C-arm fluoroscopy in orthopaedic surgical practice

Artificial Intelligence-Based Surgery Support Model Using Intraoperative Radiographs for Assessing the Acetabular Component Angle

BACKGROUND

This study aimed to develop an artificial intelligence (AI)-based surgical support model for assessing the acetabular component angle using intraoperative radiographs during total hip arthroplasty and verify its accuracy.

METHODS

A total of 268 hips were analyzed. At first, 268 preoperative and intraoperative antero-posterior pelvic radiographs were amplified to 536. These radiographs were used to create a learning model to estimate the acetabular component angle from the radiographs intraoperatively. The ground truth was the anteversion and inclination angles obtained from the computed tomography (CT)-based navigation system intraoperatively. Bone landmarks on the preoperative and intraoperative radiographs were manually annotated. The distances and angles between each landmark were used as predictor variables. The estimation accuracy was assessed for internal and external test datasets. Mean absolute error (MAE) and R2 values were used as accuracy measures.

RESULTS

The MAE and R2 for the internal test set showed 2.19 and 0.850 for anteversion, and 1.18 and 0.805 for inclination, respectively. The MAE and R2 for the external test set showed 2.78 and 0.789 for anteversion, and 1.56 and 0.744 for inclination, respectively.

CONCLUSION

We developed an AI-based surgical support model for accurately assessing the acetabular component angle using intraoperative radiographs. Excellent estimation accuracy was confirmed for the external test set. In the future, the model may help to reduce the risk of adverse postoperative events.

Assessment of radiation exposure risks in patients undergoing elastic stable intramedullary nailing: Insights from intraoperative fluoroscopy

INTRODUCTION

Elastic stable intramedullary nailing (ESIN) is a well-defined and appropriate treatment of choice for long bone fractures. Despite its benefits, the risk of cancer from imaging devices is of particular concern for younger adults. So, this survey was conducted to estimate the doses administered to patients undergoing ESIN of long bone fractures utilizing a 2-dimensional (2D) C-arm fluoroscopy machine during surgery, as well as the carcinogenic risk associated with the use of the machine.

METHODS

This study was conducted on 147 patients who required ESIN for long-bone fractures. Patients' demographic data, surgical data and imaging information were collected. For each patient, the organ doses and the effective doses were computed with the Monte Carlo PCXMC 2.0 simulation software. The cancer risk models proposed in the Biological Effects of Ionizing Radiation VII (BEIR VII) Phase 2 report were used to evaluate the risk of exposure-induced cancer death (REID) values.

RESULTS

For all patients, the highest organ dose was delivered to the gonads. The mean effective dose was 0.026 ± 0.015 mSv and 1.3E-04 ± 1E-04 mSv for ESIN of femur and tibia fractures, respectively. Males had a mean REID of 1 per million, while females had a mean REID of 0.19 per million. The younger males had considerably higher REID values. The effective dose was significantly correlated with age, gender, and irradiation time.

CONCLUSION

Low levels of effective doses and cancer risks associated with the utilization of the fluoroscopy machine in current practice were found in ESIN treatment of long-bone fractures.

IMPLICATIONS FOR PRACTICE

This outcome will help to raise surgeons' awareness of radiation risks and encourage them to initiate measures to keep radiation dose and exposure time as low as reasonably achievable.

Intraoperative Radiation Exposure During Midfoot Charcot Reconstruction

While radiation exposure in foot and ankle surgery varies by procedure, attempts to minimize this hazard remain imperative to protect patients and surgeons. Hindfoot deformity correction employs significant radiation through intraoperative fluoroscopy, however, a paucity of data exists concerning Charcot reconstruction. This investigation describes and compares radiation exposure across varying Charcot pathology and fixation constructs. A retrospective chart review of patients undergoing midfoot Charcot reconstruction under large C-arm assistance from 2016-2022 was conducted. Demographics, pathology-specific, and intervention-specific variables were recorded and compared among midfoot reconstructions. The threshold for statistical significance was set at p ≤ .05. Among 40 patients, the average midfoot radiation exposure and fluoroscopy times were 9.5 ± 5.39 mGy and 256.64 ± 130.67 seconds, respectively. There existed no statistically significant difference in radiation exposure (p = .32) or fluoroscopy times (p = .71) among the different midfoot constructs. There existed a statistically significant relationship between radiation exposure with weight (p = .01) body mass index (p = .03) and number of stages (p = .04). Similarly, a relationship existed between fluoroscopy time with weight (p = .02), body mass index (p = .03), and number of beams/screws (p = .003). Due to the complexity of Charcot reconstruction coupled with multiple robust types of fixation, surgeons must remain cognizant of fluoroscopy usage. Moreover, providers who routinely perform Charcot reconstruction should wear personal protective equipment to protect against radiation.

