The PAC (Post-operative Airway Compromise) score - First steps to Develop a Post-Surgery Tool for the Assessment of Upper Airway-related Complications following Anterior Cervical Spine Surgery.

BACKGROUND: Acute upper airway compromise is a rare but catastrophic complication after anterior cervical discectomy and fusion (ACDF). This study aims to develop a score to identify patients at risk for acute postoperative airway compromise (PAC). METHODS: Potential risk factors for acute PAC were selected by a modified Delphi process. Ten patients with acute PAC were identified out of 1,466 patients who underwent elective ACDF between July 2014 - May 2019. A comparison group was created by a randomized selection process (non-PAC group). Associated factors with PAC and a p-value <.10 were entered into a logistic regression model and coefficients contributed each risk factor's overall score. Calibration of the model was evaluated by Hosmer-Lemeshow (H-L) goodness-of-fit test. Quantitative discrimination was calculated and the final model was internally validated with bootstrap sampling. RESULTS: We identified 18 potential risk factors from our Delphi process, of which 6 factors demonstrated a significant association with airway compromise: age >65 years, current smoking status, ASA >2, history of a bleeding disorder, surgery of upper subaxial cervical spine (>C4), and duration of surgery >179 min. The final prediction model included five predictors with very strong performance characteristics. These five factors formed the PAC-Score (PACS) which had a range from 0 to 100. A score of 20 yielded the greatest balance of sensitivity (80%) and specificity (88%). CONCLUSIONS: The acute Postoperative Airway Compromise Score (PACS) demonstrates strong performance characteristics. The PAC score may help identify patients at risk for upper airway compromise caused by surgical site abnormalities.

Postoperative Epidural Fibrosis: Challenges and Opportunities - A Review.

Postoperative epidural fibrosis (EF) is still a major limitation to the success of spine surgery. Fibrotic adhesions in the epidural space, initiated via local trauma and inflammation, can induce difficult-to-treat pain and constitute the main cause of failed back surgery syndrome, which not uncommonly requires operative revision. Manifold agents and methods have been tested for EF relief in order to mitigate this longstanding health burden and its socioeconomic consequences. Although several promising strategies could be identified, few have thus far overcome the high translational hurdle, and there has been little change in standard clinical practice. Nonetheless, notable research progress in the field has put new exciting avenues on the horizon. In this review, we outline the etiology and pathogenesis of EF, portray its clinical and surgical presentation, and critically appraise current efforts and novel approaches toward enhanced prevention and treatment.

A novel scoring system concept for de novo spinal infection treatment, the Spinal Infection Treatment Evaluation Score (SITE Score): a proof-of-concept study.

OBJECTIVE: De novo infections of the spine are an increasing healthcare problem. The decision for nonsurgical or surgical treatment is often made case by case on the basis of physician experience, specialty, or practice affiliation rather than evidence-based medicine. To create a more systematic foundation for surgical assessments of de novo spinal infections, the authors applied a formal validation process toward developing a spinal infection scoring system using principles gained from other spine severity scoring systems like the Spine Instability Neoplastic Score, Thoracolumbar Injury Classification and Severity Score, and AO Spine classification of thoracolumbar injuries. They utilized an expert panel and literature reviews to develop a severity scale called the "Spinal Infection Treatment Evaluation Score" (SITE Score). METHODS: The authors conducted an evidence-based process of combining literature reviews, extracting key elements from previous scoring systems, and obtaining iterative expert panel input while following a formal Delphi process. The resulting basic SITE scoring system was tested on selected de novo spinal infection cases and serially refined by an international multidisciplinary expert panel. Intra- and interobserver reliabilities were calculated using the intraclass correlation coefficient (ICC) and Fleiss' and Cohen's kappa, respectively. A receiver operating characteristic analysis was performed for cutoff value analysis. The predictive validity was assessed through cross-tabulation analysis. RESULTS: The conceptual SITE scoring system combines the key variables of neurological symptoms, infection location, radiological variables for instability and impingement of neural elements, pain, and patient comorbidities. Ten patients formed the first cohort of de novo spinal infections, which was used to validate the conceptual scoring system. A second cohort of 30 patients with de novo spinal infections, including the 10 patients from the first cohort, was utilized to validate the SITE Score. Mean scores of 6.73 ± 1.5 and 6.90 ± 3.61 were found in the first and second cohorts, respectively. The ICCs for the total score were 0.989 (95% CI 0.975-0.997, p < 0.01) in the first round of scoring system validation, 0.992 (95% CI 0.981-0.998, p < 0.01) in the second round, and 0.961 (95% CI 0.929-0.980, p < 0.01) in the third round. The mean intraobserver reliability was 0.851 ± 0.089 in the third validation round. The SITE Score yielded a sensitivity of 97.77% ± 3.87% and a specificity of 95.53% ± 3.87% in the last validation round for the panel treatment decision. CONCLUSIONS: The SITE scoring concept showed statistically meaningful reliability parameters. Hopefully, this effort will provide a foundation for a future evidence-based decision aid for treating de novo spinal infections. The SITE Score showed promising inter- and intraobserver reliability. It could serve as a helpful tool to guide physicians' therapeutic decisions in managing de novo spinal infections and help in comparison studies to better understand disease severity and outcomes.

