Cervical spine facet tropism (CFT) defined as the facets’ joints angles difference between right and left sides of more than 7 degrees. This study aims to investigate the relationship between cervical sagittal alignment parameters and cervical spine facets’ tropism. A retrospective cross-sectional study carried out in a tertiary center where cervical spine magnetic resonance imaging (MRI) radiographs of patients in orthopedics/spine clincs were included. They had no history of spine fractures. Images’ reports were reviewed to exclude those with tumors in the c-spine. A total of 96 patients was included with 63% of them were females. The mean of age was 45.53± 12.82. C2-C7 cobb's angle (CA) and C2-C7 sagittal vertical axis (SVA) means were −2.85±10.68 and 1.51± 0.79, respectively. Facet tropism was found in 98% of the sample in at least one level on either axial or sagittal plane. Axial C 2–3 CFT and sagittal C4-5 were correlated with CA (r=0.246, P 0.043, r= −278, P 0.022), respectively. In addition, C2-C7 sagittal vertical axis (SVA) was moderately correlated with axial c2-3 FT (r= −0.330, P 0.006) Also, several significant correlations were detected in our model Cervical vertebral slopes and CFT at the related level. Nonetheless, high BMI was associated with multi-level and multiplane CFT with higher odd's ratios at the lower levels. This study shows that CFT at higher levels is correlated with increasing CA and decreasing SVA and at lower levels with decreasing CA. Obesity is a risk factor for CFT

Cranio-cervical connection is a well-established biomechanical concept. However, literature of this connection and its impact on cervical alignment is scarce. Chin incidence (CI) is defined as a complementary to the angle between chin tilt (CHT) and C2 slope (C2S) axes. This study aims to investigate the relationship between cervical sagittal alignment parameters and CI with its derivatives. A retrospective cross-sectional study carried out in a tertiary center. CT-neck radiographs of non-orthopedics patients were included. They had no history of spine related symptoms or fractures in cranium or pelvis. Images’ reports were reviewed to exclude those with tumors in the c-spine or anterior triangle of the neck. A total of 80 patients was included with 54% of them were males. The mean of age was 30.96± 6.03. Models of predictability for c2-c7 cobb's angle (CA) and C2-C7 sagittal vertical axis (SVA) using C2S, CHT, and CI were significant and consistent r20.585 (f(df3,76) =35.65, P ≤0.0001, r=0.764), r20.474 (f(df2,77) =32.98, P ≤0.0001, r=-0.550), respectively. In addition, several positive significant correlations were detected in our model in relation to sagittal alignment parameters. Nonetheless, models of predictability for CA and SVA in relation to neck tilt (NT), T1 slope (T1S) and thoracic inlet axis (TIA) were less consistent and had a significant marginally weaker attributable effect on CA, however, no significant effect was found on SVA r20.406 (f(df1,78) =53.39, P ≤0.0001, r=0.620), r20.070 (f(df3,76) =1.904, P 0.19), respectively. Also, this study shows that obesity and aging are linked to decreased CI which will result in increasing SVA and ultimately decreasing CA. CI model has a more valid attributable effect on the sagittal alignment in comparison to TIA model. Future investigations factoring this parameter might enlighten its linkage to many cervical spine diseases or post-op complications (i.e., trismus)

Chordoma of the cervical spine is a rare but life-threatening disease with a relentless tendency towards local recurrence. Wide en bloc resection is recommended, but it is frequently not feasible in the cervical spine. Radiation therapy including high-energy particle therapy is commonly used as adjuvant therapy. The goal of this study was to examine treatment and outcome of patients with chordoma of the cervical spine. Patients affected by cervical spine chordoma who underwent surgery at the Rizzoli Institute and University Hospital of Modena, between 2007 and 2021 were identified. The clinical, pathologic, and radiographic data were reviewed in all cases. Patient outcomes including local recurrence and disease-specific survival (DSS) were analyzed using chi-square test and Kaplan-Meier survival analysis. Characteristics of the 29 patients (10 females; 19 males) included: median age at surgery 52.0 years (IQR 35.5 - 62.5 years), 10 (35%) involved upper cervical spine, 16 (55%) with tumors in the mid cervical spine, and 4 in the lower cervical spine (10%). Median tumor volume was 16 cm. 3. (IQR 8.7 - 20.8). Thirteen patients (45%) were previously treated surgically while 9 patients (31%) had previous radiation therapy. All patients underwent surgery: en bloc resection was passible in 4 patients (14 %), seventeen patients (59%) were treated with gross total resection while 8 patients (27%) underwent subtotal resection. Tumor volume was associated with a significantly higher risk of intraoperative complications (p < 0.01). Nineteen patients (65%) received adjuvant high-energy particle therapy. The median follow-up was 26 months (IQR 11 - 44). Twelve patients (41%) had local recurrence of disease. Patients treated with adjuvant high-energy particle therapy had a significant higher local control than patients who received photons or no adjuvant treatment (p = 0.01). Recurrence was the only factor significantly associated with worse DSS (p = 0.03 – OR 1.7), being the survival of the group of patients with recurrent disease 58.3% while the survival of the group of patients with no recurrent disease was 100%. Post-operative high-energy particle therapy improved local control in patients with cervical chordoma after surgical resection. Increased tumor volume was associated with increased risk of intraoperative complications. Recurrence of the disease was the only factor significantly associated with disease mortality

