Fragility fractures of the sacrum: how to identify and when to treat surgically?

Morphometric analysis of sacral corridor in the upper three sacral segments to prevent neurovascular injury

Although studies of the sacral corridor dimension have been reported in the European population, little attention has been paid to this issue in the Asian population. The purpose of the study is to estimate the safe dimension of the corridor to avoid neurovascular damage during the fixation of the sacral fracture. The study aimed to examine the cephalocaudal (vertical) and the anteroposterior diameter of the bony passage in the upper three sacral segments. The study further examines the effect of age and sex on corridor dimensions at different sacral levels. Three-dimensionally reconstructed sacra from computed tomography of normal subjects were included in the study. Cephalocaudal and anteroposterior diameters were measured in coronal and axial sections using Geomagic Freeform Plus software. Anteroposterior diameter of the sacral corridor at the first, second, and third sacral segments are significantly higher in males (P=0.013, 0.0011, and <0.0001, respectively). The length of the sacrum also revealed sexual dimorphism (P<0.00016). The anteroposterior diameter of the second sacral segment (ap-S2c) correlated moderately with the first sacral anteroposterior diameter (ap-S1c) (R=0.519, P<0.001). The ap-S2c exhibited a moderate correlation to the third sacral segment (ap-S3c) (R=0.677, P<0.001). The sacral corridor at the level of S1 has the largest cephalocaudal (18.25 mm) and anteroposterior diameter (17.11 mm). Placement of the screw in the first sacral corridor may avoid damage to the neurovascular bundle during the fixation of the sacral fracture.

Sacral fracture associated with a Tarlov cyst causing an anterior sacral CSF fistula and intraventricular fat emboli - a case report and review of the literature

BACKGROUND

Sacral fractures are rare and either associated with high-energy trauma or osteoporosis in most cases. A search of the current literature on sacral fractures and cerebrospinal fluid fistula identified only few cases. Pathological fractures are uncommon and exceedingly rare in case of Tarlov cysts. Sacral fractures can be missed in oligosymptomatic patients. However, severe complications may emerge as shown by this case report.

METHODS

We present the case of a pathological sacral fracture at the level S2/3 following a low-impact trauma, associated with a Tarlov cyst, which was complicated by an anterior CSF fistula and intraventricular fat emboli.

RESULTS

The patient was treated conservatively with strict bedrest and a CT-guided blood patch. Postponed mobilization was successful with decreasing orthostatic symptoms. Follow-up MRI and CT imaging showed a complete resolution of the ventral CSF fistula and ossification of the fracture. The intraventricular fat did not resolve, however, there was no radiological sign of hydrocephalus with excellent clinical outcome at 6-months follow-up.

CONCLUSION

Although exceedingly rare, sacral Tarlov cysts may be associated with pathological fractures of the sacrum. Relevant complications can emerge and need to be properly addressed.

[Diagnostics and treatment of insufficiency fractures of the pelvis]

Insufficiency fractures of the pelvis have increased in recent years, primarily due to the demographic change and the incidence will continue to rise. In addition to conventional X‑rays, the diagnostics always require slice imaging. Unlike high-energy trauma magnetic resonance imaging (MRI) plays an important role in insufficiency fractures. Once the fracture has been diagnosed, in addition to the extent of instability in the anterior and posterior pelvic rings, the pain symptoms are crucial for the decision on surgical treatment. The basic principle is to stabilize as little as possible but as much as necessary. There are currently a variety of procedures that can be applied as a minimally invasive procedure, especially for the often slightly or displaced insufficiency fractures. The decisive factor for treatment is that it enables early mobilization of the patients. All of these measures must be accompanied by thorough diagnostics of osteoporosis and the appropriate treatment.

Bone cement reinforcement improves the therapeutic effects of screws in elderly patients with pelvic fragility factures

BACKGROUND

Pelvic fragility fractures in elderly individuals present significant challenges in orthopedic and geriatric medicine due to reduced bone density and increased frailty associated with aging.

METHODS

This study involved 150 elderly patients with pelvic fragility fractures. The patients were divided into two groups, the observation group (Observation) and the control group (Control), using a random number table. Artificial intelligence, specifically the Tianji Orthopedic Robot, was employed for surgical assistance. The observation group received bone cement reinforcement along with screw fixation using the robotic system, while the control group received conventional screw fixation alone. Follow-up data were collected for one-year post-treatment.

RESULTS

The observation group exhibited significantly lower clinical healing time of fractures and reduced bed rest time compared to the control group. Additionally, the observation group experienced less postoperative pain at 1 and 3 months, indicating the benefits of bone cement reinforcement. Moreover, patients in the observation group demonstrated significantly better functional recovery at 1-, 3-, and 6-months post-surgery compared to the control group.

CONCLUSION

The combination of bone cement reinforcement and robotic technology resulted in accelerated fracture healing, reduced bed rest time, and improved postoperative pain relief and functional recovery.

Standard imaging in the emergency department in geriatric patients with immobilizing pelvic pain after low-energy trauma or without trauma: X-ray vs. computed tomography

PURPOSE

Geriatric pelvic ring injuries, evaluated solely by X-ray, are often misclassified or even missed. This can result in prolonged immobilization and persistent pelvic pain. The aim of this study was to assess the sensitivity and specificity of X-ray imaging in patients aged ≥ 70 years with immobilizing pelvic pain.

METHODS

107 geriatric patients (23 males, 84 females) with immobilizing pain after traumatic or atraumatic causes were included in this retrospective study. 91 patients had an anteroposterior (AP) X-ray of the pelvis and after that a computed tomography (CT) of the pelvis. All patients were treated in a level 1 trauma center from December 2018 to September 2020. The mean age was 83.07 ± 6.08 years.

RESULTS

The overall evaluation of the diagnostic performance of AP Pelvic X-ray imaging in the study population compared to the CT pelvis ("gold standard") resulted in a sensitivity of (2.7 %) and a specificity of (94.4 %). Specific for pelvic ring fractures in the study population there was a sensitivity of (3.4 %) and a specificity of (94.4 %).

CONCLUSION

The results highlights issues with the AP Pelvic X-ray as the diagnostic tool of choice in this study population, confirming the findings of previous studies on the underestimated problem of osteoporotic pelvic ring fractures in geriatric patients. This again confirms the need for a new optimized diagnostic algorithm, which takes into account the differences of the orthogeriatric patient cohort.

Sacroiliac versus transiliac-transsacral screw osteosynthesis in osteoporotic pelvic fractures: a biomechanical comparison

INTRODUCTION

Pelvic fractures were often associated with high-energy trauma in young patients, but data show a significant increase in osteoporotic pelvic fractures in old age due to the progressive demographic change. There is an ongoing discussion about the best fixation techniques, which are ranging from lumbopelvic fixation to sacral bars or long transiliac-transsacral (TITS) screws. This study analyzes TITS screw osteosynthesis and sacroiliac screw osteosynthesis (SI), according to biomechanical criteria of fracture stability in osteoporotic human pelvic cadavers ex vivo.

METHODS

Ten osteoporotic cadaveric pelvises were randomized into two groups of 5 pelvises each. An FFP-IIc fracture was initially placed unilaterally and subsequently surgically treated with a navigated SI screw or a TITS screw. The fractured side was loaded in a one-leg stance test setup until failure. Interfragmentary movements were assessed by means of optical motion tracking.

RESULTS

No significant difference in axial stiffness were found between the SI and the TITS screws (21.2 ± 4.9 N and 18.4 ± 4.1 N, p = 0.662). However, there was a significantly higher stability of the fracture treatment in the cohort with TITS-screws for gap angle, flexion, vertical movement and overall stability. The most significant difference in the cycle interval was between 6.000 and 10.000 for the gap angle (1.62 ± 0.25° versus 4.60 ± 0.65°, p = 0.0001), for flexion (4.15 ± 0.39 mm versus 7.60 ± 0.81 mm, p = 0.0016), interval 11.000-15.000 for vertical shear movement (7.34 ± 0.51 mm versus 13.99 ± 0.97 mm, p < 0.0001) and total displacement (8.28 ± 0.66 mm versus 15.53 ± 1.07 mm, p < 0.0001) for the TITS and the SI screws.

CONCLUSIONS

The results of this biomechanical study suggest a clear trend towards greater fracture stability of the TITS screw with significantly reduced interfragmentary movement. The application of a TITS screw for the treatment of the osteoporotic pelvic ring fracture may be prioritized to ensure the best possible patient care.

Assessment of the Initial Diagnostic Accuracy of a Fragility Fracture of the Sacrum: A Study of 56 Patients

STUDY DESIGN

Retrospective study.

PURPOSE

To investigate the clinical manifestations of a fragility fracture of the sacrum (FFS) and the factors that may contribute to a misdiagnosis.

