Percutaneous Cementation for Improvement of Pain and Function for Osteolytic Pelvic Metastasis: A Systematic Review

INTRODUCTION

Pelvic metastasis is a common presentation among patients presenting with skeletal metastasis. Image-guided percutaneous cementation of these lesions is becoming increasingly popular for the treatment of these lesions. The objective of this study was to conduct a systematic review that investigates clinical outcomes after percutaneous cementation for pelvic metastasis.

METHODS

A systematic review was registered with International Prospective Register of Systematic Reviews and performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines using the PubMed, SCOPUS, and Ovid MEDLINE databases. All level I to IV clinical studies published in the English language investigating the clinical outcomes after percutaneous cementation for pelvic metastasis were included.

RESULTS

Fourteen studies with 579 patients (278 men, 301 women) and 631 metastatic pelvic lesions were included in the study. The mean follow-up range was 0.7 to 26.4 months. Percutaneous cementation alone was performed in 441 patients (76.2%). Supplemental ablative procedures were performed in 77 patients (13.3%), and supplemental internal fixation using cannulated screws was performed in 107 patients (18.5%). Twelve studies with 430 patients (74.2%) reported pain-related and/or functional outcome scores, of which all studies reported overall clinically notable improvement at short-term follow-up. All studies reported periprocedural complications. Local cement leakage was the most common complication (162/631 lesions, 25.7%) followed by transient local pain (25/579 patients, 4.3%). There were no reported cases of major complications. Seven patients (1.2%) underwent re-intervention for persistent symptoms.

CONCLUSIONS

Percutaneous cementation may be an effective method for treating pain and function related to pelvic metastasis. The most common complication was cement leakage surrounding the lesion. The rates of major complications were low, and most complications appeared minor and transient. Additional prospective studies are needed to further assess the efficacy of this procedure.

LEVEL OF EVIDENCE

IV, systematic review of level I to IV therapeutic studies.

Response to Letter Regarding "Predictive Value of Preoperative Serum Albumin in Patients With Metastatic Spine Diseases: A Statistical Comment"

We thank the authors for their interest in and commentary on "Preoperative Serum Albumin Level Predicts Length of Stay and Perioperative Adverse Events Following Vertebral Corpectomy and Posterior Stabilization for Metastatic Spine Disease." We appreciate the opportunity to respond to their comments herein.

The Management of Intraoperative Spinal Cord Injury - A Scoping Review

STUDY DESIGN

Scoping Review.

OBJECTIVE

To review the literature and summarize information on checklists and algorithms for responding to intraoperative neuromonitoring (IONM) alerts and management of intraoperative spinal cord injuries (ISCIs).

METHODS

MEDLINE® was searched from inception through January 26, 2022 as were sources of grey literature. We attempted to obtain guidelines and/or consensus statements from the following sources: American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM), American Academy of Neurology (AAN), American Clinical Neurophysiology Society, NASS (North American Spine Society), and other spine surgery organizations.

RESULTS

Of 16 studies reporting on management strategies for ISCIs, two were publications of consensus meetings which were conducted according to the Delphi method and eight were retrospective cohort studies. The remaining six studies were narrative reviews that proposed intraoperative checklists and management strategies for IONM alerts. Of note, 56% of included studies focused only on patients undergoing spinal deformity surgery. Intraoperative considerations and measures taken in the event of an ISCI are divided and reported in three categories of i) Anesthesiologic, ii) Neurophysiological/Technical, and iii) Surgical management strategies.

CONCLUSION

There is a paucity of literature on comparative effectiveness and harms of management strategies in response to an IONM alert and possible ISCI. There is a pressing need to develop a standardized checklist and care pathway to avoid and minimize the risk of postoperative neurologic sequelae.

A Clinical Practice Guideline for the Management of Patients With Acute Spinal Cord Injury: Recommendations on Hemodynamic Management

STUDY DESIGN

Clinical practice guideline development following the GRADE process.

OBJECTIVES

Hemodynamic management is one of the only available treatment options that likely improves neurologic outcomes in patients with acute traumatic spinal cord injury (SCI). Augmenting mean arterial pressure (MAP) aims to improve blood perfusion and oxygen delivery to the injured spinal cord in order to minimize secondary ischemic damage to neural tissue. The objective of this guideline was to update the 2013 AANS/CNS recommendations on the hemodynamic management of patients with acute traumatic SCI, acknowledging that much has been published in this area since its publication. Specifically, we sought to make recommendations on 1. The range of mean arterial pressure (MAP) to be maintained by identifying an upper and lower MAP limit; 2. The duration of such MAP augmentation; and 3. The choice of vasopressor. Additionally, we sought to make a recommendation on spinal cord perfusion pressure (SCPP) targets.

METHODS

A multidisciplinary guideline development group (GDG) was formed that included health care professionals from a wide range of clinical specialities, patient advocates, and individuals living with SCI. The GDG reviewed the 2013 AANS/CNS guidelines and voted on whether each recommendation should be endorsed or updated. A systematic review of the literature, following PRISMA standards and registered in PROSPERO, was conducted to inform the guideline development process and address the following key questions: (i) what are the effects of goal-directed interventions to optimize spinal cord perfusion on extent of neurological recovery and rates of adverse events at any time point of follow-up? and (ii) what are the effects of particular monitoring techniques, perfusion ranges, pharmacological agents, and durations of treatment on extent of neurological recovery and rates of adverse events at any time point of follow-up? The GDG combined the information from this systematic review with their clinical expertise in order to develop recommendations on a MAP target range (specifically an upper and lower limit to target), the optimal duration for MAP augmentation, and the use of vasopressors or inotropes. Using methods outlined by the GRADE working group, recommendations were formulated that considered the balance of benefits and harms, financial impact, acceptability, feasibility and patient preferences.

RESULTS

The GDG suggested that MAP should be augmented to at least 75-80 mmHg as the "lower limit," but not actively augmented beyond an "upper limit" of 90-95 mmHg in order to optimize spinal cord perfusion in acute traumatic SCI. The quality of the evidence around the "target MAP" was very low, and thus the strength of this recommendation is weak. For duration of hemodynamic management, the GDG "suggested" that MAP be augmented for a duration of 3-7 days. Again, the quality of the evidence around the duration of MAP support was very low, and thus the strength of this recommendation is also weak. The GDG felt that a recommendation on the choice of vasopressor or the use of SCPP targets was not warranted, given the dearth of available evidence.

CONCLUSION

We provide new recommendations for blood pressure management after acute SCI that acknowledge the limitations of the current evidence on the relationship between MAP and neurologic recovery. It was felt that the low quality of existing evidence and uncertainty around the relationship between MAP and neurologic recovery justified a greater range of MAP to target, and for a broader range of days post-injury than recommended in previous guidelines. While important knowledge gaps still remain regarding hemodynamic management, these recommendations represent current perspectives on the role of MAP augmentation for acute SCI.

