Trans-iliac-sacral-iliac-bar procedure to treat insufficiency fractures of the sacrum

Lumbopelvic Stabilization with Two Methods of Triangular Osteosynthesis: A Biomechanical Study

(1) Background: Pelvic fractures, and particularly instabilities of the dorsal pelvic ring, are becoming increasingly prevalent, particularly in orthogeriatric patients. Spino-pelvic triangular osteosynthesis is an effective approach to achieve sufficient stabilization in vertically unstable fractures. This study compares two types of osteosynthesis: the conventional one and a novel instrumentation where the iliosacral screw is placed through a fenestrated iliac screw. (2) Methods: Sixteen artificial osteoporotic L5+pelvis models with an unstable sacral fracture have been instrumented with either an iliac screw connected with a rod to a L5 pedicle screw and an iliosacral screw (TF) or a fenestrated ilium screw connected with a rod to a L5 pedicle screw and an iliosacral screw passing through the fenestra of the iliac screw (TFS). Biomechanical testing was performed using cyclic loading until failure. (3) Results: Both configurations yielded comparable results with regard to initial stiffness, implant loosening, and cycles to failure. The TFS exhibited markedly higher values for cycles to failure and markedly lower values for loosening. However, due to the characteristics of the artificial bone model, these findings were not significant. (4) Conclusions: The novel triangular fixation systems demonstrated comparable results to the standard triangular osteosynthesis configuration.

Evaluating Treatment Outcomes for Pelvic Insufficiency Fractures: A Systematic Review

Background: Pelvic insufficiency fractures (PIF) are typical in geriatric populations with reduced bone quality, most commonly in elderly postmenopausal women. These fractures are usually caused by low-energy forces over the bones during ordinary life and cause disabling pain. Treatment options range from conservative to operative. The aim of this study is to assess the outcomes of treatments for pelvic insufficiency fractures, determining optimal approaches between surgical intervention and conservative management. Methods: This literature review systematically examines articles focusing on patients with PIF, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, and using PubMed, Medline, and the Cochrane Library database. We took into account only full-text articles in indexed journals with available English abstracts, considering data about patient demographics, surgery, and outcomes. Results: After screening 128 articles, this study reviewed 20 manuscripts involving 1499 patients, mostly elderly females and focusing on sacrum fractures. Common treatments included conservative methods and sacroplasty, with a few complications reported. Osteoporosis was the prevalent comorbidity, and the survival rate post-treatment was high at 92.3%. Mobility outcomes varied, with some patients experiencing significant autonomy loss. The average follow-up period was over 17 months. Conclusions: This study found a cautious approach to surgery (timing of three weeks), which is reserved only for specific patterns, and it leads to increased autonomy and a lower risk of mortality. Due to the lack of pre- and postoperative scores as well as conflicting results, it is imperative to undertake further studies and research to be able to compare the alternative treatments efficiently.

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.

A Systematic Review of Sacral Insufficiency Fractures: Treatment Modalities and Outcomes

Sacral insufficiency fractures can be managed conservatively, by surgical fixation or by sacroplasty. This systematic review compared the outcomes of different treatment modalities to ascertain the best. Studies included in this systematic review were those with sacral insufficiency fracture in elderly patients with some measure of outcomes reported. Fractures due to high-energy trauma or malignancy or in non-elderly patients were excluded. The review was carried out according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. MEDLINE and Embase databases were searched from inception to January 6, 2022, yielding a total of 4299 papers of which 35 were eligible for inclusion. Pain reduction following sacroplasty (Visual Analogue Scale (VAS) difference 5.83, SD 1.14, n = 901) was superior compared with conservative management (VAS difference 3.7, SD 2.71, n = 65) (p <0.0001) and surgical fixation (with screws/rods +/- cement augmentation; VAS difference 4.1, SD 1.106, n = 154) (p< 0.001). There was no significant difference between pain relief following screw fixation and after conservative management (p = 0.1216). Hospital stay duration was shorter following sacroplasty (4.1 days )SD 3.9)) versus fixation (10.3 days (SD 5.59)) (p= 0.0001). Available evidence points to sacroplasty resulting in better pain relief and shorter hospital stay than other treatment options.

Perioperative outcome of minimally invasive stabilisation of bilateral fragility fractures of the sacrum: a comparative study of bisegmental transsacral stabilisation versus spinopelvic fixation

PURPOSE

Pelvic fragility fractures have steadily risen over the past decades. The primary treatment goal is the fastest possible mobilisation. If conservative therapy fails, surgical fixation is a promising approach. This study compares the outcome of bisegmental transsacral stabilisation (BTS) and spinopelvic fixation (SP) as minimally invasive techniques for bilateral fragility fractures of the sacrum (BFFS).

