A Comparison between Structural Allografts and Polyetheretherketone Interbody Spacers Used in Anterior Cervical Discectomy and Fusion: A Systematic Review and Meta-analysis.

Among interbody implants used during anterior cervical discectomy and fusion (ACDF), structural allografts and polyetheretherketone (PEEK) are the most used spacers. Currently, no consensus has been established regarding the superiority of either implant, with US surgeons preferring structural allografts, whereas UK surgeons preferring PEEK. The purpose of this systematic review (level of evidence, 4) was to compare postoperative and patient-reported outcomes between the use of structural allografts PEEK interbody spacers during ACDF. Five electronic databases (PubMed, Embase, Scopus, Web of Science, and Cochrane) were searched for articles comparing the usage of structural allograft and PEEK interbody spacers during ACDF procedures from inception to April 10, 2023. The searches were conducted using the keywords "Spine," "Allograft," and "PEEK" and were performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines. Subsequent quality and sensitivity analyses were performed on the included studies. Nine studies involving 1,074 patients were included. Compared with the PEEK group, the structural allograft group had comparable rates of postoperative pseudoarthrosis (p=0.58). However, when stratified according to the number of levels treated, the 3-level ACDF PEEK group was 3.45 times more likely to have postoperative pseudoarthrosis than the structural allograft group (p=0.01). Subsequent postoperative outcomes (rate of subsidence and change in the preoperative and postoperative segmental disc heights) were comparable between the PEEK and structural allograft groups. Patient-reported outcomes (Visual Analog Scale [VAS] of neck pain and Neck Disability Index [NDI]) were comparable. This study showed that for 3-level ACDFs, the use of structural allografts may confer higher fusion rates. However, VAS neck pain, NDI, and subsidence rates were comparable between structural allografts and PEEK cages. In addition, no significant difference in pseudoarthrosis rates was found between PEEK cages and structural allografts in patients undergoing 1- and 2-level ACDFs.

Changes in Spinopelvic Parameters Between Standing and Sitting Postures: A Systematic Review and Meta-analysis.

STUDY DESIGN: Systematic review and meta-analysis. OBJECTIVE: To report the ratio-of-differences between standing and sitting. To understand how sex and age influence these differences. SUMMARY OF BACKGROUND DATA: Currently, spinal deformity surgery aims to realign the sagittal profile of the spine with-reference-to the standing posture resulting in overcorrection. New studies report significant disparities between standing and sitting spinal alignment. METHODS: A comprehensive search and review of the published literature was performed on 4 platforms in accordance with the PRISMA 2009 checklist by 2 authors independently. RESULTS: From 753 abstracts extracted from the databases, 38 papers involving 5423 patients were identified. sagittal vertical axis was more positive in sitting, with a pooled mean difference of 29.5 mm (95% CI: 17.9-41.0). Pelvic tilt (PT) was larger in sitting, with a pooled mean difference of 16.7 degrees (95% CI: 12.5-20.9), and a pooled odds ratio of 1.2(95% CI:1.1-1.3. P =0.001). Sacral Slope (SS) was smaller and lumbar lordosis (LL) was less lordotic in sitting, with a pooled mean difference of 15.0 degrees (95% CI: 11.918.1) and 21.1 degrees (95% CI:14.5-27.8), respectively, and a pooled odds ratio of 0.7 (95% CI: 0.6-0.8. P <0.001) and 0.7 (95% CI:0.6-0.7, P <0.001), respectively. Pelvic incidence and thoracic kyphosis was similar in sitting. Subgroup meta-analysis comparing odd ratio of standing to sitting showed: Among younger patients (age younger than 50), the PT and LL pooled odds-ratios were 1.4 and 0.7, respectively. Among older patients (age older than or equal to 50), the PT and LL pooled odds-ratios were 1.1 and 0.8, respectively. Among female patients, the SS pooled odds ratio was 0.6. Among male patients, the SS pooled odds ratio was 0.7. CONCLUSION: When comparing sitting to standing, it gives a more positive sagittal vertical axis, a smaller SS and LL, and a larger PT. pelvic incidence and thoracic kyphosis remained similar. Younger and female patients have pronounced differences in SS, PT, and LL, suggesting the existence of age and sex variations, and its role to be considered when planning for spinal realignment surgeries. Clinical outcome studies are required to ascertain the impact of these findings.

Ag nanoparticle modified porous Si microspheres as high-performance anodes for Li-ion batteries.

