Minimally Invasive Microscope-Assisted Stand-Alone Transarticular Screw Fixation without Gallie Supplementation in the Management of Mobile Atlantoaxial Instability.

STUDY DESIGN: Retrospective study. PURPOSE: To evaluate the clinico-radiological efficacy of stand-alone minimally invasive transarticular screw (MIS-TAS) fixation without supplemental Gallie fixation in the management of mobile C1-C2 instability. OVERVIEW OF LITERATURE: Data evaluating the efficacy and feasibility of MIS-TAS in the literature is scanty. METHODS: Patients with mobile atlantoaxial instability and >2 years follow-up were included and managed by stand-alone TAS fixation using the Magerl technique and morselized allograft without additional fixation. Patient demographics and intra-operative parameters were noted. Clinical parameters (Visual Analog Scale [VAS] and Oswestry Disability Index [ODI]), neurology (modified Japanese Orthopaedic Association [mJOA]), and radiological factors (anterior atlanto-dens interval and space available for cord) were evaluated pre and postoperatively. Computed tomography (CT) was performed in patients who did not show interspinous fusion on X-ray at 1 year, to verify intra-articular fusion. Statistical analysis was performed using IBM SPSS ver. 20.0 (IBM Corp., Armonk, NY, USA); the Student t -test and analysis of variance were used to assess statistical significance (p <0.05). RESULTS: A total of 82 consecutive cases (three males, one female; mean age, 36.26±5.78 years) were evaluated. In total, 163 TASs were placed. Significant improvement was noticed in clinical (mean preoperative VAS=7.2±2.19, postoperative VAS=3.3±1.12; mean preoperative ODI=78.3±4.83, postoperative ODI=34.05±3.26) and neurological features (mean preoperative mJOA=14.73±2.68, postoperative mJOA=17.5±2.21). Radiological evidence of fusion was noted in 97.5% cases at final follow-up. Seventeen patients were found to have no interspinous fusions upon X-rays, but CT revealed facet fusion in all patients except in two. Inadvertent vertebral artery injury was noted in three cases. CONCLUSIONS: Stand-alone TAS fixation with morselized allograft provides excellent radiological and clinical outcomes. The addition of a supplementary tension band and structural graft are not essential. This provides the opportunity to avoid the complications associated with graft harvesting and wiring.

Comparative Prospective Study Reporting Intraoperative Parameters, Pedicle Screw Perforation, and Radiation Exposure in Navigation-Guided versus Non-navigated Fluoroscopy-Assisted Minimal Invasive Transforaminal Lumbar Interbody Fusion.

STUDY DESIGN: Prospective cohort study. PURPOSE: To compare intraoperative parameters, radiation exposure, and pedicle screw perforation rate in navigation-guided versus non-navigated fluoroscopy-assisted minimal invasive transforaminal lumbar interbody fusion (MIS TLIF). OVERVIEW OF LITERATURE: The poor reliability of fluoroscopy-guided instrumentation and growing concerns about radiation exposure have led to the development of navigation-guided instrumentation techniques in MIS TLIF. The literature evaluating the efficacy of navigation-guided MIS TLIF is scant. METHODS: Eighty-seven patients underwent navigation- or fluoroscopy-guided MIS TLIF for symptomatic lumbar/lumbosacral spondylolisthesis. Demographics, intraoperative parameters (surgical time, blood loss), and radiation exposure (sec/mGy/Gy.cm2 noted from C-arm for comparison only) were recorded. Computed tomography was performed in patients in the navigation and non-navigation groups at postoperative 12 months and reviewed by an independent observer to assess the accuracy of screw placement, perforation incidence, location, grade (Mirza), and critical versus non-critical neurological implications. RESULTS: Twenty-seven patients (male/female, 11/16; L4-L5/L5-S1, 9/18) were operated with navigation-guided MIS TLIF, whereas 60 (male/female, 25/35; L4-L5/L5-S1, 26/34) with conventional fluoroscopy-guided MIS TILF. The use of navigation resulted in reduced fluoroscopy usage (dose area product, 0.47 Gy.cm2 versus 2.93 Gy.cm2), radiation exposure (1.68 mGy versus 10.97 mGy), and fluoroscopy time (46.5 seconds versus 119.08 seconds), with p-values of <0.001. Furthermore, 96.29% (104/108) of pedicle screws in the navigation group were accurately placed (grade 0) (4 breaches, all grade I) compared with 91.67% (220/240) in the non-navigation group (20 breaches, 16 grade I+4 grade II; p=0.114). None of the breaches resulted in a corresponding neurological deficit or required revision. CONCLUSIONS: Navigation guidance in MIS TLIF reduced radiation exposure, but the perforation status was not statistically different than that for the fluoroscopy-based technique. Thus, navigation in nondeformity cases is useful for significantly reducing the radiation exposure, but its ability to reduce pedicle screw perforation in nondeformity cases remains to be proven.