METHODS

We performed a prospective, non-randomised, case-controlled study. Patients were included if they remained bedridden due to pain despite conservative treatment. Group assignment depended on sacral anatomy and fracture type. The outcome was estimated by blood loss calculation, cut-seam time, fluoroscopy time, complications, duration of stay at the intensive/intermediate care unit (ICU/IMC), and total inpatient stay. The mobility level at discharge was recorded.

RESULTS

Seventy-three patients were included (SP: 49, BTS: 24). There was no difference in blood loss (BTS: 461 ± 628 mL, SP: 509 ± 354 mL). BTS showed a significantly lower cut-seam time (72 ± 23 min) than SP (94 ± 27 min). Fluoroscopy time did not differ (BTS: 111 ± 61 s vs. 103 ± 45 s). Thirteen percent of BTS and 16% of SP patients required ICU/IMC stay (BTS: 0.6 ± 1.8 days, SP: 0.5 ± 1.5 days) during inpatient stay (BTS: 9 ± 4 days, SP: 8 ± 3 days). Fourteen patients suffered from urinary tract infections (BTS: 8%; SP: 25%). In-patient mortality was low (BTS: 4.2%, SP: 4.1%). At discharge, the BTS group was almost back to the initial mobility level. In SP patients, mobility was significantly lower than before complaints (p = 0.004).

CONCLUSION

Both methods allow early mobilization of BFFS patients. Blood loss can be kept low. Hence, transfusion requirement is correspondingly low. The IMC/ICU and the total inpatient stay are lower than reported in the literature. Both BTS and SP can be recommended as safe and low-complication methods for use in BFFS patients. BTS is superior to SP with respect to surgery duration and level of mobility at discharge.

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.

A Review on Management of Insufficiency Fractures of the Pelvis and Acetabulum

"Insufficiency fractures of the pelvis and acetabulum are occurring at increasing rates. Osteoporosis is the most prevalent risk fracture. Diagnosis begins with plain radiographs followed by advanced imaging with computed tomography and/or MRI. Pelvic ring fragility injuries are classified by the Fragility fractures of the pelvis system. Elderly acetabular fractures may be classified by the Letournel system. Management of these injuries is primarily nonoperative with early immobilization when allowed by fracture characteristics. When warranted, percutaneous fixation and open reduction internal fixation are options for both. Both acute and delayed total hip arthroplasty are options for acetabular fractures."

Fragility Fractures of the Pelvis and Sacrum: Current Trends in Literature

Fragility fractures of the pelvis (FFP) and fragility fractures of the sacrum (FFS), which are emerging in the geriatric population, exhibit characteristics that differ from those of pelvic ring disruptions occurring in the younger population. Treatment of FFP/FFS by a multidisciplinary team can be helpful in reducing morbidity and mortality with the goal of reducing pain, regaining early mobility, and restoring independence for activities of daily living. Conservative treatment, including bed rest, pain therapy, and mobilization as tolerated, is indicated for treatment of FFP type I and type II as loss of stability is limited with these fractures. Operative treatment is indicated for FFP type II when conservative treatment has failed and for FFP type III and type IV, which are displaced fractures associated with intense pain and increased instability. Minimally invasive stabilization techniques, such as percutaneous fixation, are favored over open reduction internal fixation. There is little evidence regarding outcomes of patients with FFP/FFS and more literature is needed for determination of optimal management. The aim of this article is to provide a concise review of the current literature and a discussion of the latest recommendations for orthopedic treatment and management of FFP/FFS.

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.

Operative management of fragility fractures of the pelvis - a systematic review

Background

The incidence of osteoporotic pelvic fractures in elderly patient is rising. This brings an increasing burden on health and social care systems as these injuries often lead to prolonged hospital admissions, loss of independence, morbidity and mortality. Some centres now advocate stabilisation of these injuries to reduce pain, facilitate early mobilisation, decrease hospital stay and restore independence. A systematic review of the literature was planned to establish the evidence for this intervention.

Methods

A systematic review was performed according to PRISMA guidelines. A clinical librarian performed a search of the following databases: NHS Evidence, TRIP, the Cochrane Database of Systematic Reviews, MEDLINE and EMBASE. Seventeen eligible studies were identified with 766 patients.

Results

The quality of evidence was poor with no good quality randomised trials. The majority of injuries were minimally displaced. Posterior ring injuries were most often stabilised with percutaneous screws which were sometimes augmented with void filler. A number of techniques were described for stabilisation of the anterior ring although fixation of the anterior ring was frequently not performed.

