Internal fixation of unstable pelvic ring injuries

Computer-assisted preoperative planning of bone fracture fixation surgery: A state-of-the-art review

Background: Bone fracture fixation surgery is one of the most commonly performed surgical procedures in the orthopedic field. However, fracture healing complications occur frequently, and the choice of the most optimal surgical approach often remains challenging. In the last years, computational tools have been developed with the aim to assist preoperative planning procedures of bone fracture fixation surgery. Objectives: The aims of this review are 1) to provide a comprehensive overview of the state-of-the-art in computer-assisted preoperative planning of bone fracture fixation surgery, 2) to assess the clinical feasibility of the existing virtual planning approaches, and 3) to assess their clinical efficacy in terms of clinical outcomes as compared to conventional planning methods. Methods: A literature search was performed in the MEDLINE-PubMed, Ovid-EMBASE, Ovid-EMCARE, Web of Science, and Cochrane libraries to identify articles reporting on the clinical use of computer-assisted preoperative planning of bone fracture fixation. Results: 79 articles were included to provide an overview of the state-of-the art in virtual planning. While patient-specific geometrical model construction, virtual bone fracture reduction, and virtual fixation planning are routinely applied in virtual planning, biomechanical analysis is rarely included in the planning framework. 21 of the included studies were used to assess the feasibility and efficacy of computer-assisted planning methods. The reported total mean planning duration ranged from 22 to 258 min in different studies. Computer-assisted planning resulted in reduced operation time (Standardized Mean Difference (SMD): -2.19; 95% Confidence Interval (CI): -2.87, -1.50), less blood loss (SMD: -1.99; 95% CI: -2.75, -1.24), decreased frequency of fluoroscopy (SMD: -2.18; 95% CI: -2.74, -1.61), shortened fracture healing times (SMD: -0.51; 95% CI: -0.97, -0.05) and less postoperative complications (Risk Ratio (RR): 0.64, 95% CI: 0.46, 0.90). No significant differences were found in hospitalization duration. Some studies reported improvements in reduction quality and functional outcomes but these results were not pooled for meta-analysis, since the reported outcome measures were too heterogeneous. Conclusion: Current computer-assisted planning approaches are feasible to be used in clinical practice and have been shown to improve clinical outcomes. Including biomechanical analysis into the framework has the potential to further improve clinical outcome.

Surgical management of paediatric pelvic fractures: a prospective case series and early experience from a level one Egyptian trauma centre

PURPOSE

We aimed to report our early experience treating paediatric pelvic fractures (PPF) surgically, reporting on indications, outcomes, and complications.

METHODS

Patients aged 0-15 with PPF treated surgically at a level I trauma centre were included prospectively between 2016 and 2018. Fractures were classified according to AO/OTA classification system. Functional evaluation was performed using a modification of the Majeed functional scoring system. Radiological evaluation of vertical and posterior displacement was performed according to Matta and Tornetta criteria and the method described by Keshishyan et al. for assessing pelvic rotational asymmetry.

RESULTS

We included 45 patients (77.8% males and 22.2% females), with a mean age of 9.53 ± 3.63 and 19.87 ± 8.84 months of mean follow-up. The functional outcome was excellent in 42 (93.3%) patients, good in two (4.4%), and fair in one (2.2%). Radiologically, the vertical displacement improved from 5.91 ± 4.64 to 3.72 ± 2.87 mm (p-value 0.065), the posterior displacement improved from 7.87 ± 8.18 to 5.33 ± 13.4 mm (p-value 0.031), and the symphyseal diastasis improved from 9.88 ± 7.51 mm to 7.68 ± 3.18 mm (p-value 0.071). Residual pelvic asymmetry improved from 1.2 ± 0.61 to 0.8 ± 0.7 (p-value 0.001). Complications occurred in 21 (46.7%) patients, 11 (24.4%) pin tract infection, six (13.3%) limb length discrepancy, two (4.4%) prominent metals, one (2.2%) subcutaneous haematoma, one (2.2%) infected ISS.

CONCLUSIONS

We achieved acceptable functional and radiological outcomes after surgically treating a group of patients with PPF, which was relatively safe with minimal complications. The proper approach and fracture fixation tool should be tailored according to the fracture classification and the presence of associated injuries.

Biomechanical Comparison of 4 Transsacral Fixation Constructs in a Type 61C, Zone II Pelvic Fracture Model

OBJECTIVES

OTA/AO 61C pelvic ring injuries are vertically unstable because of complete sacral fractures combined with anterior ring injury. The objective of this study was to compare the biomechanical characteristics of 4 transsacral screw constructs for posterior pelvic ring fixation, including one that uses a novel fixation method with a pair of locked washers with interdigitating cams.

METHODS

Type C pelvic ring disruptions were created on 16 synthetic pelvis models. Each pelvis was fixated with an S2 screw in addition to being allocated to 1 of 4 transsacral constructs through S1: (1) 8.0-mm screw, (2) 8.0-mm bolt, (3) 8.0-mm screw locked with a nut, and (4) 8.00-mm screw locked with a nut with the addition of interdigitating washers between the screw head and ilium on the near cortex, and ilium and nut on the far cortex. The anterior ring fractures were not stabilized. Each pelvis underwent 100,000 cycles at 250 N and was then loaded to failure using a unilateral stance testing model. The anterior and posterior osteotomy sites were instrumented with pairs of infrared (IR) light-emitting markers, and the relative displacement of the markers was monitored using a three-dimensional (3D) motion capture system. Displacement measurements at 25,000; 50,000; 75,000; and 100,000 cycles and failure force were recorded for each pelvis.

RESULTS

The novel washer design construct performed better than the screw construct with less posterior ring motion at 75,000 ( P = 0.029) and 100,000 cycles ( P = 0.029).

CONCLUSIONS

The novel interdigitating washer design may be superior to using a screw construct alone to achieve rigid, locked posterior ring fixation in a synthetic pelvis model with a Type C pelvic ring disruption.

Analysis of Postoperative Gait, Hip Strength, and Patient-Reported Outcomes After OTA/AO 61-B and 61-C Pelvic Ring Injuries

OBJECTIVES

To examine clinical gait parameters, hip muscle strength, pelvic functional outcomes, and psychological outcomes after surgical fixation of OTA/AO 61-B and 61-C pelvic ring injuries.

DESIGN

Retrospective review identified 10 OTA/AO 61-B patients and 9 OTA/AO 61-C patients for recruitment who were between 1 and 5 years after pelvic fixation. Gait and strength assessments, and patient-reported outcome scores were performed/collected and analyzed.

SETTING

Outpatient clinical motion performance laboratory.

PATIENTS/PARTICIPANTS

Patients with OTA/AO 61-B and OTA/AO 61-C fractures who were between 1 and 5 years after pelvic fixation.

MAIN OUTCOME MEASUREMENTS

Hip strength, kinetics, and spatial-temporal outcomes; Majeed Pelvic Outcome Score; Short Form 36; Hamilton Anxiety/Depression Rating Scales.

RESULTS

There were no differences in age, body mass index, or time since definitive fixation between OTA/AO 61-B and 61-C groups. The OTA/AO 61-C group had higher median injury severity scores, longer length of stay, and greater postoperative pelvic fracture displacement. There was no difference in bilateral hip strength, bilateral peak hip moments, peak hip power, and walking speed between groups. Patients with OTA/AO 61-C fractures had lower scores on Short Form 36 General Health and Majeed Work, with a trend toward a lower Total Majeed score. There were no differences in self-reported total anxiety and depression symptoms.

CONCLUSIONS

This study did not identify any gait, strength, or psychological differences between OTA/AO 61-B and 61-C injuries at 1-5 years of follow-up. However, increased injury severity in OTA/AO 61-C patients may have residual consequences on perceived general health and ability to work. This pilot study establishes a template for future research into functional recovery of patients with severe pelvic ring trauma.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Lateral Compression Type 2 Pelvic Fractures-A Clinical Study of Fracture Displacement Measurement and Closed Reduction

Objective

To evaluate the displacement in four lateral compression type 2 (LC2) fracture subtypes (iliac wing and three kinds of crescent fractures) and to investigate the appropriate closed reduction for treatment using a pelvic reduction frame.

Methods

A total of 71 patients with LC2 pelvic fractures from February 2014 to November 2019 were included in this retrospective cohort study. Preoperative X‐ray and computed tomography data were used to assess the direction of the fracture displacement and the sacroiliac joint dislocation. The fractures in all patients were reduced with a pelvic reduction frame and fixed with percutaneous screws as well as an anterior subcutaneous pelvic ring internal fixator. Two different closed reduction strategies were adopted, one was first longitudinal traction and then transverse traction, the other was first transverse traction then longitudinal and LC2 traction. The Matta score system was used to evaluate the postoperative X‐ray and the Majeed score system was used for follow‐up evaluation.

Results

A total of 13 iliac wing fractures (86.7%) and 16 Day type 1 fractures (94.1%) were vertically stable with only internal displacement, the ring width displacements were 5 (3, 8.75) and 8 (4, 12) mm, the posterior superior iliac spine (PSIS) differences were 0 (0, 0) mm and 0 (0, 0) mm. A total of 21 Day type 2 fractures (95.5%) and 16 Day type 3 fractures (94.1%) were characterized by cephalic and dorsal fracture dislocation on the basis of internal displacement, the ring width displacements were 6 (4.25, 12) and 4 (0, 7.5) mm and the PSIS differences were 4 (2, 5) and 0 (0, 3.75) mm. Based on the Matta scores, excellent reduction was achieved in 51 patients, good reduction in 17 patients, and poor reduction in three patients. The average Majeed score was 91.6, with a minimum outpatient follow‐up of 12 months (average 31.6 months).

Conclusion

LC2 fractures involve two different kinds of fracture displacement: internal displacement only and a combination of internal, cephalic, and dorsal dislocation through the sacroiliac joint. Good clinical outcomes can be achieved for LC2 fractures using two different closed reduction strategies.