An Update of a Clinical Practice Guideline for the Management of Patients With Acute Spinal Cord Injury: Recommendations on the Role and Timing of Decompressive Surgery

STUDY DESIGN

Clinical practice guideline development.

OBJECTIVES

Acute spinal cord injury (SCI) can result in devastating motor, sensory, and autonomic impairment; loss of independence; and reduced quality of life. Preclinical evidence suggests that early decompression of the spinal cord may help to limit secondary injury, reduce damage to the neural tissue, and improve functional outcomes. Emerging evidence indicates that "early" surgical decompression completed within 24 hours of injury also improves neurological recovery in patients with acute SCI. The objective of this clinical practice guideline (CPG) is to update the 2017 recommendations on the timing of surgical decompression and to evaluate the evidence with respect to ultra-early surgery (in particular, but not limited to, <12 hours after acute SCI).

METHODS

A multidisciplinary, international, guideline development group (GDG) was formed that consisted of spine surgeons, neurologists, critical care specialists, emergency medicine doctors, physical medicine and rehabilitation professionals, as well as individuals living with SCI. A systematic review was conducted based on accepted methodological standards to evaluate the impact of early (within 24 hours of acute SCI) or ultra-early (in particular, but not limited to, within 12 hours of acute SCI) surgery on neurological recovery, functional outcomes, administrative outcomes, safety, and cost-effectiveness. The GRADE approach was used to rate the overall strength of evidence across studies for each primary outcome. Using the "evidence-to-recommendation" framework, recommendations were then developed that considered the balance of benefits and harms, financial impact, patient values, acceptability, and feasibility. The guideline was internally appraised using the Appraisal of Guidelines for Research and Evaluation (AGREE) II tool.

RESULTS

The GDG recommended that early surgery (≤24 hours after injury) be offered as the preferred option for adult patients with acute SCI regardless of level. This recommendation was based on moderate evidence suggesting that patients were 2 times more likely to recover by ≥ 2 ASIA Impairment Score (AIS) grades at 6 months (RR: 2.76, 95% CI 1.60 to 4.98) and 12 months (RR: 1.95, 95% CI 1.26 to 3.18) if they were decompressed within 24 hours compared to after 24 hours. Furthermore, patients undergoing early surgery improved by an additional 4.50 (95% 1.70 to 7.29) points on the ASIA Motor Score compared to patients undergoing surgery after 24 hours post-injury. The GDG also agreed that a recommendation for ultra-early surgery could not be made on the basis of the current evidence because of the small sample sizes, variable definitions of what constituted ultra-early in the literature, and the inconsistency of the evidence.

CONCLUSIONS

It is recommended that patients with an acute SCI, regardless of level, undergo surgery within 24 hours after injury when medically feasible. Future research is required to determine the differential effectiveness of early surgery in different subpopulations and the impact of ultra-early surgery on neurological recovery. Moreover, further work is required to define what constitutes effective spinal cord decompression and to individualize care. It is also recognized that a concerted international effort will be required to translate these recommendations into policy.

A Clinical Practice Guideline for Prevention, Diagnosis and Management of Intraoperative Spinal Cord Injury: Recommendations for Use of Intraoperative Neuromonitoring and for the Use of Preoperative and Intraoperative Protocols for Patients Undergoing Spine Surgery

STUDY DESIGN

Development of a clinical practice guideline following the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) process.

OBJECTIVE

The objectives of this study were to develop guidelines that outline the utility of intraoperative neuromonitoring (IONM) to detect intraoperative spinal cord injury (ISCI) among patients undergoing spine surgery, to define a subset of patients undergoing spine surgery at higher risk for ISCI and to develop protocols to prevent, diagnose, and manage ISCI.

METHODS

All systematic reviews were performed according to PRISMA standards and registered on PROSPERO. A multidisciplinary, international Guidelines Development Group (GDG) reviewed and discussed the evidence using GRADE protocols. Consensus was defined by 80% agreement among GDG members. A systematic review and diagnostic test accuracy (DTA) meta-analysis was performed to synthesize pooled evidence on the diagnostic accuracy of IONM to detect ISCI among patients undergoing spinal surgery. The IONM modalities evaluated included somatosensory evoked potentials (SSEPs), motor evoked potentials (MEPs), electromyography (EMG), and multimodal neuromonitoring. Utilizing this knowledge and their clinical experience, the multidisciplinary GDG created recommendations for the use of IONM to identify ISCI in patients undergoing spine surgery. The evidence related to existing care pathways to manage ISCI was summarized and based on this a novel AO Spine-PRAXIS care pathway was created.

RESULTS

Our recommendations are as follows: (1) We recommend that intraoperative neurophysiological monitoring be employed for high risk patients undergoing spine surgery, and (2) We suggest that patients at "high risk" for ISCI during spine surgery be proactively identified, that after identification of such patients, multi-disciplinary team discussions be undertaken to manage patients, and that an intraoperative protocol including the use of IONM be implemented. A care pathway for the prevention, diagnosis, and management of ISCI has been developed by the GDG.

CONCLUSION

We anticipate that these guidelines will promote the use of IONM to detect and manage ISCI, and promote the use of preoperative and intraoperative checklists by surgeons and other team members for high risk patients undergoing spine surgery. We welcome teams to implement and evaluate the care pathway created by our GDG.

Customized 3-dimensional-printed Vertebral Implants for Spinal Reconstruction After Tumor Resection: A Systematic Review

STUDY DESIGN

Systematic review.

OBJECTIVE

To examine the outcomes of customized 3-dimensional (3D) printed implants for spinal reconstruction after tumor resection.

SUMMARY OF BACKGROUND DATA

Various techniques exist for spinal reconstruction after tumor resection. Currently, there is no consensus regarding the utility of customized 3D-printed implants for spinal reconstruction after tumor resection.

MATERIALS AND METHODS

A systematic review was registered with PROSPERO and performed according to "Preferred Reporting Items for Systematic Reviews and Meta-analyses" guidelines. All level I-V evidence studies reporting the use of 3D-printed implants for spinal reconstruction after tumor resection were included.