Vasoplegia Following Complex Spine Surgery: Incidence and Risk.

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: Vasoplegia is a life-threatening form of distributive or vasodilatory shock that is characterized by reduced systemic vascular resistance with resultant hypotension and normal to elevated cardiac output affecting morbidity and mortality. Vasoplegia in the context of Spine Surgery has not been described previously. The purpose of this case series is to determine incidence, risk factors, complications and postoperative outcome in patients with vasoplegia after complex multi-level thoraco-lumbar spine surgery. METHODS: A retrospective review of the electronic medical records at our institution was conducted between January 2014 and June 2018. All patients undergoing multi-level spine surgery (>6 levels) were screened for intraoperative hypotension. Patient demographics, surgical characteristics, neurological status, blood loss, risk factors, medical treatment, complications, hospital course and mortality were collected. All patients included in this study had a minimum follow-up period of 3 months. RESULTS: Out of 8521 surgically treated patients, 994 patients with multi-level thoraco-lumbar spine surgery were identified. A total of 41 patients had intraoperative hypotensive events. Of those, 5 patients with vasoplegia could be identified after elimination of all other potential contributing factors. Vasoplegia did not influence the neurological outcome. One major and three minor complications occurred. All patients showed full recovery. The risk factors identified for vasoplegia include prolonged surgery with osteotomies. CONCLUSIONS: Vasoplegia is a rare condition with an incidence of .6%. Patients experiencing vasoplegia did not appear to experience worse surgical outcomes. The use of special intraoperative hemodynamic monitoring should be considered in selected cases.

Olfactory Stem Cells for the Treatment of Spinal Cord Injury-A New Pathway to the Cure?

OBJECTIVE: Because full functional recovery after spinal cord injury (SCI) remains a major challenge, stem cell therapies represent promising strategies to improve neurologic functions after SCI. The olfactory mucosa (OM) displays an attractive source of multipotent cells for regenerative approaches and is easily accessible by biopsies because of its exposed location. The regenerative capacity of the resident olfactory stem cells (OSCs) has been demonstrated in animal as well as clinical studies. This study aims to demonstrate the feasibility of isolation, purification and cultivation of OSCs. METHODS: OM specimens were taken dorso-posterior from nasal middle turbinate. OSCs were isolated and purified using the neurosphere assay. Differentiation capacity of the OSCs in neural lineage and their behavior in a plasma clot matrix were investigated. RESULTS: Our study demonstrated that OSCs differentiated into neural lineage and were positive for GFAP as well as ß-III tubulin. Furthermore, OSCs were viable and proliferated in a plasma clot matrix. CONCLUSIONS: Because there are no standard methods for purification, characterization, and delivery of OSCs to the injury site, which is a prerequisite for the clinical approval, this study focuses on the establishment of appropriate methods and underlines the high potential of the OM for autologous cell therapeutic approaches.

Iliac Screw Fixation Revisited: Improved Clinical and Radiologic Outcomes Using a Modified Iliac Screw Fixation Technique.