There was consistent evidence from the included studies that operative intervention significantly improved pain. Complications were minimal but there were increased failure rates when a single unaugmented sacroiliac joint screw was used. The limited availability of non-operative comparators made it difficult to draw firm conclusions about the efficacy of surgical over non-surgical management in these patients.

Conclusions

Operative management of fragility fractures of the pelvis should be considered for patients failing a brief period of non-operative management, however prospective randomised trials need to be performed to provide improved evidence for this intervention. Surgeons should consider which fixation techniques for fragility fractures of the pelvis are robust enough to allow immediate weightbearing, whilst minimising operative morbidity and post-operative complications.

PROSPERO Systematic Review ID: CRD42020171237.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-021-04579-w.

Iliac Bone Corridors to Host the Transiliac Internal Fixator-An Experimental CT Based Analysis

Background: The transiliac internal fixator (TIFI) is a novel minimally invasive surgical procedure to stabilize posterior pelvic ring fractures. Two bone corridors with different lengths, widths, and angulations are suitable to host screws in the posterior iliac wing. While the length and the width have been described previously, the angulation has not been determined yet. Methods: We created a computer tomography-based 3D-model of 40 patients (20 women, 20 men). The possible bone corridors to host the ilium screws for the TIFIcc (cranio-caudal) and the TIFIdv (dorso-ventral) procedure were identified. After reaching the optimal position, the angles in relation to the sagittal and axial plane were measured. The anterior pelvic plane was chosen as the reference plane. Results: The mean angle of the TIFIcc screws related to the axial plane was 63.4° (±1.8°) and to the sagittal plane was 12.3° (±1.5°). The mean angle of the TIFIdv screws related to the axial plane was 16.1° (±1.2°) and to the sagittal plane was 20.1° (±2.0°). In each group, a high constancy was apparent irrespective of the age or physical dimension of the patient, although a significant gender-dependent difference was observed”. Conclusions: Due to a high inter-individual constancy in length, width, and angulation, bone corridors in the posterior iliac wing are reliable to host screws for posterior pelvic ring fixation irrespective of each individual patient’s anatomy.

Mid-term outcome of bilateral fragility fractures of the sacrum after bisegmental transsacral stabilization versus spinopelvic fixation

AIMS

Minimally invasive fixation of pelvic fragility fractures is recommended to reduce pain and allow early mobilization. The purpose of this study was to evaluate the outcome of two different stabilization techniques in bilateral fragility fractures of the sacrum (BFFS).

METHODS

A non-randomized, prospective study was carried out in a level 1 trauma centre. BFFS in 61 patients (mean age 80 years (SD 10); four male, 57 female) were treated surgically with bisegmental transsacral stablization (BTS; n = 41) versus spinopelvic fixation (SP; n = 20). Postoperative full weightbearing was allowed. The outcome was evaluated at two timepoints: discharge from inpatient treatment (TP1; Fitbit tracking, Zebris stance analysis), and ≥ six months (TP2; Fitbit tracking, Zebris analysis, based on modified Oswestry Disability Index (ODI), Majeed Score (MS), and the 12-Item Short Form Survey 12 (SF-12). Fracture healing was assessed by CT. The primary outcome parameter of functional recovery was the per-day step count; the secondary parameter was the subjective outcome assessed by questionnaires.

RESULTS

Overall, no baseline differences were observed between the BTS and SP cohorts. In total, 58 (BTS = 19; SP = 39) and 37 patients (BTS = 14; SP = 23) could be recruited at TP1 and TP2, respectively. Mean steps per day at TP1 were median 308 (248 to 434) in the BTS group and 254 (196 to 446) in the SP group. At TP2, median steps per day were 3,759 (2,551 to 3,926) in the BTS group and 3,191 (2,872 to 3,679) in the SP group, each with no significant difference. A significant improvement was observed in each group (p < 0.001) between timepoints. BTS patients obtained better results than SP patients in ODI (p < 0.030), MS (p = 0.007), and SF-12 physical status (p = 0.006). In all cases, CT showed sufficient fracture healing of the posterior ring.

CONCLUSION

Both groups showed significant outcome improvement and sufficient fracture healing. Both techniques can be recommended for BFFS, although BTS was superior with respect to subjective outcome. Step-count tracking represents a reliable method to evaluate the mobility level. Cite this article: Bone Joint J 2021;103-B(3):462-468.

[Clinical outcome and revenue situation after conservative, interventional and surgical/osteosynthetic treatment of sacral insufficiency fractures]

BACKGROUND

Insufficiency fractures of the sacrum are being detected increasingly more frequently, whereby their incidence will no doubt increase further as a result of the rise in life expectancy.