Using the transverse processes of fresh porcine lumbar spines as an experimental model we evaluated the heat generated by a rotating burr of a high-speed drill in cutting the bone. The temperature at the drilled site reached 174°C with a diamond burr and 77°C with a steel burr. With water irrigation at a flow rate of 540 ml/hr an effective reduction in the temperature was achieved whereas irrigation with water at 180 ml/hr was much less effective. There was a significant negative correlation between the thickness of the residual bone and the temperature measured at its undersurface adjacent to the drilling site (p < 0.001). Our data suggest that tissues neighbouring the drilled bone, especially nerve roots, can be damaged by the heat generated from the tip of a high-speed drill. Nerve-root palsy, one of the most common complications of cervical spinal surgery, may be caused by thermal damage to nerve roots arising in this manner

Surgical interventions for the treatment of chronic neck pain, which affects 330 million people globally [1], include fusion and cervical total disc replacement (CTDR). Most of the currently clinically available CTDRs designs include a metal-on-polymer (MoP) bearing. Numerous studies suggest that MoP CTDRs are associated with issues similar to those affecting other MoP joint replacement devices, including excessive wear and wear particle-related inflammation and osteolysis [2,3]. A device with a metal-on-metal (MoM) bearing has been investigated in the current study. Six MoM CTDRs made from high carbon cobalt-chromium (CoCr) were tested in a six-axis spine simulator, under standard ISO testing protocol (ISO-18192-1) for a duration of 4 million cycles (MC). Foetal bovine calf serum (25%v/v), used as a lubricant, was changed every 3.3×10. 5. cycles and saved for particle analysis. Components were taken down for measurements after each 10. 6. cycles; surface roughness, damage modes and gravimetric wear were assessed. The mean wear rate of the MoM CTDRs was 0.24mm. 3. /MC (SD=0.03), with the total volume of 0.98mm. 3. (SD=0.01) lost over the test duration. Throughout the test, the volumetric wear was linear; no significant bedding-in period was observed. The mean pre-test surface roughness decreased from 0.019μm (SD=0.005) to 0.012μm (SD=0.002) after 4MC of testing. Prior to testing, fine polishing marks on the bearing surfaces were observed using light microscopy. Following 4MC of testing, these polishing marks had been removed. Consistently across all components, surface discolouration and multidirectional, criss-crossing, circular wear tracks, caused by abrasive wear, were observed. The wear results showed low wear rates exhibited by MoM CTDRs (0.24mm. 3. /MC), when compared CTDR designs incorporating metal-on-polymer bearings (0.56mm. 3. /MC) [4] as well as MoM lumbar CTDRs [5,6] (0.76mm3/MC – 6.2mm. 3. /MC). These findings suggest that MoM CTDRs are more wear resistant than MoP CTDRs, however the particle characterisation and biological consequences of wear remain to be determined

Abstract. Objectives. While spinal fusion is known to be associated with adjacent disc degeneration, little is known on the role of the facet joints in the process, and whether their altered biomechanics following fusion plays a role in further spinal degeneration. This work aimed to develop a model and method to sequentially measure the effects of spinal fusion on lumbar facet joints through synchronisation of both motion analysis, pressure mapping and mechanical analysis. Methods. Parallel measurements of mature ovine lumbar facet joints (∼8yr old, n=3) were carried out using synchronised load and displacement measurements, motion capture during loading and pressure mapping of the joint spaces during loading. Functional units were prepared and cemented in PMMA endcaps. Displacement-controlled compression measurements were carried out using a materials testing machine (3365, Instron, USA) at 1 mm/min up to 950 N with the samples in a neutral position, while motion capture of the facet joints during compression was carried out using orthogonal HD webcams (Logitech, Switzerland) to measure the displacement of key facet joint features. The pressure mapping of load transfer during displacement was carried out using a flexible pressure sensor (6900 series, Tekscan, USA). Each sample was imaged at an isotropic resolution of 82 microns using a μCT scanner (XtremeCT, Scanco, Switzerland) to quantify the curvature within the facet joints. Results. Relative facet joint displacement under load, in a neutral position, showed more displacement (2.36 ±1.68 mm) compared to the cross-head when under compression (2.06 ±1.19 mm). Motion capture indicated the relative displacement of the facet joints was more posterior with some lateral motion. For five of the six facet joints, pressure measurement was possible only on 24±7 % of the surface due to the large change in curvature. Partially measured loads through the facets was 10.5 ±1.1 N. Conclusions. The relative displacement of the lumbar facet joints compared to the crosshead displacement was consistent with previous studies of cervical facet joints, despite the differences in anatomical geometry between cervical and lumbar joints. The difficulties in accurately measuring the load transfer through the facet joints was due to the age of the tissue and the degree of curvature of the facet joints. Synchronisation of the biomechanical data will provide a setup to assess the effect of interventions such as spinal fusion, with curvature-related issues unlikely to occur in human spines. Declaration of Interest. (a) fully declare any financial or other potential conflict of interest

