Sacral fractures: issues, challenges, solutions

Is Osteoporosis an Independent Risk Factor for Sacral Fracture after Lumbosacral Spinal Fusion in Adults? A Retrospective Cohort Study

BACKGROUND CONTEXT

Sacral fracture is a rare complication following lumbosacral fusion in adults linked to post-surgical biomechanical changes. There are mixed research results suggesting that osteoporosis may or may not be a contributing factor.

PURPOSE

To determine if osteoporosis is an independent risk factor for sacral fracture after lumbosacral fusion.

STUDY DESIGN

A propensity-matched retrospective cohort study that was pre-registered on Open Science Framework PATIENT SAMPLE: After matching, patients (n=14,302; 82% female) who underwent lumbosacral fusion had a mean age of 64 years and were divided into the osteoporosis cohort (n=7,151) or the no osteoporosis cohort (n=7,151).

OUTCOME MEASURES

The primary outcome measure was the risk ratio (RR) of sacral fracture through two years after lumbosacral fusion. We secondarily explored the RR for pelvic fixation with instrumentation. We assessed negative control outcomes such as further imaging and major trauma, targeting near-null point estimates.

METHODS

We included adults (≥18 years old) in the TriNetX database from 2005-2023 who underwent primary lumbosacral fusion, divided into two cohorts depending on the presence or absence of osteoporosis (i.e., osteoporosis and no osteoporosis cohorts) and propensity matched via key risk factors.

RESULTS

There were 261 (1.8%) sacral fractures in the entire patient population (n=14,302). Comparing the osteoporosis cohort to no osteoporosis cohort, there was a statistically significant increase in risk of sacral fracture (RR: 1.75 [1.36, 2.24]; p<0.001; 166 [2.3%] versus 95 [1.3%] cases), with a median time to event of 154 and 181 days in each cohort, respectively. There was also a statistically significant increase in risk of pelvic fixation with instrumentation (RR: 1.87 [1.25, 2.78]; p=0.002). The likelihood of polytrauma (RR=0.98), subdural hemorrhage (RR=1.24), and diagnostic imaging (RR: 930) approximated the null between cohorts, suggesting findings would not be explained by differences in these variables.

CONCLUSION

Osteoporosis appears to be independently associated with a statistically and clinically significant risk of sacral fracture through two years after lumbosacral fusion. Further research may be warranted for corroboration.

Innovating Pelvic Fracture Surgery: Development and Evaluation of a New Surgical Table for Enhanced C-Arm Imaging and Operational Efficiency

Background: Pelvic fractures require precise reduction and stabilization, necessitating high-quality C-arm imaging and accurate patient positioning. Standard operating tables often obstruct optimal C-arm maneuverability. To address this, we developed a new auxiliary surgical table that integrates with existing tables and evaluated its clinical utility compared to a specialized carbon surgical table. Methods: Between March 2018 and June 2023, we conducted a retrospective study involving 162 patients (97 men and 65 women; average age 45.7 years) who underwent percutaneous sacroiliac screw fixation for pelvic fractures. Ninety patients were treated using the newly developed table, and seventy-two patients were treated using the carbon table. The new table, measuring 200 cm in length, 50 cm in width, and 2 cm in thickness, was constructed from waterproof plywood and designed to be securely attached to existing operating tables. We compared surgical preparation times, economic costs, and intraoperative imaging feasibility between the two groups. Results: Use of the new table significantly reduced the surgical preparation time by an average of 21 min and saved approximately $43,000 in cost compared to the carbon table. Subjective assessments indicated no notable difference in intraoperative C-arm image quality between the two groups. The new table allowed free C-arm rotation by overcoming the mechanical limitations of conventional tables. Conclusions: The new auxiliary table demonstrated clinical feasibility and economic advantages without compromising intraoperative imaging quality, offering a practical and cost-effective alternative for pelvic fracture surgeries.

Research Trends and Hotspots Evolution of Nerve Decompression: A Bibliometric Analysis From 2005 to 2024

BACKGROUND

The incidence of nerve entrapment-related diseases, caused by a variety of factors, has been increasing annually, significantly impairing patients' quality of life. Nerve decompression serves as one of the critical approaches for treating such conditions. However, there remains a scarcity of bibliometric analyses within the field of nerve decompression.

METHODS

The publications related to nerve decompression in the Web of Science database from 2005 to 2024 were collected. Bibliometric methods were used to analyze the basic components of publications, synthesize research trends, and predict future research hotspots.

RESULTS

A total of 606 publications were included in our study, with the number of publications ranging from 16 in 2005 to 52 in 2024. In terms of countries, the United States occupies a central position in both the number of publications (213 publications) and the quality (H-index = 34) and works closely with other countries. In terms of publishing institutions, Shanghai Jiao Tong University has the largest number of 18 publications. Acta Neurochirurgica is the journal with the highest number of 27 publications. The focus of research in this field can be divided into 3 main categories: cranial nerves, upper limb nerves, and lower limb nerves. The topic of research has gradually transferred to the lower limb nerve, and the keyword sacral nerve will be a hot topic in this field.

CONCLUSIONS

This is the first bibliometric study to comprehensively summarize trends and hotspots in nerve decompression research. Our findings shed light on future research directions, international collaborations, and interdisciplinary relationships. The sacral nerve has emerged as a current and potential future research hotspot, warranting further exploration.

Percutaneous spinopelvic fixation technique using external fixation for focal kyphosis reduction in U-type sacral fractures: a case report

Background

Sacral fractures, particularly U-type fractures characterized by a transverse fracture line, result in significant instability and deformity, including focal kyphosis. These fractures challenge biomechanical integrity and neural structures, often leading to long-term disability if not corrected. Surgical approaches vary, but percutaneous spinopelvic fixation offers benefits like reduced soft tissue trauma and expedited recovery. This case report highlights managing a displaced U-type sacral fracture with focal kyphosis using a percutaneous spinopelvic reduction technique followed by fixation, demonstrating its efficacy and potential benefits.

Case Description

A 30-year-old female with a complex medical history, including opioid use disorder managed with buprenorphine, housing instability, and hypothyroidism, presented with subacute back pain and impaired ambulation following a mechanical fall. The patient experienced persistent back pain, numbness, ambulatory difficulties, and intermittent urinary incontinence. An evaluation revealed pain-limited 4/5 motor strength bilaterally in lower extremity muscles, intact sensation, and preserved perianal sensation with normal rectal tone. Imaging confirmed a displaced U-type sacral fracture with 37.1 degrees of focal kyphosis and no ongoing nerve root compression. Given the focal kyphosis and associated complications, a multidisciplinary team with orthopaedic trauma and spine expertise recommended percutaneous reduction spinopelvic fixation to achieve reduction and stabilization. The patient's significant risk factors, including active drug use and housing instability, raised concerns with a traditional open approach. A percutaneous approach using an external fixator aided reduction, followed by transiliac trans-sacral screw placement and S1-pelvis fixation, was chosen. This technique achieved the desired reduction in sacral kyphosis, improving spinopelvic alignment and reducing postoperative soft tissue complications. Postoperative imaging showed appropriately placed hardware and a 20-degree reduction in sacral kyphosis.

