Iliosacral Screw Research Articles

Anatomical Study of a Novel Iliosacral Screw Placement for Sacrum-Pelvis in Adult Via Computed Tomography Reconstruction.

This is a cross-sectional study. To investigate the feasibility and safety of a novel iliosacral screw placement for sacrum-pelvis in adult pelvis by computed tomography (CT) reconstruction. The optimal technique of spino-pelvic fixation is still being developed and redefined. However, neither the relevant anatomic parameters nor the potential spinal canal involvement for a novel iliosacral screw placement have been clearly analyzed. A total of 60 adults with normal pelvis, with the age ranging from 24 to 79 years old, were included in this study. Based on three-dimensional (3D) CT reconstruction of each pelvis, virtual iliosacral screw channel was identified bilaterally, the trajectory of which was characterized with the optimal width and length from the ilium to the sacrum. The virtual iliosacral screw channel that holding the greatest width and length of osseous channel was measured by rotating the 3D pelvis. Measurements of the determined channel on either side included iliosacral-screw-related and connector-related parameters. There was a virtual iliosacral screw channel passing through the ilium, the iliosacral joint and then into the sacrum on either side of each pelvis. The caudal angle, convergent angle, and maximal length were 16.3 ± 3.0°, 61.3 ± 5.9°, 97.0 ± 5.6 mm in male, respectively. In female, they were 16.4 ± 3.9°, 63.0 ± 5.5° and 96.2 ± 6.0 mm, respectively. The ideal direction of the connector was from posteromedial to anterolateral. The cephalad angle, divergent angle, and embedding depth of the connector were 28.0 ± 5.7°, 28.7 ± 5.9° and 19.0 ± 2.9 mm in male, respectively. In female, they were 26.7 ± 6.1°, 27.0 ± 5.5° and 16.4 ± 2.6 mm, respectively. It is safe and feasible to place the iliosacral screw when performing this novel instrumentation. Preoperative CT imaging and 3D reconstructions may help to determine the correct entry point and the trajectory of iliosacral screw. 5.

Minimally invasive, robot-assisted iliosacral screw insertion for fusionless fixation in children with neuromuscular scoliosis.

Fusionless surgery coupled with growing rod techniques is increasingly advocated for the treatment of early-onset scoliosis in general and neuromuscular scoliosis in particular. Iliosacral screws have excellent biomechanical characteristics but are hard to place safely. Here, the authors report on robot-assisted iliosacral screw positioning as part of growing rod surgery for the fusionless correction of early-onset scoliosis. The technique is based on a bilateral double sliding rod construct anchored to the pelvis proximally with 6 hooks or sublaminar bands and distally with iliosacral screws placed by the robot. The video can be found here: https://youtu.be/5HGH_DiD-ck .

Biomechanical study of three kinds of internal fixation for the treatment of sacroiliac joint disruption using biomechanical test and finite element analysis

BackgroundTo compare the stability of sacroiliac joint disruption fixed with three kinds of internal fixation using both biomechanical test and finite element analysis.MethodsFive embalmed specimens of an adult were used. The symphysis pubis rupture and left sacroiliac joint disruption were created. The symphysis pubis was stabilized with a five-hole plate. The sacroiliac joint disruption was fixed with three kinds of internal fixation in a randomized design. Displacements of the whole specimen and shifts in the gap were recorded. Three-dimensional finite element models of the pelvis, the pelvis with symphysis pubis rupture and left sacroiliac joint disruption, and three kinds of internal fixation techniques were created and analyzed.ResultsUnder the vertical load, the displacements and shifts in the gap of the pelvis fixed with minimally invasive adjustable plate (MIAP) combined with one iliosacral (IS) screw were the smallest, and the average displacements of the pelvis fixed with an anterior plate were the largest one. The differences among them were significant. In finite element analysis and MIAP combined with one IS screw fixation showed relatively best fixation stability and lowest risks of implant failure than two IS screws fixation and anterior plate fixation.ConclusionThe stability of sacroiliac joint disruption fixed with MIAP combined with one IS screw is better than that fixed with two IS screws and anterior plate under vertical load.

