Is Routine Use of External Spinal Orthoses Necessary After Operative Stabilization of Cervical Spine Injuries?

STUDY DESIGN: Retrospective Review. OBJECTIVE: The purpose of this study is to evaluate the efficacy of postoperative cervical orthoses to prevent fixation failure and loss of reduction after operative treatment of cervical spine fractures. SUMMARY OF BACKGROUND DATA: While cervical orthoses are most times tolerated in trauma patients, it is not clear that postoperative bracing is effective at reducing the rate of fixation failure or nonunion in this patient population. Cervical collars may delay rehabilitation, increase the risk of dysphagia and aspiration, and can contribute to skin breakdown. METHODS: All patients who underwent operative stabilization for cervical spine injuries at a single institution between January 2015 and August 2019 were identified through the institutional Research Electronic Data Capture (REDcap) database. Patient data, including cervical spine injury, surgery, post-operative orthosis use, and secondary surgeries for loss of reduction or infection, were recorded for all patients meeting the inclusion criteria. The primary outcome was the loss of reduction or failure of fixation, requiring revision surgery. Statistical analysis was performed using Jamovi (Version 1.1) statistical software. RESULTS: In all, 201 patients meeting inclusion and exclusion criteria were identified within the study period. Overall, 133 (66.2%) patients were treated with a cervical orthosis postoperatively and 68 (33.8%) patients were allowed to mobilize as tolerated without a cervical orthosis. Fixation failure and loss of reduction occurred in 4 (1.99%) patients. Of these 4, three patients were treated with a cervical orthosis postoperatively. There was no significant difference in the risk of instrumentation failure between patients in the postoperative orthosis and no orthosis groups ( P =0.706). CONCLUSION: The use of cervical orthoses after operative stabilization of cervical spine injuries remains controversial. There was no statistically significant difference in hardware failure or loss of fixation between patients treated in cervical orthoses postoperatively and those who were not.

Belzutifan, HIF-2α Inhibitor, and Clear Cell Renal Cell Carcinoma With Somatic Von-Hippel-Lindau Loss-of-Function Mutation.

The Von-Hippel-Lindau (VHL) gene, acting as a tumor suppressor, plays a crucial role in the tumorigenesis of clear cell renal cell carcinoma (ccRCC). Approximately 90% of individuals with advanced ccRCC exhibit somatic mutations in the VHL gene. Belzutifan, orally administered small-molecule inhibitor of hypoxia-induced factor-2α, has demonstrated promising efficacy in solid tumors associated with germline loss-of-function mutations in VHL, including ccRCC. However, its impact on cases with somatic or sporadic VHL mutations remains unclear. Here, we present 2 cases where belzutifan monotherapy was employed in patients with advanced ccRCC and somatic loss-of-function mutations in VHL. Both patients exhibited a swift and sustained response, underscoring the potential role of belzutifan as a viable option in second or subsequent lines of therapy for individuals with somatic VHL mutations. Despite both patients experiencing a pulmonary crisis with respiratory compromise, their rapid response to belzutifan further emphasizes its potential utility in cases involving pulmonary or visceral crises. This report contributes valuable insights into the treatment landscape for advanced ccRCC with somatic VHL mutations.

Use of 3-Dimensional Printing Technology in Complex Spine Surgeries.

BACKGROUND: Medical implications of 3-dimensional (3D) printing technology have evolved and are increasingly used. Surgical spine oncology involves at times complex resection using various surgical approaches and unique spinal reconstruction. As high general complication rates, including hardware failure, are reported, careful preoperative planning and optimized fixation techniques should be performed. 3D printing technology allows the improvement of preoperative planning, practice and exploration of various surgical approaches, and designing customized surgical tools and patient specific implants. OBJECTIVE: To investigate the use of 3D printing technology in complex spine surgeries. METHODS: Between 2015 and 2018, all complex spine oncological cases were evaluated and assessed for the possible benefit of use of 3D printing technology. Following high-quality imaging, a computerized integrated 3D model was created. Based on the planned procedure considering the various surgical steps, a customized 3D model was planned and printed, and in select cases a 3D custom-made implant was designed and printed in various sizes with matching trials. RESULTS: A total of 7 cases were selected for the use of a 3D printing technology. For all, a custom-made model was created. In 3 of these cases, a customized 3D-printed implant was used. Special customized intraoperative instruments were made for 2 cases, and a simulated surgical approach was performed in 5 cases. In 2 cases, pre-bent rods were made based on the model created and were used in surgery later on. CONCLUSIONS: For complex spine oncology cases, the use of 3D printing allowed better preoperative planning, simplified the operative procedure, and enabled improved reconstruction.