STUDY DESIGN: A retrospective study. OBJECTIVE: To describe the modified iliac screw (mILS) technique and compare it to other spinopelvic fixation techniques in terms of wound healing complications, hardware prominence, and failure. SUMMARY OF BACKGROUND DATA: The traditional entry point of an iliac screw often causes postoperative gluteal pain from the prominent screw head. The use of an offset connector also adds a point of weakness to the construct. By choosing a different screw entry point offset connectors can be avoided, and the screw head itself is less prominent, thereby reducing postoperative discomfort. MATERIALS AND METHODS: A retrospective analysis was performed of adult patients undergoing lumbopelvic fixation (LPF) between January 2014 and June 2019. Patients were grouped into 1 of 3 groups based on the technique of pelvic fixation: S2 alar-iliac (S2AI) screw, traditional iliac screw (tILS), and mILS. The primary outcome parameter was the minimal distance from screw head to skin. Secondary outcome parameters were instrumentation loosening/failure, adjacent level fractures, pseudoarthrosis, and medial or lateral iliac screw perforation. RESULTS: A total of 190 patients undergoing LPF were included in the following 3 groups: mILS group (n=113), tILS group (n=40), and S2AI group (n=37). The mean minimal distance from screw head to skin in the mILS group was 31.3 mm compared with 23.7 mm in the tILS group (P<0.00199). No statistically significant differences were found when comparing the 3 groups with respect to complications. The mILS group did not show any cases of prominent instrumentation and had the lowest rate of instrumentation failure. CONCLUSIONS: The mILS technique is an acceptable alternative for LPF, offering the benefits of iliac screw fixation while avoiding offset connectors and screw prominence complications associated with tILS. LEVEL OF EVIDENCE: Level III.

Rehabilitation during early postoperative period following total knee arthroplasty using single-joint hybrid assistive limb as new therapy device: a randomized, controlled clinical pilot study.

INTRODUCTION: The first weeks after total knee arthroplasty (TKA) are crucial for the functional outcome. To improve knee mobility, a continuous passive motion (CPM) motor rail is commonly used during in-hospital rehabilitation. The single-joint hybrid assistive limb (HAL-SJ) is a new therapy device. The aim of the study was to improve patients' range of motion (ROM), mobility, and satisfaction using the active-assistive support of the HAL-SJ. MATERIALS AND METHODS: Between 09/2017 and 10/2020, 34 patients, who underwent TKA and matched the inclusion criteria, were randomized into study (HAL-SJ) and control (CPM) group. Treatment began after drain removal and was carried out until discharge. Primary outcome parameters were raised pre- and postoperatively and included the Oxford knee score (OKS), visual analog scale (VAS), and acquired range of motion. Furthermore complications caused by the device were recorded. RESULTS: OKS increased in both groups postoperatively, but only significantly in the HAL-SJ group. Postoperative pain improved in both groups without significant differences. Flexion improvement was significant in both groups between days 3/7 and 8 weeks postoperatively. We did not encounter any complications related to HAL-SJ. CONCLUSIONS: In conclusion, use of the HAL-SJ during rehabilitation in the early postoperative period after TKA was safe without disadvantages compared to the control group and seems to have advantages in terms of daily life impairment.

A novel anatomo-physiologic high-grade spondylolisthesis model to evaluate L5 nerve stretch injury after spondylolisthesis reduction.

L5 nerve palsy is a well-known complication following reduction of high-grade spondylolisthesis. While several mechanisms for its occurrence have been proposed, the hypothesis of L5 nerve root strain or displacement secondary to mechanical reduction remains poorly studied. The aim of this cadaveric study is to determine changes in morphologic parameters of the L5 nerve root during simulated intraoperative reduction of high-grade spondylolisthesis. A standard posterior approach to the lumbosacral junction was performed in eight fresh-frozen cadavers with lumbosacral or lumbopelvic screw fixation. Wide decompressions of the spinal canal and L5 nerve roots with complete facetectomies were accomplished with full exposure of the L5 nerve roots. A 100% translational slip was provoked by release of the iliolumbar ligaments and cutting the disc with the attached anterior longitudinal ligament. To evaluate the path of the L5 nerves during reduction maneuvers, metal bars were inserted bilaterally at the inferomedial aspects of the L5 pedicle at a distance of 10 mm from the midpoint of the L5 pedicle screws. There was no measurable change in length of the L5 nerve roots after 50% and 100% reduction of spondylolisthesis. Mechanical strain or displacement during reduction is an unlikely cause of L5 nerve root injury. Further anatomical or physiological studies are necessary to explore alternative mechanisms of L5 nerve palsy in the setting of high-grade spondylolisthesis correction, and surgeons should favor extensive surgical decompression of the L5 nerve roots when feasible.

