Is fixation failure after plate fixation of the symphysis pubis clinically important?

Pubic symphysis tethering technique under endoscopic approach for treatment of pelvic open-book injury: A cadaver study

Purpose

Pubic symphysis disruption is common in pelvic trauma. Open reduction and internal fixation with a plate is the gold standard technique. Despite increasing interest in an endoscopic approach, the challenges of specific endoscopic instrumentation, reduction and fixation remains. In this feasibility cadaveric study, we aimed to describe a novel endoscopic technique of fixation of pubic symphysis disruption with a spinal vertebral tethering system.

Methods

Endoscopic pubic symphysis fixation with the tethering method was performed on a female cadaver specimen as well as an artificial pelvic model.

Results

We describe a step-by-step technique where three abdominal portals were utilized in order to insert screws in the pubic body and superior pubic ramus under endoscopic visualization. The synthetic tether ligament was introduced through a lateral portal and fixed and tensioned to reduce and compress the pubic symphysis.

Conclusions

While open plate fixation is the current gold standard of pubic symphysis disruption there is increasing interest in the minimally invasive endoscopic approach. In this feasibility cadaveric study, we present a new minimally invasive endoscopic fixation method to treat pubic symphysis disruption with a synthetic ligament.

Transobturator-cable-fixation in pelvic ring injuries with symphyseal disruption - a last resort?

PURPOSE

The role of transobturator-cable-fixation (TOCF) in traumatic symphyseal rupture of the pelvic ring remains unclear. This case series aims to evaluate TOCF in complex and revision cases in pelvic surgery.

METHODS

A retrospective analysis of a chronological case series was conducted, studying pelvic fractures stabilized using TOCF between January 2006 and December 2022. The variables considered included age, gender, fracture classification, Injury Severity Score (ISS), Body Mass Index (BMI), trauma mechanism, time to surgery, fixation technique, hospital duration, complications, status on discharge (Glasgow Outcome Scale; GOS), follow-up time and indication for the use of TOCF.

RESULTS

All patients (N = 7) were male with a mean age of 64 years and a mean BMI of 29. The mean ISS was 45, with the lowest ISS of 25, indicating that only polytraumatized patients were included. Two anterior-posterior-compression-, four lateral-compression-, and one vertical-shear-pelvic-injury were identified. TOCF was added in six cases to support symphyseal plating and in one case to external fixation. The mean hospital stay was 49 days and the mean follow-up duration was 8.5 months. No complications associated with TOCF were observed during the surgical procedure or follow-up.

CONCLUSION

TOCF showed no procedure-associated complications and effectively supported symphyseal healing in all cases. The main indications were obesity, poor bone quality in elderly patients, and revision cases. TOCF could be considered as a last treatment option in open-book pelvic injuries where plating or external fixation is at risk to fail.

Do we need another screw? Sacroiliac screw fixation in open-book pelvic ring injuries (APC type II)

Purpose

To compare anterior plate fixation (SP fixation) both alone and in combination with an additional posterior sacroiliac screw (SP+SIS fixation) as a treatment for pelvic ring injuries with widening of the pubic symphysis and disruption to the anterior sacroiliac ligaments.

Methods

To find studies with pelvic ring injuries (APC II; B2.3d) and SP or SP+SIS fixation, a systematic literature review was conducted by searching four databases. A protocol was published a priori at Open Science Framework (https://doi.org/10.17605/OSF.IO/3YHAV). Exclusion criteria included perineal injuries, chronic instability of the symphysis, complete sacroiliac separation, and pediatric patients (age <18 years). Primary outcomes of interest were defined as implant failure, health-related quality of life, and revision rate.

Results

Altogether, 1861 studies were screened, and 40 studies qualified for full-text analysis. In total, 14 studies (two surveys, six biomechanical studies, and six retrospective clinical studies) were included. The surveys revealed that surgeons who had more recently begun practicing were more likely to use posterior fixation (SP+ISS). The biomechanical studies were heterogenous and did not yield a uniform pattern. In clinical studies, 117 patients (45%) received SP fixation, and 142 patients (55%) received SP+SIS fixation. Complications occurred in 31 SP patients (30%) and in five SP+SIS patients (3.5%).

Conclusion

A high risk of bias was uncovered, and reporting was found to be incomplete. SP+SIS may have the potential to improve outcomes, but the evidence remains too inconclusive to draw reliable recommendations.

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.

A novel minimally invasive and press-fit method for symphysiodesis - a biomechanical analysis

PURPOSE

Does the cylindrical shaped bone block allow a stable construct for the arthrodesis of the pubic symphysis compared to a rectangular shaped bone block. The cylindrical shaped bone block stabilized by a 3.5 symphyseal plate is inferior to the stabilization with an internal fixator.

METHODS

This study analyzed the arthrodesis of the pubic symphysis on 24 synthetic pelvises, using a rectangular shaped bone block (control group) or a cylindrical shaped bone block, stabilized with a symphysis locking plate (n = 8) as the standard clinical procedure. Additionally we analyzed the stability using an internal fixator.

RESULTS

This study showed that utilizing a cylindrical shaped synthetic bone graft results in a significant higher contact area and compression force compared to the classical rectangular shaped graft. Furthermore, the stabilization with an internal fixator had the tendency for increases of compression force and contact area, yet without a statistical significance, when compared to the plate fixation.

CONCLUSION

The novel method of cylindrical symphysis resection and cylindrical bone block implantation allowed an increased biomechanical stability compared to using a classical rectangular bone graft, also resulting in higher contact area. Moreover, this technique would also allow a minimally invasive approach for this purpose, which in turn could preserve perisymphyseal ligaments, thereby improving healing in a clinical context.

Symphyseal plating for pelvic fracture in a morbidly obese patient: operative challenges and innovation of a novel 'wire-ramp plate-sliding method'

We are describing a case report of a morbidly obese patient (body mass index 41) in his mid-40s with Young and Burgess Anteroposterior Compression type II injury (AO Foundation/Orthopaedic Trauma Association type B1.2) managed by symphyseal plating. Morbid obesity made working at a depth very difficult; hence, we adopted a novel 'wire-ramp plate-sliding method'. In this method, two strong sturdy K-wires inserted through the medial-most plate holes into the pubis acted as a ramp over which the plate was pushed/slid distally. During this manoeuvre, the K-wires passing through the plate holes were used as a reduction tool. The patient also had a wedge fracture of the distal femoral shaft which was managed by retrograde femoral nailing. At 1-year follow-up, the pelvic continuity is maintained and the fracture has united. The patient is able to do full weight-bearing and is back to his normal life.

