Surgeon's and patient's radiation exposure during percutaneous thoraco-lumbar pedicle screw fixation: A prospective multicenter study of 100 cases

An Integrated 3-Dimentional Navigation System Increases the Accuracy, Efficiency, and Safety of Percutaneous Thoracolumbar Pedicle Screw Placement in Minimally Invasive Approaches: A Randomized Cadaveric Study

STUDY DESIGN

Cadaveric study.

OBJECTIVES

The purpose of this study was to compare a novel, integrated 3D navigational system (NAV) and conventional fluoroscopy in the accuracy, efficiency, and radiation exposure of thoracolumbar percutaneous pedicle screw (PPS) placement.

METHODS

Twelve skeletally mature cadaveric specimens were obtained for twelve individual surgeons. Each participant placed bilateral PS at 11 segments, from T8 to S1. Prior to insertion, surgeons were randomized to the sequence of techniques and the side (left or right). Following placement, a CT scan of the spine was obtained for each cadaver, and an independent reviewer assessed the accuracy of screw placement using the Gertzbein grading system. Outcome metrics of interest included a comparison of breach incidence/severity, screw placement time, total procedure time, and radiation exposure between the techniques. Bivariate statistics were employed to compare outcomes at each level.

RESULTS

A total of 262 screws (131 using each technique) were placed. The incidence of cortical breaches was significantly lower with NAV compared to FG (9% vs 18%; P = .048). Of breaches with NAV, 25% were graded as moderate or severe compared to 39% in the FG subgroup (P = .034). Median time for screw placement was significantly lower with NAV (2.7 vs 4.1 min/screw; P = .012), exclusive of registration time. Cumulative radiation exposure to the surgeon was significantly lower for NAV-guided placement (9.4 vs 134 μGy, P = .02).

CONCLUSIONS

The use of NAV significantly decreased the incidence of cortical breaches, the severity of screw breeches, screw placement time, and radiation exposure to the surgeon when compared to traditional FG.

Lumbar discectomy and fusion: Organs’ dose and effective dose estimation using Monte Carlo simulation

In this study, the effect of patient- and procedure-related parameters on organs' dose (OD), peak skin dose (PSD) and effective dose (ED) during lumbar discectomy and fusion (LDF) was assessed. Intra-operative parameters obtained from 102 LDFs were inserted into VirtualDose-IR software implementing sex-specific and BMI-adjustable anthropomorphic phantoms for dosimetric calculations. Fluoroscopy time (FT), kerma-area product (KAP), cumulative and incident air-kerma (K_air) were also recorded from the dosimetric report of the mobile C-arm. An increase in KAP, K_air, PSD and ED was found for male or higher BMI patients, multi-level or fusion or L5/S1 procedures. However, a significant difference was found only for PSD and incident K_air between normal and obese patients and for FT between discectomy and discectomy and fusion procedures. The spleen, kidneys and colon received the highest doses. The BMI have a significant impact only for kidneys, pancreas, and spleen doses when comparing obese to overweight and for urinary bladder when comparing overweight to normal patients. Multi-level and fusion procedures resulted in significantly higher doses for lungs, heart, stomach, adrenals, gallbladder and kidneys, while pancreas and spleen doses significantly increased only for multi-level procedures. Additionally, a significant increase was found only for urinary bladder, adrenals, kidneys, and spleen ODs when comparing L5/S1 and L3/L4 levels. The mean ODs were lower compared to the literature. These data may aid neurosurgeons in optimising exposure techniques during LDF to keep patients' dose as low as is practicably possible.

Can intraoperative radiation dose in percutaneous posterior thoracolumbar internal fixation be reduced by impedancemetry-guided pedicle sighting? A prospective randomized study

INTRODUCTION

Percutaneous spine surgery is on the rise; the main drawback is iterative irradiation of the care team in theater. The aim of the present study was to compare intraoperative radiation dose in percutaneous posterior thoracolumbar internal fixation (PPTLIF) using impedancemetry-guided pedicle sighting by the PediGuard device (SpineGuard®) versus gold-standard free-hand sighting.

MATERIAL AND METHODS

A single-center, single-surgeon continuous prospective randomized study was conducted from September 2017 to April 2018. Dose-area product (DAP, in cGy.cm²) was recorded at the end of pedicle sighting and end of surgery in the free-hand control group and the impedancemetry group. Pedicle screw position was studied on postoperative CT scan.