Acute Presentation of Cervical Myelopathy Following Manipulation Therapy.

BACKGROUND: Spinal manipulation therapy (SMT) is commonly used as an effective therapeutic modality for a range of cervical symptoms. However, in rare cases, cervical manipulation may be associated with complications. In this review we present a series of cases with cervical spine injury and myelopathy following therapeutic manipulation of the neck, and examine their clinical course and neurological outcome. We conducted a search for patients who developed neurological symptoms due to cervical spinal cord injury following neck SMT in the database of a spinal unit in a tertiary hospital between the years 2008 and 2018. Patients were assessed for the clinical course and deterioration, type of manipulation used and subsequent management. A total of four patients were identified, two men and two women, aged 32-66 years. In three patients neurological deterioration appeared after chiropractic adjustment and in one patient after tuina therapy. Three patients were managed with anterior cervical discectomy and fusion while one patient declined surgical treatment. Assessment for subjective and objective evidence of cervical myelopathy should be performed prior to cervical manipulation, and suspected myelopathic patients should be sent for further workup by a specialist familiar with cervical myelopathy (such as a neurologist, a neurosurgeon or orthopedic surgeon who specializes in spinal surgery). Nevertheless, manipulation therapy remains an important and generally safe treatment modality for a variety of cervical complaints. This review does not intend to discard the role of SMT as a significant part in the management of patients with neck related symptoms, rather it is meant to draw attention to the need for careful clinical and imaging investigation before treatment.

Surgeon's perception of margins in spinal en bloc resection surgeries: how reliable is it?

PURPOSE AND BACKGROUND: En bloc resections aim at surgically removing a tumor in a single, intact piece, fully encased by a continuous shell of healthy tissue-the "margin". Intraoperative continuous assessment of the plane of resection regarding the tumor's margins is paramount. The goal of this study was to evaluate the accuracy of experienced spinal tumor surgeons' perception of these margins. METHODS: A retrospective analysis of a prospectively collected data of 1681 patients affected by spine tumors of whom 217 en bloc resections was performed. Surgeons' intraoperative assessment was compared to the histopathological assessment. RESULTS: Most were primary-163 (42 benign and 121 malignant), metastases occurred in 54 cases. 'Wide' margins were obtained in 126 cases; 'marginal' in 60 cases, and 'intralesional' in 31 cases. Surgeons assessed clear margins in 109 cases and contaminated in 108 cases. When considering marginal margins as a contaminated resection, the surgeon's assessment of clear resection had a sensitivity of 76.89%, specificity of 86.81%, PPV and NPV (positive and negative predictive values) were 88.99 and 73.15%, respectively. Inter-observer agreement was 0.62. When considering marginal margins as a clear resection, the surgeon's assessment of clear resection had a sensitivity of 64.5%, specificity of 100%, PPV and NPV were 100 and 0%, respectively. Inter-observer agreement was 0.29. CONCLUSION: Surgeons are fairly accurate in their intraoperative assessment of clear margins achieved; however, this accuracy is not perfect and exploring ways to improve this intraoperative assessment is of major importance possibly impacting the outcome of the treatment.

Treatment of Spinal Tumors in a High Volume Center has Direct Impact on Local Recurrence, Morbidity, and Mortality.

OBJECTIVE OF THE STUDY: En bloc resections of spine tumors aim at locally controlling the disease for both improving the patient's quality of life as well as improving mortality. The purpose of this study was to compare the outcome between patients who were initially treated in a high volume specialized center, and patients who initially underwent either invasive diagnostic procedure or an initial surgical attempt to treat the disease in a different center. MATERIALS AND METHODS: A retrospective study of 1681 patients affected by spine tumors-treated from 1990 to 2015 by the same team. RESULTS: A total of 220 en bloc resections that were performed on 216 patients during that period. Most of the tumors were primary-165 cases (43 benign and 122 malignant), metastases occurred in 55 cases. One hundred sixty-eight patients (77.8%) were solely treated in the institute and were considered noncontaminated cases (NCCs) and 48 (22.2%) were previously treated elsewhere and were considered contaminated cases (CCs). Median follow-up was 45 months (0-371).Thirty-three local recurrences (15.28%) were recorded. Fourteen patients (29.17%) from the CC and 19 (11.31%) from the NCC group.A total of 153 complications were observed in 100 out of 216 patients (46.2%). Sixty-four of these patients (30%) suffered 1 complication, while the rest had 2 or more. Twenty-eight (58%) of the CC group and 72 (42.85%) of the NCC group, had at least 1 complication.Sixty patients died as a result of the disease during the follow-up period. Twenty-one (43.75%) and 39 (23.21%) patients died in the CC and NCC cohorts, respectively.CC, surgical margins of the resected tumor-intralesional, marginal, and malignant tumors, were statistically significant independent risk factors for local recurrence of the tumor. Contamination, local recurrence, neoadjuvant radiotherapy, the number of level resected, and metastatic tumors compared with primary malignant tumor, were shown to be independent risk factors for patient's death. CONCLUSIONS: It is apparent that there is a substantial added risk in performing either invasive diagnostic procedures or attempting a surgical resection of the tumor in a nonspecialized center. This risk includes both higher recurrences of the tumor as well as increased mortality. It is therefore reasonable to conclude that the whole treatment, from biopsy to resection, should be performed in the same center, and this center should be a high volume, specialized in treating these type of spine pathologies.The surgeon who treats the patient first has a great responsibility, as it is the first treatment that most affects prognosis. To reduce the chance of local recurrence, morbidity, and mortality, all invasive diagnosis and treatment, should be performed by an experienced team, as the consequences are dramatic.

