Anterior Pelvic Ring Fracture Pattern Predicts Subsequent Displacement in Lateral Compression Sacral Fractures

Lateral Compression Fragility Fractures of the Pelvis: Diagnosis, Classifications, and Modern Management

PURPOSE OF REVIEW

To describe the diagnosis, classification, and modern management of lateral compression fragility fractures of the pelvis.

RECENT FINDINGS

Practice patterns are shifting toward early operative treatment of fragility fractures of the pelvis among patients who are unable to mobilize or whose injuries demonstrate occult instability on stress imaging. Early internal fixation appears to decrease pain, facilitate mobilization, accelerate hospital discharge, and minimize morbidity in this population. Lateral compression pelvic ring injuries are the most common type of fragility fracture of the pelvis. Similar to fragility fractures of the hip, lateral compression fragility fractures of the pelvis are typically sustained in a ground level fall. These injuries are associated with long acute hospital and post-acute facility admissions, loss of physical function, loss of independence, mortality, anxiety, sleep disturbance, and caregiver burnout. Unlike hip fractures, for which urgent operative treatment and early mobilization reduce mortality, lateral compression fragility fractures of the pelvis are commonly treated without surgery. Recommendations for nonoperative management of these injuries in older adults may be inappropriately generalized from studies of younger patient populations with high-energy mechanisms of pelvis fracture. However, strong evidence to support early internal fixation of these injuries practice is lacking. High quality investigations of early surgical intervention for lateral compression fragility fractures of the pelvis are needed to guide care for these patients.

Stability before and after percutaneous anterior medullary fixation of lateral compression 1 and 2 pelvic ring disruptions: Should surgeons prioritize the anterior ring?

PURPOSE

Surgical intervention for lateral compression (LC) 1 and 2 pelvic ring fractures is controversial. Posterior ring stabilization remains the most common mode of initial fixation. However, greater mechanical instability is observed in the anterior component of LC pelvic fractures. This study tested whether reduction and percutaneous superior ramus fixation will decrease the instability of LC pelvic fractures on intraoperative fluoroscopic imaging.

METHODS

All adult patients (≥ 18 years) presenting with either a Young-Burgess LC1 or LC2 pelvic ring disruption treated operatively with percutaneous anterior followed by posterior fixation by a single surgeon from July 2021 to June 2023 were retrospectively reviewed. Displacement of the anterior ring to intraoperative manual internal rotation stress examination under fluoroscopy was compared before and after anterior pelvic ring reduction and fixation and prior to posterior pelvic ring fixation. Pre- and post-operative visual analog scores (VAS) for pain were also compared.

RESULTS

Twenty-one patients with a mean age of 48.7 years were included. Fifteen patients (71.4%) presented with an LC1, and six (28.6%) with an LC2 injury patterns. Anterior pelvic fixation alone provided 7.5mm reduction in mean displacement of the anterior pelvic ring (pre-operative = 9.2 mm vs. post-operative = 1.6 mm, p < 0.001). VAS significantly decreased from 7.2 one-day pre-operatively to 2.2 twenty-four h post-operatively (p < 0.001).

CONCLUSIONS

Reduction and fixation of the anterior pelvic ring prior to posterior fixation for LC1 and LC2 pelvic ring disruptions substantially improves mechanical stability on intraoperative stress examination. Combination of percutaneous anterior and posterior fixation significantly decreased VAS above the MCID 24 h after stabilization.

Variables Associated With Loss of Fixation of Retrograde Rami Screws in Minimally Displaced Lateral Compression Type 1 Pelvic Ring Injuries

OBJECTIVES

To evaluate variables associated with loss of fixation of retrograde rami screws in the treatment of stress-positive minimally displaced lateral compression type 1 (LC1) injuries.

METHODS

DESIGN

Retrospective comparative study.

SETTING

Level 1 trauma center.

PATIENT SELECTION CRITERIA

Stress-positive minimally displaced (<1 cm) LC1 pelvic ring injuries treated with retrograde rami screws.

OUTCOME MEASURES AND COMPARISONS

Loss of fixation, defined as >5 mm of pelvic fracture displacement based on the radiographic tear-drop distance or >5 mm of implant displacement on follow-up radiographs; revision surgery for loss of fixation.

RESULTS

Thirty-eight patients with 40 retrograde rami screws were analyzed. Median patient age was 64 years (interquartile range 42.5-73.3 years), 71.1% (n = 27/38) were female, and 52.6% (n = 20/38) of injuries were secondary to low-energy mechanisms. Loss of fixation occurred in 17.5% (n = 7/40) of screws with 10% (n = 4/40) requiring revision surgery. On univariate analysis, patients who had a loss of fixation were more likely to have greater dynamic displacement on stress radiographs (22.0 vs. 15.2 mm; median difference 5.6 mm, confidence interval [CI] -19.2 to 10.3; P = 0.04), unicortical rami screws (71.4% vs. 9.1%; proportional difference 62.3%, CI 8.8%-22.6%; P = 0.001), and partially threaded rami screws (71.4% vs. 21.2%; proportional difference 50.2%, CI 10.0%-77.6%; P = 0.01). The remaining variables had no observed association ( P ≥ 0.05) with loss of fixation, including age, sex, body mass index, energy of injury mechanism, tobacco use, American Society of Anesthesiologist score, sacral fracture type, distal rami fractures, rami comminution, number of sacral screws, fully threaded sacral screws, transsacral screws, or rami screw diameter. On multivariate analysis, only unicortical rami screws ( P = 0.01) remained associated with loss of fixation.