Trans-sacral screw fixation of posterior pelvic ring injuries: review and expert opinion

Posterior pelvic ring injuries (i.e., sacro-iliac joint dislocations, fracture-dislocations, sacral fractures, pelvic non-unions/malunions) are challenging injury patterns which require a significant level of surgical training and technical expertise. The modality of surgical management depends on the specific injury patterns, including the specific bony fracture pattern, ilio-sacral joint involvement, and the soft tissue injury pattern. The workhorse for posterior pelvic ring stabilization has been cannulated iliosacral screws, however, trans-sacral screws may impart increased fixation strength. Depending on injury pattern and sacral anatomy, trans-sacral screws can potentially be more beneficial than iliosacral screws. In this article, the authors will briefly review pelvic mechanics and discuss their rationale for ilio-sacral and/or trans-sacral screw fixation.

A Morphologic Analysis of the Pubic Symphysis Using CT and MRI

INTRODUCTION

The goal of this study was to investigate prevalence and morphometric parameters of pubic ligaments and the interpubic disk and its cavity using imaging methods for use in clinical medicine.

METHODS

Pubic symphysis morphology was investigated in 652 patients (348 women and 304 men), from which 449 CT scans and 203 MR scans were available. The average age of men was 48 years and women 39 years. Investigated parameters included dimensions of the interpubic disk, visibility and width of the reinforcing ligaments, and visibility, dimensions, and location of the symphysial cavity. The results were compared with MR scans of 20 healthy volunteers and 21 dissected anatomic specimens.

RESULTS

The craniocaudal, ventrodorsal, and mediolateral diameters of the pubic disk were 36 to 37.7, 14.8 to 15.2, and 2.2 to 4.2 mm in women and 42 to 42.3, 18.6 to 19, and 2.4 to 4.5 mm in men, respectively. Higher age correlated with shorter mediolateral diameter and larger craniocaudal and ventrodorsal diameters. The superior pubic ligament was visible in 93.1% of men (1.44 mm thick) and in 100% of women (1.7 mm); the inferior pubic ligament in 89.7% of men (1.74 mm) and 88% of women (1.95 mm), the anterior pubic ligament in 96.6% of men (1.5 mm) and 82% of women (1.34 mm); and the posterior pubic ligament in 65.5% of men (1.18 mm) and 63.7% of women (0.83 mm). A symphysial cavity was found in 24% of men and 22.9% of women, with craniocaudal, ventrodorsal, and mediolateral dimensions of 13, 10.7, and 3.2 mm in men and 9.5, 10.7, and 3 mm in women, respectively.

CONCLUSION

The presented morphologic parameters provide an anatomic reference for diagnostics of pathologic conditions of the pubic symphysis. The following anatomic structures should be added to the official anatomic terminology: symphysial cavity (cavitas symphysialis), retropubic eminence (eminentia retropubica), anterior pubic ligament (ligamentum pubicum anterius), and posterior pubic ligament (ligamentum pubicum posterius).

LEVEL OF EVIDENCE

II-III.

Supraacetabular osseous corridor: defining dimensions, sex differences, and alternatives

INTRODUCTION

The supraacetabular (SA) corridor extends from the anterior inferior iliac spine to the posterior ilium and can safely accommodate implants to stabilize pelvic and acetabular fractures. However, quantitative analysis of its dimensions and characteristics have not been thoroughly described. This study seeks to define the dimensions, common constriction points, and any alternative trajectories that would maximize the corridor diameter.

METHODS

Computed tomography of 100 male and 100 female hemipelves without osseous trauma were evaluated. The corridor boundaries were determined through manual best-fit analysis. The largest intercortical cylinder within the pathway was created and measured. Alternative trajectories were tested within the SA boundaries to identify another orientation that maximized the diameter of the intercortical cylinder.

RESULTS

The traditional SA corridor had a mean diameter of 8.3 mm in men and 6.2 mm in women. This difference in diameter is due to a more S-shaped ilium in women. A larger alternative SA corridor was found that had a less limited path through the ilium and measured 11.3 mm in men and 9.9 mm in women. These dimensions are significantly different compared to those of the traditional SA corridor in both men and women.

CONCLUSIONS

In men, the SA corridor allows for the safe passage of most hardware used in pelvic and acetabular fractures. However, in women, the SA corridor is restricted by a more S-shaped ilium. An alternative trajectory was found that has a significantly larger mean diameter in both sexes. Ultimately, the trajectory of hardware will be dictated by the clinical scenario. When large implants are needed, especially in women, we recommend considering the alternative SA corridor.

Surgical Treatment of Vertical Shear Pelvic Fracture Associated with a Lumbosacral Plexus Injury through the Lateral-Rectus Approach: Surgical Techniques and Preliminary Outcomes

OBJECTIVE

To examine the surgical techniques and preliminary outcomes of the lateral rectus approach (LRA) for treating vertical shear (VS) pelvic fracture associated with lumbosacral plexus (LSP) injury.

METHODS

This study was a retrospective trial. From August 2010 to October 2017, 29 patients with VS pelvic fractures involving LSP injury who were treated with the LRA were included in this study. The patients were 18-61 years old, with a mean age of 36.2 years. All patients underwent neurolysis, open reduction, and internal fixation (ORIF) through the LRA. The fracture reduction was evaluated using the Matta criteria, and the neural recovery was evaluated by muscle strength grading proposed by the British Medical Research Council (BMRC).

RESULTS

All 29 patients underwent the surgery successfully. The mean operating time was 155.2 ± 32.1 min (range: 105-220 min). The mean operative blood loss was 1021.4 ± 363.4 mL (range: 400-2000 mL). All patients were followed-up for at least 24 months (mean, 32.8 ± 13.5 months; range: 24-96 months). According to the Matta criteria, there were 17 excellent cases, nine good cases, and three fair cases in 29 patients. The ratio of excellent-to-good cases was 89.66%. According to the criteria of the Nerve Injuries Committee of the British Medical Research Council (BMRC), the recovery of nerve and muscle strength achieved to M5 (full recovery of neurological symptoms) was 14 cases, M4 (fine recovery of neurological symptoms), seven cases; M1, M2, and M3 (partial recovery of neurological symptoms), five cases, and M0 (no recovery of neurological symptoms), three cases.

CONCLUSIONS

LRA is a safe and feasible surgical approach for treating VS pelvic fractures with LSP injury, which can be used to perform nerve exploration and release from the front, reduce the fracture, and fix it with the anterior iliac plates and/or sacroiliac screws.

Percutaneous screw fixation assisted by hollow pedicle finder for superior pubic ramus fractures

Background

Pubic ramus fracture was an injury of anterior pelvic ring, the anterior pelvic ring plays an important role in maintaining the stability of the pelvis. The purpose of this study was to investigate the effect and indication of percutaneous retrograde pubic screw fixation assisted by hollow pedicle finder for pubic ramus fractures.

Methods

The clinical data of 68 patients with pubic ramus fracture treated with cannulated screw from March 2008 to March 2020 were retrospectively analyzed. According to the surgical methods, they were divided into traditional surgery group (32 cases in group A, with traditional retrograde pubic screw fixation) and modified surgery group (36 cases in group B, with percutaneous retrograde pubic screw fixation assisted by hollow open circuit device). Operation time, blood loss, incision length, screw length and complications were recorded and compared between the two groups. On the second day after surgery, the maximum fracture displacement over plain radiographs, entrance radiographs and exit radiographs of the pelvis was evaluated according to Matta criteria to evaluate the postoperative fracture reduction. Majeed score was used to evaluate the hip function at 12 months after surgery.

Results

The operations were successfully completed in both groups. The operation time, blood loss and incision length in group B were significantly less than those in group A (P < 0.05). There was no significant difference in screw length between the two groups (t = 0.797, P = 0.431). All patients were followed up for 8–38 months (mean 21.8 months). There were no vascular and nerve injury, fracture of internal fixator, screw entry into joint cavity, fracture nonunion and other complications in both groups. The fracture healing time of the two groups was 23.1 ± 2.1 weeks in group A while 22.7 ± 2.1 weeks in group B, respectively, and there was no statistical difference in the fracture healing time between the two groups (P > 0.05). In group A, there were 3 cases of incision infection, 1 case of incision fat liquefaction and 2 cases of lower extremity deep venous thrombosis, and the complication rate was 18.8%. There was only 1 case of lower extremity deep vein thrombosis in group B, and the complication rate was 2.8%, which was significantly lower than that in group A. The fracture in one case after surgery was found to be displaced in group A and no fracture was found in group B. There was no significant difference between the two groups in Matta imaging evaluation on the next day after surgery and Majeed function evaluation at 12 months after surgery (P > 0.05).

Conclusion

Percutaneous retrograde pubic ramus screw fixation assisted by hollow pedicle finder is effective in the treatment of pelvic pubic ramus fracture. It has the advantages of less incision, shorter operation time, less blood loss and lower incidence of complications compared with traditional methods. However, correct surgical indications should be required when we apply this surgical method.

Computer-aided automatic planning and biomechanical analysis of a novel arc screw for pelvic fracture internal fixation

BACKGROUND AND OBJECTIVE

The sacroiliac joint screw is a common fixation method for pelvic posterior ring fractures. The complex anatomical structure around the pelvis makes it impossible to find a suitable fixed path, which increases the difficulty of surgical operation. In this paper, we propose an automatic planning algorithm based on a computer-aided internal arc fixation channel for pelvic fractures for the first time.

METHODS

A channel generation algorithm based on seed derived points was designed, and the optimal channel was selected by scoring rules based on 3D erode algorithm for the generated channel. The biomechanical properties of the internal arc fixation screw and traditional internal straight fixation screw in three postures were compared using biomechanical finite element analysis.

RESULTS

The proposed algorithm verified the existence of a more adaptable internal arc fixation channel and can quantitatively plan a relatively optimal constant-curvature internal arc fixation channel in pelvises of ten adults. Significantly high stresses concentrated around the interaction region between the screws and bone may increase the risk of bone fractures and screw loosening in the long term. The experimental results show that the internal arc fixation screw has better strain and deformation performance than the internal straight fixation screw.

