Safety and efficacy of 2D-fluoroscopy-based iliosacral screw osteosynthesis: results of a retrospective monocentric study

Percutaneous Sacroiliac Screw Fixation: A Modified Screw Insertion Method Using Just 2 Fluoroscopy Views

Objectives

Percutaneous sacroiliac screw fixation (PSSF) is a well-defined method of surgery to fix unstable fractures of the pelvic ring with fewer post-surgical complications. However, the complex anatomy of the mentioned area makes PSSF a formidable challenge. The present study aimed to investigate a modified screw insertion method using two views of fluoroscopy X-ray instead of the prior three views to reduce the duration of operations and radiation exposures.

Methods

The present study was performed on 10 radiopaque plastic pelvic models (including 20 half pelvis) during simulated surgical procedures. Of the 20 screws, 10 were inserted using the conventional method with the navigation of three fluoroscopy views (Group A). The remaining 10 were inserted using the modified method with the navigation of two fluoroscopy views, including just the outlet and inlet views, without taking the lateral view, based on our theory and order of fluoroscopy (Group B). Following screw insertion, the accuracy of screw locations was evaluated using a computed tomography (CT) scan, and the duration of operations and radiation exposures were compared between the two surgery methods at the end of the study.

Results

In both groups, nine screws (90%) were located correctly, and one screw (10%) perforated the anterior wall of the first sacral vertebra. The mean±SD of the duration of radiation exposure in groups A and B was 6.1±1.0 min and 4.2±0.1 min, respectively (P=0.01). Moreover, the mean±SD of operation duration in group A was 45.7±5.8 min, but this value in group B was 35.5±4.5, which showed a significant decrease in operation duration (P=0.04).).

Conclusion

PSSF using a modified screw insertion method with just two fluoroscopy views not only had similar accuracy to conventional methods but also could decrease operation time and the following radiation exposure.

The Use of a Robotic Arm for Fixation of Pelvic Fractures

OBJECTIVES

The objective of this study was to evaluate unplanned cortical or neuroforaminal violation of iliosacral and transsacral screw placement using fluoroscopy versus screw placement using a robotic arm.

DESIGN

This is a prospective cohort study.

SETTING

Single surgeon, single North American level 1 trauma center.

PATIENTS

Radiographic and clinical data for 21 consecutive adult trauma patients with pelvic ring fractures undergoing surgical treatment were prospectively collected. Treatment consisted of iliosacral and/or transsacral screws with or without anterior fixation.

INTERVENTION

Ten patients were treated with the assistance of a robotic arm. Eleven patients were treated with standard fluoroscopic techniques.

MAIN OUTCOME MEASUREMENTS

Thirty-two screws were placed and evaluated with postoperative computed tomography or O-arm spins to assess unplanned cortical or neuroforaminal violation. Violations were graded according to the Gertzbein and Robbins system for pedicle screw violation, categorizing screw violation in 2-mm increments. The postoperative images were blindly reviewed by 5 fellowship-trained orthopaedic traumatologists. The treating surgeon was excluded from review.

RESULTS

The Mann-Whitney U test on the Gertzbein and Robbins system results demonstrated significantly (P = 0.02) fewer violations with robotic assistance. χ2 analysis of whether there was a cortical violation of any distance demonstrated significantly (P = 0.003) fewer cortical violations with robotic assistance. There were no neurovascular injuries in either group.

CONCLUSION

Robotic assistance demonstrated significantly fewer unplanned cortical or neuroforaminal violations. Further research is needed with additional surgeons and sites to evaluate the accuracy of iliosacral and transsacral screw placement with robotic assistance.

LEVEL OF EVIDENCE

Therapeutic, level II.

Minimally invasive bilateral fixed angle locking fixation of the dorsal pelvic ring: clinical proof of concept and preliminary treatment results

PURPOSE

Dorsal pelvic ring fractures may result from high energy trauma in younger patients or from osteoporosis as fragility fractures in elderly patients. To date, no strong consensus exists on the best surgical technique to treat posterior pelvic ring injuries. The aim of this study was to evaluate the surgical performance of a new implant for angle-stable fixation of the posterior pelvic ring and patient outcome.

