Radiotherapy for Brain Metastases from Thyroid Cancer: An Institutional and National Retrospective Cohort Study.

Background: Stereotactic radiosurgery (SRS) is the standard of care for patients with a limited number of brain metastases. Despite the fact that the seminal studies regarding SRS for brain metastases were largely tissue agnostic, several current national guidelines do not uniformly recommend SRS in thyroid cancer. We therefore investigated oncological outcomes in a cohort of patients with brain metastases from thyroid cancer who received radiotherapy (RT) at our institution as well as those in a nationally representative cancer cohort, the National Cancer Database (NCDB). Materials and Methods: We identified patients with thyroid cancer and brain metastases treated with RT at our institution from 2002 through 2020. For the NCDB cohort, the national database of patients with thyroid cancer was screened on the basis of brain-directed RT or brain metastases. For the institutional cohort, the cumulative risk of local failure (LF), distant intracranial failure, and radiation necrosis were calculated, adjusted for the competing risk of death. Overall survival (OS) in both cohorts was analyzed using the Kaplan-Meier method. Univariate analysis was accomplished via clustered competing risks regression. Results: For the institutional cohort, we identified 33 patients with 212 treated brain metastases. OS was 6.6 months. The 1-year cumulative incidences of LF and distant intracranial failures were 7.0% and 38%, respectively. The 1-year risk of radiation necrosis was 3.3%. In the NCDB cohort, there were 289 patients, and the median survival was 10.2 months. NCDB national practice patterns analysis showed an increasing use of SRS over time in both the entire cohort and the subset of anaplastic patients. Univariate analysis was performed for OS, risk of LF, risk of regional intracranial failure, and risk of radiation necrosis. Conclusions: SRS is a safe, effective, and increasingly utilized treatment for thyroid cancer brain metastases of any histology and should be the standard of care treatment.

Spontaneous intracranial hypotension secondary to anterior thoracic osteophyte: Resolution after primary dural repair via posterior approach.

INTRODUCTION: Spontaneous intracranial hypotension (SIH) is an uncommon syndrome widely attributed to CSF hypovolemia, typically secondary to spontaneous CSF leak. Although commonly associated with postural headache and variable neurological symptoms, one of the most severe consequences of SIH is bilateral subdural hematomas with resultant neurological deterioration. PRESENTATION OF CASE: We present the case of a patient diagnosed with SIH secondary to an anteriorly positioned thoracic osteophyte with resultant dural disruption, who after multiple attempts at nonsurgical management developed bilateral subdural hematomas necessitating emergent surgical intervention. The patient underwent a unilateral posterior repair of his osteophyte with successful anterior decompression. At 36months follow up, the patient reported completely resolved headaches with no focal neurological deficits. DISCUSSION: We outline our posterior approach to repair of the dural defect and review the management algorithm for the treatment of patients with SIH. We also examine the current hypotheses as to the origin, pathophysiology, diagnosis and treatment of this syndrome. CONCLUSION: A posterior approach was utilized to repair the dural defect caused by an anterior thoracic osteophyte in a patient with severe SIH complicated by bilateral subdural hematomas. This approach minimizes morbidity compared to an anterior approach and allowed for removal of the osteophyte and repair of the dural defect.

National trends in spinal fusion for cervical spondylotic myelopathy.

BACKGROUND: The objective of this study is to provide a retrospective analysis using an NIS database to examine national trends in outcomes for CSM from 1993 to 2002. METHODS: Data for CSM admissions (n = 138792) were extracted from the 1993 to 2002 NIS database to determine overall outcomes, as well as for those patients with CSM who underwent spinal fusion. Data from 1993 to 1997 (period 1) were compared with data from 1998 to 2002 (period 2). RESULTS: The number of patients admitted with CSM increased 2-fold from 3.73 to 7.88 per 100000 US population. Approximately 10% of patients were admitted from the ED and 42% underwent spinal fusion. The number of patients with CSM that underwent spinal fusion increased 7-fold from 0.6 to 4.1 per 100000 people over the period from 1993 to 2002. Most spinal fusions were performed in the 45- to 64-year age group. The number of patients with 2 or more comorbidities increased from 20% to 37%; however, the mortality and adverse outcome rates remained stable, and there was a slight decrease in LOS. CONCLUSIONS: Cervical spondylotic myelopathy is one of the most common disorders treated by spine surgeons. There was a nearly 7-fold increase in the number of spinal fusions for CSM from 1993 to 2002. Despite continued increases in patient medical comorbidities, overall complication rates have remained stable at approximately 10.3% and mortality rates constant at 0.6%.

