Use Of Intraoperative Fluoroscopy Research Articles

Survey of terminology used for the intraoperative direction of C-arm fluoroscopy

Orthopedic surgeons depend on the intraoperative use of fluoroscopy to facilitate procedures across all subspecialties. The versatility of the C-arm fluoroscope allows acquisition of nearly any radiographic view. This versatility, however, creates the opportunity for difficulty in communication between surgeon and radiation technologist. Poor communication leads to delays, frustration and increased exposure to ionizing radiation. There is currently no standard terminology employed by surgeons and technologists with regards to direction of the fluoroscope. The investigation consisted of a web-based survey in 2 parts. Part 1 was administered to the membership of the Canadian Orthopedic Association, part 2 to the membership of the Canadian Association of Medical Radiation Technologists. The survey consisted of open-ended or multiple-choice questions examining experience with the C-arm fluoroscope and the terminology preferred by both orthopedic surgeons and radiation technologists. The survey revealed tremendous inconsistency in language used by orthopedic surgeons and radiation technologists. It also revealed that many radiation technologists were inexperienced in operating the fluoroscope. Adoption of a common language has been demonstrated to increase efficiency in performing defined tasks with the fluoroscope. We offer a potential system to facilitate communication based on current terminology used among Canadian orthopedic surgeons and radiation technologists.

The use of intra-operative fluoroscopy for tibial tunnel placement in anterior cruciate ligament reconstruction.

ObjectivesOur aim was to assess the use of intra-operative fluoroscopy in the assessment of the position of the tibial tunnel during reconstruction of the anterior cruciate ligament (ACL).MethodsBetween January and June 2009 a total of 31 arthroscopic hamstring ACL reconstructions were performed. Intra-operative fluoroscopy was introduced (when available) to verify the position of the guidewire before tunnel reaming. It was only available for use in 20 cases, due to other demands on the radiology department. The tourniquet times were compared between the two groups and all cases where radiological images lead to re-positioning of the guide wire were recorded. The secondary outcome involved assessing the tibial interference screw position measured on post-operative radiographs and comparing with the known tunnel position as shown on intra-operative fluoroscopic images.ResultsOf the 20 patients treated with fluoroscopy, the imaging led to repositioning of the tibial guide wire before reaming in three (15%). The mean tourniquet time with intra-operative fluoroscopy was 56 minutes (44 to 70) compared with 51 minutes (42 to 67) for the operations performed without. Six patients (30%) had post-operative screw positions that were > 5% more posterior than the known position of the tibial tunnel.ConclusionIntra-operative fluoroscopy can be effectively used to improve the accuracy of tibial tunnel positions with minimal increase in tourniquet time. This study also demonstrates the potential inaccuracy associated with plain radiological assessment of tunnel position.

Use of Intraoperative Fluoroscopy During Laparotomy to Identify Fragments of Retained Essure Microinserts: Case Report

In previous case-reports of Essure microinsert perforation, the microinsert was successfully removed at laparoscopy. Herein is discussed the scenario of persistent pelvic pain over several years after an apparently successful laparoscopic retrieval of a perforating right-sided microinsert. In the interim, the patient underwent 2 unsuccessful exploratory laparotomy procedures in an attempt to retrieve additional microinsert fragments that had perforated the uterus. Successful management of Essure microinsert perforation in this patient ultimately required use of intraoperative fluoroscopy. Surgeons performing laparoscopy or laparotomy to retrieve Essure microinserts that have perforated should be aware that these are not always visible to the naked eye, and there should be a low threshold to use intraoperative fluoroscopy to ensure that all perforating fragments have been removed.