OVERVIEW OF LITERATURE

The number of patients diagnosed with FFS has increased because of extended life expectancy and osteoporosis. Patients with FFS may report nonspecific symptoms, such as back, buttock, groin, and/or leg pain, leading to a misdiagnosis and a delay in definitive diagnosis.

METHODS

Fifty-six patients (13 males and 43 females) with an average age of 80.2±9.2 years admitted to the hospital for FFS between 2006 and 2021 were analyzed retrospectively. The following patient data were collected using medical records: pain regions, a history of trauma, initial diagnoses, and rates of fracture detection using radiography, computed tomography (CT), and magnetic resonance imaging (MRI).

RESULTS

Forty-one patients presented with low back and/or buttock pain, nine presented with groin pain, and 17 presented with thigh or leg pain. There was no history of trauma in 18 patients (32%). At the initial visit, 27 patients (48%) were diagnosed with sacral or pelvic fragility fractures. In contrast, 29 patients (52%) were initially misdiagnosed with lumbar spine disease (23 patients), hip joint diseases (three patients), and buttock bruises (three patients). Fracture detection rates for FFS were 2% using radiography, 71% using CT, and 93% using MRI. FFS was diagnosed definitively using an MRI with a coronal short tau inversion recovery (STIR) sequence.

CONCLUSIONS

Some patients with FFS have leg pain with no history of trauma and are initially misdiagnosed as having lumbar spine disease, hip joint disease, or simple bruises. When these clinical symptoms are reported, we recommend considering FFS as one of the differential diagnoses and performing lumbar or pelvic MRIs, particularly coronal STIR images, to rule out FFS.

Current consensus and clinical approach to fragility fractures of the pelvis: an international survey of expert opinion

Introduction

Fragility fractures of the pelvis (FFP) in elderly patients are an underappreciated injury with a significant impact on mobility, independency, and mortality of affected patients and is a growing burden for society/health care. Given the lack of clinical practice guidelines for these injuries, the authors postulate there is heterogeneity in the current use of diagnostic modalities, treatment strategies (both operative and nonoperative), and follow-up of patients with FFP. The goal of this study was to assess international variation in the management of FFP.

Methods

All International Orthopaedic Trauma Association (IOTA) steering committee members were asked to select 15 to 20 experts in the field of pelvic surgery to complete a case-driven international survey. The survey addresses the definition of FFP, use of diagnostic modalities, timing of imaging, mobilization protocols, and indications for surgical management.

Results

In total, 143 experts within 16 IOTA societies responded to the survey. Among the experts, 86% have >10 years of experience and 80% works in a referral center for pelvic fractures. However, only 44% of experts reported having an institutional protocol for the management of FFP. More than 89% of experts feel the need for a (inter)national evidence-based guideline. Of all experts, 73% use both radiographs and computed tomography (CT) to diagnose FFP, of which 63% routinely use CT and 35% used CT imaging selectively. Treatment strategies of anterior ring fractures were compared with combined (anterior and posterior ring) fractures. Thirty-seven percent of patients with anterior ring fractures get admitted to the hospital compared with 75% of patients with combined fractures. Experts allow pain-guided mobilization in 72% after anterior ring fracture but propose restricted weight-bearing in case of a combined fracture in 44% of patients. Surgical indications are primarily based on the inability to mobilize during hospital admission (33%) or persistent pain after 2 weeks (25%). Over 92% plan outpatient follow-up independent of the type of fracture or treatment.

Conclusion

This study shows that there is a great worldwide heterogeneity in the current use of diagnostic modalities and both nonoperative and surgical management of FFP, emphasizing the need for a consensus meeting or guideline.

[Sacral H-shaped fractures between traumatic, insufficiency and fatigue fractures : Similarities, differences and controversies]

In the basic entirety of stress fractures, insufficiency fractures are defined as fractures caused by prolonged normal or physiological loading of a bone with insufficient elastic resistance. This clearly distinguishes it from fatigue fractures, in which excessive loads are continuously applied to a bone with normal elastic resistance. According to Pentecost (1964) both entities of stress fracture result from "the inherent inability of the bone to withstand stress applied without violence in a rhythmical, repeated, subthreshold manner". This distinguishes them from acute traumatic fractures. In the clinical routine these differences are not always so clearly presented. The example of the H‑shaped sacral fracture is used to illustrate the relevance of a clear terminology. In this context, current controversies in the treatment of sacral insufficiency fractures are discussed.

Pelvic Ring Fractures in Older Adult Patients-Assessing Physician Practice Variation among (Orthopedic) Trauma Surgeons

PURPOSE

Pelvic fractures in older adults are a major public health problem and socioeconomic burden. The standard of care has changed over the past years, and there is limited consensus on which patients benefit from surgical fixation. There is currently no nationwide treatment protocol to guide the decision-making process. Therefore, the aim of this survey was to provide more insight into if, when, and why patients with a fragility fracture of the pelvis (FFPs) would be considered for additional imaging and surgical fixation by treating physicians.

METHODS

An online clinical vignette-based survey of hypothetical scenarios was sent out to all orthopedic and trauma surgeons in the Netherlands. The questionnaire comprised multiple-choice questions and radiographic images. Differences between subgroups were calculated using the X2 test or the Fisher exact test.

RESULTS

169 surgeons responded to the survey, with varying levels of experience and working in different types of hospitals. In a patient with a simple pubic ramus fracture and ASA 2 or ASA 4, 32% and 18% of the respondents would always advise a CT scan for further analysis. In the same patients, 11% and 31% of the respondents would not advise a CT scan, respectively. When presented with three cases of increasing severity of co-morbidity (ASA) and/or increasing age and/or different clinical presentation of an FFP type 3c on a CT scan, an increasing number of respondents would not consider surgical fixation. There was significant variation in practice patterns between the respondents who do not work in a hospital performing pelvic and acetabular (P&A) fracture surgery and those who do work in a P&A referral hospital. Most respondents (77%) refer patients 1-5 times a year to an expert center for surgical fixation.

CONCLUSION

There is currently a wide variety of clinical practices regarding the imaging and management of FFPs, which seems to be influenced by the type of hospital the patients are presented to. A regional or national evidence-based treatment protocol should be implemented to ensure a more uniform approach.

Conservative versus operative treatment of FFP II fractures in a geriatric cohort: a prospective randomized pilot trial

A clear recommendation regarding treatment strategy of fragility fractures of the pelvic ring is missing. The most typical fracture pattern is a lateral compression type injury with non-displaced fractures of the anterior pubic rami and a unilateral os sacrum fracture (FFP II). We hypothesized that operative treatment would be superior to conservative treatment. From October 2017 to April 2020, a randomized prospective non-blinded trial with n = 39 patients was carried out. Two arms with 17 operative versus 22 conservative cases were created. Inclusion criteria were a posterior pelvic ring fracture FFP type II, age over 60 years and acute fracture (< 3 weeks). Barthel index, pain level (VAS), quality of life (EQ-5D-3L), and Tinetti-Gait Test were determined on admission, at discharge, and after 3, 6, 12 and 24 months. Median follow-up was 12.9 months. The Barthel index (= 0.325), VAS (p = 0.711), quality of life (p = 0.824), and Tinetti-Gait Test (p = 0.913) showed no significant differences between the two groups after 12 months. Two patients switched from the conservative to the operative arm due to persistent immobilization and pain. The one-year mortality rate showed no significant difference (p = 0.175). Our hypothesis that surgical treatment is superior was refuted. No significant benefit was shown in terms of quality of life, mortality and pain levels. The results suggest a more differentiated treatment approach in the future, with initial conservative treatment preferred. A larger multi-center trial is required to confirm these findings.Trial registration: The study was retrospectively registered with the German Clinical Trials Registry (DRKS00013703) on 10/12/2018.

Imaging of pelvic ring fractures in older adults and its clinical implications-a systematic review

Identifying the full scope of pelvic fracture patterns in older adults has gained clinical importance since the last decennium. CT is recommended as the golden standard; however, MRI has even greater diagnostic accuracy. Dual energy computed tomography (DECT) is a new and promising imaging technique, but the diagnostic accuracy in the context of pelvic fragility fractures (FFPs) has not been widely established. The aim was to provide insight into the diagnostic accuracy of different imaging techniques and the relevance for clinical practice. A systematic search was performed in the PubMed database. All studies that reported on CT, MRI or DECT imaging techniques in older adults who suffered a pelvic fracture were reviewed and, if relevant, included. Eight articles were included. In up to 54% of the patients, additional fractures were found on MRI compared to CT, and in up to 57% of the patients on DECT. The sensitivity of DECT for posterior pelvic fracture detection was similar to MRI. All patients without fractures on CT appeared to have posterior fractures on MRI. After additional MRI, 40% of the patients had a change of classification. DECT and MRI showed very similar results in terms of diagnostic accuracy. Over a third of all patients appear to have a more severe fracture classification after MRI, the majority changing to Rommens type 4. However, in only a few patients who changed of fracture classification, a change of therapy was advised. This review suggests that MRI and DECT scans are superior in diagnosing FFPs.