Advances in the Treatment of Implant-Associated Infections of the Pelvis: Eradication Rates, Recurrence of Infection, and Outcome

INTRODUCTION

Surgical site infections after operative stabilization of pelvic and acetabular fractures are rare but serious complications. The treatment of these infections involves additional surgical procedures, high health care costs, a prolonged stay, and often a worse outcome. In this study, we focused on the impact of the different causing bacteria, negative microbiological results with wound closure, and recurrence rates of patients with implant-associated infections after pelvic surgery.

MATERIAL AND METHODS

We retrospectively analyzed a study group of 43 patients with microbiologically proven surgical site infections (SSI) after surgery of the pelvic ring or the acetabulum treated in our clinic between 2009 and 2019. Epidemiological data, injury pattern, surgical approach, and microbiological data were analyzed and correlated with long-term follow-up and recurrence of infection.

RESULTS

Almost two thirds of the patients presented with polymicrobial infections, with staphylococci being the most common causing agents. An average of 5.7 (±5.4) surgical procedures were performed until definitive wound closure. Negative microbiological swabs at time of wound closure were only achieved in 9 patients (21%). Long-term follow-up revealed a recurrence of infection in only seven patients (16%) with an average interval between revision surgery and recurrence of 4.7 months. There was no significant difference of recurrence rate for the groups of patients with positive/negative microbiology in the last operative revision (71% vs. 78%). A positive trend for a correlation with recurrent infection was only found for patients with a Morel-Lavallée lesion due to run-over injuries (30% vs. 5%). Identified causing bacteria did not influence the outcome and rate of recurrence.

CONCLUSION

Recurrence rates after surgical revision of implant-associated infections of the pelvis and the acetabulum are low and neither the type of causing agent nor the microbiological status at the timepoint of wound closure has a significant impact on the recurrence rate.

The radiographic outcome after plating for pubic symphysis diastasis: does it matter clinically?

INTRODUCTION

Open reduction and internal fixation with plates is the most widespread surgery in traumatic pubic symphysis diastasis. However, implant failure or recurrent diastasis was commonly observed during follow-up. The aim of our study was to evaluate the radiologic findings and clinical outcomes.

MATERIALS AND METHODS

Sixty-five patients with traumatic pubic symphysis diastasis treated with plating between 2008 and 2019 were retrospectively reviewed. The exclusion criteria were a history of malignancy and age under 20 years. Radiographic outcomes were determined by radiograph findings, including pubic symphysis distance (PSD) and implant failure. Clinical outcomes were assessed according to the Majeed score at the final follow-up.

RESULTS

Twenty-eight patients were finally included. Nine patients (32%) experienced implant failure, including four (14%) with screw loosening and five (18%) with plate breakage. Only one patient underwent revision surgery. Postoperatively, a significant increase in PSD was observed at 3 months and 6 months. Postoperative PSD was not significantly different between patients with single plating and double plating, but it was significantly greater in the implant-failure group than in the non-failure group. The Majeed score was similar between patients with single plating and double plating or between the implant-failure group and the non-failure group. Body mass index, number of plates, age, and initial injured PSD were not significantly different between the implant-failure group and the non-failure group. Only a significant male predominance was observed in the implant-failure group.

CONCLUSION

A gradual increase in the symphysis distance and a high possibility of implant failure may be the distinguishing features of traumatic pubic symphysis diastasis fixation. The postoperative symphyseal distance achieved stability after 6 months, even after implant failure. Radiographic outcomes, such as increased symphysis distance, screw loosening, and plate breakage, did not affect clinical functional outcomes.

Quantification and visualization of anterior pelvis bone density to optimize screw fixation: A novel technique

Plate fixation of anterior pelvic ring fractures is often a vital component when surgically treating unstable pelvis fractures. Certain plate and screw configurations can have premature implant loosening, potentially in part due to insufficient pullout strength in lower density bone. This study sought to define densities about the anterior pelvic ring using a novel computer-based technique. Thirty-three patients who received a computed tomography (CT) of the abdomen/pelvis for reasons other than pelvis fracture in a 1-month time period were included. Three statistically distinct density regions of the anterior pelvis were identified based on the three-dimensional (3D) density map. The densest regions included both the anterior and posterior aspects of the superior pubic ramus, along with the region of bone along the inferior cotyloid fossa. The intermediate density region included the caudal and medial pubic body. The least dense region included the anterior aspect of the inferior pubic ramus (IPR), the posterior pubic body, and the posterior/inferior IPR. This study presents specific quantification of anterior pelvis bone density based on a novel technique using opportunistic CT scans. Clinical Significance: Anterior surgical fixation of unstable pelvic ring injuries may benefit from targeting areas of higher density as described in this novel technique.

Development and preclinical evaluation of a cable-clamp fixation device for a disrupted pubic symphysis

BACKGROUND

Traumatic separation of the pubic symphysis can destabilize the pelvis and require surgical fixation to reduce symphyseal gapping. The traditional approach involves open reduction and the implantation of a steel symphyseal plate (SP) on the pubic bone to hold the reposition. Despite its widespread use, SP-fixation is often associated with implant failure caused by screw loosening or breakage.

METHODS

To address the need for a more reliable surgical intervention, we developed and tested two titanium cable-clamp implants. The cable served as tensioning device while the clamp secured the cable to the bone. The first implant design included a steel cable anterior to the pubic symphysis to simplify its placement outside the pelvis, and the second design included a cable encircling the pubic symphysis to stabilize the anterior pelvic ring. Using highly reproducible synthetic bone models and a limited number of cadaver specimens, we performed a comprehensive biomechanical study of implant stability and evaluated surgical feasibility.

RESULTS

We were able to demonstrate that the cable-clamp implants provide stability equivalent to that of a traditional SP-fixation but without the same risks of implant failure. We also provide detailed ex vivo evaluations of the safety and feasibility of a trans-obturator surgical approach required for those kind of fixation.

CONCLUSION

We propose that the developed cable-clamp fixation devices may be of clinical value in treating pubic symphysis separation.

Clinical Experience with the New EASY (Endoscopic Approach to the Symphysis) Preparation Technique for Injuries of the Anterior Pelvic Ring

Background High-energy injuries of the anterior pelvic ring and especially disruptions of the pubic symphysis usually require surgical stabilization. There is a conflict between biomechanical stability and size in the surgical approach. We have previously presented a minimally invasive approach for symphyseal plating.

Methods Our current endoscopic surgical technique is presented step-by-step and is illustrated in a video. The results and courses of the first seven patients treated with the EASY preparation are presented.

Results In all seven patients, the EASY preparation was successful. In four of the seven patients with an anterior pelvic ring injury, we performed a complete endoscopic plate osteosynthesis of the pubic symphysis. One patient gave consent only for endoscopic preparation, in one patient, we converted to open plate due to ventilation problems, and in one patient, the superior pubic rami fracture was stable. There were no surgical complications.