RESULTS

Eleven studies (65 patients; mean age, 40.9 ± 18.1 y) were included. Eleven patients (16.9%) underwent intralesional resections with positive margins and 54 patients (83.1%) underwent en bloc spondylectomy with negative margins. All patients underwent vertebral reconstruction with 3D-printed titanium implants. Tumor involvement was in the cervical spine in 21 patients (32.3%), thoracic spine in 29 patients (44.6%), thoracolumbar junction in 2 patients (3.1%), and lumbar spine in 13 patients (20.0%). Ten studies with 62 patients reported perioperative outcomes radiologic/oncologic status at final follow-up. At the mean final follow-up of 18.5 ± 9.8 months, 47 patients (75.8%) had no evidence of disease, 9 patients (14.5%) were alive with recurrence, and 6 patients (9.7%) had died of disease. One patient who underwent C3-C5 en bloc spondylectomy had an asymptomatic subsidence of 2.7 mm at the final follow-up. Twenty patients that underwent thoracic and/or lumbar reconstruction had a mean subsidence of 3.8 ± 4.7 mm at the final follow-up; however, only 1 patient had a symptomatic subsidence that required revision surgery. Eleven patients (17.7%) had one or more major complications.

CONCLUSION

There is some evidence to suggest that using customized 3D-printed titanium or titanium alloy implants is an effective technique for spinal reconstruction after tumor resection. There is a high incidence of asymptomatic subsidence and major complications that are similar to other methods of reconstruction.

LEVEL OF EVIDENCE

Level V, systematic review of level I-V studies.

Vascular injury risk stratification for lateral lumbar interbody fusion (LLIF) at L4-L5: a morphometric study using magnetic resonance imaging

Background

Proper vascular injury risk stratification (VIRS) methods for L4-L5 lateral lumbar interbody fusion (LLIF) surgery have not been well-described. The objective of this study was to propose a novel VIRS method for L4-L5 LLIF surgery via the transpsoas approach.

Methods

Axial magnetic resonance imaging (MRI) of adult patients were obtained and analyzed. The VIRS scores were assessed using anterior disc line to posterior vessel wall distance, the disc vessel angle (DVA), and the disc edge to vessel distance at the level of L4-L5 disc space.

Results

Ninety-one consecutive adult patients were included in the study. The right common iliac vein (CIV) had a high risk of injury with both right- and left-sided approaches. The left CIV had a moderate risk with a left-sided approach when the iliocaval confluence was above the L4-L5 disc space but had a high risk when the confluence was at the L4-L5 disc space. The left CIV had a high risk with a right-sided approach when the confluence was above the L4-L5 disc space but had a moderate risk when the confluence was at the L4-L5 disc space. The inferior vena cava (IVC) had a high risk with both right- and left-sided approaches. The aorta had a moderate risk regardless of the right or left-sided approaches. The left common iliac artery (CIA) had a moderate risk with a right-sided approach and a low risk with a left-sided approach. The right CIA had a low risk with both right- and left-sided approaches.

Conclusions

There are significant vascular anatomic variations at the L4-L5 disc level and a proper VIRS can be performed utilizing a combination of anterior disc line to posterior vessel wall distance, DVA, and disc edge to vessel distance, on the axial MRI.

Anterior column realignment (ACR) for focal kyphotic spinal deformity using an anterior to psoas approach and anterior longitudinal ligament release

Background

The anterior-to-psoas (ATP) approach to the lumbar spine has been proposed as an alternative to the transpsoas approach for approaching the disc space without dissecting through the psoas muscle, thus decreasing the risk of injury to the lumbar plexus. There are no prior studies that evaluates the clinical application of anterior longitudinal ligament (ALL) release and anterior column realignment (ACR) using the ATP approach. The objective of this study was to describe and evaluate the safety of ACR using an ATP approach with release of both the ALL and bilateral annulus for correction of a focal kyphotic lumbar deformity.

Methods

A retrospective analysis of fourteen consecutive patients at a single institution between January 2017 and December 2019 of patients undergoing ACR using an ATP approach for lumbar flatback syndrome with focal kyphotic lumbar deformity by a single surgeon was performed. Primary outcome measures were pre- and postoperative radiographic parameters. Secondary outcome measures were perioperative adverse events (AEs), 30-day readmissions/reoperations, discharge disposition, post-operative length of stay (LOS), and radiographic complications.

Results

Fourteen consecutive patients (mean age 67.0±3.9 years, 8 males, 6 females) with 15 total ACR levels were included in the study. A grade 1 posterior column osteotomy (PCO) with posterior instrumentation was performed at all ACR levels. L2-L3 ACR was performed in nine patients, L3-L4 in four patients, and L4-L5 in two patients. Mean preoperative disk lordotic angle at the ACR level was 5.4°±5.9° of kyphosis. Mean increase in postoperative disk lordotic angle was 24.0°±8.5° at a mean follow-up of 34.0±23.4 months.

Conclusions

ACR can be performed with a complete ALL release under direct visualization using the ATP approach. This technique can be a safe and effective method for achieving substantial correction of a focal kyphotic deformity within the lumbar spine.

Characterizing neck injuries in the national football league: a descriptive epidemiology study

BACKGROUND

Neck injury is a common and often debilitating injury among athletes participating in American football. Limited data exists regarding neck injuries among elite athletes in the National Football League (NFL). To characterize the epidemiology of non-season ending, season-ending, and career-ending neck injuries in the NFL from 2016 through 2021.

METHODS

Athletes who sustained neck injuries were identified using the NFL's injured reserve (IR) list between the 2016 and 2021 seasons. Demographics and return to sport (RTS) data were collected. Available game footages were reviewed to identify the mechanism of injury (MOI). Injury incidence rates were calculated based on per team play basis.

RESULTS

During the 6-year study period, 464 players (mean age 26.8 ± 3.2 years) were placed on the injury reserve list due to neck injuries. There were 285 defensive players and 179 offensive players injured (61.4 vs 38.6%, respectively, p < 0.001). Defensive back was the most common position to sustain a neck injury (111 players, 23.9%). 407 players (87.7%) sustained non-season-ending injuries with a mean RTS at 9.2 ± 11.3 days. 36 players (7.8%) sustained season-ending injuries with a mean RTS at 378.6 ± 162.0 days. 21 players (4.5%) sustained career-ending injuries. The overall incidence of neck injuries was 23.5 per 10,000 team plays. The incidence of season-ending injuries and career-ending injuries were 1.82 and 1.06 per 10,000 team plays, respectively. There were 38 injuries with available footages for MOI assessment (23 non-season-ending, 9 season-ending, 6 career-ending). Head-to-head contact was seen in 15 injuries (39.5%), head-down tackling in 11 injuries (28.9%), direct extremity-to-head contact in 7 injuries (18.4%), and head-to-ground contact in 5 injuries (13.2%). There was no significant difference in age, position, or MOI among players sustaining non-season-ending, season-ending, and career-ending injuries.

CONCLUSION

There is a high incidence of neck injuries among NFL athletes with predictable MOIs including head-to-head contact, head-down tackling, direct extremity-to-head contact, and head-to-ground contact. Defensive players were more likely to sustain neck injuries compared to offensive players. Defensive back was the most common position to sustain a neck injury.