RESULTS

Sixteen patients were included in either group after 2 had been excluded. The groups were comparable for age, gender, body-mass index (BMI), indication and number of instrumented levels. Mean DPA at end of sighting and end of procedure was respectively 147.4 cGy.cm² and 230.9 cGy.cm² in the control group and 171.1 cGy.cm² and 280.7 cGy.cm² in the PediGuard group (p> 0.05). Screw positioning on CT was comparable in the 2 groups.

CONCLUSION

In the present study, the PediGuard device did not reduce intraoperative radiation dose. The correlation between radiation dose and BMI was confirmed.

LEVEL OF EVIDENCE

II; prospective randomized study.

Marker Screw Utilization for Minimally Invasive Transforaminal Lumbar Interbody Fusion (MS-MIS TLIF): Promises and Advantages

Background and Objective: Minimally Invasive Transforaminal Lumbar Interbody Fusion (MIS-TLIF) has been investigated and shown excellent short- and long-term outcomes. In this paper, we describe a new MIS-TLIF technique and pedicle screw insertion using a marker screw as a guidance method. Moreover, we report perioperative, postoperative, and patient-related outcomes. In addition, this paper outlines major differences in radiation exposure, cost effectiveness and accuracy of Marker Screw Minimally Invasive Transforaminal Interbody Fusion (MS-MIS TLIF) compared to other techniques. We report our technique to share our knowledge and experience with the aim of achieving a better MIS-TLIF that would help both surgeons and patients. Materials and Methods: A prospective case series was conducted between October 2018 and February 2021. Patients undergoing MS-MIS TLIF with marker screws were consecutively included. The surgery did not exceed two levels. The patients’ medical records were reviewed, and the included patients were asked to complete two outcome-questionnaires before surgery and at the six-month visit. The surgical technique is described in this paper. Results: A total of 37 patients were recruited. The mean age was 57.35 ± 12.8 years, and more than half of the patients were females. The most common indications for surgery were degenerative disc disease and spondylolisthesis, with the typical level at L4–5. The operative time was 3.02 ± 0.83 h, while the estimated blood loss was 127.7 ± 71.1 mL. The average time for ambulation and hospitalization was 1 ± 1.1 and 2.84 ± 1.4 days, respectively. The patients described significant improvement in both questionnaires. No screw-related complications or screw revisions were needed up to two years of follow-up. Conclusions: The use of marker screws for pedicle screw placement through a minimally invasive fashion is shown to be a promising technique that can overcome many drawbacks, including cost, operative time, and radiation exposure. Performing MS-MIS TLIF can achieve a 360- degree fusion compared to percutaneous MIS-TLIF.

Ultrasound-guided Jamshidi needle puncture to reduce radiation exposure during percutaneous pedicle screw placement: study protocol for a randomised controlled trial

INTRODUCTION

Percutaneous pedicle screw placement (PPSP) is a minimally invasive procedure highly dependent on fluoroscopic guidance, which results in increased radiation exposure and prolonged operative time. Ultrasound can image the lumbar paravertebral anatomy and the needle trajectory in real time, which may help reduce the use of fluoroscopy and radiation dose in PPSP. We will conduct a parallel randomised controlled trial to mainly investigate the effect of ultrasound guidance in radiation reduction during PPSP.

METHODS AND ANALYSIS

A total of 42 patients will be recruited and randomly assigned to the intervention group and the control group at a 1:1 ratio. In the intervention group, we will use ultrasound in combination with fluoroscopy to guide the insertion of the Jamshidi needles. In the control group, PPSP will be performed under conventional fluoroscopic guidance. The primary outcomes are the cumulative fluoroscopy time (s), radiation dose (mGy) and exposure times of screw placement. The secondary outcomes are insertion time of guidewire, rate of pedicle perforation, rate of facet joint violation, visual analogue scale for back pain, Oswestry Disability Index and complications. The participants, outcome assessors and data analysts will be blinded to allocation.

ETHICS AND DISSEMINATION

The trial was approved by the research ethics committee of Shengjing Hospital, China Medical University. The results will be presented at academic seminars and submitted for publication in peer-reviewed journals.This study involves human participants and was approved by Research Ethics Committee of Shengjing Hospital, China Medical University reference number：2022PS704K. Participants gave informed consent to participate in the study before taking part.

