"Critical pedicle wall" breaches analysis in complex spinal deformity using O-arm navigation.

Background: Free-hand and fluoroscopic-guided pedicle screw placement has been associated with higher rates of pedicle breaches (frequency range 15-40% especially in deformed pedicles). Neurological complications are more "critical" (i.e., frequent and significant) with medial and inferior pedicle-wall breaches due to the proximity of the neural elements. Here, we analyzed the effectiveness of O-arm navigation in minimizing "critical" pedicle wall breaches and their complications in 21 complex spinal deformity cases. Methods: Twenty-one complex spinal deformity cases were prospectively managed with O-arm-navigated posterior-instrumented fusions. Preoperative assessment included; evaluation of the type of scoliosis, the magnitude of the deformity, and the anatomy of the pedicles - (i.e., classified using Watanabe et al.). The O-arm was used to confirm and grade both the intraoperative and postoperative location of screws. Other variables analyzed included; duration of surgery, estimated blood loss, complications, and radiation exposure. Results: In 21 patients, 259 (63.45%) of 384 pedicles were instrumented; we observed 22 of 259 pedicle screw breaches. Significant (>2 mm) breaches were observed in two medial and one inferior wall cases that required revision; the overall biomechanically significant screw breach rate was (3/259) 1.2% with an accuracy rate of 98.8%. Pedicle screw placement resulted in another 14 nonsignificant (<2 mm) breaches; ten were medial and four involved the inferior wall. As anterior, lateral, and "in-out-in" trajectory pedicle screws beaches were nonsignificant, they were not included in our analysis. Conclusion: O-arm navigation decreased the incidence of medial and inferior (i.e., >2 mm "critical") pedicle screw breaches applied in 21 patients with deformed pedicles due to scoliosis. Further, the O-arm minimized the operating time, decreased the estimated blood loss, and reduced the incidence of complications.

Learning curve across 2000 thoracolumbar pedicle screw placements using O-arm navigation: technical difficulties and their solutions.

INTRODUCTION: Instrumentation using the intraoperative O-arm navigation technique appears safer than its predecessor techniques. However, only a handful of surgeons often used navigation during spinal surgeries. Too many operative glitches and unreliable navigation accuracy were the important reasons cited even by experienced surgeons for not using spinal navigation. We have studied the accuracy of pedicle screw placement during the learning curve and beyond it. We have also discussed in detail the intricacies of the technique and solutions to the difficulties encountered using spinal navigation. MATERIALS AND METHODS: A total of 2000 thoracolumbar pedicle screws have been placed in the 324 spine surgeries meeting the inclusion and exclusion criteria included in this retrospective study. We have divided 2000 pedicle screw placements into consecutive groups of 200 each. We have compared these groups for the accuracy of screw placement with the surgeon's experience. RESULTS: The accuracy of pedicle screw placement using the "in-versus-out" grading system in group 1 was 85.5% which significantly increased in group 2 to 93.5% (p-value: 0.0099), and thereafter, there was a nonsignificant increase in subsequent groups with the graph achieving the shape of a plateau. CONCLUSION: Surgeons should learn the correct principles of the technique of O-arm navigation to prevent the loss of accuracy and place pedicle screws with high accuracy. There is a learning curve of around 30-35 surgeries or 200 pedicle screw placements to acclimatize with the technique of O-arm navigation and learn its principles.

O-arm Navigated en bloc Excision of a Solitary Subaxial Cervical Osteochondroma Presenting as Myelo-radiculopathy: A Case Report.

Introduction: Vertebral osteochondroma is a rare entity. It presents with varied complaints ranging from palpable mass to myeloradiculopathy. En bloc excision is the gold standard treatment option for symptomatic patients. Real-time intraoperative navigation has increased the accuracy and safety of tumor excision. We report a case of cervical subaxial osteochondroma with myelo-radiculopathy, treated with excision, and monosegmental fusion under O-arm-based real-time navigation. Case Report: A 32-year-old male presented with complaints of axial neck pain with the right upper limb radiculopathy for 18 months. On examination, signs of myelopathy were identified without sensory-motor deficit. Magnetic resonance imaging and computed tomography scans were suggestive of solitary C6 osteochondroma compressing spinalcord. O-arm navigated en-bloc tumor excision with C5 hemilaminectomy and monosegmental fusion was done. Conclusion: The use of O-arm navigation aids in accurate intraoperative en bloc excision without any residual tumor and with better safety.

