A Survey to Assess Agreement Between Pelvic Surgeons on the Outcome of Examination Under Anesthesia for Lateral Compression Pelvic Fractures

Standardization and Reproducibility of Dynamic Stress Testing for Occult Pelvic Ring Instability

INTRODUCTION

Examination under anesthesia (EUA) (stress fluoroscopy) is commonly done after pelvic ring injury to identify occult instability because unstable disruptions may displace causing morbidity. The force applied during EUA for these injuries has not been standardized. The purpose of this study was to examine the forces used during the EUA by experienced orthopaedic trauma pelvic surgeons.

METHODS

Orthopaedic traumatologists performed simulated EUA on a cadaver at two North American pelvis and acetabular courses using internal rotation (IR), external rotation, and push-pull maneuvers while wearing a handheld dynamometer to measure force. All surgeons used a comparable method, and each performed EUA multiple times. Maximum forces were measured in Newton (N).

RESULTS

Eighteen surgeons participated. Four had been practicing for <5 years, six for 5 to 10 years, six for 11 to 20 years, and two for >20 years. Surgeons applied a force ranging from 40.4 to 374.9 N during IR, 72.9 to 338.4 N during external rotation, and 25 to 323 N during push-pull, with notable variability seen between surgeons. Three surgeons (18%) had >50-N variability on serial trials of a single EUA maneuver (IR).

DISCUSSION

This is the first study evaluating the forces applied during pelvic EUA used to assess ring stability. Notable variability existed among surgeons performing EUA and in serial examinations by the same surgeon. Additional study is needed to standardize the displacement measured and threshold for instability that guides management.

Patient Preferences for Operative Versus Nonoperative Treatment of LC1 Pelvis Fracture: A Discrete Choice Experiment

OBJECTIVES

To quantify how patients with lateral compression type 1 (LC1) pelvis fracture value attributes of operative versus nonoperative treatment.

METHODS

DESIGN

Discrete choice experiment.

SETTING

Three US Level 1 trauma centers.

PATIENT SELECTION CRITERIA

Adult survivors of an LC1 pelvis treated between June 2016 and March 2023 were identified from institutional registries. The choice experiment was administered as a survey from March through August 2023.

OUTCOME MEASURES AND COMPARISONS

Participants chose between 12 hypothetical comparisons of treatment attributes including operative or nonoperative care, risk of death, severity of pain, risk of secondary surgery, shorter hospital stay, discharge destination, and independence in ambulation within 1 month of injury. The marginal utility of each treatment attribute, for example, the strength of participants' aggregate preference for an attribute as indicated by their survey choices, was estimated by multinomial logit modeling with and without stratification by treatment received.

RESULTS

Four hundred forty-nine eligible patients were identified. The survey was distributed to 182 patients and collected from 72 patients (39%) at a median 2.3 years after injury. Respondents were 66% female with a median age of 59 years (IQR, 34-69 years). Before injury, 94% ambulated independently and 75% were working; 41% received operative treatment. Independence with ambulation provided the highest relative marginal utility (21%, P < 0.001), followed by discharge to home versus skilled nursing (20%, P < 0.001), moderate versus severe postdischarge pain (17%, P < 0.001), shorter hospital stay (16%, P < 0.001), secondary surgery (15%, P < 0.001), and mortality (10%, P = 0.02). Overall, no relative utility for operative versus nonoperative treatment was observed (2%, P = 0.54). However, respondents strongly preferred the treatment they received: operative patients valued operative treatment (utility, 0.37 vs. -0.37, P < 0.001); nonoperative patients valued nonoperative treatment (utility, 0.19 vs. -0.19, P < 0.001).

CONCLUSIONS

LC1 pelvis fracture patients valued independence with ambulation, shorter hospital stay, and avoiding secondary surgery and mortality in the month after their injury. Patients preferred the treatment they received rather than operative versus nonoperative care.

Pelvic binder radiography detects occult instability in cadaveric simulated lateral compression type I (LC1) pelvic fractures

OBJECTIVES

Occult instability in minimally displaced lateral compression (LC) pelvic ring injuries may have clinical relevance for treatment. We describe two novel LC pelvis fracture stress examinations - pelvic binder stress radiography (PBR) and pelvic binder stress bladder manometry (PBM) - which do not require sedation, anesthesia, patient transport, or radiation of personnel.

