Displacement After Simulated Pelvic Ring Injuries: A Cadaveric Model of Recoil

Does sequential examination under anaesthesia provide a reliable method to determine a management plan for unstable lateral compression pelvic ring injuries? a prospective study

PURPOSE

To assess the reliability of sequential examination under anaesthesia (EUA) to determine pelvic instability and to evaluate radiological and functional outcomes in unstable lateral compression (LC) injuries.

METHODS

A prospective case series study was conducted from 2020 to 2022 at a university hospital on 43 cases with LC injuries that met the inclusion criteria. Sequential EUA was carried out in three steps. Posterior-only fixation or anterior-posterior fixation was done according to the algorithm. Each patient was followed up for at least 12 months, both radiologically and functionally.

RESULTS

Forty cases proved unstable and were fixed. None showed secondary displacement in the anterior-posterior fixation group. However, five cases (19.2%) of the posterior-only fixation group showed secondary displacement with a mean of 5.9 mm. Four cases of them had tetra-ramic injuries. There is a high tendency for secondary displacement at 14.5 mm or more preoperative displacement of the rami. Patients with secondary displacement showed comparable functional outcome scores to patients without secondary displacement. Posterior-only fixation showed shorter operative time, lesser radiological exposure, blood loss and iatrogenic nerve injury than anterior-posterior fixation.

CONCLUSION

EUA is a reliable method to determine pelvic instability and management plan for LC fractures with unilateral anterior ring injury. Anterior-posterior fixation is needed if there is a tetra-ramic fracture or initial anterior ring displacement of 14.5 mm or more, irrespective of EUA.

The EMS stress view: occult pelvic instability revealed by pre-hospital pelvic binder placement

PURPOSE

To describe and evaluate the serendipitous pelvic binder stress radiographs of lateral compression type (LC) pelvic ring injuries.

METHODS

This was a retrospective case series performed at a single, level I academic trauma center from 2016 to 2018. All patients presenting with a minimally displaced LC pelvic ring injury were reviewed (< 10 cm displacement on static pelvic radiographs). Patients with X-rays (XR) in a pelvic binder (EMS stress) and with the pelvic binder removed were included. Pelvic ring stability was determined by attending surgeon evaluation of EMS stress radiographs versus static XR of the pelvis. Patients were treated non-operatively and allowed to weight bear or taken to the operating room for exam under anesthesia (EUA) and potential operative fixation. Clinical success of treatment was determined by evaluation of further displacement at the completion of their most recent follow-up.

RESULTS

Thirty-seven patients of the initial 398 reviewed met inclusion criteria. Fourteen of 37 patients (38%) were categorized as stable with no significant pelvis displacement seen on EMS stress and were treated non-operatively without further sequelae (4.6 months mean follow-up). The remaining 23/37 (62%) were treated operatively. Occult instability was identified on EMS stress in 14 (61%) of those 23 patients and the remainder were determined to be unstable based upon fracture pattern or EUA. All patients went on to successful treatment without significant pelvic deformity (7.8 months mean follow-up).

CONCLUSION

The EMS stress XR is a valuable, opportunistic evaluation in LC pelvic ring injuries. This evaluation is a useful diagnostic adjunct to alert the provider that additional stress imaging may be indicated to evaluate for occult pelvic ring instability.

Comparing Emergency Department Stress of Lateral Compression Type 1 Pelvis Fractures With a Validated Instability Scoring System

INTRODUCTION

Lateral compression type 1 (LC1) pelvic ring injuries represent a heterogeneous group of fractures with controversial surgical indications. Recently, multiple institutions have suggested the safety and reliability of an emergency department (ED) stress to evaluate for occult instability. The purpose of this study was to correlate ED stress examination of LC1 pelvis fractures against a validated fracture instability scoring system.

METHODS

This was a retrospective review of a consecutive series of 70 patients presenting with minimally displaced LC1 fractures at a level 1 academic trauma center. All patients were stressed in the ED radiology suite, and displacement was measured by comparing calibrated stress radiographs with static radiographs (>10 mm displacement defined positivity). ED stress results were compared with radiographic scores assigned according to the validated Beckmann scoring system (score <7: stable-nonsurgical recommendation; score 7 to 9: indeterminant recommendation; and score >9: unstable-surgical recommendation).