Sacroiliac luxation in small animals: treatment options

The term sacroiliac luxation-fracture (SIL/F) denotes traumatic separation of the ilial wing from the sacrum. This injury typically results from a traumatic event (most commonly a road traffic accident) and consequently is often seen with concomitant pelvic and/or other orthopaedic injuries. When indicated, the method of choice for SIL/F repair is lag screw fixation, which can be achieved via open reduction and internal fixation or minimally invasive osteosynthesis. The prognosis is in part affected by proper orientation of the iliosacral screw and adequate screw purchase into the sacral body. While conservative management may yield good outcomes, pain associated with nerve damage as well as chronic instability of the SIL, along with concomitant orthopedic and soft tissue injuries, should be thoroughly considered when choosing this option.

Surgical management of U/H type sacral fractures: outcomes following iliosacral and lumbopelvic fixation.

U and H-type sacral fractures are under diagnosed injuries resulting from significant axial loading that are often associated with neurological deficits. No studies to date have compared two common methods of surgical fixation, iliosacral screw fixation (ISF) and lumbopelvic fixation (LPF). Patients with sacral fractures from 2009-2015 at one level 1 trauma center were identified by current procedural terminology (CPT) code and imaging reviewed for U/H type sacral fractures. Four hundred and fifty-three sacral fractures were identified during the study period, of which sixteen patients met inclusion criteria for the study. Six patients had the presence of a documented neurological injury at the time of presentation, 9 patients had concurrent spine fractures and 10 patients had concurrent pelvic fractures. Eight patients underwent ISF and 8 patients underwent LPF. There was no significant difference between the two groups in regards to age, intensive care unit (ICU) requirement, length of stay, or estimated blood loss. There was a significant increase in surgical time in the LPF group (P=0.002). In addition, there was a significant difference between those patients that underwent ISF that were discharged to a rehab facility compared to those treated with LPF (P=0.04). Patients with U/H type sacral fractures can be treated with ISF or LPF without an expected increase in hospital length of stay (LOS) or need for ICU. Treatment with LPF may increase operative time however; the patient is more likely to be discharged to home instead of a rehab facility.

Successful Use of Fluoroscopic Inlet and Outlet Views to Verify Safe Screw Trajectories when Placing Percutaneous Iliosacral Screws

Successful Use of Fluoroscopic Inlet and Outlet Views to Verify Safe Screw Trajectories when Placing Percutaneous Iliosacral Screws

Sacral Fractures with Spondylopelvic Dissociation.

* U-type or H-type sacral fractures are a result of very high energy injuries that separate the lumbar spine and upper sacrum from the lower sacrum and pelvis. Advances in acute trauma care have resulted in an increase in the number of patients who survive this injury.* The choice of approach is dictated by several factors, including dorsal soft-tissue trauma, the need for neurological decompression, and the adequacy of sacral sagittal balance.* Complication rates following surgical treatment are high and primarily are related to the soft tissues.* This fracture pattern has a high association with polytrauma, major neurological injury (including cauda equina syndrome), and soft-tissue degloving injuries.* While nonoperative management may be appropriate for patients who are expected to be bedbound or non-weight-bearing for at least 3 months, the majority of these injuries are treated surgically with iliosacral screws and spinal constructs that anchor the pelvis to the lower lumbar spine.* Careful attention to damage-control principles, efficient surgical stabilization of the spondylopelvic injury and associated fractures, and early mobilization can lead to good functional outcomes following this potentially devastating injury.

Biplanar Posterior Pelvic Fixator for Unstable Sacral Fractures: A New Fixation Technique.

Fixation of comminuted vertically unstable sacral fractures continues to be a surgical dilemma. Although triangular osteosynthesis is a good construct and resists vertical translation, complications still occur. Herein, we introduce a new biplanar fixation technique, using segmental spinal instrumentation as an alternative to triangular osteosynthesis. This technique is remarkably valuable in cases with sacral morphology and/or complex fracture patterns that preclude safe percutaneous iliosacral screw insertion.

Fragility fractures of the sacrum occur in elderly patients with severe loss of sacral bone mass.