Clinical Guidelines for the Diagnosis and Treatment of Fragility Fractures of the Pelvis

BACKGROUND

Fragility fractures of the pelvis (FFPs) are osteoporotic pelvic fractures or insufficiency pelvic fractures caused by the low energy injury or stress fracture in daily livings in the elderly more than 60 years, which the incidence is increasing with the aging population in our country. FFPs result in considerable morbidity and mortality and as well as massive financial burden on the already strained health systems throughout the world.

METHODS

This clinical guideline was initiated by the Trauma Orthopedic Branch of Chinese Orthopedic Association; the External Fixation and Limb Reconstruction Branch of Chinese Orthopedic Association; the National Clinical Research Center for Orthopedics, Sports Medicine & Rehabilitation; Senior Department of Orthopedics of Chinese PLA general hospital; the Third Hospital of Hebei Medical University. The grading of recommendations assessment, development and evaluation (GRADE) approach and the reporting items for practice guidelines in healthcare (RIGHT) checklist were adopted.

RESULTS

22 evidence based recommendations were formulated based on 22 most concerned clinical problems among orthopedic surgeons in China.

CONCLUSION

Understanding these trends through this guideline will facilitate better clinical care of FFP patients by medical providers and better allocation of resources by policy makers.

Retrospective evaluation of percutaneous 3D-navigated screw fixation for fragility fractures of the sacrum: technical notes and four-year experience

The incidence of fragility fractures of the sacrum is increasing due to demographic changes. In this study, we introduce the 3D-navigated monoportal percutaneous sacroiliac screw fixation (PSS) as a technical advancement for treating fragility fractures of the sacrum. We included all patients who underwent the 3D-navigated monoportal PSS for fragility fractures of the sacrum. The fractures were classified using the Fragility Fractures of the Pelvis score (FFP). We provide a step-by-step illustration of the surgical technique. The objective of this study was to assess the feasibility and safety of the investigated technique. Forty-six patients (36 female, 10 male) with a median age of 81.5 years were included in the study. The fracture classification revealed 23 FFP2 (50%), 5 FFP3 (11%), and 18 FFP4 (39%) fractures. In 35 cases (76%), only transsacral screws were implanted in S1 and S2, with an average incision-to-suture time of 52.6 min. The remaining eleven patients underwent additional anterior pelvic ring fixation, lumbar instrumentation, or kyphoplasty. There were no instances of nerve root, vascular, or pelvic organ injuries. The median postoperative in-hospital stay was six days. Out of the 36 patients who were followed up, four patients required revision surgery due to screw loosening. No significant risk factor for screw loosening was identified in the multiple regression analysis. The presented monoportal PSS technique for fragility fractures of the sacrum is a promising minimally invasive approach with a low complication rate and excellent short-term outcomes.

Validation of the Hierarchical Nature of the AO Spine Sacral Classification and the Development of the Sacral AO Spine Injury Score

STUDY DESIGN

Global cross-sectional survey.

OBJECTIVE

The objective of this study was to validate the hierarchical nature of the AO Spine Sacral Classification System and develop an injury scoring system.

SUMMARY OF BACKGROUND DATA

Although substantial interobserver and intraobserver reliability of the AO Spine Sacral Classification System has been established, the hierarchical nature of the classification has yet to be validated.

METHODS

Respondents numerically graded each variable within the classification system for severity. Based on the results, a Sacral AO Spine Injury Score (AOSIS) was developed.

RESULTS

A total of 142 responses were received. The classification exhibited a hierarchical Injury Severity Score (ISS) progression (A1: 8 to C3: 95) with few exceptions. Subtypes B1 and B2 fractures showed no significant difference in ISS (B1 43.9 vs. B2 43.4, P =0.362). In addition, the transitions A3→B1 and B3→C0 represent significant decreases in ISS (A3 66.3 vs. B1 43.9, P <0.001; B3 64.2 vs. C0 46.4, P <0.001). Accordingly, A1 injury was assigned a score of 0. A2 and A3 received scores of 1 and 3 points, respectively. Posterior pelvic injuries B1 and B2 both received a score of 2. B3 received a score of 3 points. C0, C1, C2, and C3 received scores of 2, 3, 5, and 6 points, respectively. The scores assigned to neurological modifiers N0, N1, N2, N3, and NX were 0, 1, 2, 4, and 3, respectively. Case-specific modifiers M1, M2, M3, and M4 received scores of 0, 0, 1, and 2 points, respectively.

CONCLUSIONS

The results of this study validate the hierarchical nature of the AO Spine Sacral Classification System. The Sacral AOSIS sets the foundation for further studies to develop a universally accepted treatment algorithm for the treatment of complex sacral injuries.

LEVEL OF EVIDENCE

Level IV-Diagnostic.

Surgical treatment of sacral nonunions

Sacral fractures are complex injuries that follow a bimodal distribution, typically involving acute high energy trauma in young adults and low energy trauma in older adults (> 65 years old). Nonunion is a rare but debilitating potential complication of undiagnosed or improperly managed sacral fractures. Various surgical techniques, including open reduction and internal fixation, sacroplasty, and percutaneous screw fixation, have been used to manage these fracture nonunions. In addition to reviewing the initial management of sacral fractures and the risk factors for fracture nonunion, this article describes techniques, specific cases and outcomes of these treatment strategies.

Posterior pelvic ring involvement detected with CT taken within a week of admission in acute fragility fractures of the pelvis (FFP) does not predict failure of conservative treatment: a retrospective cohort study

BACKGROUND

Acute low energy pubic rami fractures in the elderly receive primarily conservative treatment. There is debate to what extent posterior ring involvement, which is detected superiorly by CT compared to X-ray, has an impact on outcome and may require modified treatment. We want to demonstrate if posterior ring involvement has an influence on different types of outcome in primarily conservatively treated acute FFP, questioning the usefulness of early CT. Additionally we analysed the early fracture pattern in cases where conservative treatment failed with need for secondary surgery.

METHODS

A retrospective cohort study of 155 consecutive patients, recruited between 2009 and 2016, aged over 65 years diagnosed with an acute LE-PFr on X-ray at the emergency department of a single, level-one trauma centre and receiving an early CT. A set of outcome parameters was compared between patients with an isolated pubic rami fracture (CTia) and patients who had a combined posterior pelvic ring fracture (CTcp).

RESULTS

There were 155 patients of whom 85.2% were female with a mean age of 83 years. 76.8% of patients living at home returned home and 15.5% moved to a nursing home. Mortality rate during hospitalisation was 6.4% and 14.8% at one year post-trauma. Secondary fracture displacement occurred in 22.6%. Secondary surgery was performed in 6 cases (3.9%). Median hospitalisation length of stay was 21 days (range 0 to 112 days). There was no significant association between the subgroups and change in residential status (p = 0.65), complications during hospitalisation (p = 0.75), mortality rate during admission (p = 0.75) and at 1 year (p = 0.88), readmission within 30 days (p = 0.46) and need for secondary surgery (p = 0.2). There was a significant increased median length of stay (p = 0.011) and rate of secondary displacement (p = 0.015) in subgroup CTcp. Secondary displacement had no impact on in-hospital complications (p = 0.7) nor mortality rate during admission (p = 0.79) or at 1 year (0.77). Early CT in patients who underwent secondary surgery showed stable B2.1 lesions in 4 of 6 cases.

CONCLUSIONS

Our data suggest that early CT in patients with conservatively treated acute LE-PFr in order to detect posterior lesions, has limited value in predicting failure of conservative treatment.

Management of C0 Sacral Fractures Based on the AO Spine Sacral Injury Classification: A Narrative Review

The Arbeitsgemeinschaft fur Osteosynthese fragen Spine Sacral Injury Classification hierarchically separates fractures based on their injury severity with A-type fractures representing less severe injuries and C-type fractures representing the most severe fracture types. C0 fractures represent moderately severe injuries and have historically been referred to as nondisplaced "U-type" fractures. Injury management of these fractures can be controversial. Therefore, the purpose of this narrative review is to first discuss the Arbeitsgemeinschaft fur Osteosynthese fragen Spine Sacral Injury Classification System and describe the different fracture types and classification modifiers, with particular emphasis on C0 fracture types. The narrative review will then focus on the epidemiology and etiology of C0 fractures with subsequent discussion focused on the clinical presentation for patients with these injuries. Next, we will describe the imaging findings associated with these injuries and discuss the injury management of these injuries with particular emphasis on operative management. Finally, we will outline the outcomes and complications that can be expected during the treatment of these injuries.