METHODS

In a prospective pilot study, 27 patients (age: 39-87 years) with posterior pelvic ring fractures classified according to the AO classification (n = 5) or to the fragility fractures of the pelvis (FFP) classification (n = 22) were treated using the new implant. During a follow-up period of 1 year, surgical parameters of the implantation technique, complication rate, morbidity, mortality, preservation of patient mobility, and social independence were evaluated.

RESULTS

No implant misplacement or failure was observed. Two patients developed symptomatic spinal canal stenosis at L4/L5 following mobilization. MRI diagnosis proved the implant was not responsible for the symptoms. In one case, an additional plate stabilization of a pubic ramus fracture was necessary 6 months later. There was no inpatient mortality. One patient died due to her underlying oncological disease within the first 3 months. The main outcome parameters were pain, mobility, preservation of independent living and employment.

CONCLUSION

Operative instrumentation of dorsal pelvic ring fractures should be stable enough to allow for immediate weight bearing. The new locking nail implant offers percutaneous reduction and fixation options and may decrease the generally observed rate of complications.

TRAIL REGISTRATION

German Clinical Trials Register ID: DRKS00023797, date of registration: 07.12.2020.

Optimal insertion positions of anterior-posterior orientation sacroiliac screw

PURPOSE

To explore the optimal insertion positions of anterior-posterior orientation sacroiliac screw (AP-SIS).

METHODS

Pelvic CT data of 80 healthy adults were employed to measure the anatomical parameters including the insertable ranges of S1 and S2, the length, width and height of the channel with three different horizontal and vertical anterior insertion points starting from the ilium-acetabular recess. To compare pelvic stability by replicating a type C Tile lesions, fifteen synthetic pelvises were fixed with an anterior plate and a posterior AP-SIS employing different anterior insertion points, the whole specimen displacements and shifts in the sacroiliac gap under a cyclic vertical load of 300 N in a biomechanical machine recorded.

RESULTS

The posterior and anterior insertable ranges averaged 17.9 × 8.5mm² and 47.1 × 21.2 mm², respectively. The channel lengths for three horizontal anterior insertion points gradually decreased from front to back with significant difference (p < 0.05), whereas the width and height for three horizontal anterior insertion points and the parameters for the three vertical anterior insertion points were similar (p > 0.05). The displacements and shifts for three horizontal insertion points gradually increased from front to back (p < 0.05) whereas the measurements involving the three vertical insertion points were similar (p > 0.05).

CONCLUSION

The posterior insertable range is small, where the center between adjacent nerve roots (foramens) is the optimal posterior insertion point. The anterior insertable range is large, where the iliac-acetabular recess is the optimal anterior insertion point for S1 and S2, providing the longest channel and best stability.

Safe Corridor for Sacroiliac Screw Insertion Can Be Found Quickly Without the Use of the Lateral Sacral View

Background

Studies have proved that in addition to the inlet and outlet views, the intraoperative lateral sacral view is required to ensure the correct entry point, reduce operating time, and lower radiation exposure. Considering the complex anatomy of the sacrum, we showed a safe corridor for sacroiliac joint (SIJ) screw insertion that was accessible using only inlet and outlet fluoroscopic views.

Methods

From 2013 to 2020, we enrolled 215 patients who underwent percutaneous SIJ screw insertion. Our experience in SIJ screw insertion is presented using only two views (inlet and outlet). We reported on the radiation exposure time, operating time, rate of screw malposition, neurologic injury, and revision surgery.

Results

The screw malposition rate was 5.5%, including 11 foraminal perforations and one perforated anterior sacral cortex. Paresthesia after the surgery was observed in six patients (2.8%). No revision surgery or screw removal was performed. The radiation exposure and operation time for each screw were 21 ± 4.5 s and 13.5 min, respectively.

Conclusion

The most anterior and the lowest part of the S1 vertebra can be easily found using intraoperative inlet and outlet views. It is a safe corridor for SIJ screw insertion with low radiation time, neurologic injury, and revision rates.

Comparison of fluoroscopy and fluoroscopy-based 2D computer navigation for iliosacral screw placement: a retrospective study

PURPOSE

Treatment of pelvic fractures is often complicated. Here, we intended to evaluate the intraoperative benefits of using 2D computer navigation when compared with traditional fluoroscopy on X-ray burden, surgical time and screw placement accuracy.