Patients suffering from osteoporosis-associated fragility fractures of the sacrum (FFS; also termed sacral insufficiency fractures) are increasingly observed. They have typical fracture patterns with fracture lines located in the sacral ala. When treating these patients operatively, iliosacral screw loosening is not uncommon. We aimed to study the sacral bone mass in patients presenting with a FFS using 3D statistical models. 3D models of averaged Hounsfield units (HU) were generated based on CT scans from 13 patients with a unilateral FFS (mean age 79.6 years; 11 females, 2 males). The control group without fractures consisted of 28 males and 32 females (mean age of 68.3years). A virtual bone probe along the trans-sacral corridors S1 and S2 was taken. The bone mass distribution in the fractured sacra was similar to the control group, however, with overall lower HU. Large zones of negative HU were located in the sacral ala. In the fractured sacra, the HU in the sacral ala was significantly lower on the non-injured side when comparing to the fractured side (p < 0.001) as well as compared to the non-fractured group (p < 0.001). Low bone mass was observed in sacral body S1 (40 HU) and S2 (20 HU). The extensive area of negative HU may explain the fracture location in the sacral ala. The low HU in the sacral bodies advocates the use of trans-sacral implants or augmented iliosacral screws to enhance the strength of fracture fixation. The increased HU in the fractured ala could be explained by fracture-asssociated hemorrhage and can be used as a diagnostic tool.

"Baloon guided" augumentace iliosakrálních šroubů kostním cementem v léčení insuficientních zlomenin sakra - popis nové metody a předběžné výsledky

"Baloon guided" augumentace iliosakrálních šroubů kostním cementem v léčení insuficientních zlomenin sakra - popis nové metody a předběžné výsledky

Euthyphoria reduction combined with percutaneous iliosacral screw fixation for irreducible sacroiliac dislocation

Objective To evaluate euthyphoria reduction combined with percutaneous iliosacral screw fixation in the treatment of irreducible sacroiliac dislocation. Methods From March 2012 to May 2015, 29 patients with irreducible sacroiliac dislocation were treated using euthyphoria reduction followed by percutaneous iliosacral screw fixation. They were 18 men and 11 women, aged from 25 to 68 years (average, 37.9 years). According to the Tile classification, there were 7 cases of type C1, 9 cases of type C2, and 13 cases of type C3. The intervals from injury to surgery ranged from 6 to 32 days (average, 11.3 days). Results The operation time for this cohort ranged from 40 to 125 minutes (average, 76.2 minutes). The intraoperative bleeding ranged from 50 to 360 mL (average, 148.6 mL). Their follow-ups ranged from 24 to 41 months (average, 28.9 months). According to the Matta criteria for reduction, 20 cases were rated as excellent and 9 as good, yielding an excellent to good rate of 100%. Their Majeed scores at the final follow-up averaged 90.1 points (range, from 67 to 100 points), giving 20 excellent, 7 good and 2 fair cases (with an excellent to good rate of 93.1%). No screw loosening or lameness of the affected limb was observed during follow-ups. Conclusions Euthyphoria reduction combined with percutaneous iliosacral screw fixation can lead to satisfactory outcomes in the treatment of irreducible sacroiliac dislocation. Additionally it may improve operative safety. Key words: Pelvis; Fractures, bone; Fracture fixation, internal; Bone nails; Reduction

Value of pelvic CT sagittal reconstruction for percutaneous insertion of iliosacral screws