LEVEL OF EVIDENCE

III.

Postoperative Rehabilitation to Improve Outcomes After Cervical Spine Fusion for Degenerative Cervical Spondylosis: A Systematic Review

Postoperative rehabilitation has recently been identified as a high-priority research topic for improving surgical outcomes for degenerative cervical spondylosis (DCS). However, there remains no consensus on specific rehabilitation strategies. Thus, the objective of this study was to evaluate the effectiveness of postoperative rehabilitation strategies for short-term and long-term outcomes after cervical spine fusion for DCS. A systematic review was performed according to Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines using the PubMed, Scopus, and Ovid Medline databases. All level I-IV therapeutic studies in the English language investigating the outcomes of postoperative rehabilitation strategies after cervical spine fusion for DCS were included. Nine studies with 895 patients with DCS (747 anterior-only fusion, 55 patients with posterior-only fusion, 93 patients with physiotherapy alone) were included in this analysis, with 446 (49.8%) patients receiving physiotherapy alone or standard postoperative therapy and 449 (50.2%) patients receiving standard postoperative therapy with additional intervention or augmentation. These interventions included pulsed electromagnetic field (PEMF) stimulation, telephone-supported home exercise program (HEP), early cervical spine stabilizer training, structured postoperative therapy, and a postoperative cervical collar. One level II study demonstrated that PEMF led to increased fusion rates at six months postoperatively compared to standard therapy alone, one level II study demonstrated that postoperative cervical therapy in addition to standard therapy was better than standard therapy alone in the improvement of neck pain intensity, one level IV study demonstrated home exercise therapy led to an improvement in neck pain, arm pain, and disability, and six level II studies reported no difference in clinical outcome measures between augmented or targeted therapy and standard postoperative therapy for DCS. In conclusion, there is moderate evidence to suggest that there is no significant difference in clinical and surgical outcomes between standard postoperative therapy and augmented or targeted postoperative therapy for cervical fusion in the setting of cervical spondylosis. However, there is some evidence to support that certain therapeutic modalities, such as PEMF stimulation, may lead to improved fusion rates, clinical outcomes, and patient satisfaction when compared to standard postoperative therapy protocols. There is no evidence to support a difference in effectiveness with different types of postoperative rehabilitation strategies between anterior and posterior fusions for DCS.

Preoperative Serum Albumin Level Predicts Length of Stay and Perioperative Adverse Events Following Vertebral Corpectomy and Posterior Stabilization for Metastatic Spine Disease

STUDY DESIGN

Retrospective review of a prospectively collected national database.

OBJECTIVES

To determine the association between preoperative serum albumin levels and perioperative adverse events (AEs) following vertebral corpectomy and posterior stabilization for metastatic spine disease.

METHODS

The 2010 to 2019 American College of Surgeons' National Surgical Quality Improvement (ACS-NSQIP) database was used to identify all patients undergoing vertebral corpectomy and posterior stabilization for metastatic spine disease. Receiver operative characteristic (ROC) curve analysis was used to determine preoperative serum albumin cut-off values for predicting perioperative AEs. Low preoperative serum albumin was defined as serum albumin below this cut-off value.

RESULTS

A total of 301 patients were included in the study. ROC curve analysis demonstrated serum albumin < 3.25 g/dL as a cut-off value for predicting perioperative AEs. The low serum albumin group had a higher overall perioperative AEs (P = .041), longer post-operative LOS (P < .001), higher 30-day reoperation rate (P = .014), and a higher in-hospital mortality rate (P = .046). Multivariate analysis demonstrated that low preoperative serum albumin was associated with higher perioperative AEs.

CONCLUSIONS

Low serum albumin level is associated with higher perioperative AEs, longer postoperative LOS, and higher rates of 30-day reoperation and in-hospital mortality among patients undergoing vertebral corpectomy and posterior stabilization for metastatic spine disease. Strategies to improve preoperative nutritional status in patients undergoing this procedure may improve these perioperative outcome measures within this surgical population.

LEVEL OF EVIDENCE

III.

Obesity and perioperative adverse events in patients undergoing complex revision surgery for the thoracolumbar spine

Background

There are no previous studies that evaluate the effect of obesity on patients undergoing complex revision thoracolumbar spine surgery. The primary objective was to determine the relationship between obesity and perioperative adverse events (AEs) with patients undergoing complex revision thoracolumbar spine surgery while controlling for psoas muscle index (PMI) as a confounding variable. The secondary objective was to determine the relationship between obesity and 30-day readmission rates, 30-day re-operation rates, rate of discharge to a facility, and post-operative length of stay (LOS).

Methods

Between May 2016 and February 2020, a retrospective analysis of individuals undergoing complex revision surgery of the thoracolumbar spine was performed at a single institution. Obesity was defined as BMI ≥ 30.0 kg/m². PMI < 500 mm²/m² for males and < 412 mm²/m² for females were used to define low muscle mass. A Spine Surgical Invasiveness Index (SSII) > 10 was used to define complex revision surgery. A multivariable logistic regression model was used to ascertain the effects of low muscle mass, obesity, age, and gender on the likelihood of the occurrence of any AE.

Results

A total of 114 consecutive patients were included in the study. Fifty-four patients were in the obese cohort and 60 patients in the non-obese cohort. There was not a significant difference in perioperative outcomes of both the obese and non-obese patients. There were 22 obese patients (40.7%) and 33 non-obese patients (55.0%) that experienced any AE (p = 0.130).

Multivariable analysis demonstrated that individuals with low muscle mass had a significantly higher likelihood for an AE than individuals with normal or high muscle mass (OR: 7.53, 95% CI: 3.05-18.60). Obesity did not have a significant effect in predicting AEs.

Conclusions

Obesity is not associated with perioperative AEs, 30-day readmission rates, 30-day re-operation rates, rate of discharge to a facility, or post-operative length of stay (LOS) among patients undergoing complex revision thoracolumbar spine surgery.

Level of evidence

III

Determining C2 Pedicle Screw Placement Feasibility in the Pediatric Population: A Computed Tomographic Safe Zone Analysis

BACKGROUND

Due to high rates of anatomic variability of the C2 pedicle, thin-sliced pedicular-oriented computed tomography (CT) and 3-dimensional reconstructive CT technologies have been introduced to predict safe C2 pedicle screw placement. However, this technology may not be readily available in all centers. The purpose of this study was to perform a C2 pedicle safe zone analysis using standard sagittal CT scans to predict the feasibility of C2 pedicle screw placement in a pediatric population and to compare the results with our previously obtained safe zone analysis from the adult population.