A Comparison of Different Minimally Invasive and Open Posterior Spinal Procedures Using Volumetric Measurements of the Surgical Exposures.

STUDY DESIGN: A Prospective observational study. SUMMARY OF THE BACKGROUND DATA: Minimally invasive (MI) spine surgery techniques strive to minimize the damage to paraspinal soft tissues. Previous studies used only the length of the surgical incision to quantify the invasiveness of certain MI procedures. However, this method does not take into account the volume of muscle tissue that is dissected and retracted from the spine to achieve sufficient exposure. To date, no simple method has been reported to measure the volume of the surgical exposure and to quantify the degree of surgery invasiveness. STUDY OBJECTIVES: To obtain and compare volumetric measures of various MI and open posterior-approached spinal surgical exposures. METHODS: The length, the depth, and the volume of the surgical exposure were obtained from 57 patients who underwent either open or MI posterior lumbar surgery. MI procedures included the following: tubular discectomy, laminotomy, and transforaminal interbody fusion. Open procedures included the following: discectomy, laminectomy, transforaminal interbody fusion, or posterior-lateral instrumented fusion. Four attending spine surgeons at our unit performed the surgeries. To reduce variability, only single-level procedures performed between L4 and S1 vertebrae were used. The volume of exposure was obtained by measuring the amount of saline needed to fill the surgical wound completely once the surgical retractors were deployed and opened. RESULTS: The average volumes in mililiters of exposure for a single-level MI procedure ranged from 9.8±2.8 to 75±11.7 mL and were significantly smaller than the average volumes of exposure for a single level open procedures that ranged from 44± 21 to 277±47.9 P<0.001. The average skin-incision lengths for single-level MI procedures ranged from 1.7±0.2 to 7.7±1.6 cm and were significantly smaller than the average skin-incision lengths for open procedures [5.2±1.4 (Table 3) to 11.3±2 cm, P<0.001]. The measured surgical depths were similar in MI and open groups (P=0.138). MI decompression and posterior fusion procedures yielded 92% and 73% reductions in the volumes of exposure, respectively. However, absolute differences in exposure volumes were larger for fusion (202 mL) compared with decompression alone (110.7 mL). CONCLUSIONS: Direct volumetric measurement of the surgical exposure is obtained easily by measuring the amount of saline needed to fill the exposed cavity. Using this method, the needed surgical exposure of different spinal procedures can be quantified and compared. This volumetric measurement combined with the measure of retraction force, the duration of retraction, and the impact on soft tissue vascularity can help build a model that assesses the relative invasiveness of different spinal procedures.

En Bloc Resections in the Spine: The Experience of 220 Patients During 25 Years.

BACKGROUND AND OBJECTIVE: En bloc resections aim at surgically removing a tumor in a single, intact piece. Approach must be planned for the complete removal of the tumor without violation of its margins. The shared knowledge of the morbidity, mortality, risk assessment for local disease recurrence, complications, and death, related to spine tumors excised en bloc could improve the treating physician's apprehension of the diseases and decision making process before, during, and after surgical treatment. The purpose of this study was to review and report the experience gained during 25 years in one of the world's biggest spine oncologic centers. METHODS: A retrospective study of prospective collected data of 1681 patients affected by spine tumors, of whom 220 had en bloc resections performed. RESULTS: Most tumors were primary-165 cases (43 benign and 122 malignant); metastases occurred in 55 patients. A total of 60 patients died from the disease and 33 local recurrences were recorded. A total of 153 complications were observed in 100 of 216 patients (46.2%); 64 of these patients (30%) suffered 1 complication, whereas the rest had 2 or more. All complications were categorized according to temporal distribution and severity. These were further divided into 7 groups according to the type of complication. There were 105 major and 48 minor complications. Seven patients (4.6%) died as a result of complications. There were 33 local recurrences (15.28%) recorded. Contaminated cases, surgical margins of the resected tumor-intralesional, marginal, and malignant tumors-were statistically significant independent risk factors for local recurrence of the tumor. Contamination, local recurrence, neoadjuvant radiotherapy, number of levels resected, and metastatic tumors compared with primary malignant tumor were shown to be independent risk factors for a patient's death. CONCLUSIONS: Treatment of spinal aggressive benign and malignant bone tumors with en bloc resection is beneficial in terms of better local control and prognosis, although it is a highly demanding and risky procedure. Margins are the key point of this procedure, thus a careful preoperative oncologic and surgical staging is necessary to define the optimal surgical approach. The adverse event profile of these surgeries is high. Therefore, it should be performed by experienced and multidisciplinary teams in specialized high volume centers.