CONCLUSIONS

Retrograde rami screws had a high rate of loss of fixation in minimally displaced LC1 pelvic ring injuries, and this was associated with unicortical screws. These screws should be avoided when possible.

LEVEL OF EVIDENCE

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

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.

Comparison of Computer-Assisted Navigation and 3D Printed Patient-Specific Template for the Iliosacral Screw Placement

BACKGROUND

Iliosacral screw insertion by computer-assisted navigation gradually became the main technique in some hospitals, but the expensive price limited the extensive application. But other techniques such as 3D printed template was used to place iliosacral screw as novel method. This study was to compare the efficiency of percutaneous iliosacral screw placement by using patient-specific template and computer-assisted navigation.

METHODS

Total of 58 patients from September 2017 to September 2021 with sacral injury were treated operatively with percutaneous screw technique, which was selected for this retrospective analysis and divided into two groups (template and computer-assisted navigation). There were 31 patients in template group and 27 patients in computer-assisted navigation group. The surgical details (operation time, blood loss, number of screw placements, and number of fluoroscopies), complications, radiographic and clinical results were recorded. The quality of reduction was assessed by the Matta scoring system. T-test and rank-sum test was used in this study.

RESULTS

Operation time in template group was less (33.97 ± 16.61 < 60.31 ± 11.46 min, p < 0.01), but the preoperative preparation time was more (6.35 ± 1.60 > 5.41 ± 1.58, p < 0.05). The quality of reduction in both groups was no difference (p = 0.352). A patient was complicated with gluteal vessel injury in operation in navigation group, which was treated with ligation, but the same injury was not observed in template group. The related surgical data of patient with gluteal injury was ignored in statistical analysis.

CONCLUSION

Both of the two techniques could improve surgical efficiency, the operation time in template was less than computer-assisted navigation group, but the preoperative preparation time was more.

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.

Comparison of the two surgery methods combined with accelerated rehabilitation in the treatment of lateral compression type 1 pelvic fractures in the elderly

BACKGROUND

Treating lateral compression type 1 (LC1) pelvic ring injuries in older patients is controversial. This study evaluated surgical treatments combined with ERAS for treating LC1 pelvic fractures in the elderly.

METHODS

In this retrospective study, patients who underwent surgery with INFIX (supra-acetabular spinal pedicle screws, and a subcutaneous connecting rod; the experimental group) or superior pubic ramus cannulated screw (the control group) fixation of LC1 pelvic fracture from January 2019 to January 2022 were reviewed. Injury radiography and computed tomography were performed to determine the Young-Burgess classification. All patients performed standardized early rehabilitation exercises after surgery and were followed up for > 12 months. After surgery, the Matta score and the visual analog scale (VAS) were evaluated, and the postoperative weight-bearing time and the length of stay (LOS) were recorded. The Barthel index and the Majeed score were evaluated at 4 months after surgery and at the last follow-up.

RESULTS

Fifty-three patients were included. Thirty-two patients included in the experimental group had a mean age of 75.0 ± 6.2 (range, 66-86) years, and the other 21 patients in the control group had a mean age of 74.6 ± 4.6 (range, 68-83) years. The mean follow-up time was 13.1 ± 1.6 (range, 12-18) months in the experimental group and 13.4 ± 1.3 (range, 12-16) months in the control group. There were no significant differences in follow-up time between the groups (P > 0.05). The mean VAS score, time to weight-bearing, and LOS were 2.0 ± 0.7 (range, 1-3), 1.1 ± 0.3 (range, 1-2) d, and 5.8 ± 0.9 (range, 4-7) d in the experimental group and 2.3 ± 1.2 (range, 1-5), 2.5 ± 1.6 (range, 1-7) d, and 6.1 ± 1.6 (range, 5-11) d in the control group, respectively. Between the two groups, there was a significant difference in the postoperative time to weight-bearing (P < 0.05), while there was no significant difference in the LOS (P > 0.05). No bedrest-related complications occurred in either group. The Matta score was 90.6% in the experimental group and 90.4% in the control group (P > 0.05). At the 4-months follow-up, the experimental group had a better Barthel index and Majeed score compared with the control group, which were 86.1 ± 6.2 (range, 70-95) vs. 81.2 ± 4.1 (range, 75-90) and 86.3 ± 3.3 (range, 78-91) vs. 80.3 ± 3.9 (range, 76-86), respectively. The experimental group had better early rehabilitation effect than the control group. There was no significant difference in Barthel index and Majeed score between the two groups at the last follow-up (P > 0.05).

