Robotics and navigation in spine surgery: A narrative review.

Introduction: In recent decades, there has been a rising trend of spinal surgical interventional techniques, especially Minimally Invasive Spine Surgery (MIS), to improve the quality of life in an effective and safe manner. However, MIS techniques tend to be difficult to adapt and are associated with an increased risk of radiation exposure. This led to the development of 'computer-assisted surgery' in 1983, which integrated CT images into spinal procedures evolving into the present day robotic-assisted spine surgery. The authors aim to review the development of spine surgeries and provide an overview of the benefits offered. It includes all the comparative studies available to date. Methods: The manuscript has been prepared as per "SANRA-a scale for the quality assessment of narrative review articles". The authors searched Pubmed, Embase, and Scopus using the terms "(((((Robotics) OR (Navigation)) OR (computer assisted)) OR (3D navigation)) OR (Freehand)) OR (O-Arm)) AND (spine surgery)" and 68 articles were included for analysis excluding review articles, meta-analyses, or systematic literature. Results: The authors noted that 49 out of 68 studies showed increased precision of pedicle screw insertion, 10 out of 19 studies show decreased radiation exposure, 13 studies noted decreased operative time, 4 out of 8 studies showed reduced hospital stay and significant reduction in rates of infections, neurological deficits, the need for revision surgeries, and rates of radiological ASD, with computer-assisted techniques. Conclusion: Computer-assisted surgeries have better accuracy of pedicle screw insertion, decreased blood loss and operative time, reduced radiation exposure, improved functional outcomes, and lesser complications.

New Onset Sacroiliac Joint Pain After Transforaminal Interbody Fusion: What Are the Culprits?

STUDY DESIGN: A retrospective case-control study. OBJECTIVE: Only a few studies have studied the incidence of new-onset SI joint pain following lumbar spine fusion surgery. We aimed to explore the association between new-onset SI joint pain following Transforaminal Lumbar Interbody Fusion (TLIF) for degenerative spine disorders and changes in spinopelvic parameters. METHODS: A retrospective review of hospital records and imaging database of a tertiary care institute was done for patients who underwent TLIF from October 2018 to October 2019. The 354 patients who satisfied the eligibility criteria were divided into 2 groups(Group A, new-onset SI joint pain group, n = 34 and Group B, normal controls, n = 320). Symptomatic relief (>70% reduction in the VAS [Visual Analogue Scale] score) after 15 minutes of SI joint injection was considered diagnostic of SI joint pain. Clinical and radiological spinopelvic parameters were compared between the 2 groups. RESULTS: Patients with postoperative SI joint pain (Group A) had significantly less preoperative and postoperative lumbar lordosis (p < 0.001) compared to the other group. Most of the patients in Group A had a cephalad migration of the apex postoperatively (30/34 patients) whereas majority of patients in group B had either predominant caudal migration (44/320 patients) or no migration of the lumbar apex (272/320 patients). CONCLUSIONS: The preoperative and postoperative lumbar lordosis are significantly less and the postoperative pelvic tilt is significantly high in patients with new-onset SI joint pain compared to the control group. The cephalad migration of the lumbar apex is significantly associated with new-onset SI joint pain.

Radiological changes in sagittal parameters after C1-C2 arthrodesis and their clinical correlation: is there a difference between traumatic and non-traumatic causes?

