Pelvic ring fractures internal fixation: iliosacral screws versus sacroiliac hinge fixation

Comparison of sacroiliac screw techniques for unstable sacroiliac joint disruptions: a finite element model analysis

Vertically unstable pelvic injuries associated with sacroiliac disruption are challenging. Although percutaneous iliosacral fixation using two screws at S1 vertebral body has been shown beneficial, the use of two transiliac screws at S1 has been proposed to increase the fixation strength of the construct. In the herein study, the finite element method (FEM) was performed to analyse the biomechanical behaviour of five different constructions using iliosacral screws only, transiliac screws only, and combining an iliosacral and a transiliac screw. A vertically unstable AO 61C1.2 type pelvic injury was produced for the evaluation of the posterior pelvic displacement and implant stress, and the anterior implant stress using FEM. The symphysis pubis was fixed with a 3.5-mm reconstruction plate in all cases. The model was axially loaded with 800N applied in the centre of S1 body, perpendicular to the ground (Y-axis), simulating the bipodal stance moment. There was a statistically significant reduction in both posterior displacement and implant stresses in the groups fixed with at least one transiliac screw compared to the groups fixed with iliosacral screws. In our FEM study, the construct using two transiliac screws in S1 is biomechanically superior for stabilizing the sacroiliac joint in vertically unstable pelvic ring injuries compared to the other configurations. Lateral displacement, posterior displacement, and von Mises stress were reduced with this construct. A good option can be the use of one iliosacral screw and one transiliac screw in S1.

Contemplate iliosacral screw in patients with developmental dysplasia of the hip

OBJECTIVES

Our aim in the study was evaluating sacroiliac morphology in patients with DDH and its possible effect on appropriate iliosacral screw fixation.

DESIGN

Retrospective cohort study.

SETTING

Level of evidence 3.

PATIENTS/PARTICIPANTS

We evaluated the anteroposterior pelvis X-ray and pelvic CT scans of patients. We mainly divided the patients into two groups: DDH group (n:105) and control group (n:105).

INTERVENTION

The presence of the five qualitative characteristics of sacral dysplasia evaluated according to Route in both groups. The DDH group was divided into four subgroups according to the degree of hip dysplasia.

MAIN OUTCOME MEASUREMENT

The cross-sectional area, length of the osseous corridor, coronal and vertical angulation evaluated in both groups.

RESULTS

The DDH group also exhibited a significantly higher S1 coronal and axial angulation, lower S1 cross-sectional area and S1 iliosacral screw length than the control group (p:0.033, p:0,002, p:0.006, p:0,019, respectively). According to the Rout classification, 9% were normal, 31% transient, 58% dysplastic in the DDH group. 45.7% were normal, 38% transient, 17% dysplastic in the control groups. These differences between the groups were statistically significant (p < 0.001). When the DDH groups were evaluated within themselves; no statistically significant difference was observed in S1 and S2 cross-sectional area, S1 and S2 maximum estimated iliosacral screw length, S1 and S2 axial and coronal angles assessment.

CONCLUSION

Sacral dysplasia was more common, narrower and more angled osseous canal for the iliosacral screw was found in the DDH group. There was no relation between the degree of hip dysplasia and sacrum morphology in the DDH group. Thus, we suggest the surgeons be aware of iatrogenic injury even in constrained dysplastic hips.

Posterior hinge fixation for the treatment of unstable traumatic sacroiliac joint injuries

INTRODUCTION

Posterior hinge fixation (PHF) is a sacroiliac joint fixation method indicated for the surgical treatment of unstable pelvic ring fractures (tile C).

HYPOTHESIS

PHF yields good functional outcomes based on the Majeed score at more than 1 year of follow-up.

METHODS

A single-center, retrospective study of patients who had a Tile C pelvic ring fracture, who were operated by PHF and who were evaluated at a minimum follow-up of 1 year. The functional outcome was determined using the Majeed score and pain was evaluated by the patients using a visual analog scale (VAS). The preoperative, intraoperative and postoperative data, complications and sequelae were documented. A CT-scan was done at least 1 year after the surgical treatment to determine the SI joint's reduction and fusion.