Accuracy of Intraoperative Fluoroscopy with and without Laser Guidance in Foot and Ankle Surgery

The use of intraoperative fluoroscopy in orthopedic surgery involves frequent exposure to ionizing radiation in the operating room. Although a number of studies have found radiation exposure to orthopedic surgeons to be well below recommended doses, the long-term effects of low-dose radiation are not well known. Thus, all effective practical methods should be undertaken to reduce the exposure to radiation. Our purpose was to determine whether the use of a laser-aiming device improves the accuracy of intraoperative fluoroscopy to reduce, by implication, radiation exposure in the operating room. From March to October 2004, there were 92 consecutive cases requiring use of fluoroscopy in the orthopedic foot and ankle service of the authors' institution. The number of accurate and inaccurate images with or without the presence of a radiology technician and a laser-aiming device were compared. The accuracy of imaging with the laser-aiming device was higher than the imaging without the device (p < 0.001). The accuracy of the images obtained by the surgeon was higher than the technicians' images when laser guidance was used (p= 0.027). There was no significant difference between the images obtained by the surgeon or the technicians when the aiming device was not used (p = 0.09). The use of a laser-aiming device to help position during fluoroscopy is recommended in an effort to reduce radiation exposure in foot and ankle surgery.

Free Hand Pedicle Screw Placement in the Thoracic Spine without Any Radiographic Guidance : Technical Note, a Cadaveric Study

Thoracic pedicle screw fixation techniques are still controversial for thoracic deformities because of possible complications including neurologic deficit. Methods to aid the surgeon in appropriate screw placement have included the use of intraoperative fluoroscopy and/or radiography as well as image-guided techniques. We describe our technique for free hand pedicle screw placement in the thoracic spine without any radiographic guidance and present the results of pedicle screw placement analyzed by computed tomographic scan in two human cadavers. This free hand technique of thoracic pedicle screw placement performed in a step-wise, consistent, and compulsive manner is an accurate, reliable, and safe method of insertion to treat a variety of spinal disorders, including spinal deformity.

Anterior Approach in THA Improves Outcomes: Opposes

Total hip arthroplasty (THA) can be performed through multiple surgical approaches, including anterior, anterolateral, lateral, transtrochanteric, posterolateral, posterior, and the 2-incision technique. The overwhelming majority of THAs today are performed through a posterolateral approach, which has many advantages: it can be extended without difficulty, it is expeditious, it results in reduced blood loss and little muscle damage, and recovery is rapid. The major disadvantage of the approach is its increased dislocation rate, which has become less of a problem with the advent of larger femoral heads and dual-mobility acetabular components. The anterior approach is another hip approach with advantages and disadvantages. One disadvantage is the need for a special table on which to perform the procedure, which can cost ≥$100,000. Many surgeons also recommend the use of intraoperative fluoroscopy with this approach, which prolongs surgery and adds possible draping contamination during the fluoroscopy. Exposure of the femur may be difficult with this approach, especially in patients with increased body mass index. The operative time also tends to be longer with this approach, as exposure may be more tedious. The published data report significant complications with this procedure.

Minimally Invasive Fluoro-Navigation Screw Fixation for the Treatment of Pelvic Ring Injuries

Intensive use of intraoperative fluoroscopy is mandatory to achieve good accuracy and avoid neural or vascular injury and may prolong surgical time and increase exposure-related hazards. New methods of percutaneous treatment in conjunction with innovative fluoroscopy-based computerized navigation have evolved in an attempt to overcome the existing difficulties. This report described our experience in applying fluoroscopic surgical navigation technique and evaluated its clinical application to pelvic ring injuries, including its feasibility, merits and limitations. Twenty-two patients with pelvic ring injuries were treated with percutaneous pubic ramus screw and sacroiliac screw techniques under the guidance of a fluoroscopy-based navigation system. A total of forty-four screws were inserted, including twenty-seven pubic ramus screws and seventeen sacroiliac screws. The average operation time and the average fluoroscopy time per screw were 23.6 minutes and 22.2 seconds respectively. Compared to the final position of the screw, the average deviated distance of wire tip was 2.8 mm and the average trajectory difference was 2.6°. A ventral cortex perforation of the sacrum was found in one sacroiliac screw without any clinical symptoms. No superficial or deep infection occurred. No patient sustained recognized neurologic, vascular, or urologic injury as a result of percutaneous screw fixation of pubic ramus fractures, sacroiliac disruptions, or sacral fractures. Our results showed that fluoroscopy-based navigation technique for the pelvic ring injuries could become a safe and effective alterative method for the treatment of pelvic ring injuries in some selected patients.