Posterior-approach single-level apical spinal osteotomy in pediatric patients for severe rigid kyphoscoliosis: long-term clinical and radiological outcomes.

OBJECTIVE Spinal osteotomy in pediatric patients is challenging due to various factors. For correction of severe rigid kyphoscoliosis in children, numerous techniques with anterior or posterior or combined approaches, as well as multilevel osteotomies, have been described. These techniques are associated with prolonged operative times and large amounts of blood loss. The purpose of this study was to evaluate the clinical and radiologically confirmed efficacy of a modification of the apical spinal osteotomy (ASO) technique-posterior-only single-level asymmetric closing osteotomy-in pediatric patients with severe rigid kyphoscoliosis. METHODS The authors performed a retrospective study of a case series involving pediatric patients with severe spinal deformity operated on by a single surgeon at a single institution over a period of approximately 5 years. The inclusion criteria were age < 14 years, rigid thoracic/thoracolumbar/lumbar kyphosis (> 70°) with or without neurological deficit and with or without scoliosis, and a minimum of 2 years of follow-up. Patients with cervical or lumbosacral kyphoscoliosis were excluded from the study. Demographic and clinical parameters, including age, sex, etiology of kyphoscoliosis, neurological examination status (Frankel grade), and visual analog scale (VAS) and Oswestry Disability Index (ODI) scores, were noted. Operative parameters (level of osteotomy, number of levels fused, duration of surgery, blood loss, and complications) were also recorded. Radiological assessment was done for preoperative and postoperative kyphosis and scoliosis as well as the final Cobb angle. Similarly, sagittal vertical axis (SVA) correction was calculated. Fusion was assessed in all patients at the final follow-up evaluation. RESULTS A total of 26 pediatric patients (18 male and 8 female) with a mean age of 9 years met the inclusion criteria and had data available for analysis, and all of these patients had severe scoliosis as well as kyphosis. Comparison of preoperative and postoperative values showed a significant improvement (p < 0.05) in radiological, clinical, and functional parameters (Cobb angle for scoliosis and kyphosis, SVA, VAS, and ODI). With respect to kyphosis, the mean preoperative Cobb angle was 96.54°, the mean postoperative angle was 30.77°, and the mean angle at final follow-up was 34.81° (average loss of correction of 4.23°), for a final average correction of 64.15%. With respect to scoliosis, the mean preoperative angle was 52.54°, the mean postoperative angle was 15.77°, and the mean angle at final follow-up was 19.42° (average loss of correction of 3.66°), for a final average correction of 60.95%. The preoperative SVA averaged 7.6 cm; the mean SVA improved to 3.94 cm at the end of 2 years. Bony fusion was achieved in all patients. The mean number of levels fused was 5.69. The mean operative time was 243.46 minutes, with an average intraoperative blood loss of 336.92 ml. Nonneurological complications occurred in 15.39% of patients (2 dural tears, 1 superficial infection, 1 implant failure). At the 2-year follow-up, 25 of the 26 patients had maintained or improved their neurological status. One patient developed paraplegia immediately after the operation and recovered only partially. CONCLUSIONS Analysis of data from this series of 26 cases indicates that this posterior-approach single-level technique is effective for the correction of severe rigid kyphoscoliosis in pediatric patients, providing good clinical and radiological results in most cases.

