Patients and Methods A retrospective analysis of prospectively collected data was performed for patients who underwent surgery between September 2011 and December 2013. Outcome measures included Oswestry Disability Index (ODI), Visual Analog Scale (VAS) back/leg pain, Hospital Anxiety and Depression Scale, and complications. Statistical analysis was performed with paired and unpaired tests. Results Demographics: Data were available for 24 patients; 8 females and 16 males. Mean age at surgery was 66.8 years. Mean body mass index was 30.4 kg/m2. Mean length of follow-up was 44 (range, 10–109) weeks. Mean postoperative length of stay was 7.2 days, and when those patients requiring reoperation for complications were excluded it was 4.4 days. Surgery: A total of 10 L3–S1, 4 L4–S1, 1 L4–L5, 3 L2–L5, 4 L3–L5, 1 L1–L5, and 1 L2–S1 stabilizations were performed with a variety of combined central and foraminal decompressions. Mean blood loss was 648 mL and surgical time 176 minutes. Eight patients sustained intraoperative dural tears that were sealed with fibrin sealant. Outcomes: Mean ODI improved from 45.1 to 31.3 ( p = 0.001), VAS back from 6.7 to 3.7 ( p ≤ 0.01), VAS legs from 6.7 to 2 ( p ≤ 0.01), anxiety from 6.1 to 5.4 ( p = 0.37), and depression from 7.3 to 3.7 ( p = 0.033). There was no statistical correlation between pre- and postoperative ODI, VAS back or legs, depression/anxiety scores, and demographics. Reoperations: There were three early reoperations: one patient for discharging wound with positive microbiology and for revision of a screw, one patient for discharging wound with negative microbiology, and one patient for revision of a screw. There were no implant failures or revisions for PJK or ASD to date. Conclusion Our results using the TRANSITION Stabilization System suggests that pedicle-based semirigid posterior stabilization systems warrant further consideration as a potential tool in providing satisfactory early postoperative results while potentially reducing the long-term morbidity associated with fusions for lumbar stenosis. We would encourage further research to assess longer term results and radiographic outcomes.

Introduction Motion preservation with cervical disc arthroplasty (CDA) implants has consistently been shown, in numerous randomized controlled trials, to produce equivalent or superior clinical outcomes to anterior cervical decompression and fusion. There has therefore been a call to compare outcomes between different arthroplasty implants. We report the clinical outcomes, at 2-years follow-up, of a randomized controlled trial comparing two fundamentally different implants—the NUNEC Cervical Arthroplasty System (RTI Surgical, Inc., Florida, United States), is a PEEK on PEEK articulating device with inferior ball and superior trough secured by cam lock screws and the PRESTIGE LP Cervical Disc System (Medtronic, Minnesota, United States), is a titanium ceramic composite articulating device with superior ball and inferior trough secured by keels. Material and Methods A review of 52 patients with symptomatic degenerative disc disease causing cervical radiculopathy and/or myelopathy enrolled in this United Kingdom National Health Service (NHS) Research Ethics Committee approved study has been performed. Preoperatively patients were randomized into the two treatment groups (surgery with NUNEC Cervical Arthroplasty System or PRESTIGE LP Cervical Disc System) and blinded until after surgery. All procedures were performed by or under direct supervision of two senior surgeons at the host institution. Patient reported outcome measures (neck disability index (NDI), visual analogue scale (VAS) for arm and neck pain and hospital anxiety and depression scale) were collected preoperatively and at follow-up. Surgical time, blood loss, and complications have also been reviewed. Outcomes have been compared between groups. Results Data for 47 patients is reported (1 withdrawal due to relocation, 4 nonattendance at follow-up excluded). There were 51 NUNEC implants used (3 one level, 12 two level, 4 three level, and 3 four level) and 52 PRESTIGE LP implants used (6 one level, 12 two level, 6 three level, and 1 four level). There was no statistically significant difference in the distribution of the number of operated levels between the two implant groups and therefore analysis of data has been performed using the means for each group. There was no statistically significant difference in the preoperative outcome scores or demographics between the groups. In the NUNEC group NDI improved from 49 to 45.6, VAS neck from 7.5 to 4.7, VAS arms from 7.2 to 4, depression from 8.5 to 8.3, and anxiety from 9.2 to 8.6. In the PRESTIGE LP group NDI improved from 56 to 44, VAS neck from 7.2 to 4.5, VAS arms from 6.4 to 4.5, depression from 9.1 to 8, and anxiety from 9.5 to 9.2. There was no statistically significant difference in the postoperative outcomes between the groups. There were no reoperations in either group for ASD. Conclusion There has been a call for studies comparing different CDA implants. We report the outcomes at 2 years of a randomized controlled trial comparing the NUNEC cervical arthroplasty system and the PRESTIGE LP cervical disc system. No statistically significant difference was found in outcome measures between the two implants. Further analysis is ongoing to compare the radiological outcomes, which may reflect longer term results.