Conclusion The EASY is a feasible minimally invasive preparation technique to stabilize anterior pelvic ring injuries in the most biomechanically stable manner by performing plate osteosynthesis. However, further scientific monitoring is necessary to improve the technique and validate our data.

Tape suture constructs for instabilities of the pubic symphysis: is the idea of motion preservation a suitable treatment option? A cadaver study

INTRODUCTION

Current gold standard for the treatment of symphyseal disruptions includes anterior plating, almost entirely prohibiting symphyseal mobility and resulting in an iatrogenic arthrodesis followed by high rates of implant failure. Minimally invasive tape suture constructs have been found to maintain the micro mobility of ligamentous injuries, yet still providing sufficient biomechanical stability. Recently, this technique has been primarily investigated for symphyseal disruptions on synthetic pelvic models. Therefore, the aim of this study was to examine the feasibility of this novel flexible osteosynthesis on cadaveric pelvic models based on the following hypothesis: tape suture constructs ensure sufficient biomechanical stability without inhibiting micro mobility of the pubic symphysis for the treatment of symphyseal disruptions and maintain stability during long-term loading.

MATERIALS AND METHODS

9 cadaveric anterior pelvic rings were used in this study and a symphyseal disruption was created in every specimen. The specimens were then exposed to short- and long-term vertical and horizontal cyclic loading after treatment with a tape suture construct in criss-cross technique. The mean maximum displacement (mm) during cyclic loading and the corresponding stiffness (N/mm) were measured and compared.

RESULTS

Regarding both displacement (mm) and corresponding stiffness (N/mm), the tape sutures displayed a significant difference between short- and long-term loading for cranial and caudal vertical loading (p < 0.01) but differences remained non-significant for horizontal loading (p > 0.05). No tape suture suffered from implant failure during long-term loading.

CONCLUSIONS

The tape suture construct displayed sufficient biomechanical stability without exceeding the physiological mobility of 2 mm of the pubic symphysis; however, also maintained the desired micro mobility of the affected joint necessary to prevent an iatrogenic arthrodesis. Further, all tape sutures maintained stability throughout long-term loading.

Biomechanical in vitro analysis of a novel flexible implant for pubic symphysis disruption using an ultra-high molecular weight polyethylene fiber cord

BACKGROUND

Plate osteosynthesis depicts the gold standard to surgically treat pubic symphysis disruptions. However, high rates of implant failure after plate osteosynthesis are reported, probably because of the iatrogenic arthrodesis of this fibrocartilaginous joint. Therefore, flexible implants for treatment of pubic symphysis disruptions appear to be a sensible solution.

METHODS

In this biomechanical screening study, we designed and investigated a flexible implant, which consists of two plates connected with an ultra-high molecular weight polyethylene fiber cord. We mechanically tested eye splices as a possible fixation method of the cords by performing tensile load to failure tests. Afterwards, we developed a biomechanically appropriate plate design and cord routing between the plates. Finally, we biomechanically tested the flexible implant under tensile and shear loading until failure.

FINDINGS

When fixing a 1 mm ultra-high molecular weight polyethylene fiber cord with eye splices, a load at failure of 1570.74 N was detected under tensile loading. None of the eye splices failed but the cords itself ruptured. The load at failure of the designed cord routing in criss-cross technique and fixation within the plates amounts 4742.09 N under tensile and 2699.77 N under shear load.

INTERPRETATION

We developed a novel flexible implant for repair of pubic symphysis disruptions using ultra-high molecular weight polyethylene fiber cords connected to osteosynthesis plates. We identified eye splices as a mechanically optimal fixation method and proved that the ultra-high molecular weight polyethylene fiber cord routing and fixation of the flexible implant clearly withstands physiological forces acting on the pubic symphysis.

Is unrestricted weight bearing immediately after fixation of rotationally unstable pelvic fractures safe?

INTRODUCTION

Rotationally unstable pelvic fractures treated with surgical fixation have traditionally been treated with restricted weight bearing on the affected side for 6-8 weeks post operatively. We have been developing pelvic fixation standards to allow for unrestricted weight bearing immediately post operatively in type B rotationally unstable pelvic fractures.

AIMS

To assess for safety and efficacy of allowing unrestrictive weight bearing in this cohort of patients, we have clinically and radiologically monitored outcomes up to two years post operatively.

METHODS

Through retrospective review, two cohorts of patients with Tile Type B pelvic fractures were identified that were treated at the Royal Adelaide Hospital, South Australia. Patient demographics, injury classification, surgical fixation and weight bearing status post operatively was recorded. One cohort of patients was allowed to fully weight bear post operatively, whilst the other was treated with 6 weeks of restricted post op weight bearing. At clinical follow up, post-operative x-rays were assessed for loss of reduction, screw or plate breakage and reoperation.

RESULTS

Between January 2018 and January 2021, 53 patients with rotationally unstable pelvic fractures that underwent surgical fixation were included in this study. One group of patents were allowed to immediately weight bear as tolerated (WBAT) post operatively (n = 28) and the other with restricted weightbearing (RWB) (n = 25). There was 1 re operation for failure of fixation in each group. Metalwork breakage was more common in the WBAT group than in the RWB group and this was seen only in APC fractures. This increase in metalwork failure was not associated with loss of reduction.

CONCLUSIONS

With surgical fixation, Tile type B rotationally unstable pelvic fractures can be allowed immediate weight bearing post operatively. We found this to be safe and effective, employing surgical strategies to address both anterior and posterior injuries to allow immediate unrestricted weight bearing. Broken metalwork was more commonly seen in the WBAT group but this was not associated with loss of reduction or reoperation.

Does augmentation increase the pull-out force of symphyseal screws? A biomechanical cadaver study

Purpose

Open reduction and internal fixation using anterior plate osteosynthesis currently represents the gold standard for the treatment of symphyseal disruptions. Since postoperative screw loosening with consequent implant failure is frequently observed, this study aims to evaluate if and to what extent augmentation can increase the pull-out force of symphyseal screws to improve the constructs stability.

Methods

Twelve human cadaveric anterior pelvic rings were separated at the symphyseal joint for bilateral testing, consequently achieving comparable sites. First, one non-augmented screw was drilled into the superior pubic ramus, whereas the contralateral side was primarily augmented. The screws were then withdrawn with a constant speed of 10 mm/min and the fixation strengths determined by the force (N) displacement (mm) curve. Finally, the primary non-augmented site was secondary augmented, representing revision surgery after initial implant failure, and the corresponding fixation strength was measured again.