Intraoperative imaging in hallux valgus surgery

This prospective study investigates the use of intraoperative fluoroscopy in hallux valgus surgery. To our knowledge there have been no studies questioning the benefit and reliability of intraoperative fluoroscopy in hallux valgus surgery. We performed a prospective investigation of 28 consecutive cases undergoing hallux valgus surgery. Fluoroscopic images were examined intraoperatively and any significant findings documented. A comparison was made between these images and weight bearing films 6 weeks postoperatively to examine their reliability. We excluded those patients that went on to have an Akin osteotomy. There were no unforseen intraoperative events that were revealed by the use of fluoroscopy and no surgical modifications were made as a result of the intraoperative images. The intraoperative films were found to be a reliable representation of the postoperative weight bearing films but a small increase in the hallux valgus angle was noted at 6 weeks and this is thought to be due to stretching of the medial soft tissue repair. Intraoperative fluoroscopy is a reliable technique. This study was performed at a centre which performs approximately 100 hallux valgus operations per year and that should be taken into consideration when reviewing our findings. We conclude that there may be a role for fluoroscopy for surgeons in the early stages of the surgical learning curve and for those that infrequently perform hallux valgus surgery. We cannot, however, recommend that fluoroscopy be used routinely in hallux valgus surgery.

Upper airway obstruction associated with flexed cervical position after posterior occipitocervical fusion

Upper airway obstruction resulting from overflexion fixation of the cervical spine is a rare but life-threatening complication after cervical spine surgery. There are few reports of dyspnea after a posterior cervical fusion. We present the case of a 63-year-old woman with rheumatoid arthritis who developed an upper airway obstruction immediately after an O-C4 fusion. She was reintubated with a fiberoptic scope. Revision surgery allowing the angle to return to the neutral position was performed to ameliorate the overflexion of the cervical spine fixation and the consequent upper airway obstruction. After revision surgery, the upper airway obstruction disappeared. Our experience suggests that intraoperative use of fluoroscopy and extubation with a tube exchanger are recommended to avoid this complication, especially in patients at high risk of upper airway obstruction.

Radiation risk from fluoroscopically-assisted anterior cruciate ligament reconstruction.

Precise tunnel positioning is crucial for success in anterior cruciate ligament (ACL) reconstruction. The use of intra-operative fluoroscopy has been shown to improve the accuracy of tunnel placement. Although radiation exposure is a concern, we lack information on the radiation risk to patients undergoing fluoroscopically-assisted ACL reconstruction with a standard C-arm. The aim of our study was to determine the mean radiation doses received by our patients. Radiation doses were recorded for 18 months between 1 April 2007 and 30 September 2008 for 58 consecutive patients undergoing ACL reconstruction assisted by intra-operative fluoroscopy. Dose area product (DAP) values were used to calculate the entrance skin dose (ESD), an indicator of potential skin damage and the effective dose (ED), an indicator of long-term cancer risk, for each patient. The median age of 58 patients included in data analysis was 28 years (range, 14-52 years), of whom 44 were male (76%). The mean ESD during intra-operative fluoroscopy was 0.0015 +/- 0.0029 Gy. The mean ED was 0.001 +/- 0.002 mSv. No results exceeded the threshold of 2 Gy for skin damage, and the life-time risk of developing new cancer due to intra-operative fluoroscopy is less than 0.0001%. Radiation doses administered during fluoroscopically-assisted ACL reconstruction were safe and do not represent a contra-indication to the procedure.

