Percutaneous Iliosacral Screw Placement Research Articles

Comparison of Computer-Assisted Navigation and 3D Printed Patient-Specific Template for the Iliosacral Screw Placement.

Iliosacral screw insertion by computer-assisted navigation gradually became the main technique in some hospitals, but the expensive price limited the extensive application. But other techniques such as 3D printed template was used to place iliosacral screw as novel method. This study was to compare the efficiency of percutaneous iliosacral screw placement by using patient-specific template and computer-assisted navigation. Total of 58 patients from September 2017 to September 2021 with sacral injury were treated operatively with percutaneous screw technique, which was selected for this retrospective analysis and divided into two groups (template and computer-assisted navigation). There were 31 patients in template group and 27 patients in computer-assisted navigation group. The surgical details (operation time, blood loss, number of screw placements, and number of fluoroscopies), complications, radiographic and clinical results were recorded. The quality of reduction was assessed by the Matta scoring system. T-test and rank-sum test was used in this study. Operation time in template group was less (33.97 ± 16.61 < 60.31 ± 11.46 min, p < 0.01), but the preoperative preparation time was more (6.35 ± 1.60 > 5.41 ± 1.58, p < 0.05). The quality of reduction in both groups was no difference (p = 0.352). A patient was complicated with gluteal vessel injury in operation in navigation group, which was treated with ligation, but the same injury was not observed in template group. The related surgical data of patient with gluteal injury was ignored in statistical analysis. Both of the two techniques could improve surgical efficiency, the operation time in template was less than computer-assisted navigation group, but the preoperative preparation time was more.

Modified percutaneous iliosacral screw and anterior internal fixator technique for treating unstable pelvic fractures: a retrospective study

BackgroundThe commonly used technique for treating unstable pelvic fractures with sacroiliac screws and anterior internal fixator (INFIX) is prone to complications, such as injury to the pelvic vasculature and nerves, life-threatening bleeding, lateral femoral cutaneous neuritis, and wound infection. This study investigated the clinical effects of using a modified percutaneous iliosacral screw and INFIX technique for treating unstable pelvic fractures.MethodsA retrospective analysis of minimally invasive internal fixation using modified incision of an anterior-ring INFIX application combined with modified percutaneous iliosacral screw placement was performed for 22 cases of unstable pelvic fractures from January 2017 to December 2018. Based on the Tile classification, there were 4 type B1, 7 type B2, 5 type B3 and 6 type C1 injuries. Preoperatively, the length and orientation of the internal fixation were computer-simulated and measured. On postoperative day 3, pelvic radiographs and three-dimensional computed tomograms were used to assess fracture reduction and fixation. All patients were regularly followed up at 4 weeks, 12 weeks, 6 months, 12 months, 24 months and annually thereafter. Fracture healing, complications, visual analogue scale (VAS) scores, the quality of fracture repositioning and Majeed score were assessed during follow-up.ResultsAll patients were followed up for a mean of 25.23 ± 1.48 months. All fractures healed without loss of reduction and no patient showed evidence of delayed union or nonunion. Two years postoperatively, the mean VAS score was 0.32 ± 0.09 and the mean Majeed score was 94.32 ± 1.86.ConclusionThe modified percutaneous iliosacral screw technique increases the anterior tilt of the sacroiliac screw by shifting the entry point posteriorly to increase the safety of the screw placement. Downward modification of the INFIX incision reduces the risk of lateral femoral cutaneous nerve injury. This technique is safe, effective and well tolerated by patients.

Screw misplacement in percutaneous posterior pelvic iliosacral screwing with and without navigation: A prospective clinical study of 174 screws in 127 patients