Abstract. Objectives. There is still controversy in the literature over whether Cervical Foraminotomy or Anterior Cervical discectomy and fusion (ACDF) is best for treating cervical Radiculopathy. Numerous studies have focused on the respective complication rates of these procedures and outcome measures with a lack of due consideration to preoperative MRI findings. Proximal foraminal stenosis can theoretically be accessed via either approach. We aimed to investigate whether patient reported outcome measures (PROMs) favoured one approach over the other in patients with proximal foraminal stenosis. Methods. A single centre retrospective review of patients undergoing either ACDF or Cervical foraminotomy over the period 2012 to 2022. VAS, Neck disability index (NDI), EQ5DL and Patient Satisfaction on a Five Point Likert scale were obtained. Patients who had both an ACDF and a Foraminotomy were excluded. Axial MRI images were analysed and the location of the worst clinically relevant disc herniation stratified as follows: Central (1), Paracentral (2) and Foraminal (3). Correlations and average PROMs were analysed in SPSS. Results. PROMs scores were available for 33 ACDF patients and 37 Foraminotomy patients. Average surgery time in ACDF group was 167 minutes while Foraminotomy 142 minutes. Average Length of hospital stay was 6.24 days in the Foraminotomy group and 3.54 days in the ACDF group. 18 patients were excluded due to having both surgeries (2 of which developed CSF leaks postoperatively). Of the included patients there were no postoperative complications. 13 patients in the ACDF had Central or Paracentral stenosis in addition to proximal Foraminal stenosis, 3 patients in the Foraminotomy group had some significant Paracentral herniation just before the Proximal foramen. The majority of patients in both groups had pure proximal Foraminal stenosis (N= 17 (ACDF), 20 (Foraminotomy). The results showed no significant difference in PROMs between patients who received an ACDF or a Foraminotomy for Proximal foraminal stenosis (EQ5DL, NDI, and satisfaction, P= 0.268, 0.253 and 0.327). There was no correlation between location of the stenosis and PROM scores in either group. Conclusions. Our data suggest that Proximal foraminal stenosis can be effectively addressed by either an anterior ACDF or a Foraminotomy with no difference in complication rates. Foraminotomy has the benefit of no implant cost but longer hospital stay. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project

Aneurysmal bone cyst (ABC) of the spine is a locally aggressive benign lesion which can be treated by en bloc resection with wide margin to reduce the risk of local recurrence. To avoid morbidity associated with surgery, selective arterial embolization (SAE) can be considered the first-line treatment for ABCs of the spine. We previously introduced the use of autologous bone marrow concentrate (BMC) injection therapy to stimulate bone healing and regeneration in ABC of the spine. In this prospective study we described the clinical and radiological outcomes of percutaneous injection of autologous BMC in a series of patients affected by ABCs of the spine. Fourteen patients (6 male, 8 female) were treated between June 2014 and December 2019 with BMC injection for ABC of the spine. The mean age was 17.85 years. The mean follow up was 37.4 months (range 12–60 months). The dimension of the cyst and the degree of ossification were measured by Computed Tomography (CT) scans before the treatment and during follow-up visits. Six patients received a single dose of BMC, five patients received two doses and in three patients three doses of BMC were administered. The mean ossification of the cyst (expressed in Hounsfield units) increased statistically from 43.48±2.36 HU to 161.71±23.48 HU during follow-up time and the ossification was associated to an improvement of the clinical outcomes. The mean ossification over time was significantly higher in patients treated with a single injection compared to patients treated with multiple injections. No significant difference in ossification was found between cervical and non-cervical localization of the cyst. Moreover, the initial size of the cyst was not statistically associated with the degree of ossification during follow-up. The results of this study reinforce our previous evidence on the use of BMC as a valid alternative for spinal ABC management when SAE is contraindicated or ineffective. The initial size of the cyst and its localization does not influence the efficacy of the treatment. However, data suggest that BMC injection could be indicated as treatment of choice for spinal ABC in young adolescent women