This study aimed to address the challenges associated with silicon (Si) anode materials in Li-ion batteries, such as their large volume effect and poor electrical conductivity. To overcome these limitations, a novel composite microsphere called pSi/Ag was developed using quartz waste through a combination of high-energy ball-milling, spray drying, and magnesiothermic reduction techniques. The morphology and structure of the pSi/Ag composite were thoroughly characterized using various methods, including X-ray diffraction, field-emission scanning electron microscopy, and transmission electron microscopy. The results revealed that the Ag nanoparticles were uniformly dispersed within the porous micron-sized Si sphere particles, leading to enhanced electrochemical performance compared to pure porous silicon that did not undergo the spray drying process. The use of micron-sized Si prevented the excessive formation of the solid electrolyte interphase film, and the pSi/Ag-5 anode, prepared with 5 wt% AgNO3 as a precursor, demonstrated an impressive initial Coulombic efficiency of 92.8%. Moreover, a high specific capacity of 1251.4 mA h g-1 over 300 cycles at a current density of 4000 mA g-1 was attributed to the improved conductivity provided by the Ag nanoparticles in the Si matrix. The straightforward synthesis method employed in this study to produce pSi/Ag presents a promising approach for the future development of high-performance silicon anodes in Li-ion batteries.

Lin28a maintains a subset of adult muscle stem cells in an embryonic-like state.

During homeostasis and after injury, adult muscle stem cells (MuSCs) activate to mediate muscle regeneration. However, much remains unclear regarding the heterogeneous capacity of MuSCs for self-renewal and regeneration. Here, we show that Lin28a is expressed in embryonic limb bud muscle progenitors, and that a rare reserve subset of Lin28a+Pax7- skeletal MuSCs can respond to injury at adult stage by replenishing the Pax7+ MuSC pool to drive muscle regeneration. Compared with adult Pax7+ MuSCs, Lin28a+ MuSCs displayed enhanced myogenic potency in vitro and in vivo upon transplantation. The epigenome of adult Lin28a+ MuSCs showed resemblance to embryonic muscle progenitors. In addition, RNA-sequencing revealed that Lin28a+ MuSCs co-expressed higher levels of certain embryonic limb bud transcription factors, telomerase components and the p53 inhibitor Mdm4, and lower levels of myogenic differentiation markers compared to adult Pax7+ MuSCs, resulting in enhanced self-renewal and stress-response signatures. Functionally, conditional ablation and induction of Lin28a+ MuSCs in adult mice revealed that these cells are necessary and sufficient for efficient muscle regeneration. Together, our findings connect the embryonic factor Lin28a to adult stem cell self-renewal and juvenile regeneration.

Early cement augmentation may be a good treatment option for pain relief for osteoporotic compression fractures: a systematic review and meta-analysis.

PURPOSE: The incidence of osteoporotic compression fractures (VCFs) have been rising over the past decades. Presently, vertebral cement augmentation procedures such as balloon kyphoplasty and vertebroplasty are common treatments allowing pain relief and functional recovery. However, there is controversy on whether different timeframes for cement augmentation affects clinical outcomes. Hence, this study aimed to compare pain relief and complication rates between early versus late cement augmentation. METHODS: A comprehensive systematic review of PubMed, EMBASE, Scopus and Cochrane Library was conducted, identifying studies that compared early versus late cement augmentation for VCFs. As the definitions of "early" and "late" phases across studies are heterogenous, we established the cut-off between early and late phase as intervals to accommodate as many studies as possible for analysis. We conducted two separate analyses with different cut-off intervals and included studies that reported interventions within these respective time intervals. In analysis 1, we included studies which grouped patients into "early" and "late" group based on a cut-off time frame of 2-4 weeks. On the other hand, in analysis 2, we included studies which grouped patients into "early" and "late" groups based on a cut-off time frame of 6-8 weeks. Meta-analysis was conducted via random-effect models, comparing outcomes of interest between early and late groups. RESULTS: Eleven studies were included. The total cohort size was 712 and 775 patients in analysis 1 and 2 respectively. Mean follow-up was 12.9 ± 3.7 months and 11 ± 0.6 months respectively. VAS change at final follow-up was significantly greater in the early group for both analyses. (MD = - 0.66, p = 0.01; and MD = - 1.18, p < 0.005 respectively). There was no significant difference in post-operative absolute VAS score, number of cement leakage, number of adjacent compression fractures and local kyphotic angle, for both analyses. Patients in both groups experienced reductions in VAS score that exceeded the minimum clinically important difference. CONCLUSION: Both early and late timeframes for cement augmentation offered significant improvement in pain relief, with similar post-operative absolute pain score, kyphotic angle, cement leakage and adjacent vertebral fractures. Early surgery may offer substantial pain relief in patients presenting with pain as early as < 2-4 weeks of VCFs.