BACKGROUND: Compensatory changes in cervical sagittal alignment after C1-C2 arthrodesis have been reported in a few studies. No studies have explored the differences in these compensatory changes between traumatic and non-traumatic pathologies. Conflicting reports exist on the correlation between cervical sagittal parameters and neck pain or function. METHODOLOGY: Medical records of 81 consecutive patients [Jan 2010-Dec 2018] who underwent Harms arthrodesis were retrospectively reviewed. 53 patients were included in the final analysis. Radiological parameters [C0-C1, C1-C2, C2-C7 angles and T1 slope] and clinical parameters [VAS (Visual analogue scale) and NDI (Neck disability index)] were compared between the two groups, Group A (traumatic) and Group B (non-traumatic). RESULTS: The 53 patients [Group A (n = 24,) and Group B (n = 29)] had a mean age of 49.98 ± 21.82 years (42 males, 11 females). Mean follow up duration was 48.9 months. Δ C1-C2 angle is significantly correlated with ΔC2-C7 angle (Group A, p = 0.004; Group B, p = 0.015) but not with ΔC0-C1 angle (Group A, p = 0.315; Group B, p = 0.938). Though significant improvement in the clinical parameters (VAS/NDI) has been noted in both groups, Group A showed a greater improvement in VAS scores [Group A, (p < 0.001); Group B, (p < 0.023)]. CONCLUSIONS: The sub-axial sagittal profile was strongly correlated with the ΔC1-C2 angle in both groups. Group B showed greater changes in sagittal parameters after Harms fixation and Group A showed greater improvement in long-term functional outcomes. The final functional outcomes were not related to the initial or final radiological sagittal profile in both groups.

Introduction of a Novel "Segmentation Line" to Analyze the Variations in Segmental Lordosis, Location of the Lumbar Apex, and Their Correlation with Spinopelvic Parameters in Asymptomatic Adults.

STUDY DESIGN: Cross-sectional study. PURPOSE: This study aimed to understand the sagittal spinopelvic parameters, segmental lumbar parameters, and lumbar apex location in asymptomatic adults and analyze their correlations with each other. OVERVIEW OF LITERATURE: Roussouly and his colleagues reported that pelvic incidence (PI) influences the lower arc of lumbar lordosis, whereas Pesenti and his colleagues reported that PI influences only the proximal part of lordosis and not the distal part. Both studies have their shortcomings. METHODS: One hundred asymptomatic adult volunteers (mean age, 29.1±7.9 years; 69 males, 31 females) who satisfied the selection criteria were enrolled in this study. Standing antero-posterior and lateral whole spine and pelvis X-rays were performed, and the radiographic parameters were analyzed. We introduced a "segmentation line" bisecting the apical vertebra/disk to divide the upper arc of lumbar lordosis (ULL) and lower arc of lumbar lordosis (LLL). RESULTS: The mean PI was 48.02°, ULL 29.12°, LLL 16.02°, total lumbar lordosis (TLL) 45.14°, lumbar tilt angle 4.73°, and location of the apex of lumbar lordosis (LLA) 4.11°. The location of the lumbar apex moved higher as the PI increased. The PI was strongly positively correlated with the LLL (r =0.582, p <0.001) and TLL (r =0.579, p <0.001) but not with the ULL (r =0.196, p =0.05). The LLA was strongly positively correlated with the ULL (r =0.349, p <0.001), negatively with the LLL (r =-0.63, p <0.001), and not correlated with the TLL (r =-0.177, p =0.078). CONCLUSIONS: The PI influences the location of the lumbar apex, the LLL, and the TLL but not the ULL. The location of the lumbar apex significantly influences the segmental lordosis but not the TLL.

Extraosseous Spread of Multiple Myeloma Mimicking Pancoast Tumor.

A 55-year-old man presented with upper backache for one month, inability to move both the lower limbs for two weeks and retention of urine for five days. Examination revealed spastic paraplegia and reduced breath sounds in the right upper zone. Initial imaging revealed a soft tissue lesion in the apex of the right lung, suggesting a Pancoast tumor. It also showed a lytic, expansile lesion of the T2 vertebra extending to the right second posterior rib on subsequent imaging. High serum calcium, M-spike in beta-gamma globulin region on serum electrophoresis, 50%-60% plasmacytoid cells on bone marrow aspiration, concertina collapse of the vertebral body, and pattern of neurological deficit pointed towards multiple myeloma. T2 corpectomy and mesh cage placement, C7-T4 posterior stabilization, and resection of the second rib were done. Histopathology confirmed multiple myeloma. Postoperatively, the patient was managed with radiotherapy and bortezomib. The patient had a good neurological recovery. Timely intervention is critical for disease control and leads to better recovery.