Objective To investigate the value of pelvic CT sagittal reconstruction for percutaneous insertion of iliosacral screws. Methods Data of 32 patients who had been treated for pelvic posterior ring injury from June 2015 to March 2017 were retrospectively analyzed. There were 21 males and 7 females, aged from 21 to 75 years (average, 43.2 years). According to Tile classification for pelvic fractures, there were 23 cases of type B (type B1 in 4, type B2 in 13 and type B3 in 6), and 9 cases type C (type C1 in 6, type C2 in 2 and type C3 in 1). The pelvic CT three-dimensional reconstruction was performed before operation, and the reconstructed layer of CT sagittal position was overlapped, and preset S1, S2 sacroiliac joint hollow. Insert the screws according to the preset needle point and passage under the perspective of C-arm X-ray machine during the operation. In 32 cases of patients, 3 cases of type C1, 1 case of type C2 and 1 case of type C3 fractures in sacroiliac joint hollow combined with S1-ilium pedicle screw internal fixation, and the rest of 27 patients were treated by iliosacral screws. The time for each screw placement and the times of X-ray projection were recorded. The position of cannulated screw was observed by CT scan and compared with the preset channel after the operation. Postoperative reduction quality was assessed using Matta radiological criteria and Majeed criteria was used at the final follow-ups to evaluate the pelvic function. Results The operations time was ranged from 40 to 240 min (average, 130 min); and the blood loss was ranged from 20 to 150 ml (average, 80 ml). Altogether 58 iliosacral screws were inserted in 32 patients. The time for each screw placement was ranged from 5 to 15 min (average, 9.5 min); and the number for each screw X-ray projection was ranged from 7 to 15 times (average, 10.2 times). Postoperative CT scan and vascular ultrasound showed that all the iliosacral screws did not penetrate the cortical bone or damaged the vascular nerves, and the error of the preset channel was from 0 to 5 mm (average, 2.2 mm). All fractures healed successfully, and the healing time was 12 to 18 weeks (average, 14.2 weeks). According to Matta radiological criteria, reduction was excellent in 26, good in 3 and fair in 3, with an excellent to good rate of 90.6% (29/32). The follow-up time for the 32 patients was ranged from 6 to 15 months (average, 11.3 months). At the latest follow-ups, X-ray and CT examination showed fine fracture union and no loosening or breakage of screws in all. By the Majeed criteria, the pelvic function was excellent in 21 cases, good in 8 cases, fair in 3 cases, with a good to excellent rate of 90.6% (29/32). Conclusion Preoperative pelvic CT sagittal reconstruction for preset of iliosacral screw insertion point, angle and length can achieve more accurate placement, shorter operative time and less time of X-ray projections. Key words: Tomography, X-ray computed; Pelvis; Sacroiliac joint

Treatment of unstable pelvic fractures by cannulated screw internal fixation with the assistance of three-dimensional printing insertion template

To evaluate the effectiveness of unstable pelvic fractures treated by cannulated screw internal fixation with the assistance of three-dimensional (3D) printing insertion template. The clinical data of 10 patients who underwent surgical treatment for unstable pelvic fractures by cannulated screw internal fixation with the assistance of 3D printing insertion template between May 2015 and June 2016 were retrospectively analysed. There were 7 males and 3 females with an average age of 37.5 years (range, 20-58 years). The causes of injury included falling from height in 5 cases, crushing from heavy load in 1 case, and traffic accidents in 4 cases. The interval from injury to admission was 1-5 hours (mean, 3.1 hours). The fracture situation included 6 cases of sacral fracture, 1 case of right sacroiliac joint dislocation, and 3 cases of iliac bone fracture. There were 10 cases of superior and inferior pubic rami fracture, including 3 cases on the left side (2 cases of suprapubic fracture adjacent to symphysis pubis), 2 cases on the right side, and 5 cases on the bilateral. All fractures were classified according to the Tile system, there were 4 cases of type B2, 1 of type B3, 4 of type C1, and 1 of type C2. The radiological outcome was evaluated by Matta scale, and the positions of the iliosacral screw and superior pubic ramus screw were evaluated according to 3D reconstruction of CT postoperatively. The functional outcome was evaluated by Majeed function scale. The average time of each screw implantation was 30 minutes, and the average blood loss per screw incision was 50 mL. The time of implantation of each sacroiliac screw was 24-96 seconds (mean, 62 seconds), and the time of implantation of each suprapubic screw was 42-80 seconds (mean, 63.2 seconds). The hospitalization duration was 17-90 days (mean, 43.7 days). All incisions healed by first intention. All patients were followed up 12-22 months (mean, 15.6 months). The radiological outcome was excellent in 8 cases and good in 2 cases according to Matta scale; and 3D reconstruction of CT demonstrated that all the 9 iliosacral screws were placed as type Ⅰ, and all the 13 suprapubic ramus screws were placed as grade 0 on the first postoperative day. No complication such as neurovascular injury, screw back out or rupture, or secondary fracture displacement was observed during the follow-up. At 6 months after operation, the X-ray films showed good fracture healing in all the 10 patients. The functional outcome was excellent in 9 cases and good in 1 case according to Majeed scale at 1 year after operation. One patient sustained Tile C2 pelvic disruption complicated with L 5 nerve root injury achieved complete nervous functional recovery at last follow-up. It has advantages of precise screw insertion and lower risk of neurovascular injury to treat unstable pelvic fractures by cannulated screw internal fixation with the assistance of 3D printing insertion template, which can be a good alternative for the treatment of unstable pelvic fractures.