Prevalence and Risk Factors of Degenerative Spondylolisthesis and Retrolisthesis in the Thoracolumbar and Lumbar Spine - An EOS Study Using Updated Radiographic Parameters.

STUDY DESIGN: Single centre, cross-sectional study. OBJECTIVES: The objective is to report the prevalence of spondylolisthesis and retrolisthesis, analyse both conditions in terms of the affected levels and severity, as well as identify their risk factors. METHODS: A review of clinical data and radiographic images of consecutive spine patients seen in outpatient clinics over a 1-month period is performed. Images are obtained using the EOS® technology under standardised protocol, and radiographic measurements were performed by 2 independent, blinded spine surgeons. The prevalence of both conditions were shown and categorised based on the spinal level involvement and severity. Associated risk factors were identified. RESULTS: A total of 256 subjects (46.1% males) with 2304 discs from T9/10 to L5/S1 were studied. Their mean age was 52.2(± 18.7) years. The overall prevalence of spondylolisthesis and retrolisthesis was 25.9% and 17.1% respectively. Spondylolisthesis occurs frequently at L4/5(16.3%), and retrolisthesis at L3/4(6.8%). Majority of the patients with spondylolisthesis had a Grade I slip (84.3%), while those with retrolisthesis had a Grade I slip. The presence of spondylolisthesis was found associated with increased age (P < .001), female gender (OR: 2.310; P = .005), predominantly sitting occupations (OR:2.421; P = .008), higher American Society of Anaesthesiology grades (P = .001), and lower limb radiculopathy (OR: 2.175; P = .007). Patients with spondylolisthesis had larger Pelvic Incidence (P < .001), Pelvic Tilt (P < .001) and Knee alignment angle (P = .011), but smaller Thoracolumbar junctional angle (P = .008), Spinocoxa angle (P = .007). Retrolisthesis was associated with a larger Thoracolumbar junctional angle (P =.039). CONCLUSION: This is the first study that details the prevalence of spondylolisthesis and retrolisthesis simultaneously, using the EOS technology and updated sagittal radiographic parameters. It allows better understanding of both conditions, their mutual relationship, and associated clinical and radiographic risk factors.

"It's not you, it's me": identity disturbance as the main contributor to interpersonal problems in pathological narcissism.

BACKGROUND: Core impairments in self and other functioning typify individuals with personality disorder. While interpersonal dysfunction is a known element of narcissistic disorders, empirical research investigating intrapersonal elements is lacking. The aim of this study was to investigate the internal representations of individuals with grandiose and vulnerable features, as manifested through their attachment styles, and the specific role of identity disturbance in explaining the relationship between pathological narcissism and maladaptive interpersonal functioning. METHODS: A sample of 270 university students completed the Brief Pathological Narcissism Inventory (B-PNI), the Severity Indices of Personality Problems (SIPP), the Relationship Questionnaire (RQ), and the Inventory of Interpersonal Problems (IIP-32). RESULTS: Both vulnerable and grandiose narcissism were positively associated with both fearful and preoccupied attachment, and negatively associated with secure attachment, whilst grandiose narcissism was also positively associated with dismissive attachment. Furthermore, unstable representations of self, poor self-reflective functioning, and low sense of purpose fully mediated the relationship between interpersonal problems and grandiose narcissism while partially mediating the relationship between interpersonal problems and vulnerable narcissism. CONCLUSIONS: Overall, our findings suggest that for individuals presenting with narcissistic features, capacity for adaptive interpersonal functioning is grounded by deficits in identity integration. Implications of these findings are discussed.

A Risk Quantification Reference Table for Progressed Adolescent Idiopathic Scoliosis Surgery: An Exact Case Matched Outcomes Analysis.