BackgroundRecent studies of iliosacral screw fixation performed using intraoperative navigation systems have shown promising results. The Surgivisio Platform is a new-generation three-dimensional intraoperative navigation tool that has been used at our institution for 2years. The aim of this prospective study was to assess the contribution of navigation in terms of iliosacral screw positioning accuracy and of radiation exposure, by comparing outcomes with vs. without navigation. HypothesisNavigation allows more accurate percutaneous iliosacral screw positioning regardless of the type of screw fixation (with sacral dysmorphism and/or cemented screw fixation and/or multiple screw fixation). Materials and methodsBetween January 2018 and December 2019, consecutive patients who underwent percutaneous iliosacral screw fixation of pelvic ring fractures without vertical instability were included in this single-centre prospective study. Screw position accuracy was evaluated by postoperative high-resolution computed tomography (HRCT). Operative time, radiation dose, and complications were recorded. ResultsWe included 127 patients with 174 iliosacral screws, of which 129 were positioned under fluoroscopic guidance and 45 using navigation. According to the modified Gras classification, 7% (12/174) of the screws were incorrectly positioned and 2% (4/174) required repositioning. The frequency of screw malposition was not significantly different between the fluoroscopy and navigation groups (8.5%, 11/129 vs. 2.2%, 1/45, respectively; p=0.19). However, screw position in dysmorphic sacra was significantly better with navigation (p=0.04), whereas no significant difference in final screw position was found for cemented or multiple screw implantations. In the navigation group, the operative time was significantly longer (28.2min vs. 21.6min, p=0.003), and the mean dose-area product significantly greater (6.6Gy·cm2 vs. 4.9Gy·cm2, p=0.02). The complication rates were not different between the two groups. ConclusionIn patients who have pelvic ring fractures without vertical instability, navigation of percutaneous iliosacral screw placement using the Surgivisio Platform improves screw positioning in dysmorphic sacra, at the cost of a longer operative time and greater radiation exposure of the patient. Level of evidenceII, prospective study.

Feasibility of iliosacral screw placement in patients with upper sacral dysplasia

BackgroundExact knowledge of the sacral anatomy is crucial for the percutaneous insertion of iliosacral screws. However, dysplastic anatomical patterns are common. In addition to a preoperative computed tomography (CT) analysis, conventional radiographic measures may help to identify upper sacral dysplasia and to avoid damage to surrounding structures. Aiming to further increase safety in percutaneous iliosacral screw placement in the presence of sacral dysmorphism, this study examined the prevalence of previously established radiographic signs and, in addition, defined the “critical SI angle” as a new radiographic criterion.MethodsPelvic CT scans of 98 consecutive trauma patients were analysed. Next to assessment of established signs indicating upper sacral dysplasia, the critical sacroiliac (SI) angle was defined in standardized pelvic outlet views.ResultsThe critical SI angle significantly correlates with the presence of mammillary bodies and an intraarticular vacuum phenomenon. With a cut-off value of − 14.2°, the critical SI angle detects the feasibility of a safe iliosacral screw insertion in pelvic outlet views with a sensitivity of 85.9% and a specificity of 85.7%.ConclusionsThe critical SI angle can support the decision-making when planning iliosacral screw fixation. The clinical value of the established signs of upper sacral dysplasia remains uncertain.

Accuracy of navigated and conventional iliosacral screw placement in B- and C-type pelvic ring fractures.

The objective of this study is to report the institutions experiences with standardized 2D computer-navigated percutaneous iliosacral screw placement (CNS), as well as the conventional fluoroscopically assisted screw placement method (CF) over a period of 10years. A total of 604 patients with sacral fractures (OTA B and C) were treated at the institution. Cases with both, a preoperative and postoperative CT scan were included for further analysis. With this prerequisite, a total of 136 cases were included. The quality of screw positioning, length of operation and intraoperative radiation exposure were recorded and compared. Moreover, it was analyzed whether the presence of dysmorphic sacra influenced the precision of screw positioning. Two hundred and thirty-two screws were implanted in 136 patients (100 navigated, 36 conventional). The duration of the average procedure was similar in the two groups [49.8min (p = 0.7) conventional group (CF) vs. 48.0min computer-navigated (CNS) group]. With computer navigation, radiation exposure was significantly reduced by almost half [128.3 vs. 65.2s (p = 0.023)]. Screw placement was more accurate in the navigation group (79.03% CF vs. 86.47% CNS). The presence of dysmorphic sacral foramina or an increased alar slope increased the incidence of screw malpositioning. The conventional percutaneous method and a standardized 2D navigated method have similar rates of malpositioning. Dysmorphic upper sacral foramina and increased alar slope were identified as risk factors for screw malpositioning. Radiation exposure rates were reduced by half when using computer navigation. Therefore, computer navigation in iliosacral screw placement is recommended as method of choice.