Predictors for surgical complications of en bloc resections in the spine: review of 220 cases treated by the same team.

PURPOSE: Identify risk factors, enabling reduction of the rate of complications and improve outcome in en bloc resection surgeries. METHODS: A retrospective study of prospective collected data of 1681 patients affected by spine tumors treated from 1990 to 2015 by the same team. RESULTS: A total of 220 en bloc resections that were performed on 216 patients during that period. Most of the tumors were primary-165 cases (43 benign and 122 malignant), metastases occurred in 55 cases. Median FU was 45 months (0-371). 153 complications were observed in 100 patients (46.2 %). 64 (30 %) suffered one complication, while the rest had two or more. There were 105 major and 48 minor complications. Seven patients (4.6 %) died as a result of complications. The combined approach, neoadjuvant chemotherapy and neoadjuvant radiotherapy were statistically significant independent risk factors for complications occurrence. 33 patients (15.2 %) suffered from local recurrence. Reoperations were mostly due to tumor recurrences, but also to hardware failures, wound dehiscence, hematomas and aortic dissection. CONCLUSION: The rate of complication is higher in multisegmental resections and when double combined approach is performed. Reoperations display greater morbidity owing to dissection through scar/fibrosis from previous operations and possibly from RT. Careful treatment planning and, in the event of uncertainty, referral to a specialty center must be stressed. The high risk of complications should not discourage surgeons from performing en bloc resection when needed. Most of the patients who sustain complications benefit from the better local control resulting from en bloc resection.

Minimally Invasive Spinal Decompression in Patients Older Than 75 Years of Age: Perioperative Risks, Complications, and Clinical Outcomes Compared with Patients Younger Than 45 Years of Age.

OBJECTIVE: Minimally invasive spinal decompression for the treatment of spinal stenosis or disk herniation is often indicated if conservative management fails. However, the influence of old age on the risk of postoperative complications and clinical outcome is not well understood. We therefore sought to compare complication rates and outcomes after minimally invasive surgery decompression and discectomy in elderly patients with a cohort of younger patients undergoing similar procedures. METHODS: We evaluated medical records of 61 patients older than 75 years and 69 patients younger than 45 years that underwent minimally invasive lumbar decompression between April 2009 and July 2013 at our institute. Medical history, American Society of Anesthesiologists score, perioperative mortality, complications, and revision surgery rates were analyzed. Patient outcomes included visual analog scale and EuroQol-5 Dimension scores. RESULTS: The average age was 78.66 ± 4.42 years in the elderly group and 33.59 ± 6.7 years in the younger group. No major postoperative complications were recorded in either group, and all recruited patients were still alive at the time of the last follow-up. No statistically significant difference existed in the surgical revision rate between the groups. Both groups showed significant improvement in their outcome scores after surgery. CONCLUSIONS: Our results indicate that minimally invasive decompressive surgery is a safe and effective treatment for elderly patients and does not pose an increased risk of complications. Future prospective studies are necessary to validate the specific advantages of the minimally invasive techniques in the elderly population.

The correlation between radiographic knee OA and clinical symptoms--do we know everything?

UNLABELLED: This study aims to evaluate the correlations between common clinical osteoarthritis (OA) diagnostic tools in order to determine the value of each. A secondary goal was to investigate the influence of gender differences on the findings. Five hundred and eighteen patients with knee OA were evaluated using the Western Ontario and McMaster Osteoarthritis Index (WOMAC) questionnaire, short form 36 (SF-36) Health Survey, and plain radiographs. Analysis of variance (ANOVA) was used to compare the different domains of the WOMAC and SF-36 questionnaires between genders and the radiographic scale. Higher knee OA x-ray grade were associated with worse clinical outcome: for women, higher scores for the WOMAC pain, function and final scores and lower scores in the SF-36 final score; in men, lower SF-36 overall and physical domains scores. Gender differences were found in all clinical scores that were tested, with women having worse clinical scores for similar radiographic grading (p values <0.001). Knee radiographs for OA have an important role in the clinical evaluation of the patient. Patients with higher levels of knee OA in x-ray have a higher probability of having a worse clinical score in the WOMAC and SF-36 scores. The gender differences suggest that for similar knee OA x-ray grade, women's clinical scores are lower. TRIAL REGISTRATION: NCT00767780.