CONCLUSIONS

A novel arc internal fixation method for pelvic fractures was proposed to improve the safety and stability of screw fixation of pelvic fracture. The nonparametric test proved that the sacroiliac dislocation model repaired by internal arc fixation screw was significantly different from that repaired by internal straight fixation screw. The computer-aided automatic planning algorithm provides the possibility of robot-assisted pelvic fracture fixation.

A clinical and biomechanical comparison of INFIX plus single versus double sacroiliac screw fixation for unstable pelvic ring injury

BACKGROUND

The aim of this study is to compare the clinical and biomechanical outcome of INFIX plus single with two sacroiliac screw fixation for unstable pelvic fractures of Type C.

METHODS

Sixteen cadavers were randomly subjected to INFIX plus single or double sacroiliac screw fixations and then mounted onto the ElectroForce loading machine under different vertical loads. To investigate the clinical outcomes of the two techniques, nineteen patients were retrospectively analyzed. The main outcome measures were postoperative radiographic reduction grading (using the Tornetta and Matta grading system), functional outcome (using the Majeed scoring system), and incidence of complications.

RESULTS

In the biomechanical study, INFIX plus double sacroiliac screw fixation showed better biomechanical stability than fixation with a single sacroiliac screw (p < 0.05). In our clinical case series, all 19 patients had bony union 6 months after the operation. INFIX plus double sacroiliac screw fixation also demonstrated a better functional outcome and a higher radiographic satisfactory rate than INFIX plus single sacroiliac screw fixation (79.25 ± 5.47; 91.33 ± 4.97; p < 0.05), (77.78% vs. 60%; p = 0.05). One patient in INFIX plus single-screw fixation group had screw loosening at 6-month follow-up postoperatively. One case in each group suffered heterotopic ossification and the lateral femoral cutaneous nerve paralysis, and one patient suffered from infection.

CONCLUSION

INFIX plus double sacroiliac screw fixation demonstrated more stability in cadaveric biomechanical analysis and better clinical outcomes than INFIX plus single sacroiliac screw fixation.

Morphological Asymmetry of Pelvic Rings: A Study Based on Three-Dimensional Deviation Analysis

OBJECTIVE

To evaluate the morphological asymmetry of pelvic rings existing in healthy individuals in terms of three-dimensional (3D) geometric shapes.

METHODS

This study was a retrospective self-control study. CT images of healthy pelvises, scanned from Jan 2014 to Jan 2019, were taken from 159 subjects (88 males and 71 females) aged 20 to 59 years (39.1 ± 8.7 years). Digital pelvic ring models were reconstructed from CT images and then flipped over the corresponding sagittal planes to obtain their mirrored models. A 3D deviation analysis of a pelvic ring was conducted between the original model and its mirrored model via model registration and quantification of the geometric differences. Next, the pelvic rings were split to the left and right hipbones. The same flipping procedures as done by pelvic rings were performed for left hipbones to obtain their mirrored models. A 3D deviation analysis was also performed between the left and right hip bones. Quantitative variables representing deviation mainly included the average deviation (AD) and the maximum deviation (MD). MDs over 4 mm and 10 mm were deemed as critical levels for evaluating the severity of asymmetry as per Matta's scoring system. The quantitative assessments of the asymmetry covered pelvic rings, bilateral hip bones and the specific anatomic regions of a hip bone.

RESULTS

157 out of 159 pelvic rings (98.74%) had more than 4 mm of the MD and 27 (16.98%) of them exceeded 10 mm of the MD. The MD of pelvic rings was 1.23 times as high as that for the bilateral hip bones (7.46 mm vs. 6.08 mm, P < 0.05). The ADs of pelvic rings and bilateral hip bones were 1.28 mm and 0.94 mm, respectively (P < 0.05); 2.27% of the surface points of a pelvic ring had more than 4 mm geometric deviations compared with its mirrored model, while 0.59% (P < 0.05) of bilateral hip bones were on the same level of deviation. 119 out of 159 pelvic iliac crests (74.8%) had MDs more than 4 mm, and 15 (9.4%) reached 10 mm or more. Only 15 (9.4%) pelvises presented asymmetric features in the area of obturator foramen where the MDs exceeded 4 mm.

CONCLUSIONS

Pelvic asymmetry exists in the general population, but 3D geometric symmetry is present in specific anatomic regions. It implies that restoring the 3D symmetry of specific anatomic regions is more reliable than "restoring the symmetry of pelvic ring" in pelvic ring reduction or pelvic fixation design.

Minimally Invasive Percutaneous TightRope® System Fixation for an Unstable Posterior Pelvic Ring: Clinical Follow-up and Biomechanical Studies

Objective

To evaluate the mechanical stability and clinical efficacy of minimally invasive percutaneous TightRope® systems applied via gun‐shaped reduction forceps for unstable posterior pelvic ring fractures.

Materials and methods

This study consists of two parts: a clinical retrospective study and a randomized controlled biomechanical test. For the clinical study, a retrospective analysis of posterior pelvic ring fractures was performed between June 2015 and May 2020. Eighteen patients underwent surgery using two TightRope® systems to fix a broken posterior pelvic ring because of unstable AO type C1 and C2 pelvic ring fractures. The patients were followed up for at least 2 years, and all patients were evaluated using the Majeed scoring system and vertical displacement. In the biomechanical tests, six embalmed adult pelvic specimens were used. The fractures were subjected to TightRope®, IS screw, and TBP fixation in a randomized block design. The specimens were placed in a biomechanical testing machine in a standing neutral posture. A cyclic vertical load of up to 500 N was applied, and the displacement of the specimens was recorded by the testing machine. The ultimate load in each group of specimens was recorded. The displacement and ultimate load were compared and analyzed by statistical methods.

Results

At a mean follow‐up of 38.89 ± 8.72 months, the functional Majeed score was excellent in 14 patients and good in four patients. The final radiological examinations showed that the outcome was excellent in 14 patients and good in four patients. In these patients, no serious clinical complications were found. Weight‐bearing was delayed in four patients. In biomechanical tests, the displacement of the specimens fixed with TightRope® was significantly lower than that of the specimens fixed with TBP (P < 0.05) when the load ranged from 300 to 500 N. The displacement in the IS screw group was significantly lower than that in either the TBP or TightRope® group (P < 0.05) when the load ranged from 0 to 500 N. The ultimate load in the IS screw group (1798 ± 83.53 N) was significantly greater than that in the TBP group (1352 ± 74.41 N) (t = 9.78, P < 0.0001) and the TightRope® group (1347 ± 54.28 N) (t = 11.11, P < 0.0001). However, no significant difference was observed between the TightRope® and TBP groups (t = 0.13, P = 0.90).

Conclusion

Percutaneous posterior TightRope® system shows strong stability in mechanical experiments and shows good results in clinical follow‐up while this system has certain advantages in lower surgical requirements and lower risk of related nerve and vascular structural damage.

Design and evaluation of an intelligent reduction robot system for the minimally invasive reduction in pelvic fractures

Introduction

Pelvic fracture is a severe high-energy injury with the highest disability and mortality of all fractures. Traditional open surgery is associated with extensive soft tissue damages and many complications. Minimally invasive surgery potentially mitigates the risks of open surgical procedures and is becoming a new standard for pelvic fracture treatment. The accurate reduction has been recognized as the cornerstone of minimally invasive surgery for pelvic fracture. At present, the closed reduction in pelvic fractures is limited by the current sub-optimal 2D intra-operative imaging (fluoroscopy) and by the high forces of soft tissue involved in the fragment manipulation, which might result in fracture malreduction. To overcome these shortcomings and facilitate pelvic fracture reduction, we developed an intelligent robot-assisted fracture reduction (RAFR) system for pelvic fracture.

Methods

The presented method is divided into three parts. The first part is the preparation of 20 pelvic fracture models. In the second part, we offer an automatic reduction algorithm of our robotic reduction system, including Intraoperative real-time 3D navigation, reduction path planning, control and fixation, and robotic-assisted fracture reduction. In the third part, image registration accuracy and fracture reduction accuracy were calculated and analyzed.

Results

All 20 pelvic fracture bone models were reduced by the RAFR system; the mean registration error E1 of the 20 models was 1.29 ± 0.57 mm. The mean reduction error E2 of the 20 models was 2.72 ± 0.82 mm. The global error analysis of registration and reduction results showed that higher errors are mainly located at the edge of the pelvis, such as the iliac wing.

Conclusion

The accuracy of image registration error and fracture reduction error in our study was excellent, which could reach the requirements of the clinical environment. Our study demonstrated the precision and effectiveness of our RAFR system and its applicability and usability in clinical practice, thus paving the way toward robot minimally invasive pelvic fracture surgeries.

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.

Robot-Assisted Autonomous Reduction of a Displaced Pelvic Fracture: A Case Report and Brief Literature Review

Displaced pelvic fracture is among the most complicated fractures in traumatic orthopedics, with high mortality and morbidity. Reduction is considered a complex procedure as well as a key part in surgical treatment. However, few robotic techniques have been employed in the reduction of pelvic fracture, despite the rapid advancement of technologies. Recently, we designed a robot surgery system specialized in the autonomous reduction of displaced pelvic fracture and applied it in the true patient for the first time. In this paper, we report its successful clinical debut in the surgery of a displaced pelvic fracture. Total surgery time was 110 min and an anatomic reduction was achieved. We then present a brief overview of the literature about reduction techniques in pelvic fracture and introduce related principles involved in our robot-assisted reduction system.

Percutaneous two unilateral iliosacral S1 screw fixation for pelvic ring injuries: a retrospective review of 38 patients

Purpose

Percutaneous iliosacral (IS) screw fixation for pelvic ring injuries is a minimally invasive technique that reduces the amount of blood loss and shortens the procedure time. Moreover, two unilateral IS S1 screws exhibit superior stability to a single IS screw and are also safer for neurological injuries than an S2 screw. Therefore, this study aimed to evaluate fixation using percutaneous two unilateral IS S1 screws for pelvic ring injuries and its subsequent clinical outcomes.

