Intraoperative 3D Computed Tomography: Spine Surgery

Top 25 Most Cited Articles on Intraoperative Computer Tomography-Guided Navigation in Spine Surgery

BACKGROUND

In recent years, the use of intraoperative computer tomography-guided (CT-guided) navigation has gained significant popularity among health care providers who perform minimally invasive spine surgery. This review aims to identify and analyze trends in the literature related to the widespread adoption of CT-guided navigation in spine surgery, emphasizing the shift from conventional fluoroscopy-based techniques to CT-guided navigation.

METHODS

Articles pertaining to this study were identified via a database review and were hierarchically organized based on the number of citations. An "advanced document search" was performed on September 28th, 2022, utilizing Boolean search operator terms. The 25 most referenced articles were combined into a primary list after sorting results in descending order based on the total number of citations.

RESULTS

The "Top 25" list for intraoperative CT-guided navigation in spine surgery cumulatively received a total of 2742 citations, with an average of 12 new citations annually. The number of citations ranged from 246 for the most cited article to 60 for the 25th most cited article. The most cited article was a paper by Siewerdsen et al., with 246 total citations, averaging 15 new citations per year.

CONCLUSIONS

Intraoperative CT-guided navigation is 1 of many technological advances that is used to increase surgical accuracy, and it has become an increasingly popular alternative to conventional fluoroscopy-based techniques. Given the increasing adoption of intraoperative CT-guided navigation in spine surgery, this review provides impactful evidence for its utility in spine surgery.

Multidimensional Fluoroscopy to Assess Closed Reduction in Displaced Young Femoral Neck Fractures: A Report of 3 Cases

CASE

The authors present 3 physiologically young patients with displaced femoral neck fractures who underwent initial closed reduction and provisional fixation. Multidimensional fluoroscopy was used to assess fracture reduction before definitive fixation, with 1 patient requiring an open approach because of inadequate fracture reduction after closed attempts.

CONCLUSION

Displaced femoral neck fractures in young patients remain difficult injuries to treat. Reduction quality is a significant predictor of patient outcomes. Intraoperative multidimensional fluoroscopy provides treating surgeons with a tool to assess fracture reduction after closed reduction maneuvers and allows for intraoperative treatment adjustment as needed.

Use of 3D Fluoroscopy to Assist in the Reduction and Fixation of Pelvic and Acetabular Fractures: A Safety and Quality Case Series

SUMMARY

Multidimensional fluoroscopy has been increasingly used in orthopaedic trauma to improve the intraoperative assessment of articular reductions and implant placement. Owing to the complex osteology of the pelvis, cross-sectional imaging is imperative for accurate evaluation of pelvic ring and acetabular injuries both preoperatively and intraoperatively. The continued development of fluoroscopic technology over the past decade has resulted in improved ease of intraoperative multidimensional fluoroscopy use in pelvic and acetabular surgery. This has provided orthopaedic trauma surgeons with a valuable tool to better evaluate reduction and fixation at different stages during operative treatment of these injuries. Specifically, intraoperative 3D fluoroscopy during treatment of acetabulum and pelvis injuries assists with guiding intraoperative decisions, assessing reductions, ensuring implant safety, and confirming appropriate fixation. We outline the useful aspects of this technology during pelvic and acetabular surgery and report its utility with a consecutive case series at a single institution. The added benefits of this technology have improved the ability to effectively manage patients with pelvis and acetabulum injuries.

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.

Navigated, percutaneous, three-step technique for lumbar and sacral screw placement: a novel, minimally invasive, and maximally safe strategy

BACKGROUND

Minimally invasive spine surgery is a field of active and intense research. Image-guided percutaneous pedicle screw (PPS) placement is a valid alternative to the standard free-hand technique, thanks to technological advancements that provide potential improvement in accuracy and safety. Herein, we describe the clinical results of a surgical technique exploiting integration of neuronavigation and intraoperative neurophysiological monitoring (IONM) for minimally invasive PPS.

MATERIALS AND METHODS

An intraoperative-computed tomography (CT)-based neuronavigation system was combined with IONM in a three-step technique for PPS. Clinical and radiological data were collected to evaluate the safety and efficacy of the procedure. The accuracy of PPS placement was classified according to the Gertzbein-Robbins scale.

