Unstable Posterior Pelvic Ring Injuries Research Articles

Treatment options for unstable posterior pelvic ring lesions: A multicenter retrospective cohort study of the Italian Society for the Traumatology of the Pelvis

PurposePosterior pelvic ring lesions are a common finding in patients with pelvic trauma, representing a challenging condition for trauma surgeons. Surgical options are different and there is not yet evidence about the best option. Aim of the study are: (i) to compare Lumbopelvic fixation (LPF) and ilio-sacral screw fixation (ISS) regarding clinical and radiological outcome in unstable posterior pelvic ring injuries, both as whole population and single similar fracture types according to Tile classification (C1vsC1, C2vsC2, C3vsC3); (ii) to analyze clinical outcomes and complications in lumbopelvic fixation group, comparing open and closed reduction technique. MethodsA retrospective multicenter study was performed. Data of the patients were collected. Inclusion criteria were: (i) unstable posterior ring lesions Tile C type, (ii) surgically treated either through ISS (Group A) or LPF (Group B), (iii) minimum follow-up 12 months. Radiological evaluation was made through plain radiographs in Antero-posterior (AP), inlet and outlet views. Last clinical evaluation at 12 months was assessed through Majeed Score, and quality of life (QoL) through SF-12. ResultsGroup A was represented by 76 patients, and Group B by 42. Group B had better result in Majeed score for non-workers (average 60.1 ± 21.6 vs 65.0 ± 15.6, p = 0.016*). Comparing only C3-type lesions, Group A showed a higher rate of implants breakage (p = 0.032*). Other differences had p > 0.05. Comparing patients underwent open (ORIF) or closed (CRIF) reduction in Group B, CRIF group had shorter hospitalization (47.2 vs 23.4 days, p = 0.020*), an earlier full weight-bearing recovery (4.1 vs 2.6 months, p = 0.035*) and a better Majeed score in workers patients (70.3 vs 82.8, p = 0.019*). Better results for CRIF group were also recorded in quality of life (QoL), both in mental (45.1 vs 55.2, p = 0.040*) and physical outcome (31.9 vs 50.7, p < 0.001*). ConclusionISS and LPF represent both good choices in posterior pelvic ring lesions, however some significant differences were noted. LPF seems to be preferable if the patient did not work before the trauma, due to better clinical outcome. In Tile C3 lesions, LPF have lower breakage rates. If LPF is chosen, CRIF provides better clinical outcomes, QoL and lower hospitalization.

Numerical study of pedicle screw construction and locking compression plate fixation in posterior pelvic ring injuries: Analyzed by finite element method.

The aim of this study was to compare the biomechanical performance of pedicle screw construction and locking compression plate fixation in posterior pelvic ring injuries analyzed by finite element method. A 3-dimensional finite element model of the spine-pelvis-femur complex with ligaments was reconstructed from computed tomography images. An unstable posterior pelvic ring injury was created, which was fixed with a pedicle screw construction or locking compression plate. A follower load of 400 N was applied to the upper surface of the vertebrae to simulate the upper body weight, while the ends of the proximal femurs were fixed. The construct stiffness, the maximum vertical displacement, the maximum posterior displacement, the maximum right displacement, and the overall maximum displacement of the sacrum, and stress distributions of the implants and pelvises were assessed. The construct stiffness of the pedicle screw model (435.14 N/mm) was 2 times that of the plate model (217.01 N/mm). The maximum vertical displacement, the maximum posterior displacement, the maximum right displacement, and the overall maximum displacement of the sacrum in the pedicle screw model were smaller than those in the plate model (0.919, 1.299, 0.259, and 1.413 mm in the pedicle screw model, and 1.843, 2.300, 1.053, and 2.895 mm in the plate model, respectively). The peak stresses of the implant and pelvis in the pedicle screw model decreased by 80.4% and 25% when compared with the plate model (44.57 and 34.48 MPa in the pedicle screw model, and 227.47 and 45.97 MPa in the plate model, respectively). The study suggested that the pedicle screw construction could provide better fixation stability than the locking compression plate and serves as the recommended fixation method for the treatment of posterior pelvic ring injuries.