RESULTS

Included were 22 patients (59% men) who had a mean age of 37.3±11.9 years; 21 of these patients were reviewed at a mean of 4.8±4 years. The mean Majeed score at the final assessment was 76.4 points±15.3, with 24% of patients having excellent results (n=5), 53% having good results (n=11), 19% having average results (n=4) and 5% having poor results (n=1). The mean pain level on VAS was 28±23mm. Of the eight surgical site infections, seven occurred in the PHF (88%). CT-scans taken at 1 year postoperative were compared to the preoperative scans. The pelvic opening was reduced by -9±6 (p<0.01), SI diastasis by -11mm±9 (p<0.001), vertical displacement by-7mm±8 (p<0.001), symphysis opening by -15mm±15 (p<0.001), median transverse diameter by -10mm±9 (p<0.001) and bispinal diameter by -5mm±7 (p<0.001). SI fusion was confirmed in 43% of patients (n=9).

CONCLUSION

PHF is a surgical instrumentation method that provides satisfactory long-term reduction of Tile C pelvic ring fractures. The clinical outcomes are good or excellent in 77% of cases. The perioperative morbidity is marked by surgical site infections, all of which healed.

LEVEL OF EVIDENCE

IV; retrospective, non-comparative cohort study.

Biomechanical models of in vitro constructs for spinopelvic osteosynthesis

Spinopelvic lesions are the result of high-energy vertical trauma with axial skeletal overload where the spine impacts onto the sacrum, dissociating the lumbar spine from the pelvis. Therefore, lumbopelvic instrumentations are aimed to counteract these vertical forces, although various biomechanical aspects of the combinations of different constructs (with or without iliosacral screws) or the number of lumbar fixation levels (L5 or the combination of L5 with L4) are subject to controversy. The number of patients in each published series is too short, and the nature of the fixation is very different from one article to another, making comparison very difficult. In this paper the methodology for laboratory studies is discussed. The design of the test bench fixture, biomechanical testing protocol and data analysis are very important when inference to the clinical setting is desired.

Calibration and Registration of a Freehand Video-Guided Surgical Drill for Orthopaedic Trauma

Pelvic trauma surgical procedures rely heavily on guidance with 2D fluoroscopy views for navigation in complex bone corridors. This "fluoro-hunting" paradigm results in extended radiation exposure and possible suboptimal guidewire placement from limited visualization of the fractures site with overlapped anatomy in 2D fluoroscopy. A novel computer vision-based navigation system for freehand guidewire insertion is proposed. The navigation framework is compatible with the rapid workflow in trauma surgery and bridges the gap between intraoperative fluoroscopy and preoperative CT images. The system uses a drill-mounted camera to detect and track poses of simple multimodality (optical/radiographic) markers for registration of the drill axis to fluoroscopy and, in turn, to CT. Surgical navigation is achieved with real-time display of the drill axis position on fluoroscopy views and, optionally, in 3D on the preoperative CT. The camera was corrected for lens distortion effects and calibrated for 3D pose estimation. Custom marker jigs were constructed to calibrate the drill axis and tooltip with respect to the camera frame. A testing platform for evaluation of the navigation system was developed, including a robotic arm for precise, repeatable, placement of the drill. Experiments were conducted for hand-eye calibration between the drill-mounted camera and the robot using the Park and Martin solver. Experiments using checkerboard calibration demonstrated subpixel accuracy [-0.01 ± 0.23 px] for camera distortion correction. The drill axis was calibrated using a cylindrical model and demonstrated sub-mm accuracy [0.14 ± 0.70 mm] and sub-degree angular deviation.

