Posterior Fixation of APC-2 Pelvic Ring Injuries Decreases Rates of Anterior Plate Failure and Malunion

Posterior-only fixation in pelvic fractures: Is it sufficient in lateral compression injuries?

PURPOSE

Lateral compression (LC) injuries account for more than two-thirds of all pelvic fractures. The goal of surgical treatment is to provide adequate stability and early mobilization. The consensus on posterior fixation of such injuries is strong in the literature; however, the necessity of anterior ring fixation is not clear. Therefore, this study was formulated to determine the practicability of posterior-only fixation in LC injuries.

METHODS

Between March 2015 and May 2020, all patients with LC type pelvic ring fractures who were admitted and operated upon in a single level 1 trauma center were included in this cross-sectional observational study. Demographic data, co-morbidities, treatment, types of surgical fixation, concomitant injuries and surgeries, surgical complications, length of hospital stay, injury to weight bearing duration, and follow-up period were documented. Functional outcome and quality of life were assessed using Majeed score and SF-36 questionnaire. Non-normally distributed data were presented as median (Q1, Q3) and normally distributed data were presented as mean ± SD. Spearman's rank correlation coefficient was used for correlation analysis.

RESULTS

A total of 25 patients were included, with a mean age of 29.8 years. All patients were managed operatively with posterior-only fixation. The median Majeed score was 90 (76, 95). The median physical component summary score was 69.37 (38.75, 85.62). The median mental component summary score was 63.95 (39.25, 87.87). There was no significant difference compared to population norms of both physical component summary and mental component summary. Injury to weight bearing time correlated significantly (p = 0.002) with Majeed score as well as SF-36 score (p = 0.044). No other variable had a significant association with outcomes.

CONCLUSION

Posterior-only fixation is sufficient for fixing LC injuries with up to 80% of cases having good to excellent functional outcomes. However, comparative studies with larger sample sizes are needed for further validation.

The clinical relevance of fixation failure after pubic symphysis plating for anterior pelvic ring injuries: an observational cohort study with long-term follow-up

BACKGROUND

Open reduction and plate fixation is a standard procedure for treating traumatic symphyseal disruptions, but has a high incidence of implant failure. Several studies have attempted to identify predictors for implant failure and discussed its impact on functional outcome presenting conflicting results. Therefore, this study aimed to identify predictors of implant failure and to investigate the impact of implant failure on pain and functional outcome.

METHODS

In a single-center, retrospective, observational non-controlled cohort study in a level-1 trauma center from January 1, 2006, to December 31, 2017, 42 patients with a plate fixation of a traumatic symphyseal disruption aged ≥ 18 years with a minimum follow-up of 12 months were included. The following parameters were examined in terms of effect on occurrence of implant failure: age, body mass index (BMI), injury severity score (ISS), polytrauma, time to definitive treatment, postoperative weight-bearing, the occurrence of a surgical site infection, fracture severity, type of posterior injury, anterior and posterior fixation. A total of 25/42 patients consented to attend the follow- up examination, where pain was assessed using the Numerical Rating Scale and functional outcome using the Majeed Pelvic Score.

RESULTS

Sixteen patients had an anterior implant failure (16/42; 37%). None of the parameters studied were predictive for implant failure. The median follow-up time was six years and 8/25 patients had implant failure. There was no difference in the Numerical Rating Scale, but the work-adjusted Majeed Pelvic Score showed a better outcome for patients with implant failure.

CONCLUSION

implant failure after symphyseal disruptions is not predictable, but appears to be clinically irrelevant. Therefore, an additional sacroiliac screw to prevent implant failure should be critically discussed and plate removal should be avoided in asymptomatic patients.

Do we fix front and back of every APC pelvic injury?

HISTORY-A 47-year-old male was on a cliff when he jumped into the water below. He jumped about 50 feet. Upon landing in the water, he felt his legs separate and abduct violently. He was taken to the Emergency unit of the nearest trauma center and was found to have no injuries except to his pelvis. He could not weight bear because of pelvic pain but had normal distal sensory and motor exam and rectal exam. His-pelvis was painful to examination anteriorly with minor left-sided posterior SI pain, and he had no blood at his meatus. X-rays and CT were done, (Figures 1-5).

Fluoroscopic images of the sacroiliac joint alone are unable to identify simulated flexion or extension malreduction of the anterior pelvic ring in AO/OTA 61-B2.3 pelvic injuries

PURPOSE

Reduction of AO/OTA 61-B2.3 (APC2) pelvic fractures is challenging in the setting of anterior ring comminution. The anterior ring is visually much simpler to evaluate for flexion or extension hemipelvis deformity than the posterior ring, except in the setting of comminution, necessitating some other visual reference to judge hemipelvis reduction. We sought to test whether pelvic inlet and outlet fluoroscopy of the contours of the sacroiliac joint could be used in isolation to judge hemipelvis flexion or extension.

METHODS

Symphyseal and anterior SIJ ligaments were cut (6 cadaveric pelvis). The symphysis was held malreduced to produce one centimeter flexion and extension deformity: 1 cm was selected to mimic a maximum clinical scenario. The SIJ was assessed using inlet and outlet fluoroscopy. The scaled width of the SIJ was assessed at the joint apertures and midjoint on both inlet and outlet views. Joint widths in flexion and extension were compared against joint widths measured on the reduced SIJ using paired t-tests.

RESULTS

There was no statistical difference in the superior (p = 0.227, 0.675), middle (p = 0.203, 0.693), and inferior (p = 0.232, 0.961) SIJ widths between hemipelvis flexion or extension models against reduced SIJ on outlet views. There was no statistical difference in the anterior (p = 0.731, 0.662), middle (p = 0.257, 0.655), and posterior (p = 0.657, 0.363) SIJ widths between flexion or extension models against reduced SIJ on inlet views.

CONCLUSION

Inspection of SIJ width on inlet and outlet fluoroscopy cannot detect up to one centimeter of hemipelvis flexion or extension malreduction in the setting of AO/OTA 61-B2.3 (APC2) pelvic fractures with complex anterior injuries.

Identification of subtle residual sacroiliac joint flexion and extension malreductions in AO/OTA 61-C1.2 (APC3) pelvic injuries after provisional anterior ring reduction

PURPOSE

Hemipelvis reduction in the setting of AO/OTA 61-C1.2 (APC3) pelvic injuries can be challenging. A common strategy is to provisionally reduce or fix the anterior ring prior to definitive fixation of the posterior ring. In this scenario, it is difficult to assess whether residual sacroiliac joint (SIJ) widening is due to hemipelvis flexion/extension or lateral displacement. This simulation sought to identify a radiographic marker for posterior ilium flexion or extension malreduction in the setting of a reduced anterior ring.

METHODS

Symphyseal and both anterior and posterior SIJ ligaments were cut in 8 cadaveric pelvis. The symphysis was reduced and wired. One centimeter of posterior flexion or extension at the SIJ was created to mimic the clinical scenario of hemipelvis flexion or extension malreduction, and a lateral compressive force was applied. SIJ widening and the direction of anterior or posterior ileal displacement relative to the contralateral joint were assessed via inlet views. SIJ widening and the direction of cranial or caudal ileal displacement were assessed using outlet views. Comparisons between flexion and extension models used Fisher's exact test.