Safe surgical corridor for iliosacral screw placement in unstable pelvic fractures: a computed-tomography-guided validation study of the “triangulation method”

BackgroundThe percutaneous iliosacral screw technique represents a global standard fixation method for unstable fractures of the posterior pelvic ring. However, the inaccurate positioning of iliosacral screws is associated with a significant risk of severe intra-operative complications. Therefore, this study aimed to investigate the relationship between the skin entry point of the transverse iliosacral screw of the first sacral vertebral body and the anterior superior iliac spine and the greater trochanter of the femur using computed-tomography-guided validation.MethodsOverall, 91 consecutive patients admitted to a tertiary referral center in China for posterior pelvic ring fixation via the “triangulation method” using computed-tomography-guided validation between January 1, 2020, and December 31, 2020, were included in this retrospective observational cohort study. Modeling and simulated iliosacral screw placement were performed using the Mimics software. The distance between the three points of interest was measured, and their relationship in a rectangular coordinate system was determined. Patients were categorized according to gender, body mass index, and femoral rotation angle to investigate the factors affecting the positional relationship between the three points.ResultsAn equilateral triangular relationship was observed between the positioning points of the transverse iliosacral screw, anterior iliac spine, and greater trochanter. Additionally, 95% of the entry points were within a circle radius centered 12 mm at the apex of an equilateral triangle comprising the anterior superior iliac spine and the greater trochanter as the base. The entry point in the femoral external rotation was more dorsal than that in the internal femoral rotation. Furthermore, the entry point in females was more rostral than that in males, and the entry point in overweight patients was more dorsal than that in normal-weight patients.ConclusionsThe skin entry point of the percutaneous iliosacral screw can be located by drawing an equilateral triangle from the anterior superior iliac spine and the greater trochanter as the base to the dorsum end of the patient’s head. In summary, this retrospective cohort study validated the safety and efficacy of the “triangulation methods” for percutaneous fixation of unstable posterior pelvic ring injuries.

Quantification of the Safe Zone of the First to Third Sacral Segments for Transiliac-Transsacral Screw Fixation in Normal and Dysmorphic Sacra.

Transiliac-transsacral screw fixation is widely used to stabilize unstable posterior pelvic ring injuries. Preoperative radiographic assessment of the safe osseous corridor is necessary because the safe space of sacrum is narrower for transiliac-transsacral screw placement than for traditional iliosacral screw placement. However, the radiographic assessment has rarely been studied in the Taiwanese population. We retrospectively analyzed 100 patients with pelvic computed tomography images and divided them into normal and dysmorphic pelvis groups. To determine the safe osseous space, we recorded cross-section area, cross-sectional diameter of the safe zone (CS-szD), and safe zone width on axial view (Ax-szW) in the S1 to S3 segments. The prevalence of dysmorphic pelvis was 48% among all patients. In the S1 segment, no differences were found in the cross-section area and CS-szD been the two groups. However, the Ax-szW was significantly smaller in the dysmorphic pelvis group. In the S2 segment, the cross-section area, CS-szD, and Ax-szW were all significantly larger in the dysmorphic pelvis group. In the S3 segment, the cross-section area and CS-szD of the normal pelvis group were both significantly smaller. No differences were found in the Ax-szW between the two groups. Based on our findings in a Taiwanese population, S1 was the most suitable segment for transiliac-transsacral screw fixation in a normal pelvis, whereas S2, followed by S3, was most suitable in a dysmorphic pelvis. This study offers surgeons information on identifying the optimal sacral segment for transiliac-transsacral screw placement for each pelvic morphology. [Orthopedics. 2024;47(1):e13-e18.].