STUDY DESIGN: Retrospective Exact Matched case-control study. OBJECTIVES: Surgical treatment delay in AIS due to family preferences is common. This study aims to quantify the increase in risks as the Cobb angle increases and provide a Quantifiable Risk Reference Table that can be utilized for counseling. METHODOLOGY: AIS patients were divided into 3 groups: Group A: Cobb angle 50-60°, Group 61-70°, and Group CFinal ≥80°. Each patient in Group CFinal who had curve progression were then traced-back-in-time (TBIT) to review the clinical data at earlier presentations at 50-60° (C1), and 61-70° (C2). Patient demographics, radiological, operative, and outcomes data were compared between Group A vs C1 and Group B vs Group C2. RESULTS: A total of 614 AIS surgeries were reviewed. Utilizing the EM technique, a total of 302 AIS patients were recruited. There were 147, 111, 31, and 32 patients matched in Groups A, B, C1, and C2, respectively. C2 Final patients had 34% curve pattern change, 23.2% higher incidence of requiring two surgeries, and 17.3% increase in complications. There was a statistically significant increase of 2.4 spinal levels fused, 12% increase in implant density, 35% increase in operative time, 97% increase in intra-operative blood loss, 10% loss of scoliosis correction, 40% longer hospitalization stay, and 36% increase in costs for patients who had curve progression. CONCLUSION: This study is the first to use a homogenously matched AIS cohort to provide a Quantifiable Risk Reference Table. The Risk Table provides essential knowledge for treating physicians when counseling AIS patients.

Biomechanical Comparison of a Novel 3-Screw Fixation vs Conventional 2-Screw Fixation of Calcaneal Tuberosity Avulsion Fractures.

BACKGROUND: Calcaneal tuberosity avulsion fractures are challenging to treat because of the poor bone stock and high risk of fixation failure secondary to the strong Achilles tendon pull. The purpose of this study is to compare the tensile force to failure of 2 different types of screw fixation construct in a cadaveric model of calcaneal tuberosity avulsion fracture. METHODS: An oblique osteotomy was created in the calcanei of 7 matched pairs of cadaveric specimens to simulate a tuberosity avulsion fracture and one specimen from each pair randomized into one of the 2 groups for comparison. Two cancellous screws were inserted perpendicular to the fracture line at the posteromedial and posterolateral corners of the avulsed fragment for the 2-screw construct. For the second group, an additional stab incision was made at the midline of the Achilles insertional region for a screw placed between the initial 2 screws with a trajectory toward the calcaneocuboid joint in the 3-screw construct. These specimens were then mounted and loaded to failure. RESULTS: The mean force to a predefined failure at 3.0-mm gap for the 3-screw construct was 468.7 ± 267.9 N vs 278.9 ± 164.0 N for the 2-screw construct (P < .001). The addition of a central nonparallel screw in the 3-screw construct significantly increased the force required for fracture gap displacement at all cut-off points (1.0-8.0 mm) when compared to the 2-screw construct (P < .001). Notably, the mean peak tensile force for the 3-screw construct was 499.4 ± 255.4 N occurred at the gap displacement of 4.1 mm for the 3-screw construct whereas the mean peak tensile force for the 2-screw construct was 315.9 ± 162.4 N displacing the gap at 4.3 mm. CONCLUSION: This study showed that an additional central nonparallel screw in the 3-screw construct provided significant mechanical superiority compared to a 2-screw construct. CLINICAL RELEVANCE: The present study supported the use of augmented fixation with an additional central off-axis screw to reduce risk of fixation failure in calcaneal tuberosity avulsion fractures.

Two-dimensional monitoring of a laser-solid x-ray source spot via penumbral coded aperture imaging technique.

The uncertainties of spot size and position need to be clarified for x-ray sources as they can affect the detecting precision of the x-ray probe beam in applications such as radiography. In particular, for laser-driven x-ray sources, they would be more significant as they influence the inevitable fluctuation of the driving laser pulses. Here, we have employed the penumberal coded aperture imaging technique to diagnose the two-dimensional spatial distribution of an x-ray emission source spot generated from a Cu solid target irradiated by an intense laser pulse. Taking advantage of the high detection efficiency and high spatial resolution of this technique, the x-ray source spot is characterized with a relative error of ∼5% in the full width at half maximum of the intensity profile in a single-shot mode for general laser parameters, which makes it possible to reveal the information of the unfixed spot size and position precisely. Our results show the necessity and feasibility of monitoring the spot of these novel laser-driven x-ray sources via the penumbral coded aperture imaging technique.

Femtosecond Pumping of Nuclear Isomeric States by the Coulomb Collision of Ions with Quivering Electrons.