A New Modified Method for Inserting Iliosacral Screw versus the Conventional Method.

Study DesignMethodological study.PurposeTo our knowledge, this is the first study to introduce a new modified method for inserting iliosacral screws and to compare its results with those of a conventional method.Overview of LiteraturePrevious techniques, such as open reduction and internal fixation, are associated with perioperative hemorrhage, postoperative infection, and neurological deficits. Although percutaneous iliosacral screw insertion confers the advantage of being minimally invasive, leading to less blood loss and a low postoperative infection rate, it harbors the risk of screw malpositioning due to narrow sacral proportions and a high interindividual variability.MethodsNine cadaveric pelvises were included in this study, with one hemipelvis of each being assigned to the new modified method and the other to the conventional iliosacral screw insertion method. In the new modified method, the guidewire entry point was determined using a lateral sacral X-ray. To do so, we first identified the anterosuperior quadrant of the S1 body on one hemipelvis. The anterosuperior quadrant was further divided into four imaginary quadrants, and the guidewire was inserted into the posteroinferior quadrant. The guidewire trajectory was perpendicular to the sagittal plane so that the guidewire resembled a single point in the lateral sacral view. Guidewires were inserted into corresponding hemipelves using the conventional method as described in the literature. Subsequently, an axial computed tomography scan with 1-mm fine cuts was obtained, and sagittal and coronal views were reconstructed. The distance of the guidewire from the sacral canal, anterior sacral cortex, and first sacral foramen was measured in axial, sagittal, and coronal views. The minimum measurement among different views was defined as the safety index of the insertion methods. The conventional and new modified methods were then compared in terms of safety and duration of the procedure.ResultsThe minimum distance of the guidewire from the S1 foramen and anterior sacral cortex was not significantly different between the two methods. However, the minimum distance between the guidewire and sacral canal was significantly greater in the new modified method than in the conventional method. The duration of guidewire insertion was significantly shorter in the new modified method than in the conventional method.ConclusionsThis new modified method of iliosacral screw insertion could be safely and simply implemented while taking less surgical time than the conventional methods.

Minimally Invasive Surgery for Neuromuscular Scoliosis: Results and Complications in a Series of One Hundred Patients.

Study Design.A retrospective review.Objective.To report the results of an alternative technique using a minimally invasive fusionless surgery. The originality is based on the progressive correction of the deformities with proximal and distal fixation and on the reliability of the pelvic fixation using iliosacral screws on osteoporotic bones.Summary of Background Data.Spinal deformities are common in neuromuscular diseases. Conventional treatment involves bracing, followed by spinal instrumented fusion. Growing rod techniques are increasingly advocated but have a high rate of complications.Methods.The technique relies on a bilateral double rod sliding construct anchored proximally by four hooks claws and distally to the pelvis by iliosacral screws through a minimally invasive approach. Hundred patients with neuromuscular scoliosis underwent the same fusionless surgery extended from T1 to the pelvis. The average age at initial surgery was 11 + 6 years. Diagnoses included cerebral palsy (61), spinal muscular atrophy (22), muscular dystrophy (10), and other neurological etiologies (7). Cobb angle and pelvic obliquity were measured before and after initial surgery, and at final follow-up. Complications were reviewed.Results.At latest follow-up 3 + 9 years (range 2 yr–6 + 3 yr), the mean Cobb angle improved from 89° to 35° which corresponds to 61% correction. Mean pelvic obliquity improved from 29° to 5°, which corresponds to 83% correction. Mean T1-S1 length increased from 30.02 to 37.28 cm. Mean preoperative hyper kyphosis was reduced from 68.44° to 33.29°. Complications occurred in 26 patients including mechanical complications (12) and wound infections (16). No arthrodesis was required at last follow-up.Conclusion.This original fusionless technique is safe and effective, preserving spinal and thoracic growth. It provides a significant correction of spinal deformities and pelvic obliquity with a reduced complications rate. The strength and stability of this modular construct over time allow the avoidance of final arthrodesis.Level of Evidence: 4

Does Posterior Fixation of Partially Unstable Open-Book Pelvic Ring Injuries Decrease Symphyseal Plate Failure? A Biomechanical Study.