Conclusions

This case highlights the successful management of a displaced U-type sacral fracture with focal kyphosis using a percutaneous spinopelvic external fixator-based reduction technique. A minimally invasive approach can achieve significant reduction in deformity while minimizing soft tissue complications, making it viable for patients with complex medical histories. The clinical impact includes improved postoperative recovery and reduced risk of long-term disability. This case underscores the importance of individualized surgical planning and the potential benefits of percutaneous techniques in managing complex sacral fractures.

Traumatic lumbosacral instability: part 2-indications and techniques for surgical management

Traumatic lumbosacral instability (TLSI) refers to a traumatic disruption of the axial skeleton at the level of the lumbosacral motion segment and/or sacrum, resulting in mechanical separation of the caudal spinal column from the posterior pelvic ring. Managing TLSI and its four underlying conditions poses unique challenges among spinal and pelvic injuries. This second part of a two-part series focuses on treatment strategies and decision making in TLSI, with an emphasis on surgical stabilization techniques. The primary objectives of this article are to: (1) elucidate factors influencing clinical decision-making, (2) synthesize current treatment options for the injury patterns underlying TLSI, and (3) briefly outline expected outcomes and complications.

Radiology resident competency in orthopedic trauma detection in simulated on-call scenarios

PURPOSE

To evaluate radiology residents' ability to accurately identify three specific types of orthopedic trauma using radiographic imaging within a simulated on-call environment.

METHODS

We utilized the Wisdom in Diagnostic Imaging Emergent/Critical Care Radiology Simulation (WIDI SIM) to assess residents' preparedness for independent radiology call. The simulation included 65 cases, with three focusing on orthopedic trauma: sacral ala, femoral neck, and pediatric tibial/Toddler's fractures. Faculty graded residents' responses using a standardized 10-point rubric and categorized errors as observational (failing to identify key findings) or interpretive (incorrect conclusions despite correct identification of findings).

RESULTS

321 residents evaluated sacral ala fracture radiographs and received an average score of 1.29/10, with 8.71 points lost to observational errors. Only 6% produced effective reports (scores ≥ 7), while 80% made critical errors (scores < 2). For femoral neck fracture CT images (n = 316 residents), the average score was 2.48/10, with 6.71 points lost to observational errors. 25% produced effective reports, and 66% made critical errors. Pediatric tibial/Toddler's fracture radiographs (n = 197 residents) yielded an average score of 2.94/10, with 6.60 points lost to observational errors. 29% generated effective reports, while 71% made critical errors.

CONCLUSION

Radiology residents demonstrated significant difficulty in identifying these orthopedic trauma cases, with errors primarily attributed to observational deficiencies. These findings suggest a need for targeted educational interventions in radiology residency programs to improve the identification of these fractures.

Radiosurgery Society Case-Based Guide to Stereotactic Body Radiation Therapy for Challenging Cases of Spinal Metastases

PURPOSE

Spinal stereotactic body radiation therapy (SBRT) has become the standard of care in management of patients with limited sites of metastatic disease, radioresistant histologies, painful vertebral metastases with long life expectancy and cases of reirradiation. Our case-based guidelines aim to assist radiation oncologists in the appropriate utilization of SBRT for common, yet challenging, cases of spinal metastases.

METHODS AND MATERIALS

Cases were selected to include scenarios of large volume sacral disease with nerve entrapment, medically inoperable disease abutting the thecal sac, and local failure after prior SBRT. Relevant literature was reviewed, and areas requiring further investigation were discussed to offer a framework for evidence-based clinical practice.

RESULTS

Spinal SBRT can be effectively delivered in challenging cases following multidisciplinary discussion by using a methodical approach to patient selection, appropriate dose selection, and adherence to evidence-based dose constraints.

CONCLUSIONS

The Radiosurgery Society's case-based practice review offers guidance to practicing physicians treating technically challenging SBRT candidate patients with spinal metastases.

Reduction and Fixation of Bilateral Sacroiliac Fracture-Dislocations with Pelvic Brim Screws and Robotic-Assisted Lumbopelvic Fixation: A Case Report

CASE

A 53-year-old man with bilateral sacroiliac (SI) fracture-dislocations underwent open reduction internal fixation with subsequent loss of fixation. Revision involved the placement of pelvic brim screws and robotic-assisted lumbopelvic fixation, resulting in minimal blood loss and soft-tissue injury. At 3-month follow-up, the patient had healed and was advanced to full weight-bearing status.

CONCLUSION

Percutaneous SI screws and robotic-assisted spinopelvic fixation effectively managed bilateral SI fracture-dislocations, despite narrow osseous corridors, providing adequate stabilization while minimizing complications. The combination of these 2 techniques helped overcome anatomical limitations and reduced technical challenges, leading to a successful short-term outcome.

Treatment Outcomes of Lower Urinary Tract Symptoms due to Fragility Sacral Fractures: A Review of Eight Patients and Literature

BACKGROUND

Sacral fractures can cause lower urinary tract symptoms (LUTS) due to damage to the cauda equina. While several studies have reported on sacral fractures due to high-energy trauma, those due to fragility fractures have only been reported in case reports and their clinical differences are not well known. This study aimed to investigate the clinical characteristics of LUTS caused by fragility sacral fractures and propose a novel treatment strategy.

METHODS

This study is retrospective, uncontrolled, clinical case series. The inclusion criteria were sole sacral fractures due to low-energy trauma and appearance of LUTS after injury. Patients with additional spinal fractures or combined abdominal or pelvic organ injuries that could cause LUTS were excluded. Improvement in LUTS, period from onset to improvement, and imaging findings were recorded.

RESULTS

Eight patients met the inclusion criteria (4 surgical and 4 conservative treatment cases). Six patients showed improvement in LUTS. In surgical cases, the mean period from onset of LUTS to surgery and from onset of LUTS to improvement was 14.5 and 21.5 days, respectively. Intraoperative rupture or laceration of the dural sac was not observed. In 2 conservatively improved cases, the period from onset to improvement of LUTS was 14 and 17 days.