Efficient production of nuclear isomers is critical for pioneering applications, like nuclear clocks, nuclear batteries, clean nuclear energy, and nuclear γ-ray lasers. However, due to small production cross sections and quick decays, it is extremely difficult to acquire a significant amount of isomers with short lifetimes via traditional accelerators or reactors because of low beam intensity. Here, for the first time, we experimentally present femtosecond pumping of nuclear isomeric states by the Coulomb excitation of ions with the quivering electrons induced by laser fields. Nuclei populated on the third excited state of ^{83}Kr are generated with a peak efficiency of 2.34×10^{15} particles/s from a tabletop hundred-TW laser system. It can be explained by the Coulomb excitation of ions with the quivering electrons during the interaction between laser pulses and clusters at nearly solid densities. This efficient and universal production method can be widely used for pumping isotopes with excited state lifetimes down to picoseconds, and could be a benefit for fields like nuclear transition mechanisms and nuclear γ-ray lasers.

Does Cigarette Smoking Affect Cervical Laminoplasty Clinical and Radiologic Outcomes?

STUDY DESIGN: Retrospective review. OBJECTIVE: This study aimed to investigate if smokers have both poorer early clinical and radiologic outcomes in cervical laminoplasty when compared with nonsmokers. SUMMARY OF BACKGROUND DATA: Cigarette smoking had been reported to increase rates of pseudoarthrosis following spinal instrumentation with fusion. METHODOLOGY: A retrospective review of all patients who underwent open-door cervical laminoplasty was performed. Nurick, neck pain visual analog scale, and neck disability index scores were reviewed. Cervical lordosis, range of motion (ROM), and intervertebral disc height were measured. The rates and reasons for revision surgery were recorded and classified according to the etiology of laminoplasty revision surgery. RESULTS: Sixty patients were recruited, of which 20 patients (18 males, 2 females) were smokers and 40 patients (27 males, 13 females) were nonsmokers. There was no statistically significant difference between smokers and nonsmokers in preoperative and postoperative visual analog scale, neck disability index, and Nurick scores. A trend was noted toward a greater postoperative reduction in cervical lordosis (13±8 vs. 11±11 degrees). Furthermore, 41% of smokers versus 30% in nonsmokers had >10% loss of postoperative ROM, and 59% smokers versus 50% nonsmokers had >5% loss of postoperative ROM.Postoperative complications and intervertebral disc deterioration were similar in both groups. A higher reoperation rate was noted in smokers with 6 smokers (30%) as compared with 4 nonsmokers (10%), although this did not reach statistical significance. Among the smokers, 4 (20%) were because of cervical disease progression while 2 were technique related. In nonsmokers, all 4 (10%) were because of cervical disease progression. CONCLUSION: This study showed that while there was a nonstatistically significant trend noted toward higher rates of revision surgery in smokers, the laminoplasty outcomes were not significantly poorer in smokers. In heavy smokers with multilevel cervical myelopathy, laminoplasty may be the treatment of choice over anterior spinal decompression and fusion where a high risk of pseudoarthrosis is anticipated.

Bicycle-Related Injuries of the Upper Extremity.

Background: In recent years, the increasing popularity of cycling for commuting and leisure has led to a corresponding increase in bicycle-related injuries. However, there is a lack of extensive analysis of bicycle-related injuries to the upper limb in the literature. Methods: A retrospective review of all patients with conventional bicycle-related injuries of the upper limb was performed. Data on demographics, mechanisms of injury, region of injury, fracture type, management type, and length of hospital stay were extracted and analyzed. Results: A total of 177 of 733(24%) patients with bicycle-related upper limb injuries were identified. The most common mechanism of injury was a collision with another vehicle (60%). Frequently affected regions were the shoulder (48%), hand (19%), and wrist (19%). Eighty-eight (50%) patients sustained bony injuries, while the remainder (50%) had isolated soft tissue injuries. Fifty-three (30%) patients required a mean of 3.9 days of hospitalization, whereas 13 (25%) patients required high dependency or intensive care unit treatment. Surgical interventions were required in 47 (27%) patients. Conclusion: Bicycle-related injuries to the upper limb are common and result in significant morbidity. The most common regions affected are the shoulder, wrist, and hand. Most of the injuries were caused by collisions with other vehicles. A third of affected patients required hospitalization, and a quarter required surgical intervention.