RADIOLOGICAL CLASSIFICATION OF THE PELVIS: A TOOL FOR TRAUMA SURGERY PLANNING

Variations in pelvic anatomy are a major risk factor for misplaced percutaneous sacroiliac screws used to treat unstable posterior pelvic ring injuries. A better understanding of pelvic morphology improves preoperative planning and therefore minimises the risk of malpositioned screws, neurological or vascular injuries, failed fixation or malreduction. Hence a classification system which identifies the clinically important anatomical variations of the sacrum would improve communication among pelvic surgeons and inform treatment strategy.300 Pelvic CT scans from skeletally mature trauma patients that did not have pre-existing posterior pelvic pathology were identified. Axial and coronal transosseous corridor widths at both S1 and S2 were recorded. Additionally, the S1 lateral mass angle were also calculated. Pelvises were classified based upon the sacroiliac joint (SIJ) height using the midpoint of the anterior cortex of L5 as a reference point. Four distinct types could be identified:Type-A – SIJ height is above the midpoint of the anterior cortex of the L5 vertebra.Type-B – SIJ height is between the midpoint and the lowest point of the anterior cortex of the L5 vertebra.Type-C – SIJ height is below the lowest point of the anterior cortex of the L5 vertebra.Type-D – a subgroup for those with a lumbosacral transitional vertebra, in particular a sacralised L5.Differences in transosseous corridor widths and lateral mass angles between classification types were assessed using two-way ANOVAs.Type-B was the most common pelvic type followed by Type-A, Type-C, and Type-D. Significant differences in the axial and coronal corridors was observed for all pelvic types at each level. Lateral mass angles increased from Types-A to C, but were smaller in Type-D.This classification system offers a guide to surgeons navigating variable pelvic anatomy and understanding how it is associated with the differences in transosseous sacral corridors. It can assist surgeons’ preoperative planning of screw position, choice of fixation or the need for technological assistance.

The efficacy of “TiRobot”orthopaedic robot-assisted VS conventional fluoroscopic percutaneous screw fixation of the sacroiliac joint

PurposeThis study is to compare the precision and safety of the orthopaedic robot with conventional fluoroscopy for assisted percutaneous sacroiliac joint screw implantation.MethodsRetrospective analysis was performed on the clinical data of 57 patients with unstable posterior pelvic ring injuries who were admitted and met the criteria between January 2017 and January 2022. All of these patients underwent percutaneous sacroiliac joint screw implantation, and their clinical data were split into two groups based on the surgical technique: a RA group (robot-assisted implantation, 30 patients, 54 screws) and a CF group (conventional fluoroscopic freehand implantation, 27 patients, 42 screws). There were 96 screws placed in total. The durations of the two groups’ operations, fluoroscopy examinations, fluoroscopy doses, total number of fluoroscopies, and intra-operative guide pin applications were noted and compared. On post-operative CT scans, the placement of each screw was assessed using the Gertzbein-Robbins classification. Finally, imaging Matta criteria were used to assess the sacroiliac joint fracture reduction. The Majeed functional score was used to assess clinical function.ResultsBoth groups successfully completed 57 procedures in total. In both groups, there were no consequences from vascular injury, wound infection, or urinary tract infection. Additionally, there were no complications from robotic-induced nerve injury, operating time, fluoroscopic dose, and the frequency of fluoroscopic; the number of percutaneous punctures in the RA group was lower than that of the CF group.There were statistically significant differences between the aforementioned data (P < 0.05). The modified Matta evaluated the effectiveness of fracture reduction. In the RA group, there was no statistically significant difference between the CF group (P > 0.05). According to the modified Gertzbein-Robbins classification criteria, the 54 screws implanted in the RA group were classified as follows: class A (45), class B (5), class C (4), and class D (0); the accuracy rate of the implants was 92.59%. Forty-two screws implanted in the CF group, 30 screws were defined class A, class B (3), class C (7), and class D (2). The accuracy rate of the implants was 78.57%(χ2 = 3.967, P < 0.05). There was a statistically significant difference between the two groups. The Majeed score 30 patients in RA group, one month post-operation, 16 considered exceptional, eight decent, six moderate, and zero bad. Post-operation more than six months,25 recorded exceptional, five decent. By the time,27 patients in CF group,12 exceptional grade, eight decent, six moderate, and one bad,one month post-operation. Post-operation more than six months,22 recorded exceptional, five decent.Both group (P > 0.05).Conclusion“TiRobot” robot-assisted screw implant treatment for unstable posterior pelvic ring injury has a greater success rate than traditional surgery as compared to conventional percutaneous screw implant. It is a precise, secure, and minimally invasive surgical technique that can also be applied to severe pelvic injuries even congenital sacral deformities.