Efficacy of less Invasive modified O-arm navigated delta fixation in osteoporotic high-grade spondylolisthesis: "a LIMO delta technique".

PURPOSE: In 1994, the technique of transdiscal screws fixation in spondylolisthesis was introduced but did not gained popularity as it failed to address problems with spinal sagittal imbalance, retroverted pelvis, pseudoarthrosis, implant failure and neural injury. Majority of problems were due to lack of clear indications; hence, in this study, with modification of traditional technique and use of O-arm navigation for selected group of patients, we have addressed the above problems and given good to excellent functional outcomes. METHODS: We did prospective study on 15 patients with osteoporotic high-grade spondylolisthesis Meyerding grade 3 & 4 admitted in period 2020-2021. Intraoperative assessment was done in form of blood loss, incision length, operative time and complications. The preoperative & postoperative assessment was done in the form of clinical and radiological parameters. RESULTS: The average follow-up was of 21.2 months (18-24 months). There was no significant difference between pre- & postoperative spinopelvic parameters. Intraoperative average blood loss was 100 ml (90-120 ml) with mean surgical time of 138 min (120-150 min). Incision length was about 5-6-cms-posterior midline with two paraspinal 1-cm incisions for transdiscal screws. Patients were mobilized on postoperative day-2. There was statistically significant improvement in mean ODI, COMI and VAS for LBP and radicular pain with no intra- or postoperative complication observed till latest follow-up with all patients showing solid monoblock fusion on 1-year follow-up CT scan. CONCLUSIONS: LIMO delta technique is a newly modified version of conventional transdiscal screw technique. Minimal incision, decreased blood loss & operative time with in situ 3-column rigid fixation and solid fusion minimizing risk of complications makes this novel technique safer, simpler & effective in osteoporotic HGS.

Utility of selected sequence MRI imaging of the axial skeleton in the diagnosis of axial spondyloarthritis.

Background: Whole body MRI has been used to evaluate inflammatory lesions associated with axial spondyloarthritis (SpA). These sequences are extensive, time consuming and add to the cost of the investigation. We aimed to determine the utility of selected sequence MRI imaging of the axial skeleton including spine, pelvis and sacroiliac (SI) joints to identify features of (SpA). Methods: A retrospective study was conducted on 76 patients diagnosed with SpA that underwent a selective sequence MRI imaging of the axial skeleton. The MRI were reported by two musculoskeletal trained radiologists were reviewed. The MRI sequences included whole spine sequences of sagittal STIR (short tau inversion recovery), T1 weighted and T2 weighted sequences. Coronal STIR and T1 weighted images were studied for SI joints and pelvis. The MRI were assessed based on the guidelines outlined by the Assessment of SpondyloArthritis International Society (ASAS) for features of spondylitis, spondylodiscitis, enthesitis, synovitis, capsulitis, bone marrow edema, fatty marrow replacement, erosions and bony ankylosis. Inflammatory lesions were documented in the spine, sacroiliac, facet, hip and costovertebral joints. Results: The mean scan duration was 28 min. SI joint involvement was noted in 74 (97.3%) of patients. The other most prevalent findings were spondylitis in 44 (57.8%) patients, costovertebral joint involvement in 31 (40.7%), facet joint lesions in 32 (42.1%), spondylodiscitis in 21 (27.6%), enthesitis in 13 (17.1%), hip lesions in 16 (21%) and ankylosis in 10 (13.1%). Conclusions: This selective sequence imaging of the pelvis and spine was able to identify typical lesions of SpA in a shorter time period. Fifty-five percent patients had lesions in the posterior elements including facet joints and costovertbral joints that would be missed on traditional SI joint imaging.

Standalone cage versus anchored cage for anterior cervical discectomy and fusion: a comparative analysis of clinical and radiological outcomes.