CONCLUSIONS

LUTS can improve even with conservative treatment and should be utilized as the primary choice. LUTS caused by severe sacral canal deformity and stenosis can be reversible, and the decision to perform surgical treatment is still timely if LUTS do not improve with conservative treatment for several weeks.

[Translated article] Spinopelvic dissociation: Current concepts

INTRODUCTION

Spinopelvic dissociation is an uncommon injury, but, at the same time, very serious, since it can associate important complications with high morbidity and mortality. Its low frequency means that the experience of the specialists who have to deal with it is often very limited.

OBJECTIVE

To analyze the treatment indications based in classifications and surgery techniques.

METHOD

A search for scientific articles from high-impact journals was performed through international databases, such as Pubmed, Cochrane Library, Scopus, Science Direct and OVID.

CONCLUSIONS

The management of the injury we are analyzing represents a challenge. The diagnosis is carried out through a meticulous anamnesis and physical examination, supported by imaging tests, where tomography acquires special relevance. The treatment is fundamentally surgical, reserved the conservative option for a few cases. Triangular fixation is nowadays considered the treatment of choice.

Spinopelvic dissociation: Current concepts

INTRODUCTION

Spinopelvic dissociation is an uncommon injury, but, at the same time, very serious, since it can associate important complications with high morbidity and mortality. Its low frequency means that the experience of the specialists who have to deal with it is often very limited.

OBJECTIVE

To analyze the treatment indications based in classifications and surgery techniques.

METHOD

A search for scientific articles from high-impact journals was performed through international databases, such as Pubmed, Cochrane Library, Scopus, Science Direct and OVID.

CONCLUSIONS

The management of the injury we are analyzing represents a challenge. The diagnosis is carried out through a meticulous anamnesis and physical examination, supported by imaging tests, where tomography acquires special relevance. The treatment is fundamentally surgical, reserved the conservative option for a few cases. Triangular fixation is nowadays considered the treatment of choice.

Posterior pelvic ring injuries, lumbosacral junction instabilities and stabilization techniques for spinopelvic dissociation: a narrative review

INTRODUCTION

From transiliac Harrington rods to minimally invasive (MIS) percutaneous 3D-navigated transsacral-transiliac screw (TTS) fixation, concepts of fixation methods in pelvic injuries with spinopelvic dissociation (SPD) are steadily redefined. This narrative review examines the literature of recent years regarding surgical treatment options and trends in SPD, outlining risks and benefits of each treatment option and addressing biomechanical aspects of sacral injuries and common classification systems.

MATERIALS AND METHODS

A literature search on the search across relevant online databases was conducted. As a scale for quality assessment, the SANRA-scoring system was taken into account.

RESULTS

Sacral Isler type 1 injuries of the LPJ in U- and H-type fractures are frequently treated with stand-alone TTS. Fractures with higher instability (Isler types 2 and 3) require unilateral or bilateral LPF, subject to side involvement, as a buttressing construct, or triangular fixation as additional compression and neutralization, determined by fracture radiation. A more comprehensive classification from which to derive stabilization options is provided by the 2023 301SPD classification. MIS techniques are on the rise and offer shorter OR time, less blood loss, fewer infections, and fewer wound complications. It is advisable to implement MIS techniques as much as possible, as long as decompression is not required and closed fracture reduction succeeds satisfactorily.

CONCLUSION

SPD is characteristic of severe injuries, mostly in polytraumatized patients. The complication rates are decreasing due to the increasing adaptation of MIS techniques.

Operative versus conservative treatment in pelvic ring fractures with sacral involvement

BACKGROUND

To evaluate the performance in activities of daily living (ADL), level of pain, mortality and rate of complications in patients with a pelvic ring fracture with sacral involvement who were treated conservatively compared to a surgically treated patient collective using percutaneous iliosacral screw fixation.

HYPOTHESIS

Conservative treatment does not result in inferior clinical outcome compared to operative treatment.

PATIENTS AND METHODS

A retrospective study of 112 conservatively (n=46) or operatively (n=66) treated patients with an isolated posterior or a combined posterior and anterior pelvic ring fracture was performed. The analysis included: age, sex, mechanism of injury, fracture type according to AO/OTA classification, energy of trauma sustained (no-, low-, high-energy trauma), type of treatment (operative or conservative), complications as well as duration of in-hospital stay. To assess clinical and activity outcome, the visual analog scale for pain (VAS), Barthel Scale, American Society of Anaesthesiologists (ASA) scores as well as mortality were assessed. The mean follow-up was 29.3±14.6 months. Furthermore, a geriatric subgroup (n=68, age≥60, low-energy trauma only) was analyzed.

RESULTS

The majority of the patients were female (79%) and suffered from low-energy trauma (n=64, 58%). There were no significant differences in the operative and the conservative groups and subgroups concerning VAS, Barthel scores and ASA scores. The survival analyses showed a significantly lower survival rate in the conservative group (41.8±3.6 months) compared to the operative group (55.9±2 months, p=0.002). Similar findings were encountered in the geriatric subgroup analysis.

CONCLUSION

This study demonstrates equivalent clinical outcome in conservatively and surgically treated patients using a percutaneous iliosacral screw fixation at a mid-term follow-up. However, operatively treated patients showed decreased mortality. This needs to be carefully considered in clinical decision-making but must be further explored using a prospective randomized study approach.

LEVEL OF EVIDENCE

III.

Effective Management of Sacral Stress Fractures in Gastric Cancer: Iliosacral Screw Fixation Following a Type 3 Hemipelvectomy

Metastatic pelvic tumors pose a significant challenge in oncologic orthopedics due to their complex management and the high potential for postoperative complications. This case study discusses a 75-year-old male with a sacral stress fracture following a type 3 internal hemipelvectomy for a metastatic lesion from gastric cancer in the left pubic bone. Initial conservative treatments failed to yield satisfactory improvement, leading to surgical intervention. Open reduction and internal fixation with an iliosacral screw, despite complications, significantly alleviated pain and improved mobility. This case underscores the difficulty in diagnosing sacral stress fractures versus metastatic lesions and highlights the effectiveness of iliosacral screw fixation in managing postoperative sacral stress fractures. It emphasizes the procedure's role in providing early pain relief and enhancing daily activity levels. Additionally, it points out the importance of addressing altered bone metabolism in the postoperative care of patients with metastatic pelvic tumors. This contributes to the literature by stressing the incidence of sacral stress fractures as a critical, though often overlooked, complication and demonstrating the benefits of iliosacral screw fixation in such scenarios for better recovery and quality of life.