Percutaneous Placement of Iliosacral Screws Under the Guidance of Axial View Projection of the S1 Pedicle: a Case Series

The aim of this study was to evaluate the safety and efficacy of percutaneous placement of iliosacral screws under the guidance of axial view projection of the S1 pedicle clinically. This case series includes 58 consecutive unstable pelvic injury patients, which were treated with iliosacral screws between July 2011 and July 2016. Patients were divided into two groups: normal sacrum (n = 31) and dysmorphic sacrum (n = 27). A single orthopedic surgeon operated on all patients, with percutaneous placement of iliosacral screws under the guidance of axial view projection of the S1 pedicle. The time needed for screw insertion and the radiation exposure time were recorded. Chi-squared test and Student t-test were used to analyze the differences between the two groups. Sacral dysmorphism was present in 47% of patients. The median time for screw insertion and radiation exposure time in these two groups showed no statistical difference (P > 0.05). No clinical complications or malpositioned screws occurred in any case. Preoperative pelvic CT is necessary to determine the sacral osseous anatomy. In patients with either a normal or dysmorphic sacrum, iliosacral screws can be placed by this method with less radiation exposure and complications than in the conventional method.

Computer Assisted Surgery for Iliosacral Screw Placement-How Far have we gone?

Unstable pelvic ring injuries require definite operative fixation. While the posterior ring can be fixed utilizing open approaches, percutaneous screw fixation has become the treatment of choice avoiding the complications of open approaches. As the pelvis is a complex three-dimensional (3D) shape with many neurovascular structures situated within it, a thorough knowledge and understanding of the anatomy and radiographic imaging is required to accomplish the task of percutaneous iliosacral screw placement, while avoiding potential complications. Recent advances in computer assisted surgery (CAS) has provided some powerful tools in overcoming the obstacles associated with this procedure. This review examines the evolution of image guided surgery used for iliosacral screw placement, the current available options, and future perspectives.

Image-guided percutaneous internal fixation of sacral fracture

Percutaneous iliosacral screw placement is a technically challenging procedure with a significant complication profile for misplaced screws. The use of stereotactic image guidance has been shown to provide superior accuracy in the placement of spinal instrumentation. Here, the authors describe a novel application of O-arm technology (Medtronic Sofamor Danek, Memphis, TN, USA) to help safely place iliosacral screws for the treatment of a traumatic sacral fracture.

Correlating preoperative imaging with intraoperative fluoroscopy in iliosacral screw placement

BackgroundPercutaneous iliosacral screw placement can successfully stabilize unstable posterior pelvic ring injuries. Intraoperative fluoroscopic imaging is a vital component needed in safely placing iliosacral screws. Obtaining and appropriately interpreting fluoroscopic views can be challenging in certain clinical scenarios. We report on a series of patients to demonstrate how preoperative computed tomography (CT) imaging can be used to anticipate the appropriate intraoperative inlet and outlet fluoroscopic views.Materials and methods24 patients were retrospectively identified with unstable pelvic ring injuries requiring operative fixation using percutaneous iliosacral screws. Utilizing the sagittal reconstructions of the preoperative CT scans, anticipated inlet and outlet angle measurements were calculated. The operative reports were reviewed to determine the angles used intraoperatively. Postoperative CT scans were reviewed for repeat measurements and to determine the location and safety of each screw.ResultsPreoperative CT scans showed an average inlet of 20.5° (7°–37°) and an average outlet of 42.8° (30°–59°). Intraoperative views showed an average inlet of 24.9° (12°–38°) and an average outlet of 42.4° (29°–52°). Postoperative CT scans showed an average inlet of 19.4° (8°–31°) and an average outlet of 43.2° (31°–56°). The average difference from preoperative to intraoperative was 4.4° (−21° to 5°) for the inlet and 0.45° (−9° to 7°) for the outlet. The average difference between the preoperative and postoperative CT was 2.04° (0°–6°) for the inlet and 2.54° (0°–7°) for the outlet.ConclusionThere is significant anatomic variation of the posterior pelvic ring. The preoperative CT sagittal reconstruction images allow for appropriate preoperative planning for anticipated intraoperative fluoroscopic inlet and outlet views within 5°. Having knowledge of the desired intraoperative views preoperatively prepares the surgeon, aids in efficiently obtaining correct intraoperative views, and ultimately assists in safe iliosacral screw placement.Level of evidenceIV, Retrospective case series.