RESULTS

On outlet views, all flexed hemipelvis demonstrated caudal ileal translation at the superior SIJ, in contrast to all extended hemipelvis demonstrated cranial translation (p < 0.0005); the scenarios were easily distinguishable. Conversely, inlet imaging was unable to identify the direction of malreduction. Flexion/extension scenarios resulted in similar amounts of SIJ widening.

CONCLUSION

Residual flexion and extension hemipelvis malreductions in APC3 injuries after provisional anterior fixation can be differentiated by the direction of ileal displacement at the superior SIJ on the outlet view.

Substitutional semi-rigid osteosynthesis technique for treatment of unstable pubic symphysis injuries: a biomechanical study

BACKGROUND/PURPOSE

The surgical fixation of a symphyseal diastasis in partially or fully unstable pelvic ring injuries is an important element when stabilizing the anterior pelvic ring. Currently, open reduction and internal fixation (ORIF) by means of plating represents the gold standard treatment. Advances in percutaneous fixation techniques have shown improvements in blood loss, surgery time, and scar length. Therefore, this approach should also be adopted for treatment of symphyseal injuries. The technique could be important since failure rates, following ORIF at the symphysis, remain unacceptably high. The aim of this biomechanical study was to assess a semi-rigid fixation technique for treatment of such anterior pelvic ring injuries versus current gold standards of plate osteosynthesis.

METHODS

An anterior pelvic ring injury type III APC according to the Young and Burgess classification was simulated in eighteen composite pelvises, assigned to three groups (n = 6) for fixation with either a single plate, two orthogonally positioned plates, or the semi-rigid technique using an endobutton suture implant. Biomechanical testing was performed in a simulated upright standing position under progressively increasing cyclic loading at 2 Hz until failure or over 150,000 cycles. Relative movements between the bone segments were captured by motion tracking.

RESULTS

Initial quasi-static and dynamic stiffness, as well as dynamic stiffness after 100,000 cycles, was not significantly different among the fixation techniques (p ≥ 0.054).). The outcome measures for total displacement after 20,000, 40,000, 60,000, 80,000, and 100,000 cycles were associated with significantly higher values for the suture technique versus double plating (p = 0.025), without further significant differences among the techniques (p ≥ 0.349). Number of cycles to failure and load at failure were highest for double plating (150,000 ± 0/100.0 ± 0.0 N), followed by single plating (132,282 ± 20,465/91.1 ± 10.2 N), and the suture technique (116,088 ± 12,169/83.0 ± 6.1 N), with significantly lower values in the latter compared to the former (p = 0.002) and no further significant differences among the techniques (p ≥ 0.329).

CONCLUSION

From a biomechanical perspective, the semi-rigid technique for fixation of unstable pubic symphysis injuries demonstrated promising results with moderate to inferior behaviour compared to standard plating techniques regarding stiffness, cycles to failure and load at failure. This knowledge could lay the foundation for realization of further studies with larger sample sizes, focusing on the stabilization of the anterior pelvic ring.

Deciphering data: How should clinical trials change your clinical practice?

INTRODUCTION

The careful consideration of how to apply findings from the scientific literature is important to every physician's clinical practice. This can pose a difficult task, particularly with the increasing speed of technological advances and complexity involved in modern clinical trials. This review introduces a new method, the WHOM criteria (Who, How, Outcomes, Minimizing bias), from which orthopedic surgeons and other physicians can efficiently evaluate novel medical literature for inclusion into their clinical practice.

WHOM CRITERIA

The WHOM framework consists of four steps. The first step, Who, involves confirming whether a sample population studied is similar to one's patient under treatment, in order to ensure the results can be reasonably applied. Second, the How, comprises evaluating the intervention performed and ensuring that it could be reasonably replicated. The third step requires thoroughly evaluating the outcomes used in the study so as to ensure they are clinically meaningful to both the treating physician and the patient. Finally, there must be a careful evaluation of potential sources of bias and the ways in which errors and bias were minimized in all phases of the study.

CONCLUSION

Evidence-based practice should drive clinical decision making whenever the necessary literature is available. This requires the careful evaluation of new literature on a regular basis so that physicians can render safe and effective health care in partnership with their patients. The WHOM criteria are described in order to aid clinicians in navigating published research and change practice when appropriate.

Percutaneous Treatment of Locked Pubic Symphysis with the Anterior Subcutaneous Pelvic Fixator (INFIX): A Case Report

CASE

A 54-year-old woman was involved in a motor vehicle collision and sustained a lateral compression type 1 pelvic ring fracture with pubic symphyseal dislocation or a "locked pubic symphysis." Her injury failed to reduce with closed reduction maneuvers under anesthesia and necessitated a percutaneous reduction using a distraction force applied through supra-acetabular placed pedicle screws. This anterior subcutaneous internal pelvic fixator (INFIX) was also used to stabilize the injury.

CONCLUSION

This is the first reported case where a locked pubic symphysis, which failed standard closed reduction measures, was reduced and stabilized through a percutaneous technique, using the INFIX.

Bony Sacral Volume after Sacro-Iliac Screw Fixation of Pelvic Fractures Is Dependent on Reduction of the Anterior Pelvic Ring

Pelvic ring injuries are uncommon but serious injuries. Percutaneous sacro-iliac screw fixation (SSF) is the standard treatment for posterior stabilization of pelvic fractures. Compression forces of the SSF might cause deformity of the sacrum and the pelvic ring. The aim of this radio-volumetric study is to evaluate the morphometry of the sacrum and pelvic ring in SSF for posterior pelvic fractures. (1) Methods: We conducted a radio-volumetric study measuring the bony sacral volume before and after SSF for a pelvic fracture based on a three-dimensional reconstruction of the pre- and postoperative computed tomography scan of 19 patients with a C-type pelvic fracture. In addition to the bony sacral volume, we assessed the pelvic deformity and the load bearing axis. We compared the results of patients without anterior stabilization (Group A) to patients who had additional ORIF of the anterior pelvic ring. (2) Results: Median age of the patients was 41.2 years (±17.8). All patients received percutaneous SSF with partially threaded 7.3 mm screws. The sacral volume decreased from 202.9 to 194.3 cm³ in group A (non-operative treatment anterior, n = 10) and an increase of sacral volume from 229.8 to 250.4 cm³ in group B (anterior ORIF; n = 9). Evaluation of the pelvic deformity also reflected this trend by a decrease of the ipsilateral load-bearing angle in group A (37.0° to 36.4°) and an increase of this angle in group B (36.3 to 39.9°). (3) Conclusions: Bony sacral volume and pelvic deformity after sacro-iliac screw fixation in pelvic fractures depend on treatment of the anterior pelvic ring. Reduction and fixation of the anterior fracture shows an increase of the bony sacral volume and the load bearing angle leading to a closer to normal reconstruction of the pelvic anatomy.