Results

Augmentation compared to non-augmented screws displayed significantly higher pull-out forces with an increase in pull-out force by 377% for primary and 353% for secondary augmentation (p < 0.01). There was no significant difference in the pull-out force comparing primary and secondary augmentation (p = 0.74).

Conclusions

Primary and secondary augmentation significantly increases the stability of symphyseal screws and, therefore, potentially decreases rates of implant failure.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00068-022-01963-6.

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.

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).

Total endoscopic anterior pelvic approach (TAPA) - A new approach to the internal fixation of the symphysis

This study presents a detailed documentation of a total endoscopic anterior pelvic approach (TAPA) for plate fixation of a symphyseal disruption. The purpose of this work is to describe a minimally invasive technique as a possible method for reducing complications and hospitalization. Other goals included giving technical recommendations and assessing potential pitfalls and problems of this new surgical approach. Surgery was performed in an interdisciplinary setting by an experienced orthopaedic and general surgeon. The first endoscopic approach used to visualize the injury was the same as is used for endoscopic hernia surgery. The repositioning of the symphysial rupture was achieved either through external fixation or indirectly with traction and a pelvic binder. Plate positioning and fixation were achieved through two additional, minimally invasive incisions. The endoscopic approach shows multiple advantages, such as no detachment of the rectus abdominis muscle and smaller skin incisions. Furthermore, this approach could lessen the incidence of hernia and postoperative pain. We see the presented technique as a simple and innovative surgical method for treating symphyseal disruption.

Novel minimally invasive tape suture osteosynthesis for instabilities of the pubic symphysis: a biomechanical study

INTRODUCTION

Open book fractures are challenging injuries oftentimes requiring surgical treatment. The current treatment of choice is symphyseal plating, which requires extensive surgery and entirely limits physiological movement of the symphyseal joint, frequently resulting in implant failure. Therefore, we investigated the biomechanical properties of a semi-rigid implant (modified SpeedBridge^™) as a minimally invasive tape suture construct for the treatment of open book fractures and evaluated the superiority of two techniques of implementation: criss-cross vs. triangle technique.

MATERIALS AND METHODS

Nine synthetic symphyseal joints were dissected creating an open book fracture. The different osteosynthesis methods (plating, modified SpeedBridge^™ in criss-cross/triangle technique) were then applied. All constructs underwent horizontal and vertical loading, simulating biomechanical forces while sitting, standing and walking. For statistical analysis, dislocation (mm) and stiffness (N/mm) were calculated.

RESULTS

Symphyseal plating for the treatment of open book fractures proved to be a rigid osteosynthesis significantly limiting the physiological mobility of the symphyseal joint (dislocation: 0.08 ± 0.01 mm) compared to the tape sutures (dislocation: triangle technique 0.27 ± 0.07 mm, criss-cross technique 0.23 ± 0.05 mm) regarding horizontal tension (p < 0.01). Both modified SpeedBridge^™ techniques showed sufficient biomechanical stability without one being superior to the other (p > 0.05 in all directions). Considering vertical loading, no statistical difference was found between all osteosynthesis methods (caudal: p = 0.41; cranial: p = 0.61).

CONCLUSIONS

Symphyseal plating proved to be the osteosynthesis method with the highest rigidity. The modified SpeedBridge^™ as a semi-rigid suture construct provided statistically sufficient biomechanical stability while maintaining a minimum of symphyseal movement, consequently allowing ligamental healing of the injured joint without iatrogenic arthrodesis. Furthermore, both the criss-cross and the triangle technique displayed significant biomechanical stability without one method being superior.

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.

Trans-obturator cable fixation of open book pelvic injuries

Operative treatment of ruptured pubic symphysis by plating is often accompanied by complications. Trans-obturator cable fixation might be a more reliable technique; however, have not yet been tested for stabilization of ruptured pubic symphysis. This study compares symphyseal trans-obturator cable fixation versus plating through biomechanical testing and evaluates safety in a cadaver experiment. APC type II injuries were generated in synthetic pelvic models and subsequently separated into three different groups. The anterior pelvic ring was fixed using a four-hole steel plate in Group A, a stainless steel cable in Group B, and a titan band in Group C. Biomechanical testing was conducted by a single-leg-stance model using a material testing machine under physiological load levels. A cadaver study was carried out to analyze the trans-obturator surgical approach. Peak-to-peak displacement, total displacement, plastic deformation and stiffness revealed a tendency for higher stability for trans-obturator cable/band fixation but no statistical difference to plating was detected. The cadaver study revealed a safe zone for cable passage with sufficient distance to the obturator canal. Trans-obturator cable fixation has the potential to become an alternative for symphyseal fixation with less complications.

The role of anterior supra-acetabular external fixator as definitive treatment for anterior ring fixation in unstable pelvic fractures

PURPOSE

Management of anterior ring injuries is still a matter of discussion, and there are only few studies reporting anterior external fixator as definitive treatment for unstable pelvic injuries. This study aimed to describe the clinical and radiological outcomes of a consecutive series of mechanically unstable pelvic injuries that were treated with definitive anterior supra-acetabular external fixator for the anterior ring, and to identify risk factors for failure.

METHODS

We included a consecutive series of patients with unstable pelvic ring fractures who underwent anterior supra-acetabular external fixation for definitive treatment, between January 2012 and January 2020. All demographics, associated injuries and procedures, injury mechanism, and complications were analysed. Pelvic fracture was classified based on Orthopaedic Trauma Association/Tile AO (OTA/AO) and Young-Burgess classifications. Complications associated with the external fixator were revised. All patients were functionally evaluated at final follow-up and asked to report their clinical outcomes using the Majeed score.

RESULTS

A total of 47 patients were included, of which 25 were females. The median age was 44 years (interquartile range 23-59). Median follow-up duration was 14 months (interquartile range 6-31). The most frequent aetiology was motor vehicle accident (35), followed by fall from height (8). All fractures required posterior pelvic ring fixation. The median time during which patients had external fixation in situ was 11 weeks (interquartile range 9-13). All patients achieved healing of pelvic fracture at median time of 10 weeks (interquartile range 8-12). At final follow-up, the median displacement of the anterior pelvis was 6 mm (interquartile range 0-11). Superficial infection was the most common complication (n = 7). No washout procedures were needed. No major complication was reported. No patient required reoperation for anterior ring fracture. The median Majeed score was 88 points (range 60-95; interquartile range 80-90) at final follow-up.

CONCLUSION

Our findings suggest that the use of supra-acetabular external fixator is safe and effective for definitive treatment of the anterior ring in unstable pelvic fractures. It is a method with high proportion of excellent results, regardless of the type of fracture. The rate of complications is low, and it does not compromise functional results.

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.