Are two different projections of the inlet view necessary for the percutaneous placement of iliosacral screws?

We hypothesised that the anterior and posterior walls of the body of the first sacral vertebra could be visualised with two different angles of inlet view, owing to the conical shape of the sacrum. Six dry male cadavers with complete pelvic rings and eight dry sacrums with K-wires were used to study the effect of canting (angling the C-arm) the fluoroscope towards the head in 5° increments from 10° to 55°. Fluoroscopic images were taken in each position. Anterior and posterior angles of inclination were measured between the upper sacrum and the vertical line on the lateral view. Three authors separately selected the clearest image for overlapping anterior cortices and the upper sacral canal in the cadaveric models. The dry bone and K-wire models were scored by the authors, being sure to check whether the K-wire was in or out. In the dry bone models the mean score of the relevant inlet position of the anterior or posterior inclination was 8.875 (standard deviation (sd) 0.35), compared with the inlet position of the opposite inclination of -5.75 (sd 4.59). We found that two different inlet views should be used separately to evaluate the borders of the body of the sacrum using anterior and posterior inclination angles of the sacrum, during placement of iliosacral screws.

Pedicle axis view combined by sacral mapping can decrease fluoroscopic shot count in percutaneous iliosacral screw placement

BackgroundPercutaneous iliosacral screw fixation of the posterior pelvic ring is a demanding procedure with high exposure to radiation. The conventional technique includes the use of three classical projections with the C-arm: inlet, outlet, and true lateral views. A projection in the axis of the upper sacral alar pedicles with a 30° cephalad and 30° ventral oblique view would help in obtaining a more accurate visualization of the safe corridor. Two subcutaneously placed K-wires, one placed horizontally and one vertically, may facilitate the starting point and aim changes by offering the surgeon an option for exactly matching the position of the sacrum with the image. The purpose of this study was to detect if the radiation application could be decreased by our new methodology. MethodsSeventeen patients with pelvic posterior ring disruptions, in which percutaneous iliosacral screw placement was indicated, were included in the study. Group 1 comprised 7 patients in whom conventional projections and technique were used. Group 2 comprised 10 patients in whom 30°–30° projection and sacral mapping technique via two subcutaneous K-wires were applied. Radiation exposure time, total fluoroscopic shot count, fluoroscopic shot count needed for only guide wire and screw placement, radiation dose, and complications were compared between the two groups. ResultsThe median number of fluoroscopic images for guide and screw placement was 132 (56–220) and 29.5 (19–83) in Groups 1 and 2, respectively, and the difference was statistically significant (p<0.001). The median total fluoroscopic radiation time was 138 (68–234) and 52 (28–77)s in Groups 1 and 2, respectively, and the difference was significant (p<0.001). Group 1 had a significantly higher median radiation dose than Group 2 [3020 (1502–6032) vs. 1192 (426–2359); (p=0.001)]. ConclusionsIliosacral screw placement with the help of sacral mapping and a fourth view, “30°–30°”, helps the surgeon to markedly reduce the fluoroscopic shots, radiation time and dose during guide wire and screw placement. Level of evidenceTherapeutic, Level II.

CT-guided screw fixation of vertical sacral fractures in local anaesthesia using a standard CT.

To evaluate time efficiency, radiation dose, precision and complications of percutaneous iliosacral screw placement under CT-guidance in local anaesthesia. Retrospective analysis of 143 interventions in 135 patients during a period of 42 months. Implant failures could be evaluated in 85/182 screws and bony healing or refracturing in 46/182 screws. A total of 182 iliosacral screw placements in 179 vertical sacral fractures (105 unilateral, 37 bilateral) took place in 135 patients. 166/179 of the sacral fractures were detected in Denis zone 1,10 in Denis zone 2 and 3 in Denis zone 3. No screw misplacements including the simultaneous bilateral procedures were noted. The average time for a unilateral screw placement was 23 minutes (range: 14 -52 minutes) and 35 minutes (range: 21 - 60 minutes) for simultaneous bilateral screwing. The dose length product was 365 mGy × cm (range: 162 - 1014 mGy × cm) for the unilateral and 470 mGy × cm (range: 270 - 1271 mGy × cm) for the bilateral procedure. 1 gluteal bleeding occurred as the only acute minor complication (0.7 %). Fracture healing was verified with follow-up CTs in 42/46 sacral fractures after screw placement. Backing out occurred in 12/85 screws between 6 and 69 days after intervention. In 8 patients contralateral stress fractures were detected after unilateral screw placement between day 10 and 127 (average: 48 days). CT-guided iliosacral screw placement in sacral fractures is a safe tool providing a very high precision. The radiation dose is in the order of a diagnostic CT of the pelvis for both unilateral and bilateral screws. Contralateral stress fractures in unilateral screw placements have to be considered during the first weeks after intervention.

