Lateral compression fracture of the pelvis represents a heterogeneous group of complex 3D patterns of displacement

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Pelvic Ring Injuries: Stable or Not?

Pelvic ring injuries occur in varying severity and in vastly different patient demographics. Knowledge regarding which of these injuries require surgical intervention and which can be managed nonsurgically continues to evolve. Previous studies have shown validated criteria for sacral fractures and the posterior ring, explored the role of examination under anesthesia, and other forms of dynamic imaging. Although there is substantial information available, a comprehensive synthesis of this information is lacking. This article provides a comprehensive review of radiographic markers suggestive of stability, discusses treatment strategies, and proposes a treatment algorithm that is easily understood and applicable to not only those with a trauma background but also the general orthopaedic surgeon who will see these injuries frequently while on call.

Does Fracture Pattern Really Predict Displacement of LC1 Sacral Fractures?

BACKGROUND

Operative management of minimally displaced lateral compression type-1 (LC1) pelvic ring injuries remains controversial. We aimed to assess the proportion of LC1 pelvic fractures that displaced following nonoperative management as a function of specific ring fracture patterns, and we quantified the magnitude of this displacement.

METHODS

A retrospective review of the billing registry of a level-I trauma center was performed. Two hundred and seventy-three patients with a high-energy LC1 pelvic ring fracture and <5 mm of sacral displacement were included. The fracture pattern was characterized with use of computed tomography (CT) scans and radiographs. Absolute and interval pelvic ring displacement were quantified with use of previously described methodology.

RESULTS

Thirty-five pelvic ring injuries (13%) were displaced. The rate of displacement was 31% (15 of 49) for LC1 injuries involving a complete sacral fracture and bilateral ramus fractures, 12% (7 of 58) for injuries involving a complete sacral fracture and a unilateral ramus fracture, and 10% (5 of 52) for injuries involving an incomplete sacral fracture and bilateral ramus fractures. In displaced injuries, the average interval displacement was 4.2 mm (95% confidence interval [CI], 1.8 to 6.8) and the final displacement was 9.9 mm ± 4.2 mm.

CONCLUSIONS

Our study suggests that fracture characteristics can be used to predict the likelihood of displacement of LC1 fractures that are treated without surgery. To our knowledge, the present study is the first to describe the magnitude of displacement that may occur in association with LC1 pelvic ring injuries that are treated nonoperatively; however, further studies are needed to determine the clinical impact of this displacement.

LEVEL OF EVIDENCE

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

Post Post-Mobilization Films for LC1 Pelvic Ring Injuries: Follow up Stress Imaging Demonstrates Minimal Utility

OBJECTIVE

To assess the utility of outpatient postmobilization radiographs in the nonoperative treatment of lateral compression type I (LC1) (OTA/AO 61-B1) pelvic ring injuries.

DESIGN

Retrospective series.

SETTING

Academic, Level 1 trauma center, 2008-2018.

PATIENTS/PARTICIPANTS

A series of 173 patients with nonoperatively treated LC1 pelvic ring injuries was identified. Of these, 139 received a complete set of outpatient pelvic radiographs with which to assess displacement.

INTERVENTION

Outpatient pelvic radiographs to assess additional fracture displacement and potential need for surgical intervention.

MAIN OUTCOME MEASUREMENTS

Rate of conversion to late operative intervention based on radiographic displacement.

RESULTS

No patient in this cohort received late operative intervention. A majority of the patients sustained incomplete sacral fractures (82.6%) and unilateral rami fractures (75.1%), and 92.8% demonstrated less than 10 mm of displacement on their final radiographs.

CONCLUSIONS

There is a low utility of repeat outpatient radiographs of stable, nonoperative LC1 pelvic ring injuries as they do not undergo late displacement.

LEVEL OF EVIDENCE

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

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.

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.

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.

Rami Comminution Is Associated With Displacement of Minimally Displaced Lateral Compression Type 1 Injuries on Lateral Stress Radiographs

OBJECTIVES

To determine whether displacement on lateral stress radiographs (LSRs) in patients with minimally displaced lateral compression type 1 pelvic ring injuries is associated with any demographic and/or injury characteristics.

DESIGN

Retrospective comparative cohort.

SETTING

Urban level 1 trauma center.

PATIENTS/PARTICIPANTS

Ninety-three consecutive patients with minimally displaced lateral compression type 1 injuries.

INTERVENTION

Displacement of pelvic ring injury on LSR (≥10 mm vs. &lt;10 mm).

MAIN OUTCOME MEASUREMENTS

Demographic and injury characteristics (mechanism of injury, Nakatani rami classification, rami comminution, Denis zone, complete/incomplete sacral fracture, sacral comminution).

RESULTS

65.6% of patients (n = 61) had ≥10 mm of displacement on LSR. On univariate analysis, displacement was associated with increased age [median difference 11: confidence interval (CI), 2-23], female sex [proportional difference (PD): 25.1%, CI, 3.9%-44.4%], Nakatani classification (type I PD: 27.9%, type II PD: -19.5%), and rami comminution (PD: 55.6%, CI, 35.4%-71.3%). On multivariate analysis, displacement was only associated with rami comminution (odds ratio: 16.48, CI, 4.67-58.17). Displacement was not associated with energy of injury mechanism, sacral fracture Denis zone, complete sacral fracture, sacral comminution, or bilateral rami fractures.