Causes of Increased Use of Closed Reduction and Internal Fixation for High-Energy-Related Traumatic Sacral Fractures

BACKGROUND

Reasons for the increased use of closed reduction and internal fixation (CRIF) for traumatic sacral fractures (SFs) are unclear in the literature. Therefore, we aimed to report the annual changes in the number of patients, mechanisms of injury, fracture patterns, and fixation methods.

METHODS

In this retrospective study, we extracted data of 271 patients (mean age, 37.5 years) from the trauma register over an 8-year period. Annual records regarding the number of patients, injury mechanisms, fracture types, and treatment options were statistically analyzed to examine the interactions among these factors.

RESULTS

The number of patients with SFs increased significantly each year. The rate of admission to the intensive care unit after resuscitation was high (64.9%). Arbeitsgemeinschaft für Osteosynthesefragen (AO) type C pelvic ring injury (PRI), Dennis zone II injury, Roy-Camille type 2 injury, and U/H-type injury were the most common fracture types. Trans-iliac trans-sacral screws were mainly used in AO type B PRI, and their use significantly increased each year. For AO type C PRI, open reduction and internal fixation (ORIF) with rigid fixation was the main treatment, and the use of CRIF with iliosacral screws decreased each year. Stepwise statistical analysis revealed that the increase in AO type B PRI and ORIF for anterior PRI were the factors contributing to the increased use of CRIF for SFs.

CONCLUSIONS

While the use of osteosynthesis for SFs is increasing, an increased use of CRIF for traumatic SFs has also been observed in clinical practice. This increase can be attributed to the increase in AO type B PRIs and ORIF for anterior PRIs.

Assessment of regional sacral bone quality: A step towards patient-specific fracture fixation

Characterizing changes in sacral bone density could help us to inform instrumentation choices for procedures involving the sacrum. The aim of this study is to provide detailed maps of changes in sacral bone density across a series of patients using opportunistic quantitative computed tomography (QCT). We hypothesized that there would be significant differences in local cortical and trabecular bone density associated with age and sex. Fifty-four three-dimensional sacral models were segmented from routine clinical computed tomography scans, and detailed bone density estimates were derived for each bone using a calibrated opportunistic QCT approach. The effects of age and sex on cortical and trabecular bone density were determined across the sample. Overall cortical bone loss averaged 2.1 and 0.9 mg/cc per year, and trabecular bone loss was 1.6 and 0.7 mg/cc for female and males, respectively. Several regions had loss rates several times greater. Areas that were significantly affected by age included the vertebral bodies, bilateral ala, apex, and areas adjacent to both the anterior and posterior sacral foramina. Areas that were significantly affected by sex were the anterior sacral promontory, aspects of the ala. Bone density distribution across the sacrum changes nonuniformly due to factors including sex and age. Despite these overall trends, there remains significant variability between individuals. Clinical significance: This study provides detailed bone density information for both cortical and trabecular bone that could assist orthopaedic surgeons in planning surgical approaches to sacral fracture fixation.

Percutaneous sacroiliac screw fixation in fragility fractures of the pelvis: Comparison of two different augmentation techniques

OBJECTIVE

Fragility fractures of the pelvis (FFP) are becoming increasingly common. Percutaneous sacroiliac screw fixation is an accepted and safe treatment method for FFP. Augmentation is an option to optimize fixation strength of the screws. This study aims to compare patient mobility and the occurrence of complications after operative treatment of FFP utilizing two different augmentation techniques.

METHODS

All patients who received augmented sacroiliac screws for the treatment of FFPs between 01.01.2017 and 31.12.2018 at one of the two participating hospitals were included. The operative techniques only differed with regards to the augmentation method used. At the one hospital cannulated screws were used. Definitive screw placement followed augmentation. At the other hospital cannulated and fenestrated screws were used, permitting definitive screw placement prior to augmentation.

RESULTS

In total, 59 patients were included. The NRS score for pain was significantly lower after surgery. Preoperative mobility levels could be maintained or improved in 2/3 of the patients. There were no fatal complications. Two revision surgeries were performed because of screw misplacement. There were no significant differences between the two augmentation techniques in terms of complications.

CONCLUSION

Both augmentation techniques have a low complication rate and are safe methods to maintain patients' mobility level. The authors advocate early consideration of surgical treatment for patients with FFP. Augmentation can be considered a safe addition when performing percutaneous sacroiliac screw fixation.

Fragility Fractures of the Pelvis: Current Practices and Future Directions

PURPOSE OF REVIEW

To summarise the current evidence and clinical practices for patients with fragility fractures of the pelvis (FFP).

RECENT FINDINGS

FFPs are an increasingly prevalent and recognised problem in the elderly population. Recent evidence indicates they have a significant impact on function, morbidity and mortality. While traditional management of FFPs was predominantly non-surgical, surgical options have been increasingly used, with a range of surgical methods available. To date, limited consensus exists on the optimal strategy for suitable patient selection, and clinical trials in this population have proved problematic. The management of FFPs requires a multi-faceted approach to enhance patient care, including adequate pain control, minimisation of complications and optimisation of medical management. Early return to mobilisation should be a key treatment goal to maintain functional independence. The selection of patients who will maximally benefit from surgical treatment, and the most appropriate surgical strategy to employ, remains contentious.

CT of Sacral Fractures: Classification Systems and Management

CT is often performed as part of a whole-body protocol in the setting of polytrauma and is the standard of care for diagnosing and characterizing sacral fractures. These fractures are not uncommon, occurring in conjunction with pelvic ring disruption in approximately 40%-50% of patients. Knowledge of basic functional anatomy and fracture biomechanics is important in understanding sacral fracture patterns, which only rarely result from direct impact. More often, sacral fractures result from an indirect mechanism with fracture lines that propagate along relative lines of weakness, leading to predictable fracture patterns. Each fracture pattern has implications with respect to neurologic injury, spinopelvic stability, management, and potential complications. The authors explore the Denis, Roy-Camille, Isler, Robles, Sabiston-Wing, and shape-based classification systems for sacral fractures. These form the basis of the subsequently discussed unified AOSpine sacral fracture classification, a consensus system developed by spine and orthopedic surgeons as a means of improving and standardizing communication. The AOSpine sacral fracture classification also includes clinical designations for neurologic status and patient-specific modifiers. When a patient is unexaminable owing to obtundation or sedation, CT is an invaluable indirect marker of nerve compression or traction injury. It also plays an important role in visualizing and characterizing the type and extent of any associated soft-tissue injuries that may warrant a delay in surgery or an alternative operative approach. ©RSNA, 2022.

FRAGILITY FRACTURES OF THE SACRUM: A SILENT EPIDEMIC

Fragility fractures of the sacrum (FFS) are caused by low-energy trauma in the elderly population. Due to the nuanced symptomatology, many FFS remains unrecognized and the prevalence is underestimated. The clinical presentation varies, typically presenting with weightbearing low back pain without even remembering of a previous trauma. Radiographs are usually insufficient for the diagnosis and second level imaging modalities are required. In particular, magnetic resonance demonstrated the highest diagnostic accuracy. Treatment should aim to guarantee early mobilization and weightbearing, efficient pain relief and early discharge from the hospital to a proper facility for rehabilitation. Conservative treatment is reserved to non-displaced fractures with an adequate pain relief within one week allowing early mobilization. Otherwise, surgical treatment must be preferred. Nowadays, minimally invasive techniques, such as ileo-sacral screws or trans-sacral bar osteosynthesis, are safe and effective procedures and have overcome open procedures. In more complex patterns, with complete dissociation between the pelvic ring and the ilio-lumbar spine, spino-pelvic fixation is the procedure of choice.

The surgical management of highly unstable fragility fractures of the sacrum with spinopelvic dissociation: A case series and proposal of a surgical treatment algorithm

INTRODUCTION

U- and H-shaped fragility fractures of the sacrum (FFP IVb) are unstable fractures. Non-operative treatment may be associated with impaired walking abilities, chronic pain and the potential loss of independency. However, different treatment options are still controversially debated. The aim of surgical treatment includes sufficient fracture stability for immediate full weight bearing and good pain control postoperatively. A new surgical treatment algorithm was developed. This algorithm was evaluated in a cohort of geriatric patients with FFP type IVb regarding surgical complications and patient-related outcome.

METHODS

Retrospective case series. Patients ≥65 years, admitted with FFP IVb between 01/2017 and 12/2020 were included. Pelvic CT was performed and the surgical technique was chosen according to the proposed surgical treatment algorithm. For this algorithm, the technique of fracture stabilisation was adapted to sacral anatomy and the specific fracture pattern to minimize the impact of surgery and postoperative complications without compromising a sufficient fracture stability. Pain levels, complications and surgical revisions were recorded. Level of independency, walking abilities and -aids were compared 3- and 12- months postoperatively to the pre-injury situation.