METHODS

A retrospective analysis was performed at a single level I trauma center of pediatric patients who completed CT scans of the cervical spine. The feasibility of C2 pedicle screw placement was analyzed using our previously described C2 pedicle safe zone analysis technique. The risk profiles were compared with our previously obtained safe zone analysis from the adult population.

RESULTS

Thirty-nine consecutive patients with a mean age of 7.8±4.4 years and 78 total pedicles were included in the study. Fourteen pedicles (18%) were considered low risk, 37 (47%) were moderate risk, and 27 (35%) were high risk for vertebral artery injury. Individual patients were found to have a significant amount of side-to-side variability between pedicles with 21 patients (54%) having left and right pedicles with different risk profiles. Four patients (10%) demonstrated low risk profiles in bilateral pedicles. There was no significant difference between the risk profiles of pediatric and adult patients.

CONCLUSIONS

There is a considerable amount of anatomic variability within the pediatric C2 pedicles. Using this simple and accessible technique during the review of preoperative imaging, C2 pedicle screw placement may be considered in appropriately selected pediatric patients.

LEVEL OF EVIDENCE

Level III.

Sarcopenia predicts perioperative adverse events following complex revision surgery for the thoracolumbar spine

BACKGROUND CONTEXT

Sarcopenia measured by psoas muscle index (PMI) has been shown to predict perioperative mortality and adverse events (AEs) after various surgical procedures. However, this relationship has not been studied in complex revision thoracolumbar spine surgery.

PURPOSE

This study aimed to determine the relationship between sarcopenia and perioperative AEs among patients undergoing complex revision thoracolumbar spine surgery.

STUDY DESIGN

Retrospective cohort study PATIENT SAMPLE: A retrospective analysis was performed at a single institution between May 2016 and February 2020 of patients undergoing complex revision thoracolumbar spine surgery by three board certified fellowship-trained orthopaedic spine surgeons.

OUTCOME MEASURES

Perioperative adverse events including postoperative anemia requiring transfusion, cardiac complication, sepsis, wound complication, delirium, intra-operative dural tear, acute kidney injury, pneumonia, urinary tract infection, urinary retention, epidural hematoma, and deep vein thrombosis. Secondary outcome measures were 30-day readmission rates, 30-day re-operation rates, in-hospital mortality rates, discharge disposition, and postoperative length of stay (LOS).

METHODS

Sarcopenia was analyzed using PMI, calculated at the L3 vertebral body measured on preoperative magnetic resonance imaging (MRI) or computed tomography (CT) normalized to height² (mm²/m²). Receiver operating characteristic (ROC) curve analysis and Youden index were used to determine gender-specific PMI cut-off values for predicting perioperative AEs. Sarcopenia was defined as PMI below the cut-off values. Complex revision surgery was defined as Spine Surgical Invasiveness Index >10.

RESULTS

A total of 114 consecutive patients were included in the study. ROC curve analysis demonstrated PMI <500 mm²/m² for males and <412 mm²/m² for females as predictors for perioperative AEs. 49 patients were in the sarcopenia cohort and 65 patients in the nonsarcopenia cohort. The sarcopenia group had higher overall perioperative AEs (75.5% vs 27.7%, p<.001) and individual AEs including: postoperative anemia requiring transfusion, wound complication, delirium, acute kidney injury, pneumonia, urinary tract infection, and deep vein thrombosis. The sarcopenia group had higher 30-day reoperation rate (14.3% vs 3.1%, p=.037), 30-day readmission rate (16.3% vs 3.1%, p=.018), rate of discharge to a facility (83.7% vs 50.8%, p<.001), and longer length of stay (LOS) (7.3±4.2 days vs 5.6±3.5 days, p=.023).

CONCLUSIONS

Sarcopenia measured by PMI is associated with higher perioperative AEs, 30-day readmission rates, 30-day reoperation rates, rate of discharge to a facility, and longer LOS among patients undergoing complex revision thoracolumbar spine surgery.

At-Risk Tackling Techniques in American Football

Background

In American football, fewer fatalities and severe injuries have been seen annually since 1976, after data from 1971 through 1975 were retrospectively reviewed to better understand the mechanisms involved in catastrophic cervical spine injury and rules were enacted to prohibit certain types of aggressive tackling. The National Football Head and Neck Injury Registry was established in 1975.

Purpose

To assess (1) tackling techniques that coaches were teaching at 3 levels-youth level (YL; 4th to 5th grades), middle school (MS; 6th to 8th grades), and high school (HS; 9th to 12th grades); (2) tackling techniques used during games; and (3) the successful tackle rates of these techniques.

Study Design

Descriptive epidemiology study.

Methods

Surveys were distributed via email to 500 coaches of YL, MS, and HS football teams in Texas. Coaches provided video recordings of football games, and all tackle attempts were graded by a single reviewer who watched game videos; 1000 consecutive tackles were observed for each group. Survey data included how coaches instructed their players to tackle, the types of tackles, the number of tackles versus missed tackles, the head position, and the initial contact. Data were analyzed with the chi-square test. A subset of 100 consecutive tackles at each level of play was reviewed by 2 blinded reviewers to assess intra- and interrater reliabilities.

Results

In all groups, coaches responded that they preferred to teach the at-risk "head across the bow" tackling technique (83% YL, 81% MS, 75% HS). Coaches stated that they instructed players to "keep your head up," as currently recommended, 89% in YL, 100% in MS, and 81% in HS. During games, players used head-up, inside-shoulder tackles more successfully across all groups (97.5% YL, 99.5% MS, 98.8% HS). While intra- and interrater reliabilities were in the good range, these scores were lower in the youth group.

Conclusion

Our study supports the effectiveness of tackling with the head up and making the initial contact with the inside shoulder. Lower reliability ratings for the youth group were likely due to lower video quality and the lack of players' tackling experience.

Decreased radiation exposure using pulsed fluoroscopy and a detachable pedicle marker and probe to place pedicle screws: a comparison to current fluoroscopy techniques and CT navigation

STUDY DESIGN

Quality improvement evaluation with retrospective analysis.

OBJECTIVES

To compare a technique to place pedicle screws (PS) using a novel detachable pedicle marker and probe (DPMP) and pulsed fluoroscopy (PF) vs. conventional technique utilizing PF with standard instruments (SI) and O-arm. Spinal fusion with pedicle screw instrumentation (PSI) is the mainstay in treatment of spinal deformities. Reports suggest that CT navigated (O-arm) PS placement is more accurate than fluoroscopy. However, these studies have not considered the increased radiation exposure associated with CT.

METHODS

Thirty-six patients with spinal deformity had PSI using PF and DPMPs. Accuracy of PS placement and radiation data from 14 dosimeters placed on the patient and around the operating room was analyzed. Results were compared to published data.