Surgical approach and prosthesis fixation in hip arthroplasty world wide.

BACKGROUND: Hip arthroplasty is one of the most common and successful surgical procedures worldwide. Component design and materials as well as surgical techniques constantly evolve. There is no consensus among surgeons regarding the ideal surgical approach and method of fixation. MATERIALS AND METHODS: 292 orthopedic surgeons of 10 subspecialties from 57 countries were surveyed on their choice of surgical approach and prosthesis fixation in hip arthroplasty. Their preferences were analyzed according to country of origin, field of expertise and seniority, and compared to current publications. RESULTS: The response rate was 95-98 %. Surgeons were split between the posterior approach (45 %) and the direct lateral approach (42 %) followed by the anterior approach (10 %) or other (3 %). North American surgeons favored the posterior approach more often than Europeans (69 % compared to 36 %, P < 0.0001) and surgeons from other countries (69 % compared to 45 %, P = 0.01). Sixty-eight percent of all surgeons routinely used noncemented hip prosthesis while 16 % use cemented and 16 % hybrid fixation. Noncemented fixation was preferred among surgeons from Europe and North America compared to other countries (73 % compared to 55 %, P < 0.05). There were no significant differences based on subspecialty, seniority or the number of years of experience. CONCLUSIONS: The most common surgical approaches in use in hip arthroplasty are posterior and lateral. Anterior approach is used by a minority of orthopedic surgeons for that purpose. Cementing hip prosthesis is falling out of favor among orthopedic surgeons worldwide. The trend toward un-cemented hip arthroplasty is not well supported in the current literature.

An international survey on anterior cruciate ligament reconstruction practices.

PURPOSE: Bone-patellar-tendon-bone (BPTB) autografting fixed with metal interference screws (IS) is the gold standard for anterior cruciate ligament (ACL) reconstruction. Advances in surgical technology provide a wide choice of grafts, fixation devices and surgical approaches. METHODS: Two-hundred and sixty-one orthopedic surgeons of ten subspecialties from 57 countries were surveyed on their choice of graft and fixation device, the number of reconstructed bundles, and arthroscopic portal. Their preferences were analyzed according to country of origin, field of expertise and seniority, and compared to current publications. RESULTS: Hamstring autografting was the most popular choice (63 %), then BPTB (26 %) and allograft (11 %). The anteromedial portal was preferred over the traditional transtibial portal (68 % versus 31 %). Two-thirds reported routinely performing a single-bundle graft reconstruction, compared to one-third who used the double-bundle technique. The Endo-button was the most common graft fixation method (40 %), followed by the bioabsorbable IS (34 %), metallic IS (12 %), rigidfix (10 %) and others (4 %). The preferences of hamstring tendon grafting and the anteromedial portal are not supported in the literature. Responses from North American and European surgeons were different from all the others. CONCLUSIONS: Surgeon preferences in ACL reconstruction differ considerably worldwide. Common practice is not always supported by evidence-based publications.

A cadaver study to compare vertebral augmentation with a high-viscosity cement to augmentation with conventional lower-viscosity cement.

STUDY DESIGN: Comparison of extravasations in fractured cadaver vertebrae augmented with commercial low-viscosity versus high-viscosity cements. OBJECTIVE: Use of high-resolution, 3-dimensional (3D) imaging to test the hypothesis that high-viscosity cements can reduce the type and severity of extravasations after vertebral augmentation procedures. SUMMARY OF BACKGROUND DATA: Cement extravasations are one of the primary complications of vertebral augmentation procedures. There is some evidence that high-viscosity cements might reduce extravasations, but additional data are needed to confirm the early findings. METHODS: A range of vertebral fractures were created in fresh human cadavers. One group was then augmented with a low-viscosity polymethylmethacrylate (PMMA)-based cement and the other group injected with high-viscosity PMMA-based cement. High-resolution computerized tomography exams were obtained, and extravasations were assessed using 3D volume renderings. The type and severity of extravasations were recorded and analyzed. RESULTS: The proportion of vertebrae with any type of extravasation through the posterior wall to the spinal canal, into small vessels laterally or anteriorly, through the endplates, or anywhere around the body was not significantly different between the high-viscosity and low-viscosity groups. There was significantly less severe extravasation through the endplates (P=0.02), and a trend toward less severe extravasation through vessels (P=0.06) with the high versus low-viscosity cements. CONCLUSIONS: In agreement with previous research, high-viscosity PMMA-based cement may help to reduce the more severe forms of extravasations after vertebral augmentation procedures in newly fractured vertebrae.