CONCLUSIONS

Although rami comminution was the only variable found to be independently associated with displacement ≥10 mm on LSR, no single variable perfectly predicted displacement. Future studies are needed to determine whether displacement on stress radiographs should change the management of these injuries.

LEVEL OF EVIDENCE

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

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.

Nonoperative Treatment of Select Lateral Compression Type II Pelvic Ring Injuries (OTA/AO 61B2.2) Results in a Low Rate of Radiographic Displacement

OBJECTIVES

To quantify radiographic outcomes and to identify predictors of late displacement in the nonoperative treatment of lateral compression type II (LC-2) pelvic ring injuries.

DESIGN

Retrospective review.

SETTING

Two Level 1 trauma centers.

PATIENTS/PARTICIPANTS

Thirty eight patients 18 years of age or older with LC-2 pelvic ring injuries were included in the study.

INTERVENTION

Nonoperative treatment.

MAIN OUTCOME MEASUREMENTS

Crescent fracture displacement (CFD) was measured on initial axial computed tomography scan. Change in pelvic ring alignment was measured by the deformity index, simple ratio, and inlet and outlet ratios on successive plain radiographs.

RESULTS

Patients in this study had minimally displaced LC-2 pelvic ring injuries, with median initial CFD of 2 mm and median initial deformity index of 2%. No patients had a change of more than or equal to 10 percentage points in deformity index over the treatment period, but small amounts of displacement were seen on the other ratios. No patients initially selected for nonoperative treatment converted to operative treatment. No radiographic predictors of late displacement were identified. Bilateral pubic rami fractures and the presence of a complete sacral fracture ipsilateral to the crescent fracture were not associated with late displacement.

CONCLUSIONS

A spectrum of injury severity and stability exists in the LC-2 pattern. Nonoperative treatment of LC-2 injuries with low initial deformity and CFD results in minimal subsequent displacement.

LEVEL OF EVIDENCE

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

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.

Factors Associated With Failure of Superior Pubic Ramus Screws

OBJECTIVE

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

DESIGN

Retrospective.

SETTING

Single, Level 1 trauma center.

PATIENTS

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

INTERVENTION

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

MAIN OUTCOME MEASUREMENTS

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

RESULTS

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

CONCLUSIONS

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

LEVEL OF EVIDENCE

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

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.

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

OBJECTIVES

To assess agreement among pelvic surgeons regarding the interpretation of examination under anesthesia (EUA), the methodology by which EUA should be performed, and the definition of a positive examination.

DESIGN

Survey.

PATIENTS/PARTICIPANTS

Ten patients who presented to our Level 1 trauma center with a pelvic ring injury were selected as clinical vignettes. Vignettes were distributed to 15 experienced pelvic surgeons.

INTERVENTION

Examination under anesthesia.

MAIN OUTCOME MEASUREMENTS

Agreement regarding pelvic fracture stability (defined as >80% similar responses), need for surgical fixation, definition of an unstable EUA, and method of performing EUA.

RESULTS

There was agreement that a pelvic fracture was stable or unstable in 8 (80%) of 10 cases. There was agreement that fixation was required or not required in 6 (60.0%) of 10 cases. Seven (46.7%) surgeons endorsed performing a full 15-part EUA, whereas the other 8 (53.3%) used an abbreviated or alternative method. Eight (53.3%) surgeons provided a definition of what constitutes a positive EUA, whereas the remaining 7 did not endorse adhering to a strict definition.

CONCLUSIONS

Pelvic surgeons generally agree on what constitutes a positive or negative EUA but not necessarily the implications of a positive or negative examination. There is no clear consensus among surgeons regarding the method of performing EUA nor regarding the definition of a positive EUA.

LEVEL OF EVIDENCE

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

Feasibility of anterior pelvic ring fixation alone for treating lateral compression type 1 pelvic fractures with nondisplaced complete sacral fractures: a retrospective study

Purpose

The aim of this study was to evaluate the feasibility of anterior pelvic ring fixation alone for treating lateral compression type 1 (LC-1) fractures with nondisplaced complete sacral fractures.

Methods

Patients with LC-1 type pelvic fractures with nondisplaced complete sacral fractures in the Xi’an Honghui Hospital were screened. Those who underwent surgical treatment for the anterior pelvic ring fractures and conservative treatment for the sacral factures were included in the analysis. The Majeed and Short Form-12 (SF-12) functional scores were used to evaluate these patients.

Results

Of the 123 patients enrolled, 108 (88%) responded to our enquiries regarding the outcome. The mean follow-up period was 18.37 months for the 108 patients who responded. The mean SF-12 functional score was 48.22 ± 9.68. The mean Majeed score was 83.47 ± 9.23, including 52 with excellent, 47 with good, seven with fair, two with poor outcomes. The SF-12 functional and Majeed scores were significantly higher in those aged <45 years or without lower limb injury than in those aged ≥45 years or with lower limb injury (P < 0.05).

Conclusion

Acceptable functional outcomes can be obtained for LC-1 pelvic fractures with nondisplaced complete sacral fractures by using anterior pelvic ring fixation alone.

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.

Validated Radiographic Scoring System for Lateral Compression Type 1 Pelvis Fractures

OBJECTIVES

To develop a radiographic fracture scoring system for lateral compression type 1 (LC-1) pelvic fractures based on OTA/AO survey data and to preliminarily evaluate this system within an LC-1 pelvis fracture cohort.

DESIGN

Survey study with validation patient cohort.

SETTING

Two Level 1 academic trauma centers.