Surgical stabilisation in equivocal pelvic ring injuries - Into the grey zone

Pelvic ring injuries comprise a spectrum of bony, ligamentous and muscular injuries, described by several common classification systems. However, the majority of injuries lie in areas of intermediate severity, where complexity and variable nature make it extremely hard to define in detail. This fact and associated injuries make it extremely difficult to conduct randomised control trials, with purpose to direct treatment guidelines. Thus, special interest and expertise are required by pelvic trauma surgeons, while surgical indications and fixation methods rely on their experience, at least in part. Namely, a significant grey zone of indication exists. As fixation methods evolve, specifically percutaneous fixation using osseous fixation pathways, some injuries in which morbidity bound with surgical fixation was considered too high relative to its benefits, may be considered eligible for surgical treatment nowadays. Moreover, due to significant progress in the treatment of the acute polytrauma casualties, the survival rate increased over the years, emphasizing the effect of long-term morbidity and functional outcome of pelvic ring injuries. The purpose of this manuscript is to describe the equivocal areas of controversies, hence "the grey zone", and to provide the readership with up-to-date published data. We aimed to collect and detail clinical and radiological clues in the diagnosis of intermediate unstable anterior-posterior compression and lateral compression injuries, and for the selection of treatment methods and sequence. Recent publications have provided some insights into specific injury features that are correlated with increased chance of instability, pain and delay in ambulation. Specific focus is given to the utility of examination under anaesthesia in selected cases. Other publications surveyed the shared experience of pelvic trauma surgeons as for the classification, indication and treatment sequence of pelvic ring injuries. Although the data hasn't matured yet to a comprehensive treatment algorithm, it may serve clinicians well when making treatment decisions in the grey zone of pelvic ring injuries, and serve as a basis for future prospective studies.

Pelvic ring injuries: recent advances in diagnosis and treatment

Pelvic ring injuries typically occur from high-energy trauma and are often associated with multisystem injuries. Prompt diagnosis of pelvic ring injuries is essential, and timely initial management is critical in the early resuscitation of polytraumatized patients. Definitive management of pelvic ring injuries continues to be a topic of much debate in the trauma community. Recent studies continue to inform our understanding of static and dynamic pelvic ring stability. Furthermore, literature investigating radiographic and clinical outcomes after nonoperative and operative management will help guide trauma surgeons select the most appropriate treatment of patients with these injuries.

A biomechanical comparison of superior ramus plating versus intramedullary screw fixation for unstable lateral compression pelvic ring injuries,,

INTRODUCTION

Management of the anterior component of unstable lateral compression (LC) pelvic ring injuries remains controversial. Common internal fixation options include plating and superior pubic ramus screws. These constructs have been evaluated in anterior-posterior compression (APC) fracture patterns, but no study has compared the two for unstable LC patterns, which is the purpose of this study.

METHODS

A rotationally unstable LC pelvic ring injury was modeled in 10 fresh frozen cadaver specimens by creating a complete sacral fracture, disruption of posterior ligaments, and ipsilateral superior and inferior rami osteotomies. All specimens were repaired posteriorly with two fully threaded 7 mm cannulated transiliac-transsacral screws through the S1 and S2 corridors. The superior ramus was repaired with either a 3.5 mm pelvic reconstruction plate (n = 5) or a bicortical 5.5 mm cannulated retrograde superior ramus screw (n = 5). Specimens were loaded axially in single leg support for 1000 cycles at 400 N followed by an additional 3 cycles at 800 N. Displacement and angulation of the superior and inferior rami osteotomies were measured with a three-dimensional (3D) motion tracker. The two fixation methods were then compared with Mann-Whitney U-Tests.

RESULTS

Retrograde superior ramus screw fixation had lower average displacement and angulation than plate fixation in all categories, with the motion at the inferior ramus at 800 N of loading showing a statistically significant difference in angulation.

CONCLUSION

Although management of the anterior ring in unstable LC injuries remains controversial, indications for fixation are becoming more defined over time. In this study, the 5.5 mm cannulated retrograde superior ramus screw significantly outperformed the 3.5 mm reconstruction plate in angulation of the inferior ramus fracture at 800 N. No other significance was found, however the ramus screw demonstrated lower average displacements and angulations in all categories for both the inferior and superior ramus fractures.

Both-Column Acetabular Fractures: Should Pelvic Ring Reduction or Acetabulum be Performed First?

OBJECTIVE

Both-column acetabular fracture is a type that accumulates both the pelvis and acetabulum with complex fracture line alignment and has variant fracture fragments. The selection of different reduction landmarks and sequences produces different qualities of reduction. This study aims to compare the operation-related items, quality of reduction, and hip functional outcome by using different reduction landmarks and sequences for management of both-column acetabular fractures (BCAF).

METHODS

A consecutive cohort of 42 patients from January 2013 to January 2019 with BCAF were treated operatively with different reduction landmarks and sequences: pelvic ring fractures reduction first (PRFRF group) and acetabular fractures reduction first (AFRF group). Preoperative computer visual surgical procedures were applied. There were 22 patients in PRFRF group and 20 patients in AFRF group. The surgical details, complications, radiographic and clinical results were recorded. The quality of reduction was assessed by the Matta scoring system. The functional outcome was evaluated by the modified Merle d'Aubigné and Postel scoring system. The measurement data were analyzed using the t-test of independent samples and rank-sum test of ranked data.

RESULTS

The real reduction sequence in both groups was almost identical to the preoperative surgical procedures. The excellent/good quality of reduction in PRFRF group (21/22) was better than AFRF group (17/20). Operative time (152.3 ± 16.3 mins) and intra-operative blood loss (639.5 ± 109.9ml) were significantly reduced in PRFRF group (p < 0.05). The incidence of deep vein thrombosis in PRFRF group (2/22) was less than AFRF group (4/20), but without statistical signification.

CONCLUSION

Selection of an appropriate reduction landmark and sequence could result in better quality of reduction, operative time, and decreased blood loss during treatment of BCAF.

Biomechanical evaluation of seven fixation methods to treat pubic symphysis diastasis using finite element analysis

Background

Pubic symphysis diastasis (PSD) hinders the connection between bilateral ischia and pubic bones, resulting in instability of the anterior pelvic ring. PSD exceeding 25 mm is considered disruptions of the symphyseal and unilateral/bilateral anterior sacroiliac ligaments and require surgical intervention. The correct choice of fixation devices is of great significance to treat PSD. This study aimed to evaluate the construct stability and implant performance of seven fixation methods to treat PSD using finite element analysis.

Methods

The intact skeleton-ligament pelvic models were set as the control group. PSD models were simulated by removing relevant ligaments. To enhance the stability of the posterior pelvic ring, a cannulated screw was applied in the PSD models. Next, seven anterior fixation devices were installed on the PSD models according to standard surgical procedures, including single plates (single-Plate group), single plates with trans-symphyseal cross-screws (single-crsPlate group), dual plates (dual-Plate group), single cannulated screws, dual crossed cannulated screws (dual-canScrew group), subcutaneous plates (sub-Plate group), and subcutaneous pedicle screw-rod devices (sub-PedRod group). Compression and torsion were applied to all models. The construct stiffness, symphyseal relative micromotions, and von Mises stress performance were recorded and analyzed.

Results

The construct stiffness decreased dramatically under PSD conditions. The dual-canScrew (154.3 ± 9.3 N/mm), sub-Plate (147.1 ± 10.2 N/mm), and sub-PedRod (133.8 ± 8.0 N/mm) groups showed better ability to restore intact stability than the other groups (p < 0.05). Regarding regional stability, only single-plate fixation provided unexpected regional stability with a diastasis of 2.1 ± 0.2 mm (p < 0.001) under a compressive load. Under a rotational load, the single-crsPlate group provided better regional angular stability (0.31° ± 0.03°, p < 0.001). Stress concentrations occurred in the single-Plate, sub-Plate, and sub-PedRod groups. The maximum von Mises stress was observed in the single-plate group (1112.1 ± 112.7 MPa, p < 0.001).

Conclusion

The dual-canScrew fixation device offers ideal outcomes to maintain stability and prevent failure biomechanically. The single-crsPlate and dual-Plate methods effectively improved single-Plate device to enhance regional stability and disperse stresses. The subcutaneous fixation devices provided both anterior pelvic ring stability and pubic symphysis strength.