METHODS

In this study, we retrospectively evaluated the records of 25 patients who underwent osteosynthesis of a posterior pelvic fracture using fluoroscopy at the University Hospital Ostrava, Czech Republic between 2011 and 2019, and 32 patients from the same department and period in whom 2D computer navigation was used.

RESULTS

Intraoperative X-ray burden was significantly lower in the group with 2D computer navigation (median 650 vs 1024 cGy/cm²), as was the duration of the surgery (41 vs 45 min). This was most obvious where two screws were inserted (X-ray dose of 994 vs 1847 cGy/cm² and 48 vs 70 min, respectively). Correction of the path for wire placement after the original drilling was necessary in 2 patients (6%) from the 2D computer navigation group and 15 patients from the fluoroscopy group (60%). Still, no malposition of the screws nor dislocation of the posterior pelvic segment after 12 months was observed in any patient of either group; of complications, only three superficial infections in the 2D navigation group and 2 in the fluoroscopy group were observed.

CONCLUSION

2D computer navigation is a safe and accurate method for placement of screws during posterior pelvic fracture osteosynthesis, associated with lower intraoperative radiation burden and shorter surgical times compared to standard fluoroscopy, especially if two screws are inserted.

[Sacral fractures in geriatric patients]

Sacral fractures in geriatric patients are increasing and form a distinct entity. Clinical findings can be unspecific, which is why they are easily overlooked. It is mandatory to analyze the whole pelvic ring for evaluation of pelvic stability and for making treatment decisions. The primary diagnostics are made using plain X‑radiography; however, for assessment of the posterior pelvic ring an examination using sectional imaging is regularly necessary. The fragility fractures of the pelvis (FFP) classification is suitable as a guideline for the surgical treatment to be used. Stable fractures without relevant displacement after initial mobilization should be treated conservatively. Instability, failure of mobilization and persistent pain are, however, common reasons for surgical treatment. Fracture displacement determines if minimally invasive procedures for posterior and anterior pelvic ring stabilization are possible. Otherwise, complex open procedures such as spinopelvic fixation may be necessary.

[Minimally invasive stabilization of fragility fractures of the pelvis with transsacral bar and retrograde transpubic screw]

OBJECTIVE

Stabilization of fragility fractures of the pelvis (FFP) using a minimally invasive technique. Insertion of a transsacral rod into the transsacral corridor of S1. Insertion of a retrograde transpubic screw through the superior branch of the pubic bone.

INDICATIONS

Uni- or bilateral displaced fragility fractures of the sacrum or sacroiliac joint. Nondisplaced fractures of the sacrum or sacroiliac joint in case of nonsuccessful conservative treatment. Uni- or bilateral fractures of the superior branch of the pubic bone, which are present in combination with a posterior pelvic instability.

CONTRAINDICATIONS

Fragility fractures of the pelvis, which can be successfully treated conservatively. Absence of transsacral corridor in sacral body S1. Major displacement, nonreducible fractures of the superior branch of the pubic bone. Soft tissue infection at insertion site of implants.

SURGICAL TECHNIQUE

The transsacral bar is inserted under fluoroscopic control from ilium to ilium through the transsacral corridor of the sacral body S1. The retrograde transpubic screw is inserted from the pubic tubercle through the superior branch of the pubic bone past the acetabulum into the body of the ilium.

POSTOPERATIVE MANAGEMENT

An early mobilization with weight bearing of both lower extremities as tolerated by the patient is allowed. Conventional radiographs for control of the position of the implants and fractures are taken after mobilization RESULTS: In all, 64 patients with FFP type II, FFP type III or FFP type IV were stabilized with a transacral bar osteosynthesis in the posterior pelvis. In 32 patients (50%), additional sacroiliac screws were inserted. In 29 patients (45.3%) the transsacral bar osteosynthesis was combined with a transpubic retrograde screw. Median length of hospital stay was 17.5 days. In all, 20 patients (31.3%) suffered general, 10 patients (15.6%) suffered surgery-related complications, and 41 patients (64.1%) were mobile in the room or on the ward at discharge. One-year mortality was 10.9%. The values of the SF‑8 Physical and Mental Component Scores, Parker Mobility Score and Numeric Rating Scale were moderate, yet comparable with the values of patients of the same age.

