Does levelling of T1 tilt intra-operatively affect post-operative shoulder balance in adolescent idiopathic scoliosis patients?

INTRODUCTION: Previous studies have shown that T1 tilt is positively correlated with post-operative shoulder balance (SB). The aim of this study was to explore the role of intra-operative T1 tilt, among other shoulder parameters as a potential parameter to predict post-operative SB in adolescent idiopathic scoliosis (AIS) patients. METHODS: A retrospective review of AIS patients with structural thoracic curves with minimum 2 year follow up was conducted from a single tertiary center. Standing pre-operative, 1st erect, 1 year and 2-year follow-up; and intra-operative final prone radiographs were reviewed along with clinical data. Patients were stratified into 2 cohorts: Group A-Final intra-operative T1 tilt ≤5° and Group B-Final intra-operative T1 tilt >5°. These groups were compared for post-operative SB as a whole and separately for patients with baseline right or left shoulder high and if UIV was T2 or T3/T4. Patients with optimal SB (Radiographic shoulder height (RSH) <2 cm) at 2 years were compared to sub-optimal SB (RSH ≥ 2 cm) with respect to multiple SB variables. RESULTS: 55 patients (mean age 15.1 years-old, 43 F, mean BMI 22, mean thoracic Cobb-49.8°) were included. Based on Lenke curve types, there were 13 patients with type 1A, 10 patients with 1B, 12 patients with 1C, 7 patients with 2A, 4 patients with 2B and 9 patients with type 3C. T1 tilt was significantly correlated with RSH, Clavicle angle difference (CAD), First Rib Angle (FRA), and UIV tilt at first erect, 1-year, and 2-year post-op radiographs (p < 0.05 for all). When comparing groups, A and B, Group A patients showed significantly better restoration of their 2-year SB parameters; RSH (6.8 vs 11.8 mm, p = 0.01), CAD (3.9 vs 9.1 p < 0.001) and T1 tilt (4.7 vs 7.8° p = 0.01). Similar results were found for patients with baseline right shoulder high; RSH (p = 0.04), CAD (p < 0.001) and T1 tilt (p < 0.001) and whether UIV was T2 or T3/T4. Eight patients with sub-optimal SB had worse intra-operative T1 tilt (p = 0.03) compared to 47 patients with optimal SB despite no difference in MT Cobb correction (83.1 vs 79.8%, p = 0.57). CONCLUSION: Post-operative T1 tilt correlates with lateral shoulder parameters at first erect, 1 year, and 2-year radiographs. Therefore, T1 tilt can potentially be used as a surrogate to predict post-operative SB. Leveling intra-operative T1 tilt ≤5° is associated with better 2-year post-operative shoulder balance parameters irrespective of whether the UIV was T2 or T3/T4. Patients with sub-optimal SB at 2 years had worse final intra-operative T1 tilt despite similar percent correction of main thoracic curve for all patients.

Use of navigation for anterior and posterior instrumentation in the surgical management of pediatric pathologic lumbosacral deformity.

We report the use of computerized tomography (CT)-guided navigation for complex spinal deformity correction (anterior and posterior) in an 8-year-old patient with neurofibromatosis complicated by dystrophic pedicles, dural ectasia, and extensive vertebral scalloping. A retrospective review was conducted of the patient's medical records for the past 3 years, including the patient's office visit notes, operative reports, pre- and 2-year postoperative imaging studies. The patient successfully underwent anterior lumbar interbody fusion from L3-S1 using CT-guided navigation to negotiate the challenges posed by dural ectasia and vertebral body scalloping. One week after the anterior procedure, she underwent navigation-guided T10-to-pelvis posterior instrumented fusion. There were no perioperative or postoperative complications at 2 years. In patients with complex deformities of the spine, including dural ectasia, scalloped vertebral bodies, and decreased pedicle integrity, the use of intraoperative CT-guided navigation can benefit surgeons by facilitating the safe placement of interbody spacers and pedicle screws.

Role of Topical Tranexamic Acid on Blood Loss and Transfusion Requirements in Spinal Fusion for Neuromuscular and Syndromic Scoliosis.