Influence of an on-body lifting aid (HAL® for Care Support) on kinematics during repetitive lifting in healthy men.

Work-related lower back pain (LBP) leads to socio-economic burden and demands solutions. The hybrid assistive limb (HAL) for Care Support (Cyberdyne Inc., Ibaraki, Japan) is an active on-body lifting aid to assist joint motion according to the wearer's voluntary motor drive to reduce the lumbar load. A few studies investigated HAL and stated efficacy in terms of enhanced performance and reduced fatigue, yet the question remained if the use of HAL may result in a different execution of movement, for example by influencing the kinematics of the lower extremities. The aim of this study was to determine the influence of HAL on kinematics of the lower limbs and the spinal column during repetitive freestyle symmetrical lifting. Kinematic data was recorded by an inertial measurement unit sensor system in 11 healthy men lifting and lowering a 19.5 kg barbell under three conditions (no HAL, HAL Level 3/5, HAL Level 5/5). Outcome parameters were maximum and minimum angles as well as range of motion (ROM) of thoracic spine, lumbar spine, hip- and knee joint in sagittal plane. We found a significantly decreased ROM of the lumbar spine as well as a significantly reduced maximum and minimum thorax extension when starting lifting and in upright position after lifting, respectively, while using HAL. Influence of HAL on the kinematics of the lower limbs was not significant. Differences between both evaluated HAL conditions were not significant. This study proved limited lumbar spine ROM and reduced thorax extension without alterations of lower limbs kinematics when using HAL. This might potentially decrease the risk of work-related LBP.

Rates of early complications and mortality in patients older than 80 years of age after surgical treatment of acute traumatic spinal fractures: ankylosing spondylitis versus osteoporosis.

OBJECTIVE: The purpose of this retrospective cohort study was to analyze the early complications and mortality associated with multilevel spine surgery for unstable fractures in patients older than 80 years of age with ankylosing spondylitis and to compare the results with an age- and sex-matched cohort of patients with unstable osteoporotic fractures. METHODS: A retrospective review of the electronic medical records at a single institution was conducted between January 2014 and December 2019. Patient demographics, surgical characteristics, complications, hospital course, and 90-day mortality were collected. Comorbidities were stratified using the age-adjusted Charlson Comorbidity Index (CCI). RESULTS: Among 11,361 surgically treated patients, 22 patients with ankylosing spondylitis (AS group) and 24 patients with osteoporosis (OS group) were identified. The mean ages were 83.1 ± 3.1 years and 83.2 ± 2.6 years, respectively. A significant difference in the mean CCI score was found (7.6 vs 5.6; p < 0.001). Multilevel posterior fusion procedures were conducted in all patients, with 6.7 ± 1.4 fused levels in the AS group and 7.1 ± 1.1 levels fused in the OS group (p > 0.05). Major complications developed in 10 patients (45%) in the AS group compared with 4 patients (17%) in the OS group (p < 0.05). The 90-day mortality was 36% in the AS group compared with 0% in the OS group (p < 0.001). CONCLUSIONS: Patients older than 80 years of age with AS bear a high risk of adverse events after multilevel spinal fusion procedures. The high morbidity and 90-day mortality should be clearly discussed and carefully weighed against surgical treatment.

Surgical Management of Charcot Spinal Arthropathy in the Face of Possible Infection.