PATIENTS/PARTICIPANTS

Attendings (n=111) at the 2013 OTA/AO national meeting reviewed imaging from 27 LC-1 fractures and indicated surgical recommendations ("yes/no"). A separate LC-1 fracture cohort (33 patients) was used to evaluate the scoring system.

INTERVENTION

The LC-1 scoring system (range: 5-14) based on radiographic morphology of sacral, superior ramus (SR), and inferior ramus (IR) fracture components.

MAIN OUTCOME MEASUREMENT

Numeric scores were compared against (1) OTA/AO attendees' operative recommendations and (2) LC-1 cohort treatment and outcomes.

RESULTS

Operative tendency of OTA/AO survey respondents-defined as the percent of "yes" responses to recommend surgical stabilization-was highly correlated with radiographic findings: sacral displacement {odds ratio (OR) = 18.9 [95% confidence interval (CI): 11.7-30.6]}; sacral column 2-3 versus 1 [OR = 5.7 (95% CI: 3.9-8.3)]; Denis classification [OR = 10 (95% CI: 6.7-14.9); IR displacement OR = 3.4 (95% CI: 2.3-4.8)]; and SR fracture [OR = 1.9 (95% CI: 1.3-2.8)]. Total scores <7 were 81% accurate in predicting nonoperative treatment. Total scores >9 were 89% accurate in predicting an operative recommendation. In the LC-1 cohort, scoring accuracy was 100% (95% CI: 85%-100%).

CONCLUSIONS

Based on survey results and patient cohort data, scores <7 predict nonoperative treatment recommendation, scores >9 indicate surgical recommendations, and scores 7-9 indicate indeterminate stability that should be further evaluated.

Surgery for Unilateral Sacral Fractures: Are the Indications Clear?

OBJECTIVES

To evaluate unilateral sacral fractures and compare those treated operatively versus nonoperatively to determine indications for surgery.

DESIGN

Prospective, multicenter, observational study.

SETTING

Sixteen trauma centers.

PATIENTS/PARTICIPANTS

Skeletally mature patients with pelvic ring injury and unilateral zone 1 or 2 sacral fractures and without anteroposterior compression injuries.

MAIN OUTCOME MEASUREMENTS

Injury plain anteroposterior, inlet, and outlet radiographs and computed tomography scans of the pelvis were evaluated for fracture displacement.

RESULTS

Three hundred thirty-three patients with unilateral sacral fractures and a mean age of 41 years with a mean Injury Severity Score of 15 were included. Ninety-two percent sustained lateral compression injuries, and 63% of all fractures were in zone 1. Thirty-three percent of patients were treated operatively, including all without lateral compression patterns. Operative patients were more likely to have zone 2 fractures (54%) and to have posterior cortical displacement (29% vs. 6.2%), both with P < 0.001. Over 60% of all patients had no posterior displacement. Mean rotational displacements comparing the injured side versus the intact side were no different for patients treated operatively compared with those treated nonoperatively.

CONCLUSIONS

Most unilateral sacral fractures are minimally or nondisplaced. Many patients with radiographically similar fractures were treated operatively and nonoperatively by different surgeons. This suggests an opportunity to develop consistent indications for treatment.

LEVEL OF EVIDENCE

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

Decision-making, therapy, and outcome in lateral compression fractures of the pelvis - analysis of a single center treatment

Background

Pelvic lateral compression fractures are the most stable of the unstable fractures. Therefore, decision making regarding operative or non-operative therapy is still a matter of debate.

Methods

Factors, influencing decision making for therapy, were explored based on prospectively collected register data of a single Level-1 trauma center. The analysis included epidemiological records such as age and gender, and injury characterizing parameters such as degree of displacement and the Injury Severity Score (ISS). In-hospital mortality and complications served as short-term outcome variables. After matching for relevant confounders, long-term results were compared between operatively and non-operatively treated patients, evaluating the Merle d’Aubigne and the EQ. 5D-3 L scores.

Results

Over an 11-year period (2004–14), 134 patients suffered from lateral compression fractures out of 567 pelvic fractures (33%). After excluding patients with clear indications for operation (complex pelvic fractures and pubic symphysis ruptures) and pediatric fractures, 114 patients could be included in the analysis. Sixty-one patients were treated conservatively (54%), 53 with an operation (46%). The operated patients were younger (43.7 vs 58.3 years), had higher ISS (19.9 vs 15.5 points) and fracture displacements (2.3 vs 4.9 mm) (p < 0.001 for all). The length of hospital stay was shorter in the conservatively treated group (12.7 vs 17.3 days, p < 0.02). Although the types of complications were different, the incidence was not. The mortality was less in the operated group (1.9% vs. 6.6%), however, a logistic regression analysis showed that only the ISS was an independent risk factor, but not the type of therapy. Merle d’Aubigne and EQ. 5D-3 L scores were not different in the matched cohorts.

Conclusion

Decision-making for operative therapy was favored in severely injured young patients with high displacement. However, short- and long-term outcomes showed no difference between operatively and non-operatively treated patients.

Trial registration

DRKS, no. 00000488. Registered 14th July 2010 - Retrospectively registered

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

LEVEL OF EVIDENCE

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

Predictors of Unplanned Reoperation After Operative Treatment of Pelvic Ring Injuries

OBJECTIVES

To evaluate the incidence of unplanned reoperations after pelvic ring injuries and to develop a risk prediction model.

DESIGN

Retrospective review.

SETTING

Level I Trauma Center.