Pelvic and sacral morphology and their correlation with pelvic incidence, lumbar lordosis, and lumbar alignment changes between standing and sitting postures.

STUDY DESIGN: Retrospective Cross-Sectional Radiographic Study. OBJECTIVE: This study aims to describe novel radiographic markers of sacropelvic morphology to further define the static and dynamic relationship between the pelvis and the spine, via the analysis of two postures - standing and sitting. SUMMARY OF BACKGROUND DATA: There is increasing evidence underlining the importance of spinopelvic radiographic parameters in the holistic management of sagittal spinal deformity given the close relationship between pelvic morphology and spinal profile. METHODS: This is a retrospective radiographic study of patients who presented with the first episode of isolated mechanical, low back pain of fewer than 3 months' duration. All patients underwent whole spine radiographs using EOS technology in both standing and relaxed sitting postures. Six novel distance measurements (H1, H2, H3, V1, V2, DD) to determine pelvic dimensions, and 3 novel angles (A, B, C) to determine sacral morphology were described. RESULTS: A total of 64 males (58.2%) and 46 females (41.8%) with a mean age of 42.8 ± 18.6 (range:17-81) years old was studied. Between standing and relaxed sitting postures, differences were observed in all sagittal radiographic parameters. Multivariate analysis showed that standing LL< 500 (p = 0.008), standing V1 > 13 cm(p = 0.040), and angle B> 800(p = 0.002) are predictive of PI< 500, standing TK< 300 (p = 0.003) and PI< 500 (p = 0.006) are predictive of LL< 500, and standing PT< 170(p = 0.034), standing H3 ≥ 4 cm (p = 0.030), standing angle C< 420 (p = 0.003), sitting SS≥ 60 (p = 0.002), and sitting PT < 450 (p = 0.013) are predictive of change in LL below mean difference of 420 between standing and relaxed sitting. CONCLUSIONS: Apart from the known correlation between TK, LL and PI, low PI was found to be associated with a tall pelvis and a straight sacrum (angle B). Association between a small coccygeal inclination angle (angle C) and smaller change in LL between standing and relaxed sitting may have clinical relevance.

Beyond difficulties in self-regulation: the role of identity integration and personality functioning in young women with disordered eating behaviours.

BACKGROUND: Past research has established individual relationships between disordered eating behaviours (DEB) and both self-regulation difficulties and identity disturbance. However, no research has looked at the shared influence of these constructs on DEB nor at personality functioning in individuals with DEB. METHODS: In the present study, self-regulation was explored in terms of effortful control, impulsivity and emotion regulation while identity integration was measured in terms of impairments in self-functioning using a sample of 247 undergraduate students. RESULTS: Significant associations were found between all components of self-regulation and DEB, with the exception of impulsivity. Identity instability was also associated with self-regulation difficulties and DEB. Structural Equation Modelling analyses indicated that identity instability partially mediated the relationship between self-regulation and DEB. Lastly, disordered eating was associated with difficulties in personality functioning, with young women presenting with DEB reporting significantly greater difficulties in both self and interpersonal personality functioning. CONCLUSION: Behavioural eating anomalies should be considered as epiphenomena secondary to a possible deeper issue that reflects difficulties related to identity integration and potential personality functioning. The clinical implications of these findings are discussed.

Making a Traditional Spine Surgery Clinic Telemedicine-Ready in the "New Normal" of Coronavirus Disease 2019.

STUDY DESIGN: An original article describing a comprehensive methodology for making a traditional spine surgery clinic telemedicineready in terms of logistical considerations and workflow. PURPOSE: The aim of this study is to promote the use of telemedicine via videoconferencing to reduce human exposure to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and reduce the risk of coronavirus disease 2019 (COVID-19) transmission at outpatient clinics. OVERVIEW OF LITERATURE: The COVID-19 pandemic is the biggest healthcare crisis in the 21st century. Until a vaccine is developed or herd immunity against SARS-CoV-2 is achieved, social distancing to avoid crowding is an important strategy to reduce disease transmission and resurgence. Telemedicine has already been applied in the field of orthopedics with encouraging results. METHODS: We reviewed the evidence behind telemedicine and described our clinical protocol, patient selection criteria, and workflow for telemedicine. We discussed a simple methodology to convert pre-existing traditional clinic resources into telemedicine tools, along with future challenges. RESULTS: Our methodology was successfully and easily applied in our clinical practice, with a streamlined workflow allowing our spine surgery service to implement telemedicine as a consultation modality in line with the national recommendations of social distancing. CONCLUSIONS: Telemedicine was well incorporated into our outpatient practice using the above workflow. We believe that the use of telemedicine via videoconferencing can become part of the new normal and a safe strategy for healthcare systems as both a medical and an economic countermeasure against COVID-19.