Optimization of radiation doses for open lumbar spinal fusion using C-arm fluoroscopy and impact on radiation-induced cancer: a pilot study

PURPOSE

Intraoperative fluoroscopy use is essential during spinal fusion procedures. The amount of radiation dose should always be minimized. This study aimed to determine the feasibility of halving the frame rate from 12.5 to 6.25 frames per second (fps) and to quantify the reduction in the risk of developing radiation-induced cancer.

METHODS

This pilot study included 34 consecutive patients operated for open lumbar posterolateral fusion (PLF) with or without transforaminal lumbar interbody fusion (TLIF). C-arm modes were changed from half-dose (12.5 frames per second (fps), group I) to quarter-dose (6.25 fps, group II). Age, body mass index, surgical procedure, number of treated levels, and complications were collected. Kerma area product (KAP), cumulative air kerma (CAK), and fluoroscopy time were compared. Effective dose and radiation-induced cancer risk were estimated.

RESULTS

Eighteen and 16 patients were, respectively, included in group I and II. Demographic, surgical data, and fluoroscopy time were similar in both groups. However, CAK, KAP, and effective dose were significantly lower in group II, respectively, 0.56 versus 0.41 mGy (p = 0.03), 0.09 versus 0.06 Gy cm2 (p = 0.04), and 0.03 versus 0.02 mSv (p = 0.04). Radiation-induced cancer risk decreased by 47.7% from 1.49 × 10-6 to 7.77 × 10-7 after optimization. No complications were recorded in either group.

CONCLUSION

This study demonstrates the feasibility of setting 6.25 fps for TLIF with and without PLF. By halving the fps, radiation-induced cancer risk could be almost divided by two, without compromising surgical outcome. Finally, after optimization, the risk of developing radiation-induced cancer was less than one in a million.

Low-dose pulsed vs standard pulsed fluoroscopy during ERCP to reduce radiation without change in image quality: Prospective randomized study

Background and study aims Endoscopic retrograde cholangiopancreatography (ERCP) poses the risk of radiation exposure (RE) to patients and staff and increases the risk of adverse biological effects such as cataracts, sterility, and cancer. Newer fluoroscopy equipment (C-Arm) provides options to limit radiation in the form of lower radiation dose and frame rate or time-limited "pulsed" settings. However, the impact of lower settings on image quality has not been assessed, and no standard protocol exists for fluoroscopy settings used during ERCP. Patients and methods This was a single-center, double-blind, prospective randomized study of consecutive adult patients undergoing standard-of-care ERCP at a tertiary academic medical center. Patients were randomized into two groups: 1) standard-dose pulsed and 2) low-dose pulsed. Pulsed mode (8 fps) was defined as x-ray exposure either in the manufacturer standard-dose or low-dose settings limited to 3 seconds each time the foot-operated switch was depressed. Results Seventy-eight patients undergoing ERCP were enrolled and randomized. No difference in age, gender, or body mass index was found between the two groups. No significant difference in image quality was found between standard-dose and low-dose fluoroscopy P = 0.925). The low-dose group was exposed to significantly less radiation when compared with standard-dose P < 0.05). Fluoroscopy time (minutes) was similar in both groups (2.0 vs 1.9), further suggesting that group assignment had no impact on image quality or procedure time. Conclusions Low-dose pulsed fluoroscopy is a reliable method that substantially reduces radiation without compromising image quality or affecting procedure or fluoroscopy times. This underscores the need for standardization in ERCP fluoroscopy settings to limit radiation exposure.