Automated intraoperative EMG testing during percutaneous pedicle screw placement.

BACKGROUND: EMG screw testing has been shown to be sensitive and reliable in open spinal instrumentation cases. However, there is little evidence to show its applicability to percutaneous screw placement. PURPOSE: To demonstrate the utility of EMG testing in percutaneous techniques, where lack of direct visualization poses an added risk to nerve injury. STUDY DESIGN: Summary of intraoperative EMG results during percutaneous pedicle screw placement. METHODS: Percutaneous pedicle screws were placed in twenty patients (22 levels, 88 pedicles). The initial fluoroscopically-guided k-wires and the subsequent taps were insulated and stimulated via an automated EMG system. Low threshold values prompted repositioning of the pedicle trajectory. RESULTS: Four (5%) k-wires induced EMG thresholds less than 10mA, prompting repositioning. One was repositioned without improvement, but with improvement upon tapping. One k-wire with very low threshold (3mA) was repositioned with an improved result (13mA). In 78 pedicles (89%) the tap threshold was greater than the k-wire. CONCLUSIONS: EMG testing helps to identify suboptimal screw trajectories, allowing for early adjustment and confirmation of improved placement. Tapping often improved thresholds, perhaps by compressing the bone and creating a denser, more insulative pedicle wall. EMG testing may improve the safety of percutaneous screw techniques, where the pedicle cannot be visually inspected.

The effect of anterior cervical fusion on neck motion.

STUDY DESIGN: Prospective cohort study. OBJECTIVE: To precisely measure the effect of anterior cervical fusion on neck motion. SUMMARY OF BACKGROUND DATA: Anterior cervical decompression and stabilization procedures are successful in treating recalcitrant cervical radiculopathy and cervical myelopathy. Most assume that these "fusion" procedures result in a loss of neck motion, although changes in overall motion following anterior cervical fusion have never been precisely quantified. METHODS: Twenty-five consecutive patients undergoing anterior cervical fusion of one to four levels underwent cervical range of motion testing in three planes using an unconstrained instrumented linkage before surgery and more than 3 months after surgery. These data were compared with that of 10 volunteers with no prior history of neck complaints. Motion data were compared between patients and volunteers, and between the patients before surgery and at last follow-up, using RMANOVA and Fisher's PLSD post hoc test. RESULTS: Before surgery, the patients had significantly less motion than the volunteers in all directions. Following surgical fusion, patients gained a statistically significant amount of motion in all planes, although they did not achieve the motion seen among the volunteers. Gains in motion were seen among all patients, including those undergoing four-level fusions, and there was no correlation between postoperative motion and the number of levels fused. CONCLUSIONS: Patients undergoing anterior cervical fusion have diminished neck motion compared with normal volunteers. Following surgery, they may be expected to gain motion, even when undergoing multilevel fusions. However, these patients are unlikely to regain the neck motion seen among normal individuals without neck complaints.

Conjoined lumbar nerve roots: a frequently underappreciated congenital abnormality.

Nerve root anomalies are frequently underrecognized on advanced imaging studies and may account for some percentage of failed spinal surgical procedures. The conjoined nerve root represents the most common nerve root anomaly. It is a well-known cause of false-positive readings for bulging and herniated disks in patients with purely axial neuroimaging studies. A retrospective evaluation of consecutive microsurgical lumbar diskectomies in 80 patients during a 5-year period was undertaken. A total of four patients (5%) were found intraoperatively to have evidence of a conjoined nerve root by the classification of Neidre. None was diagnosed preoperatively. Coronal magnetic resonance imaging offers the best means of visualizing a conjoined nerve root. The chance for a successful operation can be significantly enhanced if the surgeon is prepared to encounter this pathology.

Radiographic analysis of transforaminal lumbar interbody fusion for the treatment of adult isthmic spondylolisthesis.

The radiographs of 35 consecutive adult patients with isthmic spondylolisthesis who underwent a transforaminal lumbar interbody fusion (TLIF) with one or two Brantigan carbon fiber cages and pedicle screw instrumentation were evaluated. Anterolisthesis, disk space height, and slip angle were measured in preoperative and postoperative standing neutral radiographs. Anterolisthesis was reduced and disk space height was increased with the TLIF procedure. Average slip angle, however, was not significantly altered. The restoration of lordosis across the listhetic disk space correlated with a more anterior placement of the interbody cage within the disk space. The TLIF technique, performed with the Brantigan cage and pedicle screw instrumentation, appears to be able to restore disk height and reduce forward translation in patients with isthmic spondylolisthesis, but improvement in sagittal alignment is dependent upon anterior placement of the interbody device.