L4 fixation is not necessary in L5-Iliac spinopelvic fixation after trauma, but coadjutant transilio-transsacral fixation is

INTRODUCTION

Spinopelvic dissociation (SPD) is a severe injury characterized by a discontinuity between the spine and the bony pelvis consisting of a bilateral longitudinal sacral fracture, most of the times through sacral neuroforamen, and a horizontal fracture, usually through the S1 or S2 body. The introduction of the concept of triangular osteosynthesis has shown to be an advance in the stability of spinopelvic fixation (SPF). However, a controversy exists as to whether the spinal fixation should reach up to L4 and, if so, it should be combined with transiliac-transsacral screws (TTS).

OBJECTIVE

The purpose of this study is to compare the biomechanical behavior in the laboratory of four different osteosynthesis constructs for SPD, including spinopelvic fixation of L5 versus L4 and L5; along with or without TTS in both cases.

MATERIAL AND METHODS

By means of a formerly described method by the authors, an unstable standardized H-type sacral fracture in twenty synthetic replicas of a male pelvis articulated to the lumbar spine, L1 to sacrum, (Model: 1300, SawbonesTM; Pacific Research Laboratories, Vashon, WA, USA), instrumented with four different techniques, were mechanically tested. We made 4 different constructs in 5 specimen samples for each construct. Groups: Group 1. Instrumentation of the L5-Iliac bones with TTS. Group 2. Instrumentation of the L4-L5-Iliac bones with TTS. Group 3. Instrumentation of L5-Iliac bones without TTS. Group 4: Instrumentation of L4-L5-Iliac bones without TTS.

RESULTS AND CONCLUSIONS

According to our results, it can be concluded that in SPD, better stability is obtained when proximal fixation is only up to L5, without including L4 (alternative hypothesis), the addition of transiliac-transsacral fixations is essential.

Sacroplasty for Sacral Insufficiency Fractures: Narrative Literature Review on Patient Selection, Technical Approaches, and Outcomes

Sacral insufficiency fractures commonly affect elderly women with osteoporosis and can cause debilitating lower back pain. First line management is often with conservative measures such as early mobilization, multimodal pain management, and osteoporosis management. If non-operative management fails, sacroplasty is a minimally invasive intervention that may be pursued. Candidates for sacroplasty are patients with persistent pain, inability to tolerate immobilization, or patients with low bone mineral density. Before undergoing sacroplasty, patients' bone health should be optimized with pharmacotherapy. Anabolic agents prior to or in conjunction with sacroplasty have been shown to improve patient outcomes. Sacroplasty can be safely performed through a number of techniques: short-axis, long-axis, coaxial, transiliac, interpedicular, and balloon-assisted. The procedure has been demonstrated to rapidly and durably reduce pain and improve mobility, with little risk of complications. This article aims to provide a narrative literature review of sacroplasty including, patient selection and optimization, the various technical approaches, and short and long-term outcomes.

Triangular Osteosynthesis as a Surgical Treatment Option for Unstable Sacral Fracture Fixation with Sacroiliac Dislocation: A Case Report

Introduction

Sacral fractures, which can occur in young individuals following road traffic accidents or falls from a height, as well as in elderly individuals with osteoporosis after minor trauma, are considered a diverse type of fracture. The incidence of non-osteoporotic sacral fractures is estimated to be 2.1/100,000 people, whereas osteoporotic fractures are estimated to affect 1-5% of elderly individuals at risk. Triangular osteosynthesis is a relatively new fixation technique used as a surgical treatment for unstable sacral fractures. It combines transverse fixation with lumbo-pelvis distraction osteosynthesis, providing stability in different planes. The subcategory of triangular osteosynthesis encompasses spinopelvic fixation, which involves the fusion of transverse sacral alar fracture fixation (such as iliosacral screw/s and sacral plate) and unilateral lumbopelvic fixation from the pedicle of L5 to the ipsilateral posterior ilium. The utilization of this technique provides a mechanically advanced approach for stabilizing unstable sacral alar fractures with vertical shear. Once the pelvic ring injury has been reduced, lumbopelvic fixation can assist in preventing the recurrence of vertical displacement in the unstable hemipelvis.

Case Report

The patient, a 29-year-old male, experienced a road traffic accident resulting from a collision involving a motorcycle. As a result of the incident, he suffered from an unstable lateral compression type 1 pelvic ring injury, accompanied by an ipsilateral sacroiliac dislocation and a vertical sacral fracture on the opposite side. Computed tomography imaging revealed a right sacroiliac dissociation, a left sacral fracture classified as AO type B1, as well as fractures in both the superior and inferior pubic rami. The pelvic ring of the patient was subjected to closed reduction and percutaneous fixation, accompanied by minimally invasive spinopelvic fixation. The surgical procedure was performed in a single session, involving the reduction and fixation of the right sacroiliac dissociation, followed by lumbopelvic fixation while in the prone position. After a 1-month follow-up, the patient demonstrated the ability to walk without experiencing pain, and the X-ray revealed a stable spinopelvic and sacroiliac fixation.

Conclusion

The utilization of triangular osteosynthesis fixation provides a reliable form of fixation that enables the patient to bear complete weight at an early stage of 6 weeks while also preventing any reduction loss in vertical shear transforaminal sacral fractures.

Patient-specific bone material modelling can improve the predicted biomechanical outcomes of sacral fracture fixation techniques: A comparative finite element study

OBJECTIVE

To evaluate and compare the biomechanical efficacy of six iliosacral screw fixation techniques for treating unilateral AO Type B2 (Denis Type II) sacral fractures using literature-based and QCT-based bone material properties in finite element (FE) models.

METHODS

Two FE models of the intact pelvis were constructed: the literature-based model (LBM) with bone material properties taken from the literature, and the patient-specific model (PSM) with QCT-derived bone material properties. Unilateral transforaminal sacral fracture was modelled to assess different fixation techniques: iliosacral screw (ISS) at the first sacral vertebra (S1) (ISS1), ISS at the second sacral vertebra (S2) (ISS2), ISS at S1 and S2 (ISS12), transverse iliosacral screws (TISS) at S1 (TISS1), TISS at S2 (TISS2), and TISS at S1 and S2 (TISS12). A 600 N vertical load with both acetabula fixed was applied. Vertical stiffness (VS), relative interfragmentary displacement (RID), and the von Mises stress values in the screws and fracture interface were analysed.

RESULTS

The lowest and highest normalised VS was given by ISS1 and TISS12 techniques for LBM and PSM, with 137 % and 149 %, and 375 % and 472 %, respectively. In comparison with the LBM, the patient-specific bone modelling increased the maximum screw stress values by 19.3, 16.3, 27.8, 2.3, 24.4 and 7.8 % for ISS1, ISS2, ISS12, TISS1, TISS2 and TISS12, respectively. The maximum RID values were between 0.10 mm and 0.47 mm for all fixation techniques in both models. The maximum von Mises stress results on the fracture interface show a substantial difference between the two models, as PSM (mean ± SD of 15.76 ± 8.26 MPa) gave lower stress values for all fixation techniques than LBM (mean ± SD of 28.95 ± 6.91 MPa).