Incidence and Risk Factors for Neurological Deterioration in Posterior Corrective Surgeries for Severe Angular Kyphotic Deformities: A 10-Year Institutional Retrospective Study.

STUDY DESIGN: Retrospective case-control study. OBJECTIVE: Neurological deficit is one of the dreaded complications of kyphotic deformity correction procedures. There is inconsistency in the reports of neurological outcomes following such procedures and only a few studies have analyzed the risk factors for neurological deficits. We aimed to analyze the factors associated with neurological deterioration in severe kyphotic deformity correction surgeries. METHODS: We performed a retrospective study of 121 consecutive surgically treated severe kyphotic deformity cases (49 males, 56 females) at a single institute (May 1st 2008 to May 31st 2018) and analyzed the risk factors for neurological deterioration. The demographic, surgical and clinical details of the patients were obtained by reviewing the medical records. RESULTS: 105 included patients were divided into 2 groups: Group A (without neurological deficit) with 92 patients (42 males, 50 females) and Group B (with neurological deficit) with 13 patients (7 males, 6 females) (12.4%). Statistically significant difference between the 2 groups was observed in the preoperative sagittal Cobbs angle (p < 0.0001), operative time (p = 0.003) and the presence of myelopathic signs on neurological examination (p = 0.048) and location of the apex of deformity (p = 0.010) but not in other factors. CONCLUSIONS: Preoperative Sagittal Cobbs angle, presence of signs of myelopathy, operative time and location of apex in the distal thoracic region were significantly higher in patients with neurological deterioration as compared to those without neurological deterioration during kyphotic deformity correction surgery. Distal thoracic curve was found to have 4 times more risk of neurological deterioration compared to others.

Surgical Outcomes of Transpedicular Decompression with or without Global Reconstruction in Thoracic/Thoracolumbar Pott's Spine: A 7-Year Institutional Retrospective Study.

STUDY DESIGN: Retrospective case-control study. PURPOSE: This study aimed to analyze the radiological and clinical outcomes of transpedicular decompression in spinal tuberculosis (or Pott's spine) with and without anterior reconstruction using polyetheretherketone (PEEK) or mesh cage. OVERVIEW OF LITERATURE: The outcomes of transpedicular decompression with and without global reconstruction in Pott's spine are insufficiently investigated. Additionally, the use of PEEK cages in Pott's spine has remained unestablished. METHODS: Using the hospital records and imaging database obtained from January 2014 to January 2020, this study retrospectively analyzed patients who underwent surgery for Pott's spine and met the eligibility criteria. RESULTS: This study included 230 patients with a mean±standard deviation age of 47.7±18.1 years (109 males, 121 females). The Visual Analog Scale score, Oswestry Disability Index, and Cobb angle were significantly improved in these patients (p<0.001). Patients who underwent anterior reconstruction had a greater correction in Cobb angle postoperatively (p=0.042) but also had a greater blood loss (p=0.04). During the follow-up, they experienced a significant loss of correction compared with those who only underwent transpedicular decompression (p=0.026). Nevertheless, patients who underwent anterior reconstruction using mesh/PEEK cages showed no significance difference in the clinical or radiological outcomes. CONCLUSIONS: Transpedicular decompression used in the surgical management of Pott's spine showed favorable clinical and radiological outcomes. The additional use of anterior reconstruction obtained equivalent clinical outcomes but resulted in excessive blood loss. Meanwhile, the use of mesh/PEEK cage for anterior reconstruction did not affect the clinical and radiological outcomes.

Intradural Conus Medullaris Lipoma With Neurological Deficit: A Rare Occurrence.

Intradural lipoma without spinal dysraphism is a rare occurrence. Most of them are asymptomatic but can also present with neurological deficits. A 54-year-old male patient presented to us with progressive weakness in both lower limbs for six months. On physical examination and radiological workup, intradural lipoma was diagnosed. Due to progressive neurological deficit, the patient was treated surgically. On 2.5 years of follow-up, the patient showed complete neurological recovery. Intradural lipomas can also present with the neurological deficit at any age and should be managed surgically if the deficit is progressive in nature. Surgical management has a good outcome if done within two years of onset of symptoms.