Anti-platelet therapy: no association with increased blood loss in patients undergoing open or laparoscopic appendectomy.

BACKGROUND: The effect of anti-platelet drugs on surgical blood loss and perioperative complications has not been studied in depth and the management of surgical patients taking anti-platelet medications is controversial. OBJECTIVE: To assess the effect of anti-platelet therapy on perioperative blood loss in patients undergoing appendectomy either laparoscopically or via open surgery. METHODS: We reviewed the files of all patients 40 years old who underwent open or laparoscopic appendectomies from 2007 to 2010. Excluded were patients with short hospitalization and no follow-up of hemoglobin level, patients on warfarin treatment and patients who underwent additional procedures. Estimation of blood loss was based on decrease in hemoglobin level from admission to discharge. Risk factors for blood loss, such as anti-platelet therapy, age, gender, surgical approach, surgical time, surgical findings and complications, were analyzed. RESULTS: The final cohort included 179 patients (mean age 61 +/- 14 years, range 40-93) of whom 65 were males. The mean perioperative hemoglobin decrease was 1.59 +/- 1.07 mg/dl (range 0-5 mg/dl). Thirty-nine patients received anti-platelet therapy prior to surgery and 140 did not. No significant differences in decrease of hemoglobin level were found between patients receiving anti-platelet therapy and those who were not (1.73 +/- 1.21 vs. 1.55 +/- 1.02 mg/dl, P = 0.3). In addition, no difference was found between patients on anti-platelettherapy operated laparoscopically and those operated in an open fashion (1.59 +/- 1.18 vs. 2.04 +/- 1.28 mg/ dl, P = 0.29). Five patients required blood transfusions, two of whom were on anti-platelet therapy. Blood loss was significantly greater in patients with a perforated appendicitis and in those with an operative time of more than one hour. CONCLUSIONS: Anti-platelet therapy does not pose a risk for increased blood loss following emergent appendectomy performed either laparoscopically or in an open fashion.

Reference data for interpreting widening between spinous processes in the lumbar spine.

BACKGROUND CONTEXT: Traumatic injury to the lumbar spine is evaluated and treated based on the perceived stability of the spine. Recent classification schemes have established the importance of evaluating the posterior ligamentous complex (PLC) to fully comprehend stability. There are a variety of techniques to evaluate the PLC, including assessment of interspinous distance. However reference data to define normal widening are poorly developed. PURPOSE: Define normal interspinous widening in the lumbar spine. STUDY DESIGN: Biomechanical and observational. To establish reference data for asymptomatic population and use the reference data to suggest criteria for routine clinical practice to be validated in future studies. METHODS: Interspinous distances were measured from lateral lumbar X-rays of 157 asymptomatic volunteers. Measurements from the asymptomatic population were used to define normal limits and create a simple screening tool for clinical use. Distances were calculated from the relative position of landmarks at each intervertebral level. The distances were normalized to the anterior-posterior width of the superior end plate of L3. The change in interspinous process distance from flexion to extension was calculated, and the change in interspinous widening between flexion and extension with respect to widening at the adjacent levels was also calculated. RESULTS: Seven hundred seventy-two thoracolumbar levels were available for analysis. The observed interspinous motion was slightly more than the interlaminar motion. However, the tips of the spinous processes were more difficult to identify in some images, so the interlaminar line distances were considered more reliable. Significant difference in interlaminar distances was not found between levels. The upper limit (UL) of normal spacing measured between the interlaminar lines was approximately 85% of the L3 end plate width at all levels except L5-S1, which was 105%. The UL of normal for interlaminar displacements between flexion and extension was 30% of the L3 end plate width at L1-L2 to L4-L5 and 40% at L5-S1. CONCLUSIONS: This study provides normative data and methods that can be used in developing guidelines to objectively assess interspinous process widening. Simple rules can be applied to quickly assess interspinous widening. Additional research is required to validate these guidelines. A simple measurement such as spinous process widening is unlikely to be proven as an isolated clinically effective screening test but combining that with other patient evaluation's screening modalities may prove to be a sensitive evaluation protocol for the screening of injuries to the PLC.

Motion within the unstable cervical spine during patient maneuvering: the neck pivot-shift phenomenon.