PATIENTS

The medical records of 913 patients (644 male and 269 female patients; mean age, 39 years; age range, 16-89 years) with unstable pelvic ring fractures operatively treated at our center from 2003 to 2015 were reviewed.

INTERVENTION

Multiple logistic regression analysis was conducted to evaluate the relative contribution of associated clinical parameters to unplanned reoperations. A risk prediction model was developed to assess the effects of multiple covariates.

MAIN OUTCOME MEASUREMENTS

Unplanned reoperation for infection, fixation failure, heterotopic ossification, or bleeding complication.

RESULTS

Unplanned reoperations totaled 137 fractures, with an overall rate of 15% (8% infection, 6% fixation failure, <1% heterotopic ossification, and <1% bleeding complication). Reoperations for infection and fixation failure typically occurred within the first month after the index procedure. Four independent predictors of reoperation were open fractures, combined pelvic ring and acetabular injuries, abdominal visceral injuries, and increasing pelvic fracture grade. No independent association was shown between reoperation and patient, treatment, or other injury factors.

CONCLUSIONS

Unplanned reoperations were relatively common. Infection and fixation failure were the most common indications for unplanned reoperations. Factors associated with reoperation are related to severity of pelvic and abdominal visceral injuries. Our findings suggest that these complications might be inherent and in many cases unavoidable despite appropriate current treatment strategies.

LEVEL OF EVIDENCE

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

Does Surgical Stabilization of Lateral Compression-type Pelvic Ring Fractures Decrease Patients' Pain, Reduce Narcotic Use, and Improve Mobilization?

BACKGROUND

Debate remains over the role of surgical treatment in minimally displaced lateral compression (Young-Burgess, LC, OTA 61-B1/B2) pelvic ring injuries. Lateral compression type 1 (LC1) injuries are defined by an impaction fracture at the sacrum; type 2 (LC2) are defined by a fracture that extends through the posterior iliac wing at the level of the sacroiliac joint. Some believe that operative stabilization of these fractures limits pain and eases mobilization, but to our knowledge there are few controlled studies on the topic.

QUESTIONS/PURPOSES

(1) Does operative stabilization of LC1 and LC2 pelvic fractures decrease patients' narcotic use and lower their visual analog scale pain scores? (2) Does stabilization allow patients to mobilize earlier with physical therapy?

METHODS

This retrospective study of LC1 and LC2 fractures evaluated patients treated definitively at one institution from 2007 to 2013. All patients treated surgically, all nonoperative LC2, and all nonoperative LC1 fractures with complete sacral injury were included. In general, LC1 or LC2 fractures with greater than 10 mm of displacement and/or sagittal/axial plane deformity on static radiographs were treated surgically. One hundred fifty-eight patients in the LC1 group (107 [of 697 screened] nonoperative, 51 surgical) and 123 patients in the LC2 group (78 nonoperative, 45 surgical) met inclusion criteria. The surgical and nonoperative groups were matched for fracture type. To account for differences between patients treated surgically and nonoperatively, we used propensity modeling techniques incorporating treatment predictors. Propensity scores demonstrated good overlap and were used as part of multiple variable regression models to account for selection bias between the surgically treated and nonoperative groups. Patient-reported pain scores and narcotic administration were tallied in 24-hour increments during the first 24 hours of hospitalization, at 48 hours after intervention, and in the 24 hours before discharge. Time from intervention to mobilization out of bed was recorded; intervention was defined as the date of definitive surgical intervention or the day the surgeon determined the patient would be treated without surgery.

RESULTS

There was no difference in the narcotics distributed to any of the groups with the exception that the patients with surgically treated LC2 fractures used, on average (mean [95% confidence interval]) 40.2 (-72.9 to -7.6) mg morphine less at the 48-hour mark (p = 0.016). In general, there were no differences between the groups' pain scores. The surgically treated patients with LC1 fractures mobilized 1.7 (-3.3 to -0.01) days earlier (p = 0.034) than their nonoperative counterparts. There was no difference in the LC2 cohort in terms of time to mobilization between those treated with and without surgery.

CONCLUSIONS

There were few differences in pain scores and morphine use between the surgical and nonoperative groups, and the differences observed likely were not clinically important. We found no evidence that surgical stabilization of certain LC1 and LC2 pelvic fractures improves patients' pain, decreases their narcotic use, and improves time to mobilization. A randomized trial of patients with similar fractures and similar degrees initial displacement would help remove some of the confounders present in this study.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Lateral compression type B 2-1 pelvic ring fractures in young patients do not require surgery

PURPOSE

According to Young and Burgess, type B 2-1 pelvic fractures are a type of lateral compression fracture (LC-1) and are the most common pelvic injury at all ages. Although they are considered unstable in rotation and despite biomechanical recommendations for anterior stabilization, most authors recommend non-operative treatment. However, studies comparing outcomes and complications regarding operative versus non-operative treatment are still scarce.

METHODS

Seventy-one patients aged under 65 years with a type B 2-1 pelvic fracture were treated between 2006 and 2011. Patients in Group I (n = 35) were treated non-operatively and patients in Group II (n = 36) were treated operatively. Postoperative complications, clinical course, and follow-up (VAS for Pain, SF 36, EQ-5D) of at least 1 year postoperatively were evaluated.

RESULTS

Our data show that operatively treated patients had a significantly higher complication rate. Preoperatively, the only significant difference between the non-operative and operative groups was the amount of anterior fracture dislocation and the presence of an isolated pelvic ring fracture. In the postoperative follow-up, no significant differences were found regarding pain or quality of life.