CONCLUSION

The differences in stress distribution underline the importance of considering locally defined bone material properties when investigating internal mechanical parameters. Based on the results, all techniques demonstrated clinically sufficient stability, with TISS12 being superior from a biomechanical standpoint. Both LBM and PSM models indicated a consistent trend in ranking the fixation techniques based on stability. However, long-term clinical trials are recommended to confirm the findings of the study.

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.

Treatment of Unstable Sacral Fractures with Robotically-aided Minimally Invasive Triangular Fixation

OBJECTIVE

The treatment of unstable sacral fractures is huge challenge to surgeons. Robotically-aided minimally invasive triangular fixation (RoboTFX) is the most advanced technique up to now. This study is to evaluate the clinical outcomes of unstable sacral fractures treated with RoboTFX.

METHODS

From March 2017 to October 2021, 48 consecutive patients with unstable sacral fractures were included in the study. All patients received surgical treatment with triangular fixation (TFX). Patients were divided into four groups according to the number of fractures (uni- or bilateral) and surgical method employed (RoboTFX or traditional open TFX). Between these four groups, clinical data on operation time, intraoperative bleeding, intraoperative fluoroscopy time, infection rate, fracture healing rates, insertion accuracy, Majeed pelvic outcome score, Mears' criterion, and Gibbons score were compared. Quantitative data were expressed as mean ± standard deviation and compared using Student's t-test. Categorical variable were compared using the Pearson's χ2 test.

RESULTS

Comparing unilateral RoboTFX versus open TFX, neither fracture healing rate, infection rate, Majeed pelvic outcome score, Mears' radiological evaluation criterion, nor Gibbons score of the two groups were statistically significantly different (p > 0.05). However, operation time, intraoperative bleeding, intraoperative fluoroscopy time, and insertion accuracy in the RoboTFX group were all significantly better than those of the traditional open group (p < 0.05). Likewise, operation time, intraoperative bleeding, intraoperative fluoroscopy time, and accuracy of fixation insertion of the bilateral RoboTFX group were significantly better than those of the bilateral open group (p < 0.05). Meanwhile infection rate, fracture healing rate, Majeed score, Mears' criterion, and Gibbons score of two groups were not significantly different (p > 0.05).

CONCLUSION

RoboTFX has the advantages of less operation time, less intraoperative bleeding and fluoroscopy, more accurate fixation insertion, and a higher healing rate compared to traditional open methods in the treatment of unstable sacral fractures. However, RoboTFX requires a few critical considerations, and the indications of its operation should be strictly evaluated.

A Case Report of U-Type Sacral Fracture After Chiropractic Adjustment

CASE

A U-type sacral fracture, or spinopelvic dissociation, resulting from chiropractic manipulation has not been described in the medical literature. This report presents the case of a 74-year-old male patient who sustained a U-type sacral fracture after drop-table chiropractic manipulation.

CONCLUSION

Our case demonstrates that chiropractic manipulative therapy involving the commonly used drop-table can cause severe injury. The patient's course was complicated by a delay in diagnosis and a prolonged hospital stay. Orthopaedic surgeons should have a high degree of suspicion for spinopelvic dissociation in the setting of bilateral sacral fractures. One year after injury, with conservative management, the patient returned to baseline function with mild residual neuropathy.

Consensus for management of sacral fractures: from the diagnosis to the treatment, with a focus on the role of decompression in sacral fractures

BACKGROUND

There is no evidence in the current literature about the best treatment option in sacral fracture with or without neurological impairment.

MATERIALS AND METHODS

The Italian Pelvic Trauma Association (A.I.P.) decided to organize a consensus to define the best treatment for traumatic and insufficiency fractures according to neurological impairment.

RESULTS

Consensus has been reached for the following statements: When complete neurological examination cannot be performed, pelvic X-rays, CT scan, hip and pelvis MRI, lumbosacral MRI, and lower extremities evoked potentials are useful. Lower extremities EMG should not be used in an acute setting; a patient with cauda equina syndrome associated with a sacral fracture represents an absolute indication for sacral reduction and the correct timing for reduction is "as early as possible". An isolated and incomplete radicular neurological deficit of the lower limbs does not represent an indication for laminectomy after reduction in the case of a displaced sacral fracture in a high-energy trauma, while a worsening and progressive radicular neurological deficit represents an indication. In the case of a displaced sacral fracture and neurological deficit with imaging showing no evidence of nerve root compression, a laminectomy after reduction is not indicated. In a patient who was not initially investigated from a neurological point of view, if a clinical investigation conducted after 72 h identifies a neurological deficit in the presence of a displaced sacral fracture with nerve compression on MRI, a laminectomy after reduction may be indicated. In the case of an indication to perform a sacral decompression, a first attempt with closed reduction through external manoeuvres is not mandatory. Transcondylar traction does not represent a valid method for performing a closed decompression. Following a sacral decompression, a sacral fixation (e.g. sacroiliac screw, triangular osteosynthesis, lumbopelvic fixation) should be performed. An isolated and complete radicular neurological deficit of the lower limbs represents an indication for laminectomy after reduction in the case of a displaced sacral fracture in a low-energy trauma associated with imaging suggestive of root compression. An isolated and incomplete radicular neurological deficit of the lower limbs does not represent an absolute indication. A worsening and progressive radicular neurological deficit of the lower limbs represents an indication for laminectomy after reduction in the case of a displaced sacral fracture in a low-energy trauma associated with imaging suggestive of root compression. In the case of a displaced sacral fracture and neurological deficit in a low-energy trauma, sacral decompression followed by surgical fixation is indicated.

CONCLUSIONS

This consensus collects expert opinion about this topic and may guide the surgeon in choosing the best treatment for these patients.

LEVEL OF EVIDENCE

IV.

TRIAL REGISTRATION

not applicable (consensus paper).

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.