Methods

We retrospectively reviewed 38 patients who underwent percutaneous two unilateral IS S1 screw fixation for pelvic ring injuries. The procedure time, blood loss, achievement of bone union, radiological outcomes (Matta and Tornetta grade), and postoperative complications were evaluated.

Results

The mean procedure time, hemoglobin loss, bone union rate, and time to union were 40.1 minutes (range, 18-102 minutes), 0.6 g/dL (range, 0.3-1.0 g/dL), 100%, and 153.2 days (range, 61-327 days), respectively. The Matta and Tornetta grades were excellent, good, and fair in 24 (63.1%), 11 (28.9%), and three patients (7.9%), respectively, and the postoperative complications were S1 screw loosening, widening of the symphysis pubis (2.3 and 2.5 mm), lumbosacral plexopathy, and S1 radiculopathy in one (2.6%), two (5.3%), one (2.6%), and one patient (2.6%), respectively. However, all neurological complications recovered spontaneously.

Conclusions

Percutaneous two unilateral IS S1 screw fixation was useful for treating pelvic ring injuries. In particular, it involved a short procedure time with little blood loss and also led to 100% bone union and good radiological outcomes.

Effect of Percutaneous Posterior Pelvic Ring Reduction and Fixation on Patient-Reported Outcomes

OBJECTIVES

The purpose of this study was to assess patient outcomes using Patient-Reported Outcomes Measurements Information System (PROMIS) scores after closed reduction and percutaneous fixation (CRPF) of the posterior pelvic ring and determine whether quality of reduction affects the outcomes.

DESIGN

This is a retrospective cohort study.

SETTING

The study involved a Level I trauma center.

PATIENTS

The study included 46 adult patients with operatively treated pelvic ring injuries (63% OTA/AO 61-B) who underwent CRPF between 2014 and 2018 at a single institution.

INTERVENTION

The intervention involved closed reduction and percutaneous posterior pelvic ring fixation.

MAIN OUTCOME MEASUREMENTS

The main outcome measurements were postoperative patient PROMIS scores, including physical function, pain interference, anxiety, and depression, and radiographic measurements of postoperative displacement and pelvic deformity.

RESULTS

After CRPF, PROMIS scores of physical function, pain interference, and anxiety were significantly improved at the time of final follow-up when compared with the first postoperative visit. The amount of malreduction or pelvic deformity did not significantly affect outcome scores; however, results were limited by small sample size.

CONCLUSIONS

CRPF of posterior pelvic ring injuries results in good functional and radiographic outcomes. Degree of malreduction may not affect outcomes as much as previously believed.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Accuracy of Radiographic Displacement Measurement in a Pelvic Ring Injury Model

BACKGROUND

Pelvic ring injury outcome studies rely on radiographic assessment. To date, no study investigates the accuracy of radiographic measurement. The aim of this study was to assess the accuracy and interobserver reliability of pelvic ring displacement measurement in an injury model. We hypothesize that current radiographic measurement methods do not accurately quantify the three-dimensional pelvic ring displacement.

METHODS

Ten orthopaedic traumatologists evaluated 12 pelvic ring injury model displacements using AP, inlet, and outlet radiographs and axial CT images. Observers completed a survey of demographic and treatment approach strategies. Radiographic displacement measurements in axial, coronal, and sagittal planes were analyzed for accuracy using. Absolute displacement measurements were categorized with Matta and Tornetta grading system for Fleiss Kappa inter-reliability correlation evaluation.

RESULTS

The mean age of orthopaedic traumatologists was 47.5 years (range 36 to 59) with a mean 15.3 years (range 4 to 27) of pelvic fracture surgery experience. Radiographic measurement of isolated uniplanar of pelvic displacement in axial, sagittal, or coronal plane alone was more accurate than multiplanar pelvic displacements with more than one plane of displacement, 6.6 ± 5.7 mm error compared with 9.6 ± 6.3 mm error, respectively (P = 0.0035). Measurement accuracy was greater with isolated coronal plane (4 ± 3.5 mm error) compared with isolated axial plane (9.9 ± 7.1 mm error) or isolated sagittal plane displacement (6.7 ± 4 mm error). Interrater reliability for the radiographic displacement measurement by observers showed an overall poor agreement with 0.24.

CONCLUSION

Radiographic displacement measurement in these modeled pelvic ring injuries has notable inaccuracy among various measurement methods. Coronal and sagittal plane radiographic displacement measurements are more accurate compared with axial plane measurement. The reporting of radiographic displacement measurement outcomes in clinical research studies should be critically evaluated, and standardization of pelvic ring injury displacement may not be achievable with radiography.

LEVEL OF EVIDENCE

Level V.

S2-Alar-Iliac Screw Fixation versus Iliac Screw Fixation in the Treatment of Sacral Fractures

PURPOSE

To compare the short-term therapeutic effects of S2-alar-iliac (S2AI) screw fixation and iliac screw fixation techniques in managing sacral fractures.

METHODS

From September 2015 to May 2020, 42 patients with sacral fractures who underwent lumbopelvic fixation by a single surgeon were analyzed. The patients were divided into the S2AI screw group (19 patients) and the iliac screw group (23 patients). Operative data, reduction quality, postoperative complications, and functional outcomes were evaluated.

RESULTS

The incidence of unplanned reoperation was significantly different between patients treated with S2AI screws than in those treated with iliac screws (0 versus 6, p = 0.02). The mean intraoperative estimated blood loss was 405.26 ± 229.67 mL in the S2AI screw group and 539.13 ± 246.32 mL in the iliac screw group (P = 0.08). No significant difference was observed in either group regarding the quality of reduction, functional outcome, or low back pain. The reduction quality based on the Matta criteria and excellent/good outcomes were 21/2 in the iliac screw group and 17/2 in the S2AI screw group. The functional outcomes based on the Majeed score and excellent/good/fair outcomes were 17/3/3 in the iliac screw group and 17/1/1 in the S2AI screw group. No complications, including implant breakage, loosening of the implant, or loss of reduction were found in either group during follow-up.

CONCLUSION

Both S2AI screws and iliac screws were effective in the treatment of sacral fractures. The use of S2AI screws, however, was independently associated with fewer unplanned reoperations for surgical site infection, wound dehiscence, and symptoms of screw protrusion than the use of iliac screws.

Comparative efficacy and safety of the minimally invasive ilioinguinal approach for anterior pelvic ring fracture: A protocol for systematic review and network meta-analysis

BACKGROUND

Anterior pelvic ring contributes up to 40% of the stability of the pelvic ring and is located in close proximity to key pelvic organs, blood vessels, and nerves. An anterior pelvic ring fracture causes severe pain and is a potentially life-threatening condition in trauma patients. Currently available surgical repair methods are highly technical and include high risks of complications. The minimally invasive ilioinguinal approach (MIIA) is an emerging technique that reduces the risk of femoral nerve and external iliac vessel injury. However, the safety and efficacy of this technique have yet to be systematically scrutinized. This study outlines a proposed protocol for a network meta-analysis that investigates the efficacy of MIIA for anterior pelvic ring fracture.

METHODS

This study will utilize both Chinese and English language databases. All randomized controlled trials studying the use of MIIA for anterior pelvic ring fracture from January 2016 to May 2021 will be incorporated. Researchers will screen for literature that fits the inclusion criteria, followed by an assessment of risk bias and, finally, data extraction.

RESULTS

The Bayesian network meta-analysis will be used to evaluate all available Stata 14.0 and WinBUGS software.

CONCLUSION

Our research aims to uncover the clinical utility of the MIIA approach for anterior pelvic ring fractures.

ETHICS AND DISSEMINATION

Not required.

INPLASY REGISTRATION NUMBER

INPLASY2021110020.

Does Cement Augmentation of the Sacroiliac Screw Lead to Superior Biomechanical Results for Fixation of the Posterior Pelvic Ring? A Biomechanical Study

Background and Objectives: The stability of the pelvic ring mainly depends on the integrity of its posterior part. Percutaneous sacroiliac (SI) screws are widely implanted as standard of care treatment. The main risk factors for their fixation failure are related to vertical shear or transforaminal sacral fractures. The aim of this study was to compare the biomechanical performance of fixations using one (Group 1) or two (Group 2) standard SI screws versus one SI screw with bone cement augmentation (Group 3). Materials and Methods: Unstable fractures of the pelvic ring (AO/OTA 61-C1.3, FFP IIc) were simulated in 21 artificial pelvises by means of vertical osteotomies in the ipsilateral anterior and posterior pelvic ring. A supra-acetabular external fixator was applied to address the anterior fracture. All specimens were tested under progressively increasing cyclic loading until failure, with monitoring by means of motion tracking. Fracture site displacement and cycles to failure were evaluated. Results: Fracture displacement after 500 cycles was lowest in Group 3 (0.76 cm [0.30] (median [interquartile range, IQR])) followed by Group 1 (1.42 cm, [0.21]) and Group 2 (1.42 cm [1.66]), with significant differences between Groups 1 and 3, p = 0.04. Fracture displacement after 1000 cycles was significantly lower in Group 3 (1.15 cm [0.37]) compared to both Group 1 (2.19 cm [2.39]) and Group 2 (2.23 cm [3.65]), p ≤ 0.04. Cycles to failure (Group 1: 3930 ± 890 (mean ± standard deviation), Group 2: 3676 ± 348, Group 3: 3764 ± 645) did not differ significantly between the groups, p = 0.79. Conclusions: In our biomechanical setup cement augmentation of one SI screw resulted in significantly less displacement compared to the use of one or two SI screws. However, the number of cycles to failure was not significantly different between the groups. Cement augmentation of one SI screw seems to be a useful treatment option for posterior pelvic ring fixation, especially in osteoporotic bone.