Minimally invasive transiliac anatomical locking plate for posterior pelvic ring injury: a retrospective analysis of clinical outcomes and radiographic parameters for the gull wing plate

BackgroundPosterior pelvic ring injuries are challenging for surgeons to treat adequately due to difficulties with reduction and stabilization. Surgical intervention is a beneficial option to protect neurological structures and provide sufficient stability for early mobilization. The gull wing plate (GWP) is a pre-contoured anatomical locking plate with six screws, and its design is unique among posterior transiliac tension-band plates. The purpose of this study was to investigate clinical results of the GWP.MethodsPatients who had an unstable posterior pelvic ring injury and underwent internal fixation with GWP were retrospectively analyzed at a trauma center. Demographic data, fracture type, perioperative data, and radiological evaluation with computed tomography (CT) were collected. Clinical outcomes were graded using the functional independence measure (FIM) and Majeed outcome score.ResultsTwenty-six patients were enrolled (mean age, 54 years), and the mean follow-up period was 23 months. The mean Injury Severity Score was 24 points, and internal fixation was performed 6.6 days post-trauma. CT evaluation showed the lateral surface angle of the uninjured ilium was approximately 68°. The GWP pre-contoured anatomical design closely matched this angle. The mean FIM and Majeed score were 119 and 76 points, respectively, which were graded as excellent (n = 14), good (n = 9), or fair (n = 3).ConclusionsWith the retrospective single-center data available, the GWP seems to be a minimally-invasive alternative, provides reliable stability of the posterior pelvic ring and allows for rehabilitation within normal ranges.

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

BackgroundThe 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.MethodsFrom 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.ResultsIn 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).ConclusionsPreoperative 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.

Percutaneous Robot-Assisted versus Freehand S2 Iliosacral Screw Fixation in Unstable Posterior Pelvic Ring Fracture.

ObjectivesTo assess the efficiency, safety, and accuracy of S2 (IS) screw fixation using a robot‐assisted method compared with a freehand method.MethodsThis is a retrospective clinical study. We analyzed the patients treated with S2 IS screw fixation for unstable pelvic fractures from January 2016 to January 2019 in our institution. Sixty‐three patients (17 men and 46 women) aged between 21 and 55 years (with an average age of 39.22 ± 9.28) were included in this study. According to the Tile classification, there were 26 (41.3%) type B fractures and 37 (58.7%) type C fractures. All patients were divided into robot‐assisted (RA) group (38 patients) or the traditional freehand (FH) group (25 patients). In RA group, the S2 IS screws were implanted with a robot‐assisted technique. And S2 IS screws were implanted with a traditional freehand technique in FH group. The screw‐related complications were recorded during and after the surgery. The position of all screws and fracture reduction was assessed by postoperative CT scans according to the Gras classification. The number of guide wire attempts and the radiation exposure for S2 screw implantation during operation were also recorded. Finally, the Matta standard was used to evaluate the fracture reduction of the IS joint.ResultsA total of 89 IS screws were implanted into S2 iliosacral joint. Fifty‐four screws were placed by RA (38 patients) and 35 screws were by FH (25 patients). There was no difference between the two groups with respect to demographic data. There was no screw‐related complications or revision surgery in any group. In terms of screw placement, the excellent and good rate was 100% in the RA group, better than that in the FH group where it was only 85.7% (P < 0.001). The fluoroscopy time was 8.06 ± 3.54 s in RA group, which was much less than that in the FH group (27.37 ± 8.82 s, P < 0.001). The guide wire attempts in the RA group (0.685 ± 0.820) were much less than those in the FH group (5.77 ± 3.34) (P < 0.001). Both the fluoroscopy time per screw and the number of guide wire attempts in the RA group were much less than those in the FH group (P < 0.001). The overall postoperative excellent and good rate of Matta standard in RA and FH groups were 86.8% (34/4) and 90.0% (23/25), respectively (P = 0.750), and there was no statistical difference.ConclusionThe robot‐assisted surgery is an accurate and minimally invasive technique. S2 IS screw implantation assisted by TiRobot to treat the posterior pelvic ring fractures, have a high success rate than the freehand technique. Percutaneous RA S2 IS screw fixation for unstable posterior pelvic ring injuries is safe and clinically feasible and has great clinical application value.