RESULTS

Thirteen patients had a positive ED stress examination, and 57 patients stressed negative. The mean displacement was significantly different between the three groups (Beckmann 5 to 6: 3.31 mm, SD = 2.4; Beckmann 7 to 9: 4.23 mm, SD = 3.2; Beckmann 10+: 12.1 mm, SD = 8.6; P < 0.001). Zero of 18 patients in the stable group stressed positive, and only 3 of 38 patients in the indeterminant group stressed positive (7.9%). Finally, 10 of 14 patients in the unstable group stressed positive (71.4%; P < 0.001). Sacral displacement (P = 0.001), superior ramus location (P < 0.02), and sacral columns (P < 0.001) significantly predicted ED stress positivity in multivariate analysis.

CONCLUSIONS

Comparison of a validated instability scoring system with ED stress examination of minimally displaced LC1 fractures in awake and hemodynamically stable patients showed excellent correlation. This suggests that the ED stress examination is a useful diagnostic adjunct. LC1 fracture characteristics should be analyzed to determine which pelvic fracture characteristics determine occult instability before stress examination.

LEVEL OF EVIDENCE

Level III diagnostic.

Atypical APC-1 pelvic fracture presenting with pelvic instability: successful management with pubic symphysis fusion

By definition, anteroposterior (AP) compression type 1 (APC-1) injury is a type of pelvic ring injury, which is widely acknowledged as 'stable'. Unstable forms of this injury are very rare and present a challenge for diagnosis and clinical management. Detailed herein is a man in his early 30s, referred to our institution with a 2-year history of pubic symphysis pain following a road traffic accident. Radiological investigation revealed an unstable APC-1 injury. This was subsequently managed with surgical reconstruction leading to the successful return of the patient to former function and recreational activities.

Revisiting Non-operative Treatment of Lateral Compression Pelvic Fractures, Analysis of Rehabilitation, and Radiologic Outcomes in a Historical Cohort Using Today's Association of Osteosynthesis (AO) Stability Criteria

BACKGROUND

Type I lateral compression pelvic fractures (LC-I) have historically been treated conservatively. Inferior outcomes in a distinctive subset of these injuries have been reported, therefore their management has shifted towards surgery. Revisiting the historical series of LC-I allows us to determine whether non-operative management of these unstable patterns results in poorer outcomes. The objective was to evaluate the differences in the rehabilitation progress, fracture consolidation, and displacement in non-operatively treated LC-I fractures that would be considered unstable using today's Association of Osteosynthesis (AO) criteria.

METHODS

We conducted a retrospective review of conservatively treated LC-I injuries in a single-level I trauma center between June 2010 and June 2014. Patients were distributed in stable (group A) and unstable (group B) groups according to the 2018 AO classification. Time to walk independently (TWI), time to return to work (TRW), fracture consolidation, and displacement were analyzed.

RESULTS

34 patients, mean age of 45.5 ±14.5 years, were included. Mean TWI in groups A and B were 71.2 ±31.9 and 105.9 ±50.9 days (p=0.027). Mean TRW was 106 ±51.3 and 157 ±84 days in groups A and B, respectively (p=0.038). A difference in mean TWI and TRW of 34.7 and 51.3 days between groups was observed. No significant differences in fracture consolidation or displacement were observed.

CONCLUSION

Unstable fractures presented significantly longer TWI and TRW. The revised AO classification contributes to the identification of fracture patterns that correlate with prolonged rehabilitation in which additional treatment strategies might be considered.

Management and outcomes of open pelvic fractures: An update

BACKGROUND

Open pelvic fractures remain challenging in terms of their management. The purpose of this narrative review was to evaluate the latest advances made in the management of these injuries and report on their clinical outcome.

PATIENTS AND METHODS

A literature review was undertaken focusing on studies that have been published on the management of open pelvic fractures between January 2005 and November 2019. Information extracted from each article include demographics, mechanism of injury, injury severity score (ISS), classification of pelvic ring fracture, classification of open soft tissue, specific injury zone classification, number of cases with hemodynamic instability, number of cases that received blood transfusions, amount of packed red blood cells transfused during the first 24 h, number of cases with anorectal trauma, urogenital injury, number of fecal diversional colostomies and laparotomies, angiographies and embolization, preperitoneal pelvic packings, length of stay in intensive care unit (ICU) and in hospital, and mortality.