Mental disorders in particular depression and anxiety have been reported to be prevalent among patients with spinal pathologies. Goal of the current study was to analyze the relationship of Zung pre- and post-op score to other PROs and length of stay. Secondary outcomes included revision surgery and post-operative infections. Data from the international multicenter prospective spine degenerative surgery data repository, DegenPRO v1.1 (AO Spine Knowledge Forum Degenerative) were utilized. Patients undergoing cervical or lumbar procedure were included. Patient's demographics, Charlson Comorbidity Index, surgical information, Zung score, NDI, pain related PROs and EQ-5D, and complications at surgery and at various post-op time periods. Except for hospital duration, data were analyzed, using multivariable mixed linear models. A robust linear regression model was used to assess the association between Zung score and hospital duration. All models were adjusted for gender and age. 42 patients had Zung score administered. Among those patients 22 (52%) were within normal range, 18 (43%) were mildly and 2 (5%) severely depressed. 62% of the patients had a lumbar pathology with fusion procedures being the most common. Median EQ-5D (3L) score at surgery was significantly higher (0.7, IQR: 0.4-0.7) for patients within normal range than for those with mild (0.4, IGR: 0.3-0.7) or severe depression (0.3, IQR: 0.3-0.3, p-value: 0.05). Compared to patients within normal Zung range, mixed models, indicated lower EQ-5D (3L) score values and higher values for neck and arm pain at surgery with both PROs and EQ-5D (3L) improving in patients with depression over the follow-up time. No association was found between Zung score and hospital length of stay. The initial analysis showed that 43% of the patients were mildly depressed and mainly male patients. Zung score was correlated with post-operative improvements in EQ-5D and arm and neck pain PROs

Bone turnover and microdamage are impacted by skeletal metastases which can contribute to increased fracture risk. Treatments for metastatic disease may further impact bone quality. This study aimed to establish an understanding of microdamage accumulation and load to failure in healthy and osteolytic vertebrae following cancer treatment (stereotactic body radiotherapy (SBRT), zoledronic acid (ZA), or docetaxel (DTX)). Forty-two 6-week old athymic female rats (Hsd:RH-Foxn1rnu, Envigo) were studied; 22 were inoculated with HeLa cervical cancer cells through intracardiac injection (day 0). Animals were randomly assigned to four groups: untreated (healthy=5, osteolytic=6), SBRT on day 14 (healthy=6, osteolytic=6), ZA on day 7 (healthy=4, osteolytic=5), and DTX on day 14 (healthy=5, osteolytic=5). Animals were euthanized on day 21. L1-L3 motion segments were compression loaded to failure and force-displacement data recorded. T13 vertebrae were stained with BaSO. 4. and µCT imaged (90kVp, 44uA, 4.9µm) to visualize microdamage location and volume. Damage volume fraction (DV/BV) was calculated as the ratio of BaSO. 4. to bone volume. Differences in mean load-to-failure were compared using three-way ANOVA (disease status, treatment, cells injected). Differences in mean DV/BV between treatment groups were compared using one-way ANOVA. Treatment had a significant effect on load-to-failure (p=0.004) with ZA strengthening the healthy and osteolytic vertebrae. Reduced strength post SBRT seen in the metastatic (but not the healthy) group may be explained by greater tumor involvement secondary to higher cell injection concentrations. Untreated metastatic samples had higher DV/BV (16.25±2.54%) compared to all treatment groups (p<0.05) suggesting a benefit of treatment to bone quality. Focal and systemic cancer treatments were shown to effect load-to-failure and microdamage accumulation in healthy and osteolytic vertebrae. Developing a better understanding of how treatments effect bone quality and mechanical stability is critical for effective management of patients with spinal metastases