Radiographic and clinical evaluation of free-hand placement of C-2 pedicle screws

Stabilization of the cervical spine can be challenging when instrumentation involves the axis. Fixation with C1-2 transarticular screws combined with posterior wiring and bone graft placement has yielded excellent fusion rates, but the technique is technically demanding and places the vertebral arteries (VAs) at risk. Placement of screws in the pars interarticularis of C-2 as described by Harms and Melcher has allowed rigid fixation with greater ease and theoretically decreases the risk to the VA. However, fluoroscopy is suggested to avoid penetration laterally, medially, and superiorly to avoid damage to the VA, spinal cord, and C1-2 joint, respectively. The authors describe how, after meticulous dissection of the C-2 pars interarticularis, such screws can be placed accurately and safely without the use of fluoroscopy. Prospective follow-up was performed in 55 consecutive patients who underwent instrumented fusion of C-2 by a single surgeon. The causes of spinal instability and type and extent of instrumentation were documented. All patients underwent preoperative CT or MR imaging scans to determine the suitability of C-2 screw placement. Intraoperatively, screws were placed following dissection of the posterior pars interarticularis. Postoperative CT scans were performed to determine the extent of cortical breach. Patients underwent clinical follow-up, and complications were recorded as vascular or neurological. A CT-based grading system was created to characterize such breaches objectively by location and magnitude via percentage of screw diameter beyond the cortical edge (0 = none; I = < 25% of screw diameter; II = 26-50%; III = 51-75%; IV = 76-100%). One-hundred consecutive screws were placed in the pedicle of the axis by a single surgeon using external landmarks only. In 10 cases, only 1 screw was placed because of a preexisting VA anatomy or bone abnormality noted preoperatively. In no case was screw placement aborted because of complications noted during drilling. Early complications occurred in 2 patients and were limited to 1 wound infection and 1 transient C-2 radiculopathy. There were 15 total breaches (15%), 2 of which occurred in the same patient. Twelve breaches were lateral (80%), and 3 were superior (20%). There were no medial breaches. The magnitude of the breach was classified as I in 10 cases (66.7% of breaches), II in 3 cases (20% of breaches), III in 1 case (6.7%), and IV in 1 case (6.7%). Free-hand placement of screws in the C-2 pedicle can be done safely and effectively without the use of intraoperative fluoroscopy or navigation when the pars interarticularis/pedicle is assessed preoperatively with CT or MR imaging and found to be suitable for screw placement. When breaches do occur, they are overwhelmingly lateral in location, breach < 50% of the screw diameter, and in the authors' experience, are not clinically significant.

Intra-operative Fluoroscopic Measurements to Determine Tibial Tunnel Placement in Anatomical Double Bundle ACL Reconstruction (SS-44)

Intra-operative Fluoroscopic Measurements to Determine Tibial Tunnel Placement in Anatomical Double Bundle ACL Reconstruction (SS-44)

Intraoperative Fluoroscopy-Guided Removal of Orbital Foreign Bodies

To describe the use of intraoperative fluoroscopy as an aid in the removal of radio-opaque orbital foreign bodies. A retrospective interventional case series of 12 patients with orbital foreign bodies that required removal for various indications. All patients underwent orbitotomy and removal of the foreign bodies with the aid of real-time intraoperative fluoroscopic localization. The orbital foreign body was successfully removed without complication in all 12 patients. One patient with ethmoid sinusitis preoperatively had resolution of the infection after surgery. Two patients with extraocular motility deficits preoperatively experienced significant improvement in motility after surgery. Three patients who required MRI studies for unrelated conditions were able to undergo scanning postoperatively without complications. Two patients were combat casualties treated by US medical personnel during Operation Iraqi Freedom. There were no cases of visual or ocular morbidity directly attributable to foreign body removal. Intraoperative fluoroscopy is a valuable tool that can aid in the removal of radio-opaque orbital foreign bodies.

Slipped capital femoral epiphysis: A modern treatment protocol

The treatment of a patient with slipped capital femoral epiphysis begins with an early diagnosis and accurate classification. On the basis of symptom duration, clinical findings and radiographs, slipped capital femoral epiphysis is classified as pre-slip, acute, acute-on-chronic and chronic. The long-term outcome of slipped capital femoral epiphysis is directly related to severity and the presence or absence of avascular necrosis and/or chondrolysis. Therefore, the first priority in the treatment of slipped capital femoral epiphysis is to avoid complications while securing the epiphysis from further slippage. Medical treatment of patients with acute and acute-on-chronic slipped capital femoral epiphysis, as well as those presented in pre-slip stage, is the safest, although time-consuming. Manipulations, especially forced and repeated, are not recommended due to higher avascular necrosis risk. The use of intraoperative fluoroscopy to assist in the placement of internal fixation devices has markedly increased the success of surgical treatment. Controversy remains as to whether the proximal femoral epiphysis in severe, chronic slipped capital femoral epiphysis should be realigned by extracapsular osteotomies or just fixed in situ. The management protocol for slipped capital femoral epiphysis depends on the experience of the surgeon, motivation of the patient and technical facilities.

