Intraoperative O-arm Navigation Research Articles

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

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. 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. 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. 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.

Minimally Invasive C1-3 Posterior Spinal Fusion With Intraoperative O-arm Navigation: 2-Dimensional Operative Video.

Minimally Invasive C1-3 Posterior Spinal Fusion With Intraoperative O-arm Navigation: 2-Dimensional Operative Video.

Commentary: Minimally Invasive C1-3 Posterior Spinal Fusion With Intraoperative O-Arm Navigation: 2-Dimensional Operative.

Commentary: Minimally Invasive C1-3 Posterior Spinal Fusion With Intraoperative O-Arm Navigation: 2-Dimensional Operative.

Posterolateral Floating Technique for the Thoracic Ossification of the Posterior Longitudinal Ligament with Navigation: A Technical Note.

We describe a floating technique via a posterolateral approach with intraoperative O-arm navigation to facilitate decompression of the spinal cord in thoracic myelopathy due to severe ossification of the posterior longitudinal ligament (OPLL). A 62-year-old man with myelopathy due to thoracic OPLL had left-leg muscle weakness, urinary disturbance, and spastic gait. Bilateral leg pain and gait disturbance had persisted for 2 years. He was successfully treated by the posterolateral OPLL floating procedure and posterior pedicle fixation under O-arm navigation. At a 2-year follow-up, manual muscle testing results and sensory function of the left leg had recovered fully. His cervical Japanese Orthopedic Association score had improved from 5/12 to 11/12. The novel intraoperative O-arm navigation-guided posterolateral floating procedure for thoracic OPLL is effective for achieving precise decompression and strong fixation with a posterior approach only and can provide an excellent result for severe thoracic OPLL without the risk of adverse events from intraoperative radiation.

Risk Factors for the Drift Phenomenon in O-arm Navigation-Assisted Pedicle Screw Placement during Spinal Deformity Surgery.

Intraoperative O-arm navigation systems improve the accuracy of spinal instrumentation placement. However, deviation of the pedicle screw from the guide line might occur. The aim of the present study was to explore the causes of and countermeasures for the drift phenomenon during pedicle screw implantation with the aid of an O-arm three-dimensional navigation system in spinal deformity surgery. This was a retrospective analysis of 341 patients with spinal deformity who underwent O-arm navigation system-assisted pedicle screw placement from July 2015 to June 2019. The patient's general condition, Cobb angle, apical vertebra position, softness index, spinal release status, fixed reference frame position, and distance between the navigation vertebral body and the reference frame were collected and compared by independent-samples t test or Pearson's chi-square analysis. The potential risk factors for the drift phenomenon were identified using binary logistic regression analysis. The drift phenomenon occurred in 57 patients during the first navigation-assisted pedicle screw placement, for an incidence of 16.7% (57/341). There were significant differences in factors such as the apical vertebra position, softness index, spinal release status, and distance between the vertebral body and the reference frame when the drift phenomenon occurred (P < 0.05). Binary logistic regression analysis showed that the softness index, spinal release status, and distance between the vertebral body and the reference frame when drifting occurred were independent risk factors for the drift phenomenon during O-arm navigation-assisted pedicle screw placement. During the use of an O-arm navigation system to assist with pedicle screw placement, pedicle screws should not be placed away from the reference frame, and spinal osteotomy and release should be performed after pedicle screw placement. In addition, the accuracy of O-arm navigation-assisted pedicle screw placement will be affected more in those with larger softness indices.

Radiation Dose Reduction and Surgical Efficiency Improvement in Endoscopic Transforaminal Lumbar Interbody Fusion Assisted by Intraoperative O-arm Navigation: A Retrospective Observational Study.