Bony Sacral Volume after Sacro-Iliac Screw Fixation of Pelvic Fractures Is Dependent on Reduction of the Anterior Pelvic Ring

Pelvic ring injuries are uncommon but serious injuries. Percutaneous sacro-iliac screw fixation (SSF) is the standard treatment for posterior stabilization of pelvic fractures. Compression forces of the SSF might cause deformity of the sacrum and the pelvic ring. The aim of this radio-volumetric study is to evaluate the morphometry of the sacrum and pelvic ring in SSF for posterior pelvic fractures. (1) Methods: We conducted a radio-volumetric study measuring the bony sacral volume before and after SSF for a pelvic fracture based on a three-dimensional reconstruction of the pre- and postoperative computed tomography scan of 19 patients with a C-type pelvic fracture. In addition to the bony sacral volume, we assessed the pelvic deformity and the load bearing axis. We compared the results of patients without anterior stabilization (Group A) to patients who had additional ORIF of the anterior pelvic ring. (2) Results: Median age of the patients was 41.2 years (±17.8). All patients received percutaneous SSF with partially threaded 7.3 mm screws. The sacral volume decreased from 202.9 to 194.3 cm3 in group A (non-operative treatment anterior, n = 10) and an increase of sacral volume from 229.8 to 250.4 cm3 in group B (anterior ORIF; n = 9). Evaluation of the pelvic deformity also reflected this trend by a decrease of the ipsilateral load-bearing angle in group A (37.0° to 36.4°) and an increase of this angle in group B (36.3 to 39.9°). (3) Conclusions: Bony sacral volume and pelvic deformity after sacro-iliac screw fixation in pelvic fractures depend on treatment of the anterior pelvic ring. Reduction and fixation of the anterior fracture shows an increase of the bony sacral volume and the load bearing angle leading to a closer to normal reconstruction of the pelvic anatomy.

Minimally invasive stabilization of posterior pelvic ring injuries through transiliac internal fixator versus Iliosacral screw: A prospective comparative cohort study

INTRODUCTION

Longitudinal sacral fractures are usually a matter of controversy regarding decision-making for reduction, fixation, and approach. Percutaneous and minimally invasive techniques present perioperative difficulties, but with fewer postoperative complications compared to open techniques. The objective of this study was to compare the functional as well as radiological outcomes of the Transiliac Internal fixator (TIFI) versus Iliosacral screw (ISS) fixation of sacral fractures applied percutaneously in a minimally invasive technique.

METHODS

A Prospective comparative cohort study was conducted in a level 1 trauma center in a university hospital. The study included 42 patients with complete sacral fractures, 21 patients have been allocated to each group (TIFI group & ISS group). The clinical, functional, as well as radiological data, were collected and analyzed for the 2 groups.

RESULTS

The mean age was 32 (18 -54 years), and the mean follow-up was 14 (12 -20 months). There was a statistically significant difference in favor of the TIFI group regarding a shorter operative time (P = 0.04) as well as less fluoroscopy time (P = 0.01) whereas there was less blood loss in the ISS group (P = 0.01). Both the mean Matta's radiological score, the mean Majeed score as well as the pelvic outcome score were comparable between the 2 groups with no statistically significant difference.

CONCLUSION

This study suggests that both TIFI and ISS through a minimally invasive technique represent valid methods for sacral fracture fixation with a shorter operative time, less radiation exposure in TIFI and less blood loss in the ISS. However, the functional, as well as radiological outcomes, were comparable between the 2 groups.

A systematic review regarding clinical characteristics, complications, and outcomes of surgical and non-surgical patients with fragility fracture of the pelvis

We conducted this systematic review to clarify the clinical characteristics, complications, and outcomes of surgical and non-surgical patients with fragility fracture of the pelvis (FFP). We searched PubMed, Google Scholar, Cochrane Library, Web of Science, and MEDLINE for English language articles on FFP. We calculated pooled odds ratios (ORs) or mean differences (MDs) of surgical patients in comparison to non-surgical patients for clinical characteristics (Rommens FFP classification, age, sex, dementia, osteoporosis, diabetes mellitus, pulmonary disease, cardiovascular disease, and malignancy), complications (pneumonia, urinary tract infection, cardiac event, thrombosis, pulmonary embolism, pressure ulcer, multiple organ failure, anemia caused by surgical bleeding, and surgical site infection), and outcomes (hospital mortality and one-year mortality). Five studies involving 1,090 patients with FFP (surgical patients, n = 432; non-surgical patients, n = 658) were included. FFP type III and IV (OR = 8.44; 95% confidence interval [CI] 5.99 to 11.88; p<0.00001), a younger age (MD = -3.29; 95% CI -3.83 to -2.75; p<0.00001), the absence of dementia (OR = 0.36; 95% CI 0.23 to 0.57; p<0.0001), and the presence of osteoporosis (OR = 1.74; 95% CI 1.29 to 2.35; p = 0.0003) were significantly associated with the surgical patients. Urinary tract infection (OR = 2.06; 95% CI 1.37 to 3.10; p = 0.0005), anemia caused by surgical bleeding (OR = 4.55; 95% CI 1.95 to 10.62; p = 0.0005), and surgical site infection (OR = 16.74; 95% CI 3.05 to 91.87; p = 0.001) were significantly associated with the surgical patients. There were no significant differences in the outcomes between the surgical and non-surgical patients. Our findings may help to further understand the treatment strategy for FFP and improve clinical outcomes.

Does minimally invasive percutaneous transilial internal fixator became an effective option for sacral fractures? A prospective study with novel implantation technique

AIM

To assess radiological and functional outcomes of transilial internal fixator (TIFI) for treatment of sacral complete transforaminal fractures with a novel implantation technique that decrease wound irritation problems in addition to facilitating easy application of reduction methods beside showing the best entry points, screw trajectories and angles.

METHODS

A Prospective case series from 2019 to 2021 was conducted at university hospital including 72 patients with Denis type 2 sacral fractures. The operative and fluoroscopy time, reduction, implantation techniques, postoperative radiological and functional data were collected and evaluated with minimum follow-up of 12 months.

RESULTS

The mean initial fracture displacement was 4.42 mm while mean postoperative maximum residual fracture displacement was 2.8 mm, Radiological outcome assessed using Matta's grading at the final follow-up visit with 63 cases scored as Excellent,7 cases as Good, 2 cases as fair. Functional outcome using Majeed scoring shows 64 cases of Excellent grading and 8 cases were Good. Short operative and fluoroscopy time, easy reduction techniques, few skin problems were recorded.

CONCLUSION

TIFI through a minimally invasive technique represents a valid method for dealing with transforaminal sacral fractures. TIFI provides a rigid fixation for posterior ring injuries with few risks regarding iatrogenic nerve injury, avoiding different variations of upper sacral osseous anatomy or sacral dysmorphism. In addition, there is no necessity for high quality fluoroscopy for visualization of sacral foramina intraoperatively, decreasing risk of radiation exposure, unlike other methods of fixation as iliosacral screws. Our novel modification for implantation technique provides few risks for postoperative and wound complications.

Evolution of the AO Spine Sacral and Pelvic Classification System: a systematic review

OBJECTIVE

The purpose of this study was to describe the genesis of the AO Spine Sacral and Pelvic Classification System in the context of historical sacral and pelvic grading systems.

