The combination of intraoperative CT navigation and C-arm fluoroscopy for INFIX and percutaneous TITS screw placement in the treatment of pelvic ring injury: technical note

Background The subcutaneous screw rod system, commonly known as the internal pelvic fixator (INFIX), is useful in managing unstable pelvic ring fractures. Conventional INFIX and transiliac–transsacral (TITS) screw techniques are performed using C-arm fluoroscopy. There have been problems with medical exposure and screw insertion accuracy with these techniques. This work describes new INFIX and TITS techniques using intraoperative computed tomography (CT) navigation and C-arm fluoroscopy for pelvic ring fracture. Methods A typical case is presented in this study. An 86-year-old woman suffered from an unstable pelvic ring fracture due to a fall from a height. INFIX and TITS screw fixation with intraoperative CT navigation were selected to optimize surgical invasiveness and proper implant placement. Results The patient was placed in a supine position on a Jackson table. An intraoperative CT navigation was imaged, and screws were inserted under the navigation. Postoperative X-rays and CT confirmed that the screw was inserted correctly. This technique was less invasive to the patient and had little radiation exposure to the surgeon. Rehabilitation of walking practice was started early after the surgery, and she was able to walk with the assistance of a walker by the time of transfer. Conclusions The technique employed in our case study has the cumulative advantages of safety, accuracy, and reduced radiation exposure, together with the inherent advantages of functional outcomes of previously reported INFIX and TITS screw techniques. Further experience with this approach will refine this technique to overcome its limitations and facilitate its wider use.

Workflow and performance of intraoperative CT, cone-beam CT, and robotic cone-beam CT for spinal navigation in 503 consecutive patients

OBJECTIVE A direct comparison of intraoperative CT (iCT), cone-beam CT (CBCT), and robotic cone-beam CT (rCBCT) has been necessary to identify the ideal imaging solution for each individual user’s need. Herein, the authors sought to analyze workflow, handling, and performance of iCT, CBCT, and rCBCT imaging for navigated pedicle screw instrumentation across the entire spine performed within the same surgical environment by the same group of surgeons. METHODS Between 2014 and 2018, 503 consecutive patients received 2673 navigated pedicle screws using iCT (n = 1219), CBCT (n = 646), or rCBCT (n = 808) imaging during the first 24 months after the acquisition of each modality. Clinical and demographic data, workflow, handling, and screw assessment and accuracy were analyzed. RESULTS Intraoperative CT showed image quality and workflow advantages for cervicothoracic cases, obese patients, and long-segment instrumentation, whereas CBCT and rCBCT offered independent handling, around-the-clock availability, and the option of performing 2D fluoroscopy. All modalities permitted reliable intraoperative screw assessment. Navigated screw revision was possible with each modality and yielded final accuracy rates > 92% in all groups (iCT 96.2% vs CBCT 92.3%, p < 0.001) without a difference in the accuracy of cervical pedicle screw placement or the rate of secondary screw revision surgeries. CONCLUSIONS Continuous training and an individual setup of iCT, CBCT, and rCBCT has been shown to permit safe and precise navigated posterior instrumentation across the entire spine with reliable screw assessment and the option of immediate revision. The perceived higher image quality and larger scan area of iCT should be weighed against the around-the-clock availability of CBCT and rCBCT technology with the option of single-handed robotic image acquisition.

Bilateral open sacroiliac joint fusion during adult spinal deformity surgery using triangular titanium implants: technique description and presentation of 21 cases

OBJECTIVE Pelvic fixation enhances long constructs during deformity surgery. Subsequent loosening of iliac screws and pain at the pelvis occur in as many as 29% of patients. Concomitant sacroiliac (SI) fusion may prevent potential pain and failure. The objective of this study was to describe a novel surgical technique and a single institution’s experience using bilateral SI fusion during adult deformity surgery with S2-alar-iliac (S2AI) screws and triangular titanium rods (TTRs) placed with navigation. METHODS The authors reviewed open SI joint fusions with TTR performed between August 2019 and March 2020. All patients underwent lumbosacral fusion through a midline approach and bilateral S2AI pelvic fixation in the caudal teardrop, followed by TTR placement just proximal and cephalad to the S2AI screws using intraoperative CT imaging guidance. RESULTS Twenty-one patients were identified who received 42 TTRs, ranging in size from 7.0 × 65 mm to 7.0 × 90 mm. Three TTRs (7%) were malpositioned intraoperatively, and each was successfully repositioned during index surgery without negative sequelae. All breaches occurred in a medial and cephalad direction into the pelvis. Incremental operative time for adding TTR averaged 8 minutes and 33 seconds per implant. CONCLUSIONS Image-guided open SI joint fusion with TTR during lumbosacral fusion is technically feasible. The bony corridor for implant placement is narrower cephalad, and implants tend to deviate medially into the pelvis. Detection of malpositioned implant is aided with intraoperative CT, but this can be salvaged. A prospective randomized clinical trial is underway that will better inform the impact of this technique on patient outcomes.