ObjectiveEndoscopic transforaminal lumbar interbody fusion (Endo-TLIF) has gained increasing popularity among spine surgeons. However, with the use of fluoroscopy, intraoperative radiation exposure remains a major concern. Here, we aim to introduce Endo-TLIF assisted by O-arm-based navigation and compare the results between O-arm navigation and fluoroscopy groups. MethodsSixty-four patients were retrospectively analyzed from May 2019 to September 2020; the nonnavigation group comprised 34 patients, and the navigation group comprised 30 patients. Data on radiation dose, blood loss, postoperative drains, surgery time, complications, and length of hospital stay (LOS) were collected. Clinical outcomes were evaluated from postoperative data such as fusion rate, Oswestry Disability Index (ODI), and visual analogue scale (VAS). Radiation dose and surgery time were selected as primary outcomes; the others were second outcomes. ResultsAll patients were followed up for at least 12 months. No significant differences were detected in intraoperative hemorrhage, postoperative drains, hospital LOS, or complications between the 2 groups. The radiation dose was significantly lower in the navigation group compared with the nonnavigation group. The time of cannula placement and pedicle screw fixation was significantly reduced in the navigation group. No significant differences were detected between the clinical outcomes in the 2 groups (VAS and ODI scores). ConclusionThe present study demonstrates that O-arm-assisted Endo-TLIF is efficient and safe. Compared with fluoroscopy, O-arm navigation could reduce the radiation exposure and surgical time in Endo-TLIF surgery, with similar clinical outcomes. However, the higher doses exposed to patients remains a negative effect of this technology.

Intraoperative assisted O-arm navigation imaging for unstable pelvic fractures in INFIX

To investigate the effect of internal external fixator assisted O-arm navigation imaging in the treatment of unstable pelvic fractures. From May 2019 to November 2019, 15 patients with unstable pelvic fractures were treated by intraoperative O-arm navigation imaging using INFIX technology. There were 6 males and 9 females. The age ranged from 24 to 66 years old. The course of disease ranged from 2 to 14 days. According to Tile classification, there were 1 case of B1 type, 8 cases of B2 type, 3 cases of C1 type, and 3 cases of C2 type. According to Young-Burgess classification, there were 8 cases of LC, 1 case of APC, 4 cases of VS, 2 cases of CM. Preoperative routine pelvic anteroposterior film, entrance position, exit position and pelvic CT three-dimensional reconstruction were performed. Intraoperative O-arm navigation system three-dimensional reconstruction and triplane scanning imaging were used to evaluate the effect of intraoperative reduction. The anterior pelvic ring was fixed with internal external fixator, and the posterior ring was fixed with sacroiliac screw, plate screw or lumbar iliac screw. The operation time, intraoperative bleeding and nail placement were observed and recorded. The quality of fracture reduction was evaluated by Matta standard, and the postoperative function was evaluated by Majeed function score. Wound healing was good in all patients without vascular, nerve and local irritation complications. All the 15 patients were followed up for 10 to 16 months. The fracture reduction was evaluated according to the Matta scoring standard, 9 cases were excellent results, 5 cases were good, and 1 case was medium. The Majeed functional score was 0 to 95 points. The built-in external fixator assisted O-arm navigation imaging system in the treatment of unstable pelvic fractures. The reduction effect is evaluated in advance, the operation time is shortened, and the accuracy of internal fixation is improved. The operation is simple, safe and less bleeding. The operation is in line with the principles of minimally invasive medical treatment and precision medical treatment in orthopedics, which is conducive to the recovery of patients' postoperative function and rapid recovery.

Individual Navigation Templates for Subcortical Screw Placement in Lumbar Spine.