Treatment of Unstable Posterior Pelvic Ring Injury with S2-Alar-Iliac Screw and S1 Pedicle Screw Fixation

The S2-alar-iliac (S2AI) screws have been described as an alternative method for lumbosacropelvic fixation in place of iliac screws. However, the clinical effect of the short-segment S2AI screw fixation technique in the treatment of unstable posterior pelvic ring injuries remains unclear. In this study, we report the preliminary clinical results of the internal fixation connecting a S2-alar-iliac screw and a S1 pedicle screw (i.e., S2AI-S1 fixation) in the treatment of unstable pelvic posterior ring injuries. Twenty-five patients with unstable posterior pelvic ring injury were treated with S2AI-S1 fixation from February 2019 to June 2020. The incision length, surgical time, blood loss, frequency of intraoperative fluoroscopy, quality of reduction, complications, and functional outcome were analyzed. A total of 29 groups of S2AI-S1 fixation were used in 25 patients. The mean incision length was 8.3 (6.2- 10.3) cm, mean operative time was 86.4 (60- 142) minutes, mean frequency of intraoperative fluoroscopy was 7.9 (4- 12) times, and mean blood loss was 148 (50- 500) mL. The mean postoperative follow-up time was 17.8 (10- 26) months. The satisfaction rate of pelvic reduction quality was 25/29, and the satisfactory rate of functional outcome was 23/25. There were no obvious signs of screw prominence, screw loosening, or implant failure. The case series presented in this study show the successful use of S2AI-S1 fixation to treat unstable posterior pelvic ring injuries. The S2AI-S1 fixation, not including the lumbar spine in the fixation range, is a simple, safe, and effective fixation method.

Technical Note on Placement of Low-Profile Triangular Osteosynthesis for Unstable Posterior Pelvic Ring Injuries.

Triangular osteosynthesis is a technique used to stabilize posterior pelvic ring injuries. Conventional triangular fixation can be problematic for several reasons, including the need for advanced skill sets to place instrumentation, difficulty with pelvic reduction and placing the connecting construct, and prominent instrumentation. The purpose of this study is 2-fold: (1) to describe in detail a technique for lumbopelvic fixation using implants that are easy to connect, allow distraction for complex lumbosacral displacements, and are placed in a location minimizing soft tissue prominence and (2) to present our initial case series using this technique. We present a retrospective review of 18 consecutively treated patients with this technique. Inclusion criteria were patients with complete disruption through the sacrum or sacroiliac joint from blunt trauma (OTA/AO type C injuries). Outcomes included pelvic reduction/malreduction, wound healing, and complications. Fourteen patients underwent unilateral fixation (81%), and 4 patients underwent bilateral fixation (19%). All patients (18 of the 18) had a well-reduced pelvis after fixation. No patient (0%) required a return trip to the operating room for loss of reduction/malreduction, wound breakdown, or implant failure. This study presents an updated technique for a low-profile triangular osteosynthesis construct with straightforward application for unstable posterior pelvic ring injuries. This technique does not require rod bending, results in a consistently more recessed iliac screw and connecting rod, and can be used in a wide variety of unstable posterior pelvic ring injuries, including comminuted sacral fractures, L5/S1 facet fractures, and vertical shear injuries.

Analysis of trans-sacral corridors in stabilization of fractures of the pelvic ring.

Percutaneous screw fixation combined with pelvic reduction is a surgical technique used to stabilize fractures of the posterior pelvic ring. This is the standard surgical treatment of unstable posterior pelvic ring injuries. The primary goal of this treatment is an anatomic reduction and stable fixation. This has been shown to reduce pain and improve the patients' long-term well-being. The aim of this analysis was to determine the possible screw lengths and the positioning of the screws in the S1 and S2 sacral segments. A population of 697 pelvises from the Stryker Orthopaedic Modeling and Analytics database were analyzed. The dimensions of the S1 and S2 screw corridors were determined and after assessing for sacral dysmorphism, the correct screw placement was chosen to determine the necessary screw length for surgical treatment. The measurements of the screw lengths show a Gaussian distribution for the analyzed population. The percentage of dysmorphic pelvises for the S1 screw corridor was 31.3% and for the S2 corridor 8%. Average screw length for S1 was 163.8 ± 16.2 mm and for the S2 137.3 ± 9.5 mm. The results show that the S1/S2 axis cannot be used for a trans-sacral screw placement in every patient. The study shows that intraosseous screw corridors are present in 68.7% of the patients in the S1 position and in 92% at the S2 level where an intended implant can be placed fully intraosseous.