STUDY DESIGN: Retrospective case control study. OBJECTIVES: To determine the role of TXA when used as topical soaked sponges (tTXA) on peri-operative blood loss and changes in hemoglobin following posterior spinal fusion (PSF) for neuromuscular and syndromic scoliosis (NMS). METHODS: A single center review of NMS patients who underwent PSF was conducted. The initial set of patients where no tTXA (control) was used were compared to consecutive NMS patients in whom tTXA was used. In the tTXA group, sponges soaked in 1g TXA in 500 mL normal saline were packed in the wound instead of dry sponges. Estimated blood loss (EBL) was calculated intraoperatively using a standard way. Pre-operative, intra-operative and immediate post-operative variables were collected and compared between the 2 groups. RESULTS: 33 patients were included (mean age- 13.5 yrs., BMI- 21, 17 patients in tTXA and 16 patients in control group). Pre-op demographic and radiographic variables were similar between the 2 groups. EBL, EBL per level, EBVL, operative time and number of levels fused were similar in both groups. tTXA group received less intra-operative pRBC transfusion as compared to the control group (150 ± 214 vs 363 ± 186 cc, P = .004). No difference was noted in post-op blood transfusion and drain output for 3 days in both the groups. tTXA group had lesser hospital (5.1 vs 8.9 days) and ICU length of stay (2 vs 4.2 days) and fewer immediate post-operative complications (23.5 vs 52.9%) compared to the control group but not statistically significant (P > .05). CONCLUSION: Administration of tTXA-soaked sponges is an effective and safe method to reduce intraoperative blood transfusion requirements in the correction of spinal deformity in patients with NMS.

L5 spondylolysis: Anatomical study comparing healed and unhealed lesions.

The anatomy and pathogenesis of spondylolysis has been widely studied; however, the microanatomy of spondylolysis of the lumbar vertebra has not been well described. Therefore, we aim to better elucidate this anatomy. Twenty dry bone specimens of healed and unhealed spondylolysis of the L5 vertebra were collected from human skeletal remains. Twelve L5 vertebrae were examples of unhealed spondylolysis and eight specimens exhibited a healed (i.e., bony fusion of the lesion) spondylolysis lesion. The specimens underwent macro and microanatomical analysis followed by CT and microCT imaging. Finally, selected healed and unhealed lesions were submitted for histological analysis using Mason Trichrome staining. The pars interarticularis of two L5 vertebrae without signs of healed/unhealed spondylolysis were evaluated histologically as controls. Of the 12 unhealed L5 pars defects, three were unilateral on left side. Of the eight healed pars defects, all were unilateral and seven of these were on left sides. One unilateral pars defect also had spina bifida occulta. Both on imaging and histological analysis, healed pars defects were only so superficially and not at deeper levels. Histologically, unhealed edges were made up of dense cortical bone while healed edges were made up primarily of trabecular bone. Based on our anatomical findings, the so-called healed spondylolysis lesions, although externally fused, are not thoroughly fused internally. Moreover, the anterior and posterior edges of the unhealed spondylosysis lesions are irregular and show signs of long-term disarticulation. Taken together, these data suggest that such 'healed' lesions might not be as stable as the normal L5 pars interarticularis.

Trabeculae in the basilar venous plexus: anatomical and histological study with application to intravascular procedures.

Few studies have examined the basilar venous plexus (BVP) and to our knowledge, no previous study has described its histology. The present anatomical study was performed to better elucidate these structures. In ten cadavers, the BVP was dissected. The anatomical and histological evaluation of the intraluminal trabeculae within this sinus were evaluated. Once all gross measurements were made, the clivus and overlying BVP were harvested and submitted for histological analysis. A BVP was identified in all specimens and in each of these, intraluminal trabeculae were identified. The mean number of trabeculae per plexus was five. These were most concentrated in the upper half of the clivus and were more often centrally located. These septations traveled in a posterior to anterior direction and usually, from inferiorly to superiorly however some were noted to travel horizontally. In a few specimens the trabeculae had wider bases, especially on the posterior attachment to the meningeal layer of dura mater. More commonly, the trabeculae ended in a denticulate form at their two terminal ends. The trabeculae were on average were 0.85 mm in length. The mean width of the trabeculae was 0.35 mm. These septations were consistent with the cords of Willis as are found in the lumen of some of the other intradural venous sinuses. An understanding of the internal anatomy of the BVP can aid in our understanding of venous pathology. Furthermore, this knowledge will benefit patients undergoing interventional treatments that involve the BVP.

Utilization of pre-operative MRI to identify AIS patients at highest risk of intra-operative neuromonitoring alert.