Subcortical screw placement is currently performed using frontal view fluoroscopy or intraoperative O-arm navigation system. The emergence of a novel technique for spinal navigation based on individual navigation templates created using 3D printing technology determines the need to study their safety and effectiveness in subcortical implantation.The aim of the study was to evaluate and compare the efficacy of subcortical implantation of pedicle screws in the lumbar spine using individual navigation templates versus intraoperative fluoroscopy.Materials and MethodsThe study was based on the analysis of treatment results in 39 patients who underwent surgery with subcortical implantation of 130 screws using the MidLIF technique. In group 1, navigation templates were used, in group 2 — intraoperative fluoroscopic control. Comparative analysis of implantation correctness and time, the total operation time, and radiation load was performed.ResultsThe mean distance between the screw and the cortical plate recorded in the groups ranged within 1.20–3.97 mm, without statistically significant difference (p>0.05). The mean time of pedicle screw implantation was 137.0 [115.25; 161.50] s in group 1 and 314.0 [183.50; 403.25] s in group 2. The total operation time was reduced from 173.0 [155.0; 192.25] min in group 2 to 119.0 [108.0; 128.75] min in group 1. The average of 1.0 [1.0; 2.0] X-ray image was performed to place one screw in group 1, while it was 12.0 [10.0; 13.25] in group 2. The differences between the groups in terms of implantation time and radiation load were statistically significant (p<0.05).ConclusionCompared with intraoperative fluoroscopy, the use of individual navigation templates for subcortical implantation of pedicle screws provides their correct positioning with a significant reduction in both operation time and radiation load at similar safety.

Intraoperative O-arm navigation guided anterior cervical surgery; A technical note and case series

BackgroundNavigation surgery is becoming very popular for anterior cervical surgery. However, one difficult problem for anterior cervical surgery is setting the reference frame (RF), due to the lack of reliable structures. If the RF is attached to the head holder or operation table instead of the patient, the accuracy of navigation is not good. Materials and methodsThis retrospective study included six patients who underwent anterior cervical surgeries with O-arm navigation. The RF was attached to the Caspar retractor using a special adaptor. Patients comprised three men and three women with a mean age of 62.8 years. Anterior cervical discectomy and fusion was performed in three cases, and anterior cervical corpectomy and fusion in three cases. We evaluated the accuracy of navigation, surgical time, intraoperative blood loss, complications, bony fusion, and clinical results. ResultsMean accuracy of anterior navigation was 1.1 ± 0.7 mm (range, 0–2 mm). Mean surgical time and blood loss were 166 ± 39 min (range, 121–359 min) and 280 ± 189 ml (range, 50–600 ml), respectively. Complications comprised one case of postoperative C5 palsy that recovered within 6 months. Mean Japanese Orthopedic Association (JOA) recovery rate was 52.4% (range, 20–100%). Adequate decompression and solid fusion were obtained in all cases. ConclusionsIntraoperative O-arm navigation-guided anterior cervical decompression and fusion is an effective technique for achieving precise decompression. This new navigation technique provides excellent results for severe cervical ossification of the posterior longitudinal ligament (OPLL) with minimum risk of adverse events from intraoperative radiation. We advocate the use of this novel technique in cases of cervical canal stenosis due to large disc osteophyte complex and OPLL, and also in cases of distorted cervical anatomy due to deformity, tumor, or revision surgery.

Comparison of pedicle screw placement using O-arm navigation and navigational templates in an animal model experiment