METHODS

A systematic search of MEDLINE, EMBASE, Google Scholar, and Cochrane databases was performed consistent with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to identify all existing sacral and pelvic fracture classification systems.

RESULTS

A total of 49 articles were included in this review, comprising 23 pelvic classification systems and 17 sacral grading schemes. The AO Spine Sacral and Pelvic Classification System represents both the evolutionary product of these historical systems and a reinvention of classic concepts in 5 ways. First, the classification introduces fracture types in a graduated order of biomechanical stability while also taking into consideration the neurological status of patients. Second, the traditional belief that Denis central zone III fractures have the highest rate of neurological deficit is not supported because this subgroup often includes a broad spectrum of injuries ranging from a benign sagittally oriented undisplaced fracture to an unstable "U-type" fracture. Third, the 1990 Isler lumbosacral system is adopted in its original format to divide injuries based on their likelihood of affecting posterior pelvic or spinopelvic stability. Fourth, new discrete fracture subtypes are introduced and the importance of bilateral injuries is acknowledged. Last, this is the first integrated sacral and pelvic classification to date.

CONCLUSIONS

The AO Spine Sacral and Pelvic Classification is a universally applicable system that redefines and reorders historical fracture morphologies into a rational hierarchy. This is the first classification to simultaneously address the biomechanical stability of the posterior pelvic complex and spinopelvic stability, while also taking into consideration neurological status. Further high-quality controlled trials are required prior to the inclusion of this novel classification within a validated scoring system to guide the management of sacral and pelvic injuries.

What Are the Key Factors of Functional Outcomes in Patients with Spinopelvic Dissociation Treated with Triangular Osteosynthesis?

For patients with spinopelvic dissociation (SPD), triangular osteosynthesis is the current method for the fixation of the posterior pelvis. This study aimed to assess the recovery process and radiographic parameters associated with the functional outcomes in patients with SPD treated by triangular osteosynthesis. We collected data from 23 patients with SPD. To investigate the key aspect regarding the functional outcomes of these patients, we measured pre- and post-operative parameters, and a statistical analysis adjusted for age, gender, and time windows was used. The radiographic displacement measurement in the pre-operative period showed that the EQ-5D-5L increased by 2.141 per outlet ratio unit. The EQ-5D-5L increased by 1.359 per inlet ratio unit and 1.804 per outlet ratio during the postoperative period. The EQ-VAS increased significantly only with the inlet ratio in the postoperative period (1.270 per inlet ratio). A vertical reduction in SPD during the surgery can achieve more satisfactory outcomes than a horizontal anatomical reduction, in which the horizontal displacement causes inferior functional outcomes.

The "Eiffel Tower" technique: novel long-axis sacroplasty under electromagnetic navigation assistance; feasibility and descriptive study

OBJECTIVES

To describe a novel long-axis multimodal navigation assisted technique - the so-called Eiffel Tower technique - aimed at integrating recent technological improvements for the routine treatment of sacral insufficiency fractures.

MATERIALS AND METHODS

The long-axis approach described in the present study aimed at consolidating the sacral bone according to biomechanical considerations. The purpose was (i) to cement vertically the sacral alae all along and within the lateral fracture lines, resembling the pillars of a tower, and (ii) to reinforce cranially with a horizontal S1 landing zone (or dense central bone) resembling the first level of the tower. An electromagnetic navigation system was used in combination with CT and fluoroscopic guidance to overtop extreme angulation challenges. All patients treated between January 2019 and October 2021 in a single tertiary center were retrospectively reviewed.

RESULTS

A description of the technique is provided. Twelve female patients (median age: 80 years [range: 32 to 94]) were treated for sacral insufficiency fractures with the "Eiffel Tower" technique. The median treatment delay was 8 weeks (range: 3 to 20) and the initial median pain assessed by the visual analogue scale was 7 (range: 6 to 8). Pain was successfully relieved (visual analogue score < 3) for 9 patients (75%) and persisted for 2 patients (17%). One patient was lost during the follow-up. No complication was noted.

CONCLUSION

The "Eiffel Tower" multimodal cementoplasty integrates recent technological developments, in particular electromagnetic navigation, with the purpose of reconstructing the biomechanical chain of the sacral bone.

KEY POINTS

• Sacral insufficiency fractures are common and can be efficiently treated with percutaneous sacroplasty. • The long axis sacroplasty approach can be challenging given both the shape of the sacral bone and the angulation to reach the target lesion. • The "Eiffel Tower" technique is a novel approach using electromagnetic navigation to expand the concept of the long axis route, adding a horizontal S1 landing zone.

Imaging, post-processing and navigation: Surgical applications in pelvic fracture treatment

Technical advancements of the past decade have led to massive improvements regarding imaging and visualization in trauma care. Digital imaging technology has fundamentally changed most processes in fracture management. However, the digital revolution in trauma surgery has just begun. Optical tracking navigation is currently the gold standard for positioning of implants for advanced applications in trauma surgery. Digital technology may enable the surgeon to achieve the same level of safety even in non-navigated placement of screws: We developed a new planning tool to transcript a preoperative into a semi-transparent "fluoroscopic like" image that can be identified intraoperatively and used as a map for the safe placement of sacro-iliac screws based on the "vestibule concept". In the future, development of artificial intelligence algorithms may provide features like automated segmentation of bone-fragments and other applications for a systematic fracture analysis to improve the standard of care in trauma surgery. Digital transformation has massive impact on diagnostics and surgical management of pelvic fractures. Improved visualization technology provides a better understanding of the surgical anatomy of the pelvis and may enable the surgeon to achieve greatest safety in percutaneous placement of screws even without using optical tracking navigation tools. The "para-axial fusion technique" is a useful tool to plan fluoroscopic views based on a 3D dataset prior to the surgery.

Lumbo-sacral Junction Instability by Traumatic Sacral Fractures: Isler's Classification Revisited - A Narrative Review

STUDY DESIGN

Narrative review.

OBJECTIVES

Multiple classifications have been proposed for sacral fractures since the last century. While initial classifications focussed on vertical and transverse fractures, the recent fracture classifications encompass all injury patterns. In 1990, Isler classified unilateral vertical sacral fractures based on its potential influence on lumbo-sacral joint (LSJ) stability.

METHODS

We re-visited the original description of Isler's classification of sacral fractures and subsequent studies that have cited it. We will further describe basic LSJ anatomy, evolution of sacral classification systems and the use of Isler's classification system as it relates to LSJ instability and chronic low back pain.