Recent clinical study suggests an advantage to adding an iliosacral screw to the anterior fixation construct for anteroposterior compression type-2 (OTA/AO type 61-B1), partially unstable open-book pelvic ring injuries. Others have described stress examination to determine any required supplemental fixation. However, biomechanical studies investigating iliosacral fixation requirements for this injury are lacking. Our objective was to determine whether adding an iliosacral screw to symphyseal plate fixation decreases displacement in a well-defined open-book pelvic ring injury model. An open-book pelvic ring injury was created in 10 human cadaveric pelves by unilaterally releasing the sacrospinous, sacrotuberous, and anterior sacroiliac ligaments plus transection of the pubic symphysis, approximating the classically described anteroposterior compression type-2 (APC-2) injury. Specimens were divided into 2 groups: (1) symphyseal plating and (2) plating plus an iliosacral screw. Using a standard bilateral stance model loaded at 550 N, displacement measurements were obtained at 210,000 and 500,000 cycles. Three specimens failed before 210,000 cycles because of technical errors and were excluded from analysis. For the remaining 7, there was no significant difference in displacement between the 2 groups, and none sustained implant failure. Post hoc analysis showed that a large sample size (45/group) would be required to detect any difference with 80% power, indicating a small effect size with limited clinical application. Adding an iliosacral screw to the symphyseal plate fixation does not provide improved biomechanical outcome in classically described APC-2 injuries. Clinically, stress examination may be useful to determine the need for supplemental posterior fixation in APC-2 injuries.

Safe corridor for iliosacral and trans-sacral screw placement in Indian population: A preliminary CT based anatomical study

ObjectivesNonsurgical management of unstable pelvic ring injuries is associated with poor outcomes. Posterior pelvic ring injuries include sacroiliac joint disruption and sacral fractures or a combination of the two. Morbidity is high in non-operatively managed patients. Screw fixation is being increasingly used to manage unstable posterior pelvic injuries. Limitations include a steep learning curve and potential for neurovascular injury. This is the first study in Indian population to describe the safe corridor for screw placement and check the feasibility of screw in both upper and lower sacral segments. MethodsThis study involved retrospective analysis of 105 pelvic CT scans of patients admitted to the emergency department of a Level 1 trauma centre. Vertical height at the level of constriction (vestibule) of S1 and S2 was measured in coronal sections and anteroposterior width of constrictions was measured in axial sections. We created a trajectory for 7.3 mm cylinder keeping additional 2 mm free bony corridor around it and confirmed that bony limits were not breached in axial, coronal and sagittal sections. Whenever there was breach in bony limit we checked applicability of 6.5 mm screw. ResultsThe vertical height and anteroposterior width of vestibule/constriction of S1 was significantly higher in males, whereas S2 vestibule height and width were similar in males and females. Both male and female pelves were amenable to S1 Trans-sacral and S1 Iliosacral screw fixation with a 7.3 mm screw when a safe corridor of 2 mm was kept on all sides. However, when S2 segment was analysed, only 42.9% of male pelves and 25.7% of female pelves were amenable to insertion of trans-sacral 7.3 mm screw. ConclusionAn individualized approach is necessary and each patient’s CT must be carefully studied before embarking on sacroiliac screw fixation in Indian population.

Ten Tips to Improve Iliosacral Screw Placement

Sacroiliac screw fixation has become the most common procedure for iliosacral joint fracture-dislocations and sacral fractures in the last decade. At present, the standard technique is the percutaneous iliosacral screw fixation under conventional C-arm fluoroscopy. This technique is considered to be a highly demanding operative technique with a high rate of screw malpositions, which may be associated with the risk of neurologic damage or inefficient stability. The surgical steps have been carefully described but, according to our experience, several tricks may be added to those descriptions. The purpose of this review is to summarize ten simple tips to help minimize failures and improve outcomes when positioning iliosacral screws.