PURPOSE: Utility of pre-operative MRI for patients undergoing scoliosis correction has expanded to include an MRI classification for identifying patients at increased risk of experiencing intra-operative neuromonitoring (IONM) alerts based on the shape of the spinal cord and circumferential presence of CSF at the apex of the thoracic curve. In the present study, the authors explore the utility of this new MRI classification and multiple X-ray radiographic parameters in identifying the AIS sub-population at high risk of IONM alerts. METHODS: AIS patients < 18 years old who underwent posterior spinal fusion between 2018 and 2022 at a single institution. Imaging reviewed to determine main thoracic (MT) and thoraco-lumbar (TL) Cobb angles, major thoracic Apical Vertebral Translation (AVT) and lumbar/thoraco-lumbar AVT (TL AVT), thoracic kyphosis (TK), coronal main thoracic Deformity Angular Ratio (cDAR), sagittal DAR (sDAR), and MRI to determine the spinal cord type (1, 2, or 3). RESULTS: A total of 155 AIS patients who met the inclusion criteria between 2018 and 2022 were included. There was a trend to have an increased incidence of Type 3 spinal cord shape both with increase in the MT Cobb angle and MT AVT. There was also a shift toward more IONM alerts in patients with Type 3 (19.5%) spinal cords, AVT ≥ 5 cm (18.9%), and Cobb angle ≥ 650 (28.2%). CONCLUSION: Higher magnitude of thoracic Cobb angle and AVT are associated with higher likelihood of type 3 spinal cord at the apex in MRI. Patients with Type 3 spinal cord, Cobb angle ≥ 650, AVT > 5 cm, and cDAR > 10 have higher likelihood to have IONM alerts. Patient with a Type 3 spinal cord and a Cobb angle ≥ 650 (50.0%), cDAR > 10 (43.7%), and AVT > 5 cm (35.2%) have the highest risk of having IONM alerts.

Angulation Between the Occipital Condyle and the Hypoglossal Canal: An Anatomical Study With Application in Transcondylar Approaches and Occipital Condyle Screw Placement.

Background A detailed understanding of the relationship between the occipital condyle (OC) and the deeper-lying hypoglossal canal (HC) is necessary for surgeons who place screws into the OC or drill through or around the HC. Therefore, this anatomical study was performed. Methodology A total of 30 skulls (60 sides) underwent an analysis of the angle formed between the long axis of the OC and the HC, i.e., the OC/HC angle. Additionally, the lengths and widths of the OCs and foramen magnum (FM) of each skull were measured using a micrometer. Statistical analyses were performed between the left and right sides, and a Pearson's correlation coefficient was calculated between OC/HC angles and the sizes of the OCs and FM of the skulls. Results The OC/HC angle for the left and right sides ranged from 30 to 56 degrees (mean 46 degrees). The width of the OCs ranged from 9 to 18 mm (mean 13 mm). The length of the OCs was 18 to 31 mm (mean 24 mm). The mean length and width of the FM were 36 mm and 30 mm, respectively. There was no statistically significant difference between the OC/HC angle comparing left and right sides or male or female specimens. Additionally, no statistically significant differences were found between septated and non-septated HC. Pearson's correlation coefficient for left and right OC/HC angles and left and right OC lengths was r = 0.4056 and r = 0.2378, respectively. Pearson's correlation coefficient for left and right OC/HC angles and left and right OC width was r = 0.3035 and r = 0.3530, respectively. Pearson's correlation coefficient for left and right OC/HC angles and the width of the FM was r = 0.2178 and r = 0.2048, respectively. Pearson's correlation coefficient for left and right OC/HC angles and the length of the FM was r = 0.3319 and r = 0.2683, respectively. Conclusions The OC/HC angle as measured here was relatively consistent with no statistically significant differences between sides. We did not find a strong correlation between the width or length of the OC or the width or length of the FM and the OC/HC angles. Therefore, based on our study, surgeons can expect that this angle will range between 30 and 56 degrees (mean 46 degrees). Such knowledge might decrease patient morbidity following invasive procedures involving the OC.

The Échancrure of the Uncovertebral Joint: A Forgotten Structure of the C3-C7 Cervical Vertebral Bodies.