Posterior transiliac plating in vertically unstable sacral fracture

The aim of the present technical note is to describe the posterior transiliac plating method. Acute-phase clinical and radiological results in a continuous series of 10 vertically unstable fractures are presented. Reduction was good or excellent in 70% of cases, and clinical results were good or excellent in 80% on Hannover and Majeed scores, with mean Majeed score of 71.8±17. Complications comprised 3 cases of early postoperative sepsis requiring surgical lavage, and 4 cases of hardware removal due to discomfort. At last follow-up, consolidation was systematic. Reduction was more difficult with longer time to surgery and greater initial displacement. Posterior transiliac plating provided immediately effective fixation in vertically unstable pelvic fracture.

Iliac screw for reconstructing posterior pelvic ring in Tile type C1 pelvic fractures

BACKGROUND

It is often difficult to achieve stable fixation in Tile type C1 pelvic fractures and there is no standard fixation technique for these types of injuries.

HYPOTHESIS

Iliac screw fixation can be used for treating Type C1 pelvic fractures.

PATIENTS AND METHODS

A retrospective review was performed on 47 patients who underwent iliac screw fixation in posterior column of ilium (PCI) for Tile type C1 pelvic fractures from July 2007 to December 2014. All patients were treated with fracture reduction, sacral nerve root decompression (if needed), internal fixation by iliac screw and connecting rod. The data on surgical time, intraoperative bleeding volume, postoperative neurologic functions and postoperative complications were analyzed. Patients were follow-up for at least 12months.

RESULTS

The mean surgical time was 148minutes, and the mean intraoperative bleeding volume was 763ml. Patients were encouraged in-bed activities immediately after surgery. The postoperative Majeed functional score was 48-100 points (mean 80.2), corresponding to an excellent and good recovery of 91.5%. Postoperative X-radiographs and CT scans indicated satisfactory fracture reduction.

DISCUSSION

Iliac screw fixation combined with sacral nerve canal decompression could effectively restore pelvic alignment and improve neurological functions for complex pelvic trauma.

Minimal Access Fixation of Longitudinal Sacral Fractures: The Posterior Internal Fixator with a Minimum of Three Years of Follow-Up

OBJECTIVE

It is a novel choice to have reduction and internal fixation for sacral fracture with iliac screws starting around the posterior superior iliac spine and percutaneously interconnected.

METHODS

This prospective work was performed at Ain Shams University Hospitals, Cairo, Egypt, during the period from January 2013 until January 2016. Fifty consecutive cases of longitudinal fractures of the sacrum were treated surgically using ileoileal fixation via minimal-access surgery.

RESULTS

According to Pohlemann clinical score, 42 patients (84%) were rated to have excellent clinical result, 6 patients (12%) had a good clinical result, and 2 patients (4%) had a fair clinical result. Regarding social scoring, 34 patients returned back to their jobs with the same level of effort and recreational activities (68%). Ten patients returned to work but with changes in their capabilities and decreases in recreational activities (20%). Six patients changed their profession to another one that required less effort (12%). Regarding radiologic scores, 15 patients (30%) had maximum radiologic scoring (excellent), 30 patients (60%) had good, and 5 patients (10%) had fair reduction. In total, 33 patients (66%) had an excellent final result (10/10); 9 patients (18%) had a good final result (9/10), and 8 patients (16%) had a fair result (7-8/10).

CONCLUSIONS

Fractures of the sacrum are challenging injuries regarding methods of fixation, choice of surgical approach, and the possibility of postoperative complications. Minimal-access ileoileal fixation provides a safe, rapid, and easy method for the fixation of such fractures. It is suitable for critical patients, as it is fast and performed with minimal blood loss. Also, because it does not require an image intensifier, it can be used in least-equipped situations, such as in war scenarios.