Early results of iliosacral screw(s) fixation in the treatment of Tile’s type C unstable pelvic injuries

Background Pelvic ring disruptions are associated with increased patients’ morbidity and mortality. Several methods have been advocated for treatment of such devastating injuries. Surgical fixation is now regarded as the treatment of choice of unstable pelvic disruptions. Among different methods of surgical fixation, iliosacral screws (ISS) have shown promising results in the treatment of the disruption of the posterior pelvic ring. Aim The aim of this study was to report the clinical and radiological results of ISS for fixation of the posterior pelvic disruption in completely unstable pelvic ring injury (Tile’s C). Settings and design A prospective study was held at Alexandria University. Patients and methods This study involved a prospective assessment of 27 patients with Tile’s C pelvic disruption who had ISS fixation. The mean duration of postoperative follow up was 28.96±9.28 (12–49) months. The clinical outcome was assessed with postoperative Majeed score and the rate of the postoperative complications. The radiological outcome was evaluated by the degree of postoperative displacement on the anteroposterior plain radiographs. Statistical analysis SPSS version 20.0. Results The mean postoperative Majeed score was 79.11±13.01. There was a statistically significant improvement in the postoperative vertical displacement (P Conclusion Fixation with ISS is an effective procedure in the management of completely unstable posterior pelvic ring injuries.

Robot-assisted S2 screw fixation for posterior pelvic ring injury

BackgroundPercutaneous sacroiliac screw is one of the main methods to treat unstable posterior pelvic ring injury. However, complexity of pelvic anatomical structure increases the difficulty and risk with freehand operation. Besides, S2 screw fixation began to receive attention. The purpose of the current study was to evaluate the safety, accuracy, efficiency and clinical outcome of robot-assisted S2 screw fixation for posterior pelvic ring injury. MethodsWe reviewed 128 cases of unstable posterior pelvic ring injury treated by percutaneous sacroiliac screw fixation in our hospital from January 2016 to January 2020. All cases were divided into robot-assisted S1 group (RAS1), robot-assisted S2 group (RAS2), freehand group S1 group (FHS1) and freehand group S2 group (FHS2). The mean times of fluoroscopy per screw and adjustment per guide wire were used to evaluate radiation exposure and the efficiency of screw placement, respectively. The final position of the screw was evaluated with postoperative CT to illustrate security and accuracy. 108 patients (84.38%) were followed up for 5~24 months and the Majeed scores were compared among groups. ResultsA total of 180 screws were inserted. In comparison of the mean times of fluoroscopy per screw and adjustment per guide wire, RA group was significant less than FH group, further comparison revealed that freehand S2 placement need more fluoroscopy and adjustment times compared with freehand S1 placement, but for robot-assisted procedure, there was no difference between placing S1 and S2. Screw penetration was found in the FHS1(3/48) and FHS2(2/14) and none in RAS1 or RAS2, which means robot-assisted groups were more safety and accurate (P<0.001). The mean Majeed score in RAS1 (83.33±13.47) and RAS2 (82.32±11.42) was higher than in FHS1 (80.43±12.25) and FHS2 (75.08±18.47), but this difference failed to reach significant. ConclusionCompared with the freehand operation, TiRobot increased the safety and accuracy, reduced radiation exposure, and improved the efficiency. TiRobot could reduce the risk of S2 placement and provide a safe and feasible way for clinical practice.

Part 1: Outcome of Posterior Pelvic Ring Injuries and Associated Prognostic Factors - A Five-Year Retrospective Study of One Hundred and Sixty Five Operated Cases with Closed Reduction and Percutaneous Fixation.