BACKGROUND: The design is a retrospective cohort study. Charcot spinal arthropathy (CSA) is a rare and poorly understood progressive destructive spine condition that usually affects patients with preexisting spinal cord injury. The complexity of this condition, especially when additionally burdened by superimposed infection in the CSA zone, can potentially lead to suboptimal management such as protracted antibiotic therapy, predisposition to hardware failure, and pseudarthrosis. While in noninfected CSA primary stabilization is the major goal, staged surgical management has not been stratified based upon presence of a superinfected CSA. We compare clinical and radiological outcomes of surgical treatment in CSA patients with and without concurrent spinal infections. METHODS: Our single-institution database was reviewed for all patients diagnosed with CSA and surgically treated, who were subsequently divided into 2 cohorts: spinal arthropathy with superimposed infection and those without. Those were comparatively studied for complications and reoperation rate. RESULTS: Fifteen patients with CSA underwent surgical intervention; mean follow up of 15.3 months (range, 0-43). Eleven patients received stabilization with a quadruple-rod thoracolumbopelvic construct, while 4 patients with superinfected CSA underwent a staged procedure. Patients treated with a staged approach experienced fewer intraoperative complications (0% versus 18%) and fewer revision surgeries (25% versus 36%). Both cohorts had the same eventual healing. CONCLUSIONS: Surgical management in CSA patients with primary emphasis on stability and modified surgical treatment based on presence of an active infection in the zone of neuropathic destruction will lead to similar eventual successful results with relatively few and manageable complications in this challenging patient population. LEVEL OF EVIDENCE: 4. CLINICAL RELEVANCE: The proposed treatment algorithm including the use of a quadruple-rod construct with lumbopelivic fixation and a staged approach in patients with superinfected CSA represents a reasonable option in the surgical treatment of CSA.

Fixation Strength of Modified Iliac Screw Trajectory Compared to Traditional Iliac and S2 Alar-Iliac Trajectories: A Cadaveric Study.

OBJECTIVE: Traditional iliac (TI) screws require extensive dissection, involve offset-connectors, and have prominent screw heads that may cause patient discomfort. S2 alar-iliac (S2AI) screws require less dissection, do not need offset connectors, and are less prominent. However, the biomechanical consequences of S2AI screws crossing the alar-iliac joint is unknown. The present study investigates the fixation strength of a modified iliac (MI) screw, which has a more medial entry point and reduced screw prominence, but does not cross the alar-iliac joint. METHODS: Eighteen sacropelvic spines were divided into 3 groups (n = 6): TI, S2AI, and MI. Each specimen was fixed unilaterally with S1 pedicle screws and pelvic fixation according to its group. Screws were loaded at ±10 Nm at 3Hz for 1000 cycles. Motion of each screw and rod strain above and below the S1 screw was measured. RESULTS: Toggle of the S1 screw was lowest for the TI group, followed by the MI and S2AI groups, but there were no significant differences (P = 0.421). Toggle of the iliac screw relative to the pelvis was also lowest for the TI group, followed by the MI group, and was greatest for the S2AI group, without significant differences (P = 0.179). Rod strain was similar across all groups. CONCLUSIONS: No statistically significant differences were found between the TI, S2AI, and MI techniques with regard to screw toggle or rod strain. Advantages of the MI screw include its lower profile and a medialized starting point eliminating the need for offset-connectors.

Risk Factors Associated with 90-day Readmissions Following Odontoid Fractures: A Nationwide Readmissions Database Study.

STUDY DESIGN: Nationwide Readmissions Database Study. OBJECTIVE: The aim of this study was to investigate readmission rates and factors related to readmission after surgical and nonsurgical management of odontoid fractures. SUMMARY OF BACKGROUND DATA: Management of odontoid fractures, which are the most common isolated spine fracture in the elderly, continues to be debated. The choice between surgical or nonsurgical treatment has been reported to impact mortality and might influence readmission rates. Hospital readmissions represent a large financial burden upon our healthcare system. Factors surrounding hospital readmissions would benefit from a better understanding of their associated causes to lower health care costs. METHODS: A retrospective study was performed using the 2016 Healthcare Utilization Project (HCUP) Nationwide Readmission Database (NRD). Demographic information and factors associated with readmission were collected. Readmission rates, complications, length of hospital stay were collected. Patients treated operatively, nonoperatively, and patients who were readmitted or not readmitted were compared. Statistical analysis was performed using open source software SciPy (Python v1.3.0) for all analyses. RESULTS: We identified 2921 patients who presented with Type II dens fractures from January 1, 2016 to September 30, 2016, 555 of which underwent surgical intervention. The readmission rate in patients who underwent surgery was 16.4% (91/555) and 29.4% (696/2366) in the nonoperative group. Hospital costs for readmitted and nonreadmitted patients were $353,704 and $174,922, and $197,099 and $80,715 for nonoperatively managed patients, respectively. Medicaid and Medicare patients had the highest readmission rate in both groups. Charlson and Elixhauser comorbidity indices were significantly higher in patients who were readmitted (P < 0.0001). CONCLUSION: We report an overall 90-day readmission rate of 16.4% and 29.4%, in operative and nonoperative management of type II odontoid fractures, respectively. In the face of a rising incidence of this fracture in the elderly population, an understanding of the comorbidities and age-related demographics associated with 90-day readmissions following both surgical and nonsurgical treatment are critical.Level of Evidence: 3.