CONCLUSION

Type B 2-1 pelvic ring fractures in young patients should be treated non-operatively.

Computer-aided pelvic reduction frame for anatomical closed reduction of unstable pelvic fractures

Traditional closed reductions of unstable pelvic fractures are mainly performed by surgeons using manual manipulation and subjective verification based on intra-operative roentgenography. It is difficult to perform an accurate closed reduction because of a lack of adequate knowledge of the displacement patterns and an inability to apply the reduction in correct direction. Using the concept of the remote center of motion mechanism and computer-aided design software, we developed a pelvic reduction frame for use in anatomical closed reductions of unstable pelvic fractures. With three-dimensional reconstruction technique and the matrix algorithm, the spatial orientation of the displaced hemipelvis can be calculated and deconstructed into several rotational and translational movements that can be completed with the frame. To verify the accuracy of this system, the rotations were repeated 10 times in arbitrary degrees and directions. After the matrix is calculated, the displaced hemipelvis can be reduced to the anatomical position using our frame. The maximum residual translational and rotational displacements were less than 5 mm and 4 degrees, which indicated the accuracy of this system. The maximum average residual translation and rotation were 1.87 mm in Z-axis (ranging: 4.63-0.1 mm) and 1.1 degrees around Y-axis (ranging: 3.81-0.13 degrees), respectively. Only the Z-axial translation showed a statistically significant difference (p < 0.05). In conclusion, the proposed pelvic reduction frame could be a useful tool for the anatomical reduction of unstable pelvic fractures.

Radiographic diagnosis of sagittal plane rotational displacement in pelvic fractures: a cadaveric model and clinical case study

PURPOSES

Our objective was to measure the sagittal plane rotational (flexion and extension) displacement of hemipelvis radiologically and analyze the ratio of flexion and extension displacement of unstable pelvic fractures.

METHODS

We used 8 cadaveric models to study the radiographic evidence of pelvic fractures in the sagittal plane. We performed pelvic osteotomy on 8 cadavers to simulate anterior and posterior pelvic ring injury. Radiological data were measured in the flexion and extension group under different angles (5°, 10°, 15°, 20°, and 25°). We retrospectively reviewed 164 patients who were diagnosed with a unilateral fracture of the pelvis. Pelvic ring displacement was identified and recorded radiographically in cadaveric models.

RESULTS

The flexion and extension displacement of pelvic fractures was measured in terms of the vertical distance of fracture from the top of iliac crest to the pubic tubercle (CD) or from the top of iliac crest to the lowest point of ischial tuberosity (AB). Fifty-seven pelves showed flexion displacement and 15 showed extension displacement. Closed reduction including internal fixation and external fixation was successfully used in 141 cases (86.0 %). The success rates of closed reduction in flexion and extension displacement groups were 77 and 73 %, respectively, which were lower than in unstable pelvic ring fractures.

CONCLUSIONS

The sagittal plane rotation (flexion and extension) displacement of pelvic fractures could be measured by special points and lines on the radiographs. Minimally invasive reduction should be based on clearly identified differences between the sagittal plane rotation and the vertical displacement of pelvic fractures.

Operative agreement on lateral compression-1 pelvis fractures. a survey of 111 OTA members

OBJECTIVES

To better characterize operative agreement and disagreement among orthopaedic surgeons treating lateral compression type 1 (LC-1) pelvic fractures in an effort to improve communication between care providers and improve patient care.

DESIGN

Decision analysis.

SETTING

Level 1 trauma center.

METHODS

Twenty-seven LC-1 cases were selected to represent a wide array of LC-1 injuries. Each case was presented with 3 plain pelvic radiographs (anteroposterior, inlet, and outlet) and a scrollable computed tomography at the OTA national meeting. Attendees were queried whether they would perform operative stabilization "yes/no." Years of surgical practice (0-5, 6-10, and >10), annual pelvic fracture case volume (0-20, 21-50, and >50), and completion of a trauma fellowship (yes/no) were also collected. Fleiss' kappa (K) was used to measure operative agreement among survey respondents, where K = 0.21-0.40 was fair and K = 0.41-0.60 was moderate agreement.

RESULTS

One hundred eleven surgeons completed the survey where the average tendency to operate across surveys was 40%. Of the 27 cases presented, only 9 cases (33%) showed substantial agreement. There were 4 cases where nearly everyone chose operative stabilization (93.1%-94.4%) and 5 cases where nearly no one chose operative stabilization (0%-8.7%). The overall agreement was fair with K = 0.39 [95% confidence interval (CI), 0.34-0.44]. Although there was a trend for surgeons with more years of surgical practice to have a lower tendency to operate, it did not achieve statistical significance (odds ratio for >10 years vs. 0-5 years = 0.73; 95% CI, 0.48-1.11). Annual case volume and completion of a trauma fellowship were not statistically significant predictors of operative tendency.

CONCLUSIONS

Our results show only fair operative agreement (K = 0.39; 95% CI, 0.34-0.44) in a radiographic survey representing a broad range of LC-1 fracture morphologies among OTA surgeons. Only 9 of the 27 cases (33%) had substantial agreement. There was no difference in the decision to operate based on surgical volume, completion of a trauma fellowship, or time in practice. These results highlight the differing practice decisions among surgeons currently treating LC-1 injuries, and there is need for further studies to more fully understand stability after this injury pattern.