The aim of this study was to evaluate: 1. the outcome of pelvic ring fractures treated by closed reduction and percutaneous fixation, 2. the prognostic factors associated with a poor quality reduction, 3. the prognostic factors associated with ilio-sacral screws misplacement and 4. the prognostic factors associated with nonunion. Data from medical charts for all patients admitted with unstable posterior pelvic ring injuries from 2009 to 2013 were extracted. A total of 165 patients with a mean age of 40years were included. One hundred and five patients were reviewed at a mean of 32months of follow-up. The prognostic factors analyzed were clinical and radiological factors. Tile B and Tile C pelvic ring fractures were compared and analyzed separately. Then specific statistical analysis was performed using a logistic regression model to eliminate confusion factors. An excellent or good clinical result was achieved for 94 patients (90%). An excellent or good reduction was achieved for 141 patients (85%). Nonunion rate, smoking patients, bad reductions, age of patients and ISS score were significantly higher in Tile C group. To eliminate confusion factors we used a multivariate analysis logistic regression model. Only unstable vertical bilateral posterior injuries (Tile C2 and C3) were independent prognostic factors for unsatisfactory reduction (p= 0.001; OR = 4.72; CI 95% [2.08-16.72]). Screw misplacement was recorded for 30 patients (16%) and sacral dysmorphia was an associated prognostic factor (p= 0.0001; OR = 15.6; CI95% [3.41-98.11]). Nonunion was recorded for ten patients (6%) and smoking was an associated prognostic factor (p= 0.01, OR = 5.12; CI95% [1.1-24.1]). Posterior pelvic ring fractures treated by closed reduction and percutaneous fixation are associated with excellent/good clinical results if excellent/good reduction and bone healing are achieved without screw misplacement. Bilateral unstable vertical posterior pelvic ring injuries, and sacral dysmorphia are risk factors for bad quality reduction and screw misplacement respectively.

Short term functional outcome of single percutaneous Ilio-sacral screw fixation in posterior pelvic ring injuries

Objective: To evaluate functional outcome of single percutaneous iliosacral screw fixation in posterior pelvic ring injuries. Materials and Methods: 20 adult patients of either sex with partially or completely unstable posterior pelvic ring injuries with or without anterior ring injuries admitted between October 2016 to November 2018 were treated with single percutaneous iliosacral screw fixation. The patients were followed clinically and radiologically at four, ten, sixteen and twenty four weeks and assessed with Majeed Pelvic Score.Results: There were 15 male and 5 female with mean average age of 38.1 with 60% being Tiles Type C and 40% being Tiles type B injuries. Out of 20 patients 17 patients (85%) were found to have excellent functional outcome 2 patients (10%) had Good and 1 patient (5%) had fair functional outcome based on clinical grade of Majeed Pelvic score. 1 patient had screw breakage. No patient had Neurological deficit. No case of infection was reported. Conclusion: The results obtained in our study compare well with other studies undertaken in the past and shows that single percutaneous iliosacral screw fixation is safe and efficacious procedure for fixation of sacral fracture and sacroiliac disruption.

Open versus percutaneous fixation of unstable posterior pelvic ring injuries

Objective This is a prospective clinical study on 40 patients with unstable posterior pelvic ring injuries to compare percutaneous fixation technique with open fixation technique. Background Unstable pelvic ring fractures are usually secondary to high-energy trauma and usually associated with high mortality and morbidity. There are several surgical approaches to the treatment of unstable posterior pelvic ring injury: open or percutaneous screw fixation and plate fixation of posterior pelvic ring injury, each having respective advantages and disadvantages. Patients and methods Two techniques have been used for the fixation of the posterior pelvis, each with advantages and disadvantages specific to the technique. A total of 40 cases of completely unstable pelvic ring injuries type C were managed by either percutaneous techniques (group I included 20 patients) or open reduction and internal fixation (group II included 20 patients). Anatomical reduction and restoration of the length of limb were the main aim during the surgery. Results The data were analyzed as follows. Tile classification, radiological evaluation according to maximal residual displacement at final follow-up, and functional evaluation according to Lindhal scoring system. Forty patients were included, with 31 male and nine female patients. Overall, 11 patients had excellent results, 20 patients had good, eight patients had fair, and one patient had poor. Conclusion Percutaneous fixation of unstable posterior pelvic ring injuries shows better results and fewer complications in comparison with open technique of fixation.