RESULTS

Mean fluoroscopic time was 13.4 s (range 6.0-32.4), and the mean cumulative dose was 3.1 mGy (range 0.2-16.4). Median estimated effective dose to the patient was 0.22 mSv (range 0.0-0.7). The effective dose of radiation was reduced by 80% (0.22 mSv vs. 1.11 mSv) compared to low-dose O-arm. The surgical team did not receive any detectable radiation. The seconds of PF used to assist and confirm placement of PSs was reduced to 1.2 s/level compared to previous reports of 4.49 s/level using SIs. DPMPs reduced fluoroscopy to 0.84 s/PS compared to 7.36 s/PS using SIs to assist and confirm PS placement. PSs were accurately placed in 561 of 576 (97.4%), which is comparable to O-arm and fluoroscopy with SIs.

CONCLUSIONS

PS placement using PF and DPMPs to assist and confirm PS placement lowers radiation exposure to the patient and surgical team without compromising accuracy compared to O-arm and fluoroscopy with SIs.

LEVEL OF EVIDENCE

Therapeutic, Level IV (Retrospective case series, historical control).

Generation of patient-derived tumor xenografts from percutaneous tumor biopsies in children with bone sarcomas

One of the limitations of performing percutaneous biopsies in patients with bone sarcomas is the small amount of tumor that can be obtained for research purposes. Here, we describe our experience developing patient-derived tumor xenografts (PDXs) using percutaneous tumor biopsies in children with bone sarcomas. We generated 14 bone sarcoma PDXs from percutaneous tumor biopsies. We also developed eight bone sarcoma PDXs from surgical resection of primary bone tumors and pulmonary metastases. A multidisciplinary team approach was critical to establish an accurate diagnosis and to provide adequate tumor samples for PDX generation.

Radiologic Analysis of C2 to Predict Safe Placement of Pedicle Screws

Background

Preoperative assessment of C2 pedicle morphology is critical to safe pedicle screw placement. To avoid iatrogenic injury, complex digital templating software has been introduced; however, this technology may not be available in many centers. We report a technique for preoperative assessment of C2 pedicle screw placement safety based upon 2-dimensional sagittal computed tomography (CT) scan images and verify its utility in clinical practice.

Methods

A total of 46 consecutive patients underwent cervical spine CT scans between 2005 and 2011. The C2 pedicle morphology was assessed on sagittal CT imaging by 5 independent reviewers to determine the feasibility and risk associated with pedicle screw placement. Thirty consecutive patients underwent C2 pedicle screw placement and were followed clinically for a minimum of 2 years. The ability to place a screw was noted, and accuracy of screw placement was assessed postoperatively by CT scan.

Results

The CT scan analysis demonstrated that 11% (5/46) of patients had sufficient pedicle size bilaterally to allow safe placement of long pedicle screws with a low risk of vertebral artery injury, whereas 15% (7/46) were considered a high risk bilaterally. Screw placement was deemed low risk in 28%, moderate risk in 38%, and high risk in 34%. Excellent intraobserver reliability and good interobserver reliability was observed. Clinically, 18 of 20 (90%) low-risk and 21 of 24 (88%) moderate-risk pedicle screws were placed safely versus 5 of 16 (31%) high-risk pedicle screws (P < .001).

Conclusions

Using the described technique for evaluating the C2 pedicle via sagittal CT scan images allows for safe and reliable pedicle screw placement without relying upon complex digital templating software, which may have limited availability.

Level of Evidence

II.

Clinical Relevance

This study aids in the surgical decision-making behind the placement of C2 pedicle screws using CT scans without reliance upon complex digital templating software.

Modern Techniques for the Management of Metastatic Spine Disease

The management of metastatic spine disease has evolved substantially in the past 5 years. Early treatment approaches with more aggressive surgical indications were based on studies that misinterpreted or overemphasized the advantages of the surgical management of metastatic spine disease. However, substantial advantages in radiation therapy, chemotherapy, and biologic agents have led to considerable improvements in patient outcomes and have, in many patients, shifted the paradigm back to nonsurgical or less invasive treatment modalities. Surgeons should be aware of critiques of earlier treatment strategies and associated frameworks for the management of metastatic spine disease. The Medical, Oncologic, Stenosis, and Stability framework was developed to address some of the shortcomings of early metastatic spine disease treatment approaches.

A novel muscle-sparing high thoracotomy for upper thoracic spine resection and reconstruction

PURPOSE

High thoracotomy allows access to the anterior cervicothoracic and upper thoracic vertebrae; however, traditional techniques transect shoulder girdle muscles, leading to postoperative shoulder dysfunction. Muscle-sparing techniques diminish this concern, but often sacrifice the quality of exposure. We describe a novel muscle-sparing, high thoracotomy approach for the treatment of ventral cervicothoracic and upper thoracic spine lesions.

METHODS

A novel muscle-sparing, high thoracotomy approach is described, utilizing a midline posterior incision with lateral extension from the lateral decubitus position. Five patients are presented to illustrate the application of this technique in thoracic tumors with intimate spinal involvement.

RESULTS

The muscle-sparing, high thoracotomy approach afforded gross total resection and spinal reconstruction in five consecutive patients, including stage IV lung carcinoma with invasion of the T5 and T6 vertebral bodies, two malignant fibrous histiocytomas causing thoracic cord compression, a metastatic T6 lesion of unknown primary with associated cord compression; and a Pancoast tumor. All patients seen at 6 months had full symmetric shoulder range of motion postoperatively.

CONCLUSIONS

The described muscle-sparing, high thoracotomy approach provides excellent exposure of the ventral cervicothoracic and upper thoracic spine without the morbidity associated with the transection of shoulder girdle muscle bellies. This technique is particularly useful in patients with primary malignant bone tumors requiring en bloc excision and metastatic tumors with large soft tissue components.

Case Report: Angiosarcoma in the Upper Extremity Related to a Nonfunctioning Arteriovenous Fistula

BACKGROUND

Angiosarcoma is a rare but aggressive malignancy with a high predilection for the head and neck. There have been few case reports of the development of angiosarcoma in a nonfunctional arteriovenous fistula in a hemodialysis patient.

METHODS

After institutional review board approval, a retrospective chart analysis is conducted to present the case of a patient who received plastic surgical treatment at our hospital.

RESULTS

We present the case of a 44-year-old male who presented with ischemic changes and paresthesias of the upper extremity associated with the development of angiosarcoma in an arteriovenous fistula.

CONCLUSIONS

Angiosarcoma remains a rare but important diagnosis to include in the differential diagnosis for upper extremity pain and paresthesias in chronic renal failure and nonfunctioning arteriovenous fistula.