TRIAL REGISTRATION NUMBER

ChiCTR2200057131.

Bone conductivity and spine fluoroscopy, Hand-Eye-Ear dialogue, during pedicle screw positioning: a new human cognitive system for precision and radiation-decrease; better than artificial intelligence and machine learning system?

PURPOSE

There is an increasing need for pedicle screw positioning while decreasing radiation exposure. This study compares intra-operative radiation dose using posterior internal fixation using impedancemetry-guided pedicle positioning by the Pediguard system versus standard free-hand sighting when surgery was performed with a trainee or expert surgeon.

MATERIAL AND METHODS

Using the electrical properties of bone, the Pediguard detects iatrogenic penetration of the pedicle wall and gives auditory feedback to the surgeon. A single centre, two surgeons (one experienced and the other novice) conducted a continuous prospective randomized study for one year. Twenty patients were randomized into one group (free-hand control group) receiving pedicle instrumentation without the use of the Pediguard and the second group receiving pedicle instrumentation with the use of the Pediguard. The total screw placement times and fluoroscopic times for each screw was recorded and pedicle screw position was analyzed on post-operative CT scan.

RESULTS

Among the 104 screwed pedicles, 22 unrecognized perforations were detected by CT scan, while no perforation signal was observed intra-operatively. Only one perforation was greater than 2 mm. The overall screwing time was 4.33 ± 1.2 minutes per screw for experienced surgeon and 5.84 ± 2.5 minutes per screw for the novice. Pediguard did not increased significantly the time (0.3 mn per screw) for the experienced surgeon, but the time with Pediguard was longer (2 mn more per screw) for the novice surgeon, particularly at the thoracic level. The overall fluoroscopic average time per screw for the experienced surgeon is 5.8 ± 2.3 s and 10.4 ± 4.5 s for the novice surgeon. For the novice surgeon, radiation time reduced from 12 (without Pediguard) to 6 s (with Pediguard). There was no significant difference for the experienced surgeon in terms of improvement in radiation time with the use of Pediguard.

CONCLUSION

The overall time was longer for the novice surgeon with the Pediguard system, but allowed to decrease by 50% the fluoroscopy time.

Robot-guided versus freehand fluoroscopy-guided minimally invasive transforaminal lumbar interbody fusion: a single-institution, observational, case-control study

OBJECTIVE

The use of robotics in spinal surgery has gained popularity because of its promising accuracy and safety. ROSA is a commonly used surgical robot system for spinal surgery. The aim of this study was to compare outcomes between robot-guided and freehand fluoroscopy-guided instrumentation in minimally invasive surgery (MIS)–transforaminal lumbar interbody fusion (TLIF).

METHODS

This retrospective consecutive series reviewed 224 patients who underwent MIS-TLIF from March 2019 to April 2020 at a single institution. All patients were diagnosed with degenerative pathologies. Of those, 75 patients underwent robot-guided MIS-TLIF, and 149 patients underwent freehand fluoroscopy-guided MIS-TLIF. The incidences of pedicle breach, intraoperative outcomes, postoperative outcomes, and short-term pain control were compared.

RESULTS

The patients who underwent robot-guided surgery had a lower incidence of pedicle breach (0.27% vs 1.75%, p = 0.04) and less operative blood loss (313.7 ± 214.1 mL vs 431.6 ± 529.8 mL, p = 0.019). Nonsignificant differences were observed in operative duration (280.7 ± 98.1 minutes vs 251.4 ± 112.0 minutes, p = 0.056), hospital stay (6.6 ± 3.4 days vs 7.3 ± 4.4 days, p = 0.19), complications (intraoperative, 1.3% vs 1.3%, p = 0.45; postoperative surgery-related, 4.0% vs 4.0%, p = 0.99), and short-term pain control (postoperative day 1, 2.1 ± 1.2 vs 1.8 ± 1.2, p = 0.144; postoperative day 30, 1.2 ± 0.5 vs 1.3 ± 0.7, p = 0.610). A shorter operative duration for 4-level spinal surgery was found in the robot-guided surgery group (388.7 ± 107.3 minutes vs 544.0 ± 128.5 minutes, p = 0.047).