Preoperative CT simulation of iliosacral screws for treating unstable posterior pelvic ring injury

BACKGROUND

The percutaneous iliosacral screw is a common procedure for treating pelvic posterior ring instability. Traditional X-ray fluoroscopy screw placement has the advantages of decreased bleeding and trauma, but it also has some drawbacks, such as increased radiation exposure and screw dislocation. The purpose of this study was to establish a safe, effective, and quick approach for putting iliosacral screws for the treatment of unstable posterior pelvic ring damage utilizing simulated screws based on preoperative computed tomography (CT) planning.

METHODS

From February 2019 to June 2020, we retrospectively assessed 41 patients with posterior pelvic ring instability who were treated with percutaneous iliosacral screws in our institution, and randomly separated them into two groups: conventional surgery (n = 20) and preoperative planning (n = 21). Pelvic radiographs (anteroposterior, inlet, outlet), as well as normal CT scans of the pelvis, were all taken postoperatively to confirm the screw position. After that, the screw insertion time, the radiation exposure time, and the screw misplacement rate (as assessed by postoperative CT) were all examined. Screw position grading was evaluated by Smith grading.

RESULTS

In the conventional surgery group, 26 screws were inserted in 20 patients, with each screw insertion taking 23.15 ± 4.19 min and 1.02 ± 0.17 min to expose to radiation. Eight of the 26 screws were misplaced (30.8%). In the preoperative planning group, 24 screws were inserted in 21 patients, with each screw taking 19.57 ± 4.05 min to implant and 0.67 ± 0.09 min to expose to radiation. One of 24 screws was misplaced (4.2%). Screw insertion time, radiation exposure time, and screw dislocation rate were all significantly reduced when preoperative planning aided iliosacral screw placement (P < 0.05).

CONCLUSIONS

Preoperative CT simulation of iliosacral screws for placement planning, screw trajectory, and intraoperative screw placement is a safe way for reducing surgical time, radiation exposure, and ensuring accurate screw placement.

Differences in Accuracy and Radiation Dose in Placement of Iliosacral Screws: Comparison between 3D and 2D Fluoroscopy

Percutaneous iliosacral screw fixation is a widely accepted method of stabilizing the posterior pelvic ring. Recently developed tools such as 3D-navigated fluoroscopy and computed navigation seem to prevent a surgeon from conducting screw misplacement. The study aimed to comparatively assess the introduction of sacroiliac screw placement using 2D and 3D fluoroscopy in terms of accuracy and radiation exposure. Iliosacral screws were introduced in 37 patients using 2D (group N1) and in 36 patients using 3D fluoroscopy (group N2) techniques. Overall, 61 and 56 screws were introduced in groups N1 and N2, respectively. Screw placement accuracy was assessed using postoperative computed tomography and Smith’s scale. Intraoperative radiation exposure was also assessed. No differences were noted between groups in terms of screw positioning accuracy and radiation dose. Both 2D and 3D fluoroscopy provide good visualization for safely placing percutaneous iliosacral joint screws. Using 3D fluoroscopy-based navigation in comparison with 2D fluoroscopy is not advantageous.

Artificial intelligence and CT-based 3D statistical modeling to assess transsacral corridors and plan implant positioning

Transsacral corridors at levels S1 and S2 represent complex osseous spaces allowing percutaneous fixation of non- or minimally-displaced fragility fractures of the sacrum. To safely place transsacral implants, they must be completely intraosseous. However, standard radiographs and CT do not properly demonstrate the corridor's intricate configuration. Our goal was to facilitate the three-dimensional assessment of transsacral corridors using artificial intelligence and the planning of transsacral implant positioning. In total, 100 pelvic CTs (49 women, mean age: 58.6 ± SD 14.8 years; 51 men, mean age: 60.7 ± SD 13 years) were used to compute a 3D statistical model of the pelvic ring. On the basis of morphologic features (=predictors) and principal components scores (=response), regression learners were interactively trained, validated, and tuned to predict/sample personalized 3D pelvic models. They were matched via thin-plate spline transformation to a series of 20 pelvic CTs with fragility fractures of the sacrum (18 women and 2 men, age: 69-9.5 years, mean age: 78.65 ± SD 8.4 years). These models demonstrated the availability, dimension, cross-section, and symmetry of transsacral corridors S1 and S2, as well as the planned implant position, dimension, axes, and entry and exit points. The complete intraosseous pathway was controlled in CT reconstructions. We succeeded to establish a workflow determining transsacral corridors S1 and S2 using artificial intelligence and 3D statistical modeling.