Clinical application of anterior ring internal fixator system combined with sacroiliac screw fixation in Tile C pelvic fracture treatment

Background

How to perform minimally invasive surgery for Tile C pelvic fracture is a major problem in clinical practice. We performed minimally invasive surgery for Tile C pelvic fracture using anterior ring internal fixator systems combined with sacroiliac screw fixation.

Objective

To investigate the advantages and efficacy of anterior ring internal fixator systems combined with sacroiliac screw fixation in the treatment of Tile C pelvic fracture.

Methods

From May 2017 to May 2020, 27 patients with Tile C pelvic fracture who underwent anterior ring internal fixator system combined with sacroiliac screw fixation (group A) and 21 patients with Tile C pelvic fracture who underwent plate-screw system combined with sacroiliac screw fixation (group B) were retrospectively analyzed.

Results

All 48 patients were followed up for more than 12 months, all fractures healed within 3–6 months. The operative time, intraoperative bleeding volume, blood transfusion volume, incision length, hospital stay, complication rate and Majeed score were 63.5 ± 10.7 min, 48.3 ± 27.9 ml, 0 ml, 4.5 ± 0.8 cm, 10.2 ± 2.7 d, 3.7% and 89.7 ± 4.6 points, respectively, in group A and 114.8 ± 19.1 min, 375 ± 315.8 ml, 266.7 ± 326.6 ml, 9.2 ± 3.9 cm, 20.9 ± 5.7 d, 23.8% and 88.7 ± 4.9 points, respectively, in group B. Combined excellent and good rates of the Matta evaluation and Majeed score were 100% in both groups. There were no significant differences in the Matta evaluation or Majeed score between the two groups (both P > 0.05), whereas the operative time, intraoperative bleeding volume, blood transfusion volume, incision length and hospital stay were significantly less in group A (all P < 0.05).

Conclusion

An anterior ring internal fixator system combined with sacroiliac screw fixation can effectively treat Tile C pelvic fracture, and has advantages, including minimal invasiveness, simple operation, short operative time, safe and reliable features, fewer complications, short hospital stay and a good curative effect.

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

OBJECTIVES

To assess the efficiency, safety, and accuracy of S₂ (IS) screw fixation using a robot-assisted method compared with a freehand method.

METHODS

This 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.

RESULTS

A 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.

CONCLUSION

The 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.

Comparison of the feasibility of 3D printing technology in the treatment of pelvic fractures: a systematic review and meta-analysis of randomized controlled trials and prospective comparative studies

PURPOSE

The objective of this meta-analysis was to assess the influence of 3D printing technology on the open reduction and internal fixation (ORIF) of pelvic fractures from current randomized controlled trials and prospective comparative studies.

METHODS

In this meta-analysis, we conducted electronic searches of Pubmed, Embase, Cochrane library, Web of Science and CNKI up to February 2020. We collected clinical controlled trials using 3D printing-assisted surgery and traditional techniques to assist in pelvic fractures, evaluating the quality of the included studies and extracting data. The data of operation time, blood loss, follow-up function (Majeed function score), quality of fracture reduction (Matta score) and complications (infection, screw loosening, pelvic instability, venous thromboembolism, sacral nerve injury) were extracted. Stata 12.0 software was used for our meta-analysis.

RESULTS

Five RCTs and 2 prospective comparative studies met our inclusion criteria with 174 patients in the 3D printing group and 174 patients in the conventional group. There were significant differences in operation time [SMD = - 2.03], intraoperative blood loss [SMD = - 1.66] and postoperative complications [RR = 0.17] between the 3D group and conventional group. And the excellent and good rate of pelvic fracture reduction in the 3D group [RR = 1.32], the excellent and good rate of pelvic function [RR = 1.29] was superior to the conventional group.

CONCLUSIONS

The 3D group showed shorter operation time, less intraoperative blood loss, less complications, better quality of fracture reduction and fast function recovery. Therefore, compared with conventional ORIF, ORIF assisted by 3D printing technology should be a more appropriate treatment of pelvic fractures.

Comparison of lumbopelvic fixation and iliosacral screw fixation for the treatment of bilateral sacral fractures

Background

Bilateral sacral fractures result in traumatic disruption of the posterior pelvic ring. Treatment for unstable posterior pelvic ring fractures should aim for fracture reduction and rigid fixation to facilitate early mobilization. Iliosacral screw fixation (ISF) and lumbopelvic fixation (LPF) were recommended for the treatment of these injuries. No algorithm or gold standard exists for surgery of these fractures.

Purpose

The purpose of this study was to evaluate the differences between ISF and LPF in bilateral sacral fractures regarding intraoperative procedures, complications and postoperative mobilization. The secondary aim was to determine whether demographics influence surgical treatment.

Methods

Over a 4-year period (2016–2019), 188 consecutive patients with pelvic ring injuries were treated at one academic level 1 trauma center and retrospectively identified. Fractures were classified according to the AO/OTA classification system. Seventy-seven patients were treated with LPF or ISF in combination with internal fixation of pubic rami fractures and could be included in this study. Comparisons were made between demographic and perioperative data. Infection, hematoma and hardware malpositioning were used as complication variables. Mobilization with unrestricted weight bearing was used as outcome variable. Follow-up was at least 6 months postoperatively.

Results

Operative stabilization of bilateral posterior pelvic ring injuries was performed in 77 patients. Therefore, 29 patients (females 59%) underwent LPF whereas 48 patients (females 83%) had bilateral ISF. The ISF group was older (76 yrs.) compared to the LPF group (62 yrs.) (p = 0.001), but no differences regarding BMI or comorbidities were detected. Time for surgery was reduced for patients who were treated with ISF compared to lumbopelvic fixation (73 min vs. 165 min; respectively, p < 0.001). But this did not result in reduced fluoroscopic time or radiation exposure. Overall complication rate was not different between the groups. Patients with LPF had a greater length of stay (p = 0.008) but were all weight bearing as tolerated when discharged (p < 0.001).

Conclusion

Bilateral posterior pelvic ring injuries of the sacrum can be sufficiently treated by LPF or ISF. LPF allows immediate weight bearing which may benefit younger patients and patients with an elevated risk for pneumonia or other pulmonary complications. Treatment with ISF reduces operative time, length of stay and postoperative wound infection. Elderly patients may be better suited for treatment with ISF if there is concern that the patient may not tolerate the increased operative time.

Spinopelvic fixation with retention of external fixation in a lateral position for unstable pelvic fracture

Anterior external fixation (EF), as the primary treatment for unstable pelvic fractures, is performed with patients in the supine position. In most cases, however, definitive surgery for posterior fixation is performed first in the prone position without EF. We report the case of a patient with unilateral and vertically unstable pelvic fracture whom we had treated with minimally invasive spinopelvic fixation, with retention of the anterior EF in a lateral position. Reduction of the residual displacement was performed with percutaneous spinal instrumentation, and acceptable reduction was achieved. At the 13-month follow-up, the functional outcome, calculated using the Majeed Score, was 87 points. The plain radiograph showed good bone union, except for the right superior pubic ramus. The radiological outcome, measured using the Matta rating, was excellent. Thus, retaining the EF facilitates safe and accurate reduction without major surgical complications and may offer surgeons an additional management option for such fractures.

Failure of internal fixation of the anterior ring for unstable pelvic fractures, the experience of a single institute

Background

This study aimed to share our experience of anterior ring fixation failure for unstable pelvic fractures and propose corresponding treatment strategies.

Materials

From January 2009 to December 2018, 93 charts of patients with pelvic fractures were retrospectively reviewed. Patients with failure of the anterior ring internal fixation within 3 months after initial surgery were analyzed. Quality of reduction was evaluated using the Majeed scoring system. Patients aging ≥ 18 years, with unstable pelvic fractures, Tile classification type B and type C pelvic fractures, combined injury of other organs that did not affect the operation and without important neurovascular damage were included. The exclusion criteria included: (1) pathological fracture, or combined with pelvic bone tumor or severe osteoporosis; (2) femoral fracture and thoracolumbar fracture; (3) open pelvic fracture; (4) Morel-Lavallée injury; (5) complicated acetabular fracture. The quality of the reduction of the anterior pelvic ring injury was evaluated on the x-ray film using the Majeed scoring system.

Results

According to the Tile classification of fracture, there were 23 cases of type B1, 17 cases of type B2, 11 cases of type B3, 28 cases of type C1, 6 cases of type C2, and 8 cases of type C3. The duration from injury to pelvic internal fixation ranged from 5 to 28 days. Seven out of 93 patients experienced failure of internal fixation of the anterior pelvic ring within 3 months, including 2 patients fixed with an external fixator and 5 patients fixed with a plate. Five patients undergoing revision surgery were followed up for 6–36 months with an average of 18 months. According to Majeed’s score at the last follow-up in the 5 patients undergoing revision surgery, there were 2 cases of excellent, 2 cases of good, 1 case of fair. The excellent and good rate reached 80%.

Conclusion

The treatment of complicated unstable pelvic fractures requires performing internal fixation surgery within 2 weeks. It is necessary to make a preoperative plan and stabilize the posterior ring first, avoiding a single steel plate crossing the pubic symphysis.

Safety and efficacy of surgical hip dislocation in managing femoral head fractures: A systematic review and meta-analysis

BACKGROUND

Femoral head fractures (FHFs) are considered relatively uncommon injuries; however, open reduction and internal fixation is preferred for most displaced fractures. Several surgical approaches had been utilized with controversial results; surgical hip dislocation (SHD) is among these approaches, with the reputation of being demanding and leading to higher complication rates.

AIM

To determine the efficacy and safety of SHD in managing FHFs by reviewing the results reported in the literature.

METHODS

Major databases including PubMed, Embase, Web of Science, and Cochrane Central Register of Controlled Trials were searched to identify studies reporting on outcomes of SHD utilized as an approach in treating FHFs. We extracted basic studies data, surgery-related data, functional outcomes, radiological outcomes, and postoperative complications. We calculated the mean differences for continuous data with 95% confidence intervals for each outcome and the odds ratio with 95% confidence intervals for binary outcomes. P < 0.05 was considered significant.