Introduction The échancrure (a French term meaning "indentation") of the cervical vertebrae is the poorly defined articular part on the inferolateral aspect of the cervical spine body, which, with the uncinate processes of the associated caudal vertebra, makes up the joints of Luschka (uncovertebral joint). With no known previous studies on the échancrure, the present anatomical study aimed to better elucidate this structure, its prevalence, and its relationships to the adjacent intervertebral foramen and uncinate process. Methods We observed 50 adult cervical spines (100 sides) for the presence of an énchancrure. When an énchancrure was identified, its morphometry was documented and photographed. Measurements included the width and height of the énchancrure. The relationship with the adjacent uncinate process was also studied. Any correlation between the size and shape of the adjacent uncinate process and the énchancrure was recorded. Results Anénchancrure was found at all levels of the cervical vertebrae except at C1 and C7 and was clearly visible on 88% of the sides. The énchancrure, more or less, conformed to the reciprocal shape of the uncinate process, which was found on all sides. The shapes were roughly arched, ovoid, or linear. These structures were always in an anterolateral position on the body of the vertebra and just outside the apophyseal ring. The mean height of the énchancrure was 2.1 mm. The length of the uncinate process correlated positively (r=0.8) to the size of the adjacent énchancrure. The height of the énchancrure was inversely related to the diameter of the adjacent intervertebral foramen. The mean width was 8.3 mm. These structures tended to be largest at C3 and C4 vertebral levels and were smallest at C5 and C6 levels. The énchancrure was most in contact with the uncinate process with lateral flexion of the cervical spine and in specimens with a longer uncinate process, e.g., C6. The énchancrure was also found to be wider in cases of cervical spine degeneration involving the body of the cervical vertebrae. Degeneration of the uncovertebral joint was most often seen at the énchancrure and not at the adjacent uncinate process. Conclusions We found that the énchancrure is found in the majority of cervical spines. These structures tended to be largest at C3 and C4 vertebral levels and were smallest at C5 and C6 levels, and they had more prominence when the adjacent uncinate process was enlarged. The énchancrure should be considered a normal feature of the inferolateral aspect of the cervical vertebrae. Future clinical studies are necessary to better elucidate their functional significance.

Management of severe traumatic flexion-distraction injuries in a multisystem trauma patient: A case report.

STUDY DESIGN: Case report and relevant literature review. OBJECTIVE: To discuss the management of severe flexion-distraction injury of the subaxial cervical spine in a multisystem trauma patient. SUMMARY OF BACKGROUND DATA: Traumatic cervical spine injury from flexion-distraction injury can cause significant instability requiring extensive instrumentation complicated by vascular and soft tissue injuries. METHODS: The medical record of a patient who suffered traumatic flexion-distraction injury was reviewed for relevant clinical and radiology data. A literature review on the management of traumatic cervical injuries was performed using the PubMed database. RESULTS: We report a case of 21-year-old woman who suffered a C5-C6 flexion-distraction injury. After she underwent anterior cervical discectomy and fusion (ACDF), her care was transferred to the senior author (S.K.) due to the severity of the distraction. The patient returned to the OR the next day and underwent removal of implants at C5 and corpectomy with anterior and posterior instrumentation. CONCLUSION: There are many ways to manage a flexion-distraction injury of the cervical spine. In a polytrauma patient, the surgical strategy can become complex. We present a surgical option with an acceptable outcome.

Thermal properties of contemporary bipolar systems using infrared imaging.

BACKGROUND: Bipolar coagulation has enhanced the capabilities and safety profile of contemporary neurosurgery and has become indispensable in the neurosurgical armamentarium. Nevertheless, significant heat transfer issues remain to be resolved before it can achieve the status of minimal risk. METHODS: The Codman irrigating forceps, Codman ISOCOOL forceps, and Ellman bipolar forceps, powered by either Synergy or Ellman generators set at various power levels, were compared to investigate the combinations that would allow for the lowest rate of heat transfer. Using an infrared camera and ThermaGRAM imaging software, the temperature was calculated and used to estimate the degree of heat transfer. RESULTS: Codman ISOCOOL forceps powered the Ellman Surgitron generator showed the greatest dissipation (at mid-power, the luminance decreased from 250 units to 80 units within 60 seconds) and the least production of heat after activation. Codman ISOCOOL forceps powered by the Codman SYNERGY MALIS generator showed less heat dissipation (at mid-power, the luminance decreased from 250 units to 195 units within 60 seconds) than the Ellman forceps and Ellman Surgitron generator combination (at mid-power, the luminance decreased from 250 units to 125 units within 60 seconds). CONCLUSIONS: These data suggest that the incorporation of the Ellman Surgitron Generator can result in the reduction of thermal transfer with conventional bipolar forceps compared with other generators. The combination with Codman ISOCOOL forceps can maximize the potential safety associated with bipolar coagulation. With regard to the use of comarketed pairs of forceps and generators, the combination of Ellman Surgitron Generator and Ellman bipolar forceps provided the best thermal profile.