Percutaneous posterior fixation for unstable pelvic ring fractures

Several posterior fixation techniques for unstable pelvic ring fractures have been described. Here, we present a minimally invasive, percutaneous technique to fix the two posterior iliac crests using spinal instrumentation. Between September 2008 and March 2012, 11 patients with a mean age of 36.4 years were operated because of a vertically unstable Tile C pelvic ring fracture. Posterior fixation was performed using two polyaxial screws in each iliac crest with two subfascial connector rods. At the final follow-up, all patients were evaluated clinically and radiologically. The mean surgery time was 45 minutes; there were no intraoperative complications. At a mean follow-up of four years, the functional Majeed score was excellent in eight patients and good in three patients. The radiological results were excellent in eight patients and good in three patients. Percutaneous posterior fixation of vertically unstable pelvic fractures leads to good functional and radiological outcomes.

TYPE OF STUDY

Technical note, retrospective.

LEVEL OF EVIDENCE

IV.

Percutaneous screw fixation of the iliosacral joint: A case-based preoperative planning approach reduces operating time and radiation exposure

INTRODUCTION

A preoperative planning approach for percutaneous screw fixation of the iliosacral joint provides specific entry points (EPs) and aiming points (APs) of intraosseous screw pathways (as defined by CT scans) for lateral fluoroscopic projections used intraoperatively. The potential to achieve the recommended EPs and APs, to obtain an ideal screw position (perpendicular to the iliosacral joint), to avoid occurrence of extraosseous screw misplacement, to reduce the operating time and the radiation exposure by utilizing this planning approach have not been described yet.

METHODS

On preoperative CT scans of eight human cadaveric specimen individual EPs and APs were identified and transferred to the lateral fluoroscopic projection using a coordinate system with the zero-point in the center of the posterior cortex of the S1 vertebral body (x-axis parallel to upper S1 endplate). Distances were expressed in relation to the anteroposterior distance of the S1 upper endplate (in%). In each specimen on one side a screw was placed with provided EP and AP (New Technique) whereas at the contralateral side a screw was placed without given EP and AP (Conventional Technique). Both techniques were compared using postoperative CT scans to assess distances between predefined EPs and APs and the actually obtained EPs and APs, screw angulations in relation to the iliosacral joint in coronal and axial planes and the occurrence of any extraosseous screw misplacement. The "operating time (OT)" and the "time under fluoroscopy (TUF)" were recorded. Statistical analysis was performed by the Wilcoxon signed-rank test.

RESULTS

EPs were realized significantly more accurate using the new technique in vertical direction. The screw positions in relation to the iliosacral joint showed no significant difference between both techniques. Both techniques had one aberrantly placed screw outside the safe corridor. The (mean±SD) "OT" and the (mean±SD) "TUF" were significantly decreased using the new technique compared to the conventional technique (OT: 7.6±2min versus 13.1±5.8min, p=0.012; TUF: 1.5±0.8min versus 2.2±1.1min).

CONCLUSION

The presented preoperative planning approach increases the accuracy in percutaneous screw fixation of the iliosacral joint, reduces operating time and minimizes radiation exposure to patient and staff.

Open reduction internal fixation versus percutaneous iliosacral screw fixation for unstable posterior pelvic ring disruptions

BACKGROUND

Surgical stabilization of posterior pelvic ring fractures can be achieved by either open or closed methods. They all provide a comparable biomechanical stability. The aim of the present study is to compare the clinical results of both techniques for treating posterior pelvic ring injuries.

MATERIAL AND METHODS

Seventy patients operated for unstable posterior pelvic ring disruptions were retrospectively reviewed. We compared 35 patients treated by open reduction internal fixation (ORIF group) versus 35 patients stabilized by using closed reduction and percutaneous iliosacral screw fixation (CRIF group) under fluoroscopic guidance.