RESULTS

A total of 230 screws were placed in 49 patients. Only two screws were misplaced (0.8%); nevertheless, no clinical sign of radiculopathy was experienced by these patients. The majority of the screws (221, 96.1%) were classified as grade A according to Gertzbein-Robbins scale, seven screws were classified as grade B, one screw was classified as grade D, and one last screw was classified as grade E.

CONCLUSIONS

The proposed three-step, navigated, percutaneous procedure offers a safe and accurate alternative to traditional techniques for lumbar and sacral pedicle screw placement. Level of Evidence Level 3. Trial registration Not applicable.

A New Noninvasive Frameless Registration System for Stereotactic Cranial Biopsy: A Technical Note

BACKGROUND

Although frame-based stereotactic biopsy is still considered the gold standard for brain biopsies, frameless robot-assisted stereotactic systems are now able to provide an equal level of safety and accuracy. However, both systems suffer from a lack of efficiency of the operative workflow.

OBJECTIVE

To describe the technique of a new frameless and noninvasive registration tool Neurolocate (Renishaw). This tool, combined with an intraoperative cone-beam computed tomography imaging system like O-ARM (Medtronic), might facilitate the achievement and workflow of robot-assisted stereotactic intracranial biopsies.

METHODS

Neurolocate is a 3-dimensional fiducial tool fixed directly on the Neuromate (Renishaw) robot arm. It consists of 5 radio-opaque spherical fiducials, whose geometry is constant. This tool made it possible to carry out the coregistration then the biopsy in the same operating time, following a five-step procedure described here. We retrospectively extracted selected preliminary results from our initial experience.

RESULTS

Over 1 year, 23 consecutive adult patients were biopsied with Neurolocate in our center. The mean overall operative time, from patient's installation to skin closure, was 97 minutes ± 27 (SD). The entire procedure took place in a single location unit (operating room), which facilitated workflow and surgical planning. No invasive gesture was performed outside of the operating time.

CONCLUSION

Neurolocate is a new frameless and noninvasive registration tool that could improve workflow and flexibility for operating room management and surgical planning. It may also increase the comfort of patients undergoing robot-assisted intracranial stereotactic biopsies. The accuracy and safety profile should be addressed in specific studies.

Clinical applications and prospects of 3D printing guide templates in orthopaedics

Background

With increasing requirements for medical effects, and huge differences among individuals, traditional surgical instruments are difficult to meet the patients' growing medical demands. 3D printing is increasingly mature, which connects to medical services critically as well. The patient specific surgical guide plate provides the condition for precision medicine in orthopaedics.

Methods

In this paper, a systematic review of the orthopedic guide template is presented, where the history of 3D-printing-guided technology, the process of guides, and basic clinical applications of orthopedic guide templates are described. Finally, the limitations of the template and possible future directions are discussed.

Results

The technology of 3D printing surgical templates is increasingly mature, standard, and intelligent. With the help of guide templates, the surgeon can easily determine the direction and depth of the screw path, and choose the angle and range of osteotomy, increasing the precision, safety, and reliability of the procedure in various types of surgeries. It simplifies the difficult surgical steps and accelerates the growth of young and mid-career physicians. But some problems such as cost, materials, and equipment limit its development.

Conclusions

In different fields of orthopedics, the use of guide templates can significantly improve surgical accuracy, shorten the surgical time, and reduce intraoperative bleeding and radiation. With the development of 3D printing, the guide template will be standardized and simplified from design to production and use. 3D printing guides will be further sublimated in the application of orthopedics and better serve the patients.

The translational potential of this paper

Precision, intelligence, and individuation are the future development direction of orthopedics. It is more and more popular as the price of printers falls and materials are developed. In addition, the technology of meta-universe, digital twin, and artificial intelligence have made revolutionary effects on template guides. We aim to summarize recent developments and applications of 3D printing guide templates for engineers and surgeons to develop more accurate and efficient templates.