PURPOSE: The use of standalone cages (SAC) and anchored cages (AC) in anterior cervical discectomy and fusion surgery (ACDF) has shown advantage of reduced operative time and lower incidence of dysphagia. However, there is limited literature available comparing the clinical and radiological outcomes of SAC and AC. METHODS: We conducted a prospective study for patients undergoing ACDF for cervical radiculopathy or myelopathy. Patient were classified based on the cage used into SAC group and the AC group. Clinical outcomes were assessed using the modified Japanese Orthopedic Association (mJOA) for myelopathy and Neck Disability Index (NDI) and Visual Analogue Scale (VAS) for radiculopathy. Dysphagia was graded as per Bazaz score. Radiologically, global cervical lordosis, segmental lordosis, cage subsidence, and migration were assessed. RESULTS: We analyzed 31 patients in each group with a minimum two year follow-up. The mean VAS improved from 7.9 to 4.56, mean NDI score improved from 27.6 to 19.8, and mean mJOA improved from 10.8 to 11.7 which were statistically significant (p < 0.05); however, no significant difference was noted between the SAC and AC groups. Mean global lordosis improved from 14.4 to 20.3° and mean segmental lordosis improved from 6 to 10.1° at six months and plateaued to 6.9° at final follow up without any significant difference between the groups. The subsidence was statistically more in 12.9% (4/31) in SAC than 6.4% (2/31) in AC. CONCLUSION: AC showed of lower rates of subsidence while both SAC and AC had comparable clinical outcomes and radiological alignment outcomes.

Less invasive O-arm navigation-guided excision of thoracic extraosseous intraforaminal osteoblastoma: A case report.

Background: Gross-total excision of spinal osteoblastomas remains challenging as they are typically found in close proximity to major neural and/or vascular structures. Here, we found that O-arm navigation allowed for safe/effective excision of a spinal osteoblastoma in a 29-year-old male. Case Description: A 29-year-old male presented neurologically intact with mid back pain of 8 months' duration and 2 months of the left-sided chest wall discomfort. X-rays showed a sclerotic left D12 pedicle, while the MRI revealed an extradural lesion in extending into the left D11-12 neural foramen (i.e., hypointense on both T1- and T2-weighted images). The CT scan suggested a "floating" foraminal radiolucent lesion with surrounding vertebral body/posterior elements sclerosis and dense peripheral rim enhancement. These findings were diagnostic for an osteoblastoma. Utilizing O-arm navigation, the nidus and full extent of the lesion were excised (i.e., utilizing intralesional curettage). Two year's postoperatively, there was no MR evidence of tumor recurrence. Conclusion: O-arm navigation provided accurate intraoperative localization to safely and fully excise a left D11- D12 spinal osteoblastoma.

Emergently Managed Rare Case of Extraosseous Hemorrhagic Spinal Epidural Cavernous Hemangioma: A Case Report.

Introduction: Commonly spinal cavernous hemangioma (CH) is found in vertebral body at thoracic level. Purely extraosseous epidural CH contributes only 4% of all CH. In addition, these patients usually present in their 3rd-6th decade of life. Here, we report emergently treated rare case of hemorrhagic extraosseous epidural thoracic CH in a 26-year-old male. Case Report: A 26-year-old male presented with inability to walk without support with acute onset paraparesis and hypoesthesia below D7 with positive myelopathy signs. Magnetic resonance imaging showed posterior epidural well-defined homogenous mass from D6-8 region. PET scan ruled out other primary lesions in body. Intraoperative after D6-8 laminectomy extradural vascular mass was found which was bleeding on touch. With adequate hemostasis complete mass was excised and sent for sampling which revealed CH. The patient showed gradual clinical recovery with complete neurological recovery after 3 months with no signs of clinical and radiological recurrence on 2 years of follow-up. Conclusion: Extraosseous epidural CH is very rare presentation; hence, the differentials of schwannoma, lymphoma, tubercular/pyogenic epidural abscess, metastasis, and others must always be ruled out. They can present a decade earlier in a case of hemorrhagic CH with rapid progressive neurological deficit which warrants early surgical decompression like in our case and the foraminal or paravertebral extension needs foraminotomy or thoracotomy for complete excision.