Symphyseal plate with trans-symphyseal cross-screws for fixation of tile-type B1 pelvic ring injuries: radiological and functional evaluation

INTRODUCTION

Failure to neutralize the different physiological forces acting on the inferior as well as the superior regions of the pubic symphysis, the long healing time, is blamed for the repeated failures of conventional superior symphyseal plating.

MATERIAL AND METHODS

A three years prospective case series study between January 2017 and December 2019 was done, to evaluate the radiological and the functional outcomes, using Matta/Tornetta and Majeed criteria respectively, of the combination of trans-symphyseal cross-screws configuration and superior symphyseal plate in Tile-type B1 pelvic injuries.

RESULTS

Thirty patients, 18 with anteroposterior compression type II and 12 with type III, with a mean follow-up of 20 months ±5 were included. Radiologically, 26 (86.6%) cases showed an excellent, one (3.3%) good and three (10%) fair outcome. Clinically, excellent outcome in 26 (86.6%) cases, good in two (6.6%) cases, and fair in two (6.6%). Intra-operative drill bit breakage occurred in three (10%) cases and was the only reported technical complication. Significant re-displacement was reported in three (10%) cases.

CONCLUSION

The open trans-symphyseal cross-screws for fixation of the superior symphyseal plate is a simple, efficient, and safe technique with the biomechanical advantages of an extra-fixation point to the inferior symphysis together with a long and a strong bony anchorage.

A novel internal fixation method for open book injuries of the pubic symphysis- A biomechanical analysis

BACKGROUND

Pelvic fractures in adults are common injuries and account for up to 3.64% of all fractures. Usually, the treatment of open book injuries (Types B1.1 and B1.2 AO-Classification) is open reduction and plate stabilization using dynamic compression plates, with or without interlocking screws. These implants seem to enhance the outcome of such injuries, but also variety of complications occurs. To reduce complications and achieve appropriate reduction and stabilization, this study compared established stabilization techniques to a novel minimally invasive internal fixation method using an internal fixator system that is already being utilized for spinal fractures.

METHODS

This study was performed on 32 composite pelvises in a bilateral stance biomechanical model. The pelvises were variously stabilized with an internal fixator, a 4.5 mm dynamic compression plate and a 3.5 mm symphyseal locking dynamic compression plate. The contact area and loading forces were assessed by a sensor film inside the symphyseal gap.

FINDINGS

This study showed significantly greater reduction and loading capabilities of the internal fixator compared to the other implants (p < 0.05). There was also significantly greater contact area with the use of an internal fixator compared to the other implants (p < 0.05). The 3.5 mm interlocking plate showed significantly greater contact area compared to the 4.5 mm plate (p < 0.05).

INTERPRETATION

The internal fixator that is already proven in spinal surgery is biomechanically superior to conventional implants used in pelvic surgery. The contact area analysis furthermore showed a more physiological loading pattern, which can improve ligamentous healing in a clinical context.

Postpartum pubic symphysis diastasis-conservative and surgical treatment methods, incidence of complications: Two case reports and a review of the literature

BACKGROUND

Widening of the pubic joint of more than 10 mm is diagnostic and defined as pubic symphysis diastasis and is considered a complication of vaginal childbirth or pregnancy. As it is a rare pathology (ranging from 1 in 300 to 1 in 30000 pregnancies), no gold standard treatment has been defined.

CASE SUMMARY

This study examines two cases, a 27-year-old woman (gravida 1, para 1) and a 32-year-old woman (gravida 2, para 2), who presented to the clinic after uneventful vaginal deliveries. A normal pregnancy with no complications was observed in both patients. Severe pain in the pubic region occurred after labour and was accompanied by complicated locomotion. Pubic symphysis diastasis was confirmed radiologically and bed rest with lateral decubitus positioning was recommended. Oral non-steroidal antiinflammatory drugs were administered to relieve pain exacerbations. The symptoms decreased after treatment. Post-treatment magnetic resonance imaging (MRI) in the first case showed a reduction in symphyseal separation with no signs of osteitis. Three years later the symptoms recurred; MRI examination showed no further symphyseal widening or signs of osteitis. A relapse of symphyseal separation was diagnosed and conservative treatment was re-administered resulting in successful recovery. In the second case, pain recurred when the patient conceived for the second time. This time no benefit following conservative treatment was observed. Persistent pain and complicated locomotion led to scoliotic deformation of the lumbar part of the spine and leg length discrepancy, thus surgical treatment was chosen and internal pubic synthesis was performed.

CONCLUSION

Overall, surgical treatment resulting from insufficient conservative treatment showed a high risk of postoperative complications following the treatment of postpartum pubic symphysis diastasis.

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.

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.

Factors affecting mortality and reoperations in high-energy pelvic fractures

AIM

Factors affecting mortality during the first year following high-energy pelvic fractures has not been reported previously. Nor has surgical complications leading to reoperations been reported in a cohort with only high-energy pelvic trauma patients.

OBJECTIVES

The aim of this study was to report and analyse factors affecting outcome, in terms of mortality and reoperations, up to 1 year after the injury in patients with a traumatic pelvic ring injury due to a high-energy trauma.

MATERIALS AND METHODS

Data from the SweTrau (Swedish National Trauma Registry) on patients admitted to the Trauma Centre Karolinska in Stockholm, Sweden, were collected. Inclusion criteria were adults (age ≥ 18), trauma with a high-energy mechanism, alive on arrival, Swedish personal identification number, reported pelvic fracture on CT scan. Patient records and radiographies were reviewed. The study period was 2011-2015 with 1-year follow-up time. Univariate and regression analysis on factors affecting mortality was performed. Risk of reoperation was analysed using univariate and case-by-case analysis.

RESULTS

We included 385 cases with mean age 47.5 ± 20.6 years (38% females): 317 pelvic fractures, 48 acetabular fractures and 20 combined injuries. Thirty-day mortality was 8% (30/385), and 1-year mortality was 9% (36/385). The main cause of death at 1 year was traumatic brain injury (14/36) followed by high age (> 70) with extensive comorbidities (8/36). Intentional fall from high altitude (OR 6, CI 2-17), GCS < 8 (OR 12, CI 5-33) and age > 70 (OR 17, CI 6-51) were factors predicting mortality. Thirty patients (22%, 30/134) were further reoperated due to hardware-related (n = 18) or non-hardware-related complications (n = 12). Hardware-related complications included: mal-placed screws (n = 7), mal-placed plate (n = 1), implant failure (n = 6), or mechanical irritation from the implant (n = 4). Non-hardware-related reasons for reoperations were: infection (n = 10), skin necrosis (n = 1), or THR due to post-traumatic osteoarthritis (n = 1).