CONCLUSIONS

This retrospective review revealed that patients who underwent robot-guided MIS-TLIF experienced less operative blood loss. They also benefited from a shorter operative duration with higher-level (> 3 levels) spinal surgery. The postoperative outcomes were similar for both robot-guided and freehand fluoroscopy-guided procedures.

Minimising radiation exposure to the surgeon in minimally invasive spine surgeries: A systematic review of 15 studies

BACKGROUND

Intraoperative imaging in minimally invasive spinal surgeries is associated with significant radiation exposure to surgeons, which overtime can lead to serious health hazards including malignancy. In this study, the authors conducted a systematic review to evaluate the efficacy of navigation assisted fluoroscopy methods on radiation exposure to the surgeon in minimally invasive spine surgeries, percutaneous endoscopic lumbar discectomy/percutaneous endoscopic transforaminal discectomy versus minimally invasive spine transforaminal lumbar interbody fusion (PELD/PETD versus MIS-TLIF).

METHODS

A systematic literature search was conducted using PUBMED/MEDLINE on 20th July, 2020. Inclusion criteria were applied according to study design, surgical technique, spinal region, and language. Data extracted included lumbar segment, average operation time (min), fluoroscopic time (s), and radiation dose (μSV), efficacy of modified navigation versus conventional techniques; on reducing operation, fluoroscopy times and effective radiation dose.

RESULTS

Fifteen studies (ten prospectives, and five retrospectives) were included for quantitative analysis. PELD recorded a shorter operation time (by 126.3min, p<0.001) and fluoroscopic time (by 22.9s, p=0.3) than MIS-TLIF. The highest radiation dose/case (μSV) for both techniques were recorded at the surgeon's: finger, chest, neck and eye. The effective dose for MIS-TLIF was 30μSV higher than PELD. Modified navigation techniques recorded a shorter operation time (by 15.9min, p=0.3); fluoroscopy time (by 289.8s, p=0.3); effective radiation dose (by 169.5μSV, p=0.3) than conventional fluoroscopy methods.

DISCUSSION

This systematic literature review showed that although navigation assisted fluoroscopy techniques are superior to conventional methods in minimising radiation exposure, lack of statistical significance warrants future randomised controlled trials, to solidify their efficacy in reducing radiation related hazards.

Prospective analysis of intraoperative radiation dose in foot and ankle surgery using mini-C-arm fluoroscopy. Continuous series of 1064 procedures

INTRODUCTION

Foot and ankle surgeons make daily use of mini-C-arm fluoroscopes. The present study aimed to quantify associated radiation doses.

HYPOTHESIS

X-ray exposure for foot and ankle surgeons using a mini-C-arm fluoroscope is below the nuclear safety authority authorized doses of 20 mSv/year for the whole body and crystalline lens, 150 mSv/year for the thyroid and 500 mSv/year for the skin and limbs.

MATERIAL AND METHODS

A single-center, single-surgeon prospective series was treated between February 2014 and December 2017. Doses emitted by the mini-C-arm (15cm field) were recorded during 1,064 operations. Doses received by the surgeon were recorded by 3 passive dosimeters (thorax, eyes and hands) and 1 active dosimeter. The significance threshold was set at p<0.05.

RESULTS

A total of 64.4% of procedures concerned the forefoot, 35.3% the hindfoot and ankle, and 0.3% were strictly percutaneous. Mean dose-area product (DAP) per procedure was 3.9 cGy/cm²±7: in forefoot surgery, 1.1 cGy/cm²±0.9, and in hindfoot and ankle surgery 8.7 cGy/cm²±9.7 (p<0.05), for mean irradiation times of 7.6s±5.3 and 36.7s±35.5 respectively and image numbers 4.1±2.7 and 18.7±20.5. Total ankle replacement was associated with the highest doses: 20.1 cGy/cm²±14.7. Mean daily active dosimetry was 2.2μSv±1.4. Mean annual dose to the hand, crystalline lens and deep (Hp(10)) and shallow (Hp(0.07)) whole body was respectively 1.28 mSv, 0.6 mSv, 0.31 mSv and 0.19 mSv. The highest annual exposure was recorded for the hands: 2.68 mSv in 2015. There was a significant linear relationship between daily active dosimetry and daily emission: daily active dosimetry=(DAP×0.11)+0.54, for a correlation coefficient of 0.77.