RESULTS

Fifteen articles with 646 cases formed the basis of this review. The majority of patients were male adults (74.9%). The mean age was 35.1 years. The main mechanism of injury was road traffic accidents, accounting for 67.1% of the injuries. The mean ISS was 26.8. A mean of 13.5 units of PRBCs were administered the first 24 h. During the whole hospital stay, 79.3% of the patients required blood transfusions. Angiography and pelvic packing were performed in a range of 3%-44% and 13.3%-100% respectively. Unstable types of pelvic injuries were the majority (72%), whilst 32.7% of the cases were associated with anorectal trauma, and 32.6% presented with urogenital injuries. Bladder ruptures were the most reported urogenital injury. Fecal diversional colostomy was performed in 37.4% of the cases. The mean length of ICU stay was 12.5 days and the mean length of hospital stay was 53.0 days. The mean mortality rate was 23.7%.

CONCLUSION

Mortality following open pelvic fracture remains high despite the evolution of trauma management the last 2 decades. Sufficient blood transfusion, bleeding control, treatments of associated injuries, fracture fixation and soft tissue management remain essential for the reduction of mortality and improved outcomes.

Lateral compression type 1 (LC1) pelvic ring injuries: a spectrum of fracture types and treatment algorithms

Lateral compression type 1 (LC1) fractures are the commonest pelvic ring injury. However, they represent a heterogenous spectrum of injury mechanisms and fracture patterns, resulting in a lack of strong evidence for a universally agreed treatment algorithm. Although consensus exists that LC1 fractures have a preserved posterior ligamentous complex and are vertically stable, controversy persists around defining internal rotational instability. As such, treatment strategies extend from routine non-operative management through to dynamic imaging such as examination under anaesthetic (EUA) or stress radiographs to guide fixation algorithm. Multiple protocols sit between these two, all with slightly different thresholds for advocating surgery or otherwise, exemplifying a broad lack of consensus that is not seen for other, more severe, grades of pelvic ring injury. In the following review we discuss the evolving concepts of pelvic ring instability and management, starting from a historical perspective, through to current trends and controversies in LC1 fracture treatment. Emerging directions for research and emerging pharmacological and surgical treatments/technologies are also considered and expert commentary from 3 leading centres provided. The distinction is made between LC1 fracture arising from high-energy trauma and those following low-energy falls from standing height (so-called fragility fractures of the pelvis-FFP), since these two patient groups have different functional requirements and medical vulnerabilities. Issues pertaining to FFP are considered separately.

Integrity of the pectineal ligament in MRI correlates with radiographic superior pubic ramus fracture displacement

BACKGROUND

Estimating the stability of pelvic lateral compression fractures solely by static radiographs can be difficult. In this context, the role of anterior pelvic soft tissues as potential secondary stabilizer of the pelvic ring has hardly been investigated.

PURPOSE

To correlate the initial radiographic appearance of the pubic ramus fracture with the integrity of the pectineal ligament, a strong ligament along the pecten pubis.

MATERIAL AND METHODS

In total, 31 patients with a pelvic lateral compression fracture (AO/OTA 61- B1.1/B2.1) with 33 superior pubic ramus fractures and available post-traumatic radiographs (pelvis anteroposterior, inlet, outlet) and magnetic resonance imaging (MRI) of the pelvis with fat-suppressed coronal images were reviewed retrospectively. Radiographic superior pubic ramus fracture displacement was measured and correlated to the degree of MR-morphologic alterations of the pectineal ligament (grade 0 = intact, grade 3 = rupture).

RESULTS

In the majority of fractures (72.7%), associated MR-morphologic alterations of the pectineal ligament were present. Radiographic displacement and MRI grading showed a strong positive correlation (Spearman rho = 0.783, P < 0.001). The sensitivity and specificity for a radiographic displacement of >3 mm on plain radiographs to detect a structural ligament lesion on MRI (grade 2 and higher) were 73% and 100%, respectively.

CONCLUSION

Radiographic displacement of superior pubic ramus fractures >3 mm is a strong indicator for a structural lesion of the pectineal ligament. Future studies should investigate the potential biomechanical importance of this ligament for pelvic ring stability.