Thoracolumbar burst fractures treated with posterior decompression and pedicle screw instrumentation supplemented with balloon-assisted vertebroplasty and calcium phosphate reconstruction. Surgical technique

BACKGROUND

The treatment of unstable thoracolumbar burst fractures with short-segment posterior spinal instrumentation without anterior column reconstruction is associated with a high rate of screw breakage and progressive loss of reduction. The purpose of the present study was to evaluate the functional, neurologic, and radiographic results following transpedicular, balloon-assisted fracture reduction with anterior column reconstruction with use of calcium phosphate bone cement combined with short-segment posterior instrumentation and a laminectomy.

METHODS

A consecutive series of thirty-eight patients with an unstable thoracolumbar burst fracture with or without neurologic deficit were managed with transpedicular, balloon-assisted fracture reduction, calcium phosphate bone cement reconstruction, and short-segment spinal instrumentation from 2002 to 2005. Twenty-eight of the thirty-eight patients were followed for a minimum of two years. Demographic data, neurologic function, segmental kyphosis, the fracture severity score, canal compromise, the Short Form-36 score, the Oswestry Disability Index score, and treatment-related complications were evaluated prospectively.

RESULTS

All thirteen patients with incomplete neurologic deficits had improvement by at least one Frankel grade. The mean kyphotic angulation improved from 17 degrees preoperatively to 7 degrees at the time of the latest follow-up, and the loss of vertebral body height improved from a mean of 42% preoperatively to 14% at the time of the latest follow-up. Screw breakage occurred in two patients, and pseudarthrosis occurred in one patient.

CONCLUSIONS

The present study demonstrates that excellent reduction of unstable thoracolumbar burst fractures with and without associated neurologic deficits can be maintained with use of short-segment instrumentation and a transpedicular balloon-assisted reduction combined with anterior column reconstruction with calcium phosphate bone cement performed through a single posterior incision. The resultant circumferential stabilization combined with a decompressive laminectomy led to maintained or improved neurologic function in all patients with neurologic deficits, with a low rate of instrumentation failure and loss of correction.

Thoracolumbar burst fractures treated with posterior decompression and pedicle screw instrumentation supplemented with balloon-assisted vertebroplasty and calcium phosphate reconstruction

BACKGROUND

The treatment of unstable thoracolumbar burst fractures with short-segment posterior spinal instrumentation without anterior column reconstruction is associated with a high rate of screw breakage and progressive loss of reduction. The purpose of the present study was to evaluate the functional, neurologic, and radiographic results following transpedicular, balloon-assisted fracture reduction with anterior column reconstruction with use of calcium phosphate bone cement combined with short-segment posterior instrumentation and a laminectomy.

METHODS

A consecutive series of thirty-eight patients with an unstable thoracolumbar burst fracture with or without neurologic deficit were managed with transpedicular, balloon-assisted fracture reduction, calcium phosphate bone cement reconstruction, and short-segment spinal instrumentation from 2002 to 2005. Twenty-eight of the thirty-eight patients were followed for a minimum of two years. Demographic data, neurologic function, segmental kyphosis, the fracture severity score, canal compromise, the Short Form-36 score, the Oswestry Disability Index score, and treatment-related complications were evaluated prospectively.

RESULTS

All thirteen patients with incomplete neurologic deficits had improvement by at least one Frankel grade. The mean kyphotic angulation improved from 17 degrees preoperatively to 7 degrees at the time of the latest follow-up, and the loss of vertebral body height improved from a mean of 42% preoperatively to 14% at the time of the latest follow-up. Screw breakage occurred in two patients, and pseudarthrosis occurred in one patient.

CONCLUSIONS

The present study demonstrates that excellent reduction of unstable thoracolumbar burst fractures with and without associated neurologic deficits can be maintained with use of short-segment instrumentation and a transpedicular balloon-assisted reduction combined with anterior column reconstruction with calcium phosphate bone cement performed through a single posterior incision. The resultant circumferential stabilization combined with a decompressive laminectomy led to maintained or improved neurologic function in all patients with neurologic deficits, with a low rate of instrumentation failure and loss of correction.

Characterization of graft subsidence in anterior cervical discectomy and fusion with rigid anterior plate fixation

This study addressed radiographically the evaluation, presence, location, and degree of subsidence with secondary focus on the various clinical parameters and outcomes in 32 patients who underwent anterior cervical discectomy and fusion (ACDF) with tricortical iliac crest bone grafts and rigid anterior plate fixation. Postoperative follow-up plain radiographs were evaluated to determine subsidence on lateral neutral images by measuring the change in height of interscrew distance (ISD) and anterior (AVD), mid (MVD), and posterior (PVD) vertebral endplate-to-endplate vertical distances. Clinical functional outcome and various risk factors were also addressed. A 100% fusion rate was achieved, no instrumentation-related complications were noted, and mild graft subsidence occurred in each patient after the initial 2 months of surgery. Mean AVD, MVD, and PVD were 1.2 mm, 0.4 mm and 0.6 mm, respectively. Mean ISD was 0.6 mm. Percent change for AVD, MVD, PVD, and ISD was 2.3%, 0.8%, 1.2%, and 1.2%, respectively. Subsidence was more pronounced at the anterior vertebral graft-endplate interface (P < .05). Satisfactory clinical results were reported in 90.9% of the patients. With such a sample size, age, sex, smoking status, plate design, graft type, and operative or number of fused levels did not demonstrate statistically significant differences to the degree of subsidence. This paper has shown that ACDF with tricortical bone grafts and rigid plating is associated with slight subsidence, graft load-sharing, high fusion rate, and excellent clinical outcome.

Osteochondroma of the sacrum: a case report and review of the literature

STUDY DESIGN

A case report and review of the literature.

OBJECTIVES

To describe the en bloc excision and postoperative outcome of an osteochondroma of the sacrum compressing the neural elements, as well as review the literature on solitary osteochondroma involving the sacrum.

SUMMARY OF BACKGROUND DATA

Osteochondroma is the most common primary benign bone tumor. However, this tumor rarely involves the spine and even more rarely involves the sacrum. To the best of our knowledge, en bloc excision of a solitary osteochondroma of the sacrum has not been previously reported.

METHODS

An 11-year-old male presented with disabling radicular pain in the right lower extremity. Radiologic studies showed a lesion occurring from the sacral lamina that was compressing the S2 nerve root. The tumor was excised en bloc through a posterior approach. The cavitary defect within the sacrum was reconstructed with crushed cancellous allograft and demineralized bone matrix putty. A literature review of solitary sacral osteochondroma was conducted of the English-based medical literature.

RESULTS

Histologic studies showed the tumor to be an osteochondroma. After surgery, pain was completely relieved, and neurologic function was normal. At the last follow-up, the sacroiliac joint remained intact, and there was no evidence of local recurrence. A literature review revealed 4 previous cases addressing osteochondroma of the sacrum.