Objective. To perform a comparative analysis of experimental pedicle screw placement using custom-made 3D-printed navigational templates and using O-arm (cone-beam computerized tomograph, CBCT) and navigation station. Material and Methods. The experiment was performed on five fresh anatomical specimens of the lamb thoracic and lumbar spine. In Group 1, 44 screws were inserted using O-arm and Stealth Station S7 navigation system, and in Group 2, 72 screws were inserted using 3D-printed navigational templates. The main comparison criterion was the safety of implantation assessed based on a grade (0 to 3) of cortical bone perforation on postoperative CT. The extra comparing criteria were the time of implantation and summary radiation exposure required for screw placement. In Group 2, the accuracy of implantation was analyzed by assessing the deviation (mm) of the actual screw trajectory from the planned one at the point of entry into the vertebra and at the intersection of the screw axis with the anterior cortical layer of the vertebral body (end point), and by measuring the angles between the trajectories. The results were evaluated for normal distribution and subjected to statistical analysis for paired independent groups using the Kruskal-Wallis test and Chi-square in the Statistica 10 software. Results. Analysis of the safety revealed significant difference between the groups (p &lt; 0.0001). In Group 2 there were not any cases of cortical bone perforation, in Group 1 (O-arm) grade 0 was registered for 28 (64 %) screws, grade 1 for 7(16 %) screws, grade 2 for 4 (9 %) screws, and grade 3 for 5 (11 %) screws. The average time of one screw placement was 81.00 (64.50; 94.00) sec in Group 1 and 40.75 (33.50; 52.25) sec in Group 2, p &lt; 0.001. In Group 2, the mean deviation of the entry point was 0.50 (0.34; 0.87) mm, and of the end point – 1.10 (0.66; 1.93) mm. The mean angle between the planned and actual trajectories was 2.76 (0.80; 4.89) degrees in the axial plane and 2.62 (1.43; 4.35) degrees in the sagittal plane. The average design time for one template was 8.75 (8.00; 9.75) min, and 3D printing time – 60 (57; 69) min. The approximate material cost for one template printing was 45 rubles, for one anatomical specimen of lamb thoracic and lumbar spine – 390 rubles. The CT dose index (CTDI) for the O-arm was 8.99–9.01 mGy, and dose length product (DLP) for one model (3 scans) was 432 mGr ´ sm. In Group 2, there was no intraoperative X-ray control, the CTDI for preoperative CТ was 10.37–10.67 mGy, and DLP was 459–477 mGr ´ sm. Conclusion. The results of the experiment on a lamb spine biomodel showed that pedicle screw placement with 3D custom-made navigational templates is associated with better results of the safety and the speed of implantation as compared to that with intraoperative O-arm navigation. This justifies the 3D-printed template using in case of increased mobility of the spine during implantation, where the accuracy of CT navigation is significantly reduced. In clinical practice, these conditions correspond to transpedicular fixation of the cervical spine and screw fixation of the C1–C2 vertebrae.

Intraoperative O-arm navigation guided anterior cervical corpectomy and fusion with minimally invasive cervical pedicle screw fixation (MICEPS) for severe ossification of the cervical posterior longitudinal ligament (OPLL): A technical note

BackgroundAnterior cervical corpectomy and fusion (ACCF) with floating technique is one of the best surgical interventions for severe ossification of the posterior longitudinal ligament (OPLL). However, insufficient decompression and a thinned ossification mass often lead to poor clinical outcome. This report describes a novel floating technique with intraoperative O-arm navigation to facilitate surgical treatment of the OPLL, which has not previously been described as a therapeutic option. Case descriptionAn 82-year-old woman with myelopathy of the OPLL was referred to our hospital. Activities of daily living had been restricted by severe left arm pain, myelopathy hand, and gait disturbance for 3 years. ACCF was performed under the guidance of O-arm navigation and C-arm-free minimally invasive cervical pedicle screw fixation (MICEPS). The patient was successfully treated surgically and manual muscle test results and sensory function of the left arm had recovered fully by final follow-up at 1 year. Japanese Orthopedic Association score of the patient had improved from 10/17 to 16/17. ConclusionsIntraoperative O-arm navigation-guided ACCF with C-arm-free MICEPS is an effective technique for achieving precise decompression and strong, minimally invasive fixation. This new anterior navigation technique provides an excellent result for severe OPLL without the risk of adverse events from intraoperative radiation.