CONCLUSION

Non-survivors in our study died mainly because of traumatic brain injury or high age with extensive comorbidities. Most of the mortalities occurred early. Intentional injuries and especially intentional falls from high altitude had high mortality rate. Reoperation frequency was high, and several of the hardware-related complications could potentially have been avoided.

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.

Non-anatomic fixation for longstanding traumatic pubic diastasis using a bone graft: A report of two cases

The incidence of internal fixation failure of symphysis diastasis varies from 6% to 75%. Hardware breakage or migration and symphysis disruption recurrence are often asymptomatic and only in a few cases reoperation is required. This report describes the managements of two cases after failed internal fixation and neglected traumatic symphysis diastasis when it was technically impossible to achieve anatomical reduction of the anterior pelvic ring. Internal fixation and a bone graft for the symphysis without anatomical reposition were performed. Both of the patients achieved good results and had no complaints of pain during daily activities. Restoration of the anatomy should not be the aim in treating recurrence of the symphysis diastasis after failed fixation. The aim of the surgery was static fixation of the anterior pelvic ring with bone grafting.

Management of the open book APC II pelvis: Survey results from pelvic and acetabular surgeons in the United Kingdom

The results of this questionnaire show that the opinion of pelvic and acetabular surgeons in the UK and Republic of Ireland vary as to the best method of fixation for APC II pelvic injuries. A single anterior plate and single sacroiliac joint (SIJ) screw was the most popular fixation method, chosen by 34%. 74% favour a single, opposed to two orthogonal anterior plates. Posterior fixation supplementing anterior plating is preferred by 63% of surgeons, 58% use a single versus 42% two SIJ screws. Case by case assessment and intraoperative screening to assess stability is essential when considering whether to stabilise the SIJ.

Comparisons of front plate, percutaneous sacroiliac screws, and sacroiliac anterior papilionaceous plate in fixation of unstable pelvic fractures

BACKGROUND

This observational study was aimed at comparing the clinical efficacy of sacroiliac anterior plate fixation (SAPF), sacroiliac anterior papilionaceous plate (SAPP), and percutaneous sacroiliac screw internal fixation (PSCIF) introduced for patients with unstable pelvic fracture.

METHODS

Seventy-eight patients with unstable pelvic fracture (Tile type B or C) were recruited. Twenty-six patients underwent SAPF, 26 underwent SAPP, and 26 underwent PSCIF. Matta scores were calculated to evaluate the reduction of pelvic fractures, and Majeed scores were applied for the assessment of functional recoveries after surgery. Other perioperative clinical indicators were also recorded, including operation time, bleeding status, length of incision, ambulation time, fracture healing time, and incision infection.

RESULTS

Total operation time of PSCIF was remarkably shorter than that of SAPF and SAPP (P < .05), and the bleeding volume of SAPF and SAPP group was almost 26∼29 times as high as that of PSCIF group (P < .05). Besides, SAPP resulted in significant blood loss compared with SAPF (P < .05), while SAPF resulted in significantly larger operative incision length than SAPP and PSCIF (P < .05). Moreover, patients' stay time was prolonged in both SAPF and SAPP groups than in the PSCIF group (P < .05). Patients who received PSCIF exhibited significantly higher Matta and Majeed scores than those who received SAPF (all P < .05). Finally, SAPP was associated with fewer complications than SAPF, and complications were barely observed in the PSCIF group.

CONCLUSION

PSCIF may be more appropriate for patients with unstable pelvic fractures in comparison with SAPP and SAPF. Besides, SAPP is likely to be more efficacious than SAPF especially for Tile C patients.

Chronic Anterior Pelvic Instability: Diagnosis and Management

Chronic anterior pelvic ring instability can cause pain and disability. Pain typically is localized to the suprapubic area or inner thigh; often is associated with lower back or buttock pain; and may be exacerbated by activity, direct impact, or pelvic ring compression. Known etiologies of chronic anterior pelvic ring instability include pregnancy, parturition, trauma, insufficiency fractures, athletics, prior surgery, and osteitis pubis. Diagnosis often is delayed. Physical examination may reveal an antalgic or waddling gait, tenderness over the pubic bones or symphysis pubis, and pain with provocative maneuvers. AP pelvic radiographs may demonstrate chronic degenerative changes at the pubic symphysis or nonhealing fractures. Standing single leg stance (flamingo view) radiographs can demonstrate pathologic motion at the pubic symphysis. CT may be useful in assessing posterior pelvic ring involvement. The initial management is typically nonsurgical and may include the use of an orthosis, activity modification, medication, and physical therapy. If nonsurgical modalities are unsuccessful, surgery may be warranted, although little evidence exists to guide treatment. Surgical intervention may include internal fixation alone in select patients, the addition of bone graft to fixation, or symphyseal arthrodesis. In some patients, additional stabilization or arthrodesis of the posterior pelvic ring may be indicated.

Defining the pubic symphysis angle with respect to the coronal plane - Clinical and biomechanical considerations

BACKGROUND

Fixation strength of constructs placed across the pubic symphysis after injury is dependent on screw length, maximisation of which requires knowledge of the bony anatomy. The aim of this study was to describe the ideal angle of drilling to achieve maximal safe screw placement within the pubic body. Furthermore, the influences of age and gender on the skeletal topography were investigated.

METHODS

Three hundred CT scans of patients without pelvic injury were analysed to record the angle of the pubic body (APB) with respect to the coronal plane, and the depth of the pubic body (DPB) in the sagittal plane.

RESULTS

Mean APB and DPB were 54.69° and 55.35mm, respectively. Females had a significantly higher mean APB than males (57.29° vs. 52.41°; p<0.001), whereas males had a significant larger mean DPB (59.13mm vs. 51.03mm; p<0.001). Age had no effect on the mean APB. Mean width of the pubic body at the base was 9.38mm.

CONCLUSION

The anatomy of this region is reliable in terms of angles and sizes; a drill angle of 55° with respect to the operating table will allow maximal screw length, which should be in the region of 55mm. The mean width of the pubic body should allow for placement of a 3.5 or 4.5mm diameter screw.

Outcome of Internal Fixation and Corticocancellous Grafting of Symphysis Pubis Diastasis Which Developed after Malunion of Pubic Rami Fracture

We report a case of pubic symphysis diastasis, which was initially asymptomatic; however, it became symptomatic with urinary incontinence during pregnancy. The patient was treated with open reduction and internal fixation of the symphysis pubis. A corticocancellous autograft was used for filling the gap which remained despite bilateral compression of the iliac bones. We obtained satisfactory outcome in terms of symptoms at the 3 years' follow-up; however, there was instability findings in the X-rays with broken screws. We conclude that asymptomatic pubic symphysis diastasis might be symptomatic after additional trauma (such as pregnancy) in the following days, if it was unstable in the very beginning of injury. Fixation of old pubic symphysis diastasis with reconstruction plate by filling the gap by using corticocancellous autograft, might not prevent ultimate implant failure if the symphysis pubis diastasis is part of an unstable pelvic fracture in the very beginning.