Intraoperative Angle Measurement of Anatomical Structures: A Systematic Review

Ensuring precise angle measurement during surgical correction of orientation-related deformities is crucial for optimal postoperative outcomes, yet there is a lack of an ideal commercial solution. Current measurement sensors and instrumentation have limitations that make their use context-specific, demanding a methodical evaluation of the field. A systematic review was carried out in March 2023. Studies reporting technologies and validation methods for intraoperative angular measurement of anatomical structures were analyzed. A total of 32 studies were included, 17 focused on image-based technologies (6 fluoroscopy, 4 camera-based tracking, and 7 CT-based), while 15 explored non-image-based technologies (6 manual instruments and 9 inertial sensor-based instruments). Image-based technologies offer better accuracy and 3D capabilities but pose challenges like additional equipment, increased radiation exposure, time, and cost. Non-image-based technologies are cost-effective but may be influenced by the surgeon's perception and require careful calibration. Nevertheless, the choice of the proper technology should take into consideration the influence of the expected error in the surgery, surgery type, and radiation dose limit. This comprehensive review serves as a valuable guide for surgeons seeking precise angle measurements intraoperatively. It not only explores the performance and application of existing technologies but also aids in the future development of innovative solutions.

Orthopaedic surgeons' knowledge and practice of radiation safety when using fluoroscopy during procedures: A narrative review

OBJECTIVES

The fluoroscopy environment poses a potential occupational radiation exposure risk to theatre personnel. Risks can be mitigated with effective application of radiation protection knowledge and methods. This review aimed to determine the link between orthopaedic surgeon's knowledge and the use of appropriate safety methods when using fluoroscopy.

KEY FINDINGS

A keyword search of three databases discovered six articles, totalling 2209 orthopaedic surgeons, who completed surveys to assess knowledge on various aspects of radiation safety and training. Participants had varying levels of experience. Moreover 1981 participants always wore a lead gown (89 %), while only 1052 participants wore thyroid protection (47 %). 449 participants (20 %) received some form of training.

CONCLUSION

Although surveys asked a range of questions it appeared that there was low knowledge of the ALARP principles. Usage of protective equipment is a legal requirement and thus was observed throughout, however, there were a number of incidences of disregarding some protective measures. Although there appeared to be limited knowledge surrounding radiation protection measures and lack of training provided, no clear link was demonstrated between compliance with protective methods and knowledge of the risks.

IMPLICATIONS FOR PRACTICE

Formal and continuous training should be provided for the enhancement of knowledge to ensure the safety of all staff and help prevent the long-term effects of ionising radiation when using fluoroscopy.

Does radiation exposure during pediatric supracondylar humeral fracture surgery change according to the C-arm position? A comparison of two different techniques

INTRODUCTION

In the surgical treatment of supracondylar humeral fractures (SHF), the surgeon has to stand right next to the fluoroscopy device, so it is very important to know how to use it in the most appropriate way to reduce radiation exposure. The aim of this study was to investigate the effect of using C-arm in uniplanar (inverted) and biplanar (standard-horizontal) configurations on (1) the radiation exposure to the surgeon, and (2) surgical time and fluoroscopy exposure time.

MATERIAL AND METHODS

This prospective randomised study was conducted on 20 patients who underwent fluoroscopy during closed reduction and percutaneous pinning for a SHF. In the first configuration, the C-arm was inverted and the image intensifier was used as a surgical table. In the second configuration, the C-arm was used biplanar. The operations were performed by 5 surgeons, with each surgeon using each method only twice. During the operation, to find a value closed to direct radiation exposure measurement was made by attaching a dosimeter to the wrist and scatter radiation exposure was measured by attaching a dosimeter to the neck and waist of the surgeons. The operation time and fluoroscopy exposure time were determined.

RESULTS

The duration of operations performed with the biplanar C-arm position and the fluoroscopy exposure time in operations performed with the uniplanar method were found to be statistically significantly longer (p = 0.001). The measurements on the dosimeter worn on the neck of surgeons were found to be statistically significantly higher while using the uniplanar C-arm configuration (p = 0.001). There was no statistically significant difference between the dosimeter measurements on the wrists and waists of the surgeons and the C-arm configurations (p = 0.820; p = 0.185).

CONCLUSIONS

Although the use of biplanar C-arm has no effect on radiation exposure to the surgeon's wrist, the most important advantages are that the neck area is exposed to less radiation and it shortens the fluoroscopy time so the use of a biplanar C-arm can be recommended.