An extremely rare presentation of AV fistula: Massive destruction of multiple vertebral bodies with paraparesis.

BACKGROUND: Spinal ventral epidural arteriovenous fistulas (EDAVFs) are rare and underdiagnosed entities and usually present with benign symptoms such as radiculopathy. To the best of our knowledge, EDAVFs presenting with massive vertebral body destruction have not been reported in the literature. CASE DESCRIPTION: A young male presented with mid back pain for 1 year and weakness of both lower limbs for 3 months. He was clinicoradiologically diagnosed with spinal tuberculosis and started on antitubercular treatment elsewhere. Radiological investigations suggested destruction and collapse of T12 and L1 vertebrae. Prominent flow voids were seen in T9-L2 epidural space, likely prominent epidural vessels. The primary differential diagnoses were spinal tuberculosis and neoplastic etiologies. T9 to L3 surgical stabilization and anterior decompression by pediculectomy of left T12 and L was done. The surgeon encountered massive bleeding at the time of anterior decompression and a vascular etiology was suspected. Biopsy revealed negative results for infection or malignancy. DSA revealed ventral EDAVFs, and hence, transcatheter embolization was performed. He had excellent outcome on assessment at 21 months postoperative follow-up. CONCLUSION: Spinal epidural AVFs can rarely present with gross vertebral body destruction and paraparesis. Preoperative radiological assessment with suspicion of spinal epidural AVFs can help to avoid intraoperative difficulties and complications. Timely, management of spinal epidural AVFs can result in excellent outcomes.

"White Cord Syndrome" of Acute Tetraplegia after Posterior Cervical Decompression and Resulting Hypoxic Brain Injury.

White cord syndrome (WCS) is a rare case of severe neurological deterioration after surgical decompression for cervical myelopathy. It was proposed to be secondary to an ischemia/reperfusion injury. An association of WCS with a hypoxic brain injury (HBI) has not been documented. A 63-year-old man presented to us with progressive symptoms of cervical myelopathy. Computed tomography scan and magnetic resonance imaging (MRI) scan findings were suggestive of an ossified posterior longitudinal ligament with cord atrophy and myelomalacia changes. He was managed surgically by decompression and fusion through a posterior approach. During the surgery, there was a sudden loss of neuromonitoring signals after laminectomy, and wake-up assessment revealed neurological deterioration. Immediate postoperative imaging revealed adequately placed screws and adequate cord decompression. A high dose of intravenous steroids was given. Repeat MRI scan on the 3rd postoperative day suggested cord edema over a large area on T2-weighted images. He was diagnosed as WCS and managed conservatively. He had persistent abdominal distension postoperatively, and a diagnostic endoscopy was advised. At the start of the procedure, the patient had a sudden-onset loss of consciousness. Electrocardiogram suggested bradyarrhythmias with hypotension. The patient was resuscitated, intubated, and shifted to intensive care unit. He was diagnosed to have a HBI. He was managed with multidisciplinary rehabilitation and discharged at 4 months' postoperatively with stable vitals. There was no improvement in the neurology or his consciousness. Spine surgeons have to be aware of this potentially disastrous complication of WCS. One should take adequate postoperative care to avoid preventable complications like HBI associated with it.

Ligamentum Flavum Cyst With Acute Onset Motor Deficit: A Literature Review and Case Series.