Abstract. Objective. There is no specific framework for the clinical management of sports related brachial plexus injuries. Necessarily, rehabilitation is based on injury presentation and clinical diagnostics but it is unclear what the underlying evidence base to inform rehabilitative management. Methods. A systematic review of the literature was undertaken in line with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We applied the PEO criteria to inform our search strategy to find articles that reported the rehabilitative management of brachial plexus injuries sustained while playing contact sports. An electronic search of Medline, CINAHL, SPORTDiscus and Web of Science from inception to 3rd November 2022 was conducted. MESH terms and Boolean operators were employed. We applied an English language restriction but no other filters. Manual searches of Google Scholar and citation searching of included manuscripts were also completed. All study types were considered for inclusion provided they were published as peer-reviewed primary research articles and contained relevant information. Two investigators independently carried out the searches, screened by title, abstract and full text. Two researchers independently extracted the data from included articles. Data was cross-checked by a third researcher to ensure consistency. To assess internal validity and risk of bias, the Joanna Briggs Institute (JBI) critical appraisal tools were utilised. Results. The search generated 88 articles. Following removal of duplicates, 43 papers were evaluated against the eligibility criteria. Nine were eligible for full text review, with the majority of exclusions being expert opinion articles. Eight case reports were included. One article reported three individuals, resulting in data for ten athletes. The mean age was 19.8 years (±4.09). Injuries occurred in five American football players, two wrestlers, two rugby players, and a basketball player. No two studies applied the same diagnostic terminology and the severity of injury varied widely. Burning pain and altered sensation was the most commonly reported symptom, alongside motor weakness in the upper limb. Clinical presentation and management differed by injury pattern. Traction injuries caused biceps motor weakness and atrophy of the deltoid region, whereas compression injuries led to rotator cuff weakness. In all cases treatment was separated into acute and rehabilitative management phases, however the time frames related to these differed. Acute interventions varied but essentially entailed soft tissue inflammation management. Rehabilitation approaches variously included strengthening of shoulder complex and cervical musculature. Return-to-play criteria was opaque. The methodological quality of the case reports was acceptable. Four met all nine of the JBI evaluation criteria, and a further three met at least 75% of items. Conclusion(s). There is a distinct lack of evidence supporting rehabilitation management of sports related brachial plexus injury. Through systematic review we found only eight reports, representing ten individual case studies. No trials, cohort studies, or even retrospective registry-based studies are available to inform clinical management, which, necessarily, is driven by expert opinion and application of basic rehabilitation principles. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project

Some activities of daily living require that the head be kept level during axial rotation of the cervical spine (Kinematically Constrained Axial Rotation). One such activity is looking over one's shoulder when walking or driving. The kinematic constraint of keeping the head level during axial rotation means that the segmental axis of rotation may not be aligned with the global axis of rotation of the cervical spine. Most of the literature on cervical spine axial rotation is based on experiments where the segmental axis of rotation is aligned with the global axis of rotation (Traditional Axial Rotation). There are only a few clinical and biomechanical studies that have examined kinematically constrained cervical axial rotation. We performed a series of biomechanical experiments in which we tested cervical spines in traditional and kinematically constrained axial rotation. The resulting primary and coupled motions of the segments showed that kinematically constrained axial rotation is distinct from traditional axial rotation. Our findings and the findings of other kinematically constrained axial rotation studies will be compared and contrasted with data from traditional axial rotation studies

Introduction and Objective. The treatment of severe deformities often requiring aggressive techniques such as vertebral resection and osteotomies with high comorbidity. To mitigate this risk, several methods have been used to achieve a partial reduction of stiff curves. The objective of this study was to evaluate and quantify the effectiveness of the Perioperative Halo-Gravity Traction (HGT) in the Treatment of Severe Spinal Deformity in Children. Materials and Methods. A historical cohort of consecutive childs with severe spinal deformity who underwent to a perioperative HGT as a part of the treatment protocol. Minimum follow-up of 2 years. Demographic, clinical and radiological data, including time duration of perioperative HGT and Cobb angle in the coronal and sagittal plane. The radiological variables were measured before the placement of the halo, after placement of the halo, at the end of the period of traction, after surgery and in the final follow-up. Results. Seventeen males (57%) and twenty females (43%) were included in the final analysis. The mean age was 6.5 years (SD 4.8). The most frequent etiology for the spinal deformity was syndromic (13 patients). The average preoperative Cobb angle was 88º (range, 12–135). HGT was used in 17 cases prior to a primary surgery and in 20 cases prior to a revision surgery. After the HGT, an average correction of 34% of the deformity was achieved (p <0.05). After the surgery this correction improved. At 2-year follow-up there was a correction loss of 20% (p <0.05). There were 3 complications (8.1%): 2 pin infections and cervical subluxation. Conclusions. The application of HGT in cases of severe rigid deformity is useful allowing a correction of the preoperative deformity of 34%, facilitating surgery. Preoperative HGT seems to be a safe and effective intervention in pediatric patients with high degree deformity