Feasibility of 3.5mm C2 pedicle screws in children: Part II, a computerized tomography analysis

BACKGROUND

There have been no studies with large sample sizes on growth of the pedicle of C2 in children. In the present study we measured the pedicle of C2 through computed tomography (CT) imaging in children aged less than 14 years and evaluated the suitability of the 3.5-mm screw for the pedicle in such children.

METHODS

The study was conducted on CT morphometric images of 420 children in our hospital between June 2018 and June 2020. The width (D1), length (D2), height (D3), inclination angle (α), and tail angle (β) of the C2 pedicle were measured. One-way analysis of variance and Student's t test were used for statistical analyses. The least-square method was used to analyze the curve fitting the trend of anatomical change in the pedicle. The largest degree of goodness of fit determined the best-fitting curve.

RESULTS

The size of the pedicle of C2 increased with age. The median ranges of D1, D2, D3, α, and β were 3.312-5.431 mm, 11.732-23.645 mm, 3.597-8.038 mm, 32.583°-36.640°, and 24.867°-31.567°, respectively. The curves fitting the trends of D1 and D3 were power functions, whereas D2 was fitted by a logarithmic curve. However, no curve fitted α or β.

CONCLUSION

A 3.5-mm screw can be placed in the pedicle of C2 in children aged more than one year. The growth and development trend of this pedicle can provide an anatomical reference for deciding on posterior cervical surgery and for selecting and designing pedicle screws for children.

Dimensional accuracy of 3D printing navigation templates of chemical-based sterilisation

3D printed navigational templates have facilitated the accurate treatment of orthopaedic patients. However, during practical operation, it is found that the location hole occasionally deviates from the ideal channel. As such, there will be a security risk in clinical applications. The purpose of this study was to evaluate the influence of chemical-based sterilisation methods on the dimensional accuracy of different materials and the influence of module parameters on the degree of deformation. We found that polylactic (PLA) modules sterilised with ethylene oxide (EO) would undergo micro-deformation, and these micro-deformation characteristics depend on the building direction, i.e., the module stretches in the Z direction and shrinks in the X and Y directions. Heat-resisting polylactide (HR-PLA) has the same melting temperature (T_m) as PLA, but its glass transition temperature (T_g) is greater than the EO sterilisation temperature, so there is no obvious deformation after EO sterilisation. The layer height of the module were inversely proportional to the degree of deformation in the same sterilisation method. The deformation time of the module is concentrated within 2 h after heating. The micro-deformation of the 3D printing module depends on its T_g, sterilisation temperature, and duration of the sterilisation cycle.

Preoperative planning for intraoperative navigation guidance

Intraoperative navigation for spinal procedures has continued to gain popularity. Numerous platforms are currently on the market and offer a spectrum of features. Preoperative considerations when utilizing this technology begin with understanding the fundamental concepts and methods of navigation. Several key factors including patient positioning, reference array placement, and sequence of instrumentation can help improve intraoperative navigation workflow when planned appropriately. The authors review current literature to help guide surgeon decision making when utilizing navigation. Additionally, tips and techniques for use of navigation are detailed to help avoid common surgeon pitfalls. In general, navigation platforms are classified based on image acquisition and degree of surgeon motion restriction during instrumentation. Imageless platforms often require preoperative images to be uploaded into the navigation system. Image-based systems rely on intraoperative imaging to ensure accuracy of its referencing software. The system then creates a three-dimensional model that allows for visualization of the navigated instrument within the surgical field. Active and passive navigation describe the degree of surgeon free-motion restriction when utilizing navigated instruments. Active navigation platforms, such as most robotic systems, prevent the deviation of the surgeon's instrument from a predetermined trajectory. Passive navigation does not restrict surgeon motion and the projected trajectory of the instrumented can be displayed on a three-dimensional model.

The Application of Intraoperative Computed Tomography in Surgical Management of Temporomandibular Joint Ankylosis

PURPOSE

To investigate the application and value of intraoperative computed tomography (CT) in the surgical management of temporomandibular joint (TMJ) ankylosis.

PATIENTS AND METHODS

Patients who underwent surgery of TMJ ankylosis with the aid of intraoperative CT scan from July 2016 to December 2018 were retrospectively studied. Demographics, type of ankylosis, surgical method, intraoperative CT scan time, radiographic evidence, the CT-directed revision rate, and clinical outcomes were analyzed.