Introduction Cervical myelopathy secondary to cord compression may require surgical decompression with the aim of surgery being to arrest the progression of myelopathy and associated symptoms. Theoretical concerns have been raised regarding the use of cervical disc arthroplasty (CDA) in patients with myelopathy due to the fear that continued motion may cause continuing microtrauma to the cord. As such there is a paucity of reported data. We report the clinical results of anterior cervical decompression and CDA in patients with cervical myelopathy at our institution. Patients and Methods Patients who had undergone one- or two-level anterior cervical decompression and CDA for myelopathy were identified from the authors' institution's database. Prospectively collected data including neck disability index (NDI), visual analogue scale (VAS) for neck and arm pain, patient reported activity level, and hospital anxiety and depression scale were reviewed. Statistical analysis was performed for significance. Results Demographics: 40 patients. Mean age at surgery 51.3 years (range, 35–75). Operated levels, 63: 17 one- and 23 two-level procedures. Seven patients had cord compression at both levels; 21 had myelomalacia at one level and 3 at two levels. The average duration of preoperative symptoms was 37.5 months. Mean follow-up was 3.2 years (range, 1–7.4 years). Surgery: Surgery was performed using four different implants; 28 PRESTIGE LP Cervical Disc System (Medtronic, Minnesota, United States), 24 NUNEC Cervical Arthroplasty System (RTI Surgical, Inc., Florida, United States), 10 Discocerv (Scient́x-Alphatec Spine, France), and one DISCOVER Cervical Arthroplasty Disc Replacement System (DePuy Spine, Inc., Massachusetts, United States). Overall, 34 procedures were performed at C5/6, 21 at C6/7, 7 at C4/5, and 1 at C3/4. Outcomes: Mean NDI improved from 47.7 to 33.96 ( p Conclusion We report the clinical results of anterior cervical decompression and CDA in 40 patients with cervical myelopathy, with follow-up up to 7.4 years. Statistically significant improvements were seen in NDI and VAS scores. The level of improvement or maintenance of activity level is likely a reflection of a general patient reported activity measure being used rather than a specific myelopathy scale. We believe our results support further investigation of CDA in myelopathy.

Introduction Motion preservation with cervical disc arthroplasty implants has consistently been shown, in numerous randomized controlled trials, to produce equivalent or superior clinical outcomes to anterior cervical decompression and fusion. Therefore, there has been a call, within the spinal surgery community, to compare outcomes between arthroplasty implants. Although it is important to evaluate positive outcomes, it is also of vital importance to analyze complications and assess the potential influence of different implant designs on complications. We have experience in a large series of using several different arthroplasty implants. We have reviewed our series and have identified implants that have subsided. We provide a commentary on these cases. Material and Methods A retrospective review of all single-level anterior cervical decompression and disc arthroplasty cases, performed at the authors' institution, between 2006 and 2012 was conducted. Postoperative X-rays were assessed for any degree of subsidence compared with immediate postoperative X-rays. Cases with evidence of subsidence were studied for potential implicated factors. Results A total of 157 cases were reviewed consisting 64 PRESTIGE LP Cervical Disc System (Medtronic, Minnesota, United States), 51 NUNEC Cervical Arthroplasty System (RTI Surgical, Inc., United States), 35 Discocerv (Scient'x-Alphatec Spine, Arras, France), and 7 other implants in small numbers. Overall, 11 (7%) cases showed evidence of implant subsidence—two (3%) PRESTIGE LP, five (10%) NUNEC, and four (11%) Discocerv. In the cases that subsided, there were three males and eight females. There was a following variety of location of subsidence: anterior, posterior and complete surface of the implant, superior, and inferior. Seven of the cases did not fully cover the disc space in the anteroposterior plane. Three cases appeared to have been impacted into osteophytes posteriorly but subsidence was not necessarily in this location. The majority of cases appeared to have abnormal motion/spondylotic changes in adjacent levels, raising the possibility of abnormal forces being placed through the replaced level. Conclusion Cervical disc arthroplasty implant subsidence may be influenced by implant design, patient factors, and surgical technique. In this series, because of the small number of cases that showed subsidence, we cannot draw any firm conclusions. This report nevertheless should serve as an important stimulus for discussion and development regarding modifiable factors implicated in complications such as device subsidence.