RESULTS

Our search retrieved nine studies meeting our inclusion criteria, with a total of 129 FHFs. The results of our analysis revealed that the average operation time was 123.74 min, while the average blood loss was 491.89 mL. After an average follow-up of 38.4 mo, a satisfactory clinical outcome was achieved in 85% of patients, with 74% obtained anatomical fracture reduction. Overall complication rate ranged from 30% to 86%, with avascular necrosis, heterotopic ossification, and osteoarthritis being the most common complications occurring at an incidence of 12%, 25%, and 16%, respectively. Trochanteric flip osteotomy nonunion and trochanteric bursitis as a unique complication of SHD occurred at an incidence of 3.4% and 3.8%, respectively.

CONCLUSION

The integration of SHD approach for dealing with FHFs offered acceptable functional and radiological outcomes with a wide range of safety in regards to the hip joint vascularity and the development of avascular necrosis, the formation of heterotopic ossification, and the development of posttraumatic osteoarthritis; however, it still carries its unique risk of trochanteric flip osteotomy nonunion and persistent lateral thigh pain.

Validation of Relative Motion Measurement Method of Lateral Compression Pelvic Fractures During Examination Under Anesthesia

OBJECTIVES

To determine if the relative distance between the acetabular teardrops on unstressed and lateral compressive stress examination under anesthesia (EUA) pelvic fluoroscopic images is reproducible between independent reviewers.

DESIGN

Retrospective database review.

SETTING

Level 1 trauma center.

PATIENTS/INTERVENTION

Fifty-eight patients with a lateral compression type 1 pelvic ring injury who underwent EUA.

MAIN OUTCOME MEASURE

Validation of EUA objective measurements between blinded, independent reviewers using interclass and intraclass correlation coefficients.

RESULTS

There was excellent interobserver and intraobserver reliability between all reviewers. Values for each intraclass correlation coefficients (including 95% confidence intervals) were between 0.96 (0.95-0.098) and 0.99 (0.99-0.99) for all measurements. P values were <0.0001 for all measured parameters.

CONCLUSIONS

The relative change in distance between the acetabular tear drops during lateral compressive EUA of lateral compression type 1 pelvic injuries is reliable between independent reviewers. This allows for accurate, objective measurement of pelvic motion independent of patient size or body habitus.

LEVEL OF EVIDENCE

Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Unilateral lumbopelvic fixation for AO/OTA Type C1 and C2 pelvic fractures: Clinical efficacy and preliminary experiences in 23 patients

PURPOSE

To report the clinical outcomes and preliminary experiences of unilateral lumbopelvic fixation for patients with AO/OTA Type C1 and C2 pelvic fractures.

MATERIALS AND METHODS

Between May 2014 and Dec 2017, 23 consecutive patients with AO/OTA Type C1 and C2 pelvic factures were treated by unilateral lumbopelvic fixation. Estimated blood loss, operation duration, reduction quality, functional outcomes using Majeed scores and complications were evaluated. Subgroup analysis was used to assess the influence of unilateral lumbopelvic fixation on different type of pelvic fractures.

RESULTS

Fifteen patients with Type C1 pelvic fractures and eight patients with Type C2 fractures underwent unilateral lumbopelvic fixation respectively. The mean follow-up time till May 2019 was 34.3 ± 9.9 months (range 17-60 months). Mean estimated blood loss was 473 ml and mean operation duration was 156 min during unilateral lumbopelvic fixation. The mean vertical displacement of pelvis decreased from 10.1 ± 4.9 mm to 3.1 ± 1.9 mm after unilateral lumbopelvic fixation. Majeed score assessments were available for 22 patients. Of these, 13 patients were graded as excellent, 8 were good and one was fair. The results of subgroup analysis showed that there was no difference of estimated blood loss, operation duration, postoperative displacements of pelvis and Majeed scores between the patients with Type C1 and C2 fractures.

CONCLUSION

Unilateral lumbopelvic fixation could provide a well reduction quality and was an effective treatment for AO/OTA Type C1 and C2 pelvic fractures.

STUDY DESIGN

Retrospective evaluation of 23 consecutive patients with AO/OTA Type C1 and C2 pelvic fractures treated by unilateral lumbopelvic fixation.

A systematic review of the transiliac internal fixator (TIFI) for posterior pelvic injuries

OBJECTIVE

To summarize the literature on transiliac internal fixator (TIFI) indications and outcomes for treating posterior pelvic ring injuries.

METHODS

We searched databases for original publications in journals. Biomechanical and clinical studies using a TIFI for posterior pelvic ring injuries were considered for inclusion. The dates of publications that were included ranged from January 2000 until December 2020.

RESULTS

A total of 13 articles were reviewed, including eight clinical studies and five biomechanical tests. We found only case series and no multicenter or randomized study. The clinical studies contained data for a total of 186 cases, including indications, treatments, complications, and outcomes, with a minimum follow-up time of 12 months. All studies reported superior results according to operation time, blood loss, complication, dislocation, and union. One biomechanical test evaluated inferior results.

CONCLUSIONS

The TIFI is a user-friendly and safe device to treat posterior pelvic injuries. It can also be used for acute, high-impact injuries, and fragility fractures. Nevertheless, there is no evidence concerning which types of pelvic fractures are most beneficial. Therefore, further biomechanical and clinical studies are necessary to resolve this question.

Matta's criteria may be useful for evaluating and predicting the reduction quality of simultaneous acetabular and ipsilateral pelvic ring fractures

BACKGROUND

Although the incidence, types, and radiological outcomes of simultaneous ipsilateral pelvic ring and acetabular fractures have been reported, there have been no reports on factors that may affect the quality of acetabular fracture reduction. Here, we evaluate the radiological outcomes of patients treated for simultaneous ipsilateral pelvic and acetabular fractures and analyze the factors that affect the quality of acetabular fracture reduction.

METHODS

We conducted a retrospective review of patients treated for simultaneous ipsilateral pelvic ring and acetabular fractures between 2016 and 2020. Factors that may predict inadequate reduction of the acetabular fracture were analyzed.

RESULTS

Data from 27 hips of 26 patients were collected. AO B2.2 and anterior columnar fractures were the most common types of pelvic ring and acetabular fractures, respectively. Univariate analysis revealed that Matta's criteria for pelvic ring fracture may be useful for predicting fair to poor quality of acetabular fracture reduction on X-rays. Furthermore, associated fractures identified by Letournel's classification system on computed tomography may be predictive of greater step-offs.

CONCLUSIONS

Associated fractures identified via Letournel's classification may contribute to inadequate reduction of acetabular fractures. Matta's criteria for pelvic ring fractures may also be useful for predicting the risk of inadequate reduction of the acetabulum on X-ray scans. These findings may be assessed intraoperatively by fluoroscopy before beginning osteosynthesis for acetabular fractures.

Minimally invasive internal fixation for unstable pelvic ring fractures: a retrospective study of 27 cases

Background

This study aimed to evaluate the radiographic and clinical outcomes of anterior subcutaneous internal fixation (INFIX) with or without posterior fixation for the treatment of unstable pelvic fractures.

Methods

Intraoperative blood loss, operation time, and duration of hospital stay were recorded, and fracture union and postoperative complications were evaluated. The fracture reduction quality was evaluated using the Matta score, pelvic deformity index (PDI), and pubic symphyseal width (PSW). In addition, the functional recovery and general quality of life were evaluated using the Majeed score and the 12-Item Short-Form Survey (SF-12), respectively. Furthermore, sacral nerve injury was evaluated using the Gibbons classification.

Results

Twenty-seven patients (14 males and 13 females) with an average age of 37.4 years were followed up for a mean of 22 months. The average operation time, median intraoperative blood loss, and average duration of hospital stay were 129 ± 47 min, 100 mL, and 22 ± 13 days, respectively. All patients achieved bony union with an average union time of 13.3 weeks. Furthermore, the average PDI and PSW were 0.07 ± 0.04 vs. 0.04 ± 0.03 (P = 0.009) and 1.15 ± 1.36 vs. 0.54 ± 0.17 (P = 0.048) before and after the operation, respectively. In 78% of the patients, the Matta or Majeed scores were excellent or good. The SF-12 physical and mental health scores were 45.1 ± 10.2 and 53.2 ± 6.3, respectively. Furthermore, one superficial surgical site infection, one loosening of INFIX, one lateral femoral cutaneous nerve irritation, one femoral nerve injury, and two implant discomforts due to the bar were noted. Among five patients with sacral nerve injuries, four were asymptomatic, and one just had paresthesia at the last follow-up.

Conclusion

INFIX with or without sacroiliac screws can achieve satisfactory radiographic and functional outcomes in the treatment of unstable pelvic ring fractures.

Trial registration

ChiCTR2000038812. Registered 04 October 2020. Retrospectively registered.

Does transarterial pelvic embolization have a negative effect on perioperative outcomes in pelvic ring injury and acetabular fracture?

OBJECTIVE

The purpose of this study was to determine whether TAE negatively impacted perioperative outcomes in patients who underwent open surgery for pelvic trauma.

METHODS

We retrospectively reviewed the medical records and radiographs of patients who had open surgery for an acute pelvic trauma between February 2014 and May 2017. The patients were classified into two groups: those who underwent TAE and those who did not. We evaluated preoperative demographics and perioperative outcomes between the two groups. Injury type-specific comparisons were also performed.

RESULTS

A total of 136 patients (50 TAE and 86 non-TAE) were included in this study. There were significant differences in preoperative demographics including the type of injury, injury severity score, revised trauma score, surgical approach, initial blood pressure, and the amount of transfusion within 24 h between the two groups. However, no differences in perioperative outcomes were identified except for the amount of total transfusion. There were significant differences between the two groups in the injury type-specific comparisons, specifically in the amount of transfusion within 24 h in patients with pelvic ring injury and in the injury severity score in patients with acetabular fracture. However, there was no difference in perioperative outcomes between the groups for either injury type.