BACKGROUND: Ligamentum flavum cysts have been rarely described in the literature and are one of the rare causes of neural compression and canal stenosis. Very few cases of their association with neurologic deficits are reported to date, and association with acute onset weakness is even rarer. CLINICAL PRESENTATION: We report our experience with 3 cases of ligamentum flavum cyst that presented with acute onset weakness and also present a comprehensive literature review on lumbar ligamentum flavum cysts reported to date. All 3 patients had symptoms of severe neurogenic claudication and presented to us with acute onset of motor weakness in lower limbs. Ligamentum flavum cyst was located in the midline in 2 cases and laterally in 1 case. We performed excision of the cyst and decompression with fusion in 2 cases and decompression alone in 1 case. All 3 cases had significant improvement in their neurologic status postoperatively. Histopathological examination confirmed ligamentum flavum cyst in all 3 cases. We performed a PUBMED and EMBASE database search using the MeSH (Medical Subject Headings) terms "ligamentum flavum" and "cysts" for articles published to April 2019. We could identify 7 studies describing 20 cases of lumbar ligamentum flavum cysts with motor weakness in the literature. Only 1 case had been described with an acute onset of weakness. CONCLUSIONS: Ligamentum flavum cysts should remain in the differential diagnosis of a patient who has symptoms of lumbar canal stenosis and presents with acute onset of neurological deficits. Such patients have a good improvement with surgery.

Advancements in osteoporotic spine fixation.

With the global rise in the population of elderly along with other risk factors, spine surgeons have to encounter osteoporotic spine more often. Osteoporotic spine, however, causes problems in management, particularly where instrumentation is involved, resulting in screw loosening, pull out, pseudoarthroses or adjacent segment kyphosis. Osteoporosis alters the bio mechanics at the bone implant interface resulting in various degrees of fixation failure. Various advancements have been made in this field to deal with such issues in addition to modification of basic surgical techniques such as increasing the diameter and length of the screw, smaller pilot hole, under tapping, longer constructs, supplemental anterior fixation, sublaminar wires or laminar hooks, use of transverse connectors and triangulation techniques, among others. They include novel surgical techniques such as cortical bone trajectory, superior cortical trajectory, double screw technique, cross trajectory technique, bicortical screw technique or prophylactic vertebroplasty. Advances in the screw design include expandable screws, fenestrated screws, conical screws and coated screws. In addition to PMMA cement augmentation, other biodegradable cements have been introduced to mitigate the side effects of PMMA such as calcium phosphate, calcium apatite and hydroxyapatite. Pharmacotherapy with teriparatide can aid fusion and lower the rate of pedicle screw loosening. Many of these strategies have only bio mechanical evidence and require well designed clinical trials to establish their clinical efficacy. Though no single technique is fool proof, little modifications in the existing techniques or utilizing a combination of techniques without adding to the cost of the surgery may help to achieve a near-ideal result. Surgeons have to equip their armamentarium with all the recent advances, and should be open to novel thoughts and techniques.

Robotic spine surgery: a review of the present status.

With technological advancements being introduced and dominating many fields, spine surgery is no exception. In view of the patient safety and surgeon's comfort, robotics has been introduced in spine surgery. Due to small corridors for work, little room for inaccuracy, lengthy and tedious procedures, spine surgery is an ideal scenario for robotics to establish as the standard of care. Spine robotics received their first FDA clearance in 2004. New generation of spine robotics with integrated navigation systems has become available now. The primary role of spine robotics, at present, is to aid pedicle screw fixation. High quality studies have been performed to establish its role in increasing the accuracy of pedicle fixation. Studies have also reported decreased radiation and decreased operative time with spine robotics. However, few studies have reported otherwise. It is still in its nascent stage in both industrial view and surgeon familiarity. Continued research to overcome the challenges such as high cost and steep learning curve is crucial for its widespread use. Also, expanding the scope of spine robotics beyond pedicle screw fixation such as osteotomies and dural procedures would be an area for potential research. This review is intended to provide an overview of various studies in the field of robotic spine surgery and its present status.

Clinicoradiological outcomes of Goel and Harms fixation for atlantoaxial instability: An institutional experience.