Clinical experience with the surgicel family of absorbable hemostats (oxidized regenerated cellulose) in neurosurgical applications: a review.

INTRODUCTION: Oxidized regenerated cellulose has a long history of safe and effective use in the surgical setting. Surgicel Original, Fibrillar and Nu-Knit absorbable hemostats are composed of oxidized regenerated cellulose and are sterile, absorbable knitted fabrics that are flexible and adhere readily to bleeding surfaces. The purpose of this paper is to discuss neurosurgical applications for these absorbable hemostatic agents. METHODS: The authors reviewed the literature and described their clinical experience with Surgicel hemostatic products. RESULTS: Neurosurgical applications of the hemostatic products include the management of diffuse capillary oozing following bipolar cautery in brain tumor resection beds and the control of epidural oozing during spinal surgery. As an adjunct to standard hemostatic procedures, these products facilitate rapid hemostasis and have bactericidal activity that extend to antibiotic-resistant organisms such as methicillin-resistant Staphylococcus aureus, Staphylococcus epidermidis, and Streptococcus pneumonia, as well as Pseudomonas aeruginosa. Although generally safe and well-tolerated, these hemostatic agents should be removed when used around, in, or in proximity to, foramina in bone, areas of bony confine, the spinal cord, and/or the optic nerve or chiasm because it may otherwise swell and cause unwanted pressure. CONCLUSION: The physical, hemostatic, and bactericidal characteristics of this material makes it a useful adjunct for conventional hemostatic and controlling capillary, venous, and small arterial hemorrhage during neurosurgery. .

Perioperative Outcomes and Complications of Pedicle Subtraction Osteotomy in Cases With Single Versus Two Attending Surgeons.

STUDY DESIGN: Retrospective case series. OBJECTIVE: To assess the perioperative morbidity of pedicle subtraction osteotomy (PSO) based on the presence of 1 versus 2 attending surgeons. BACKGROUND SUMMARY: Pedicle subtraction osteotomies are challenging cases with high complication rates and substantial physiological burden on patients. The literature supports the benefits of 2-surgeon strategies in complex cases in other specialties. METHODS: We reviewed a single institution database of all pedicle subtraction osteotomies (78 cases) from 2005-2010 and divided the cohort into single versus 2-surgeon groups (42 vs. 36 cases, respectively). We performed subset analysis after excluding cases before 2007 and excluding patients with staged anterior and posterior procedures. We analyzed cases for estimated blood loss, length of surgery, length of stay, radiographic analysis, rate of return to the operating room within 30 days, and medical and neurological complications. RESULTS: The groups were similar when comparing mean number of posterior levels fused, levels decompressed and revision rates, however, the average age of the single surgeon and 2 surgeon groups was 57.6 and 64.3 years, respectively (p = .02). The 2 groups had comparable correction of radiographic parameters. Mean percent estimated blood loss for single versus 2 surgeons was 109% versus 35% (p < .001) and estimated blood loss was 5,278 versus 2,003 mL (p < .001). Average surgical time for single versus 2 surgeons was 7.6 versus 5.0 hours (p < .001). A total of 45% of single-surgeon patients compared with 25% of 2-surgeon patients experienced at least 1 major complication within 30 days. In the single-surgeon group, 19% had unplanned surgery within 30 days, versus 8% in the 2-surgeon group. CONCLUSIONS: The use of 2 surgeons at an experienced spine deformity center decreases the operative time and estimated blood loss, and may be a key factor in witnessed decreased major complication prevalence. This approach also may decrease the rate of premature case termination and return to operating room in 30 days.

Assessment of symptomatic rod fracture after posterior instrumented fusion for adult spinal deformity.