LEVEL OF EVIDENCE

Level II.

3D Visualisation of the Spine

The 3D visualisation of the spine is thought of from multiple viewpoints. Firstly, radiological imaging is considered, with plain radiography, CT and MRI imaging discussed in detail with relevant applications to spinal surgery.3D printing can be used in spinal surgery with multiple applications including education, pre-operative planning for complex cases and making patient-specific guides and implants. The rapidly growing field of intraoperative navigation and robotics have been discussed, in addition to their benefits and limitations within spinal surgery, as well as some technical tips.An understanding of relevant anatomy and biomechanics is necessary for any surgeon, and so this chapter describes the key concepts to be familiar with, particularly the spinal motion segment and the different methods for classifying spinal injuries and how that relates to stability. The concepts discussed have been brought together by applying this knowledge to some interesting clinical cases. They highlight the importance of 3D visualisation of the spine, which must be considered throughout the decision-making process when managing patients. Spinal surgeons use multiple imaging modalities, knowledge of anatomy and biomechanics, as well as considering the need for navigation in more complex cases, all on a daily basis. With the advancement of technology available for 3D visualisation of the spine, we will be able to improve patient outcomes even further in the future.

[Intraoperative imaging of children and adolescents, for selected fractures and in follow-up after conservative and operative treatment : Part 2 of the results of a nationwide online survey of the Pediatric Traumatology Section of the German Trauma Society]

The indication for radiographic examinations in pediatric and adolescent trauma patients should follow ALARA (as low as reasonably achievable). Because of the effect of radiation on the growing sensitive tissues of these young patients, a strict indication should always be given for radiation use and during controls after fracture repair.

METHODS

An online survey by the Pediatric Traumatology Section (SKT) of the German Trauma Society (DGU) from Nov. 15, 2019, to Feb. 29, 2020, targeting trauma, pediatric, and general surgeons and orthopedic surgeons.

RESULTS

Participants: 788. Intraoperative applications: Collimation 50% always, postprocessing for magnification 40%, pulsed x-ray 47%, and 89% no continuous fluoroscopy; 63% osteosynthesis never directly on image intensifier. Radiographic controls after implant removal never used by 24%. After operated supracondylar humerus fracture, controls are performed up to 6 times. After distal radius greenstick fracture, 40% refrain from further X-ray controls, after conservatively treated clavicular shaft fracture, 55% refrain from further controls, others X-ray several times. After nondisplaced conservatively treated tibial shaft fracture, 63% recommend radiographic control after 1 week in two planes, 24% after 2 weeks, 37% after 4 weeks, and 32% after 6 weeks.

DISCUSSION

The analysis shows that there is no uniform radiological management of children and adolescents with fractures among the respondents. For some indications for the use of radiography, the benefit does not seem evident. The ALARA principle does not seem to be consistently followed.

CONCLUSION

Comparing the documented results of the survey with the consensus results of the SKT, differences are apparent.

Comparison of surgical outcomes of C1-2 fusion surgery between O-arm-assisted operation and C-arm assisted operation in children with atlantoaxial rotatory fixation

Objective

Placement of the pedicle screw is technically challenging during C1-2 fusion surgery in children and different intraoperative image-guided systems have been developed to reduce the risk of screw malposition. The purpose of the present study was to compare surgical outcomes between C-arm fluoroscopy and O-arm navigated pedicle screw placement in the treatment of atlantoaxial rotatory fixation in children.

Methods

We retrospectively evaluated charts of all consecutive children with atlantoaxial rotatory fixation who underwent C-arm fluoroscopy or O-arm navigated pedicle screw placement from April 2014 to December 2020. Outcomes including operative time, estimated blood loss (EBL), accuracy of screw placement (Neo's classification) and completed fusion time were evaluated.

Results

A total of 340 screws were placed in 85 patients. The accuracy of screw placement of the O-arm group was 97.4%, which was significantly higher than that of the C-arm group (91.8%). Both groups had satisfied bony fusion (100%). Statistical significance (230.0 ± 34.6 ml for the C-arm group and 150.6 ± 47.3 ml for the O-arm group, p < 0.05) was observed with respect to the median blood loss. There were no statistically significant difference (122.0 ± 16.5 min for the C-arm group and 110.0 ± 14.4 min for the O-arm group, p = 0.604) with respect to the median operative time.