De novo methicillin-resistant Staphylococcus aureus vs. methicillin-sensitive Staphylococcus aureus infections of the spine, similar clinical outcome, despite more severe presentation in surgical patients.

Vertebral osteomyelitis (VO) is a severe infection of the vertebral body and the adjacent disc space, where Staphylococcus aureus is most commonly isolated. The objective of this retrospective study was to determine risk factors for and compare outcome differences between de novo methicillin-resistant Staphylococcus aureus (MRSA) VO and methicillin-sensitive Staphylococcus aureus (MSSA) VO. A retrospective cohort study was performed by review of the electronic medical records of 4541 consecutive spine surgery patients. Among these 37 underwent surgical treatment of de novo MRSA and MSSA spinal infections. Patient demographics, pre- and postoperative neurological status (ASIA impairment score), surgical treatment, inflammatory laboratory values, nutritional status, comorbidities, antibiotics, hospital stay, ICU stay, reoperation, readmission, and complications were collected. A minimum follow-up (FU) of 12 months was required. Among the 37 patients with de novo VO, 19 were MRSA and 18 were MSSA. Mean age was 52.4 and 52.9 years in the MRSA and MSSA groups, respectively. Neurological deficits were found in 53% of patients with MRSA infection and in 17% of the patients with MSSA infection, which was statistically significant (p < 0.05). Chronic renal insufficiency and malnutrition were found to be significant risk factors for MRSA VO. Preoperative albumin was significantly lower in the MRSA group (p < 0.05). Patients suffering from spinal infection with chronic renal insufficiency and malnutrition should be watched more carefully for MRSA. The MRSA group did not show a significant difference with regard to final clinical outcome despite more severe presentation.

Extreme Lateral Interbody Fusion for Thoracic and Thoracolumbar Disease: The Diaphragm Dilemma.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: Complication profiles for lateral approaches to the spine are well established. However, the influence of level of surgery on complication rates and subtypes are less well established. To determine risk factors for complications as determined by level and surgery type in patients undergoing a lateral (retroperitoneal or retropleural approach) to the thoracolumbar spine. METHODS: All adult patients undergoing a lateral thoracolumbar fusion with or without posterior instrumentation performed at a single institution were identified. Primary outcomes assessed were presence of complication, complication subtype, and need for reoperation. The primary independent variables were spinal level (thoracic, thoracolumbar, or lumbar) and type of surgery (discectomy or corpectomy). Categorical outcomes were compared using chi-square test. Unadjusted and adjusted odds ratios for corpectomy status were calculated to determine risk of complication by level. P < .05 was considered statistically significant. RESULTS: A total of 165 patients aged 18 to 75 years were identified as having undergone a lateral fusion. Complication rates were 28.6%, 36.4%, and 11% for thoracic, thoracolumbar, and lumbar lateral approach fusions, respectively. Under univariate analysis, patients undergoing lateral approach in the thoracic spine group had significantly higher rates of postoperative complications than those in the lumbar group (P = .005). After adjusting for corpectomy status, there was no difference in complication rates. CONCLUSIONS: Lateral (retroperitoneal or retropleural) approaches to the thoracic and thoracolumbar spine may be used with complication rates comparable to well-established lumbar approaches. Extent of surgery (corpectomy vs discectomy) rather than level of surgery may represent the primary driver of complications.

Osteology of the ilium revised: illuminating the clinical relevance.