RESULTS

Four patients (5 sides) were successfully operated with the aid of intraoperative CT imaging, and CT-directed revisions were made in 3 of them during surgery. The average time spent in CT scanning was (10.2 ± 3.3) minutes. No surgical complications were noted, and a good satisfaction rate (with an average maximum mouth opening of 38.8 mm and no recurrence during the follow-up period) was obtained.

CONCLUSIONS

Intraoperative CT scanning is a helpful tool in the evaluation of the radiographic result of TMJ ankylosis, and a real-time revision could be made. It increased the precision and safety of the surgery of TMJ ankylosis.

Radiation exposure of a mobile 3D C-arm with large flat-panel detector for intraoperative imaging and navigation - an experimental study using an anthropomorphic Alderson phantom

Background

Intraoperative 3-dimensional (3D) navigation is increasingly being used for pedicle screw placement. For this purpose, dedicated mobile 3D C-arms are capable of providing intraoperative fluoroscopy-based 3D image data sets. Modern 3D C-arms have a large field of view, which suggests a higher radiation exposure. In this experimental study we therefore investigate the radiation exposure of a new mobile 3D C-arm with large flat-panel detector to a previously reported device with regular flat-panel detector on an Alderson phantom.

Methods

We measured the radiation exposure of the Vision RFD 3D (large 30 × 30 cm detector) while creating 3D image sets as well as standard fluoroscopic images of the cervical and lumbar spine using an Alderson phantom. The dosemeter readings were then compared with the radiation exposure of the previous model Vision FD Vario 3D (smaller 20 × 20 cm detector), which had been examined identically in advance and published elsewhere.

Results

The larger 3D C-arm induced lower radiation exposures at all dosemeter sites in cervical 3D scans as well as at the sites of eye lenses and thyroid gland in lumbar 3D scans. At ​​male and especially female gonads in lumbar 3D scans, however, the larger 3D C-arm showed higher radiation exposures compared with the smaller 3D C-arm. In lumbar fluoroscopic images, the dosemeters near/in the radiation field measured a higher radiation exposure using the larger 3D C-arm.

Conclusions

The larger 3D C-arm offers the possibility to reduce radiation exposures for specific applications despite its larger flat-panel detector with a larger field of view. However, due to the considerably higher radiation exposure of the larger 3D C-arm during lumbar 3D scans, the smaller 3D C-arm is to be recommended for short-distance instrumentations (mono- and bilevel) from a radiation protection point of view. The larger 3D C-arm with its enlarged 3D image set might be used for long instrumentations of the lumbar spine. From a radiation protection perspective, the use of the respective 3D C-arm should be based on the presented data and the respective application.

Role of 3D intraoperative imaging in orthopedic and trauma surgery

Intraoperative three-dimensional (3D) imaging is now feasible because of recent technological advances such as 3D cone-beam CT (CBCT) and flat-panel X-ray detectors (FPDs). These technologies reduce the radiation dose to the patient and surgical team. The aim of this study is to review the advantages of 3D intraoperative imaging in orthopedic and trauma surgery by answering the following 5 questions: What are its technical principles? CBCT with a FPD produces non-distorted digital images and frees up the surgical field. The high quality of these 3D intraoperative images allows them to be integrated into surgical navigation systems. Human-robot comanipulation will likely follow soon after. Conventional multislice CT technology has also improved to the point where it can be used in the operating room. What can we expect from 3D intraoperative imaging and which applications have been validated clinically? We reviewed the literature on this topic for the past 10 years. The expected benefits were determined during the implantation of pedicular screws: more accurate implantation, fewer surgical revisions and time savings. There are few studies in trauma or arthroplasty cases, as robotic comanipulation is a more recent development. What is the tolerance for irradiation to the patient and surgical team? The health drawbacks are the harmful radiation-induced effects. The deterministic effects that we will develop are correlated to the absorbed dose in Gray units (Gy). The stochastic and carcinogenic effects are related to the effective dose in milliSievert (mSv) of linear evolution without threshold. The International Commission on Radiological Protection (ICRP) states that irradiation for medical purposes with risk of detriment is acceptable if it is justified by an optimization attempt. The radioprotection limits must be known but do not constitute opposable restrictions. The superiority of intraoperative 3D imaging over fluoroscopy has been demonstrated for spine surgery and sacroiliac screw fixation. How does the environment need to be adapted? The volume, access, wall protection and floor strength of the operating room must take into account the features of each machine. The instrumentation implants and need for specialized staff result in additional costs. Not every system can track movements during the CBCT acquisition thus transient suspension of assisted ventilation may be required. Is it financially viable? This needs to be calculated based on the expected clinical benefits, which mainly correspond to the elimination of expenses tied to surgical revisions. Our society's search for safety has driven the investments in this technology. LEVEL OF EVIDENCE: V, Expert opinion.