Nonoperative treatment of intermediate severity lateral compression type 1 pelvic ring injuries with minimally displaced complete sacral fracture

OBJECTIVES

Controversy exists regarding optimum management of lateral compression type 1 (LC1) pelvic ring injuries (OTA type 61-B2.1), particularly in patients with complete sacral fractures. We hypothesized that nonoperative treatment would result in acceptable functional outcomes.

DESIGN

Database review.

SETTING

Level I trauma center.

PATIENTS

We identified patients treated for LC1 fractures (n = 406) from 2007 to 2011 and analyzed a subset of LC1 injuries of "intermediate severity" characterized by complete sacral fracture with less than 1 cm initial displacement (n = 104).

INTERVENTION

Fifty patients were contacted for functional outcome assessment at average follow-up of 33 months.

MAIN OUTCOME MEASURES

Majeed pelvic score and physical component summary (PCS) score and mental component summary (MCS) score of 12-item Short-Form Health Survey version 2.

RESULTS

Average Majeed pelvic score was 85.5, yielding 33 excellent, 9 good, 5 fair, and 3 poor outcomes. Mean PCS and MCS scores were 48.8 and 48.9, respectively (both confidence intervals include 50, the score for a healthy normative population). Patients with lower extremity injuries had a trend toward lower PCS and MCS and statistically significant lower mean Majeed scores (P = 0.01). Thirty-five of 37 patients without lower extremity injury had good or excellent categorical outcomes based on Majeed scores. No significant differences were observed regarding weight-bearing status, extent of anterior ring injury, or injury severity score. Radiographic follow-up was available for 36 of 50 patients. No fracture was displaced >1 cm.

CONCLUSIONS

Acceptable functional outcomes can be expected after nonsurgical management of LC1 pelvic injuries with complete sacral fracture and less than 1 cm initial displacement.

LEVEL OF EVIDENCE

Therapeutic level IV.

Comparing the predictive value of the pelvic ring injury classification systems by Tile and by Young and Burgess

INTRODUCTION

Radiology-based classifications of pelvic ring injuries and their relevance for the prognosis of morbidity and mortality are disputed in the literature. The purpose of this study was to evaluate potential differences between the pelvic ring injury classification systems by Tile and by Young and Burgess with regard to their predictive value on mortality, transfusion/infusion requirement and concomitant injuries.

PATIENTS AND METHODS

Two-hundred-and-eighty-five consecutive patients with pelvic ring fractures were analyzed for mortality within 30 days after admission, number of blood units and total volume of fluid infused during the first 24h after trauma, the Abbreviated Injury Severity (AIS) scores for head, chest, spine, abdomen and extremities as a function of the Tile and the Young-Burgess classifications.

RESULTS

There was no significant relationship between occurrence of death and fracture pattern but a significant relationship between fracture pattern and need for blood units/total fluid volume for Tile (p<.001/p<.001) and Young-Burgess (p<.001/p<.001). In both classifications, open book fractures were associated with more fluid requirement and more severe injuries of the abdomen, spine and extremities (p<.05). When divided into the larger subgroups "partially stable" and "unstable", unstable fractures were associated with a higher mortality rate in the Young-Burgess system (p=.036). In both classifications, patients with unstable fractures required significantly more blood transfusions (p<.001) and total fluid infusion (p<.001) and higher AIS scores.

CONCLUSIONS

In this first direct comparison of both classifications, we found no clinical relevant differences with regard to their predictive value on mortality, transfusion/infusion requirement and concomitant injuries.

Evaluation of mesh morphing and mapping techniques in patient specific modeling of the human pelvis

Robust generation of pelvic finite element models is necessary to understand the variation in mechanical behaviour resulting from differences in gender, aging, disease and injury. The objective of this study was to apply and evaluate mesh morphing and mapping techniques to facilitate the creation and structural analysis of specimen-specific finite element (FE) models of the pelvis. A specimen-specific pelvic FE model (source mesh) was generated following a traditional user-intensive meshing scheme. The source mesh was morphed onto a computed tomography scan generated target surface of a second pelvis using a landmarked-based approach, in which exterior source nodes were shifted to target surface vertices, while constrained along a normal. A second copy of the morphed model was further refined through mesh mapping, in which surface nodes of the initial morphed model were selected in patches and remapped onto the surfaces of the target model. Computed tomography intensity based material properties were assigned to each model. The source, target, morphed and mapped models were analyzed under axial compression using linear static FE analysis and their strain distributions evaluated. Morphing and mapping techniques were effectively applied to generate good quality geometrically complex specimen-specific pelvic FE models. Mapping significantly improved strain concurrence with the target pelvis FE model.

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.

Nonoperative immediate weightbearing of minimally displaced lateral compression sacral fractures does not result in displacement

OBJECTIVES

The purpose of this study was to compare the initial and follow-up radiographs of patients with minimally displaced lateral compression (LC) sacral fractures treated nonoperatively with immediate weightbearing to determine the amount of displacement that occurs during healing.

DESIGN

Retrospective review.

SETTING

Single academic urban Level I Trauma Center.

PATIENTS/PARTICIPANTS

We evaluated 118 patients with a LC sacral fracture with <10 mm of displacement. There were 70 women and 48 men whose average age was 46 years and injury severity score was 15 ± 11.

INTERVENTION

Nonoperative treatment consisted of immediate foot-flat mobilization and advancement of weightbearing as tolerated. Repeat radiographs were routinely obtained once the patient had ambulated 50 feet or at 1 week to look for further displacement. Patients were followed with AP radiographs in the clinic at the 4- to 6-week and 10- to 12-week periods, and then every 6-8 weeks until they were healed.