STUDY DESIGN Prospective case series. OBJECTIVES To determine the safety and feasibility of routine preinjection of gelfoam embolization during percutaneous vertebroplasty. SUMMARY OF BACKGROUND DATA Percutaneous vertebroplasty has been used effectively in pain relief for vertebral fractures resulting from malignancy and osteoporosis. However, cement extrusion is a common problem and can lead to complications. Gelfoam embolization of venous channels before cement injection has not been widely used as a technique to prevent leakage. METHODS Thirty-one patients who met the inclusion-exclusion criteria for the study underwent percutaneous vertebroplasty. Venography was first performed to determine the flow pattern in the vertebrae and confirm needle placement. Next, routine gelfoam embolization of venous channels was performed. This was followed by low-pressure, minimal-volume cement injection. The outcome measure of cement leakage was assessed after surgery using radiographs and CT scans. RESULTS There were no complications. In the 31 patients, 61 levels of vertebroplasty were performed. Overall, there were 16 leaks out of 61 levels in 12 patients (26.2%). In osteoporotic fractures, there were 11 leaks in 49 levels, giving a leakage rate of 22.5%. There was only 1 epidural leak in this group (2%), and this was asymptomatic. Seven leakages were into the adjacent disc, 2 into the body, and 1 into the paravertebral tissues. In malignant fractures, there were 5 leakages out of 12 levels (41.7%). Of these, 2 were epidural leaks (16.7%), which were asymptomatic. CONCLUSIONS Complications resulting from leakage are the most feared side effect of the procedure. This has resulted in only limited application of vertebroplasty in the United Kingdom. Routine gelfoam embolization together with careful technique has been shown to be a safe and feasible method during vertebroplasty.

There has been little analysis assessing the correlation between the clinical functional result of total disc replacement and the arthrosis of the posterior facets or the fatty degeneration of the spinal muscles. However, such knowledge is essential for understanding the long-term outcome of devices in functional terms. This prospective study reports the outcome of 64 Maverick (Medtronic) devices implanted between January 2002 and November 2003.Oswestry score preoperatively and at 2-year follow-up was 43.8 and 23.1, respectively (P0.05). Low back pain improved from a mean Visual Analog Scale (VAS) score of 7.6 +/- 1.7 preoperatively to 3.2 +/- 1.8 at 2 years. Mean VAS leg pain score decreased from 3.9 to 2.1 at 2 years (P0.05). Facet osteoarthritis grade 1 or 2 did not influence outcome (P = 0.82). On the other hand, muscle degeneration of grades 1 and 2 led to a better outcome than grades 3 and 4 (P = 0.006).This is the first study showing that a semiconstrained implant with a fixed posterior center of rotation can be implanted with grade 1 and 2 facet arthrosis with a good clinical outcome. This seems to confirm previous work showing that a posterior center of rotation lightens the load on the facets. This is also the first study to show a relationship between muscle fatty degeneration and clinical results since the greater the amount of fat, the less satisfactory the result. These promising midterm results must be confirmed by further studies.

This paper reviews the design criteria, biomechanical and biological (wear and safety) testing of this chrome cobalt metal-on-metal, ball and socket design prosthesis. The surgical technique and early clinical results of the initial implantations are also reviewed. Initial results of 7 Maverick implantations showed all 7 patients attaining a 15 point Oswestry improvement within 3 months after implantation. This early result in a small sample is significantly quicker in recovery and improvement when compared to the historical control of the LT cage with Infuse IDE study. Longer term results and more careful study are needed of this interesting and optimistic finding.