Percutaneous screw fixation of pubic symphysis disruption: A preliminary report

BACKGROUND

Percutaneous techniques are commonly used to treat pelvic ring disruptions but are not mainstream for fixation of pubic symphysis disruption worldwide. Potential advantages include less blood loss and lower risk of surgical site infection, especially in the morbidly obese or multiply injured patient. This study was performed to describe the clinical and radiographic outcomes of patients after percutaneous reduction and screw fixation of pubic symphysis disruption and to evaluate the preliminary safety and efficacy of this technique and its appropriateness for further study as an alternative method of fixation.

METHODS

A retrospective review was performed to identify all patients who underwent percutaneous fixation of pubic symphysis disruption by two surgeons at an academic Level I trauma center over a 3-year period. Patients underwent percutaneous reduction and fixation of the pubic symphysis using 1 or 2 fully or partially threaded 5.5, 6.5, or 7.3 mm cannulated screws in a transverse or oblique configuration. Associated posterior ring injuries were fixed with trans-sacral and/or iliosacral screws. The primary outcome of interest was loss of reduction, defined as symphysis distance greater than 15 mm measured on final AP pelvis radiograph. Secondary outcomes collected by chart review were operative time, blood loss, vascular or urologic injury, sexual dysfunction, infection, implant loosening or breakage, and revision surgery.

RESULTS

Twelve patients met criteria and primary and secondary outcomes were collected. Mean clinical and radiographic follow-up were 15 months each. One patient lost reduction. Mean operative time and blood loss were 124 min and 29 cc, respectively. No vascular or urologic injuries occurred. Two patients reported sexual dysfunction. No patients became infected or required revision surgery. Four patients underwent implant removal. Seventeen additional patients were excluded due to short follow-up and limited outcomes were collected. Two of these patients lost reduction. Three underwent implant removal.

CONCLUSION

These data support percutaneous reduction and screw fixation of pubic symphysis disruption as a potentially safe and effective method of treatment that warrants further investigation.

A biomechanical in-vitro study on an alternative fixation technique of the pubic symphysis for open book injuries of the pelvis

PURPOSE

Implant failure rates remain high after plate fixation in pelvic ring injuries. The aim of this study was to compare an alternative fixation technique with suture-button devices and anterior plate fixation in partially stable open-book injuries.

MATERIAL AND METHODS

We acquired 16 human fresh frozen anatomic pelvic specimens. The sacrospinous, sacrotuberous, and anterior sacroiliac ligaments were bilaterally released, and the pubic symphysis transected to simulate a partially stable open-book (AO/OTA 61-B3.1) injury. The specimens were randomly assigned to the two fixation groups. In the first group two suture-button devices were placed in a criss-crossed position through the symphysis. In second group a six-hole plate with standard 3.5 unlocked bicortical screws was used for fixation. Biomechanical testing was performed on a servo-hydraulic apparatus simulating bilateral stance, as described by Hearn and Varga. Cyclic compression loading with a progressively increasing peak load (0.5 N/cycle) was applied until failure. The failure mode, the load and the number of cycles at failure and the proximal and distal distance of the symphysis during testing were compared.

RESULTS

There was no implant failure in either of the two groups. Failures occurred in nine pelvises (56.2%) at the fixation between the sacrum and the mounting jig and in seven pelvises (43.8%) in the sacroiliac joint. Neither the ultimate load nor the number of cycles at failure differed between the surgical techniques (p = 0.772; p = 0.788, respectively). In the suture button group the mean ultimate load was 874.5 N and the number of cycles at failure was 1907.9. In the plate group values were 826.1 N and 1805.6 cycles, respectively. No significant differences at proximal and distal diastasis of the symphysis were monitored during the whole loading process.

CONCLUSION

The fixation with suture button implants showed comparable results to anterior plate fixation in open-book injuries of the pelvis.

Danger zone - The spermatic cord during anterior plating of the symphysis pubis

BACKGROUND

Distances between anatomic landmarks and anatomic structures at risk are often underestimated by surgeons.

PURPOSE

The goal of the study was to evaluate the distances between anatomic landmarks and the spermatic cord in case of anterior plating of the symphysis.

METHODS

A total of 25 pelves (50 hemipelves) of male embalmed cadavers were dissected. A 5-hole 3.5mm locking compression plate (Synthes GmbH) was fixed from directly anterior on the symphysis. Measurements were taken 1) distance between the tips of both pubic tubercles, 2) horizontal interval between the lateral border of the plate and the medial margin of the SC (bilateral), 3) distances between the medial border of the SC and the tip of the pubic tubercle (bilateral), 4) distances between the medial border of the SC and the lateral basis of the pubic tubercle (bilateral).

RESULTS

The distance between the pubic tubercles was 60.3mm in average (SD: 5.7). The interval between the lateral border of the plate and the medial margin of the SC was on average 4.5mm (SD: 1.9) on the right and 4.7mm (SD: 2.6) on the left side. The distance between the tip of the pubic tubercle and the medial border of the SC was in average 11.2mm (SD: 2.7) on the right, and 11.0mm (SD: 2.7) on the left side. The average distance between the medial border of the SC and the lateral basis of the pubic tubercle was 8.1mm (SD: 2.4) on the right and 8.2 mm (SD: 2.4) on the left side.

CONCLUSION

The SC is at risk not only during dissection but also during anterior plating of the symphysis, because of its close relation to the SC.

CLINICAL RELEVANCE

Average distances between the palpable pubic tubercle and the SC are below one finger breadth (as reference).

No clinical advantage of locking over nonlocking plate fixation of symphyseal disruptions

PURPOSE

although locking plates have led to important changes in fracture management, becoming important tools in the orthopedic surgeon's arsenal, the benefits of locking plates for traumatic diastasis of the pubic symphysis have not been established. This study was conducted to assess the quality of life in its different domains among patients with traumatic diastasis of the pubic symphysis managed either with locking or nonlocking plate.

METHODS

a prospective cohort study was undertaken at 3 level 1 trauma centres in Brazil. Patients presenting traumatic diastasis of the pubic symphysis treated with plate fixation with a minimum follow-up of 12 months were eligible for inclusion. Through a Pfannenstiel approach, the pubic symphysis was reduced and fixed with a superiorly positioned 4.5mm four to six hole reconstruction locked plate or 3.5mm four to six hole reconstruction nonlocked plate. Posterior injury was managed during the same procedure. Outcome measures were adequate healing of the pelvic injuries, return to pre-injury level on daily activities, and quality of life at the last follow-up visit. Complications and modes of failure were summarized and reviewed. Bivariate linear regression was used to assess individual factors affecting patients' health-related quality of life. A p value of <5% was considered significant.

RESULTS

a total of 31 adult patients (29 males and 2 females) were eligible for the study. Thirteen patients were managed with a reconstruction locked plate and 18 patients with a nonlocked reconstruction plate. Average postoperative follow-up time was 24 months. Adequate healing of the pelvic injuries was achieved in 61.5% of patients treated with locking plates and 94.4% of patients treated with nonlocking plates (p=0.003). Radiographic failure of fixation with minor complications occurred in 46.1% of patients after locked plating versus 11.1% of patients in the nonlocking plate group (p=0.0003). In bivariate analysis, abnormal gait (p=0.007) was associated with a reduced long-term quality of life as measured with the EQ-5D-3L.

