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.

Ultrasound-guided sub-multifidus block for postoperative pain after lumbar spine surgery - a prospective case series

We describe this series of 15 cases who were scheduled for single level lumbar spine decompression with instrumentation. Here we describe ultrasound (US) guided sub-multifidus block (SMFB). Injections of local anesthetic deep to the multifidus muscle provided reliable block of dorsal rami of spinal nerves at multiple levels in this series. With US the multifidus muscle can be identified both in axial and parasagittal planes. Needle tip is easily visualized beneath the multifidus and medial to transverse process. A good quality analgesia was documented by pain scores. There were no adverse events. This block needs to be compared with routine multimodal analgesia or with the recently describe thoracolumbar interfascial plane block to compare safety and analgesic efficacy.

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.

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.

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.

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.

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.

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.