MAIN OUTCOME MEASURES

Specific measurements were made on the initial and follow-up radiographs by 2 observers not involved in the treatment of the patients. A vertical plumb line drawn through the center of the S1 and S2 bodies served as an anchoring point for measurements. Key landmarks were measured on each side of the pelvis, which allowed for determination of the initial and final displacements.

RESULTS

All patients presenting to our center with LC sacral fractures with <10 mm of displacement were treated nonoperatively. One patient failed nonoperative management, demonstrating 5 mm of additional sacral displacement and having substantial pain with attempts to mobilize. This patient was treated with closed reduction and percutaneous pinning of the sacrum and an anterior external fixator. The other 117 patients (99%) healed with minimal additional displacement.

CONCLUSIONS

: Immediate weightbearing, tempered by patient comfort, is a safe and acceptable treatment for minimally displaced LC sacral fractures and results in union with minimal additional displacement.

Evaluation of mesh morphing and mapping techniques in patient specific modelling of the human pelvis

Robust generation of pelvic finite element models is necessary to understand variation in mechanical behaviour resulting from differences in gender, aging, disease and injury. The objective of this study was to apply and evaluate mesh morphing and mapping techniques to facilitate the creation and structural analysis of specimen-specific finite element (FE) models of the pelvis. A specimen-specific pelvic FE model (source mesh) was generated following a traditional user-intensive meshing scheme. The source mesh was morphed onto a computed tomography scan generated target surface of a second pelvis using a landmarked-based approach, in which exterior source nodes were shifted to target surface vertices, while constrained along a normal. A second copy of the morphed model was further refined through mesh mapping, in which surface nodes of the initial morphed model were selected in patches and remapped onto the surfaces of the target model. Computed tomography intensity-based material properties were assigned to each model. The source, target, morphed and mapped models were analyzed under axial compression using linear static FE analysis, and their strain distributions were evaluated. Morphing and mapping techniques were effectively applied to generate good quality and geometrically complex specimen-specific pelvic FE models. Mapping significantly improved strain concurrence with the target pelvis FE model.

Persistent impairment after surgically treated lateral compression pelvic injury

BACKGROUND

Recently, fixation of lateral compression (LC) pelvic fractures has been advocated to improve patient comfort and to allow earlier mobilization without loss of reduction, thus minimizing adverse systemic effects. However, the degree of acceptable deformity and persistence of disability are unclear.

QUESTIONS/PURPOSES

We determined if (1) injury pattern; (2) demographics; (3) final posterior displacement; (4) L5/S1 involvement; (5) associated injuries; and (6) time influence outcome measurements, sexual dysfunction, and pain.

METHODS

We retrospectively reviewed 119 patients with unstable LC injuries treated surgically between 2000 and 2010. There were 52 males and 67 females; mean age was 39 years with a mean body mass index of 27 kg/m(2). All patients underwent clinical examination and radiographic imaging for instability and accompanying injuries. We obtained Short Musculoskeletal Function Assessment (SMFA). The minimum followup was 12 months (mean, 33 months; range, 12-100 months).

RESULTS

SMFA subscores were not affected by injury pattern and demographics. Posterior reduction was less than 5 mm with persistent displacement in 99 of 119 (83%). Displacement of 5 to 10 mm did not affect any SMFA subscore at any time interval. Patients with additional lower extremity injuries had worse SMFA scores. Function improved with time. A visual analog scale pain score of 4 or more at 6 months predicted pain and overall SMFA score at last followup.

CONCLUSIONS

Unstable LC pelvic ring injuries result in persistent disability based on validated outcome measurements. Near anatomical reduction can be achieved and maintained. While our findings need to be confirmed in studies with high rates of followup, patients with unstable LC pelvic injuries should be counseled concerning the possibility of some degree of persistent disability.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

OTA highlight paper predicting future displacement of nonoperatively managed lateral compression sacral fractures: can it be done?

PURPOSE

This study was designed to assess the rate of displacement in nondisplaced sacral fractures and to determine if certain fracture patterns are more prone to future displacement.

DESIGN

Retrospective.

SETTING

Two Level I trauma centers.

PATIENTS

Patients consisted of those sustaining a lateral compression pelvic fracture whose age was 17 years or older, had less than 5 mm of initial sacral displacement, were the result of a high-energy mechanism, and had radiographs documenting bony union.

INTERVENTION

By protocol, patients meeting these criteria were mobilized and maintenance of alignment was documented by serial radiographs.

RESULTS

All fractures were classified according to the Orthopaedic Trauma Association classification system, the Young and Burgess mechanistic classification system, and to the location of the sacral fracture as described by Denis. In addition, sacral fractures were classified as complete or incomplete. Additionally, the number and location of rami fractures were recorded. Of the initial 117 fractures, 23 were determined to displace and largely consisted of a single fracture pattern. Fractures consisting of a complete sacral fracture combined with bilateral rami fractures displaced at a rate of 68% (15 of 22). In contrast, incomplete sacral fractures with an ipsilateral rami injury had no displaced unions.

CONCLUSION

Incomplete lateral compression sacral fractures that are associated with ipsilateral rami fractures can be treated nonoperatively and are unlikely to displace. In contrast, those with a complete sacral fracture and bilateral rami fractures displace at a significantly greater rate.