Conclusion

O-arm-assisted navigation allowed more accurate screw placement and less intraoperative blood loss. Both groups had satisfied bony fusion. O-arm navigation did not prolong the operative time despite the time required for setting and scanning.

Investigation of radiation dose around C-arm fluoroscopy and relevant cancer risk to operating room staff

This study aimed to evaluate the ambient dose equivalent around a C-arm device during spinal surgeries and determine the optimum locations for the surgeon and staff to keep radiation exposure as low as reasonably achievable. Furthermore, cancer risk incidence was estimated using the excess relative risk (ERR) concept of the biologic effects of ionizing radiation VII report for operating room (OR) staff. A lateral projection of the C-arm setup was considered in the current study. The ambient dose equivalent rate was measured using an electronic dosimeter in 30° steps all around for 1, and 1.6-m heights as well as 1, and 2-m distances away from a water tank (scattering medium). By assuming a typical workload, the annual ambient dose and a maximum number of permissible operations were determined. For a worst-case scenario, the dose was used to estimate the ERR for various organs including prostate, ovary, breast, lung, thyroid, and colon for attained ages of 35, 40, and 50 years. The maximum ambient dose equivalent rate was seen at 330° and 30° (about 600 µSv/h at 1 m height and a distance of 1 m from the scattering medium). The corresponding permissible workload for an OR staff was about 30,660 operations. Based on the obtained results, 60° next to the image intensifier was the optimum position for the surgeon, while 30° next to the tube was the worst position because of backscattered radiation. The ERR results showed that the lung and colon have the highest cancer risk incidence among the considered organs for both males and females, respectively.

Improved Radiation Exposure Monitoring of Orthopaedic Residents After Institution of a Personalized Lead Protocol

Background:

Radiation exposure of orthopaedic residents should be accurately monitored to monitor and mitigate risk. The purpose of this study was to determine whether a personalized lead protocol (PLP) with a radiation monitoring officer would improve radiation exposure monitoring of orthopaedic surgery residents.

Materials and Methods:

This was a retrospective case-control study of 15 orthopaedic surgery residents monitored for radiation exposure during a 2-year period (March 2017 until February 2019). During the first 12-month period (phase 1), residents were given monthly radiation dosimeter badges and instructed to attach them daily to the communal lead aprons hanging outside the operating rooms. During the second 12-month period (phase 2), a PLP (PLP group) was instituted in which residents were given lead aprons embroidered with their individual names. A radiation safety officer was appointed who placed the badges monthly on all lead aprons and collected them at the end of the month, whereas faculty ensured residents wore their personalized lead apron. Data collected included fluoroscopy use time and radiation dosimeter readings during all orthopaedic surgeries in the study period.

Results:

There were 1,252 orthopaedic surgeries using fluoroscopy during phase 1 in the control group and 1,269 during phase 2 in the PLP group. The total monthly fluoroscopy exposure time for all cases averaged 190 minutes during phase 1 and 169 minutes during phase 2, with no significant difference between the groups (p < 0.45). During phase 1, 73.1% of the dosimeters reported radiation exposure, whereas during phase 2, 88.7% of the dosimeters reported radiation exposure (p < 0.001). During phase 1, the average monthly resident dosimeter exposure reading was 7.26 millirems (mrem) ± 37.07, vs. 19.00 mrem ± 51.16 during phase 2, which was significantly higher (p < 0.036).

Conclusions:

Institution of a PLP increased the compliance and exposure readings of radiation dosimeter badges for orthopaedic surgery residents, whereas the actual monthly fluoroscopy time did not change. Teaching hospitals should consider implementing a PLP to more accurately monitor exposure.

Level of Evidence:

3.

Occupational ionizing radiation-induced skin injury among orthopedic surgeons: A clinical survey

BACKGROUND

This study aimed to assess orthopedic surgeons' attitudes and behaviors toward occupational radiation exposure and investigate the prevalence of occupational radiation-induced skin injury among orthopedic surgeons. Similarly, risk factors for the presence of radiation-induced skin injury were investigated.