RESULTS

Isler described a subset of unilateral vertical sacral fractures where the fracture line exited medial or through the L5-S1 facet joint, based on radiographic review of 193 sacral fractures (incidence -3.5%). He stated that such a fracture should be recognised as it can impede hemi-pelvis reduction and can result in late LSJ instability. The article has been cited in 106 studies and only a few studies have described the incidence of this variant. Nevertheless, the injury is considered as an indication for surgical fixation.

CONCLUSION

A review of various classifications indicates that sacral fractures have three important bio-mechanical implications, namely, pelvic ring continuity (vertical fractures), spino-pelvic alignment (high transverse fractures) and lumbo-sacral joint integrity (Isler's fractures). Though there is a universal recognition of Isler's fractures and its impact on LSJ integrity, there is a lack of clinical and bio-mechanical evidence regarding the concept of instability caused by a unilateral Isler fracture.

Posterior INFIX for Treating Unilateral Unstable Sacral Fractures

Objective

To evaluate the clinical outcomes of the treatment of unilateral unstable sacral fractures by fixation with the posterior INFIX (posterior pelvic ring screw‐rod internal fxation).

Methods

Data of 60 patients with unilateral unstable sacral fractures who underwent surgery from March 2013 to March 2020 were retrospectively analyzed according to the selection criteria. All patients were associated with anterior pelvic ring injuries, and the operations were performed by the same team of surgeons. According to the different types of internal fixation, the patients were divided into two groups, which both included 30 patients: the posterior INFIX group and iliosacral screw fixation group. The demographic and clinical data of the two patient groups, such as age, sex, sacral fracture types based on the Denis classification, operation time, amount of intraoperative bleeding, intraoperative fluoros copy time, Majeed pelvic score at final follow‐up, and quality of fracture reduction based on Mears and Velyvis's imaging classification criteria were collected by the same researcher and compared statistically.

Results

All patients were continuously followed up for 23.17 ± 3.34 months (range, 12 to 46 months). All sacral fractures healed with an average healing time of 9.3 ± 2.24 months (range, 6 to 18 months). None of the patients had re‐displacement of the fracture or fixation failure. Compared to the iliosacral screw group, the posterior INFIX group patients had more intraoperative bleeding (t = 3.59, P < 0.001), shorter operation time (t = 4.49, P < 0.001), and shorter intraoperative fluoroscopy time (t = 6.26, P < 0.001). There were no statistical differences between the two groups in terms of age, sex, fracture type, Majeed score, and quality of fracture reduction (P > 0.05). In the posterior INFIX group, one patient had a superficial wound infection and one patient complained of discomfort due to a prominent fixation. In the iliosacral screw fixation group, one patient had intraoperative iatrogenic S1 nerve injury and vessel injury. The posterior INFIX fixation was a simpler manipulation with higher safety, shorter time of operation and intraoperative fluoroscopy, and similar clinical outcomes compared to iliosacral screw fixation.

Conclusion

For the treatment of unilateral unstable sacral fractures, the posterior INFIX fixation can be recommended in clinic application.

S2-alar-iliac screw and S1 pedicle screw fixation for the treatment of non-osteoporotic sacral fractures: a finite element study

Background

Five different sacral fracture fixation methods were compared using finite element (FE) analysis to study their biomechanical characteristics.

Methods

Denis type I sacral fractures were created by FE modeling. Five different fixation methods for the posterior pelvic ring were simulated: sacroiliac screw (SIS), lumbopelvic fixation (LPF), transiliac internal fixator (TIFI), S2-alar-iliac (S2AI) screw and S1 pedicle screw fixation (S2AI-S1) and S2AI screw and contralateral S1 pedicle screw fixation (S2AI-CS1). Four different loading methods were implemented in sequence to simulate the force in standing, flexion, right bending and left twisting, respectively. Vertical stiffness, relative displacement and change in relative displacement were recorded and analyzed.

Results

As predicted by the FE model, the vertical stiffness of the five groups in descending order was S2AI-S1, SIS, S2AI-CS1, LPF and TIFI. In terms of relative displacement, groups S2AI-S1 and S2AI-CS1 displayed a lower mean relative displacement, although group S2AI-CS1 exhibited greater displacement in the upper sacrum than group S2AI-S1. Group SIS displayed a moderate mean relative displacement, although the displacement of the upper sacrum was smaller than the corresponding displacement in group S2AI-CS1, while groups LPF and TIFI displayed larger mean relative displacements. Finally, in terms of change in relative displacement, groups TIFI and LPF displayed the greatest fluctuations in their motion, while groups SIS, S2AI-S1 and S2AI-CS1 displayed smaller fluctuations.

Conclusion

Compared with SIS, unilateral LPF and TIFI, group S2AI-S1 displayed the greatest biomechanical stability of the Denis type I sacral fracture FE models. When the S1 pedicle screw insertion point on the affected side is damaged, S2AI-CS1 can be used as an appropriate alternative to S2AI-S1.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13018-021-02805-8.

Surgical Fixation of Sacral Fractures in the Elderly Population: Are There Predictors of Outcome? An Analysis of Return to Ambulation and Residential Living Status

Introduction:

Recent literature suggests that surgical fixation of elderly sacral fractures may reduce time to mobilization and ultimately self-sufficiency. However, it is unclear if predictors of success exist in this subpopulation. The objective of this study was to characterize relative change in ambulation and residential living statuses (pre-injury vs. post-surgery) of elderly patients who received surgical fixation of sacral fractures, as well as determine whether or not demographics and injury characteristics influence these findings.

Methods:

Fifty-four elderly patients (≥60 years old) receiving percutaneous screw fixation of sacral fractures were retrospectively reviewed. All fractures were traumatic in nature; insufficiency fractures were excluded. Patient and surgical demographic data, as well as 1-year mortality status, was reported. Primary study endpoints included relative change in patient ambulation and residential living statuses (pre-injury to post-surgery). Statistical analyses were performed to assess relative change in ambulation/living status from pre-injury to post-surgery and to determine if predictors of outcome existed.

Results:

Of the 54 patients who met inclusion criteria, 4 expired prior to discharge, 2 expired post-discharge, and 4 were lost to follow-up. Of those patients discharged, 95.7% regained some form of ambulation at last follow-up (mean: 22.4 ± 18.9 weeks). Of patients living independent pre-injury, 94.9% would eventually return to independent home living. Neither time-to-surgery, concomitant orthopaedic injury, Charlson Comorbidity Index, or injury mechanism were predictors of final ambulation or residential status (p ≥ 0.07). Mortality at 1-year was 11.1%.

Discussion:

Operative fixation supported a high rate of return to pre-injury ambulation and residential living status. However, there did not appear to be measures predictive of final functional status. Further efforts with larger, prospective cohorts are warranted.