Iliosacral screw insertion using CT-3D-fluoroscopy matching navigation

BackgroundPercutaneous iliosacral screw insertion requires substantial experience and detailed anatomical knowledge to find the proper entry point and trajectory even with the use of a navigation system. Our hypothesis was that three-dimensional (3D) fluoroscopic navigation combined with a preoperative computed tomography (CT)-based plan could enable surgeons to perform safe and reliable iliosacral screw insertion. The purpose of the current study is two-fold: (1) to demonstrate the navigation accuracy for sacral fractures and sacroiliac dislocations on widely displaced cadaveric pelves; and (2) to report the technical and clinical aspects of percutaneous iliosacral screw insertion using the CT-3D-fluoroscopy matching navigation system. MethodsWe simulated three types of posterior pelvic ring disruptions with vertical displacements of 0, 1, 2 and 3cm using cadaveric pelvic rings. A total of six fiducial markers were fixed to the anterior surface of the sacrum. Target registration error over the sacrum was assessed with the fluoroscopic imaging centre on the second sacral vertebral body. Six patients with pelvic ring fractures underwent percutaneous iliosacral screw placement using the CT-3D-fluoroscopy matching navigation. Three pelvic ring fractures were classified as type B2 and three were classified as type C1 according to the AO-OTA classification. Iliosacral screws for the S1 and S2 vertebra were inserted. ResultsThe mean target registration error over the sacrum was 1.2mm (0.5–1.9mm) in the experimental study. Fracture type and amount of vertical displacement did not affect the target registration error. All 12 screws were positioned correctly in the clinical series. There were no postoperative complications including nerve palsy. The mean deviation between the planned and the inserted screw position was 2.5mm at the screw entry point, 1.8mm at the area around the nerve root tunnels and 2.2mm at the tip of the screw. ConclusionThe CT-3D-fluoroscopy matching navigation system was accurate and robust regardless of pelvic ring fracture type and fragment displacement. Percutaneous iliosacral screw insertion with the navigation system is clinically feasible.

Malposition and revision rates of different imaging modalities for percutaneous iliosacral screw fixation following pelvic fractures: a systematic review and meta-analysis

Percutaneous iliosacral screw placement following pelvic trauma is associated with high rates of revisions, screw malpositioning, the risk of neurological damage and inefficient stability. The correct entry point and the small target corridor may be difficult to visualize using only an image intensifier. Therefore, 2D and 3D image-based navigation and reconstruction techniques could be helpful tools. The aim of this systematic review and meta-analysis was to evaluate the best available evidence regarding the rate of malpositioning and revisions using different techniques for screw implantation, i.e., conventional, 2D and 3D image-based navigation and reconstruction techniques, CT navigation. A systematic review and meta-analysis were performed using the data available on Ovid Medline. 430 studies published between 1/1948 and 2/2011 were identified by two independent investigators. Inclusion criteria were percutaneous iliosacral screw fixation after traumatic pelvic fractures with included revision rate or positioning of the screw, language of the article English or German. Exclusion criteria were osteoporotic fracture, tumor, reviews, epidemiological studies, biomechanical/cadaveric studies, studies about operative technique. For statistical analysis the random effect model was used. A total of 51 studies fulfilled the inclusion requirements describing 2,353 percutaneous screw implantations following pelvic trauma in 1,731 patients. The estimated rate of malposition was 0.1% for 262 screws using CT navigation. This rate was significantly lower (p<0.0001) than for the conventional technique with malposition rate of 2.6% (total 1,832 screws). Using 2D and 3D image-based navigation and reconstruction techniques, the malposition rate was 1.3% (total 445 screws). No significance was observed between the conventional and the 2D and 3D image-based navigation and reconstruction techniques. The rates of revision were not statistically significant with 2.7% (1,832 implantations) in the conventional group, 1.3% (445 implantations) in the group of 2D and 3D image-based navigation and reconstruction techniques and 0.8% (262 implantations) using the CT navigation. CT navigation has the lowest rate of screw malposition, but on the other hand it could not be used for all type of fractures where surgical procedures (reduction maneuvers, additional osteosynthetic procedures) are necessary. The 2D and 3D image-based navigation and reconstruction techniques provide encouraging results with slightly lower rate of complications compared to the conventional technique and are additional tools to enhance the precision and decrease the rate of revision.