Summary. Bi-plane Image matching method is very useful technique to evaluate the loaded 3D motion of each cervical level. Introduction. Cervical orthoses are commonly used to regulate the motion of cervical spines for conservative treatment of injuries and for post-operative immobilization. Previous studies have reported the efficacy of orthoses for 2D flex-extension or 3D motions of the entire cervical spine. However, the ability of cervical orthoses to reduce motion might be different at each intervertebral level and for different types of motion (flexion-extension, rotation, lateral bending). The effectiveness of immobilizing orthoses at each cervical intervertebral level for 3D motions has not been reported. The purpose of this study is to evaluate the effectiveness of the Philadelphia collar to each level of cervical spines with 3D motion analysis under loading condition. Patients & Methods. Patient Sample: Four asymptomatic volunteer subjects were recruited and provided informed consent. Approval of the experimental design by the institutional review board was obtained. These 4 individuals were without any history of cervical diseases or procedures. The presence of any symptoms, spinal disorders and anatomical abnormalities in fluoroscopic images or CT was a criterion of exclusion from this study. Outcome Measures: To evaluate the efficacy of the Philadelphia collar, ANOVA was used to compare the range of motion with and without collar at the C3/4, C4/5, C5/6 and C6/7 intervertebral levels for each motion. The level of statistical significance was set at p<0.05. When a statistical difference was detected, post hoc Tukey tests were performed. Methods. Three-dimensional models of the C3-C7 vertebrae were developed from CT scans of each subject using commercial software. Two fluoroscopy systems were positioned to acquire orthogonal images of the cervical spine. The subject was seated within the view of the dual fluoroscopic imaging system. Pairs of images were taken in each of 7 positions: neutral posture, maximum flexion and extension, maximum left and right lateral bending, and maximum left and right rotation. The images and 3D vertebral models were imported into biplane 2D-3D registration software, where the vertebral models were projected onto the pair of digitised images and the 3D bone pose was adjusted to match its radiographic projection in each image. Relative motions between each vertebral body were calculated from body-fixed coordinate systems using a flexion-lateral bending-axial rotation Cardan angle sequence. Results. Flexion range was significantly reduced with the collar at each cervical level. Extension range was significantly reduced at the C3/4 level. Rotation and lateral bending were reduced for C3/4, C4/5, C5/6 levels with the collar. Discussion/Conclusion. The Philadelphia Collar significantly reduces cervical motion at C3/4, C4/5 and C5/6 levels in almost all motions (except for extension). At the C6/7 level, this type of collar has limited effectiveness reducing cervical motion. We used 3D radiographic measurements to quantify the effectiveness of the Philadelphia collar for reducing cervical motion. Bi-plane 2D-3D registration method is useful technique to evaluate 3D motion of cervical spines

Introduction and Objective. Aneurysmal bone cyst (ABC) of the spine is a locally aggressive benign lesion which can be treated by en bloc resection with wide margin to reduce the risk of local recurrence. To avoid morbidity associated with surgery, selective arterial embolization (SAE) can be considered the first-line treatment for ABCs of the spine. Other emerging treatments for ABCs include bisphosphonates, percutaneous doxycycline, sclerotherapy and Denosumab. In addition, we previously introduced the use of autologous bone marrow concentrate (BMC) injection therapy to stimulate bone healing and regeneration in ABC of the spine. One of the potential advantages of such a method is that surgical treatments are not necessary, thus allowing for both a minimally invasive approach and the treatment of poorly accessible lesions. In this prospective study we described the clinical and radiological outcomes of percutaneous injection of autologous BMC in a series of patients affected by ABCs of the spine and followed for at least one year. Materials and Methods. Fourteen patients (6 male, 8 female) were treated between June 2014 to December 2019 with BMC injection for ABC of the spine. The mean age was 17.85 years. The mean follow up was 37.4 months (range 12– 60 months). The dimension of the cyst and the degree of ossification were measured by Computed Tomography (CT) scans before the treatment and during follow-up visits. Results. Six patients received a single dose of BMC, five patients received two doses and in three patients three doses of BMC were administered. The mean ossification of the cyst (expressed in Hounsfield units) increased statistically from 43.48±2.36 HU to 161.71±23.48 HU during follow-up time and the ossification was associated to an improvement of the clinical outcomes. The mean ossification over time was significantly higher in patients treated with a single injection compared to patients treated with multiple injections. No significant difference in ossification was found between cervical and non-cervical localization of the cyst. Moreover, the initial size of the cyst was not statistically associated with the degree of ossification during follow-up. We also observed that five out of six female patients (83.3%) were less than sixteen years old and four of these (66.7%) were managed with a single dose of BMC injection, while a higher percentage of male patients (6/8, 75%) were more than sixteen years old and more than one injection was administered to them. Conclusions. The results of this study reinforce our previous evidence on the use of BMC as a valid alternative for spinal ABC management when SAE is contraindicated or ineffective. The initial size of the cyst and its localization does not influence the efficacy of the treatment. However, BMC injection could be indicated as treatment of choice for spinal ABC in young adolescent women