Association Between Intraoperative Computed Tomography Navigation System and Incidence of Surgical Site Infection in Patients with Spinal Surgeries: A Retrospective Analysis

Purpose: Although the use of intraoperative computed tomography (CT)-based navigation systems is unlikely to cause intraoperative contamination more than the use of intraoperative fluoroscopy, the association between intraoperative CT/navigation and surgical site infections (SSIs) remains unclear. We investigated the incidence of SSIs and the association between intraoperative CT/navigation and SSIs for spinal surgeries.Methods: Of the 512 patients who underwent spinal surgery between April 2016 and December 2020, 304 underwent C-arm intraoperative fluoroscopy and/or Medtronic O-arm intraoperative CT/navigation system. We investigated the incidence of SSIs in patients with four techniques; no intraoperative imaging C-arm only, O-arm only, and both O- and C-arm used. Multivariate logistic analyses were conducted using the prevalence of SSIs as the dependent variable. The independent variables were age, sex, and potential confounders including preoperative Japanese Orthopaedic Association (JOA) score, use of instrumentation, C-arm and/or O-arm. Results: The incidence of the SSIs in patients with no imaging, C-arm only, O-arm only, and both modalities used was 1.9％, 7.3%, 4.7%, and 8.3%, respectively. There was no significant difference in the incidence of SSIs between the four techniques. Multivariate logistic analyses showed a significant correlation between the prevalence of SSI and JOA scores (odds ratio, 0.878; 95%CI, 0.759-0.990) and use of instrumentation (odds ratio, 6.241; 95%CI, 1.113-34.985), but not use of O-arm.Conclusions: The incidence of the SSIs in patients with only O-arm used was 4.7%. Preoperative clinical status and use of instrumentation, but not use of the O-arm, was associated with SSIs after spinal surgeries.

The Combination of Intraoperative CT Navigation and C-arm Fluoroscopy for INFIX and Percutaneous TITS Screw Placement in the Treatment of Pelvic Ring Injury: Technical Note

BACKGROUND: The subcutaneous screw rod system, commonly known as the internal pelvic fixator (INFIX), is useful in managing unstable pelvic ring fractures. Conventional INFIX and transiliac–transsacral (TITS) screw techniques are performed using C-arm fluoroscopy. There have been problems with medical exposure and screw insertion accuracy with these techniques. This work describes new INFIX and TITS techniques using intraoperative computed tomography (CT) navigation and C-arm fluoroscopy for pelvic ring fracture.METHODS: Here is a typical case. An 86-year-old woman suffered an unstable pelvic ring fracture due to a fall from a height. INFIX and TITS screw fixation with intraoperative CT navigation was selected to optimize surgical invasiveness and proper implant placement.RESULTS: The patient was placed in a supine position on a Jackson table. An intraoperative CT navigation was imaged, and screws were inserted under the navigation. Postoperative X-rays and CT confirmed that the screw was inserted correctly. This technique was less invasive to the patient and had little radiation exposure to the surgeon. Rehabilitation of walking practice was started early after the surgery, and she was able to walk with the assistance of a walker by the time of transfer. CONCLUSIONS: The technique employed in our case study has the cumulative advantages of safety, accuracy, and reduced radiation exposure, together with the inherent advantages of functional outcomes of previously reported INFIX and TITS screw techniques. Further experience with this approach will refine this technique to overcome its limitations and facilitate its wider use.

Stereotactic cryoablation of large tumors of the sellar region with intraoperative CT scans—technical note

Background Cryoablation has been used by neurosurgeons in the past and is currently being used by other disciplines to treat kidney cancer, skin lesions, and cardiac conduction defects. Because the currently available cryogenic probes can safely create large lesions and the lesion generation (in the form of ice-ball) can be monitored on intraoperative CT images, cryoablation was used to treat large tumors in and around the sella. In this paper, the author describes a technique to perform this procedure. Main body Three large tumors in 3 patients were treated with this method. Age of the patients was 26–58 years with a male/female ratio of 2/1. Patient 1 had a non-secreting pituitary adenoma (measuring 8 × 8 cm) and presented with long-standing total visual loss in both eyes, severe headache, and seizures. She had previous resection and radiation therapy. Patient 2 had prolactinomas (measuring 5.1 × 4.6 cm) and presented with progressive loss of vision and diplopia. Patient 3 had recurrent craniopharyngioma (measuring 7.2 × 5 cm) with prior treatment with resection radiation and frequent drainage of the cyst. He presented with headache and progressive worsening of his vision. The procedure was done on the CT table with intraoperative scans, using Patil stereotactic frame and argon cryoablation probe (Healthtronics). 3-D images were used to plan targets and trajectories. The probe was placed at the target via a trans-nasal trans-sphenoidal route. One to 3 lesions measuring 2.5–3 cm in diameter were made to ablate the tumor. Ice-ball formation was monitored live on CT images. There is no complication. One patient had near-complete resolution of the tumor, two had partial resolution of their tumors, and all had resolution of their presenting symptoms at follow-up of 3–24 months (median 6 months). In one patient, symptoms reoccurred due to the formation of new tumor masses. Short conclusion Cryoablation of intracranial tumors and can be done safely and effectively. Live monitoring of lesion generation using CT imaging is a major advantage of this technique.