RESULTS

According to pelvic outcome scoring system of Pohlemann et al., 28 patients out of the ORIF group obtained good or excellent results (20 excellent and 8 good), five fair and two poor. In the CRIF group, 30 patients obtained good or excellent results (25 excellent and 5 good), four fair and one poor (P=0.64). The average intraoperative blood loss in the ORIF group was 500cc with average blood transfusion of 2units (1000cc) compared to blood loss 150cc in the CRIF group, with average blood transfusion of 1unit (500cc) (P=0.002). No intraoperative complications were reported in the ORIF group while operative guide wires were broken in two cases in the CRIF group (P=0.16). There were no neurological complications observed in the ORIF group, but one radiculopathy (L5 root palsy) occurred in the CRIF group (P=0.317). In the ORIF group, three patients had superficial wound infection and one patient had deep infection while in the CRIF group, we noted only one case of deep infection (P=0.083).

CONCLUSION

No difference was noticed between ORIF and CRIF. The technical decision is variable according to time of surgery, fracture types, patient general condition, skin condition, presence of ipsilateral fractures of the acetabulum and feasibility of the closed reduction. More studies are needed to identify prognostic factors related to quality of the reduction. We need for creation of decisional algorithm for ORIF versus CRIF.

LEVEL OF EVIDENCE

Level 4.

Internal fixation of S1-S3 iliosacral screws and pubic screw as the best configuration for unstable pelvic fracture with unilateral vertical sacral fracture (AO type C1.3)

BACKGROUND

Although internal fixation is the definitive treatment in unstable pelvic fractures with disruption of the anterior arch and a vertical fracture of the sacrum (AO type C1.3), there have been no agreement of the best technique of internal fixation yet. We aimed to derive comparable objective data on stiffness and load to failure in this type of fracture fixations.

METHODS

Synbone was modified into AO type C1.3 fracture model, while treatments were divided into six internal fixation treatment groups using tension band plate (TBP), symphysis pubis plate (SP) with iliosacral screw at S1 and S2 (IS S1-S2), pubic screw (PS) with iliosacral TBP, PS and IS S1-S2, SP and IS S1-S3, PS and S1-S3 and finally PS and IS S1-S3. Sensor was applied to detect the shifting and rotation of fracture fragments. Mechanical strength test conducted with the application of axial force on the sacrum vertebra (S1).

RESULTS

The highest translational stiffness was observed in the group IS S1-S3 + PS (830.36 N/mm, p = 0.031) and there was no difference on the rigidity of the rotation between the groups posterior fixation using IS S1-S2 and IS S1-S3 ( p = 0.51). Meanwhile the highest load to failure was found in group IS S1-S3 + PS (1522.20 N). PS provided advantages compared to the use of plate.

CONCLUSIONS

Group of PS and S1-S3 IS is the configuration of internal fixation with best translational and rotational stiffness and the largest load to failure compared to other techniques in AO type C1.3 fracture.

Does Lumbopelvic Fixation Add Stability? A Cadaveric Biomechanical Analysis of an Unstable Pelvic Fracture Model

OBJECTIVE

We sought to determine the role of lumbopelvic fixation (LPF) in the treatment of zone II sacral fractures with varying levels of sacral comminution combined with anterior pelvic ring (PR) instability. We also sought to determine the proximal extent of LPF necessary for adequate stabilization and the role of LPF in complex sacral fractures when only 1 transiliac-transsacral (TI-TS) screw is feasible.

MATERIALS AND METHODS

Fifteen L4 to pelvis fresh-frozen cadaveric specimens were tested intact in flexion-extension (FE) and axial rotation (AR) in a bilateral stance gliding hip model. Two comminution severities were simulated through the sacral foramen using an oscillating saw, with either a single vertical fracture (small gap, 1 mm) or 2 vertical fractures 10 mm apart with the intermediary bone removed (large gap). We assessed sacral fracture zone (SZ), PR, and total lumbopelvic (TL) stability during FE and AR. The following variables were tested: (1) presence of transverse cross-connector, (2) presence of anterior plate, (3) extent of LPF (L4 vs. L5), (4) fracture gap size (small vs. large), (5) number of TI-TS screws (1 vs. 2).