Inadvertent Retention of Angled Drill Guides After Volar Locking Plate Fixation of Distal Radial Fractures

Advances in locking plate technology have proven especially valuable for fixation of distal radial fractures, and preliminary results have been excellent1-6. However, new technology can sometimes lead to new complications. In some systems, the locking plates are preloaded with angled drill guides to allow for easy placement of locking screws in the proper direction (Fig. 1). The drill guides are designed to be removed prior to closure. We report the cases of three patients in whom the angled drill guides were retained after surgery. Institutional review board approval was obtained for this study, and the patients were informed that data concerning the case would be submitted for publication, and they consented. Fig. 1 The Hand Innovations Distal Volar Radius (DVR) locking plate. The proximal and distal rows are preloaded with angled drill guides. Case 1. A sixty-three-year-old woman sustained a closed distal radial fracture after a fall. Attempted closed reduction was unacceptable, and the patient elected to proceed with open reduction and internal fixation. Fixation consisted of open reduction and application of a Distal Volar Radius (DVR) plate (Hand Innovations, Miami, Florida) with use of intraoperative fluoroscopy. The first formal radiographs were obtained at two-week follow-up in the office showing three retained drill guides. The patient was offered surgery to remove the guides but declined. By six weeks after the operation, she had attained full range of motion of the wrist and had returned to work with no pain. Nine months postoperatively, she presented …

The Use of Intraoperative Fluoroscopy as an Aid for Removal of Radiopaque Intraorbital Foreign Bodies

Two patients with orbital trauma and intraorbital foreign bodies, as seen on a computed tomography scan, were taken to the operating room to rule out occult ruptured globe with possible foreign body removal. The C-arm fluoroscopic unit was employed to obtain real-time images of the foreign body's location in relation to the surgeon's dissection tools and the foreign body was extracted with minimal dissection and operating time. When removal of a foreign body is warranted, intraoperative fluoroscopy can help reduce surgical time and orbital manipulation.

P58. Electromagnetic Pedicle Screw Navigation and Radiation Exposure

BACKGROUND CONTEXT: Accurate placement of pedicle screws is imperative for safe stabilization of the spine. Traditional open techniques of pedicle screw insertion are more frequently being supplanted by minimally invasive techniques that may necessitate an increased use of intraoperative fluoroscopy and thus radiation exposure for the patient, surgeon, and support staff. Electromagnetic field (EMF) based navigation may aide in safe, accurate, and efficient placement of pedicle screws while reducing fluoroscopic demand.

Use of navigation-assisted fluoroscopy to decrease radiation exposure during minimally invasive spine surgery