BACKGROUND: Cervical extrication collars are applied to millions of blunt trauma victims despite the lack of any evidence that a collar can protect against secondary injuries to the cervical spine. Cadaver studies support that in the presence of a dissociative injury, substantial motion can occur within the occipitocervical spine with collar application or during patient transfers. Little is known about the biomechanics of cervical stabilization; hence, it is difficult to develop and test improved immobilization strategies. MATERIALS: Severe unstable injuries were created in seven fresh whole human cadavers. Rigid collars were applied with the body in a neutral position. Computed tomographic examinations were obtained before and after tilting the body or backboard as would be done during patient transport or to inspect the back. Relative displacements between vertebrae at the site of the injury were measured from the Computed tomographic examinations. The overall relative alignment between body and collar was assessed to understand the mechanisms that may facilitate motion at the injury site. RESULTS: Intervertebral motion averaged 7.7 mm±6.8 mm in the axial plain and 2.9 mm±2.5 mm in the cranial-caudal direction. The rigid collars appeared to create pivot points where the collar contacts the head in the region under the ear and where the collar contacts the shoulders. DISCUSSION: Rigid cervical collars appear to create pivot points that shift the center of rotation lateral to the spine and contribute to the intervertebral motions that were measured. Immobilization strategies that avoid these neck pivot-shift phenomena may help to reduce secondary injuries to the cervical spine. The whole cadaver model with simulation of patient maneuvers may provide an effective test method for cervical immobilization.

A pictorial classification atlas of cement extravasation with vertebral augmentation.

BACKGROUND CONTEXT: Minimally invasive procedures for the treatment of vertebral compression fractures (VCFs) have been in use since the mid-1980s. A mixture of liquid monomer and powder is introduced through a needle into one or both pedicles, and it polymerizes within the vertebral body in an exothermic chemical reaction. The interaction between cement and the fractured vertebral body determines whether and how the cement stabilizes the fragments, alters morphology, and extravasates. The cement is intended to remain within the vertebral body. However, some studies have reported cement leakage in more than 80% of the procedures. Although cement leakage can have no or minimal clinical consequences, adverse events, such as paraplegia, spinal cord and nerve root compression, cement pulmonary embolisms, or death, can occur. The details of how the cement infiltrates a vertebral body or extravasates out of the body are poorly understood and may help to identify strategies to reduce complications and improve clinical efficacy. PURPOSE: Apply novel techniques to demonstrate the cement spread inside vertebrae as well as the points and pattern of cement extravastation. STUDY DESIGN: Ex vivo assessment of vertebral augmentation procedures. METHODS: Vertebrae from six fresh whole human cadaver spines were used to create 24 specimens of three vertebrae each. The specimens were placed in a pneumatic testing system, designed to create controlled anterior wedge compression fractures. Unipedicular augmentation was performed on the central vertebra of 24 specimens using polymethylmethacrylate/barium sulfate Vertebroplastic cements (DePuy Spine, Raynham, MA, USA). The volume of cement injected into each vertebra was recorded. Fine-cut computed tomography (CT) scans of all segments were obtained (Brilliance 64; Philips Medical Imaging, Amsterdam, The Netherlands). Using multiplanar reconstructions and volume compositing three-dimensional imaging (Osirix, www.osirix-viewer.com), each specimen was carefully assessed for cement extravasation. Specimens were then immersed in a 50% sodium hypochlorite solution until all overlying soft tissues were removed, leaving the bone and cement intact. The specimens were dried and visually examined and photographed to assess cement extravasation and fracture patterns. Specimens were cut in the axial or sagittal plains to assess the gross morphology of cement infiltration and extravasation. Finally, 25-mm block sections were removed from selected specimens and imaged at 14-µm resolution using a GE Locus-SP micro-CT system (GE Healthcare, London, Ontario, Canada). RESULTS: Infiltration was characterized by an intimate capture of trabecular bone within the cement, forming an irregular border at the perimeter of the cement that is determined by the morphology of the trabeculae and marrow spaces. Extravasation of the cement was assessed as "any" if any small or large amount of extravastation was detected and was also assessed as severe if a large amount of extravasation was found. Out of the 23 levels studied, some extravasation was visibly apparent in all levels. A wide spectrum of filling patterns, leakage points, and interdigitation of the cement was observed and appeared to be determined by the interaction of the cement with the trabecular morphology. The results support the fact that the cement generally advances through the vertebrae with relatively regular and easily identifiable borders. CONCLUSIONS: Using a cadaver VCF model, this study demonstrated the exact filling and extravastation patterns of bone cement inside and out of fractured vertebrae. These data enhance our understanding of the vertebral augmentation and extravastation mechanics.