METHODS

Overall, 108 orthopedic surgeons were administered self-reported questionnaires about occupational radiation exposure, and their hands were then photographed. Their fields of expertise were classified into spine, arthroplasty, sports medicine, hand, oncology, rheumatoid arthritis, pediatric orthopedic, and resident. Dermatologists evaluated the surgeons' skin conditions and classified into 3 grades of injury: grade 0, no clinical symptoms; grade 1, careful observation required; and grade 2, detailed examination required. Logistic regression analysis was performed to investigate the factors related to the presence of radiation-induced skin injury. Crude and adjusted logistic regression analysis using the backward stepwise selection method was similarly conducted. Receiver operating characteristic curve (ROC) analysis was performed to estimate the predictive power of exposure time, occupational period, and accumulated annual exposure time for radiation-induced skin injury.

RESULTS

In total, 93.5% of the surgeons were careful about occupational radiation exposure, of which 76.8% used a dosimeter. Skin changes in the hands were self-reported by 42.5% of the surgeons, and radiation-induced skin injury was diagnosed in 31.4%. The accuracy of the self-reported skin changes was 100% for grade 2 and 61.5% for grade 1. Adjusted regression analysis showed that dermatologists' diagnosis-related factors were self-reported skin changes (odds ratio [OR] 3.1) and spine surgeons (OR 3.2). ROC analysis demonstrated that an occupational period >21 years and an accumulated exposure time >6696 min were considered risk factors, with ORs of 4.07 and 5.99, respectively.

CONCLUSIONS

Orthopedic surgeons, particularly spine surgeons, should be regularly examined by dermatologists early in their careers for early detection of radiation-induced skin injury on the hands.

How molecular imaging will enable robotic precision surgery : The role of artificial intelligence, augmented reality, and navigation

Molecular imaging is one of the pillars of precision surgery. Its applications range from early diagnostics to therapy planning, execution, and the accurate assessment of outcomes. In particular, molecular imaging solutions are in high demand in minimally invasive surgical strategies, such as the substantially increasing field of robotic surgery. This review aims at connecting the molecular imaging and nuclear medicine community to the rapidly expanding armory of surgical medical devices. Such devices entail technologies ranging from artificial intelligence and computer-aided visualization technologies (software) to innovative molecular imaging modalities and surgical navigation (hardware). We discuss technologies based on their role at different steps of the surgical workflow, i.e., from surgical decision and planning, over to target localization and excision guidance, all the way to (back table) surgical verification. This provides a glimpse of how innovations from the technology fields can realize an exciting future for the molecular imaging and surgery communities.

The Use of Intraoperative Digital Radiography Alignment Software to Assess Implant Placement in Total Hip Arthroplasty

PURPOSE OF REVIEW

Total hip arthroplasty (THA) is a highly successful surgery with growing rates of utilization in the USA, but surgical outliers leading to postoperative complications remain a concern. There is need for a standard system of accurate, predictable intraoperative evaluation to decrease component positioning outliers. Many current intraoperative imaging systems have shown promise, but there are drawbacks that have led to slow adoption. Digital radiography, in conjunction with Radlink™ technology, is a potential solution to this problem. This review summarizes the clinical application and scientific literature regarding the use of Radlink™ in THA.

RECENT FINDINGS

Traditional surgeon-directed component placement can result in surgical outliers. This is especially true not only among low-volume arthroplasty surgeons, but can also occur with experienced, high-volume surgeons. Digital radiography allows for more precise and accurate placement of the acetabular cup in a targeted range in an effort to improve THA outcomes. Intraoperative images are obtained quickly, and they are accurate when compared to postoperative images. Additionally, the use of Radlink™ results in a significant decrease in leg length and femoral offset outliers. The adoption of Radlink™ technology in THA can significantly decrease surgical outliers, especially errors in acetabular cup placement, leg length, and femoral offset. Digital radiography avoids many of the previous aversions to intraoperative imaging as it produces a fast, reliable image with little radiation exposure and minimal interruption to workflow. There is the potential for Radlink™ use to provide superior patient outcomes, as a decrease in surgical outliers can minimize implant malpositioning with resultant need for revision THAs. Radlink™ may also provide benefit in analyzing other parameters, such as component sizing.