Acute sports-related spinal cord injury: contemporary management principles.

Improvements in helmet and equipment design have led to significant decreases in overall injury incidence, but no available helmet can prevent catastrophic injury to the neck and cervical spine. The most effective strategy for preventing this type of injury appears to be careful instruction, training, and regulations designed to eliminate head-first contact. The incidence of football-related quadriplegia has decreased from a peak of 13 cases per one million players between 1976 and 1980 to 3 per million from 1991 to 1993, mostly as a result of systematic research and an organized effort to eliminate high-risk behavior. An episode of transient quadriparesis does not appear to be a risk factor for catastrophic spinal cord injury. Torg reported that 0 of 117 quadriplegics in the National Football Head and Neck Injuries Registry recalled a prior episode of transient quadriparesis, and 0 of the 45 patients originally studied in his transient quadriparesis cohort have subsequently suffered quadriplegia. The significance of developmental spinal stenosis is unclear. Plain radiographic identification of a narrow spinal canal in a player sustaining cervical cord neurapraxia warrants further evaluation by MRI to rule out functional stenosis. The presence of actual cord deformation or compression on MRI should preclude participation in high-risk contact or collision sports.

Physical and monetary costs associated with autogenous bone graft harvesting.

Although autogenous iliac bone is frequently used for bone graft, many well-documented complications are associated with this procedure-including chronic pain; nerve, arterial, and ureteral injury; herniation of abdominal contents; sacroiliac joint instability; pelvic fractures; hematoma; and infection. An understanding of the morbidities associated with bone graft harvesting and of the strategies for avoiding them is imperative for surgeons using this grafting source. In addition, although synthetic grafting materials are considered relatively expensive compared with autogenous sources, the majority of physicians are unaware of the actual direct and indirect costs associated with autogenous bone graft harvesting. Contemporary allograft and synthetic grafting composites are being developed to optimize and surpass the native qualities of autogenous sources (ie, osteogenesis, osteoinductivity, osteoconductivity). Careful comparison of the cost of these alternative sources with the physical and monetary costs of autogenous bone graft will undoubtedly make allograft, recombinant, synthetic graft composites the logical choice in the very near future.

Bone grafting alternatives in spinal surgery.

BACKGROUND CONTEXT: Bone grafting is used to augment bone healing and provide stability after spinal surgery. Autologous bone graft is limited in quantity and unfortunately associated with increased surgical time and donor-site morbidity. Alternatives to bone grafting in spinal surgery include the use of allografts, osteoinductive growth factors such as bone morphogenetic proteins and various synthetic osteoconductive carriers. PURPOSE: Recent research has provided insight into methods that may modulate the bone healing process at the cellular level in addition to reversing the effects of symptomatic disc degeneration, which is a potentially disabling condition, managed frequently with various fusion procedures. With many adjuncts and alternatives available for use in spinal surgery, a concise review of the current bone grafting alternatives in spinal surgery is necessary. STUDY DESIGN/SETTING: A systematic review of the contemporary English literature on bone grafting in spinal surgery, including abstract information presented at national meetings. METHODS: Bone grafting alternatives were reviewed as to their efficacy in extending or replacing autologous bone graft sources in spinal applications. RESULTS: Alternatives to autologous bone graft include allograft bone, demineralized bone matrix, recombinant growth factors and synthetic implants. Each of these alternatives could possibly be combined with autologous bone marrow or various growth factors. Although none of the presently available substitutes provides all three of the fundamental properties of autograft bone (osteogenicity, osteoconductivity and osteoinductivity), there are a number of situations in which they have proven clinically useful. CONCLUSIONS: Alternatives to autogenous bone grafting find their greatest appeal when autograft bone is limited in supply or when acceptable rates of fusion may be achieved with these substitutes (or extenders) despite the absence of one or more of the properties of autologous bone graft. In these clinical situations, the morbidity of autograft harvest is reasonably avoided. Future research may discover that combinations of materials may cumulatively result in the expression of osteogenesis, osteoinductivity and osteoconductivity found in autogenous sources.