CONCLUSION

internal fixation of traumatic diastasis of the pubic symphysis with locking plates has no clinical advantage when compared to nonlocked plating. Mechanical failure and inadequate healing are significantly increased after locked plating of the pubic symphysis. Therefore, we do not recommend routine use of locking plates for managing patients presenting traumatic diastasis of the pubic symphysis.

LEVEL OF EVIDENCE

II (prospective, cohort study).

Fixation failure in patients with traumatic diastasis of pubic symphysis: impact of loss of reduction on early functional outcomes

Background

Failure of fixation (FF) in pubic symphysis diastasis (SD) ranges between 12 and 75%, though whether it influences functional outcomes is still debated. The objective of this study is to evaluate the impact of anterior pelvic plate failure and loss of reduction on Majeed’s functional scores.

Methods

Single center retrospective review of consecutive patients with acute SD treated by means of anterior pubic plating. Thirty-seven patients with a mean age 45.7 ± 14.4 years were included. Demographics, AO classification, pelvic fixation and secondary procedures were recorded. Majeed’s functional scores at minimum 6 months follow-up were compared according to the presence of FF and loss of reduction.

Results

Fifteen patients presented FF. Eight presented an additional loss of symphyseal reduction. Mean Majeed´s score (MMS) in patients with and without FF was 64.4 ± 13.04 and 81.8 ± 15.65, respectively (p = 0.0012). Differences in MMS in patients without FF and those with FF and maintained or loss of anterior reduction were 11.3 [70.5 vs 81.8] (p = 0.092) and 22.7 [59.1 vs 81.8] (p = 0.001), respectively. Significant association of FF with AO classification was noted. (OR 12.6; p = 0.002).

Conclusions

Differences in MMS in the analyzed groups suggest that loss of reduction might be more relevant than failure of the anterior osteosynthesis in functional outcomes.

Can locking plate fixation of symphyseal disruptions allow early weight bearing?

INTRODUCTION

Anterior pubic symphyseal plate fixation is the recommended treatment for disruption of pubic symphysis in an unstable pelvic ring injury. The rigid construct offered by locking symphyseal plate has the theoretical advantage of allowing patients to weight bear early. However, there are concerns of catastrophic failure about the locked plate construct. The purpose of the study was to establish if locking plate fixation for pubic symphysis disruption was effective to allow patients to mobilise weight bearing immediately after surgery.

PATIENT AND METHODS

Retrospective analysis of a prospectively collected database from a single centre was performed. The study period was from 2008 to 2017. Radiographic evidence of fixation failure, revision surgery, removal of metalwork and follow up duration was noted.

RESULTS

We identified 46 patients (F:M 8:38) with a mean age of 46 years (range 14 to 74 years). Based on the mechanism of injury patients were classified into Antero-posterior compression (28), Vertical shear [10], lateral compression [4] and combined mechanism [4]. Either a 4-hole or 6-hole locking plate was used in all patients, depending on fracture extension. Posterior fixation was required in 28 (61%) patients. All patients were allowed to fully or partial weight bear. The mean radiological follow-up period was 31 weeks with 13 (28%) patients having evidence of radiological failure. Revision was performed in 1 (2%) patient, in whom the screws had pulled out of the bone. The most common mode of failure was either the screw backing out from the plate or broken screw. Among the 4 (8%) patients who had their metalwork removed, 1 (2%) had delayed onset of infection, 2 (4%) had symptoms related to backed out screw and 1 (2%) opted electively to have metalwork removed.

CONCLUSIONS

With our series of patients, we have found that using locking plate for pubic symphyseal diastasis is safe and effective in allowing patients to weight bear early. A low complication rate and need for re-operation is demonstrated.

Can preoperative radiographs predict hardware complication or fracture displacement after operative treatment of pelvic ring injuries?

INTRODUCTION

Operative fixation of pelvic ring injuries is associated with a high risk of hardware failure and loss of reduction. The purpose of this study was to determine whether preoperative radiographs can predict failure after operative treatment of pelvic ring injuries and if the method of fixation effects their risk.

PATIENTS AND METHODS

We conducted a retrospective cohort study of 143 patients with pelvic ring injuries treated with operative fixation at a level 1 trauma center. Preoperative radiographs were examined for the presence of the following characteristics: bilateral rami fractures, segmental or comminuted rami fractures, contralateral anterior and posterior injuries, complete sacral fracture, and displaced inferior ramus fractures. The method of fixation was classified based on the presence of anterior, posterior, or combined anterior and posterior fixation as well as whether or not posterior fixation was performed at a single or multiple sacral levels. Post-operative radiographs were examined for hardware failure or loss of reduction.

RESULTS

Twenty-one patients (14.7%) demonstrated either hardware complication or fracture displacement within 6 months of surgery. Male sex was associated with a decreased risk of hardware complication (OR 0.11 [0.014, 0.86]; p=0.03). Posterior pelvic ring fixation at multiple sacral levels was associated with a decreased risk of fracture displacement (OR 0.21 [0.056, 0.83]; p=0.02). We were unable to demonstrate a significant association between preoperative radiographic characteristics and risk of hardware failure or fracture displacement.

CONCLUSION

Our study demonstrates that both gender and the method of posterior fixation are associated with hardware failure or displacement.

Plate fixation of the anterior pelvic ring in patients with fragility fractures of the pelvis

Introduction

In fragility fractures of the pelvis (FFP), fractures of the posterior pelvic ring are nearly always combined with fractures of the anterior pelvic ring. When a surgical stabilization of the posterior pelvis is performed, a stabilization of the anterior pelvis is recommended as well. In this study, we aim at finding out whether conventional plate osteosynthesis is a valid option in patients with osteoporotic bone.

Materials and methods

We retrospectively reviewed medical charts and radiographs of all patients with a FFP, who underwent a plate osteosynthesis of the anterior pelvic ring between 2009 and 2019. Patient demographics, fracture characteristics, properties of the osteosynthesis, complications and revision surgeries were documented. Single plate osteosynthesis (SPO) at the pelvic brim was compared with double plate osteosynthesis (DPO) with one plate at the pelvic brim and one plate anteriorly. We hypothesized that the number and severity of screw loosening (SL) or plate breakage in DPO are lower than in SPO.

Results

48 patients with a mean age of 76.8 years were reviewed. In 37 cases, SPO was performed, in 11 cases DPO. Eight out of 11 DPO were performed in patients with FFP type III or FFP type IV. We performed significantly more DPO when the instability was located at the level of the pubic symphysis (p = 0.025). More patients with a chronic FFP (surgery more than one month after diagnosis) were treated with DPO (p = 0.07). Infra-acetabular screws were more often inserted in DPO (p = 0.056). Screw loosening (SL) was seen in the superior plate in 45% of patients. There was no SL in the anterior plate. There was SL in 19 of 37 patients with SPO and in 3 of 11 patients with DPO (p = 0.16). SL was localized near to the pubic symphysis in 19 of 22 patients after SPO and in all three patients after DPO. There was no SL in DPO within the first month postoperatively. We performed revision osteosynthesis in six patients (6/48), all belonged to the SPO group (6/37). The presence of a bone defect, unilateral or bilateral anterior pelvic ring fracture, post-operative weight-bearing restrictions, osteosynthesis of the posterior pelvic ring, and the presence of infra- or supra-acetabular screws did not significantly influence screw loosening in SPO or DPO.