Background Minimally invasive surgery decreases postoperative pain and disability. However, limited views of the surgical field require extensive use of intraoperative fluoroscopy that may expose the surgical team to higher levels of ionizing radiation. Purpose To assess the feasibility and safety of navigation-assisted fluoroscopy during minimally invasive spine surgery. Study Design A combined cadaveric and human study comparing minimally invasive transforaminal lumbar interbody fusion (MIS TLIF) using navigation-assisted fluoroscopy with standard intraoperative fluoroscopy to determine differences in surgical times and radiation exposures. Methods Eighteen fresh cadaveric spines underwent unilateral MIS TLIF by using either navigation-assisted fluoroscopy or standard fluoroscopy. Times for specific surgical steps were compared. In addition, a prospective short-term evaluation of the intraoperative and perioperative results of 10 patients undergoing navigation-assisted MIS TLIF (NAV group) compared with a retrospective review of 8 patients undergoing MIS TLIF performed by using standard fluoroscopy (FLUORO group). Results In the cadaveric study, the times were similar between the NAV group and the FLUORO group for most key steps. No statistically significant differences were obtained for approach, exposure, screw insertion, facetectomy/decompression, or total surgical times. Statistically significant differences were obtained for the setup time and total fluoroscopy time. The setup time for the NAV group averaged 9.67 (standard deviation [SD], 3.74) minutes compared with 4.78 (SD, 2.11) minutes for the FLUORO group (p=.034). The total fluoroscopy time was higher for the FLUORO group compared with the NAV group (41.9 seconds vs. 28.7 seconds, p=.042). Radiation exposure was undetectable when navigation-assisted fluoroscopy is used (NAV group). In contrast, an average 12.4 milli-REM (mREM) of radiation exposure is delivered to the surgeon during unilateral MIS TLIF procedure without navigation (FLUORO group). In the clinical series, the total fluoro time for the NAV group was 57.1 seconds (SD, 37.3; range, 18–120) compared with 147.2 seconds (SD, 73.3; range, 73–295) for FLUORO group (p=.02). No statistically significant differences are noted for operating time, estimated blood loss, or hospital stay. No inadvertent durotomies, postoperative weakness, or new radiculopathy were noted in the NAV group. One inadvertent durotomy was encountered in the FLUORO group that was repaired intraoperatively without clinical sequelae. Conclusion The use of navigation-assisted fluoroscopy is feasible and safe for minimally invasive spine surgery. Radiation exposure is decreased to the patient as well as the surgical team.

Feasibility of near real-time image-guided sinus surgery using intraoperative fluoroscopic computed axial tomography

One of the main limitations of image-guided surgery is that navigation relies on the use of a CT scan obtained before surgery and is unable to be updated during the procedure. A software addition has been developed to allow reconstruction of CT-like images from a series of fluoroscopic scans and integrate these into an image-guided system (GE Healthcare Surgical Navigation, Lawrence, MA). We report our initial experience with a series of patients undergoing intraoperative fluoroscopic navigation in sinus surgery. After institutional review board clearance, we prospectively studied 14 consecutive patients undergoing image-guided sinus surgery with the use of intraoperative fluoroscopy. All patients had preoperative and postoperative fluoroscopic images reconstructed into CT-like images. By the conclusion of the study, images were adequate in quality and accurate navigation was achieved. Real-time image-guided sinus surgery using fluoroscopy is feasible. Future studies will need to focus on defining the procedures that could benefit, such as tumor resection, to enhance patient safety during these operations.

Radiation Exposure in Hand Surgery: Mini Versus Standard C-Arm

The use of intraoperative fluoroscopy in hand surgery is common. Two types of fluoroscopic units are available: the mini C-arm and the standard C-arm. There is little literature on the radiation exposure from the mini C-arm, therefore, the primary goal of this study was to quantify and compare the amount of radiation exposure to members of the surgical team (surgeon, first assistant, nurse, anesthesiologist) using both standard and mini C-arms in a simulated wrist surgery setup. Mini C-arm positioning was also examined to determine the safest configuration to minimize radiation exposure to surgeons. Radiation dosimeters were used to test 2 commercially available fluoroscopy units in a simulated wrist surgery setup with a cadaveric upper extremity. Several different configurations of the C-arms were tested to determine radiation exposure rates to surgeons and the operating room staff. The mean in-beam radiation exposures with the use of the mini and standard C-arms were 3,720 mR/h and 6,540 mR/h, respectively. The mini C-arm had universally less radiation exposure than the standard C-arm in the clinical configurations tested. The safest configuration of mini C-arm use to minimize radiation exposure was with the surgeon standing on the image intensifier side of the unit as compared with the source side. Mini C-arm radiation exposure to the hands, groin, chest, and thyroid of the operating surgeons were well below the National Council of Radiation Protection and Measurement's annual dose limits. In the clinical configurations tested in this study the mini C-arm had lower radiation exposures than the standard C-arm. To reduce radiation exposure maximally surgeons should stand behind the lead-encased image intensifier and should use techniques to reduce exposure.