DISCUSSION/CONCLUSION

The exposure of foot and ankle surgeons using mini-C-arms was well below threshold, and also lower than in the literature.

LEVEL OF EVIDENCE

IV.

Comparison of Clinical Outcomes After Transforaminal Interbody Fusion Using Cortical Bone Trajectory versus Percutaneous Pedicle Screw Fixation

OBJECTIVE

The study aim was to compare clinical outcomes between patients undergoing transforaminal lumbar interbody fusion (TLIF) using percutaneous pedicle screw (PPS) and cortical bone trajectory (CBT) by a single surgeon.

METHODS

This was a retrospective matched-cohort study of 77 patients (mean age, 71.7 years; 56% female) who underwent TLIF using CBT or PPS. Thirty-nine consecutive patients in the CBT group and 38 patients in the PPS group were matched for age, sex, and fused levels. All CBT screws were inserted by using a three-dimensional patient-specific guide (MySpine MC, Medacta). Perioperative outcomes of operative time, estimated blood loss, numeric rating scale scores, and serum concentration of creatine kinase were compared between the 2 groups. At 1 year postoperatively, clinical outcomes and radiographic outcomes, including cage subsidence, screw loosening, and fusion rates, were compared between the 2 groups.

RESULTS

The numeric rating scale scores on postoperative days 3 and 7 and serum creatine kinase levels on postoperative days 1 and 3 were significantly lower in the CBT group than in the PPS group (all P < 0.005). There were no significant intergroup differences in operation time and estimated blood loss. At postoperative 1 year, there were no significant differences in cage subsidence, screw loosening, and fusion rates between the CBT group and PPS group. Clinical outcomes were equivalent between the 2 groups.

CONCLUSIONS

The CBT technique using three-dimensional patient-specific guides resulted in lower perioperative pain and quicker recovery after surgery, which suggests that CBT is a less invasive procedure than PPS.

[Effectiveness of simultaneous and staged minimally invasive dorsal decompression-stabilization procedures in patients with lumbar spine degenerative diseases]

Minimally invasive procedures reduce the trauma of spine surgery. However, they are associated with high complexity of manipulations, long learning curve, need for expensive equipment for intraoperative navigation and significant irradiation. Various options for surgical approaches are being developed to reduce irradiation of medical staff and patients, surgery time and the number of drugs administered for general anesthesia. Simultaneous surgical interventions (SiSI) is one of these options.

OBJECTIVE

To compare the effectiveness of simultaneous and staged minimally invasive dorsal decompression-stabilization procedures in patients with lumbar spine degenerative diseases.

MATERIAL AND METHODS

A prospective study included 67 patients (41 men and 26 women) aged 48 (34; 56) years who underwent a single-level minimally invasive spinal root decompression and transforaminal interbody fusion via Wiltse posterior-lateral approach. Two study groups were distinguished: group I (simultaneous surgical interventions, SiSI) (n=29), in which guide spokes and transpedicular screws were installed simultaneously by two surgeons within one x-ray session from two sides; group II (staged surgical interventions, StSI) (n=38), in which staged transpedicular stabilization was performed (decompression side followed by contralateral side). Mean follow-up was 14 months in group I and 20 months in group II. We considered intraoperative fluoroscopy and irradiation dose, duration of surgery and anesthesia with calculation of doses of opioid drugs, blood loss, time of activation, hospital-stay and perioperative morbidity. Clinical outcomes were studied in long-term postoperative period.

RESULTS

Simultaneous approach ensured less time of intraoperative fluoroscopy (p=0.029) and irradiation dose (p=0.035), duration of surgery (p=0.01) and anesthesia (p=0.02), amount of opioid drugs during anesthesia (p=0.017). Blood loss, duration of activation and hospitals-stay were similar in both groups (p=0.35, p=0.12 and p=0.57, respectively). There was comparable improvement in VAS score of pain in the lumbar spine and lower extremities in both groups (p=0.63 and p=0.31, respectively). According to SF-36 questionnaire, there was no between-group difference in physical and psychological components (p=0.44 and p=0.72, respectively). There was significantly greater number of adverse effects of anesthesia in the StSI group (26.2% vs. 6.8%, p=0.003). At the same time, the number of surgical postoperative complications was similar in both groups (3.4% vs. 5.3%, p=0.62).