Contamination of the Mini C-Arm During Foot and Ankle Surgery

BACKGROUND

Many orthopedic surgeries utilize intraoperative fluoroscopy. The mini C-arm is an advantageous device as it can be easily used without the need for a dedicated radiology technician. However, there are concerns that the mini C-arm may represent a potential source of contamination and subsequent postoperative infection. Previous investigations of standard C-arm drapes have shown high rates of contamination. Similar contamination rates would be even more concerning for the mini C-arm as it requires physically maneuvering the machine. This study aimed to determine the rate of mini C-arm drape contamination and identify high-risk areas.

METHODS

Fifty foot and ankle surgeries requiring the use of mini C-arm fluoroscopy were included. Eight locations on the mini C-arm drape were sampled at the conclusion of each procedure. Culture Q-swabs were used for sampling defined locations. Swab samples were then assessed for bacterial growth on a 5% blood agar plate using a semiquantitative technique.

RESULTS

In 70% of surgical cases, contamination was observed in at least 1 location. Six of the 8 evaluated locations were found to have significantly higher contamination in comparison with their corresponding negative controls (Mann-Whitney U test, P < .05). The "outer portion of the upper arm" (location 1) exhibited bacteria growth in 26% (P < .0001) of cases. The "superior portion of the x-ray source" (location 2) exhibited growth in 30% (P < .0001) of cases. These were the highest-risk areas for contamination and were both significantly more likely to be involved than the "inferior portion of the x-ray source" and "superior portion of the beam receiver," locations 4 and 5, respectively. Fourteen percent (7/50) C-arm cases and 1.72% (1/58) Achilles tendon surgery control cases developed surgical site infection (P = .0234; OR, 9.27).

CONCLUSION

Bacterial contamination of the mini C-arm drape was found to be common after foot and ankle procedures. Contamination was more prevalent on the outer ring areas of the C-arm, both at the emitter and receiver.

LEVEL OF EVIDENCE

Level III, prospective cohort study.

Level of Supervision and Radiation Exposure of Senior Orthopedic Residents During Surgical Treatment of Proximal Femur Fracture

The sustained use of intraoperative fluoroscopy has led to increased use of minimally invasive surgical techniques, enhanced surgeon proficiency, improved anatomic corrections, reduced patient morbidity, earlier functional recovery, and decreased length of hospital stay. As a result, orthopedic attending surgeons and residents are exposed to more radiation, increasing the risk of cancer and radiation-induced cataracts compared with the general population and those who work in other surgical specialties. The magnitude of radiation exposure depends on the susceptibility of the tissues affected, medical specialty, the position of the C-arm, distance from the radiation beam, level of difficulty of the surgical procedure, surgeon experience, level of resident training, and level of supervision by the attending surgeon. However, little information is available on the effect of supervision level on radiation exposure for orthopedic senior residents. The goal of this study was to investigate whether level of supervision by the attending surgeon affects the radiation exposure of orthopedic senior residents during surgical treatment of proximal femur fracture with cephalomedullary nail fixation. This retrospective cohort study was performed from January 2019 to March 2019. No significant relationship between supervision level and radiation exposure of senior residents was observed. Supervision level does not significantly affect radiation exposure for senior residents; therefore, the implementation of standardized training in radiation safety may be a more essential measure to decrease radiation exposure. [Orthopedics. 2021;44(3):e402-e406.].

Arthroscopy-Assisted Management of Schatzker Type III Lateral Tibial Plateau Fracture With Interference Screw Fixation

Tibial plateau fractures occur in both old and young patients and may be caused by low-energy trauma, as well as high-energy trauma. Owing to the variety of injury mechanisms and fracture patterns, tibial plateau fractures are very challenging to treat. One of the most demanding fractures is the type III fracture according to the Schatzker classification, which is a pure depression of the lateral tibial plateau. Treatment with open surgical procedures is associated with vast soft-tissue trauma and prolonged recovery after surgery. Although soft-tissue trauma is minimized and visual control is improved throughout arthroscopy-assisted surgical procedures, internal fixation using buttress plates or lag screws is still required to reduce and fix the depressed plateau. We present an arthroscopy-assisted technique of reduction and fixation of the lateral tibial plateau fracture with 3 BioComposite interference screws (Arthrex, Munich, Germany) that provides a high amount of stability and reduces patient immobilization, allowing for faster rehabilitation.