Recurrent solitary bone plasmacytoma: A case report.

BACKGROUND: Plasmacytoma is an hematological malignancy that originates in bone. It may involve a single skeletal location. Notably, these lesions can progress to involve multiple segments in 50% of cases, at which point they are classified as having multiple myeloma (MM). CASE DESCRIPTION: One year ago, this patient had undergone a D6 laminectomy and biopsy for plasmacytoma. Now at age 73, she newly presented with the onset of a progressive paraparesis of 4 weeks' duration. On examination, she had 3/5 strength in both lower extremities accompanied by diffuse hyperreflexia, and bilateral Babinski signs. She underwent a D5-D7 decompression, D6 corpectomy with anterior mesh cage reconstruction, and a D3-D9 posterior fusion. CONCLUSION: Patients originally treated for plasmacytoma present 50% of the time with the new onset of neurological symptoms and signs due to the subsequent evolution of MM. As these lesions may be refractory to radiation and/or chemotherapy, surgery is often warranted.

Gene Xpert/MTB RIF assay for spinal tuberculosis- sensitivity, specificity and clinical utility.

BACKGROUND: Xpert MTB/RIF assay is a rapid automated molecular test with excellent reported sensitivity, specificity for diagnosis of pulmonary and extrapulmonary Mycobacterium tuberculosis (MTB) infections. However, the clinical utility and accuracy in STB is not well established. A study was conducted to report on the sensitivity, specificity and clinical utility of the Xpert MTB/RIF assay in spinal tuberculosis (STB). METHODS: A retrospective review of medical records was performed for 136 patients that underwent spinal biopsy for suspected spondylodiscitis. Reports for acid fast bacilli (AFB) smear, gram stain, pyogenic culture, MTB culture, histopathology, Xpert MTB/RIF assay, and drug sensitivity testing were reviewed. 'Reference standard for diagnosis of STB' was based on positive histopathology and/or MTB culture evidence and was considered as MTB positive. Any samples returning a positive pyogenic or fungal culture were considered as MTB negative. The sensitivity, specificity for Xpert MTB/RIF was assessed against the reference standard. RESULTS: A total of 125 patients were considered for final analysis, 86 patients met the criteria for 'Reference standard for diagnosis of TB spine' (MTB positive). This includes nine patients that were MGIT culture only positive; 45 that were histopathology only positive and 32 were both culture and histopathology positive. There were 39 culture proven (pyogenic-37 and fungal-2) patients included in MTB negative group. The 86 MTB positive patients, included 53 (61.6%) tissue samples and 33 (38.4%) pus samples. The overall analysis showed a 65.1% sensitivity, 100% specificity, 100% PPV and 56.5% NPV for the Xpert MTB/RIF. CONCLUSIONS: Gene Xpert MTB/RIF showed excellent specificity and was accurate in the identification of drug resistance. The sensitivity was 65% and sampling techniques using pus samples rather than tissue samples could be a possible reason for lower sensitivity.

A Polyostotic Paget's Disease Involving Lumbar Spine Presenting with Cauda Equina Syndrome: An Unusual Entity.

Introduction: Paget's disease of bone (PDB) is a metabolic bone disease presenting as polyostotic or monostotic lesions of the spine. Although common in the Anglo-Saxon population, it is rare on the Indian subcontinent. Neurological complications though infrequent can be severe in pagetic spine. Case Report: We report a case of a polyostotic variant of PDB involving lumbar spine (L2 vertebrae), iliac bones, and femur presenting as chronic low back pain and neurological deficit, i.e., cauda equina syndrome. On initial workup, a diagnosis of PDB was made and given cauda equina compression with neurological deficit, posterior spinal decompression, and biopsy was performed. The histopathological evaluation confirmed the diagnosis and the patient was treated with bisphosphonates for 6 months, along with serial monitoring of alkaline phosphatase levels. Conclusion: Through this case report, we hope to emphasize that PDB should be considered as a possible cause of neurological symptoms at presentation, especially in elderly patients. Also furthermore, early surgical intervention followed by bisphosphonates therapy can lead to favorable outcomes in such patients.