BACKGROUND: Improved understanding of rod fracture (RF) in adult spinal deformity could be valuable for implant design, surgical planning, and patient counseling. OBJECTIVE: To evaluate symptomatic RF after posterior instrumented fusion for adult spinal deformity. METHODS: A multicenter, retrospective review of RF in adult spinal deformity was performed. Inclusion criteria were spinal deformity, age older than 18 years, and more than 5 levels posterior instrumented fusion. Rod failures were divided into early (≤12 months) and late (>12 months). RESULTS: Of 442 patients, 6.8% had symptomatic RF. RF rates were 8.6% for titanium alloy, 7.4% for stainless steel, and 2.7% for cobalt chromium. RF incidence after pedicle subtraction osteotomy (PSO) was 15.8%. Among patients with a PSO and RF, 89% had RF at or adjacent to the PSO. Mean time to early RF (63%) was 6.4 months (range, 2-12 months). Mean time to late RF (37%) was 31.8 months (range, 14-73 months). The majority of RFs after PSO (71%) were early (mean, 10 months). Among RF cases, mean sagittal vertical axis improved from preoperative (163 mm) to postoperative (76.9 mm) measures (P<.001); however, 16 had postoperative malalignment (sagittal vertical axis>50 mm; mean, 109 mm). CONCLUSION: Symptomatic RF occurred in 6.8% of adult spinal deformity cases and in 15.8% of PSO patients. The rate of RF was lower with cobalt chromium than with titanium alloy or stainless steel. Early failure was most common after PSO and favored the PSO site, suggesting that RF may be caused by stress at the PSO site. Postoperative sagittal malalignment may increase the risk of RF.

A single spinal lesion arising from an intradural meningioma contiguous with an extradural lymphoma.

The authors describe here a unique case of contiguous, synchronous meningioma and lymphoma in the spinal column. Both tumors were present at the same vertebral level, one intradural and the other extradural. A patient presented with bilateral leg pain, acute weakness, and sensory loss in the lower extremities. Magnetic resonance imaging revealed an intradural mass at T6-7 with ambiguous boundaries relative to the thecal sac and compressing the spinal cord. The patient underwent resection of the epidural and intradural mass at T6-7. Histopathology revealed the epidural specimen to be a double-hit B-cell lymphoma and the intradural mass to be a transitional meningioma. Postoperatively, the patient did well, with an immediate return of strength and sensation. A postoperative MR image showed complete resection of the intradural mass. The authors suggest that biopsy may be prudent in patients with known systemic lymphoma presenting with a spinal lesion that has unclear boundaries relative to the thecal sac prior to commencing radiation and chemotherapy.

Chronic spinal compression model in minipigs: a systematic behavioral, qualitative, and quantitative neuropathological study.

The goal of the present study was to develop a porcine spinal cord injury (SCI) model, and to describe the neurological outcome and characterize the corresponding quantitative and qualitative histological changes at 4-9 months after injury. Adult Gottingen-Minnesota minipigs were anesthetized and placed in a spine immobilization frame. The exposed T12 spinal segment was compressed in a dorso-ventral direction using a 5-mm-diameter circular bar with a progressively increasing peak force (1.5, 2.0, or 2.5 kg) at a velocity of 3 cm/sec. During recovery, motor and sensory function were periodically monitored. After survival, the animals were perfusion fixed and the extent of local SCI was analyzed by (1) post-mortem MRI analysis of dissected spinal cords, (2) qualitative and quantitative analysis of axonal survival at the epicenter of injury, and (3) defining the presence of local inflammatory changes, astrocytosis, and schwannosis. Following 2.5-kg spinal cord compression the animals demonstrated a near complete loss of motor and sensory function with no recovery over the next 4-9 months. Those that underwent spinal cord compression with 2 kg force developed an incomplete injury with progressive partial neurological recovery characterized by a restricted ability to stand and walk. Animals injured with a spinal compression force of 1.5 kg showed near normal ambulation 10 days after injury. In fully paralyzed animals (2.5 kg), MRI analysis demonstrated a loss of spinal white matter integrity and extensive septal cavitations. A significant correlation between the magnitude of loss of small and medium-sized myelinated axons in the ventral funiculus and neurological deficits was identified. These data, demonstrating stable neurological deficits in severely injured animals, similarities of spinal pathology to humans, and relatively good post-injury tolerance of this strain of minipigs to spinal trauma, suggest that this model can successfully be used to study therapeutic interventions targeting both acute and chronic stages of SCI.