Outcome analysis of unstable posterior ring injury of the pelvis: Comparison between percutaneous iliosacral screw fixation and conservative treatment

Unstable posterior ring injuries of the pelvis are a challenge to pelvic surgeons, and their treatment has been controversial. The functional outcomes of such injuries following either percutaneous iliosacral screw fixation or conservative treatment remain to be elucidated. We conducted a retrospective analysis of 32 consecutive patients with unstable pelvic ring injuries who were treated with percutaneous placement of iliosacral screws (group 1) or conservative means (group 2) from January 2002 to September 2009. Radiographic, clinical, and functional outcomes were compared between the two treatment groups. Patients who underwent percutaneous iliosacral screw fixation after pelvic trauma had better functional results than those treated conservatively, as per the Majeed grading system. In addition, patients in group 1 demonstrated better results for general health and mental health on the 36 item Short Form Health Status Survey. Patients in group 1 also demonstrated less residual displacement on radiography at 1 year follow up than those in group 2. Finally, patients in group 1 had better pain relief at 1 month and 1 year follow ups than those in group 2. Percutaneous iliosacral screw fixation for unstable posterior pelvic ring injuries results in less residual displacement at medium term follow up, and better pain relief at short and medium term follow up, than does conservative treatment. Better functional outcomes were observed at 1 year follow up as compared with conservative treatment.

Percutaneous iliosacral screw fixation in S1 and S2 for posterior pelvic ring injuries: technique and perioperative complications

Percutaneous iliosacral screw placement allows for minimally invasive fixation of posterior pelvic ring instabilities. The objective of this study was to describe the technique for screws in S1 and S2 using conventional C-arm and to evaluate perioperative complications. Thirty-eight consecutive patients after percutaneous pelvic ring fixation with cannulated screws in S1 and S2 using conventional C-arm fluoroscopy were analysed. Accuracy of screw placement, nerval lesions, need for second surgery, operation time, and time to full weight bearing were assessed postoperatively and during regular follow-up examinations. Twenty-one patients underwent unilateral screw fixation and 17 patients underwent bilateral screw fixation. In total, 83 screws were placed. Mean age of the patients was 52 ± 19 years. Mean operation time was 16 ± 7 min/screw. Mean follow-up was 5 ± 3 months. Time to full weight bearing in 28 patients was 9 ± 4 weeks. Eight patients were still not able to support full weight bearing, partially due to concomitant injuries. Patients without concomitant injuries that affected walking were able to bear full weight after 8 ± 4 weeks (n = 17). Two patients had persistent postoperative hypaesthesia. No motor weakness was apparent and no postoperative bleeding was observed. Secondary surgery due to screw malpositioning or loosening had to be performed in four patients. The presence of a screw in S2 was not indicated for perioperative complications. Percutaneous iliosacral screw fixation is a rapid and definitive treatment for posterior pelvic ring injuries with a low risk of secondary bleeding during posterior pelvic stabilization. The technique using standard C-arm fluoroscopy was also found to be safe for screws placed in S2.