Clinical Application of Navigation in the Surgical Treatment of a Pelvic Ring Injury and Acetabular Fracture.

The purpose of this chapter is to review current evidence on indications, techniques, and outcomes of computer-navigated surgical treatment of pelvic ring injuries and acetabular fractures, particularly computer-navigated screw fixation.Iliosacral screw fixation of pelvic ring injury using navigation is attracting attention because the biomechanical stabilization of posterior pelvic ring disruption is of primary importance and is widely indicated because it does not require complete reduction of the fracture site. A cadaver study with a simulated zone II sacral fracture demonstrated a substantial compromise in the space available for iliosacral screws with displacements greater than 10 mm. It is possible to reduce the fracture fragment prior to intraoperative imaging in 2D or 3D fluoroscopic navigation. The use of 3D fluoroscopic navigation reportedly results in lower rates of iliosacral screw malpositioning than the use of the conventional technique or 2D fluoroscopic navigation. Moreover, compared with the conventional technique, it reduces radiation exposure and lowers revision rates. However, the malposition rate associated with 3D fluoroscopic navigation ranges from 0% to 31%, demonstrating that there is still room to improve the navigation performance.Conversely, complete articular surface reduction is required when treating a displaced acetabular fracture to prevent residual hip pain and subsequent osteoarthritic changes. Treating a severely displaced acetabular fracture by screw fixation is very challenging, even with the use of 3D fluoroscopic navigation, because of the difficulty in performing closed anatomical reduction. The indication for percutaneous screw fixation is limited to cases with a small articular displacement. Using 3D fluoroscopic navigation for open surgeries reportedly improves the quality of radiographic fracture reduction, limits the need for an extended approach, and lowers the complication rate.In conclusion, percutaneous screw fixation for pelvic ring injuries is widely indicated, and navigation makes these procedures safe and reliable. The indication for percutaneous screw fixation of acetabular fractures is limited to cases with a small articular displacement. Using 3D fluoroscopic navigation when performing open surgeries is reported to be useful in evaluating fracture reduction and screw position.

Closed Reduction in a "Hyperextended Supine Position" with Percutaneous Transsacral-Transiliac and Iliosacral Screw Fixation for Denis Zone III Sacral Fractures.

Background Herein, we demonstrate the clinical results of closed reduction in a hyperextended supine position with transsacral-transiliac (TSTI) and iliosacral (IS) screw fixations for Denis zone III sacral fractures. Patients and Methods Sixteen consecutive patients with Denis zone III sacral fractures who were treated between January 2009 and September 2016 were evaluated. All patients were treated using percutaneous TSTI/IS screw fixation during closed reduction performed with patients placed in a hyperextended supine position with body manipulation. The clinical and radiological results were evaluated, and the neurological outcomes were retrospectively assessed using Gibbon's classification system. The clinical outcomes were evaluated using the German Multicenter Study Group Pelvic Outcome Scale (POS). Results The sacral kyphotic angle was reduced by 18.06° ± 15.26° (mean kyphotic angle: pre-OP, 39.44° ± 20.56°; post-OP, 21.38° ± 7.39°), and fracture translation was reduced by 5.93 ± 4.95 mm (mean fracture translation: pre-OP, 8.69 ± 8.03 mm; post-OP 2.75 ± 3.97 mm). The mean initial Gibbon's score was 3.00 ± 1.32. Among 15 patients with a follow-up duration of over 12 months, the mean reduction loss in the sacral kyphotic angle was 5.87° ± 10.40° and was 1.00 ± 3.00 mm for the fracture translation. The final Gibbon's score was 1.80 ± 1.21, and 73.3% of patients had good results based on the POS score. Conclusions Although closed reduction in a hyperextended supine position with percutaneous posterior screw fixation is associated with some surgical limitations and technical difficulties, the procedure is minimally invasive and highly effective for stabilizing Denis zone III sacral fractures.