METHODS

A biomechanical study was performed with five fresh elderly cadavers. Sequential osteotomies of the pelvis simulated increasingly unstable LC pelvis fracture patterns (OTA/AO 61A2.2, 61B1.1a, 61B1.1b, 61B2.1). Compressive force was quantitatively applied using a pelvic binder and scale. Pelvis fracture displacement was measured on AP and inlet fluoroscopic views. Pelvic bladder pressure (PBM) was measured using a Foley catheter as a water column.

RESULTS

Fracture displacement strongly correlated with force applied (R2=0.600-0.963). PBR discriminated between simulated LC injuries. Mean displacement of 61B1.1b injuries >1cm was observed at 3.8kg on AP view and 5kg on inlet view. Mean displacement of 61B1.1a injuries >1cm was observed at 8.2kg on AP view and 9.3kg on inlet view. 61A2.2 injuries did not displace >1cm at forces up to 10kg. >95% of 61B1.1a and 61B1.1b injuries displaced >1cm at 10kg. PBM moderately correlated with force applied (R2=0.517-0.842) but did not discriminate between LC injuries.

CONCLUSIONS

PBR is feasible, precisely quantified occult mechanical instability in simulated LC pelvis fractures in response to reproducible applied force, and discriminated between simulated LC pelvis fractures. PBM did not discriminate between simulated LC fractures. A clinical trial to validate the safety and efficacy of PBR for assessing occult instability in LC pelvis fracture is warranted.

Postmobilization Plain Radiography After Lateral Compression Type 1 Pelvic Ring Injury Does Not Affect Treatment

INTRODUCTION

The purpose of this study was to describe the practice of postmobilization radiography after lateral compression type 1 pelvis ring injury. We hypothesized that postmobilization radiographs would be more frequent over time and would not influence treatment.

METHODS

Displacement of pelvis ring injury on initial and final plain radiographs was measured. Frequency of postmobilization radiography was determined, and the impact on treatment and final radiographical outcome were assessed.

RESULTS

Of the 156 patients reviewed, 98 (62.8%) were women and mean age was 60.1 years. Thirty-three of 156 patients (21.2%) had a postmobilization radiograph. Over 5 years, radiographs increased to 67% of presenting patients. None of the patients who received postmobilization plain radiographs (n = 33) had any change in clinical plan afterward; all continued with nonsurgical care. Initial fracture characteristics and alignment were no different for patients with postmobilization radiographs. Final alignment was unchanged in nearly 70%. Overall, 74% of all nonsurgical patients experienced no change in alignment, with similar rates among the patients with postmobilization radiographs.

DISCUSSION

Patients with an lateral compression type 1 fracture demonstrated no changes in care after receiving postmobilization radiographs. However, the frequency of postmobilization radiographs increased over time, denoting opportunities to reduce costs and to improve efficiency and safety.

Nonoperative management of minimally displaced lateral compression type 1 (LC1) injuries with comminuted rami fractures is associated with late displacement

PURPOSE

Rami comminution has been found to be predictive of lateral compression type 1 (LC1) injury instability on examination under anesthesia (EUA) and lateral stress radiographs (LSR). The purpose of this study was to evaluate how rami comminution and subsequent operative vs. nonoperative management impact the late displacement of these injuries.

METHODS

Retrospective review of a prospectively collected LC1 database was performed to identify all patients with minimally displaced LC1 injuries (< 1 cm) and follow-up radiographs over a four-year period (n = 125). Groups were separated based on the presence of rami comminution and subsequent management, including rami comminution/operative (n = 49), rami comminution/nonoperative (n = 54), and no comminution/nonoperative (control group, n = 22). The primary outcome was late fracture displacement, analyzed as both a continuous variable and as late displacement ≥ 5 mm.

RESULTS

As a continuous variable, late fracture displacement was lower in the comminuted rami/operative group as compared to the comminuted rami/nonoperative group (PD: -3.0 mm, CI: -4.8 to -1.6 mm, p = 0.0002) and statistically non-different from control. Late displacement ≥ 5 mm was significantly more prevalent in the comminuted rami/nonoperative group than in the comminuted rami/operative and no comminution/nonoperative groups (control)(PD: -33.9%, CI: -49.0% to -16.1%, p = 0.0002 and PD: -30.0%, CI: -48.2% to -6.5%, p = 0.02, respectively).

CONCLUSION

Late fracture displacement was greatest in the group with rami comminution/nonoperative management. Rami comminution, which has been previously associated with dynamic displacement on EUA and LSR, is also associated with a higher incidence of late displacement when managed nonoperatively.