Percutaneous Iliosacral Screw Insertion: Malpositioning and Revision Rate of Screws With Regards to Application Technique (Navigated Vs. Conventional)

Conventional percutaneous iliosacral screw placement in pelvic surgery 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. In the conventional technique, the correct entry point for the screw and the small target corridor for the iliosacral screw may be difficult to visualize using an image intensifier. We tried to find out in this study whether the positioning of percutaneous screw implantations could be optimized by evaluating the rate and grade of malpositions and whether the needed revisions could be reduced by using computer navigation and three-dimensional (3D) image intensifier. A group of 54 patients with 63 screws implanted using computer navigation was compared with 87 patients with 131 screws implanted using the conventional fluoroscopic technique. The exact screw position was controlled in a postoperative computed tomography scan, and the grade of malposition of every screw was investigated and compared. A complete intraosseous screw position was found in 42% of cases using the conventional technique and was significantly less compared with 81% using a 3D image intensifier in combination with a navigation system. Moreover, the revision rate of 1.6% was significantly less in the navigated group compared with 19% in the conventional group. The results indicate that 3D-computer navigation of the percutaneous iliosacral screw insertion can facilitate surgical performance in respect to reducing screw malposition and revision rates.

The Application of the Axial View Projection of the S1 Pedicel for Sacroiliac Screw

The objective of this study was to position the iliosacral screws speedily, easily, and safely, we sought to delineate readily reproducible radiographic anatomic clues of the pedicel of S1 for the iliosacral screw placement. We used eight normal adult pelvic specimens lying on the operation table in the prone position. First, the C-arm fluoroscope unit is positioned for the lateral view of the body of S1. We gradually changed the angle of the C-arm to ventral and cephalad. When a clear oval track image appears, we fix the angle of the C-arm. With the assistance of the C-arm projection, the starting point for the guide pin is centered on the oval track, and the orientation is adjusted. When the projection of the guide pin became a point inside of the oval track, the guide pin is inserted using battery-powered equipment. The accuracy and angle of pin placement is assessed using computed tomography scans in all cases. In all the pelves, the oval track has been successfully found, and the guide pins are accurately inserted using the sacral pedicel axial view. In the angular orientations by the computed tomography scan, the transverse plane inclination to the ventral of the guide pin is approximately 38.3 degrees +/- 1.9 degrees, and the frontal plane inclination to the cephalad is approximately 29.6 degrees +/- 2.0 degrees. The sacral pedicel axial view projection is a optimal radiographic technique for percutaneous placement of iliosacral screws in clinical practice. We can get the limpid axial view of pedicel of S1 to applicate this project method, which provides a speedier method with less radiation exposure for percutaneous placement of iliosacral screws.

A Novel Way to Prevent Lost Scalpel Blades During Percutaneous Placement of Iliosacral Screws

Percutaneously placed implants and reduction tools are now commonplace in orthopaedic traumatology. Significant strides toward reducing fractures and maintaining that reduction without additional harm to the soft tissue envelope have been realized. The majority of these percutaneous techniques begin with a simple "stab" incision through the skin into the deeper tissue planes beneath. With withdrawal of the scalpel, there is a possibility of dissociation of the blade relative to its handle. We describe a simple and cost-effective technique to completely eliminate this possibility.

Percutaneous Placement of Iliosacral Screws Without Electrodiagnostic Monitoring

Iliosacral screws are commonly used for fixation of pelvic ring injuries. Previous reports using different screw insertion techniques have reported high neurologic complication rates, leading to recommendations for intraoperative neurodiagnostic monitoring. The purpose of this study was to evaluate the neurologic complications after percutaneous iliosacral screw placement without neurodiagnostic monitoring. During a 21-month period, 326 patients with pelvic ring disruptions were treated at a level 1 trauma center. One hundred seventy-four patients underwent percutaneous stabilization of their pelvic ring injuries without neurodiagnostic monitoring. Patients who were not intubated preoperatively, were neurologically normal, and who underwent a closed reduction were included. Sixty-eight patients who had 106 screws placed met the inclusion criteria and formed the study group. A careful and detailed neurologic examination was performed preoperatively and postoperatively. Plain pelvic radiographs and computed tomography scans were evaluated postoperatively in all patients to assess screw position. No planned screw placement was abandoned because of inadequate fluoroscopic visualization. There were no neurologic injuries as a result of either the closed reduction or the screw placement. Computed tomography scans confirmed the screw position and demonstrated placement as intraosseous in 75 (70.8%) and juxtaforaminal in 31 (29.2%). No screws perforated a nerve root tunnel, spinal canal, or sacral cortex. Using a standardized technique, appropriate and reliable fluoroscopic landmarks are available in the vast majority of percutaneous iliosacral screw fixation procedures. Iliosacral screw placement without neurodiagnostic monitoring has a low rate of neurologic complications.