Conclusion

There is a high rate of SL in plate fixation of the anterior pelvic ring in FFP. In the vast majority, SL is located near to the pubic symphysis. DPO is associated with a lower rate of SL, less severe SL and a later onset of SL. Revision surgery is less likely in DPO. In FFP, we recommend DPO instead of SPO for fixation of fractures of the anterior pelvic ring, which are located in or near to the pubic symphysis.

[Outcome after plate stabilization of symphyseal diastasis]

Hintergrund

Die Symphysensprengung mit entsprechender Diastase kann durch eine Symphysenplatte stabilisiert werden.

Fragestellung

Welche Beckenverletzungen werden mit einer Symphysenplatte stabilisiert und wie ist das Outcome?

Material und Methoden

Retrospektive Auswertung von 64 Patienten über einen Untersuchungszeitraum von 24 Monaten.

Ergebnisse

Es waren 56 Patienten männlich, 8 weiblich und das mittlere Alter betrug 44 Jahre (SD ± 17). Unfälle im Straßenverkehr waren der führende Grund für die Beckenverletzung. Die Verteilung nach AO-Klassifikation zeigte sich wie folgt: 14-mal B1-, 10-mal B2-, 5‑mal B3-, 23-mal C1-, 9‑mal C2- und 3‑mal C3-Verletzungen. Die Verteilung nach Young und Burgess ergab: 9‑mal APC-I-, 18-mal APC-II-, 13-mal APC-III-, 9‑mal LC-I-, 3‑mal LC-II-, 2‑mal LC-III- und 10-mal VS-Verletzungen. Der mittlere Injury Severity Score (ISS) betrug 32 und die mittlere stationäre Verweildauer 29 Tage (pos. Korrelation p ≤ 0,001). Im Verlauf war eine radiologische Implantatlockerung bei 52 Patienten nachweisbar. Therapierelevante Komplikationen gab es in 14 Fällen. Hierbei war das Implantatversagen (n = 8) der Hauptgrund für eine operative Revision.

Diskussion

Obwohl die radiologische Implantatlockerung häufig beobachtet wird, ist sie nur selten Grund für einen Revisionseingriff. Kommt es hingegen zum vollständigen Implantatversagen, tritt dies meist innerhalb der ersten postoperativen Wochen auf und ist revisionsbedürftig. Eine frühzeitige Abklärung durch Röntgenbildgebung sollte bei Verdacht erfolgen.

Cannulated iliac screw fixation combined with reconstruction plate fixation for Day type II crescent pelvic fractures

Objective

Method

Results

Conclusion

Assessment of instability in type B pelvic ring fractures

Pelvic ring fractures have increased in incidence and operative fixation over the past several decades. These are dynamic injuries but decisions on operative management are still often made on the basis of static imaging. Expert opinion varies greatly on which injuries require fixation and how much fixation. Examination under anaesthesia has been shown to guide management of pelvic injuries by more accurately assessing levels of instability.

Posterior tension band plate osteosynthesis for unstable sacral fractures: A preliminary study

INTRODUCTION

Stable reduction and rigid fixation of the sacrum and posterior ring structures are of paramount importance in the management of complex pelvic ring disruptions, Tile B and C. The major concern with the use of conventional methods, like iliosacral screws and iliolumbar fixations is the increased risk for surgical and implant-related morbidity, especially in difficult situations, such as comminuted, bilateral sacral fractures, and fractures in the dysmorphic sacrum. Although various biomechanical studies have reported the posterior trans-iliac plates to provide maximum resistance to distracting forces by the principle of tension band, the literature pertaining to this implication in clinical studies has been limited. The purpose of our study was to assess the efficacy of the trans-iliac plate in the management of unstable sacral fractures and its utility in pelvic disruptions associated with surgical site morbidity.

METHODOLOGY

The patients with unstable pelvic fractures (Tile B and C) between 2013 and 2017 were retrospectively analyzed at a trauma center. First, the anterior ring disruptions were stabilized, and then, the sacral fractures (Denis Zone 1-3) treated by posterior tension band plate osteosynthesis (3.5 mm reconstruction plate) were included. Demographic and perioperative data were assessed. The outcome variables studied were surgical morbidity, pain, loss of reduction, and union and implant-related complications. The outcomes were graded using Lindhal's (radiological) and Majeed (functional assessment) scores.

RESULTS

Thirteen patients (nine male/four female) with a median age of 42 years, had sacral fractures in Denis zones 1/2/3 (four/ten/one, respectively), resulting from Tile pelvic injury B and C were included. The pelvis in five patients was stabilized only with the posterior plate due to the anteriorly-associated surgical site morbidity (Morel-Lavallee lesions and urinary tract injuries). The mean follow-up was 21.5 ± 2.8 months. All fractures had a radiological union by 22 weeks; Lindhal's grade A in ten patients and grade B in three patients. Two out of three patients recovered from preoperative neurological involvement. Two had complained of implant prominence (BMI<19 kg/m²) and there were no implant failures. Four had excellent, six had good, and three had fair or poor functional outcomes.

CONCLUSION

The posterior trans-iliac plate is a minimally invasive and safe procedure that can be used in a wide range of unstable sacral fractures with notably less implant failure rate. The rigid posterior construct restores the principle tension between the iliac blades and minimizes the secondary displacement of the anterior disrupted structures, thereby useful in managing ring disruptions with surgical site morbidity.

Fixation of Anterior Pelvic Ring Injuries

Treatment of anterior pelvic ring injuries involves both acute stabilization during the initial resuscitation and definitive fixation. Definitive management has evolved substantially over the past 40 years with improved patient mobilization and long-term outcomes. Although its use has recently declined, external fixation remains a favorable option in certain situations. Symphyseal plating is the preferred technique for stabilization of symphyseal diastasis because of superior stability and low morbidity. Ramus screws can be effective for simple ramus fractures but require a careful technique because of the proximity of neurovascular structures. The subcutaneous internal fixator provides a good option for obese patients in whom external fixation would be poorly tolerated. Regardless of fixation strategy, posterior ring reduction and stabilization is crucial.

Current Trends in the Surgical Treatment of Open-Book Pelvic Ring Injuries: An International Survey Among Experienced Trauma Surgeons

INTRODUCTION

In the open-book, rotationally unstable (OTA/AO type 61-B1.1) pelvic ring injury, the posterior sacroiliac complex is believed to remain intact. Therefore, anterior ring stabilization alone has been the standard treatment recommendation. However, treatment failures using this method have caused a reconsideration of this management strategy. Anterior plus posterior fixation is the main alternative. In the absence of any specific new guidelines, the choice of treatment currently relies on the preference of the treating surgeon. The objective of this survey was to determine the relative use of anterior plus posterior fixation, as opposed to the standard anterior fixation alone, for the treatment of open-book pelvic ring injuries.

METHODS

An international group of 176 practicing trauma surgeons experienced in pelvic ring fracture fixation participated in an AO Foundation survey asking for their preferred standard surgical fixation (anterior alone or anterior plus posterior combined) for OTA/AO type 61-B1.1 open-book pelvic fractures.

RESULTS

Anterior plate fixation alone (group 1) was preferred by 56% of the survey participants, and combined anterior plus posterior fixation (group 2) was preferred by 44%. Statistical analysis revealed that group 1 participants were significantly older than group 2 participants (P = 0.03) and had more years of surgical experience (P = 0.02).