Computer-assisted Surgery for Scaphoid Fracture

The computer-assisted surgery (CAS) has significantly improved the accuracy, reliability and outcomes of traumatic, spinal, nerve surgery and many other operations with a less invasive way. The application of CAS for scaphoid fractures remains experimental. The related studies are scanty and most of them are cadaver researches. Some intrinsic defects from the registration procedure, scan and immobilization of limbs may inevitably result in deviations. Some deviations become more obvious with operations of small bones (such as scaphoid) although they are acceptable for spine and other orthopedic surgeries. We reviewed the current literatures on the applications of CAS for scaphoid operation and summarized technical principles, scan and registration methods, immobilization of limbs and their outcomes. On the basis of the data, we analyzed the limitations of this technique and envisioned its future development.

Head-mounted display augmented reality to guide pedicle screw placement utilizing computed tomography

PURPOSE

Augmented reality has potential to enhance surgical navigation and visualization. We determined whether head-mounted display augmented reality (HMD-AR) with superimposed computed tomography (CT) data could allow the wearer to percutaneously guide pedicle screw placement in an opaque lumbar model with no real-time fluoroscopic guidance.

METHODS

CT imaging was obtained of a phantom composed of L1-L3 Sawbones vertebrae in opaque silicone. Preprocedural planning was performed by creating virtual trajectories of appropriate angle and depth for ideal approach into the pedicle, and these data were integrated into the Microsoft HoloLens using the Novarad OpenSight application allowing the user to view the virtual trajectory guides and CT images superimposed on the phantom in two and three dimensions. Spinal needles were inserted following the virtual trajectories to the point of contact with bone. Repeat CT revealed actual needle trajectory, allowing comparison with the ideal preprocedural paths.

RESULTS

Registration of AR to phantom showed a roughly circular deviation with maximum average radius of 2.5 mm. Users took an average of 200 s to place a needle. Extrapolation of needle trajectory into the pedicle showed that of 36 needles placed, 35 (97%) would have remained within the pedicles. Needles placed approximated a mean distance of 4.69 mm in the mediolateral direction and 4.48 mm in the craniocaudal direction from pedicle bone edge.

CONCLUSION

To our knowledge, this is the first peer-reviewed report and evaluation of HMD-AR with superimposed 3D guidance utilizing CT for spinal pedicle guide placement for the purpose of cannulation without the use of fluoroscopy.

3D printing from microfocus computed tomography (micro-CT) in human specimens: education and future implications

Microfocus CT (micro-CT) is an imaging method that provides three-dimensional digital data sets with comparable resolution to light microscopy. Although it has traditionally been used for non-destructive testing in engineering, aerospace industries and in preclinical animal studies, new applications are rapidly becoming available in the clinical setting including post-mortem fetal imaging and pathological specimen analysis. Printing three-dimensional models from imaging data sets for educational purposes is well established in the medical literature, but typically using low resolution (0.7 mm voxel size) data acquired from CT or MR examinations. With higher resolution imaging (voxel sizes below 1 micron, <0.001 mm) at micro-CT, smaller structures can be better characterised, and data sets post-processed to create accurate anatomical models for review and handling. In this review, we provide examples of how three-dimensional printing of micro-CT imaged specimens can provide insight into craniofacial surgical applications, developmental cardiac anatomy, placental imaging, archaeological remains and high-resolution bone imaging. We conclude with other potential future usages of this emerging technique.