The Utility of Obtaining Postmobilization Imaging in Nonsurgical Pelvic Ring Injuries

INTRODUCTION

Pelvic fractures are diverse injuries with varying degrees of severity. Treatment recommendations are determined by the associated instability. For likely stable patterns, postmobilization imaging is used to assess for occult instability. This study assesses the utility of postmobilization images and determines how often they alter the recommendations for treatment.

METHODS

Records at a single level 1 trauma center from January 2007 through December 2014 were reviewed, and patients with Current Procedural Terminology codes and International Classification of Diseases, Ninth Revision codes for pelvic and acetabular fractures were identified. For those chosen for nonsurgical treatment at presentation, a detailed chart review was performed to identify patients who had postmobilization radiographs and to determine whether this imaging led to a change in treatment recommendations.

RESULTS

Inclusion criteria were met by 762 patients whose average age was 50 years. Of 331 patients planned for nonsurgical treatment at presentation, 168 (51%) had postmobilization images. The postmobilization radiographs did not alter treatment recommendations in any of these patients; however, three of these patients underwent surgical stabilization based on the patients' report of pain with attempted mobilization.

DISCUSSION

Routine postmobilization imaging has limited value for patients with pelvic injuries and a low likelihood for instability, such as those with incomplete sacral fractures. Eliminating this step would reduce cost and decrease radiation exposure. The need for change in treatment plan or further imaging should be based on the patient's clinical progress with weight bearing.

LEVEL OF EVIDENCE

Level 4.

High-energy Lateral Compression Type 1 Injuries of the Pelvis: A Spectrum of Injury

Lateral compression type 1 pelvic fractures comprise a spectrum of injuries of varying stability. The clinician should be cognizant of signs and symptoms of instability including complete sacral fractures, bilateral ramus fractures, displacement greater than 1 cm, high-energy mechanism, and inability to bear weight. Management of these injuries is controversial, but the clinician should consider examination under anesthesia and potentially surgical stabilization.

Radiological measurement of pelvic fractures using a pelvic deformity measurement software program

BACKGROUND

It is difficult for the surgeon to measure pelvic displacement in the closed reduction operation for unstable pelvic fracture. We therefore developed a pelvic deformity measurement software program based on standardized radiographs. The objectives of the present study were to evaluate the inter-observer reliability of the program for measuring specific fracture types on preoperative pelvic films and to assess the validity of the measurement software program by comparing it with a gold standard.

METHODS

Twenty-five patients diagnosed with AO/OTA type B or C pelvic fractures with the unilateral pelvis fractured and dislocated were included in this study. Four separate observers repeatedly determined the translational and rotational patterns and outcomes using the software program and hand measurement, and calculated the displacement using computed tomography (CT) coupled with a three-dimensional (3D) CT model. The validity of the measurement software was calculated by assessing the consistency between the software measurements and the gold standard. Additionally, inter-observer reliability was assessed for the software. The software was also applied in preliminary clinical practice for closed reduction procedures.

RESULTS

The overall inter-observer reliabilities of the software program, CT coupled with 3D reconstruction, and hand measurements were high, with kappa values of 0.956, 0.958, and 0.853, respectively. The software showed validity similar to that of CT coupled with 3D reconstruction (0.939 vs. 0.969), and better than that of hand measurement (0.939 vs. 0.858). A preliminary clinical application demonstrated that the software is effective for guiding closed reduction of pelvic fractures.

CONCLUSIONS

Our newly established pelvic deformity measurement program is a reliable and accurate tool for analyzing pelvic displacement patterns and can be used for guidance of closed reduction and planning of the reduction pathway.

LEVEL OF EVIDENCE

III.

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.

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.

Kendrick's extrication device and unstable pelvic fractures: Should a trochanteric belt be added? A cadaveric study

INTRODUCTION

Pre-hospital pelvic stabilisation is advised to prevent exsanguination in patients with unstable pelvic fractures (UPFs). Kendrick's extrication device (KED) is commonly used to extricate patients from cars or crevasses. However the KED has not been tested for potential adverse effects in patients with pelvic fractures. The aim of this study was to examine the effect of the KED on pubic symphysis diastasis (SyD) with and without the use of a trochanteric belt (TB) during the extraction process following a MVC.