BACKGROUND: Few studies have reported on the long-term outcomes of Goel and Harms C1-C2 fusions in the Asian population. METHODS: This was a retrospective analysis of 53 patients undergoing Goel and Harms fixation (2010 -2018). Clinical outcomes were assessed utilizing the neck disability index (NDI), Japanese Orthopedic Association (JOA) score, and visual analog scale (VAS). Outcomes were then correlated with fusion rates (using dynamic X-rays), atlanto-dens interval (ADI), and space available for cord (SAC) data. RESULTS: The study's 53 patients averaged 49.98 years of age and included 42 males and 11 females. The mean preoperative versus postoperative scores on multiple outcome measures showed NDI 31.62 ± 11.05 versus decreased to 8.68 ± 3.76 post, mean JOA score (e.g., in 41 patients with myelopathy) improved from 13.20 ± 3.96 to 15.2 ± 2.17, and the mean VAS decreased from 4.85 ± 1.03 to 1.02 ± 0.87 and showed restoration of the ADI (1.96 ± 0.35 mm) and SAC (20.42 ± 0.35 mm). A 98.13% rate of C1-C2 fusion was achieved at 12 postoperative months. CONCLUSION: Goel and Harms technique for C1-C2 fusion resulted in both good clinical and radiological outcomes.

Magnetic resonance imaging findings in intervertebral disc herniation: Comparison of canal compromise and canal size in patients with and without cauda equina syndrome.

BACKGROUND: Surgical decompressions are typically warranted in patients with magnetic resonance (MR) and clinical evidence of cauda equina syndromes (CESs). However, it is still unclear what MR findings best correlate with such CES. Here, we compared MR-documented canal size and level/extent of compromise in 52 patients with and 56 others without CES attributed to lumbar disc herniation. METHODS: This was a retrospective study of 52 patients with and 56 patients without CES attributed to MR- documented lumbar disc herniations (IDHs). The anteroposterior diameters of the spinal canal and the levels of maximal compression were documented and compared utilizing MR scans from both groups. RESULTS: The 52 patients with CES had more extensive narrowing of the canal diameters at the L4-L5 and L5- S1 levels and higher mean canal compression ratios versus 56 patients without CES. The mean percentage of compression in the CES group at L4-L5 and L5-S1 levels (70% and 67.5%, respectively) was less versus L2-L3 and L3-L4 levels (89.7% and 81.8%, respectively). CONCLUSION: The 52 patients with CES due to IDH had greater canal compromise versus 56 without CES. Further, the percentage of canal compromise was less at L4-L5 and L5-S1 levels compared to other levels in patients with CES.

COVID-19: Current Knowledge and Best Practices for Orthopaedic Surgeons.

BACKGROUND: A mysterious cluster outbreak of pneumonia in Wuhan, China in December 2019 was traced to Severe Acute Respiratory Syndrome Coronavirus 2 and declared a Pandemic by WHO on 11th March 2020. The pandemic has spread rapidly causing widespread devastation globally. PURPOSE: This review provides a brief understanding of pathophysiology, clinical features, diagnosis and management of COVID-19 and highlights the current knowledge as well as best practices for orthopaedic surgeons. These are likely to change as knowledge and evidence is gained. RESULTS: Orthopaedic surgeons, like other front-line workers, carry the risk of getting infected during their practice, which as such is already substantially affected. Implementation of infection prevention and control as well as other safety measures for health care workers assumes great importance. All patients/visitors and staff visiting the hospital should be screened. Conservative treatment should be the first line of treatment except for those requiring urgent/emergent care. During lockdown all elective surgeries are to be withheld. All attempts should be made to reduce hospital visits and telemedicine is to be encouraged. Inpatient management of COVID-19 patients requires approval from concerned authorities. All patients being admitted to the hospital in and around containment zones should be tested for COVID-19. There are special considerations for anaesthesia with preference for regional anaesthesia. A separate Operation room with specific workflow should be dedicated for COVID-19 positive cases. CONCLUSIONS: Despite the magnitude of challenge, the pandemic offers significant lessons for the orthopaedic surgeon who should seek the opportunity within the adversity and use this time wisely to achieve his/her Ikigai.