CONCLUSION

Both INFIX and intramedullary superior pubic ramus cannulated screws can successfully treat LC1 pelvic fractures and reduce bed rest complications among older patients.

Imaging of Pelvic and Acetabular Trauma: Part 1, Osseous Findings

Pelvic ring injuries and acetabular fractures are complex injuries and are often challenging to treat for a number of reasons. Orthopaedic trauma surgeons critically evaluate pelvic radiographs and CT images to generate an appropriate detailed injury and patient-specific preoperative plan. There are numerous crucial osseous details that surgeons should be aware of. Often, some of the most important factors that affect patients in treatment timing decisions, assessing reduction strategies, and deciding and inserting fixation constructs may be subtle on preoperative imaging. The radiographic and CT imaging findings covered subsequently should be sought out and appreciated preoperatively. Combining all the available osseous information helps the surgeon predict potential pitfalls and adjust surgical plans before incision. Ensuring a methodical and meticulous imaging review allows for the development of a detailed preoperative plan and helps avoid intraoperative missteps. This process will inherently streamline the surgical procedure and optimize the patient's surgical care. Maximizing the accuracy of the preoperative planning process can streamline the treatment algorithm and ultimately contribute to the best possible clinical outcome.

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.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Geriatric Patients Presenting With Isolated Pubic Rami Fractures and Inability to Mobilize May Have Occult Lateral Compression Pelvic Ring Injuries With Dynamic Instability

OBJECTIVES

To determine the incidence of patients with isolated pubic rami fractures on computed tomography scans who have dynamic instability secondary to occult lateral compression pelvic ring injuries.

DESIGN

Retrospective comparison study.

SETTING

Urban level 1 trauma center.

PATIENTS/PARTICIPANTS

This study included geriatric patients with isolated pubic rami fractures and inability to mobilize secondary to pain.

INTERVENTION

Lateral stress radiographs of pelvis to evaluate for ≥1 cm dynamic instability.

MAIN OUTCOME MEASUREMENTS

Physical therapy clearance, hospital length of stay, and discharge location.

RESULTS

A total of 19 patients were identified over 12 months. Patients were predominantly geriatric (median age: 75 years, interquartile range: 67 to 90), woman (11/19), with unilateral (17/19) comminuted distal rami fractures (12/19) sustained in ground-level falls (12/19). Dynamic instability was identified in 42% of patients (8/19). Magnetic resonance imaging, obtained in 6 of these patients, demonstrated occult posterior ring fractures in all cases. Patients with dynamic instability were more likely to have comminuted distal rami fractures (Nakatani type 1b) and a longer hospital length of stay. There was also a trend for these patients to be unable to clear physical therapy by discharge (63% (5/8) versus 36% (4/11)). The 90-day mortality rate of the cohort was 16% (3/19).

CONCLUSIONS

Patients presenting with seemingly isolated pubic rami fractures on radiographs and computed tomography scans who are unable to mobilize may have occult lateral compression injuries with dynamic instability.

LEVEL OF EVIDENCE

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

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.

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.

Finite Element Analysis of Channel Screw and Conventional Plate Technique in Tile B2 Pelvic Fracture

Objective: This study aims to analyze the biomechanical characteristics of tile B2 pelvic fractures using finite element analysis when the superior ramus of the pubis was fixed by a plate or hollow screws in standing and sitting positions, respectively. Methods: A three-dimensional digital model of the tile B2 pelvic fracture was obtained by CT scanning the patient. The main ligament structure was then reconstructed based on the anatomical characteristics to create a finite element model of the tile B2 pelvic fracture. The posterior pelvic ring was fixed by sacroiliac joint screws, while the anterior ring injury of the superior ramus of the pubis was fixed by plates and hollow compression screws, respectively. The degrees of freedom of the bilateral acetabulum or two sides of the ischial tuberosity were constrained in the two models. A vertical load of 600 N was applied to the upper surface of the sacrum to measure the displacement and stress distribution of the pelvis in the standing and sitting positions. Results: The displacement distribution of both the healthy and the affected side of the pelvis was relatively uniform in both the plate group and the hollow screw group according to the finite element simulation results. The maximum displacement value in the sitting position was greater than the standing position, and the maximum displacement value of the hollow screw fixation was greater than that of the plate fixation. In the four groups of fixation models, the maximum displacement value of the pelvis in the hollow screw sitting position group was 1616.80 × 10−3 mm, which was greater than that of the other three groups, and in this group the total displacement value of the hollow screw in the anterior ring was 556.31 × 10−3 mm. The stress distribution of the pelvis in the various models was similar in the four groups of models, in which the maximum stress of the pelvis in the hollow screw sitting position group was the largest, which was 201.33 MPa, while the maximum stress in the standing position was 149.85 MPa greater than that in the sitting position of the hollow screw fixation. Conclusion: The anterior ring of patients with Tile B2 pelvic fractures fixed with hollow screws or plates in both standing and sitting positions can achieve satisfactory biomechanical results with significant safety margins for plates and screws.