Introduction and Objective. Postoperative pain control in shoulder surgery is challenging even in arthroscopic procedures. Acute postoperative pain can last up to 48hrs despite using multimodal analgesia. Different techniques have been used to control acute pain following shoulder surgery. The most common technique currently used in shoulder surgery at the elective orthopaedic centre in Leeds is a combination of general anaesthetic (GA) and interscalene block (ISB). ISB maybe very effective, however, carries many risks and potential side effects such as brachial plexus injury and paralysis of the vagus and laryngeal recurrent nerves as well as cervical sympathetic nerve and pneumothorax. ISB can also be associated with higher incidence of neurological deficit compared to other peripheral nerve blocks; up to 14% at 10 days in some cases. As such we decided to examine the use of ISB for achieving pain control in our elective unit. Materials and Methods. A prospective consecutive series of 217 patients undergoing shoulder surgery were studied. These were grouped into 10 groups. All procedures were arthroscopic apart from shoulder arthroplasty procedures such as hemiarthroplasty and total shoulder replacements (TSRs). The choice of regional anaesthesia was ISB with GA as standard practice. Visual analogue scores (VAS) at 0hrs, 1hr, 2hrs, 4hrs and 6hrs; and total opiates intake were recorded. A one-way single factor ANOVA was used as preferred statistical analytical method to determine whether there is a difference in VAS scores and total opiates intake amongst the groups. Postoperative analgesics were used for pain relief, although these were not standardised. Results. In total shoulder replacement group, although the RSR group used more morphine on average compared to the ASR group (Mean morphine intake 6.5mg vs 3mg), this was not statistically significant (F<Fcrit; p value= 0.19). When comparing all the arthroplasty groups, the difference in mean morphine intake was also statistically not significant (F<Fcrit; p value=0.24). However, when comparing all 10 groups’ morphine intake there was a statistically significant difference amongst these groups (F>F crit; p value=0.03). Interestingly, there was a statistically significant difference in VAS at 0hrs (F>Fcrit p value=0.01); 1hrs (F>Fcrit; p value=0.00), and at 6hrs (F>Fcrit; p value=0.02) when comparing all 10 groups. Conclusions. ISB is an effective technique in achieving pain control in shoulder surgery; however, there are still variations in analgesic needs amongst groups and the use of alternative techniques should be thus explored. A future prospective study looking at acute pain for a longer period of time after shoulder surgery would explore the effectiveness of ISB in achieving pain control consistent with rehabilitation requirements

Cervical and lumbar spine fusion procedures are increasing every year. Nonetheless, these procedures are associated with high infection rates, resulting in additional cost burden. The conundrum of achieving efficient spinal fusions with minimum complications requires an ideal bone graft with osteoconductive, osteoinductive, osteogenic and structural characteristics. Synthetic bone graft substitutes with or without autograft, allograft or synthetic bone substitutes have been commonly used for fusion procedures. We carried out a meta-analysis of comparative studies and prospective case series (n = 29) with cervical and lumbar fusion procedures using synthetic bone graft substitutes, autograft or allograft and other biologics. Synthetic bone graft substitutes analysed included HA (Hydroxyapatite), β-TPC (Tri Calcium Phosphate), β-TSC (Tri Calcium Sulfate), PMMA (Polymethylmetacrylate), Surgibone, BOP (Biocompatible Osteoconductive Polymer). The analysis revealed suboptimal evidence for the efficacy and safety of synthetic products used in spinal fusion procedures. Further studies are needed to determine beneficial effects of synthetic substitutes. However, the infection rate could be highly decreased with surface and composition modification of widely used polyether ether ketone (PEEK) implants. Laser modification of surface characteristics and collagen fleeces with micro and nano pore structures can prove to be excellent surface for increased osteoblasts cell proliferation and vitality

Abstract. Objective. Spinal cord surgery is a technically challenging endeavour with potentially devastating complications for patients and surgeons. Intra-operative neurophysiological monitoring(IONM), or spinal cord monitoring (SCM), is one method of preventing and identifying damage to the spinal cord. At present, indications for its use are based more on individual surgeon preference and for medico legal purposes. Our study aimed to determine IONM's utility as a clinical tool. Methods. This is a retrospective case series of 169 patients who underwent spinal surgery with IONM at two institutions between 2013 and 2018. Signal changes detected were recorded as well as the surgeon's response to these changes. Patients were followed up to one-year post-surgery using our institution's EVOLVE system. The main outcome measure in this study was new post-operative neurological signs and/or symptoms and what effect, if any, IONM and subsequent surgeon intervention had on these complications. Result. Indications for IONM included cervical stenosis, cervical disc prolapse, unstable fractures and bony metastases. Signal changes were observed in 33% (n=55) of cases. 24 of these patients responded to re-positioning. There were 7 total complications with full resolution by 12 months. False negative rate was 2.4% (n=4). There was one true positive. The largest cohort of patients included those who experienced no signal changes and subsequently no post-operative deficits (n=124). Conclusion. IONM is a non-invasive clinical tool that may be utilised for medicolegal reasons. Its use as a clinical tool is questionable given its relatively high false negative rate and low false positive rate. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project