RESULTS

Twenty-three patients were included. Outcome parameters could be obtained in 20 patients (85%) after three months and in 18 patients (78%) patients one year postoperatively. All patients were treated according to the algorithm. Sixteen patients received two transilio-transsacral screws (TI-TSS), whereas either lumbopelvic fixation (LPF) combined with a TI-TSS or bilateral ilio-sacral screws (ISS) was performed four times. Three patients underwent bilateral ISS into S1 with one TI-TSS into S2. Three days postoperatively, median pain VAS was 2 (0-8) compared to 7 (4-10) before surgery. One loosened TI-TSS was removed six weeks postoperatively. Three-month mortality was 14% (n=3). At one-year follow-up, all patients regained their pre-injury level of walking abilities.

CONCLUSIONS

Restoration of walking abilities, preservation of independency and efficient pain control can be achieved with surgical fixation of FFP type IVb fractures. With the proposed surgical algorithm, the fixation techniques are adapted to the fracture pattern to minimize the surgical burden.

LEVEL OF EVIDENCE

IV.

Insufficiency Fractures vs. Low-Energy Pelvic Ring Fractures - Epidemiological, Diagnostic and Therapeutic Characteristics of Fragility Fractures of the Pelvic Ring

BACKGROUND

Fragility fractures of the pelvis (FFP) encompass two fracture entities: fracture after low-energy trauma and insufficiency fracture without trauma. It is unclear whether the two subgroups differ in terms of diagnosis and therapy. The aim of this retrospective study was to evaluate insufficiency fractures with regard to defined parameters and to compare specific parameters with the fractures after low-energy trauma.

PATIENTS AND METHODS

In the period from 2008 to 2017, 203 patients with FFP were recorded at our clinic (Level 1 Trauma Centre DGU, SAV approval). Of these, 25 had an insufficiency fracture and 178 had a pelvic ring fracture after low-energy trauma. Epidemiological, diagnostic and therapeutic parameters were examined.

RESULTS

There was a relative increase in the insufficiency fracture within the FFP (2008 - 2009: 5.0% vs. 2015 - 2017: 17.8%). In these patients, osteoporosis tended to be more pronounced than in patients after low-energy trauma (t-value: - 3.66 vs. - 3.13). The diagnosis of insufficiency fractures showed increased use of MRI and DECT (60.9% vs. 26.0%) and a high proportion of type IV fractures after FFP (40.0% vs. 7.9%). In terms of therapy, surgical treatment of the insufficiency fracture was sought more often (68,2% vs. 52,1%), with a tendency towards increased use of combined osteosynthesis procedures (14.3% vs. 7.6%).

CONCLUSION

We were able to show that as the number of cases increases, the insufficiency fracture becomes more important within FFP. If these patients tend to have more pronounced osteoporosis, particular attention should be paid to the diagnosis and adequate therapy of the osteoporosis, especially in the case of an insufficiency fracture. In addition to the increased diagnostic testing using MRI and DECT to detect oedema and the increased surgical therapy for this type of fracture, it is also noteworthy that the insufficiency fracture can cause higher-grade fractures after FFP.

Distal sacral nerve roots severed by a fragility fracture of the sacrum: a case report

Background

Owing to the aging population, fragility fractures of the pelvis are occurring more frequently. Fixation of the fracture and stabilization of the pelvic ring usually provide good clinical results. A case of distal sacral nerve roots severed by a fragility fracture of the sacrum is presented.

Case presentation

A 62-year-old Japanese woman with schizophrenia with low back pain, gait disorder, dysuria, and fecal incontinence presented to an emergency department, and plain X-rays showed no findings. She also complained of dysuria, and neurogenic bladder and cystitis were diagnosed. One month later, she was admitted to a psychiatric hospital for exacerbation of schizophrenia. In hospital, she had a urethral catheter inserted and spent 3 months in bed. She was referred to our orthopedic department because a gait disorder was discovered after her mental condition improved and she was permitted to walk. On examination, she could not walk and had decreased sensation from the buttocks to both posterior thighs and around the anus and perineum. Manual muscle testing of her lower limbs showed mild weakness of about 4 in bilateral flexor hallucis longus and gastrocnemius, and bilateral Achilles tendon reflexes were lost. Her anal sphincter did not contract, and urinary retention continued after urethral catheter removal. Imaging examinations showed an H-shaped sacral fracture consisting of a transverse fracture with displacement of the third sacral vertebra and vertical fractures of the bilateral sacral wings, with severe stenosis of the spinal canal at the site of the transverse fracture. The patient was diagnosed as having bladder and rectal dysfunction due to a displaced, unstable sacral fracture. First to third sacral laminectomy and alar–iliac fixation using percutaneous pedicle screws and sacral alar–iliac screws were then performed. The bilateral distal sacral nerve roots (S3, S4, S5) were completely severed at the second to third sacral levels, but bilateral second sacral nerve roots were not compressed from the bifurcation to the sacral foramen. Postoperatively, bladder and rectal dysfunction remained, but the low back pain was alleviated. Two weeks postoperatively, she could walk with a walker and was discharged. Three months after the operation, bone fusion of the fracture was observed.

Conclusions

In cases of bladder–rectal dysfunction with low back pain, the possibility of sacral fracture should be considered, and computed tomography, magnetic resonance imaging, and X-ray examinations should be performed. Even sacral fractures without displacement require attention because they can cause serious injury in the event of a nerve root being severed if not diagnosed early and given appropriate treatment.

Focusing on individual morphological fracture characteristics of pelvic ring fractures in elderly patients can support clinical decision making

Introduction

Pelvic ring fractures in the elderly are often caused by minor trauma. Treatment of these patients is currently based on fracture classification, clinical course, and ability to mobilize. Our aim was to identify morphological fracture characteristics with potential prognostic relevance and evaluate their association with clinical decision making and outcome, as well as their interobserver reliability.

Methods

Five fracture characteristics were investigated as potential variables: 1. Extent of the dorsal pelvic ring fracture (absent, unilateral, bilateral); 2. Extent of the ventral pelvic ring fracture (absent, unilateral, bilateral); 3. Presence of a horizontal sacral fracture; 4. Ventral dislocation; 5. Ventral comminution.

These characteristics were assessed retrospectively in a series of 548 patients. The association of their presence with the decision to perform surgery, failure of conservative treatment and the length of hospital stay (LOS) was determined. Further, the inter-observer reliability for the specific characteristics was calculated and the relation with survival assessed.

Results

Four of the five evaluated characteristics showed an association with clinical decision making and patient management. In particular the extent of the dorsal fractures (absent vs. unilateral vs. bilateral) (OR = 7.0; p < 00.1) and the presence of ventral comminution/dislocation (OR = 2.4; p = 0.004) were independent factors for the decision to perform surgery. Both the extent of the dorsal fracture (OR = 1.8; p < 0.001) and the presence of ventral dislocation (OR = 1.7; p = 0.003) were independently associated with a prolonged overall LOS.

The inter-observer agreement for the fracture characteristics ranged from moderate to substantial.

A relevant association with increased mortality was shown for horizontal sacral and comminuted ventral fractures with hazard ratios (HR) of 1.7 (95% CI: 1.1, 2.5; p = 0.008) and HR = 1.5 (95% CI: 1.0, 2.2; p = 0.048).

Conclusion

In the elderly, the extent of the dorsal fractures and the presence of ventral comminution/dislocation were associated to the decision to undergo surgery, failure of conservative treatment and length of stay. Survival was related to horizontal sacral fractures and ventrally comminuted fractures. These characteristics thus represent a simplified but highly informative approach for the evaluation of pelvic ring fractures in the elderly. This approach can support clinical decision making, promote patient-centred treatment algorithms and thus improve the outcome of individualized care.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-022-03222-0.

[Sacral fractures in geriatric patients]

Sacral fractures in geriatric patients are increasing and form a distinct entity. Clinical findings can be unspecific, which is why they are easily overlooked. It is mandatory to analyze the whole pelvic ring for evaluation of pelvic stability and for making treatment decisions. The primary diagnostics are made using plain X‑radiography; however, for assessment of the posterior pelvic ring an examination using sectional imaging is regularly necessary. The fragility fractures of the pelvis (FFP) classification is suitable as a guideline for the surgical treatment to be used. Stable fractures without relevant displacement after initial mobilization should be treated conservatively. Instability, failure of mobilization and persistent pain are, however, common reasons for surgical treatment. Fracture displacement determines if minimally invasive procedures for posterior and anterior pelvic ring stabilization are possible. Otherwise, complex open procedures such as spinopelvic fixation may be necessary.

Additional clinical value of routine CT imaging in fragility fractures of the pelvis: a prospective cohort study (ARTIFACT)

PURPOSE

Additional CT imaging for fragility fractures of the pelvis (FFP) has a high detection rate for concomitant posterior ring fractures (cPRFs). However, the clinical value of routine additional CT imaging is unknown. This study aimed to determine the additional clinical value of routine CT imaging by changes in treatment policy and to establish the predictive value of pain localized around the sacroiliac joint (SIJ) for cPRFs.