The association of occipitocervical dissociation and death as a result of blunt trauma.

BACKGROUND CONTEXT: Despite multiple reports of survivability, dissociative occipitocervical injury (OCI) is generally accepted to be fatal in most cases. The actual number of trauma victims where OCI may have made the difference between life and death is unknown because multiple studies have shown that these injuries can be missed with current diagnostic methods. An improved understanding of the relative importance of OCI in blunt trauma mortality may help to refine protocols for the assessment and treatment of patients who arrive alive to the emergency room after severe blunt trauma. One way to improve our understanding is to document the relative frequency OCI relative to brain, liver, aorta, and spleen injuries in blunt trauma fatalities. PURPOSE: In this study, we aimed to glean a more accurate estimate of the absolute and relative incidence of OCI after death from blunt trauma via a systematic review of data reported in the forensic literature. STUDY DESIGN: Systematic literature review. METHODS: A systematic literature search and review were undertaken. The search aimed to answer three primary questions: What is the true incidence of cervical spine injuries in blunt trauma fatalities? What is the incidence of dissociative OCIs specifically? and What is the incidence of these injuries relative to other common injuries associated with blunt trauma fatalities (central nervous system, spleen, liver, etc)? For that, two search protocols were used and included postmortem studies of blunt trauma mechanism in adult population. RESULTS: The mean reported incidence of cervical spine injuries was 49.7% in blunt trauma fatalities. Dissociative OCIs were found to have a mean incidence of 18.1%. The relative frequencies of injuries were 49.7% for cervical spine, 41.8% for central nervous system, 20.8% for liver, 11.2% for spleen, and 10.8% for aorta. CONCLUSIONS: In this systematic literature review, cervical spine injuries were found to be the most commonly reported finding associated with blunt trauma fatalities, occurring in nearly 50% of cases with occipitocervical dissociation accounting for nearly 20%. Older pathologic studies suggested a lesser overall and relative frequency and may have underestimated their incidence. Typically, these blunt cervical spine injuries were much more commonly found to disrupt the soft tissue stabilizing restraints (ligaments, facet capsules, etc) as opposed to causing bony fractures and, accordingly, were often not detected on plain radiographs. It is likely that the frequency of this injury is underestimated in patients surviving severe blunt trauma, placing them at risk for death from an occult source in the postinjury period. Additional research is needed to determine if improved methods to diagnose OCI and improved patient management protocols to protect against secondary injuries might reduce mortality in blunt trauma victims.

Occipitocervical dissociative injuries: common in blunt trauma fatalities and better detected with objective computed tomography-based measurements.

BACKGROUND CONTEXT: Occipitocervical injuries (OCIs) are generally not common in blunt trauma victims, but autopsy studies of blunt trauma fatalities consistently report a high prevalence of these injuries. New computed tomography (CT)-based quantitative criteria have recently been developed for use in assessing the occipitocervical spine. The efficacy of these new criteria for detecting OCI would be supported if the high prevalence of OCI in blunt trauma fatalities can also be detected using these objective CT-based criteria. PURPOSE: To test the hypothesis that the prevalence of OCI in blunt trauma fatalities, determined using objective CT-based measurements and reliable reference data, will be similar to the prevalence reported in prior autopsy studies. STUDY DESIGN/SETTING: Retrospective assessment of the CT examinations of blunt trauma fatalities at a Level 1 trauma center. PATIENT SAMPLE: Seventy-four consecutive patients who died within 21 days of blunt trauma and had a CT examination of the cervical spine. OUTCOME MEASURES: Quantitative measurements from CT examinations of the occiput-C1 and C1-C2 levels. METHODS: Measurements were made on a Picture Archiving and Communication System (PACS) from the CT images that were originally used for diagnosis and also using imaging software that allowed for precisely reoriented slices that correct for variations in the alignment of the upper cervical spine. The prevalence of abnormal measurements found by each method and the interobserver reliability of the measurements were assessed. RESULTS: At least one abnormal measurement was found in 50% of cases based on measurements made on the PACS, and in 34% of cases using measurements from carefully reoriented images. At least three abnormal measurements were found in 22% and 14% of patients, respectively. Only one of the patients had been diagnosed as having an OCI before death. Interobserver reliability measurements of more than 80% were found for most measurements. CONCLUSIONS: Using precise CT-based measurements and reliable reference data for diagnosis of occipitocervical dissociative injuries, the prevalence of injuries in severely injured blunt trauma patients was close to the levels reported in prior autopsy studies (approximately 30%). This supports that with careful measurements, both soft- and hard-tissue OCI can be detected by CT. This study is limited by the fact that a gold standard was not available to confirm the injuries.