The treatment of chronic low back pain due to advanced disk degeneration requires restabilization of the lumbar column, mainly by restoring disk function. Disk restabilization involves restoration and stabilization of the ligaments and annulus. Such restabilization represents a new concept [14, 29] in treating disk pathologies without the definitive loss of disk function [11, 13, 26]. Unlike fusion [20], the procedure is not definitive and makes it possible to restore function and mobility. Two prosthetic devices have now been on the market for about 10 years: the SB Charite [6, 8, 12, 15, 18, 27, 35], produced by Link, and the Prodisc [3, 30], manufactured by Spine Solution. This chapter looks at a new device, the Maverick disk prosthesis, which was developed according to biomechanical principles [21] and in the light of the biomechanical results obtained with the SB Charite and Prodisc. Preliminary results are promising.

Introduction Cervical fusion alters the biomechanics of the cervical spine. Adjacent levels compensate for motion lost at the fused levels. This may lead to or accelerate the development of symptomatic adjacent segment disease (ASD). Cervical disc arthroplasty (CDA) is a safe and effective alternative to fusion. It is postulated that by preserving motion at the operated level, the adjacent levels will be protected from ASD potentially related to fusion. ASD will develop over the long-term and therefore CDA implants must maintain motion and mimic the normal biomechanics of a native disc to have the protective effect. Implant design may influence a CDA implant's ability to do this. We aim to assess if the three implants with different designs do display different radiographic outcomes in vivo. Materials and Methods All one-level CDA patients with greater than 2-year radiographic follow-up were identified from hospital records. The C2 to C7 Cobb angle was measured on neutral lateral radiographs. The segmental Cobb angle was measured on lateral neutral, flexion, and extension radiographs with motion of the CDA calculated as the difference between the two later measurements. Any disc with < 2 degrees motion was identified as not exhibiting motion. Results A total of 55 patients were included. Average follow-up was 145 weeks. Three different implants were used—Discocerv (Scient’x-Alphatec Spine, France), NuNec (Pioneer Surgical Technology, United States) and PRESTIGE LP (Medtronic Ltd., United States). The most common operated level was C5/6 with 40 implants. Other levels consisted of one C3/4, four C4/5, and ten C6/7. The number of implants, cervical alignment, segment alignment, and segmental motion (in degrees) is shown in Table 1. There was no statistically significant difference in any outcome between the implants. One PRESTIGE LP required revision after 2 years. Bony fusion was observed in 12.5% of Discocerv, 14.3% of NuNec, and 12.1% of PRESTIGE LP. Twenty-five percent of Discocerv cases had some degree of subsidence, while this was seen in 7.1% of NuNec and 6.1% of PRESTIGE LP implants. Conclusion Our results indicate that CDA implant type influences the alignment of the replaced segment and preservation of motion. This may be due to the different biomechanical designs of the implants. While statistically significant differences were not observed, differences may be clinically significant. We acknowledge that limited conclusions can be drawn from our results due to differing group sizes, but our study serves as a basis and highlights the need for further in vivo and in vitro studies. Disclosure of Interest A. Berg: None declared J. Tankel: None declared C. Jensen: None declared A. Irwin: None declared B. Purushothaman: None declared G. Reddy: None declared T. Friesem: Conflict with RTI Surgical, Globus Medical