CONCLUSION

Simultaneous minimally invasive dorsal decompression-stabilization procedures have some significant advantages over staged approach regarding intraoperative parameters and adverse effects of anesthesia in patients with lumbar spine degenerative diseases. Nevertheless, there were similar clinical data and small incidence of surgical perioperative complications.

State of the art advances in minimally invasive surgery for adult spinal deformity

Adult spinal deformity (ASD) can be associated with substantial suffering due to pain and disability. Surgical intervention for achieving neural decompression and restoring physiological spinal alignment has shown to result in significant improvement in pain and disability through patient-reported outcomes. Traditional open approaches involving posterior osteotomy techniques and instrumentation are effective based on clinical outcomes but associated with high complication rates, even in the hands of the most experienced surgeons. Minimally invasive techniques may offer benefit while decreasing associated morbidity. Minimally invasive surgery (MIS) for ASD has evolved over the past 20 years, driven by improved understanding of open procedures along with novel technique development and technologic advancements. Early efforts were hindered due to suboptimal outcomes resulting from high pseudarthrosis, inadequate correction, and fixation failure rates. To address this, multi-center collaborative groups have been established to study large numbers of ASD patients which have been vital to understanding optimal patient selection and individualized management strategies. Different MIS decision-making algorithms have been described to better define appropriate candidates and interbody selection approaches in ASD. The purpose of this state of the review is to describe the evolution of MIS surgery for adult deformity with emphasis on landmark papers, and to discuss specific MIS technology for ASD, including percutaneous pedicle screw instrumentation, hyperlordotic grafts, three-dimensional navigation, and robotics.

Evaluation of surgeon and patient radiation exposure by imaging technology in patients undergoing thoracolumbar fusion: systematic review of the literature

BACKGROUND CONTEXT

Minimally invasive spine techniques are becoming increasingly popular owing to their ability to reduce operative morbidity and recovery times. The downside to these new procedures is their need for intraoperative radiation guidance.

PURPOSE

To establish which technologies provide the lowest radiation exposure to both patient and surgeon.

STUDY DESIGN/SETTING

Systematic review OUTCOME MEASURES: Average intraoperative radiation exposure (in mSv per screw placed) to surgeon and patient. Average fluoroscopy time per screw placed.

METHODS

We reviewed the available English medical literature to identify all articles reporting patient and/or surgeon radiation exposure in patients undergoing image-guided thoracolumbar instrumentation. Quantitative meta-analysis was performed for studies providing radiation exposure or fluoroscopy use per screw placed to determine which navigation modality was associated with the lowest intraoperative radiation exposure. Values on meta-analysis were reported as mean ± standard deviation.

RESULTS

We identified 4956 unique articles, of which 85 met inclusion/exclusion criteria. Forty-one articles were included in the meta-analysis. Patient radiation exposure per screw placed for each modality was: conventional fluoroscopy without navigation (0.26±0.38 mSv), conventional fluoroscopy with pre-operative CT-based navigation (0.027±0.010 mSv), intraoperative CT-based navigation (1.20±0.91 mSv), and robot-assisted instrumentation (0.04±0.30 mSv). Values for fluoroscopy used per screw were: conventional fluoroscopy without navigation (11.1±9.0 seconds), conventional fluoroscopy with navigation (7.20±3.93 s), 3D fluoroscopy (16.2±9.6 s), intraoperative CT-based navigation (19.96±17.09 s), and robot-assistance (20.07±17.22 s). Surgeon dose per screw: conventional fluoroscopy without navigation (6.0±7.9 × 10^-3 mSv), conventional fluoroscopy with navigation (1.8±2.5 × 10^-3 mSv), 3D Fluoroscopy (0.3±1.9 × 10^-3 mSv), intraoperative CT-based navigation (0±0 mSv), and robot-assisted instrumentation (2.0±4.0 × 10^-3 mSv).

CONCLUSION

All image guidance modalities are associated with surgeon radiation exposures well below current safety limits. Intraoperative CT-based (iCT) navigation produces the lowest radiation exposure to surgeon albeit at the cost of increased radiation exposure to the patient relative to conventional fluoroscopy-based methods.