BACKGROUND: Several studies on anterior and posterior pelvic ring fixation have identified a fragile monocortical area located at the iliac wing. However, there are no current studies regarding this structure's dimensions and relation to known anatomic structures. METHODS: Eleven human ilia were dissected from 6 specimens. After debulking soft tissue, photoluminescence was used to indicate the fragile area. The size and thickness of the iliac wing were determined and mapped in relation to the anterior superior iliac spine (ASIS) and the posterior superior iliac spine (PSIS). RESULTS: This photoluminescent unicortical area measured 15.57 cm2 with a mean minimal thickness of 1.37 mm at its thinnest part. Its average diameter was 41.15 mm horizontally and 37.45 mm vertically. In all cases, it was located at the middle third of the ilium with a mean distance of 64.58 mm to the AIIS and 62.73 mm to the PSIS. Trajectory angulation above 4.5° from the PSIS lead to violation of this area. CONCLUSION: This study provides useful anatomical information regarding a thin unicortical area at the iliac wing that is relevant to anterior and posterior pelvic ring fixation and the potential complications that can arise from iatrogenic perforation of this area.

Risk Factors Associated with 90-Day Readmissions Following Occipitocervical Fusion-A Nationwide Readmissions Database Study.

BACKGROUND: Occipitocervical fusion (OCF) procedures are increasing due to an aging population and the prevalence of trauma, rheumatoid arthritis, and tumors. Reoperation rates and readmission risk factors for cervical fusions have been established, but in relation to OCF they have not been explored. This study investigates the patterns of readmissions and complications following OCF using a national database. METHODS: The 2016 U.S. Nationwide Readmissions Database was used for sample collection. Adults (>18 years) who underwent OCF were identified using the 2016 ICD-10 coding system, and we examined the readmission rates (30-day and 90-day) and reoperation rates. RESULTS: Between January and September 2016, a total of 477 patients underwent OCF; the 30-day and 90-day readmission rates were 10.4% and 22.4%, respectively. The 90-day reoperation rate related to the index surgery was 5.7%. Mean age (68.58 years) was significantly greater in the readmitted group versus nonreadmitted group (61.76 years) (P < 0.001). The readmitted group had a significantly higher Charlson Comorbidity Index and Elixhauser Comorbidity Index (5.00 and 2.41, respectively) than the nonreadmitted group (3.25 and 1.15, respectively; P < 0.001). Nonelective OCF showed a higher readmission rate (29.18%) versus elective OCF (12.23%) (P < 0.001). Medicare and Medicaid patients showed the highest rates of readmission (27.27% and 20.41%, respectively). Readmitted patients had higher total health care costs. CONCLUSIONS: Nonelective OCF was found to have a readmission rate of almost 2½× that of elective OCF. Understanding risk factors associated with OCF will help with operative planning and patient optimization.

The use of exoskeletons in the occupational context for primary, secondary, and tertiary prevention of work-related musculoskeletal complaints.

OCCUPATIONAL APPLICATIONS This guideline includes 20 recommendations and four key statements that achieved consensus or strong consensus regarding the application of exoskeletons in the workplace for the prevention of musculoskeletal complaints and diseases, the general use and implementation of exoskeletons, and recommendations for risk assessment. The guideline is intended for company physicians, occupational physicians, ergonomists, occupational safety specialists, and employers, and serves as information for all other actors in practical occupational safety. Due to the lack of evidence from the scientific literature, the recommendations and key statements are the result of expert discussions that were conducted at a consensus conference in accordance with the Regulations of the Association of the Scientific Medical Societies in Germany, moderated by an external consultant.

TECHNICAL ABSTRACT Background The prevention of work-related musculoskeletal complaints and diseases has high priority, considering the prevalence of musculoskeletal complaints and diseases and the associated high burden on health care systems, the economy, and the people affected. Purpose: This guideline provided recommendations for potential applications of exoskeletons in the workplace for the primary, secondary, and tertiary prevention of musculoskeletal complaints and diseases, general recommendations on the use and implementation of exoskeletons, and recommendations on risk assessment. Methods: A systematic literature search, a survey among exoskeleton manufacturers and companies using exoskeletons, and expert discussions formed the basis of the formulated recommendations and key statements. For reaching consensus on the recommendations and key statements, we applied the Nominal Group and Delphi Techniques under the supervision of an external, independent moderator. Results: We formulated 20 recommendations and four key statements, all of which reached consensus or strong consensus. Conclusion: No answers could be found in the current scientific literature to the central questions in this guideline about primary, secondary, and tertiary prevention. We outline five main directions for future research on exoskeletons in occupational settings. First, using exoskeletons for prevention should be investigated using randomized controlled trials. Second, the effects of exoskeletons on work-related musculoskeletal stress and strain should be investigated both in the body region intended to be supported by the exoskeleton as well as in other non-supported body regions. Third, the effects of exoskeletons should be investigated in samples varying in age, gender, and health status, as well as during different occupational activities. Fourth, a specific risk assessment tool for exoskeletons in occupational settings should be developed and implemented to meet and evaluate the applicable occupational health and safety standards. Fifth, there is a need to expand upon the very limited social science research on the impacts of exoskeletons on employee professional understanding, social role understanding, or diversity.