Risk factors for surgical complications in the management of ossification of the posterior longitudinal ligament.

BACKGROUND CONTEXT: Ossification of the posterior longitudinal ligament (OPLL) is a progressive, debilitating disease most commonly affecting the cervical spine. When compared to other degenerative pathologies, OPLL procedures carry a significantly higher risk of complications owing to increased case complexity and technical difficulties. Most previous studies have focused on functional outcomes and few have reported on risk factors for postoperative complications in OPLL patients. PURPOSE: To identify clinical and radiological risk factors of surgical complications following treatment for cervical OPLL STUDY DESIGN: Retrospective review PATIENT SAMPLE: One hundred thirty-one patients with cervical myelopathy secondary to OPLL who underwent surgical decompression with complete 2-year follow-up. OUTCOME MEASURES: Surgical and medical postoperative complications were analyzed. Revision surgery rates and mortality rates were recorded. METHODS: Clinical, surgical, and radiological characteristics were collected for each patient. Complications within 30 days were identified. Univariate and multivariate analysis were performed to identify risk factors for surgical complications. RESULTS: There were 39 (29.8%) surgical complications in the cohort, which included C5 palsy (7.6%), dural tear (3.1%), surgical site infection (3.1%), and epidural hematoma (1.5%). 2-year revision and mortality rates were 4.6% and 2.3%, respectively. Univariate analysis revealed that blood loss ≥750mL (OR 3.42, p=0.028), operative duration ≥5.5 hours (OR 3.16, p=0.008), hill-type OPLL (OR 3.08, p=0.011), K-line (-) OPLL (OR 5.39, p<0.001), and presence of a double-layer sign (OR 3.79, p=0.002) were significant risk factors. In multivariate analysis, only hill-type OPLL (OR 2.61, p=0.048) and K-line (-) OPLL (OR 2.98, p=0.031) were found to be significant. Patients with both hill-type and K-line (-) OPLL had a 3.5 times risk of developing surgical complications (p=0.009). CONCLUSIONS: Patients with OPLL have a higher risk of perioperative surgical complications if they had a hill-shaped OPLL and K-line (-) OPLL on preoperative imaging studies. To the best of the authors' knowledge, this study is the first to link hill-type and K-line (-) OPLL morphology as risk factors for perioperative surgical complications.

Titanium (Ti) cages may be superior to polyetheretherketone (PEEK) cages in lumbar interbody fusion: a systematic review and meta-analysis of clinical and radiological outcomes of spinal interbody fusions using Ti versus PEEK cages.

AIM: Interbody cages are commonly used to augment interbody fusion. Commonly used materials include titanium (Ti) and polyetheretherketone (PEEK), with their inherent differences. The aim of this study is to perform a systematic review and meta-analysis to compare between the various clinical and radiological outcomes of Ti and PEEK interbody spinal cages. METHODS: A systematic review and meta-analysis comparing clinical and radiological outcomes between Ti and PEEK interbody cages in patients undergoing spinal fusion was performed. PubMed, Scopus, Web of Science, Embase, and Cochrane Central Register of Controlled Trials database were searched. All studies that compared the clinical and radiological outcomes of patients who underwent Ti and PEEK cages were included. Subgroup analyses was performed to differentiate between patients who had cervical and lumbar interbody fusion. RESULTS: A total of 11 articles were identified, with a total of 743 patients. Spinal fusion rates at final follow-up did not differ between Ti and PEEK cages (OR 1.50, 95% CI 0.57-3.94, P = 0.41), although in patients undergoing lumbar fusion, Ti cages demonstrated superior fusion (OR 2.12, 95% CI 1.05-4.28, P = 0.04). In patients with non-infective etiologies, Ti cages had a higher rate of cage subsidence (RR 2.17, 95% CI 1.13-4.16, P = 0.02). Both types of cages had similar operating time, postoperative hematoma formation, neuropathic pain, segmental angle correction and postoperative clinical outcome improvement. CONCLUSION: In non-infective lumbar spine conditions, Ti cage may be the superior option due to the higher fusion rate. LEVEL OF EVIDENCE: III.