CONCLUSIONS

Concern regarding the inadequacy of anterior fixation alone has led many surgeons, especially those more recently in practice, to add posterior fixation, despite limited data to determine its indications. No doubt the OTA/AO type B 1.1 pelvic ring disruption actually represents a wide spectrum of injury. Further study is needed to determine the best fixation method.

Unstable Pelvic Ring Injuries: How Soon Can Patients Safely Bear Weight?

OBJECTIVE

To determine if time to weight bearing (WB) is associated with complications in operatively treated pelvic ring injuries.

DESIGN

Retrospective cohort study.

SETTING

Academic Level I trauma hospital.

PATIENTS

Two hundred eighty-six patients with pelvic ring injuries treated operatively over a 10-year period [OTA/AO 61-B1-3, 61-C1-3; Young-Burgess lateral compression (LC) 1-3, anterior-posterior compression (APC) 1-3, and vertical shear] were included.

INTERVENTION

Patients were stratified into early (≤8 weeks) and late (>8 weeks) time to full WB groups.

MAIN OUTCOME MEASURE

Composite outcome of implant failure [broken screw(s)/plate(s), screw(s) loosening], revision surgery, and malunion.

RESULTS

We identified 286 patients with a mean age of 39.9 years (range: 18-81 years) and an average follow-up of 1.2 years (1.0-9 years). There were 132 and 154 patients in the early and late WB groups, respectively. A total of 142 Young-Burgess LC-1, 48 LC-2, 23 LC-3, 10 APC-1, 45 APC-2, 8 APC-3, and 8 vertical shear injuries were noted. Complications were noted in 47 patients (16%). Complications included 18 implant failures, 16 malunions, and 13 patients who required revision operations for loss of reduction. Time to WB was not associated with composite complication rates (P = 0.24). APC-2, LC-3, and injuries with bilateral rami fractures were noted to have a higher complication rates independent of time to WB (P = 0.005, 0.03, and 0.03, respectively).

CONCLUSIONS

No difference in implant failure, malunion, or early loss of reduction between operatively treated pelvic ring injuries allowed to WB as tolerated before 8 weeks compared with those who remained on protected WB protocol for any time greater than 8 weeks was noted. These data may provide information to support early WB protocols.

LEVEL OF EVIDENCE

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

A biomechanical cadaver comparison of suture button fixation to plate fixation for pubic symphysis diastasis

OBJECTIVES

To determine whether suture button fixation of the pubic symphysis is biomechanically similar to plate fixation in the treatment of partially stable pelvic ring injuries.

METHODS

Twelve pelvis specimens were harvested from fresh frozen cadavers. Dual-x-ray-absorptiometry (DXA) scans were obtained for all specimens. The pubic symphysis of each specimen was sectioned to simulate a partially stable pelvic ring injury. Six of the pelvises were instrumented using a 6 hole, 3.5 mm low profile pelvis plate and six of the pelvises were instrumented with two suture button devices. Biomechanical testing was performed on a pneumatic testing apparatus in a manner that simulates vertical stance. Displacement measurements of the superior, middle, and inferior pubic symphysis were obtained prior to loading, after an initial 440 N load, and after 30,000 and 60,000 rounds of cyclic loading. Statistical analysis was performed using Wilcoxon-Mann-Whitney tests, Fisher's exact test, and Cohen's d to calculate effect size. Significance was set at p < 0.05.

RESULTS

There was no difference between groups for DXA T scores (p = 0.749). Between group differences in clinical load to failure (p = 0.65) and ultimate load to failure (p = 0.52) were not statistically significant. For symphysis displacement, the change in fixation strength and displacement with progressive cyclic loading was not significant when comparing fixation types (superior: p = 0.174; middle: p = 0.382; inferior: p = 0.120).

CONCLUSION

Suture button fixation of the pubic symphysis is biomechanically similar to plate fixation in the management of partially stable pelvic ring injuries.

Minimally invasive screw fixation is as stable as anterior plating in acetabular T-Type fractures - a biomechanical study

INTRODUCTION

Operative treatments of T-type acetabular fractures are challenging surgical procedures. Open reduction and internal fixation is the standard method for the operative management of these fractures, however this is associated with high blood loss, long hospital stay and longer rehabilitation. Anterior subcutaneous pelvic fixation (internal fixation=INFIX) and retrograde pubic screw fixation have shown promising results in minimally invasive treatment of pelvic ring fractures. For T-type acetabular fractures, however, minimally invasive treatment concepts are still rare. Therefore we performed a mechanical in vitro study to: - investigate the potential favorability of minimally invasive treatment options over the already established open anterior locking plate osteosynthesis of acetabular T-fractures regarding biomechanical stability and post-surgical stiffness; - explore the biomechanical feasibility of the INFIX; - assess its potential ability to reduce the anterior acetabular column.

HYPOTHESIS

A minimally invasive treatment of acetabular T-type fractures is biomechanically equivalent to an open anterior plate osteosynthesis.

METHODS

Twenty-four synthetic hemipelvis specimens with a T-type acetabular fracture were divided in four groups. A posterior column screw was placed in every pelvis of every group. The anterior column was fixed with: - anterior column screw; - anterior column screw incl. INFIX; - INFIX alone; - 14-hole angular stable locking plate (standard fixation method). Displacement of the anterior column was reduced in group 2+3 using the INFIX. All specimens were cyclically loaded with 200N until a maximum of 600N. Movement/displacement of the fracture fragments were detected with a 3D-ultrasound measuring system. Displacement (mm) and Stiffness (N/mm) of the construction were analyzed.

RESULTS

Statistical assessment showed no significant differences between the four fixation types (p>0.05). The 14-whole locking plate (group 4) displayed the overall highest stability with a displacement of 1.3±0.04mm and stiffness of 76.3±2.4N/mm. Anterior screw fixation (group 1) proved to be the minimally invasive fixation method with the least displacement and highest stiffness (1.5±0.2mm, 68.3±6.8N/mm). The combination of an INFIX and an anterior column screw (group 2), showed a mean stiffness of 62.1±6.0N/mm and a mean displacement of 1.7±0.2mm. INFIX only (group 3) presented a displacement of 1.6±0.1mm and a stiffness of 64.5±4.5N/mm.

DISCUSSION

Minimally invasive fixation techniques for T-type acetabular fractures show promising biomechanical stability in non- or slightly displaced fractures. Furthermore, INFIX could be a feasible tool for the reduction of the anterior acetabular column.

LEVEL OF EVIDENCE

III, case control prospective experimental study.

Fixation Strategy Using Sequential Intraoperative Examination Under Anesthesia for Unstable Lateral Compression Pelvic Ring Injuries Reliably Predicts Union with Minimal Displacement

BACKGROUND

Examination under anesthesia (EUA) has been used to identify pelvic instability. Surgeons may utilize percutaneous methods for posterior and anterior pelvic ring stabilization. We developed an intraoperative strategy whereby posterior fixation is performed, with reassessment using sequential EUA to determine the need for anterior fixation. Our aim in the current study was to evaluate whether this strategy reliably results in union with minimal displacement.

METHODS

This was a multicenter retrospective study involving adult patients with closed lateral compression (LC) pelvic ring injuries treated during the period of 2013 to 2016. Included were patients who underwent percutaneous pelvic fixation based on sequential EUA. Data points included patient demographics, injury and fixation details, and displacement as observed on follow-up radiographs.