Introduction Foraminal and spinal canal stenosis causes neurogenic claudication. Interspinous devices provide an indirect decompression by distracting the involved vertebrae, thereby tightening the buckled flavum and opening the foramina and attempting to restore normal loading patterns in the lumbar spine which have altered due to disc degeneration. When used for indirect decompression alone, they avoid scar tissue formation in the canal. The DIAM (Medtronic, United States) is made of silicone and therefore conforms more to the interspinous space. The InSWing (Orthofix, United States) is made of PEEK (polyether ether ketone) and is noncompressible. We report the outcomes between these devices and between direct and indirect decompressions. Materials and Methods Retrospective analysis performed for surgery in July 2009 to 2011. Paired and unpaired t-test used to assess statistical significance ( p < 0.05). Results A total of 60 patients were included (22 females, 38 males), age 46 (21-78) years. Preoperative duration of symptoms was 65 (4-420) months. The numbers in each implant/decompression group and follow-up are shown in Table 1. Statistically significant improvement observed in all outcome measures in direct and InSWing groups and all outcomes except MCS in DIAM group. Indirect group improved in all outcomes, but these were significant only in VAS Back/Leg. InSWing and direct group scores improved more than the DIAM and indirect groups, respectively, but these differences were only significant in Oswestry in the decompression group. All five patients requiring revision surgery were in the DIAM group. Conclusion Statistically significant improvement was seen in all outcome measures in patients undergoing direct decompressions or implantation with InSWing implants. Improvement in scores was greater in these groups compared with the indirect decompression or DIAM groups. Disclosure of Interest A. Berg: None declared J. Tankel: None declared M. Hernandez: None declared C. Jensen: None declared B. Purushothaman: None declared G. Reddy: None declared T. Friesem: Conflict with RTI Surgical, Globus Medical

Introduction One surgical treatment modality for the management of degenerative disc disease causing back and/or leg pain is interbody fusion. Nonunion is associated with poor outcomes. The gold standard bone graft for augmenting and achieving fusion is iliac crest autograft but significant donor morbidity is associated with its harvest. Allografts require processing, to prevent transmission of infections, which impairs their osteogenic and osteoinductive properties. An alternative synthetic bone graft that avoids the morbidity of autograft is safe, and provides reliable fusion and is therefore desired. In our institution, we have used three synthetic bone grafts, Actifuse (Baxter, USA), i-FACTOR (Cerapedics, USA) and Vitoss BA (Stryker, USA), which all report to be bioactive and to enhance bone fusion in transforaminal lumbar interbody fusion (TLIF) procedures. They were all used in combination with morselized local autograft. Materials and Methods Patients undergoing TLIF surgery with one of the mentioned bone grafts were identified from hospital records. Postoperative radiographs were reviewed by an independent blinded radiologist for evidence of spanning trabeculae on orthogonal radiographs. Results A total of 40 patients (55 levels) were included. The number of patients, operated levels, follow-up, and cumulative and overall fusion rates for each bone graft group are demonstrated in Table 1. Conclusion Patients who underwent TLIF with a mixture of i-FACTOR combined morselized local autograft had a higher rate of fusion with a similar mean follow-up and higher cumulative fusion rates over the period studied than Actifuse and Vitoss BA. The smaller patient numbers in the Actifuse and Vitoss BA groups does limit comparisons. Disclosure of Interest None declared

Introduction Cervical fusion alters the biomechanics of the cervical spine with adjacent levels compensating for the lost motion. If multiple levels are fused, then the compensatory motion is even greater at the nonfused levels. This may be associated with the development of symptomatic adjacent segment disease. In addition, through motion preservation, postoperative morbidity associated with multilevel surgery is reduced—a single transverse anterior incision can be used, less pain is associated with posterior approach, and no collar or motion restrictions. Multilevel cervical disc arthroplasty is therefore an alternative to fusion to preserve motion and reduce the incidence of recurrence of symptomatic disease. Materials and Methods Lateral flexion and extension radiographs were analyzed for motion at the level of the disc arthroplasty using the posterior vertebral body angle. The difference between the posterior vertebral body angle in flexion and extension was taken. We classified any disc that had less than 2 degrees change in angle not to be exhibiting motion. Results Postoperative radiographs of 100 patients (59 two level, 34 three level, 7 four level) who had undergone anterior cervical decompression and cervical arthroplasty at two, three, or four levels with at least 1 year radiographic follow-up were reviewed. Radiographic data were available for 239 discs: 77% ( n = 185) of discs maintained motion of greater than 2 degrees. Average follow-up in this group was 94 (range, 52-291) weeks. In the group of 54 discs that exhibited less than 2 degrees, motion average follow-up was 110 (range, 54-291) weeks. In seven two-level constructs and in one three-level construct, all replaced levels showed less than 2 degrees of motion. Conclusion Multilevel cervical disc arthroplasty provides a viable option for maintaining motion at operated levels beyond 1 year and therefore may reduce the potential for symptomatic adjacent segment disease. Disclosure of Interest None declared