Fractures of the pelvic ring

Traumatic disruptions of the pelvic ring are high energy life threatening injuries. Management represents a significant challenge, particularly in the acute setting in the presence of severe haemorrhage. Initial management is focused on preserving life by controlling haemorrhage and associated injuries. Advances in prehospital care, surgery, interventional radiology and the introduction of treatment algorithms to streamline decision making have improved patient survival. As more patients with unstable pelvic injuries survive, the poor results associated with nonoperative management and increasing patient expectations of outcome are making surgical management of these fractures increasingly common. The aim of operative fracture fixation is to correct deformity and restore function. The advent of percutaneous fixation techniques has reduced the morbidity previously associated with large operative exposures and internal fixation.

APC Injuries With Symphyseal Fixation: What Affects Outcome?

OBJECTIVE

To evaluate the influence of the symphyseal position at union, implant failure, and the type of posterior ring injury on validated outcome measures.

DESIGN

Retrospective review with prospectively collected validated outcome data.

SETTING

Two academic level 1 trauma centers.

PATIENTS/PARTICIPANTS

We evaluated 54 patients with operatively treated anterior-posterior compression (APC) type 2 and 3 injuries.

INTERVENTION

Thirty-five APC type 2 and 19 APC type 3 injuries were reviewed at a minimum of 2 years after surgery. Average follow-up was 7 years.

MAIN OUTCOME MEASURES

Patients were evaluated with validated EuroQol five dimensions (EQ5D), EuroQol health index, Visual Analog Score (VAS) pain, Majeed pelvic scores, and change in work status. The final anterior-posterior (AP) radiograph available was reviewed for implant failure and displacement. Revision surgery was documented based on implant status and displacement at final follow-up.

RESULTS

There were trends toward better outcomes for APC type 2 for EQ5D and VAS pain. Patients with injury severity score (ISS) >16 had worse reported health, Majeed scores, and VAS pain. Nineteen patients had failure of fixation. There were no differences in any outcome measure; trends toward better Majeed score were found for patients with intact fixation. Displacements >15 mm anteriorly at final follow-up negatively affect outcomes with significantly worse EQ5D, reported health, and Majeed score. Two patients required revision surgery. There were no differences in final outcomes.

CONCLUSIONS

No significant differences were found for APC type 2 versus type 3 injuries. Higher injury severity score resulted in worse outcomes and more pain. Outcomes were not effected by implant failure; however, major loss of reduction (>15 mm) anteriorly did negatively impact outcomes. Patients with failure who were revised to union did not have worse outcomes.

LEVEL OF EVIDENCE

Prognostic level IV. See Instructions for Authors for a complete description of levels of evidence.

Early failure of symphysis pubis plating

INTRODUCTION

Operative fixation of a disrupted symphysis pubis helps return alignment and stability to a traumatized pelvic ring. Implant loosening or failure has been demonstrated to commonly occur at some subacute point during the postoperative period. The purpose of this study is to report on a series of patients with traumatic pelvic ring disruptions to determine the incidence and common factors associated with early postoperative symphyseal plate failure before 7 weeks.

MATERIALS AND METHODS

126 patients retrospectively identified with unstable pelvic injuries treated with open reduction and plate fixation of the symphysis pubis and iliosacral screw fixation. Preoperative and postoperative radiographs, computed tomography (CT) images, and medical chart were reviewed to determine symphyseal displacement preoperatively and postoperatively, time until plate failure, patient symptoms and symphyseal displacement at failure, subsequent symphyseal displacement, incidence of additional surgery, and patient weight bearing compliance.

RESULTS

14 patients (11.1%) sustained premature postoperative fixation failure. 13 patients had anteroposterior compression (APC)-II injuries and 1 patient had an APC-III injury. Preoperative symphyseal displacement was 35.6 millimeters (mm) (20.8-52.9). Postoperative symphyseal space measurement was 6.3mm (4.7-9.3). Time until plate failure was 29days (5-47). Nine patients (64.2%) noted a pop surrounding the time of failure. Symphyseal space measurement at failure was 12.4mm (5.6-20.5). All patients demonstrated additional symphyseal displacement averaging 2.6mm (0.2-9.4). Two patients (14.2%) underwent revision. Four patients (28.5%) were non-compliant.

CONCLUSION

Premature failure of symphysis pubis plating is not uncommon. In this series, further symphyseal displacement after plate failure was not substantial. The presence of acute symphyseal plate failure alone may not be an absolute indication for revision surgery. Making patient education a priority could lead to decreased postoperative non-compliance and potentially a decreased incidence of implant failure. Posterior pelvic ring fixation aides overall pelvic ring stability and may help minimize further displacement after early postoperative symphyseal plate failure. Further functional outcome and biomechanical studies surrounding early symphyseal plate failure are needed.

The Effect of Implant Failure After Symphyseal Plating on Functional Outcome and General Health

OBJECTIVES

To relate the incidence of implant failure after internal anterior fixation of the pelvic ring to functional outcome and the health-related quality of life in patients.

DESIGN

Retrospective chart and radiographic review.

SETTING

Level I Trauma center.

METHODS

We retrospectively identified all patients who were treated with symphyseal plating for traumatic symphyseal diastasis between January 2003 and December 2013. Patients were asked to complete 2 questionnaires, the SF-36 and the Majeed score. A retrospective chart and radiographic control review were performed on all patients. The following data were collected: demographic data and details regarding the pelvic surgery. Computed tomograms were used to determine fracture classification and quality of reduction. Conventional radiographic follow-up were used to detect implant failure.

RESULTS

A total of 37 patients enrolled the study. Implant failure occurred in 11 (30%) patients resulting in the identification of 2 groups, "implant failure" (n = 11) and "intact implants" (n = 26). The baseline characteristics were equal in both groups. The analysis of the questionnaires revealed that the SF-36 score was not significantly different in any of the dimensions between the both groups. Patients in the implant failure group scored higher on all of the Majeed items, including the total Majeed score, but the difference did not reach statistical significance of P < 0.05.

CONCLUSIONS

Our study showed comparable results regarding the general health measured by the SF-36 for both groups and higher Majeed scores for patients with implant failure compared with patients with intact implants.