Summary Statement. Tandem stenosis is a prevalent condition in an Asian population with the narrowest cervical canal diameters and risk factors include advanced age and increased levels of lumbar canal stenosis. Introduction. Tandem spinal stenosis (TSS) is defined as patient with concomitant spinal canal stenosis found in both cervical (C) and lumbar (L) spinal region. Few studies have reported the incidence of TSS is ranged from 5–25%, but these are all noncomparative, small cohort studies. To the best of author knowledge this is the 1st study aims to compare the prevalence of TSS and its risk factors of development in a large multiracial Asian population. Methods. A retrospective review of all mid-sagittal T2MRI whole spine image was carried out at a University hospital in year 2007. Patients with spinal tumour, fracture and congenital stenosis were excluded. Spinal stenosis was defined as canal diameter of ≤10mm, measured from the posterior cervical vertebral/disc wall to anterior surface of the corresponding lamina. Patients were divided into 4 groups, no stenosis(NS), lumbar stenosis only(LS), cervical stenosis only(CS) and TSS. Patients’ demographics, race, co-morbidities and lumbar radiological report data were examined. Potential risk factors for the development of TSS were analyzed using SPSS software. Results. 926 (479 male, 447 female) patients with average age 50 (20–96) yrs were studied. Cervical canal diameters (mm) in TSS patients were the narrowest among the 4groups with C2/3 disc: 11.6, C3/4: 9.7, C4/5: 9.4, C5/6: 8.9, C6/7: 10.0 and C7T1: 11.4mm. The incidence of TSS was 26.2%. The prevalence of TSS in Chinese was 30.7%, Indian 12.5%, Malay 22.5%. The TSS prevalence in patients with 1 level lumbar canal stenosis was 12.5%, 2 levels lumbar stenosis was 6.4% and 3 levels was 4.1%. Multivariate analysis showed patients aged between 40–59 yrs (p=0.000, Exp(B):5.8, 95%CI 2.8–12.0), aged > 60yrs (p=0.000, Exp(B): 10.5, 95%CI 4.8–22.9), Chinese race (p=0.008, Exp(B): 2.5, 95%CI 1.3–4.9), patients with 1 level lumbar stenosis (p=0.000, Exp(B): 63.3, 95%CI 29.2–137.3), 2 levels lumbar stenosis (p=0.000, Exp(B): 67.7, 95%CI 29.4–155.7) and 3 levels lumbar stenosis (p=0.000, Exp(B): 106.6, 95%CI 43.6–260.5) are statistical significant risk factors for TSS development. Conclusion. The incidence of TSS was 26.2%. TSS patients have the narrowest cervical canal measurements among the studied groups. The prevalence of TSS in Chinese is the highest (30.7%). Patients advancing in age or have increased levels of lumbar canal stenosis are at risk of developing TSS

Clinical investigations show that the cervical spine presents wide inter-individual variability, where its motion patterns and load sharing strongly depend on the anatomy. The magnitude and scope of cervical diseases, including disc degeneration, stenosis, and spondylolisthesis, constitute serious health and socioeconomic challenges that continue to increase along with the world”s growing aging population. Although complex exact finite element (FE) modeling is feasible and reliable for biomechanical studies, its clinical application has been limited as it is time-consuming and constrained to the input geometry, typically based on one or few subjects. The objective of this study was twofold: first to develop a validated parametric subject-specific FE model that automatically updates the geometry of the lower cervical spine based on different individuals; and second to investigate the motion patterns and biomechanics associated with typical cervical spine diseases. Six healthy volunteers participated in this study upon informed consent. 26 parameters were identified and measured for each vertebra in the lower cervical spine from Lateral and AP radiographs in neutral, flexion and extension viewpoints in the standing position. The lower cervical FE model was developed including the typical vertebrae (C3-C7), intervertebral discs, facet joints, and ligaments using ANSYS (PA, USA). In order to validate the FE model, the bottom surface of C7 was fixed, and a 73.6N preload together with a 1.8 N.m pure moment were input into the model in both flexion and extension. The results were compared to experimental studies from literature. Disc degeneration disease (DDD) was used as an example, where the geometry of C5-C6 disc was changed in the model to simulate 3 different grades of disc degeneration (mimicking grades 1 to 3), and the resulting biomechanical responses were evaluated. The average ranges of motion (ROM) were found to be 4.84 (±0.73) degrees and 5.36 (±0.68) degrees for flexion and extension for C5-C6 functional unit, respectively, in alignment with literature. The total ROM of the model with disc generation grades 2 and 3 was found to have decreased significantly as compared to the intact model. In contrast, the axial stresses on the degenerated discs were significantly higher than the intact discs for all 3 degeneration grades. Our preliminary results show that this novel validated subject-specific FE model provides a potential valuable tool for noninvasive time and cost effective analyses of cervical spine biomechanical (kinematic and kinetic) changes associated with various diseases. The model also provides an opportunity for clinicians to use quantitative data towards subject-specific informed therapy and surgical planning. Ongoing and future work includes expanding the studied population to investigate individuals with different cervical spine afflictions