Surgical Technique and Accuracy of S2 Alar-Iliac Screw Insertion Using Intraoperative O-Arm Navigation: An Analysis of 120 Screws

To evaluate the surgical technique and accuracy of S2 alar-iliac (SAI) screw placement using intraoperative O-arm-based 3-dimensional navigation (O-arm). This study involved 60 patients who underwent SAI screw placement using the O-arm system between September 2013 and September 2019. These surgeries were performed by 5 different surgeons. For O-arm-based SAI screw insertion, a reference frame was attached to the spinous process of the lower lumbar spine (usually L4) so as not to interfere with SAI screw insertion and to facilitate simultaneous L5-S posterior interbody fusion with navigation. The navigated probe, iliac tap, and screwdriver were used for SAI screw insertion. Screw placement accuracy and screw length were assessed using postoperative computed tomography. Perioperative complications were also evaluated. Mean age at surgery was 68.1 (range, 30-83) years. In total, 120 screws were inserted. Rate of accurate screw placement was 98.3% (118/120 screws). The 2 misplaced screws breached the anterior cortex of the sacrum. Mean screw length was 85.6 (range, 70-90) mm. There were no significant neurovascular or visceral complications perioperatively. SAI screw placement can be safely performed using the intraoperative O-arm system and our surgical technique.

Comparison of Atlantoaxial Fusion with Transarticular Screws and C1 Lateral Mass–C2 Screws Using Intraoperative O-Arm Navigation

This study compared the surgical outcomes of atlantoaxial fusion with transarticular screws (TASs) and C1 lateral mass-C2 screws (screw-rod constructs [SRCs]) using the intraoperative O-arm navigation system (O-arm). Among a total of 28 patients who underwent atlantoaxial fixation, 13 underwent TAS fixation and 15 underwent SRC fixation using the O-arm. All patients underwent Brooks procedure with iliac bone graft in addition to screw fixation. TAS fixation was performed for cases without high-riding vertebral artery (hVA). In the SRC group, pars or lamina screws were inserted for the side with a C2 hVA. Operative time, intraoperative bleeding, perioperative complications, screw accuracy, and bone union were evaluated. There were statistically significant differences in mean operative time between the 2 procedures (166 minutes in the TAS group vs. 212 minutes in the SRC group, P < 0.05) and in mean blood loss (80 vs. 185 mL, respectively; P < 0.01). Two patients developed temporary postoperative occipital neuralgia probably related to C2 nerve root in the SRC group. No screws violated the cortex in either group. Complete bone union was observed in all cases. O-arm-assisted TAS fixation had less intraoperative blood loss, shorter operative time, and fewer screw insertion complications than O-arm-assisted SRC fixation. O-arm-assisted TAS fixation is preferable for atlantoaxial fusion in patients without hVA.

Clinical application of intraoperative O-arm navigation in reverse shoulder arthroplasty

BackgroundInaccurate fixation and positioning of the glenoid component using conventional techniques are problematic in reversed shoulder arthroplasty (RSA). Our objective was to investigate the accuracy of O-arm navigation of the glenoid component in RSA. MethodsThis retrospective case–control study comprised 2 groups of 25 patients who underwent reversed shoulder arthroplasty with or without intraoperative O-arm navigation. The intraoperative goal was to place the component neutrally in the glenoid in the axial plane and 10° inferiorly tilted in the scapular plane. Glenoid version angle and inclination were measured by computed tomography obtained preoperatively and a year postoperatively. Operative time, intraoperative bleeding, and the presence of postoperative complications were recorded. ResultsCompared with the ideal, the range of error for version was 7.3° (SD 3.6°) in the control group and 5.6° (SD 3.6°) in the navigated group (P = 0.278), and the range of error for inclination was 18.3° (SD 11.7°) in the control group and 4.9° (SD 3.8°) in the navigated group (P = 0.0004). The mean operative time was 164.6 (SD 21.2) min in the control group and 192.0 (SD 16.2) min in the navigated group (P = 0.001). The mean intraoperative bleeding was 201.0 (SD 37.0) mL in the control group and 185.3 (SD 35.6) mL in the navigated group (P = 0.300). There were no complications reported related to the intraoperative O-arm navigation. ConclusionO-arm navigation may be a useful tool for the placement with inferior tilt of the glenoid procedure in reversed shoulder arthroplasty.