The effectiveness of a free-standing lead-shield in reducing spine surgeon radiation exposure during intraoperative 3-dimensional imaging

BACKGROUND

CONTEXT Intraoperative three-dimensional (3D) computed tomography (CT) imaging has become increasingly popular in spine surgery. Previous spine surgeon radiation exposure research has focused largely on procedures using fluoroscopy, however, few studies have been performed on the subject since the introduction of the 3D imaging systems. As a result, concerns have re-emerged over surgeon radiation exposure and the effectiveness of operating room (OR) protocols for decreasing workplace radiation. Current radiation safety guidelines require surgeons wear full body protective lead while any type of radiation is being administered during surgery. As a result, local institutions do not allow for the use of free-standing lead shields for sole radiation protection in the operating room. However, there is no data available to demonstrate whether the additional personal lead is required, or if in fact the lead shield alone is sufficient.

PURPOSE

This study investigated the effectiveness of a free-standing lead shield in reducing spine surgeon radiation exposure in the operating room during intraoperative imaging.

STUDY DESIGN/SETTING

A prospective clinical research study at a large, tertiary care center.

PATIENT SAMPLE

Twenty-seven patients undergoing instrumented spinal procedures between June and August 2019.

OUTCOME MEASURES

Fluoroscopy time, total fluoroscopy dose delivered, 3D dose delivered, total 3D spins, number of HD spins, number of standard spins, number of fluoroscopic images, number of spine levels operated on, patient size setting, shield distance from patient, radiation dose in front of shield, radiation dose behind shield.

METHODS

Twenty-seven instrumented spinal procedures using the O-Arm Imaging System (Medtronic, Minneapolis, MN) were observed to determine radiation exposure to a spine surgeon standing behind a lead shield in the OR. Two thermoluminescent dosimeters were used to measure scatter radiation in front of and behind lead shields. Both fluoroscopy and intraoperative CT based radiation exposure was recorded. The dosimeter readings were compared to determine the degree of radiation attenuation by the lead shield. Regression analysis of the exposure values from behind the shield, shield distance from the patient, and radiation dose delivered by the imaging system was utilized to estimate the number of cases required to surpass annual exposure limits. Case numbers were calculated for the highest "worst case" and "average case" exposure values. The safe annual occupation exposure limit determined by the National Council on Radiation Protection is five roentgen equivalent man (rem) or 50,000 microsieverts (μSv).

RESULTS

Average surgeon radiation exposure per case was 0.694 μSv (SD: 0.501, Range: 0.105-2.167) behind the lead shield compared to 14.577 μSv (SD: 9.864, Range: 2.185-44.492) in front of the lead shield. The average radiation dose reduction by the lead shield was 13.962 μSv (SD: 9.49, Range: 2.08-42.72) per case, which is equivalent to an average of 95.65% (SD: 1.71) radiation attenuation by lead shielding. If surgeons stand behind lead shields in the OR, the annual number of 3D image-guided spinal procedures required to surpass exposure limits is 15,479 and 67,060 based on "worst case" and "average case" analyses, respectively.

CONCLUSIONS

Our study demonstrates standing behind intraoperative lead shields is very effective at decreasing radiation exposure to surgeons. Additionally, surgeon radiation doses behind lead shielding fall far below annual exposure limits. Surgeons should not need additional protective equipment when a lead shield is used.

Intraoperative Fluoroscopy Reduces Complication and Reoperation Rate in Facial Fractures

Purpose: The purpose of this study is to evaluate surgical outcomes of facial fractures after the introduction of intraoperative radiology. Methods: An historic cohort of patients without intraoperative fluoroscopy (IOF) was compared with a prospective cohort of patients with IOF. Main outcomes were postoperative complications and reoperation rate. Results: There were 51 in the non-IOF group and 49 in the IOF group. In the group with IOF 10 patients required intraoperative revisions (20.46%). Overall postoperative complication rate was higher in the non-IOF group (25.49% vs. 6.12%) due to the significantly higher bone-related complication rate (15.69% vs. 2.04%). Reoperation rate was also higher in the non-IOF group (11.76% vs. 0%). Conclusion: This study demonstrates that IOF reduces bone-related complication and reoperation rate by allowing correction of surgical errors immediately during surgery.