A Stepwise Posterolateral Approach for Computed Tomography Guided C2 (Axis) Transpedicular Biopsy: A Technical Note.

Introduction: Minimally invasive percutaneous CT-guided biopsies of the spine are well established. Although, technical difficulties with CT-guided percutaneous intervention of the C2 body present due to the smaller size of the vertebral elements and potential injury of the critical adjacent structures such as Carotid arteries laterally, vertebral artery, and cervical nerve posterolaterally, pharynx and larynx anteriorly, and spinal cord in the cervical spinal canal. Routinely transoral approach is used for the percutaneous intervention of the C2 body. Literature on the posterolateral approach for biopsies of the C2 vertebral body is sparse as compared to other approaches. This case report presents a case of adenocarcinoma diagnosed with CT-guided percutaneous biopsy of the C2 body using a posterolateral approach under local anesthesia. Case Report: A 70-year-old female presented to our outpatient clinic with complaints of progressively increasing neck pain with a visual analog score (VAS) 7/10. Neck pain was radiating to the base of the occiput and aggravated by neck movements. On clinical examination, there was axial tenderness at the base of the skull and the upper part of the cervical spine. Neurological examinations of sensory and power in all the limbs were normal. Systemic examination and laboratory parameters did not reveal any abnormality. X-rays and MRI revealed a fracture of the odontoid process with marrow edema with differentials of metastasis. PET scan revealed left lung lesion likely to be primary lesion and lesion in C2 vertebral body as likely metastasis. A minimally invasive percutaneous CT-guided posterolateral approach for biopsy proved moderately differentiated adenocarcinoma from the lung with metastasis to C2 vertebrae. The patient was started on an appropriate Chemotherapy regimen as per the Immunohistochemistry (IHC) and Genomic studies with adjuvant radiotherapy. Conclusion: Understanding the detailed anatomy prior to CT guided minimally invasive percutaneous C2 biopsy procedure helps in increasing its safety, precision, and high yield. Stepwise approach to the procedure aids in getting repeatable and high-yielding results especially in a technically challenging area such as C2 vertebrae.

Clinical and radiological factors associated with postoperative shoulder imbalance and correlation with patient-reported outcomes following scoliosis surgery.

BACKGROUND: Shoulder balance (SB) is an important cosmetic concern and is a determinant to assess outcomes following scoliosis surgery. Shoulder imbalance (SI) has been studied predominantly in idiopathic scoliosis with limited literature on other etiologies. PURPOSE: To assess SB following scoliosis surgery and correlate SRS-30 self-image scores with radiological shoulder imbalance SI. METHODS: A retrospective analysis was performed for 43 patients undergoing scoliosis surgery with a minimum 2-year follow-up. Radiological SI was assessed by the coracoid height difference on whole spine standing radiographs at preoperative, 12-weeks postoperative and 2-year follow-up. The preoperative Cobb angle, postoperative Cobb angle and mean correction were recorded. The upper and lower end vertebrae (UEV/LEV), and instrumented vertebrae (UIV/LIV) were documented. The aetiology of scoliosis and functional outcomes based on the SRS-30 questionnaire were noted. RESULTS: There were 19 males and 24 females with a mean age of 14.5 ± 4.7 years. The 12-week postoperative radiographs showed SI in 15 patients and residual SI in 7 patients at 2-year follow-up. SI was seen in four congenital scoliosis with segmentation or mixed anomalies in the proximal thoracic spine. Two idiopathic scoliosis (Lenke type 1 and type 3) showed SI where the UIV was T3 and T2 respectively. The mean preoperative SRS-30 score for patients with SB (N = 9) was 2.5 ± 0.72 and for SI (N = 34) was 3 ± 0.42 without significant difference (p > 0.5). The final mean SRS-30 self-image score for patients with SB was 3.7 ± 0.54 and for patients with SI was 3.7 ± 0.53 without significant difference (p > 0.05). CONCLUSION: Radiological SI assessed by coracoid height difference was not associated with a significant difference in SRS 30 scores preoperatively and at 2 year follow up. SI was seen with congenital scoliosis associated with segmentation and mixed anomalies of the proximal thoracic spine.