LEVEL OF EVIDENCE

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

A double-barrelled fibula graft restoring pelvic stability after late posterior ring instability related to a surgical treated osteitis pubis: a case report

BACKGROUND

Osteitis pubis or symphysitis pubis is a rare occurring non-infectious inflammation of the symphysis, the adjacent pubic bones and surrounding tissue. The therapy might be conservative or surgical by a resection of the symphysis and involved parts of the pubic bone. Nevertheless, this resection might lead to an anterior instability impairing the posterior arch and the sacroiliac joints in the aftermath.

CASE PRESENTATION

Here, we report about a 50-year-old women suffering from osteitis pubis treated by wedge resection of the symphysis and parts of the pubic bone. To maintain stability and for local antibiotic treatment a cement spacer was implemented. By clinical inconspicuous findings and the patient's desire, no further surgery was performed. However, 2 years after surgery the spacer dislocated and the patient complained about pain in the posterior arch due to an impaired mobility. Reconstruction surgery was planned including the bridging of the accrued space with a vascularized double-barrelled fibula graft, plate osteosynthesis and rectus abdominis flap coverage. The performed surgery led to pain relief and increased mobility.

CONCLUSION

The present case highlights the possible complication of surgical treated osteitis pubis leading to anterior arch instability affecting the posterior arch and thus impairing pelvic ring stability and patient mobility. Furthermore, we describe an opportunity to treat this complication or other etiologies contributing to anterior pelvic ring stability with large bone defects using a vascularized double-barrelled fibula graft to restore pelvic stability.

Comparison of Biomechanical Characteristics and Pelvic Ring Stability Using Different Fixation Methods to Treat Pubic Symphysis Diastasis: A Finite Element Study

The intention of this study was to compare the biomechanical characteristics using 5 internal fixation methods used clinically to stabilize a pubic symphysis diastasis (PSD, Tile type B1).A 3-dimensional finite element model of PSD was simulated using 5 implants, including single superior plate (Single-Plate), superior and anterior plate (Dual-Plate), single cannulated screw (Single-Screw), crossed dual cannulated screws (Cross-Screw), and parallel dual cannulated screws (Para-Screw). Three loads were distributed in all models, including dual-leg standing, single-leg stance, and rotation. To evaluate the biomechanical properties, the construct stiffness, the stress distribution, and the von Misses stress were recorded and analyzed. To evaluate pelvic ring stability, the micromotion of the pubic symphysis and iliosacral joint was analyzed.Disruption of pubic symphysis dramatically decreased the pelvic ring stability. Cross-screw and Para-Screw showed higher stiffness than other methods. All implants endured the maximum von Misses stress under single-leg stance. For Plate-Screw system, the maximum stress occurred at a place where it strides over pubic symphysis and adjacent Plate-Screw interface. The single implant and Para-Screw had a tendency to fail. Para-Screw showed the best fixation effect under dual-leg conditions. Cross-screw showed superior antishearing force capacity under single-leg stance. Dual-Plate provided maximum antihorizontal rotation. Para-Screw provided the maximum stabilization for the posterior pelvic ring.This study showed the biomechanical advantages of dual-implant for PSD only from the finite element view. The Para-Screw provided high construct stiffness under 3 load conditions. The single implant and Para-Screw had a tendency to fail. The better anterior and posterior pelvic stabilization were obtained by the dual-implant fixation than other methods. Therefore, the Cross-Screw and Dual-Plate fixation methods should be preferred in the treatment of pubic symphysis from the finite element view.

Influence of flexible fixation for open book injury after pelvic trauma--a biomechanical study

BACKGROUND

Implant loosening is frequently detected after fixation of open book injuries. Though many authors do not see this as a complication, it is often the reason for hardware removal or reinstrumentation in the case of remaining instability. We hypothesized that the flexibility of the implant has an influence on loosening and thus on failure of the construct.

METHODS

We used 6 fresh-frozen pelvic specimens and tested them with our recently introduced test setup for two-leg alternate loading. We subjected them to a non-destructive quasi-static test in the intact condition followed by a non-destructive cyclic test under axial sinusoidal loading with progressive amplitude. Afterwards we simulated an open book injury and performed fixation with three different configurations of a modular fixation system (1-, 2- or 4-rod configuration) in randomized order. Subsequently, the specimens were subjected to 3 cyclic tests with the same loading protocol as previously defined. Finally, each construct was cyclically tested to failure keeping the final rod configuration.

FINDINGS

We detected significantly greater mobility after 1-rod-fixation and no significant differences after 2-rod or 4-rod-fixation compared to the intact symphysis condition. In the destructive test series the 4-rod-fixation failed first followed by the 1-rod-fixation. The 2-rod-fixation sustained almost 3 times as many load cycles prior to failure as the 4-rod-fixation, whereas the 1-rod-fixation sustained twice as many cycles as the 4-rod-fixation.

INTERPRETATION

In conclusion, flexible fixation of the ruptured pubic symphysis in human specimens shows superior behavior with respect to load bearing capacity and ability to withstand cyclic loading compared to stiff constructs.

Locked versus standard unlocked plating of the symphysis pubis in a Type-C pelvic injury: a cadaver biomechanical study

INTRODUCTION

The benefits of locked plating for pubic symphyseal disruption have not been established. The purpose of this biomechanical study was to determine whether locked plating offers any advantage over conventional unlocked plating of the pubic symphysis in the vertically unstable, Type-C pelvic injury.

METHODS

In each of eight embalmed cadaver pelvis specimens, sectioning of the pubic symphysis in conjunction with a unilateral release of the sacroiliac, sacrospinous, and sacrotuberous ligaments and pelvic floor was performed to simulate a vertically unstable Type-C (Orthopaedic Trauma Association 61-C1.2) pelvic injury. The disrupted SI joint was then reduced and fixed using two 6.5mm cannulated screws inserted into the S1 body. Using a six-hole 3.5mm plate specifically designed for the symphysis pubis having both locked and unlocked capability, four pelvises were fixed with locked screws and four pelvises were fixed with standard unlocked bicortical screws. Both groups were similar based on a dual-emission X-ray absorptiometry evaluation (P=0.69). Each pelvis was then mounted on a servohydraulic materials-testing apparatus using a bilateral stance model to mainly stress the symphyseal fixation and was cycled up to 1 million cycles or failure, whichever occurred first.

RESULTS

Five specimens experienced failure at the jig mounting/S1 vertebral body interface, occurring between 360,000 and 715,000 cycles. Frank failure of the anterior or posterior instrumentation did not occur. However, end-trialing diastasis of the initial pubic symphysis reduction was found in all pelvises. There were no differences between the groups with respect to this loss of symphyseal reduction (P=0.69) or average cycles to failure (P=1.0).

CONCLUSION

Pubic symphyseal locked plating does not appear to offer any advantage over standard unlocked plating for a Type-C (OTA 61-C1.2) pelvic ring injury.