METHODS

A prospective cohort study was conducted in a single teaching hospital in the Netherlands between November 2019 and November 2020. Patients were included if they were ≥ 65 years and had a (suspected) FFP on the pelvic radiograph. All patients underwent additional CT imaging. Changes in treatment policies ((possible) surgery, restrictive weight-bearing, hospital admission and outpatient follow-up) after CT imaging were registered.

RESULTS

Fifty-one patients (44 female) were included with a mean age of 80.6 years. Routine CT imaging revealed an additional cPRF in 27 patients (53%). A change in treatment occurred in 29 patients (57%), of which 7 (12%) were managed either surgical or with restrictive weight-bearing. The presence of pain around the SIJ had a sensitivity of 89% and specificity of 61% for detecting a cPRF.

CONCLUSION

Routine additional CT imaging has few direct therapeutic consequences with regards to surgical management or restrictive weight-bearing. These findings may be altered when considering a lower threshold for surgical intervention. The presence of pain around the SIJ was highly predictive for a clinically relevant cPRF.

TRIAL REGISTRATION

NL8011 on 02-09-2019.

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

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

What is the long-term clinical outcome after fragility fractures of the pelvis? - A CT-based cross-sectional study

BACKGROUND

Recently, Rommens and Hoffman introduced a CT-based classification system for fragility fractures of the pelvis (FFP). Although fracture characteristics have been described, the relationship with clinical outcome is lacking. The purpose of this study was to get insight into the type of treatment and subsequent clinical outcome after all types of FFP.

METHODS

A cross-sectional cohort study was performed including all elderly patients (≥ 65 years) with a CT-diagnosed FFP, between 2007-2019 in two level 1 trauma centers. Data regarding treatment, mortality and clinical outcome was gathered from the electronic patient files. Patients were asked to complete patient-reported outcome measures (PROMs) regarding physical functioning (SMFA) and quality of life (EQ-5D). Additionally, a standardized multidisciplinary treatment algorithm was constructed.

RESULTS

A total of 187 patients were diagnosed with an FFP of whom 117 patients were available for follow-up analysis and 58 patients responded. FFP type I was most common (60%), followed by type II (27%), type III (8%) and type IV (5%). Almost all injuries were treated non-operatively (98%). Mobility at six weeks ranged from 50% (type III) to 80% type II). Mortality at 1 year was respectively 16% (type I and II), 47% (type III) and 13% (type IV). Physical functioning (SMFA function index) ranged from 62 (type III and IV) to 69 (type II) and was significantly decreased (P=<0.001) compared to the age-matched general population. Quality of life was also significantly decreased, ranging from 0.26 (type III) to 0.69 (type IV).

CONCLUSIONS

FFP type I and II are most common. Treatment is mainly non-operative, resulting in good mobility after six weeks, especially for patients with FFP type I and II. Mortality rates at one year were substantial in all patients. Physical functioning and quality of life was about 20-30% decreased compared to the general population.

Self-rated health status and activities of daily living in the first 12 months after fragility fractures of the pelvis-a prospective study on 134 patients

The aim of this study was to evaluate changes in activities of daily living and self-reported health status in the first year after fragility fractures of the pelvis. We found out that these fractures lead to a significant, long-lasting deterioration of both parameters, comparable with hip fractures.

PURPOSE

The aim of this prospective study was to evaluate the development and to identify influencing factors in activities of daily living (ADL) and self-reported health status (HS) in the first year after fragility fractures of the pelvis (FFP).

METHODS

A total of 134 patients with FFP ≥ 60 years were included. ADL were measured using the Barthel index (BI) and the IADL scale pre-fracture, at 6 weeks, 6 months, and 12 months. HS was evaluated using the EQ-5D questionnaire at 6 weeks, 6 months, and 12 months. Multiple regression analysis and hierarchical linear models were applied to identify influencing factors in ADL and HS.

RESULTS

The BI was 95 pre-fracture, 75 at 6 weeks (p < 0.001), 80 at 6 months (p = 0.178), and 80 at 12 months (p = 0.149). The IADL was 6 pre-fracture, 3 at 6 weeks (p < 0.001), 4 at 6 months (p = 0.004), and 4 at 12 months (p = 0.711). The EQ-5D index was 0.70 at 6 weeks, 0.788 at 6 months (p = 0.158), and 0.788 at 12 months (p = 0.798). Significant influencing factors in the multiple regression analysis were pre-fracture nursing care level for all scores; pre-fracture mobility for BI; and pre-fracture IADL, ASA score, and age for IADL. Significant influencing factors in the hierarchical linear model were pre-fracture nursing care level for all scores; pre-fracture IADL, ASA score, age, and time for IADL; and pre-fracture mobility, sex, and time for the EQ-5D.

CONCLUSION

Our results confirm that FFP lead to a significant, long-lasting deterioration in ADL and HS, comparable with hip fractures.

Minimally Invasive "Crab-Shaped Fixation" for Treating Patients with Fragility Fractures of the Pelvis

Introduction

In the aging society, fragility fracture of the pelvis (FFP) has become a problem. Although strong and minimally invasive fixation is required in FFP surgery, reports on relevant surgical results are scarce. Crab-shaped fixation (CSF) is a spinopelvic fixation that involves reconstruction of the posterior pelvic ring using spinal instrumentation. This study aimed to evaluate the walking ability and perioperative complications of patients who underwent CSF for FFP.

Methods

We included patients diagnosed with unstable FFPs, including sacral fracture, who required hospitalization. Demographic data, such as age, sex, bone mineral density, and Rommens classification, were evaluated. Surgical findings included estimated blood loss, operation time, and perioperative complications. The improvement in postoperative walking ability was evaluated based on the length of the postoperative period before the initiation of walker training and whether walking aids were required at 6 months post-surgery, compared with those who received conservative treatment for FFP.

Results

Our study included 6 cases that received CSF and 16 cases that received conservative treatment, in which all were females and presented with sacral fractures. The average age of the surgical patients, the operation time, and the estimated blood loss were 79.5±14.7 years, 180.7±28.7 min, and 124.2±29.4 mL, respectively. The average length of the postoperative period prior to the initiation of walker training was 10.8±12.3 days, which was significantly shorter than that of conservative treatment. With regard to perioperative complications, poor reduction of fracture dislocation was observed in one case as well as surgical site infection in another case, but the walking ability improved in all cases.

Conclusions

We evaluated the results of the posterior pelvic ring reconstruction with CSF for patients with vertically unstable FFPs, including sacral fractures. CSF is minimally invasive and would be useful as it allowed walker training during the early postoperative period, which improved patients' walking ability even during the in situ pelvic ring reconstruction.

The Influence of Surgeon Experience and Subspeciality on the Reliability of the AO Spine Sacral Classification System

STUDY DESIGN

Cross-sectional survey.

OBJECTIVE

To determine the influence of surgeons' level of experience and subspeciality training on the reliability, reproducibility, and accuracy of sacral fracture classification using the Arbeitsgemeinschaft für Osteosynthesefragen Spine Sacral Classification System.

SUMMARY OF BACKGROUND DATA

A surgeons' level of experience or subspecialty may have a significant effect on the reliability and accuracy of sacral classification given various levels of comfort with imaging assessment required for accurate diagnosis and classification.

METHODS

High-resolution computerized tomography (CT) images from 26 cases were assessed on two separate occasions by 172 investigators representing a diverse array of surgical subspecialities (general orthopedics, neurosurgery, orthopedic spine, orthopedic trauma) and experience (<5, 5-10, 11-20, >20 yrs). Reliability and reproducibility were calculated with Cohen kappa coefficient (k) and gold standard classification agreement was determined for each fracture morphology and subtype and stratified by experience and subspeciality.

RESULTS

Respondents achieved an overall k = 0.87 for morphology and k = 0.77 for subtype classification, representing excellent and substantial intraobserver reproducibility, respectively. Respondents from all four practice experience groups demonstrated excellent interobserver reliability when classifying overall morphology (k = 0.842/0.850, Assessment 1/Assessment 2) and substantial interobserver reliability in overall subtype (k = 0.719/0.751) in both assessments. General orthopedists, neurosurgeons, and orthopedic spine surgeons exhibited excellent interobserver reliability in overall morphology classification and substantial interobserver reliability in overall subtype classification. Surgeons in each experience category and subspecialty correctly classified fracture morphology in over 90% of cases and fracture subtype in over 80% of cases according to the gold standard. Correct overall classification of fracture morphology (Assessment 1: P = 0.024, Assessment 2: P = 0.006) and subtype (P2 < 0.001) differed significantly by years of experience but not by subspecialty.