LEVEL OF EVIDENCE

Level III, prognostic retrospective cohort study.

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

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

Pelvic ring injuries: recent advances in diagnosis and treatment

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

Combined Anterior-Posterior versus Posterior-Only Fixation of Stress-Positive Minimally Displaced Lateral Compression Type 1 (LC1) Pelvic Ring Injuries

OBJECTIVES

To compare hospital outcomes and late displacement between stress-positive minimally displaced lateral compression type 1 (LC1) pelvic ring injuries treated with combined anterior-posterior versus posterior-only fixation.

DESIGN

Retrospective comparative cohort.

SETTING

Urban level-one trauma center.

PATIENTS/PARTICIPANTS

LC1 injuries managed operatively.

INTERVENTION

Anterior-posterior versus posterior-only fixation.

MAIN OUTCOME MEASUREMENTS

Physical therapy (PT) clearance, discharge location, hospital length of stay (LOS), inpatient morphine equivalent doses (MED), and fracture displacement at follow-up.

RESULTS

Groups were similar in demographic and injury characteristics (age, high energy mechanism, ASA score, stress displacement, and rami/sacral fracture classifications). Anterior-posterior fixation resulted in longer operative times (median difference (MD): 27.0 minutes, 95% confidence interval (CI): 17.0 to 40.0, P < 0.0001) and had a trend of increased estimated blood loss (MD: 10 mL, CI: 0 to 30, P = 0.07). Patients with anterior-posterior fixation required less inpatient MEDs (MD: -180.0, CI: -341.2 to -15.0, P = 0.02), were more likely to clear PT by discharge (100% vs. 70%, proportional difference (PD): 30%, CI: 2.0%-57.2%, P = 0.02), were less likely to discharge to rehabilitation facilities (0% vs. 30%, PD: 30%, CI: 2.0%-57.2%, P = 0.02), and had a trend of less days to clear PT after surgery (MD: -1, CI: -2 to 0, P = 0.09) and decreased LOS (MD: -1, CI: -4 to 1, P = 0.17). Late fracture displacement did not differ between groups.

CONCLUSION

Anterior-posterior fixation of LC1 injuries was associated with an improved early hospital course-specifically, reduced inpatient opioid use and an increased number of patients who could clear PT and discharge home.

LEVEL OF EVIDENCE

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

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.

Emergency Department Stress Radiographs of Lateral Compression Type-1 Pelvic Ring Injuries Are Safe, Effective, and Reliable

BACKGROUND

Occult instability of lateral compression type-1 (LC1) pelvic ring injuries may be determined with a fluoroscopic stress examination under anesthesia (EUA) performed in the operating room. We hypothesized that LC1 injuries, similar to some fractures of the extremities, could be radiographically stressed for stability in the emergency department (ED). Our primary objective was to determine if stress examination of LC1 fractures could be safely and accurately performed in the ED and could be tolerated by patients.

METHODS

A prospective, consecutive series of 70 patients with minimally displaced LC1 pelvic injuries (<10-mm displacement on presentation) underwent stress examinations performed by the on-call orthopaedic resident in the ED radiology suite. The stress examination series included static 40° inlet, internal rotation stress inlet, and external rotation stress inlet views. Pelvic fractures that had positive stress results (≥10 mm of overlap of the rami) were indicated for a surgical procedure. These fractures also underwent EUA in order for the 2 techniques to be compared.

RESULTS

All patients tolerated the ED stress examination without general anesthetic or hemodynamic instability. Fifty-seven patients (81%) had negative stress results and were allowed to bear weight. All patients with negative stress results who had 3-month follow-up went on to radiographic union without substantial displacement. For the patients with a positive stress result in the ED, the mean displacement was 15.15 mm (95% confidence interval [CI], 10.8 to 19.4 mm) for the ED stress test and 15.60 mm (95% CI, 11.7 to 19.4 mm) for the EUA (p = 0.86). Two patients with a negative ED stress test did not mobilize during their hospitalization and underwent EUA and conversion to a surgical procedure. Thus, a total of 11 patients underwent both stress testing in the ED and EUA; no patient had a positive result on one test but a negative result on the other.