CONCLUSION

In the present study, we were unable to identify negative effects of TAE on perioperative outcomes. Therefore, when considering open surgery subsequent to TAE, there is no evidence of increased risk for negative perioperative outcomes, especially with respect to bone healing and deep infection.

Clinical Results of Acetabular Fracture via the Pararectus versus Ilioinguinal Approach

Objective

To compare the clinical efficacy of pararectus and ilioinguinal approach in the treatment of acetabular fractures.

Methods

A retrospective analysis of the clinical data of 60 patients with acetabular fractures treated by the pararectus approach or the ilioinguinal approach from January 2016 to January 2019 was performed to record all data by comparing the length of the surgical incision, the time to expose the fracture and the amount of blood loss during the operation. Patients were routinely followed up at 1, 6 and 12 months postoperatively. The function of the hip joint after the operation (Improved Merle d' Aubigne and Postel scores) and the complications postoperation were recorded.

Results

There was a significant difference (mean ± SD) in the length of surgical incision [(11.2 ± 1.5) cm vs.(23.8 ± 2.1) cm], and in surgical exposure time [(10.8 ± 1.7) min vs.(19.9 ± 1.9) min] (P < 0.05) between the two approaches; there was no significant difference (mean ± SD) in intraoperative blood loss [(591.8 ± 131.4) mL vs. (614.6 ± 132.7) mL] or in hip function scores at the last follow‐up between the two groups (P > 0.05). In the pararectus approach group, there was one patient (3.3%) with postoperative wound fat liquefaction, and the wound completely improved by secretion culture, enhanced dressing and effective antibiotics, one patient (3.3%) developed lateral femoral cutaneous nerve injury; One case (3.3%) of postoperative myositis ossificans occurred in the ilioinguinal approach group, and there were no obvious symptoms.

Conclusions

These data suggest that for patients with acetabular fractures, both the pararectus approach and the ilioinguinal approach can achieve satisfactory surgical results, but the former has relatively simple operation and small incision length, which is in line with the modern concept of the minimally invasive pelvis.

Achieve Closed Reduction of Irreducible, Unilateral Vertically Displaced Pelvic Ring Disruption with an Unlocking Closed Reduction Technique

OBJECTIVE

To be able to treat irreducible unilateral vertically displaced pelvic ring disruption (UVDPRD) using closed reduction, we introduced a technique named Unlocking Closed Reduction Technique (UCRT) and evaluated its effectiveness with improved pelvic closed reduction system (PCRS).

METHODS

A retrospective study was performed in our department. Between January 2014 and December 2017, 43 patients whose UVDPRD were not successfully reduced using transcondylar traction. Subsequently, they were treated with UCRT using improved PCRS. The study included 19 male and 24 female patients, with a mean age at the time of the operation of 46.2 years. During surgery, operation time and blood loss were recorded. Post-surgical reduction quality was evaluated using Matta scoring criteria and patient lower-extremity functional outcome was evaluated using Majeed functional scoring criteria.

RESULTS

When used with improved PCRS, UCRT achieved pelvic reduction in all 43 cases of irreducible UVDPRD with postoperative pelvic reduction quality rated excellent and good for 42/43 (97.6%) patients according to the Matta scoring criteria (Matta Score < 10 mm). While no post-surgical complications emerged as the direct result of UCRT in this cohort of patients, 8/37 patients who were treated with subcutaneous supra-acetabular pedicle screw internal fixation (INFIX) for anterior ring fixation developed lateral femoral cutaneous nerve injury but recovered 6 months postoperatively. No revision surgery was performed on any of the recruited patients. All patients' lower-extremity functionality was rated excellent with an average Majeed function score of 94.3 during the last follow-up at an average of 41.6 months postoperatively.

CONCLUSION

With excellent surgical and functional outcomes in patients with irreducible UVDPRD, improved PCRS-assisted UCRT proved to be a safe and effective method for the treatment of irreducible UVDPRD.

Iliac Bone Corridors to Host the Transiliac Internal Fixator-An Experimental CT Based Analysis

Background: The transiliac internal fixator (TIFI) is a novel minimally invasive surgical procedure to stabilize posterior pelvic ring fractures. Two bone corridors with different lengths, widths, and angulations are suitable to host screws in the posterior iliac wing. While the length and the width have been described previously, the angulation has not been determined yet. Methods: We created a computer tomography-based 3D-model of 40 patients (20 women, 20 men). The possible bone corridors to host the ilium screws for the TIFIcc (cranio-caudal) and the TIFIdv (dorso-ventral) procedure were identified. After reaching the optimal position, the angles in relation to the sagittal and axial plane were measured. The anterior pelvic plane was chosen as the reference plane. Results: The mean angle of the TIFIcc screws related to the axial plane was 63.4° (±1.8°) and to the sagittal plane was 12.3° (±1.5°). The mean angle of the TIFIdv screws related to the axial plane was 16.1° (±1.2°) and to the sagittal plane was 20.1° (±2.0°). In each group, a high constancy was apparent irrespective of the age or physical dimension of the patient, although a significant gender-dependent difference was observed”. Conclusions: Due to a high inter-individual constancy in length, width, and angulation, bone corridors in the posterior iliac wing are reliable to host screws for posterior pelvic ring fixation irrespective of each individual patient’s anatomy.

Factors Associated With Failure of Superior Pubic Ramus Screws

OBJECTIVE

Examine factors associated with fixation failure in patients treated with superior intramedullary ramus screws.

DESIGN

Retrospective.

SETTING

Single, Level 1 trauma center.

PATIENTS

Unstable pelvic ring fractures amenable fixation that included superior intramedullary ramus screws.

INTERVENTION

Percutaneously inserted intramedullary superior ramus screw fixation of superior pubic ramus (SPR) fractures.

MAIN OUTCOME MEASUREMENTS

Loss of reduction (LOR) of the SPR fracture defined as >2 mm displacement on pelvic radiographs at any time point in follow-up.

RESULTS

Two hundred eighty-five fractures in 211 patients (age 44, 95% confidence interval 40.8%-46.4%, 59.3% women, 55.1% retrograde screws) were included in the analysis. 14 (4.9%) of fractures had LOR. Patients were significantly more likely to have LOR as age increased (P = 0.01), body mass index (BMI) increased (P = 0.01), and if they were women (P < 0.01). There was a significantly decreased LOR (P < 0.01) as fractures moved further from the pubis symphysis. Retrograde screws were significantly (P < 0.01) more likely to have LOR. In SPR fractures treated with retrograde screws, failure was significantly associated with increasing BMI (P = 0.02), the presence of an inferior ramus fracture (P = 0.02), and trended toward significance with increasing age (P = 0.06), and decreased distance from the symphysis (P = 0.07).

CONCLUSIONS

Superior ramus screws are associated with a low failure rate (4.9%), which is lower than previously reported. Retrograde screw insertion, distance from the symphysis, increasing age, increasing BMI, decreased distance from the symphysis, and ipsilateral inferior ramus fractures were predictors of failure. In these patients, alternative modalities should be considered, although low rates of failure can still be expected.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Epidemiological and Therapeutic Developments in Pelvic Ring Fractures Type C from 2004 to 2014 - a Retrospective Data Analysis of 2,042 Patients in the German Pelvic Register (DGU)

BACKGROUND

Pelvic ring fractures type C present a special challenge due to their high instability, the possible accompanying injuries and the high mortality rate of up to 18.9%. The aim of this retrospective analysis was to use the data from the DGU pelvic register to identify changes in the epidemiology and therapy for type C pelvic ring fractures between 2004 and 2014.

MATERIALS AND METHODS

2,042 patients with type C pelvic ring injury were retrospectively included. Three time periods with roughly equal patient groups were specified and differences in epidemiology and the type of therapy were evaluated. For the surgical cases, the time of the operation, the duration of the operation, blood loss, the location of the fracture and the type of osteosynthesis were evaluated and the reduction result was recorded.

RESULTS

For the period under review, there is an age shift in the incidence of a type C pelvic ring fracture towards older age. The isolated pelvic injury has increased, while the proportion of pelvic injuries in the context of polytrauma has steadily decreased. Complications and mortality decreased as a percentage. The tendency towards minimally invasive procedures could be shown in the surgical care. Navigated procedures in the area of the pelvic ring have so far not proven successful.

CONCLUSIONS

We were able to show that the majority of the patients are increasingly old, that there is no relevant trauma in the history and that there is an increase in the isolated pelvic fracture type C and a decrease in the number of polytraumatised or multiply injured patients. In conjunction with mortality from pelvic ring injuries, the successes of standardised, pelvic-specific emergency management, an adapted time of operation outside the vulnerable phase and stable osteosynthesis care, which enable early functional follow-up treatment, are also evident.

Comparison of percutaneous cross screw fixation versus open reduction and internal fixation for pelvic Day type II crescent fracture-dislocation: case-control study

Objective

To investigate the clinical outcomes of percutaneous cross screws internal fixation for pelvic Day type II crescent fracture-dislocation.

Methods

We reviewed 66 consecutive patients undergoing surgical treatment for Day type II crescent fracture-dislocation from June 2005 to December 2017. Percutaneous cross screws internal fixation was performed in 40 patients, and open reduction and internal fixation was performed in 26 patients. The patient characteristics, surgical complications, radiographic and clinical outcomes and were compared.

Results

There was no statistically difference on the mean time from injury to surgery between the two groups. The time of operation, the amount of blood loss, the length of incision, and the hospital stay were significantly shorter in the percutaneous cross screws internal fixation group. No significant difference on Matta scores and Majeed scores between the two groups. The open reduction and internal fixation group resulted in a higher rate of intraoperative hemorrhage, nerve injury, discomfort, and pain.

Conclusion

Percutaneous cross screws internal fixation for Day II type pelvic crescent fracture-dislocation was safe and effective. Minimally invasive fixation had the advantages of short operation and hospitalization time, less intraoperative bleeding, and surgical trauma.