CONCLUSION

Overall, the Arbeitsgemeinschaft für Osteosynthesefragen spine sacral classification system appears to be universally applicable among surgeons of various subspecialties and levels of experience with acceptable reliability, reproducibility, and accuracy.Level of Evidence: 4.

Artificial intelligence and CT-based 3D statistical modeling to assess transsacral corridors and plan implant positioning

Transsacral corridors at levels S1 and S2 represent complex osseous spaces allowing percutaneous fixation of non- or minimally-displaced fragility fractures of the sacrum. To safely place transsacral implants, they must be completely intraosseous. However, standard radiographs and CT do not properly demonstrate the corridor's intricate configuration. Our goal was to facilitate the three-dimensional assessment of transsacral corridors using artificial intelligence and the planning of transsacral implant positioning. In total, 100 pelvic CTs (49 women, mean age: 58.6 ± SD 14.8 years; 51 men, mean age: 60.7 ± SD 13 years) were used to compute a 3D statistical model of the pelvic ring. On the basis of morphologic features (=predictors) and principal components scores (=response), regression learners were interactively trained, validated, and tuned to predict/sample personalized 3D pelvic models. They were matched via thin-plate spline transformation to a series of 20 pelvic CTs with fragility fractures of the sacrum (18 women and 2 men, age: 69-9.5 years, mean age: 78.65 ± SD 8.4 years). These models demonstrated the availability, dimension, cross-section, and symmetry of transsacral corridors S1 and S2, as well as the planned implant position, dimension, axes, and entry and exit points. The complete intraosseous pathway was controlled in CT reconstructions. We succeeded to establish a workflow determining transsacral corridors S1 and S2 using artificial intelligence and 3D statistical modeling.

OF-Pelvis classification of osteoporotic sacral and pelvic ring fractures

Objectives

Osteoporotic fractures of the pelvis (OFP) are an increasing issue in orthopedics. Current classification systems (CS) are mostly CT-based and complex and offer only moderate to substantial inter-rater reliability (interRR) and intra-rater reliability (intraRR). MRI is thus gaining importance as a complement.

This study aimed to develop a simple and reliable CT- and MRI-based CS for OFP.

Methods

A structured iterative procedure was conducted to reach a consensus among German-speaking spinal and pelvic trauma experts over 5 years. As a result, the proposed OF-Pelvis CS was developed. To assess its reliability, 28 experienced trauma and orthopedic surgeons categorized 25 anonymized cases using X-ray, CT, and MRI scans twice via online surveys. A period of 4 weeks separated the completion of the first from the second survey, and the cases were presented in an altered order. While 13 of the raters were also involved in developing the CS (developing raters (DR)), 15 user raters (UR) were not deeply involved in the development process.

To assess the interRR of the OF-Pelvis categories, Fleiss’ kappa (κ_F) was calculated for each survey. The intraRR for both surveys was calculated for each rater using Kendall’s tau (τ_K). The presence of a modifier was calculated with κ_F for interRR and Cohen’s kappa (κ_C) for intraRR.

Results

The OF-Pelvis consists of five subgroups and three modifiers. Instability increases from subgroups 1 (OF1) to 5 (OF5) and by a given modifier. The three modifiers can be assigned alone or in combination.

In both surveys, the interRR for subgroups was substantial: κ_F = 0.764 (Survey 1) and κ_F = 0.790 (Survey 2). The interRR of the DR and UR was nearly on par (κ_F Survey 1/Survey 2: DR 0.776/0.813; UR 0.748/0.766). The agreement for each of the five subgroups was also strong (κ_F min.–max. Survey 1/Survey 2: 0.708–0.827/0.747–0.852). The existence of at least one modifier was rated with substantial agreement (κ_F Survey 1/Survey 2: 0.646/0.629).

The intraRR for subgroups showed almost perfect agreement (τ_K = 0.894, DR: τ_K = 0.901, UR: τ_K = 0.889). The modifier had an intraRR of κ_C = 0.684 (DR: κ_C = 0.723, UR: κ_C = 0.651), which is also considered substantial.

Conclusion

The OF-Pelvis is a reliable tool to categorize OFP with substantial interRR and almost perfect intraRR. The similar reliabilities between experienced DRs and URs demonstrate that the training status of the user is not important. However, it may be a reliable basis for an indication of the treatment score.

'Within Ring' Concept Treatment for Displaced H-Shaped Type IVb Fragility Fractures of the Pelvis

Introduction

Sacroiliac rod fixation (SIRF) preserves the mobility of L5/S1 (lumber in the pelvis), as a surgical procedure for high-energy pelvic ring fractures. The concept of SIRF method without pedicle screws into L4 and L5 is called ‘within ring' concept. Case Presentation. We report here the clinical results of ‘within ring' concept treatment with sacroiliac rod fixation for a case of displaced H-shaped Rommens and Hofmann classification type IVb fragility fractures of the pelvis (FFP), which A 79-year-old woman had been difficult to walk due to pain that had been prolonged for more than one month since her injury. The patient was successfully treated with SIRF, no pain waking with a walking stick and returned to most social activities including living independently within 6 months of the operation.

Conclusion

SIRF is useful because it can preserve the mobility in the lumbar pelvis; not including the lumbar spine in the fixation range like spino pelvic fixation is a simple, safe, and low-invasive internal fixation method for displaced H-shaped type IVb fragility fractures of the pelvis.

Short-term outcome of fragility fractures of the pelvis in the elderly treated with screw osteosynthesis and external fixator

Background

The treatment of fragility fractures of the pelvis is rising challenge for orthopedic trauma surgeons. Operative treatment should allow immediate full weight bearing and early mobilisation but should also be as minimal invasive as possible. Sacroiliac (SI) or transsacral transiliac screws (TSTI) alone or depending on the fracture in combination with an external fixator meets both of these criteria.

Material and methods

The outcome of 121 operatively treated patients with fragility fractures of the pelvis were evaluated in this retrospective study. Depending on the type of fracture the patients were treated with navigated SI screw or TSTI screw alone or in combination with an external fixator. All patients were operated in supine position in a hybrid-OR, which consists of a fixed robotic 3D flatpanel detector (Artis zeego, Siemens Healthineers, Germany) and a navigation system (BrainLab Curve, BrainLab, Germany).

Results

37 patients were treated with either one or two SI screws and 57 with one TSTI screw. An additional external fixator was combined with SI screws in 17 patients and with TSTI screws in 10 patients. The preoperative pain score was significantly higher compared to the postoperative score (5.1 ± 2.5 vs 2.2 ± 1.9, p < 0.05). Follow-up at 6 month was possible for 106 patients which showed screw loosening in 16.3% of the SI Screws (n = 49) compared to only 5.2% of TSTI screws (n = 57). No screw loosening was seen in the combination of TSTI-screw and external fixator (n = 10). There were two septic and three aseptic pin loosenings of the external fixator. Overall only one patient needed revision surgery due to screw loosening and local irritation. Overall 75.2% (n = 91) of the patients could be released in their home or in a rehabilitation unit and only 14% (n = 17) were released to a nursing home due to immobility despite the operation. Non-surgical complications rate was 21.5%.

Conclusion

SI or TSTI screws with possible combination with an external fixator show early pain relief and allows most of the patients to keep their former level of independence. With an also low surgical complication rate, it proved to be a safe and reliable treatment for fragility fractures of the pelvis. Due the effective pain relief and the minimal invasive approach, early mobilisation is possible and might prevent typical non-surgical complications which are very common during conservative treatment.

Current Minimally Invasive Surgical Concepts for Sacral Insufficiency Fractures

An increasing incidence of sacral insufficiency fractures in geriatric patients has been documented, representing a major challenge to our healthcare system. Determining the accurate diagnosis requires the use of sectional imaging, including computed tomography and magnetic resonance imaging. Initially, non-surgical treatment is indicated for the majority of patients. If non-surgical treatment fails, several minimally invasive therapeutic strategies can be used, which have shown promising results in small case series. These approaches are sacroplasty, percutaneous iliosacral screw fixation (S1 with or without S2), trans-sacral screw fixation or implantation of a trans-sacral bar, transiliac internal fixator stabilisation, and spinopelvic stabilisation. These surgical strategies and their indications are reported in detail. Generally, treatment-related decision making depends on the clinical presentation, fracture morphology, and attending surgeon's experience.

ASSERT (Acute Sacral inSufficiEncy fractuRe augmenTation): Perceptions in the Assessment and Treatment of Pubic Rami and Sacral Fragility Fractures Amongst Healthcare Professionals in Geriatric Medicine and Surgery-A Qualitative Study

Background:

Pubic rami fragility fractures are common in older people and result in significant morbidity and increased mortality. Co-existing fractures of the sacrum are common, but routinely missed. The aim of the study was to explore the perceptions in the assessment and treatment of pubic rami and sacral fragility fractures amongst healthcare professionals.