Biomechanical aspects of pelvic ring reconstruction techniques: Evidence today

Despite the remarkable advances achieved within the boundaries of the new discipline of Pelvic surgery, pelvic ring disruptions remain challenging and complex problems in orthopaedics. The long-term complications related to reconstruction techniques of these injuries have motivated researchers and surgeons to explore various alternative treatment modalities. Several biomechanical studies have addressed these issues. We performed a medline search including studies published during the last 30 years. Our search yielded 114 studies, 39 of which met the pre-specified inclusion criteria and were further critically analysed and discussed regarding the biomechanical aspects of pelvic ring reconstruction techniques. Based on observational approach and evaluation of the studies specific keypoints are highlighted comprising the clinical translation of the biomechanical supported findings.

Young and burgess type I lateral compression pelvis fractures: a comparison of anterior and posterior pelvic ring injuries

The goals of this study were to find associations between anterior and posterior ring injuries, provide a descriptive comparison of pelvic ring disruptions as assessed by plain radiography, and compare the value of computed tomography (CT) over plain radiography in evaluating anterior and posterior structures. A retrospective review of radiographic reports and records identified 142 patients with pubic ramus fractures as observed by plain radiography. A statistical analysis was performed to test the associations between anterior ring injury as assessed by plain radiography and posterior ring injury as assessed by CT. Forty-five point five percent of patients with bilateral ramus fractures and 42.0% of patients with dual-ramus fractures had concomitant sacral fractures not observed on plain radiographs. These occult sacral fractures were found in only 11.1% of patients with inferior ramus fractures. The type of pubic injury on plain radiographs may be predictive of posterior ring injury, and therefore may help determine injury energy and severity, determine the need for further imaging studies, and help guide clinical management. Although CT is highly sensitive in identifying both anterior and posterior pubic ring injuries, elderly patients with simple fractures of a single pubic ramus are less likely to suffer from pelvic instability and thus may not benefit from CT.

What constitutes a Young and Burgess lateral compression-I (OTA 61-B2) pelvic ring disruption? A description of computed tomography-based fracture anatomy and associated injuries

OBJECTIVE

The objectives of this study were to provide computed tomography (CT)-based description of the anatomic specifics of lateral compression (LC)-1 pelvic ring disruptions and to describe injury severity to other body systems and their correlation with fracture anatomy.

DESIGN

Retrospective radiographic assessment and review of records

SETTING

A level 1 trauma and tertiary referral center.

PATIENTS/PARTICIPANTS

We identified a consecutive series of 100 patients with Young and Burgess LC-1 pelvic ring disruptions from the trauma registry database at a level 1 trauma center and evaluated their radiographs, CT scans, and injury and admission information.

INTERVENTION

None.

MAIN OUTCOME MEASUREMENTS

Presentation films were used to confirm injury type. The CT scan of the bony pelvis was reviewed for each patient by independent reviewers, with disagreement being resolved by the senior author. Sixteen categories were reviewed for each patient (rami fractures, segmental/comminuted rami fractures, Nakatani classification of rami fractures, anterior and posterior sacral fractures, and Denis classification). Sacral fractures were graded based on severity (0, no fracture; 1, buckle fracture; 2, simple fracture line; 3, comminuted fracture line). The age, Injury Severity Score (ISS), and 6 categories of Abbreviated Injury Scale (AIS) were recorded for each patient. A statistical analysis was performed to test the associations between fracture characteristics and injury severity.

RESULTS

Our group had 54 women and 46 men. The mean age was 37.84 +/- 1.95. All patients but 3 had 1 or more rami fractures, and all but 2 had a sacral fracture. Of the 116 superior rami fractures, Nakatani 3 was the most common type (60/116, 51.7%). Of the 217 rami fractures, 47 (21.7%) were segmental or comminuted. Of the 98 anterior sacral injuries, there were 9 (9.2%) buckle fractures, 39 (39.8%) simple fractures, and 50 (51.0%) comminuted fractures. Of these 98 anterior sacral injuries, 47 (48.0%) were complete, passing through the sacrum and exiting the posterior cortex. Increasing severity of anterior sacrum fracture was associated with the presence of a complete sacral fracture (P < 0.0001). Of the 98 sacral fractures, 50 (50.0%) were Denis type 1, 41 (41.8%) Denis type II, and 7 (7.1%) Denis type III. Higher Denis types had higher likelihood of complete fractures of the sacrum (P < 0.0001). There was a significant association between the presence of a comminuted rami fracture and a complete sacrum injury (P = 0.003) and a trend to higher rates in Nakatani 2 superior rami fractures (P = 0.169). There were 4 deaths due to trauma in this group, and the mean ISS score was 17.16 +/- 1.3. The highest mean system AIS score in these patients was extremity (2.42 +/- 0.06) followed by chest (1.28 +/- 0.17) and abdomen (1.03 +/- 1.30). There was a trend to higher mean ISS scores (P = 0.2287) and significantly higher abdominal AIS scores (P = 0.0014) in those with a complete sacral fracture. Those with comminuted and complete sacral fractures were more likely to be symptomatic and require posterior ring stabilization (P = 0.003 and 0.043, respectively)

CONCLUSIONS

LC-1 fractures of the pelvic ring represent a spectrum of injuries, with a large proportion having complete disruption of the sacrum. This complete injury of the sacrum is predicted by Denis type, severity of anterior ring disruption, abdominal AIS, and potentially location of rami fracture and ISS. CT scanning best defines these injuries.