Functional outcome of traumatic spinopelvic instabilities treated with lumbopelvic fixation.

The aim of this study was to assess the functional outcome after lumbopelvic fixation (LPF) using the SMFA (short musculoskeletal functional assessment) score and discuss the results in the context of the existing literature. The last consecutive 50 patients who underwent a LPF from January 1st 2011 to December 31st 2014 were identified and administered the SMFA-questionnaire. Inclusion criteria were: (1) patient underwent LPF at our institution, (2) complete medical records, (3) minimum follow-up of 12 months. Out of the 50 recipients, 22 questionnaires were returned. Five questionnaires were incomplete and therefore seventeen were included for analysis. The mean age was 60.3 years (32-86 years; 9m/8f) and the follow-up averaged 26.9 months (14-48 months). Six patients (35.3%) suffered from a low-energy trauma and 11 patients (64.7%) suffered a high-energy trauma. Patients in the low-energy group were significantly older compared to patients in the high-energy group (72.2 vs. 53.8 years; p = 0.030). Five patients (29.4%) suffered from multiple injuries. Compared to patients with low-energy trauma, patients suffering from high-energy trauma showed significantly lower scores in "daily activities" (89.6 vs. 57.1; p = 0.031), "mobility" (84.7 vs. 45.5; p = 0.015) and "function" (74.9 vs. 43.4; p = 0.020). Our results suggest that patients with older age and those with concomitant injuries show a greater impairment according to the SMFA score. Even though mostly favorable functional outcomes were reported throughout the literature, patients still show some level of impairment and do not reach normative data at final follow-up.

Prevention of Wrong-level Surgery in the Thoracic Spine: Preoperative Computer Tomography Fluoroscopy-guided Percutaneous Gold Fiducial Marker Placement in 57 Patients.

STUDY DESIGN: Retrospective review. OBJECTIVE: The aim of this study was to evaluate the feasibility, safety,s and complications of computer tomography (CT) fluoroscopy-guided percutaneous transpedicular gold fiducial marker insertion to reduce incidence of wrong-level surgery in the thoracic spine. SUMMARY OF BACKGROUND DATA: Intraoperative localization of the correct thoracic level can be challenging and time-consuming, especially in obese patients and patients with anatomical variations. In the literature there are very few studies containing low numbers of patients which assessed CT or CT fluoroscopy-guided fiducial marker placement of the thoracic spine. Description of this technique has been similarly scarce. METHODS: All patients who underwent percutaneous CT fluoroscopy-guided gold fiducial marker placement of the thoracic spine were retrospectively reviewed. Indications for surgery included degenerative disc disease, infection, spinal metastasis, and intra- and extradural tumors. Gold fiducial markers were placed using a percutaneous CT fluoroscopy-guided transpedicular approach with local anesthesia. In addition, sex, age, body mass index (BMI), thoracic level, related pathology, and procedure-related complications were also recorded. RESULTS: A total of 57 patients (24 females, 33 males) were included. Mean age was 58.6 ±â€Š15.5 years. No complications during CT fluoroscopy-guided gold fiducial marker placement were recorded. Intraoperative localization was successful in all patients. Mean BMI was 32.98 kg/m (range, 18.63-56.03 kg/m), and 63% of patients were obese (>30 kg/m). T7 (n = 11) was the most often marked vertebral body, followed by T10 (n = 10) and T6 (n = 7). The most cranial and most caudal levels marked were T2 and T12, respectively. CONCLUSION: Preoperative CT fluoroscopy-guided percutaneous gold fiducial marker placement is safe, feasible, and accurate. The resulting facilitated localization of the intended thoracic level of surgery can reduce the length of surgery and prevent wrong-level surgery. Further studies are needed to evaluate in the effect on exposure to radiation and quantify the difference in operating room time. LEVEL OF EVIDENCE: 4.