CONCLUSIONS

Osteochondroma is a rare primary benign bone tumor that can occur in the sacrum. Local contamination and, therefore, the likelihood of local recurrence, are decreased when an en bloc, as opposed to an intralesional, excision is performed.

Multilevel en bloc spondylectomy and chest wall excision via a simultaneous anterior and posterior approach for Ewing sarcoma

STUDY DESIGN

A case study of a patient with Ewing sarcoma of T8 and T9 with paravertebral and chest wall involvement, who underwent neoadjuvant chemotherapy and subsequent multilevel en bloc spondylectomy and chest wall excision using a simultaneous anterior and posterior approach.

OBJECTIVE

To show the feasibility of treating Ewing sarcoma of the thoracic spine with paravertebral and chest wall extension by multiagent chemotherapy followed by a multilevel en bloc spondylectomy and chest wall excision using a simultaneous anterior and posterior approach.

SUMMARY OF BACKGROUND DATA

Ewing sarcoma is a primary malignant bone tumor that occasionally involves the spinal column. Most patients with Ewing sarcoma of the spine are treated with systemic chemotherapy followed by definitive local control. Radiation therapy is the usual mode of local control in these patients because the spinal column has historically been considered a surgically inaccessible site where wide surgical margins are difficult to obtain. However, en bloc spondylectomy techniques have been described that can probably further decrease the risk of local recurrence, thereby minimizing or even eliminating the need for radiation therapy. To our knowledge, a combined en bloc spondylectomy and chest wall excision in a patient with Ewing sarcoma in the spine has not been previously reported.

METHODS

Neoadjuvant chemotherapy consisting of vincristine, doxorubicin, and cyclophosphamide was administered. After completion of the chemotherapy, an en bloc spondylectomy of T8 and T9 with removal of the chest wall was achieved using a simultaneous anterior and posterior approach to the spine. A stackable carbon fiber cage filled with autograft and allograft bone was inserted between T7 and T10. The spine was stabilized with anterior and posterior instrumentation. The chest wall was reconstructed with contoured polymethylmethacrylate and polypropylene (Marlex, Textile Development Associates, Inc., Franklin Square, NY) mesh.

RESULTS

The patient maintained normal neurologic function, and pain was lessened. The margins were free of tumor, and tumor necrosis was 100%. After surgery, radiotherapy was not administered. No local tumor recurrence or distant metastases were evident at the last follow-up. Balance in the coronal and sagittal planes was maintained. The patient has returned to work and resumed normal activities of daily living.

CONCLUSIONS

Multilevel en bloc spondylectomy and chest wall excision performed using a simultaneous anterior and posterior approach is a safe and effective technique that may be used to achieve adequate margins in select patients with malignant tumors involving the thoracic spine and chest wall. This technique can eliminate the need for radiation therapy in patients with Ewing sarcoma and probably decreases the risk of local recurrence compared with radiation therapy alone.

Ewing's sarcoma of the mobile spine

STUDY DESIGN

A retrospective analysis was performed.

OBJECTIVES

To determine the oncological outcome of patients with nonmetastatic Ewing's sarcoma of the mobile spine treated with systemic multiagent chemotherapy combined with radiation therapy for definitive local control.

SUMMARY OF BACKGROUND DATA

To our knowledge, there are no studies that evaluate the oncological outcome of patients with nonmetastatic Ewing's sarcoma of the mobile spine treated with systemic chemotherapy and radiation therapy for definitive local control.

METHODS

Thirteen patients with nonmetastatic Ewing's sarcoma of the mobile spine were treated with high-dose multiagent chemotherapy combined with radiation therapy for definitive local control from 1971 to 2000 at a single institution. Patients were observed for a minimum of 2 years or until death. Neurological function, local recurrence, distant relapse, and treatment-related complications were evaluated.

RESULTS

There were 8 females and 5 males with a mean age of 19 years (ranging from 7-26 years). The mean follow-up time was 65 months (median 28 months; ranging from 2 to 218 months). All patients presented with pain. Motor deficits were present in 6 patients. Ten patients had a decompressive laminectomy. Improved pain control, as determined by narcotic use, was noted in 12 (92%) patients. Ten patients maintained or improved motor function by at least 1 Frankel grade, while 3 had deterioration of motor function. The disease-free survival rate was 49% and 36% at 5 and 10 years. Five (38%) patients were free of disease at last follow-up. Seven patients developed metastatic disease. Three (23%) patients developed a local recurrence. One of these patients had paraplegia associated with the local recurrence. Five patients developed 8 treatment-related complications. Four of the 10 (40%) patients that had a laminectomy developed progressive kyphosis. Two of these patients also developed late-onset cauda equina syndrome along with the deformity. One of these patients also developed cardiomyopathy associated with adriamycin cardiotoxicity. One patient developed a nonhealing pressure ulcerover a prominent spinous process.

CONCLUSIONS

The current study provides historical data on a relatively homogeneous group of patients withEwing's sarcoma of the mobile spine treated with multiagent chemotherapy combined with radiation therapy for definitive local control. Systemic chemotherapy combined with current spinal resection and reconstruction techniques may lead to improved oncological and clinical outcomes.

Alpha 4 integrin increases anoikis of human osteosarcoma cells

Cell motility, growth, and proliferation are regulated by adhesion to the extracellular matrix. Detachment of adherent cells from extracellular matrix results in induction of apoptosis ("anoikis"). Transformed cells often show an anchorage-independent growth that enables them to acquire a motile, invasive phenotype. This phenotype has been associated with the altered expression and function of the integrin family of transmembrane proteins that mediate cell adhesion to the extracellular matrix. Although alpha4 integrin is normally expressed on leukocyte subpopulations, a number of metastatic melanomas and sarcomas express it as well. In this study, we demonstrated the expression of alpha4 integrins on the human osteosarcoma cell line SAOS and on metastatic osteosarcoma lesions from the lung and pericardium. We further demonstrated that alpha4 integrin is coupled to the beta1 subunit by biochemical analysis and by using a mAb directed against a combinatorial epitope unique to the alpha4beta1 molecule. SAOS cells undergo anoikis when adherence is denied. Anoikis involved the activation of caspase 3 and the release of cytochrome c from mitochondria. Treatment of non-adherent SAOS with an anti-alpha4 mAb increased anoikis while anti-beta1 integrin mAbs did not alter anoikis, thus indicating a novel function for the alpha4 subunit in the control of cell death. Since integrins can control cell migration, proliferation, and apoptosis these results demonstrate a potential role for alpha4 integrin during multiple aspects of osteosarcoma metastasis.