RESULTS

The transverse cross-connector and anterior plate significantly increased PR stability during AR (P = 0.02 and P = 0.01, respectively). Increased sacral comminution significantly affected SZ stability during FE (P = 0.01). Two versus 1 TI-TS screw in a large-gap model significantly affected TL stability (P = 0.04) and trended toward increased SZ stabilization during FE (P = 0.08). Addition of LPF (L4 and L5) significantly improved SZ and TL stability during AR and FE (P < 0.05). LPF in combination with TI-TS screws resulted in the least amount of motion across all 3 zones (SZ, PR, and TL) compared with all other constructs in both small-gap and large-gap models.

CONCLUSIONS

The role of LPF in the treatment of complex sacral fractures is supported, especially in the setting of sacral comminution. LPF with proximal fixation at L4 in a hybrid approach might be needed in highly comminuted cases and when only 1 TI-TS screw is feasible to obtain maximum biomechanical support across the fracture zone.

Biomechanical study of four kinds of percutaneous screw fixation in two types of unilateral sacroiliac joint dislocation: a finite element analysis

OBJECTIVE

To compare the biomechanical stability of four different kinds of percutaneous screw fixation in two types of unilateral sacroiliac joint dislocation.

METHODS

Finite element models of unstable Tile type B and type C pelvic ring injuries were created in this study. Modelling was based on fixation with a single S1 screw (S1-1), single S2 screw (S2-1), two S1 screws (S1-2) and a combination of a single S1 and a single S2 screw (S1–S2). The biomechanical test of two types of pelvic instability (rotational or vertical) with four types of percutaneous fixation were compared. Displacement, flexion and lateral bend (in bilateral stance) were recorded and analyzed.

RESULTS

Maximal inferior translation (displacement) was found in the S2-1 group in type B and C dislocations which were 1.58 mm and 1.90 mm, respectively. Maximal flexion was found in the S2-1 group in type B and C dislocations which were 1.55° and 1.95°, respectively. The results show that the flexion from most significant angulation to least is S2-1, S1-1, S1-2, and S1–S2 in type B and C dislocations. All the fixations have minimal lateral bend.

CONCLUSION

Our findings suggest single screw S1 fixation should be adequate fixation for a type B dislocation. For type C dislocations, one might consider a two screw construct (S1–S2) to give added biomechanical stability if clinically indicated.

Sacroiliac screw fixation: A mini review of surgical technique

The sacral percutaneous fixation has many advantages but can be associated with a significant exposure to X-ray radiation. Currently, sacroiliac screw fixation represents the only minimally invasive technique to stabilize the posterior pelvic ring. It is a technique that should be used by experienced surgeons. We present a practical review of important aspects of this technique.

Sacro-iliac joint arthroscopy for arthrodesis after traumatic dislocation. Cadaver and clinical feasibility study

BACKGROUND

Sacro-iliac arthrodesis usually requires an extended posterior approach, which is associated with a number of dreaded complications. Here, we assessed the feasibility of arthroscopic exploration of the dislocated sacro-iliac joint.

MATERIALS AND METHODS

In the first step of our study, we used ligament section to induce loss of sacro-iliac joint coaptation in a cadaver. We then studied 5 patients with Tile C pelvic ring injuries. Arthroscopy was used to clear the joint of fibrous tissue and to roughen the bone to subchondral level in order to induce sacro-iliac arthrodesis. In addition, posterior fixation was performed using a hinge system or an ilio-sacral screw.

RESULTS

The cadaver study confirmed the feasibility of sacro-iliac arthroscopy after disruption of the strong posterior inter-osseous ligament. In the clinical part of the study in 5 patients with Tile C pelvic ring injuries, arthroscopy allowed direct visualisation extending to the anterior part of the joint space. A power burr and synovial knife were introduced to remove the interposed fibrous tissue and to roughen the bone to subchondral level in order to induce joint fusion. In addition, percutaneous or open posterior fixation was performed in all 5 patients. No infectious complications were recorded.