RESULTS

Complete documentation was available for 74 patients (mean age, 41 years). The mean duration of follow was 11 months. Fifty-three of the patients had LC-1 injuries, 19 had LC-2 injuries, and 2 had LC-3 injuries. Twenty-five (47.2%) of the 53 patients with LC-1 and 11 (57.9%) of the 19 patients with LC-2 injuries did not undergo anterior fixation on the basis of the algorithm. The 36 LC-1 or LC-2 patients who underwent combined anterior and posterior fixation had no measurable displacement at union. Of the 36 LC-1 or LC-2 patients with no anterior fixation, 27 with unilateral rami fractures had no measurable displacement at union. The remaining 9 LC-1 or LC-2 cases with no anterior fixation had bilateral superior and inferior rami fractures; each of these patients demonstrated displacement (mean, 7.5 mm; range, 5 to 12 mm) within 6 weeks of fixation that remained until union. All patients had protected weight-bearing for 12 weeks.

CONCLUSIONS

A fixation strategy based on sequential intraoperative EUA reliably results in union with minimal displacement for unstable LC pelvic ring injuries. Injuries requiring combined anterior and posterior fixation healed with no displacement. Those without anterior fixation and a unilateral ramus fracture healed with no displacement. In the presence of bilateral rami fractures, even with a negative finding on sequential EUA, the pelvis healed with 7.5 mm average displacement. Surgeons may consider anterior fixation to prevent this displacement.

LEVEL OF EVIDENCE

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

Effect of Deformity and Malunion of the Anterior Pelvic Ring

Pelvic fractures are common after high-energy trauma and are often associated with ligamentous injury. Treatment is guided by assessing stability of the pelvic ring, and unstable injuries frequently require surgery to achieve a desirable outcome. Assessment of pelvic ring stability is often possible with physical examination and standard imaging studies (plain radiographs and computed tomography); however, these "static" imaging modalities may not adequately identify dynamically unstable pelvic injuries that require surgery. Cadaveric and clinical data suggest that the injured pelvis may recoil significantly from the point of maximal displacement, and some unstable injuries may not be recognized until patients present with clinical symptoms. This article presents the case of a patient who sustained a minimally displaced pelvic ring injury that was stable on bedside examination and static imaging, but ultimately was unstable. She developed a substantial pelvic malunion with significant pain and activity limitations. The patient subsequently underwent successful pelvic ring reconstruction, and she remains asymptomatic at 2 years.

Pelvic post-traumatic asymmetry: Assessment and sequenced treatment

The most common cause of post-traumatic pelvic asymmetry is, by far, initial nonoperative treatment.

Open reduction and internal fixation of unstable pelvic fractures are recommended to avoid pelvic nonunion or subsequent structural deformities.

The most common symptom is pelvic pain. Pelvic instability is another symptom, as well as persistent urogenital problems and neurological sequelae.

Preoperative evaluation of these patients requires careful clinical and functional assessment, in addition to a complete radiological study.

Surgical treatment of pelvic fracture nonunions is technically demanding and has potentially serious complications.

We have developed a new classification that modifies and completes Mears and Velyvis’s classification in which we highlight two types of post-traumatic sequelae with different clinical conditions and whose basic differentiating element is whether pelvic deformity is present or not. Based on this classification, we have established our strategy of surgical treatment.

Cite this article: EFORT Open Rev 2018;3 DOI: 10.1302/2058-5241.3.170069.

Useful Intraoperative Technique for Percutaneous Stabilization of Bilateral Posterior Pelvic Ring Injuries

Treating patients with bilateral posterior pelvic ring injuries can be challenging. Placement of transiliac-transsacral style screws in available S1 or S2 osseous fixation pathways is becoming an increasingly common fixation method for these unstable injuries. We propose a percutaneous technique that sequences reduction and stabilization of 1 hemipelvis with at least 1 transiliac-transsacral screw and then uses the existing transiliac-transsacral screw and accompanying guide wires to assist in temporary stabilization and definitive fixation of the second hemipelvis.

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

OBJECTIVE

Recent clinical study suggests an advantage to adding an iliosacral screw to the anterior fixation construct for anteroposterior compression type-2 (OTA/AO type 61-B1), partially unstable open-book pelvic ring injuries. Others have described stress examination to determine any required supplemental fixation. However, biomechanical studies investigating iliosacral fixation requirements for this injury are lacking. Our objective was to determine whether adding an iliosacral screw to symphyseal plate fixation decreases displacement in a well-defined open-book pelvic ring injury model.

METHODS

An open-book pelvic ring injury was created in 10 human cadaveric pelves by unilaterally releasing the sacrospinous, sacrotuberous, and anterior sacroiliac ligaments plus transection of the pubic symphysis, approximating the classically described anteroposterior compression type-2 (APC-2) injury. Specimens were divided into 2 groups: (1) symphyseal plating and (2) plating plus an iliosacral screw. Using a standard bilateral stance model loaded at 550 N, displacement measurements were obtained at 210,000 and 500,000 cycles.

RESULTS

Three specimens failed before 210,000 cycles because of technical errors and were excluded from analysis. For the remaining 7, there was no significant difference in displacement between the 2 groups, and none sustained implant failure. Post hoc analysis showed that a large sample size (45/group) would be required to detect any difference with 80% power, indicating a small effect size with limited clinical application.

CONCLUSIONS

Adding an iliosacral screw to the symphyseal plate fixation does not provide improved biomechanical outcome in classically described APC-2 injuries. Clinically, stress examination may be useful to determine the need for supplemental posterior fixation in APC-2 injuries.

Percutaneous posterior fixation for unstable pelvic ring fractures

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

TYPE OF STUDY

Technical note, retrospective.

LEVEL OF EVIDENCE

IV.

Symphyseal fixation in open book injuries cannot fully compensate anterior SI joint injury-A biomechanical study in a two-leg alternating load model

INTRODUCTION

In open book injuries type Tile B1.1 or B1.2 also classified as APC II (anteroposterior compression), it remains controversial, if a fixation of the anterior ring provides sufficient stability or a fixation of the posterior ring should be included. Therefore the relative motion at the sacroiliac joint was quantified in a two-leg alternating load biomechanical pelvis model in the intact, the injured and the restored pelvis.

METHODS

Fresh-frozen intact (I) pelvises (n = 6) were subjected to a non-destructive cyclic test under sinosuidal axial two-leg alternating load with progressively increasing amplitude. Afterwards an open book injury (J) including the anterior ligament complex of the left sacroiliac joint, the sacrospinal and sacrotuberal ligaments (Tile B1.1) was created and the specimens were retested. Finally, the symphysis was stabilized with a modular fixation system (1-, 2- or 4-rod configuration) (R) and specimens were cyclically retested. Relative motion at the sacroiliac joint was captured at both sacroiliac joints by motion tracking system at two load levels of 170 N and 340 N during all tests.

RESULTS

Relative sacroiliac joint movements at both load levels were significantly higher in the J-state compared to the I-state, excluding superoinferior translational movement. With exception of the anteroposterior translational movement at 340N, the relative sacroiliac joint movements after each of the three reconstructions (1-, 2-, 4-rod fixation) were significantly smaller compared to the J-state and did not differ significantly to the I-state, but stayed above the values of the latter. Relative movements did not differ significantly in a direct comparison between the 1-rod, 2-rod and 4-rod fixations.

CONCLUSION

Symphyseal locked plating significantly reduces relative movement of the sacroiliac joint in open book injuries type Tile B1.1 or B1.2 (APC II) but cannot fully restore the situation of the intact sacroiliac joint.