Trans-sacral bar osteosynthesis provides low mortality and high mobility in patients with fragility fractures of the pelvis

Operative treatment of osteoporosis-associated fragility fractures of the pelvis (FFP) and the sacrum is advocated with immobilizing or longstanding pain, fracture progression and displacement. We analyzed clinical outcomes regarding mobility, quality of life, and mortality of patients with FFP treated with trans-sacral bar (TB) osteosynthesis through S1. Demographics, clinical data, and operation-related data of patients with an FFP treated with TB were acquired from chart review. We assessed mortality, quality of life (EQ-5D), mobility, and residential status at follow-up. Seventy-nine females and six males with a median age of 78.0 years (IQR 73–84) were included, median follow-up was 3.2 years. Medical complications during hospitalization occurred in 28%. Operative revision was carried out in 15% of patients. One-year survival was 90.4%, this was associated with shorter preoperative and total length of stay in hospital (p 0.006 and 0.025, respectively). At follow-up, 85% lived at home and 82% walked with or without walking aid. Higher EQ-5D was reached with higher mobility status and living at home (p < 0.001 and < 0.001, respectively). TB osteosynthesis is an adequate and reliable method for fixation of FFP in the posterior pelvic ring to ensure timely mobilization. Shorter preoperative and total length of stay had lower mortality rates, advocating a standardized management protocol to limit time delay to operative therapy. Patients treated with TB osteosynthesis had low 1-year mortality of less than 10%.

Secondary Angio-Embolization After Emergent Pelvic Stabilization and Pelvic Packing Is a Safe Option for Patients With Persistent Hemorrhage From Unstable Pelvic Ring Injuries

Introduction: In patients with severe pelvic ring injuries, exsanguination still is the leading cause of death in the early post-injury phase. While mechanical pelvic ring stabilization and pre-peritoneal pelvic packing are mainly addressing venous bleeding, angio-embolization aims to control arterial bleeding. The goal of the present study was to evaluate the rate of postoperative angio-embolization after mechanical pelvic ring injury stabilization and pre-peritoneal pelvic packing. Bleeding sources detected in the angiography and the patient's outcome were investigated.

Patients and Methods: Retrospective observational cohort study at a single academic level I trauma center, reviewing all patients with pelvic ring injuries admitted from 01/2010 to 12/2019. Patients with emergent mechanical pelvic ring stabilization (supraacetabular external fixator and/or pelvic C-clamp) and direct pre-peritoneal pelvic packing were further analyzed. Patients that underwent postoperative angio-embolization were compared with those that did not. All postoperative angio-embolizations were evaluated with regards to bleeding sources and type of embolization.

Results: During the study period, a total of 39 patients required immediate mechanical pelvic stabilization and direct pre-peritoneal pelvic packing. Of these, 12 patients (30.8%) underwent a postoperative angio-embolization. The following vessels were identified as bleeding sources: superior gluteal artery (n = 6), obturator artery (n = 2), internal pudendal artery (n = 2), unnamed branches of the internal iliac artery (n = 3). A selective embolization was successful in 11 patients; in 1 patient, an unilateral complete occlusion of the internal iliac artery was performed to control the bleeding. Mean time from hospital admission to the surgical procedure was 52.8 ± 14.7 min and the mean time from admission to angio-embolization was 189.1 ± 55.5 min. The in-hospital mortality rate of patients with angio-embolization was 25.0% (n = 3). Of these, 2 patients died due to multiple organ failure and 1 patient due to severe head injury.

Conclusion: Secondary angio-embolization after external pelvic fixation and pre-peritoneal pelvic packing was effective in controlling ongoing bleeding. The most frequently detected bleeding vessel was the superior gluteal artery, which is difficult to surgically address, further highlighting the importance of angio-embolization in the management algorithm.