MATERIALS AND METHODS

Left-sided "open-book" UPFs were created in 18 human cadavers that were placed in seven different positions simulating pre-extraction and extraction positions using the KED with and without a TB in two different positions (through and over the thigh straps). The SyD was measured using anteroposterior radiographs. The effects of the KED with and without TB, on the SyD, were evaluated.

RESULTS

The KED alone resulted in a non-significant increase of the SyD compared to baseline, whereas the addition of a TB to the KED resulted in a significant reduction of the SyD (p<0.001). The TB through the straps provided a significantly better reduction than the TB over the straps in the extracted position (p<0.05).

CONCLUSION

Our study demonstrated that a TB in combination with the KED on UPFs is an effective way to achieve early reduction. The addition of the TB in combination with the KED could be considered for Pre-Hospital Trauma Life Support (PHTLS) training protocols.

Assessment of Lateral Compression type 1 pelvic ring injuries by intraoperative manipulation: which fracture pattern is unstable?

PURPOSE

We performed a prospective study to document, by intra-operative manipulation under anaesthesia (MUA) of the pelvic ring, the stability of lateral compression type 1 injuries that were managed in a Level-I Trauma Centre. The documentation of the short-term outcome of the management of these injuries was our secondary aim.

METHODS

A total of 63 patients were included in the study. Thirty-five patients (group A) were treated surgically whereas 28 (group B) were managed nonoperatively. Intraoperative rotational instability, evident by more than two centimetres of translation during the manipulation manoeuvre, was combined with a complete sacral fracture in all cases.

RESULTS

A statistically significant difference was present between the length of hospital stay, the time to independent pain-free mobilisation, post-manipulation pain levels and opioid requirements between the two groups, with group A demonstrating significantly decreased values in all these four variables (p < 0.05). There was also a significant difference between the pre- and 72-hour post-manipulation visual analogue scale and analgesic requirements of the group A patients, whereas the patients in group B did not demonstrate such a difference.

CONCLUSION

LC-1 injuries with a complete posterior sacral injury are inheritably rotationally unstable and patients presenting with these fracture patterns definitely gain benefit from surgical stabilisation.

Comparison of three different pelvic circumferential compression devices: a biomechanical cadaver study

BACKGROUND

Pelvic circumferential compression devices are designed to stabilize the pelvic ring and reduce the volume of the pelvis following trauma. It is uncertain whether pelvic circumferential compression devices can be safely applied for all types of pelvic fractures because the effects of the devices on the reduction of fracture fragments are unknown. The aim of this study was to compare the effects of circumferential compression devices on the dynamic realignment and final reduction of the pelvic fractures as a measure of the quality of reduction.

METHODS

Three circumferential compression devices were evaluated: the Pelvic Binder, the SAM Sling, and the T-POD. In sixteen cadavers, four fracture types were generated according to the Tile classification system. Infrared retroreflective markers were fixed in the different fracture fragments of each pelvis. The circumferential compression device was applied sequentially in a randomized order with gradually increasing forces applied. Fracture fragment movement was studied with use of a three-dimensional infrared video system. Dynamic realignment and final reduction of the fracture fragments during closure of the circumferential compression devices were determined. A factorial repeated-measures analysis of variance with pairwise post hoc comparisons was performed to analyze the differences in pulling force between the circumferential compression devices.

RESULTS

In the partially stable and unstable (Tile type-B and C) pelvic fractures, all circumferential compression devices accomplished closure of the pelvic ring and consequently reduced the pelvic volume. No adverse fracture displacement (>5 mm) was observed in these fracture types. The required pulling force to attain complete reduction at the symphysis pubis varied substantially among the three different circumferential compression devices, with a mean (and standard error of the mean) of 43 ± 7 N for the T-POD, 60 ± 9 N for the Pelvic Binder, and 112 ± 10 N for the SAM Sling.

CONCLUSIONS

The Pelvic Binder, SAM Sling, and T-POD provided sufficient reduction in partially stable and unstable (Tile type-B1 and C) pelvic fractures. No undesirable overreduction was noted. The pulling force that was needed to attain complete reduction of the fracture parts varied significantly among the three devices, with the T-POD requiring the lowest pulling force for fracture reduction.