Contemporaneous biopsy and laser interstitial thermal therapy for two treatment-refractory brain metastases

Recurrent treatment-refractory brain metastases can be treated with modern adjuvant therapies such as laser interstitial thermal therapy (LITT). Since previously radiated lesions may be indolent (treatment effect) or recurrent tumor, histological confirmation may be helpful. The authors present the utility of contemporaneous biopsy and LITT using intraoperative O-arm navigation in a patient who presented with multiple refractory metastases. The authors demonstrate the utility of O-arm navigation to confirm intraoperative biopsy and LITT placement. Concurrent stereotactic biopsy and LITT may be a safe and efficacious method for both the diagnosis and treatment of deep lesions that are unamenable to standard adjuvant treatment modalities. The video can be found here: https://youtu.be/SUY-qiahMyo .

Percutaneous posterior combined C2 translaminar and pedicle screws using Intraoperative O-arm Navigation in an atypical traumatic spondylolisthesis: Technical notes

Abstract Introduction Traumatic spondylolisthesis is the second most common C2 fractures, no Class I or Class II evidence exists regarding the management of traumatic spondylolisthesis of the axis. Case presentation A 74-year-old German male presented to our emergency room with complaints of severe neck pain and difficulty in neck movements following a domestic accident 3 days ago. CT-cervical spine showed a pedicle fracture in the right side without displacement or angulation and fracture of the lamina in the contralateral side. We considered the fracture as potentially stable. Conservative treatment was recommended. The patient refused the immobilization with the neck collar. The patient underwent a combination of PD und TL percutaneous screw, as navigated instrumented fusion of the craniocervical junction using O-arm Navigation. During surgical approach, the surgeons used realtime images and reference-guiding device to decide the trajectory of the screws, two small skin incisions are placed posteriorly paramedian, the first to stabilize the lamina, the second to pass the right pedicle of C2. Operation time was 45 min and blood loss about 50 ml. The patient was discharge in day 3 and return to normal daily activity. Conclusions Percutaneous translaminar and pedicle screws stabilization in complex hangman's fractures using Intraoperative O-arm Navigation is a treatment option, provides a rapid return to normal life activity among patients who refuse the external immobilization or present difficult to apply external immobilization.

Accuracy of spinal screw fixation using intraoperative O-arm navigation: Consecutive series of 118 screws

Background: Imaging-guided surgery provides intraoperative realtime navigation for spinal surgery to prevent neurovascular injury. However, the initial experience of O-arm three‑dimensional (3D) navigation is less clarified. The study aims to evaluate the accuracy of O-arm 3D navigation-assisted spinal implantation. Materials and Methods: Total 118 transpedicle/lateral mass screws in 17 consecutive patients performed through O-arm 3D computed tomography (CT) imaging navigation. Screws accuracy, Visual analogue scale (VAS), and operation time were assessed. O-arm 3D navigation included 96 pedicle screws and 22 lateral mass screws. Results: There accuracy rate of screw implantation was 96.6% (114/118) without breach (Grade 0), whereas 3.4% (4/118) breach between 2 and 4 mm (Grade 2). In the cervical spinal, 12 pedicle screws were placed in 4 patients; 16.7% (2/12) exhibited a Grade 2 breach in one patient, who developed a new neurological deficit and required revision. In the lumbosacral spine, 2.78% (2/72) exhibited a Grade 2 breach in 2 patients. The mean ± standard deviation VAS of the patients in postoperative and preoperative status was 1.47 ± 0.50 and 3.58 ± 1.00, respectively. The operation time was significantly longer in O-arm navigation than in C-arm guidance (426.5 ± 180.4 vs. 317.9 ± 133.6 min, P ＜ 0.05). Conclusion: O-arm 3D navigation achieves a relatively high accuracy of pedicle and lateral mass screws implantation. The accumulation of experience for O-arm 3D CT during initial learning curve is still warranted to promote the accuracy of screws position and shorten operation time.