Methods:

We interviewed 14 participants about their experience in the assessment and treatment of patients presenting with pubic rami fragility fractures. Data was analyzed using an inductive thematic approach.

Results:

The majority of patients presenting with a pubic rami fragility fracture were managed by geriatricians. However, many of the geriatricians were not aware that these fractures have a high association with co-existing sacral fragility fractures. Furthermore, they were not aware of the limitations of standard x-ray imaging, nor of the potential benefits of surgical intervention for sacral fragility fractures. Spinal surgeons recommended that early, more specialist imaging in patients with pubic rami fragility fractures failing to mobilize, would change clinical management, if found to have a coexisting sacral fragility fracture, amenable to surgical intervention.

Conclusions:

The awareness, assessment and management of sacral fragility fractures in patients presenting with pubic rami fragility fractures is poor amongst healthcare professionals in geriatric medicine. Spinal surgeons in this study advocate early further imaging and surgical intervention in patients confirmed to have a concomitant sacral fragility fracture who are failing to mobilize.

Operative treatment of fragility fractures of the pelvis is connected with lower mortality. A single institution experience

Background

Fragility fractures of the pelvis (FFP) represent an increasing clinical entity. Until today, there are no guidelines for treatment of FFP. In our center, recommendation for operative treatment was given to all patients, who suffered an FFP type III and IV and to patients with an FFP type IIwith unsuccessful non-operative treatment. We performed a retrospective observational study and investigated differences between fracture classes and management alternatives. We hypothetized that operative treatment may reduce mortality.

Materials and methods

The medical charts and radiographs of 362 patients were analysed. Patient demographics, FFP-classification, length of hospital stay (LoS), type of treatment, general and surgery-related complications, mortality, Short Form-8 physical component score (SF-8 PCS) and mental component score (SF-8 MCS), Parker Mobility Score (PMS) and Numeric Rating Scale (NRS) were documented.

Results

238 patients had FFP type II and 124 FFP type III and IV. 52 patients with FFP type II (21.8%) and 86 patients with FFP type III and IV (69.4%) were treated operatively (p<0.001). Overall mortality did not differ between the fracture classes (p = 0.127) but was significantly lower in the operative group (p<0.001). Median LoS was significantly higher in FFP type III and IV (p<0.001) and in operated patients (p<0.001). There were more in-hospital complications in patients with FFP type III and IV (p = 0.001) and in the operative group (p = 0.006). More patients of the non-operative group were mobile (p<0.001) and independent (p<0.001) at discharge. Half of the patients could not return in their living environment.203 of the 235 surviving patients (86%) answered the questionnaires after a mean follow-up time of 38 months. SF-8 PCS, SF-8 MCS and PMS did not differ between the fracture classes and treatment groups. Pain perception was higher in the operated group (p = 0.013).

Conclusion

In our study, we observed that operative treatment of FFP provides low mortality rates, although LoS and in-hospital complications were higher in the operative group. At discharge, the non-operative group was more mobile and independent. At follow up, quality of life and mobility were comparable between the groups. Further prospective studies are needed to clarify the impact of operative treatment of FFP on mortality and functional outcome.

Biomechanical Effects of a Cross Connector in Sacral Fractures - A Finite Element Analysis

Background: Spinopelvic fractures and approaches of operative stabilization have been a source of controversial discussion. Biomechanical data support the benefit of a spinopelvic stabilization and minimally invasive procedures help to reduce the dissatisfying complication rate. The role of a cross connector within spinopelvic devices remains inconclusive. We aimed to analyze the effect of a cross connector in a finite element model (FE model). Study Design: A FE model of the L1-L5 spine segment with pelvis and a spinopelvic stabilization was reconstructed from patient-specific CT images. The biomechanical relevance of a cross connector in a Denis zone I (AO: 61-B2) sacrum fracture was assessed in the FE model by applying bending and twisting forces with and without a cross connector. Biomechanical outcomes from the numerical model were investigated also considering uncertainties in material properties and levels of osseointegration. Results: The designed FE model showed comparable values in range-of-motion (ROM) and stresses with reference to the literature. The superiority of the spinopelvic stabilization (L5/Os ilium) ± cross connector compared to a non-operative procedure was confirmed in all analyzed loading conditions by reduced ROM and principal stresses in the disk L5/S1, vertebral body L5 and the fracture area. By considering the combination of all loading cases, the presence of a cross connector reduced the maximum stresses in the fracture area of around 10%. This difference has been statistically validated (p < 0.0001). Conclusion: The implementation of a spinopelvic stabilization (L5/Os ilium) in sacrum fractures sustained the fracture and led to enhanced biomechanical properties compared to a non-reductive procedure. While the additional cross connector did not alter the resulting ROM in L4/L5 or L5/sacrum, the reduction of the maximum stresses in the fracture area was significant.

Atraumatic fractures of the femur

Atraumatic fractures of femur, although not as common as traumatic fractures, are frequently encountered in the clinical practice. They present with non-specific symptoms and can be occult on initial imaging making their diagnosis difficult, sometimes resulting in complications. Overlapping terminologies used to describe these fractures may hamper effective communication between the radiologist and the clinician. In this article, we review various atraumatic fractures of femur, terminologies used to describe them, their imaging findings and differential diagnosis. The article also describes the aetiology, pathophysiology and relevant biomechanics behind these fractures. An approach to atraumatic femoral fractures has been outlined.

Fracture progression in fragility fractures of the pelvis: A case report

Introduction

Fragility fractures of the pelvis (FFP) are becoming increasingly common as our population ages. Usually treated conservatively the concept of fracture progression is little recognized but can have important consequences for the patient if missed.

Case report

A patient with a FFP presented with increase of pain after initial conservative treatment. Additional imaging revealed extensive fracture progression resulting in an unstable pelvic ring, requiring surgical intervention. Most FFPs are currently treated conservatively. However, initially stable FFPs can progress into more unstable fracture patterns that may require invasive treatment.

Conclusion

Physicians should be aware of fracture progression and concomitant posterior ring fractures in case of prolonged or recurrent pain or mobilization difficulties. Careful follow-up and awareness might help to prevent or treat debilitation in an early phase and improve outcomes.

Delayed Displacement of a Subtle Sacral Insufficiency Fracture Unmasking Lumbopelvic Instability: A Case Report

CASE

There is limited literature reporting on sacral insufficiency fractures as a cause of lumbopelvic instability. We describe the presentation, treatment, and clinical outcome with a 2-year follow-up of a woman who sustained a low-energy spinopelvic dissociation diagnosed with magnetic resonance imaging. There was significant delayed displacement, and the patient was treated surgically with percutaneous iliosacral and trans-sacral screws.

CONCLUSION

U-type sacral insufficiency fractures may be subtle on advanced imaging and must be followed closely if nonoperative treatment is chosen. These patients may require surgical intervention. Iliosacral screws and lumbopelvic fixation are treatment options, each with advantages and disadvantages.

Sacral fractures: An updated and comprehensive review

Sacral fractures are often underdiagnosed but are relatively frequent in the setting of pelvic ring injury. Causes include traumatic insults and osteoporosis. Sacral fractures have become more frequent owing to the growth of the elderly population worldwide as osteoporosis is an age-related disease. Misdiagnosed and neglected sacral fractures can result in chronic back pain, spine deformity, and instability. Unfortunately, the wide range of classification systems hinders adequate communication among clinicians. Therefore, a complete understanding of the pathology, and communication within the interdisciplinary team, are necessary to ensure adequate treatment and satisfactory clinical outcomes. The aim of this manuscript is to present the current knowledge available regarding classification systems, clinical assessment, decision-making factors, and current treatment options.

Anatomical variations of the sacro-iliac joint: a computed tomography study

PURPOSE

To identify, describe, and compare the prevalence of sacroiliac joint anatomical variants.

METHODS

A retrospective study was performed on computed tomography scans. Joint space was measured, and variants were classified as accessory joint, ileosacral complex, bipartite bony plate, semicircular defect, iliac bony plate, and ossification centers.

RESULTS

400 scans were analyzed. Mean age was 49 years, 180 men (45%), and 220 women (55%). 209 (52.2%) patients presented an anatomical variant with higher prevalence in women (65.4% vs 36.2%), and those older than 40 years of age (60% vs 40%). Mean joint space was similar bilaterally (right 2.41 ± 0.65 mm vs. left 2.37 ± 0.65 mm). Prevalence was: 19.8% accessory joint, 6.5% ileosacral complex, 12.3% bipartite bony plate, 8% semicircular defect, 5% iliac bony plate, and 0.8% for ossification centers.

CONCLUSION

Prevalence of anatomical variants of the SIJ is higher in the Hispanic population, women, and those older than 40 years.