Two-Dimensional Visualization of the Three-Dimensional Planned Sacroiliac Screw Corridor with the Slice Fusion Method

Insertion of sacro-iliac (SI) screws for stabilization of the posterior pelvic ring without intraoperative navigation or three-dimensional imaging can be challenging. The aim of this study was to develop a simple method to visualize the ideal SI screw corridor, on lateral two-dimensional images, corresponding to the lateral fluoroscopic view, used intraoperatively while screw insertion, to prevent neurovascular injury. We used multiplanar reconstructions of pre- and postoperative computed tomography scans (CT) to determine the position of the SI corridor. Then, we processed the dataset into a lateral two-dimensional slice fusion image (SFI) matching head and tip of the screw. Comparison of the preoperative SFI planning and the screw position in the postoperative SFI showed reproducible results. In conclusion, the slice fusion method is a simple technique for translation of three-dimensional planned SI screw positioning into a two-dimensional strict lateral fluoroscopic-like view.

Do Fully Threaded Transiliac-Transsacral Screws Improve Mechanical Stability of Vertically Unstable Pelvic Fractures? A Cadaveric Biomechanical Analysis

OBJECTIVE

To determine whether fully threaded transiliac-transsacral (TI-TS) fixation is biomechanically superior to partially threaded TI-TS fixation of vertically unstable transforaminal sacral fractures.

METHODS

Vertically unstable zone 2 sacral fractures were created in 20 human cadaveric pelves with a unilateral osteotomy and resection of 1 cm of bone through the foramen of the sacrum to represent comminution. Ten specimens received either 2 7.3-mm fully threaded or 2 7.3-mm partially threaded TI-TS screw fixation at the S1 and S2 body, and every specimen received standard 3.5-mm 8-hole parasymphyseal plating anteriorly. Each pelvis was loaded to 250 N at 3 Hz for 100,000 cycles and then loaded to failure. The primary outcome was fracture displacement at the S1 foramen, which was measured at 25,000, 50,000, 75,000, and 100,000 cycles. Secondary outcomes were simulated clinical failure of ≥1 cm displacement at the S1 foramen to determine occurrence probability of failure, and load at failure was defined as 2.5 cm of the linear loading system displacement. Specimens in the fully threaded and partially threaded cohorts were otherwise respectively comparable in regards to age, gender, and bone density.

RESULTS

Five of the 10 TI-TS partially threaded specimens experienced simulated clinical failure with >1 cm displacement at the S1 foramen compared with 0 of the 10 TI-TS fully threaded cohort (50% vs. 0%, P = 0.03). The mean maximal displacement at the S1 foramen was greater in the partially threaded cohort (9.3 mm) compared with the fully threaded cohort (3.6 mm; P = 0.004). Fully threaded specimens also demonstrated greater mean force to failure than the partially threaded specimens (461 N vs. 288 N; P = 0.0001).

CONCLUSIONS

Fully threaded TI-TS screw fixation seems to be mechanically superior to partially threaded fixation in a cadaveric vertically unstable transforaminal sacral fracture model with significantly less displacement of the posterior pelvic ring and greater load to failure.

Traumatic spinopelvic dissociation managed with bilateral triangular osteosynthesis: Functional and radiological outcomes, health related quality of life and complication rates

BACKGROUND

Spinopelvic dissociation (SPD) is difficult to manage and is associated with high mortality and morbidity, including concomitant orthopaedic polytrauma, spine injuries, pelvic ring disruptions, neurological, soft-tissue, and vascular injuries. The purpose of this study is to evaluate the functional and radiological outcomes; health related quality of life and complication rates of patients with traumatic spinopelvic dissociation underwent bilateral triangular osteosynthesis (TOS).

METHODS

The study was approved by the medical school's institutional review board (IRB). Prospective data collection of nineteen consecutive cases of traumatic SPD were included in the study from October 2015 to August 2018. Bilateral TOS was performed to manage all patients with SPD. The clinical outcome for fractures was analyzed with Majeed function assessment. Health Related Quality of Life (HRQoL) was assessed with the EQ-6D questionnaire. The reduction quality was evaluated according to Matta criterion. CT scanning was used to verify the fracture union in patients at 24^th weeks postoperatively.

RESULTS

There were 12 women and 7 men with an average age of 47.2±8.4 years (range, 17-62 years). The average follow-up time was 25.2±3.7 months (average, 22-45 months). The most common mechanism of injury was falling (57%). According to Majeed functional scoring, the results were excellent in 12 cases, good in 5 cases and fair in 2 cases. The median EQVAS score was 78.9±8.4. 15 patients (78.9%) turned back to their original occupation. Pain and mood disorders mainly influenced patients' present general health status. According to Matta criterion for fracture reduction, the results were excellent in 14 cases, good in 4 cases and fair in 1 case. Complications were noted as wound healing problems (26%), implant loosening (5%) and iatrogenic nerve injury (5%).

CONCLUSION

Bilateral TOS demonstrates satisfactory functional and radiological outcomes with low complication rates except infection rate in patients with traumatic spinopelvic dissociation. HRQoL is mainly dominated by pain and mood disorders. 78.9% of the patients turned back to their original occupation. Surgeons should be aware of wound healing problems in case of increased muscle mobilization and degloving injuries.Implant removal is required to improve the lumbopelvic mobility.

Posterior Stabilization of Unstable Sacral Fractures: A Single-Center Experience of Percutaneous Sacroiliac Screw and Lumbopelvic Fixation in 67 Cases

Study Design

This is a retrospective study.

Purpose

Recent advances in intraoperative imaging and closed reduction techniques have led to a shifting trend toward surgical management in every unstable sacral fracture. This study aimed to evaluate the clinicoradiological outcome of the sacroiliac (SI) screw and lumbopelvic fixation (LPF) techniques and thereby delineate the indications for each.

Overview of Literature

Optimal management guidelines for unstable sacral fractures are still lacking probably due to the rarity of these injuries and varying fixation trends.

Methods

Out of the 67 patients, 40 and 27 were in the SI and LPF groups, respectively. The electronic medical record for each patient was reviewed, including patient demographic data, mode of trauma, coexisting injuries, neurological status (Gibbon's four-grade system), Injury Severity Score, time from admission to operative stabilization, type of surgical stabilization, complications, return to the operating room, and treatment outcome measures using Majeed's functional grading system and Matta's radiological criteria. The minimum follow-up period was 2 years.

Results

Noncomminuted longitudinal injuries with normal neurology and acceptable closed reduction have undergone SI screw fixation (n=40). Irreducible, comminuted, or high transverse fractures associated with dysmorphic anatomy or neurodeficit were managed by LPF (n=27). Excellent and good Majeed and Matta scores at 86.57% and 92.54% of the patients, respectively, were postoperatively achieved.

Conclusions

Unstable sacral fractures can be effectively managed with percutaneous SI screw including vertically unstable injuries by paying strict attention to preoperative patient selection whereas LPF can be reserved for comminuted fractures, unacceptable closed reduction, associated neurodeficit, lumbosacral dysmorphism, and high transverse fractures.

[Comparison of effectiveness of anterior subcutaneous internal fixator and plate internal fixation for unstable anterior pelvic ring fractures]

Objective

To compare the effectiveness of anterior subcutaneous pelvic internal fixator (INFIX) and plate internal fixation in treatment of unstable anterior pelvic ring fractures.

Methods

The clinical data of 48 patients with unstable anterior pelvic ring fractures who met the selection criteria between June 2014 and December 2019 were retrospectively analyzed. Among them, 21 cases were treated with INFIX (INFIX group), and 27 cases were treated with plate (plate group). There was no significant difference in gender, age, body mass index, cause of injury, time from injury to operation, Injury Severity Score (ISS), and fracture type between the two groups ( P>0.05). The operation time, intraoperative blood loss, fracture healing time, partial weight-bearing time, and complete weight-bearing time were recorded and compared between the two groups. Matta standard was used to evaluate the quality of fracture reduction, and Majeed score system was used to evaluate the functional recovery of pelvic fracture after operation.

Results

The patients in both groups were followed up for an average of 12.5 months (range, 6-16 months). The operation time and intraoperative blood loss in INFIX group were significantly lower than those in plate group ( t=-11.965, P=0.000; t=-20.105, P=0.000). There was no significant difference in the quality of fracture reduction, fracture healing time, partial weight-bearing time, and complete weight-bearing time between the two groups ( P>0.05). At 14 weeks after operation, there was no significant difference in the scores of pain, working, standing and walking, and total scores between INFIX group and plate group ( P>0.05), but there were significant differences in sitting and sexual intercourse scores ( t=-4.250, P=0.003; t=-6.135, P=0.006). The incidences of lateral femoral cutaneous nerve injury, femoral nerve injury, and heterotopic ossification were significantly higher in INFIX group than in plate group ( P<0.05), while the incidence of incision infection was lower in INFIX group than in plate group ( P<0.05).

Conclusion

Compared with the plate internal fixation, the INFIX internal fixation can obtain the similar effectiveness for the unstable anterior pelvic ring fracture and has the advantages of shorter operation time, less blood loss, and lower risk of infection.

Percutaneous triangular stabilization of type 3 and type 4 fragility fractures of the pelvis usually leads to fracture healing despite high revision rates

This is a monocentric, retrospective study to analyze radiological findings as well as perioperative and postoperative complications in patients who underwent percutaneous triangular stabilization of type 3 and type 4 fragility fractures of the pelvis. From August 2017 to December 2018, 20 patients were treated surgically. Thirteen patients (65%) were followed-up and received a CT scan of the pelvis after an average time of 14.8 months. A total of 5 patients (38%) had to undergo revision surgery, 2 patients (15%) immediately, 3 patients (23%) in the interval. In 84.6% no fracture line was visible in the sacrum. Fracture healing of the anterior pelvic ring was observed in all cases. Our results show that percutaneous triangular stabilization of type 3 and type 4 fragility fractures of the pelvis usually leads to fracture healing. Radiological signs of loosening were observed in 62%, an implant removal due to symptomatic loosening was necessary in 23%.