DISCUSSION

An arthroscope cannot be introduced into the normal sacro-iliac joint. In contrast, after traumatic sacro-iliac dislocation, arthroscopy can be used to evaluate the intra-articular injuries and to roughen the bone to subchondral level.

The influence of sacral morphology on the existence of secure S1 and S2 transverse bone corridors for iliosacroiliac screw fixation

Sacroiliac (SI) screw fixation for unstable pelvic fractures stands out as the only minimally invasive method among all other ORIF procedures. A strictly transverse screw trajectory is needed for central or bilateral fracture patterns up to a complete iliosacroiliac fixation. However, secure screw insertion is aggravated by a narrow sacroiliac bone stock. This study investigates the influence of a highly variable sacral morphology to the existence of S1 and S2 transverse corridors. The analysis contained in this study is based on 125 CT datasets of intact human pelvises. First, sacral dysplasia was identified using the "lateral sacral triangle" method in a lateral 3-D semi-transparent pelvic view. Second, 3-D corridors for a 7.3mm screw in the upper two sacral levels were visualised using a proprietary IT workflow of custom-made programme scripts based on the Amira(®)-software. Shape-describing measurement variables were calculated as output variables. The results show a significant linear correlation between ratioT and the screw-limiting S1 isthmus height (Pearson coefficient of 0.84). A boundary ratio of 1.5 represented a positive predictive value of 96% for the existence of a transverse S1-corridor for at least one 7.3mm screw. In 100 out of 125 pelvises (80%), a sufficient S1 corridor existed, whereas in 124 specimens (99%), an S2 corridor was found. Statistics revealed significantly larger S1 and S2 corridors in males compared to females (p<0.05). However, no gender-related differences were observed for clinically relevant numbers of up to 3 screws in S1 and 1 screw in S2. The expanse of the S1 corridor is highly influenced by the dimensions of the dysplastic elevated upper sacrum, whereas the S2 corridor is not affected. Hence, in dysplastic pelvises, sacroiliac screw insertion should be recommended into the 2nd sacral segment. Our IT workflow for the automatic computation of 3-D corridors may assist in surgical pre-operative planning. Furthermore, the workflow could be implemented in computer-assisted surgery applications involving pelvic trauma.

Personalized image-based templates for iliosacral screw insertions: a pilot study

BACKGROUND

Stabilization of rare unstable pelvic fractures in the case of sacral fractures and iliosacral joint dislocations can be tricky. 3D reconstruction and reverse engineering templates may be used to increase the accuracy of screw placement.

METHODS

Computed tomography (CT) images were used to design the template for 16 consecutive patients with unstable pelvic ring fractures, which were used to guide the screw placement. Another 10 patients received screw placement under conventional fluoroscopy. The screw position, radiation exposure, and surgery time were compared between the two groups.

RESULTS

Personalized image-based templates had better correct screw positions (P < 0.05), reduced radiation exposure (P < 0.01), and shorter surgery time (P < 0.05) compared with the conventional group.

CONCLUSIONS

Personalized image-based templates for iliosacral screw insertions can increase the sacral lag screw placement accuracy, reduce radiation exposure, and shorten surgery time compared with traditional fluoroscopic methods.

Biomechanical aspects of pelvic ring reconstruction techniques: Evidence today

Despite the remarkable advances achieved within the boundaries of the new discipline of Pelvic surgery, pelvic ring disruptions remain challenging and complex problems in orthopaedics. The long-term complications related to reconstruction techniques of these injuries have motivated researchers and surgeons to explore various alternative treatment modalities. Several biomechanical studies have addressed these issues. We performed a medline search including studies published during the last 30 years. Our search yielded 114 studies, 39 of which met the pre-specified inclusion criteria and were further critically analysed and discussed regarding the biomechanical aspects of pelvic ring reconstruction techniques. Based on observational approach and evaluation of the studies specific keypoints are highlighted comprising the clinical translation of the biomechanical supported findings.