CONCLUSIONS

ED stress examination of LC1 injuries is a safe and reliable method to determine pelvic ring stability. The displacement measured in the ED stress examination is similar to the displacement measured under general anesthesia. Furthermore, a negative ED stress examination predicts successful nonoperative treatment. Given the results of this study, we encourage the use of stress examination in the ED for LC1-type injuries involving complete sacral fractures only. Widescale adoption of this streamlined protocol may substantially diminish cost, anesthetic risk, and potential operations for patients.

LEVEL OF EVIDENCE

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

A computed tomography based survey study investigating the agreement of the therapeutic strategy for fragility fractures of the pelvis

Treatment recommendations for fragility fractures of the pelvis (FFP) have been provided along with the good reliable FFP classification but they are not proven in large studies and recent reports challenge these recommendations. Thus, we aimed to determine the usefulness of the FFP classification determining the treatment strategy and favored procedures in six level 1 trauma centers. Sixty cases of FFP were evaluated by six experienced pelvic surgeons, six inexperienced surgeons in training, and one surgeon trained by the originator of the FFP classification during three repeating sessions using computed tomography scans with multiplanar reconstruction. The intra-rater reliability and inter-rater reliability for therapeutic decisions (non-operative treatment vs. operative treatment) were moderate, with Fleiss kappa coefficients of 0.54 (95% confidence interval [CI] 0.44–0.62) and 0.42 (95% CI 0.34–0.49). We found a therapeutic disagreement predominantly for FFP II related to a preferred operative therapy for FFP II. Operative treated cases were generally treated with an anterior–posterior fixation. Despite the consensus on an anterior–posterior fixation, the chosen procedures are highly variable and most plausible based on the surgeon’s preference.

The morphological mapping of lateral compression type 1 pelvic fracture and pelvic ring stability classification: a finite element analysis

Purpose

This finite element analysis assessed lateral compression (LC-1) fracture stability using machine learning for morphological mapping and classification of pelvic ring stability.

Methods

Computed tomography (CT) files of LC-1 pelvic fractures were collected. After morphological mapping and producing matrix data, we used K-means clustering in unsupervised machine learning to classify the fractures. Based on these subtypes, we manually added fracture lines in ANSYS software. Finally, we performed a finite element analysis of a normal pelvis and eight fracture subtypes based on von Mises stress and total deformation changes.

Results

A total of 218 consecutive cases were analyzed. According to the three main factors—zone of sacral injury and completion, pubic ramus injury side, and the sagittal rotation of the injured hemipelvis—the LC-1 injuries were classified into eight subtypes (I–VIII). No significant differences in stress or deformation were observed between unilateral and bilateral public ramus fractures. Subtypes VI and VIII showed the maximum stress while subtypes V–VIII showed the maximum deformation in the total pelvis and sacrum. The subtypes did not differ in superior public ramus deformation.

Conclusions

Complete fracture of sacrum zones 2/3 may be a feature of unstable LC-1 fractures. Surgeons should give surgical strategies for subtypes V–VIII.

Examination Under Anesthesia Improves Agreement on Mechanical Stability: A Survey of Experienced Pelvic Surgeons

OBJECTIVES

To assess agreement among experts in pelvic fracture management regarding stability and need for operative repair of lateral compression-type pelvic fractures with static radiographs compared to static radiographs and examination under anesthesia (EUA).

SETTING

Online survey.

PATIENTS/PARTICIPANTS

Ten patients who presented to our level-1 trauma center with a pelvic ring injury were selected. Vignettes were distributed to 11 experienced pelvic surgeons.

INTERVENTION

Examination under anesthesia.

MAIN OUTCOME MEASUREMENTS

Agreement regarding pelvic fracture stability and need for surgical fixation.

RESULTS

Agreement on stability was achieved in 4 (40%) cases without EUA compared to 8 (80%) cases with EUA. Interreviewer reliability was poor without EUA and moderate with EUA (0.207 vs. 0.592). Agreement on need to perform surgery was achieved in 5 (50%) cases compared to 6 (60%) cases with EUA. Interreviewer reliability was poor without EUA and moderate with EUA (0.250 vs. 0.432). For reference cases with agreement, surgeons were able to predict stability or instability using standard imaging in 57 of a possible 88 reviewer choices (64.8%) compared to 82 of 88 choices (93.2%) with the addition of EUA (P < 0.0001).

CONCLUSIONS

EUA increased agreement among experienced pelvic surgeons regarding the assessment of pelvic ring stability and the need for operative intervention. Further research is necessary to define specific indications for which patients may benefit from EUA.

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.

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.