Expandable titanium cages for thoracolumbar vertebral body replacement: initial clinical experience and review of the literature.

Reconstruction of the anterior and middle column after vertebrectomy is essential for restoring stability. Use of expandable implants is supported by an emerging body of literature. Newer expandable cages have some advantages over traditional mesh implants, structural allograft, and polyetheretherketone or carbon fiber cages. To determine the utility of an expandable titanium cage in spine reconstruction, we conducted a retrospective cohort study of patients who had undergone this reconstruction after single or multilevel thoracic and/or lumbar vertebrectomy. Here we report on our experience using expandable cages at 2 large academic medical centers. Outcome was based on both clinical and radiographic measures with cross-sectional analysis. Thirty-five patients were identified. Of these, 20 had undergone surgery for neoplasm, 8 for trauma, and 7 for infection. Mean follow-up was 31 months (range, 12 to 50 months). Early postoperative kyphosis correction, restoration of sagittal alignment at 12 months, and reduction in visual analog scale pain score were significant. There was no difference in Oswestry Disability Index or height restoration. Expandable intervertebral body strut grafts appear to be a safe and effective option in spine reconstruction after a vertebrectomy and should be considered a treatment option.

The risk of growing skull fractures in craniofacial patients.

BACKGROUND/AIMS: Growing skull fractures (GSFs) are unusual sequelae of head injury in young children which have also been reported to occur after craniofacial procedures complicated by inadvertent durotomy. We reviewed the craniofacial experience in a single institution, detailing 180 cases of craniofacial surgery and suspected dural tears and their relationship to the subsequent development of GSFs. This experience was then compared to that of the pertinent published literature. METHODS: A retrospective review of the senior authors' craniofacial surgical experience from 2000 to 2007 was performed. This was compared to an English-language literature review of GSFs after craniofacial surgery. RESULTS: In our institution, 180 cases of craniofacial surgery (83 open, 97 endoscopic) were performed, with an average follow-up of 23.5 months. Twenty-five patients (15 open, 10 endoscopic surgeries) had operative dural compromise. One of these patients developed a persistent pseudomeningocele requiring reoperation. Twelve cases of GSF after craniofacial surgery were identified in a review of the English-language literature, of which 7 (58%) had coronal suture fusion. CONCLUSIONS: While durotomy may occur during craniofacial surgery, the subsequent development of a GSF appears to be an unlikely event with an aggressive intraoperative approach of identification and repair. Coronal craniosynostosis may confer an increased risk for this complication.

Exploitation of genetically modified neural stem cells for neurological disease.

The successful treatment and potential treatment of the central nervous system (CNS) pathology remains the most challenging frontier in medical science. The clinical modalities presently available are mostly of limited efficacy and with the aging population, neurodegerative diseases and CNS neoplasms are increasingly prevalent. Neural stem cells (NSCs) have provided optimism for the horizon of therapeutic progress in treating neurological diseases. These mutipotent (able to differentiate into neurons, astrocytes and oligodendrocytes) cells can be obtained directly from the CNS or derived from of embryonic stem cells (ESCs). NSCs can be genetically manipulated in vitro to express desired transgenes for improved expandability, as well as for delivery of toxic payloads. NSCs also demonstrate the ability to engraft within the CNS, migrate to CNS pathology and in certain scenarios to reconstitute the injured or diseased nervous system.

Variations of endoscopic and open repair of metopic craniosynostosis.

In contrast to sagittal craniosynostosis, the role of endoscopic, minimally invasive approaches in the treatment of metopic craniosynostosis with resulting trigonocephaly is not as well defined. We reviewed the senior authors' (H.M. and S.C.) clinical experience in the treatment of children with metopic craniosynostosis using a variety of endoscopic and open techniques. Thirty-three patients were treated at a single institution during a 5-year period with between 3 and 8 years of follow-up. Sixteen patients underwent 3 variations of endoscopic approaches, and 17 patients had open fronto-orbital advancement. Clinical parameters of the 2 groups were examined including age at surgery, blood loss, operative time, transfusion volume, hospital stay, complications, use of postoperative cranial banding, and the need for reoperation for persistent deformity. The various endoscopic and open techniques used by the authors in the treatment of metopic craniosynostosis are discussed in detail, including rational for individual technique selection and preliminary impressions regarding clinical outcome.