Radiographic and clinical results of iliosacral screw fixation of posterior pelvic ring injuries

Background: Percutaneous iliosacral screw fixation is now the preferred option for posterior pelvic ring stabilization. Outcome reporting for this procedure remains inconsistent and unstandardized. We sought to evaluate the early outcomes of iliosacral screw fixation of unstable posterior pelvic ring injuries, with particular reference to leg-length differences. Methods: We retrospectively reviewed 28 patients who underwent percutaneous iliosacral screw fixation of posterior pelvic ring injuries between 2008 and 2012 at our trauma center. Only those with a minimum of 1-year follow-up, were included. Clinical outcomes were measured with EuroQol (EQ5D) and Majeed pelvic scores, and the radiographic outcomes were measured by the method of Matta and Tornetta. Results: The mean Majeed score was 83, mean EQ-Visual Analog Score (EQ-VAS) was 75; and the two scores correlated with statistical significance. Measured reductions of these injuries were good to excellent. Leg-length discrepancies improved initially but increased on further follow-up. This did not negatively affect the clinical outcome measures. The incidence of multiple surgical procedures in these patients was significantly associated with worse outcomes. Conclusions: Percutaneous iliosacral screw fixation of unstable posterior pelvic ring is performed with high patient-reported outcomes and excellent radiographically measured reductions at this center. We detected a trend towards increased leg-length difference on longer follow-up, but there was no detrimental effect on the clinical progress. We also found a previously unreported correlation between the Majeed score and the EQVAS score in our patient population.

Posterior pelvic plating in the treatment of tile type C unstable pelvic injuries: a prospective study

Introduction Unstable pelvic ring disruptions result from high-energy trauma and are often associated with multiple concomitant injuries. Internal fixation has become the preferred treatment for unstable posterior pelvic ring injuries. Several methods of fixation of posterior pelvic injuries have been described, including anterior pelvic plating, posterior sacroiliac plating, lumbopelvic fixation, and percutaneous fixation with iliosacral screws. Aim The aim of this study was to report on the clinical and radiological results of plate osteosynthesis for fixing posterior pelvic injuries in Tile’s C completely unstable pelvic ring injuries. Patients and methods This study involved 21 patients with Tile type C pelvic injuries who had their posterior injuries fixed by plate osteosynthesis. The mean duration of postoperative follow-up was 25.29±9.93 (13–48) months. The clinical outcome was assessed with postoperative Majeed’s score and the rate of postoperative complications. The radiological outcome was assessed through the measurement of posterior displacement as per the method of Matta and Tornetta. Results The mean±SD postoperative Majeed score was 76.57±11.21. There was a statistically significant improvement in the postoperative vertical displacement of the posterior injury (P Conclusion Pelvic plating is an effective procedure in the management of completely unstable posterior pelvic ring injuries. The treatment of these complex injuries is associated with a relatively high incidence of postoperative complications.

Measurement of Optimal Insertion Angle for Iliosacral Screw Fixation Using Three-Dimensional Computed Tomography Scans.

BackgroundPercutaneous iliosacral screw fixation can provide stable fixation with a minimally invasive surgical technique for unstable posterior pelvic ring injuries. This surgical technique is not limited by cases of difficult fracture patterns, sacral dysplasia, and small sacral pedicles that can occur in Asians. The purpose of this study was to investigate the incidence of the sacral dysplasia in the Korean population and determine the optimal direction of iliosacral screws by analyzing pelvic three-dimensional computed tomography (3D-CT) scans.MethodsOne hundred adult patients who had pelvic 3D-CT scans were evaluated. The upper sacral morphology was classified into three groups, i.e., normal, transitional, and dysplastic groups; the cross-sectional area of the safe zone was measured in each group. S1 pedicle with a short width of more than 11 mm was defined as safe pedicle. The incidences of safe pedicles at different angles ranging from 0° to 15° were investigated in order to determine optimal angle for screw direction.ResultsThe incidence of normal, transitional, and dysplastic group was 46%, 32%, and 22%, respectively. There were significant increases of the cross-sectional area of the safe zones by increasing the angles from 0° to 15° in all groups. The incidence of safe pedicles increased similar to the changes in cross-sectional area. The overall incidence of safe pedicles was highest at the 10° tilt angle.ConclusionsThe incidence of sacral dysplasia in Koreans was 54%, which is higher than previous studies for Western populations. The cross-sectional area of the safe zone can be increased by anteromedial direction of the iliosacral screw. Considering the diversity of sacral morphology present in the Korean population, a tilt angle of 10° may be the safest angle.