Feasibility and outcome of stand-alone trans-articular screw fixation in atlantoaxial instability in children less than 8 years of age.

PURPOSE: To study the feasibility and outcome of stand-alone trans-articular screw (TAS) fixation for atlantoaxial instability (AAI) in children less than 8 years of age. METHODS: This prospective study was conducted between 2009 and 2014. Thirteen children suffering from AAI were operated for a TAS fixation. Feasibility of TAS fixation was assessed on CT scan and a screw diameter was chosen based on C2 isthmus diameter. Demographic data collected included the etiology for AAI, age, and sex. Intra-operative data recorded was the duration of surgery, blood loss, vertebral artery injury or any adverse event. Radiological evaluation included pre- and post-operative atlantodens interval (ADI) and space available for cord (SAC) and fusion was evaluated at 3, 6, 12 and 24 months. Statistical analysis was done using SPSS software and statistical significance was set at p < 0.05. RESULTS: The mean age of the final study group was 6.1 ± 1.5 years, with nine males and four females. Mean isthmus diameter on the left and right side was 3.3 ± 0.3 and 3.2 ± 0.2 mm, respectively. Five patients had an isthmus diameter of < 3.2 mm and a 2.7 mm Herbert screw was used in them and in nine patients, a CCS of 3.2 mm was used. Mean pre- and post-op ADI and SAC improved from 5.5 ± 0.8 to 3.1 ± 0.1 mm, respectively, and 9.8 ± 2.8 to 14 ± 0.6 mm, respectively. Fusion was seen in all patients. CONCLUSIONS: Stand-alone TAS with morselized allograft is safe, feasible and successful in managing AAI in children below 8 years of age. These slides can be retrieved under Electronic Supplementary Material.

An unusual case of intradural intramedullary dorsal bronchogenic cyst in spine.

Bronchogenic cysts are congenital malformations derived from anomalous budding of the embryonic foregut. Intraspinal bronchogenic cysts are extremely rare and most of them are extramedullary. There has been only one case of intramedullary spinal bronchogenic cyst reported. We present an 18-year-old male patient with spastic paraparesis and bowel and bladder involvement. MRI revealed a 2 cm diameter intradural and intramedullary lesion at D2-D3 level which was hyperintense on T1 and hypointense on T2 imaging. Histopathological examination after surgical excision of the lesion revealed a bronchogenic cyst. To our knowledge this is the first case reporting an intramedullary bronchogenic cyst at the upper dorsal level and overall second reported case of intramedullary spinal bronchogenic cyst.

Schwannoma of the Median Nerve at Mid Forearm Level.

INTRODUCTION: Schwannomas are also known as neurilemmoma that usually originate from Schwann cells located in the peripheral nerve sheaths. It usually occurs in the age group of 20 to 70 years. These are the commonest tumors of the peripheral nerves, 5% of which occur in the adults and 19% of the tumors occur in upper extremities. Schwannomas are generally presented as an asymptomatic mass. Discomfort may be the only presenting complaint of the patient. Paresthesia may be elicited on tapping the swelling. Magnetic resonanceimaging, and ultrasound are helpful in the diagnosis. Surgical removal is usually curative. CASE PRESENTATION: A 28-year-old male came to our hospital for a lump located at the volar side of the right mid forearm for 10 years with discomfort and paresthesia in median nerve distribution of hand which appeared in last two years. Total excision was performed for the lesion. Histopathological examination of the mass revealed typical features of schwannoma. At two months follow-up, the patient was symptom free with mild paresthesia in his index and middle fingers. CONCLUSION: Benign tumours involving peripheral nerves of the upper extremity are uncommon. Schwannomas are theoretically removable because they repulse fascicular groups without penetrating them, thus allowing their enucleation while preserving nerve continuity, as reported in our patient.