OBJECTIVE

The clinical appearance of sacral insufficiency fractures, the treatment approach taking into account the clinical outcomes and the DRG proceeds are discussed on the basis of clinical examples.

PATIENTS AND METHODS

Three female patients (average age 78.3 years) with sacral insufficiency fractures were admitted for inpatient treatment due to increasing disabling pain. Taking into account the clinical symptoms and the recommendation of an interdisciplinary case conference, one patient was treated conservatively with short-term bed rest, accompanying analgesic medication and pain-adapted exercise measures. The second patient underwent computed tomography (CT)-guided balloon sacroplasty. Transsacroiliac screw fixation was performed on the third patient. Pain was documented over the course on a visual analogue scale (VAS) and the degree of independence on the Barthel scale. The fractures were classified according to Denis et al. and the classification of the FFP according to Rommens and Hofmann. The DRG revenue for the 2020 accounting period was then presented for each case.

RESULTS

Patient No. 1: conservative therapy, unilateral Denis 1 fracture zone, corresponding to an FFP type IIa, baseline pain 7 score points, at discharge 4 score points, the Barthel scale increased from 55 to 75 points. After 6 days hospitalization, transferred to rehab. The DRG proceeds were € 3817.95. Patient No. 2: balloon sacroplasty, bilateral Denis 1-2 fracture zone, corresponding to an FFP type IIa, baseline pain 9 score points, at discharge 2 score points, the Barthel scale increased from 35 to 95 points. After 4 days hospitalization, discharged to outpatient follow-up treatment. The DRG proceeds were € 7409.44. Patient No. 3: osteosynthesis, bilateral Denis 1 fracture zone, corresponding to an FFP type IIa, baseline pain 7 score points, at discharge 2 score points, the Barthel scale increased from 40 to 90 points. After 5 days hospitalization, transferred to rehab. The DRG proceeds were € 6714.30.

CONCLUSION

The sacral insufficiency fracture is a strong indicator for the presence of manifest osteoporosis. Fracture risk factors are the female sex, advanced age, the presence of osteoporosis and vitamin D deficiency. Conservative therapy is the first step of the treatment cascade; however, in patients with persistent, disabling pain and no potential for mobilization, sacroplasty or osteosynthesis should be performed at an early stage. In patients treated with coordinated therapy processes and without clinical complications, all three treatment options are economically sufficient.

Gender-Associated Differences in Sacral Morphology Do Not Affect Feasibility Rates of Transsacral Screw Insertion. Radioanatomic Investigation Based on Pelvic Cross-sectional Imaging of 200 Individuals

STUDY DESIGN

Retrospective radioanatomic single-center cohort study.

OBJECTIVE

To investigate sex-specific differences in transsacral corridor dimensions, determine feasibility rates of transsacral screw placement without extended safety zones around planned screw positions, and develop an index defining sacral dysmorphism (SD) irrespective of transsacral corridor diameters.

SUMMARY OF BACKGROUND DATA

Previously reported SD definitions used radiologically identifiable pelvic characteristics or predefined minimum diameter thresholds of transsacral corridors in the upper sacral segment including safety zones for screw placement. Technical progress of surgical 3D image guidance improved sacral screw insertion accuracy questioning established minimum diameter threshold-based SD definitions.

METHODS

Datasets from cross-sectional pelvic imaging of 100 women and 100 men presenting to a general hospital from July 2018 through August 2018 were included in a database to evaluate transsacral trajectory rates, and dimensions of transsacral corridor lengths, widths (TSCWs), and heights (TSCHs) in sacral segments I to III (S1-3). SD was assumed, if no transsacral trajectory was found in S1 with a corridor diameter of at least 7.5 mm.

RESULTS

Women presented significantly higher rates of transsacral trajectories in the inferior sector of S1 (P = 0.03), and larger transsacral corridor lengths in S2 (superior sector, P = 0.045), and S3 (central position, P = 0.02). In men, significantly higher feasibility rates were found for the placement of two transsacral screws in S2 (P = 0.0002), and singular screws in S3 (P = 0.006), with larger S1- (P = 0.0002), and central S2-TSCWs (P = 0.006). SD was prevalent in 17% of women, and 16% of men (P = 0.85). Calculating TSCW ratios of S1 and S2 was significantly indicative for SD at values below a threshold of 0.8 in women (P < 0.00001), and men (P = 0.0004).

CONCLUSION

SD is independent of sex despite significant differences in sacral morphology. An index defining SD irrespective of absolute transsacral corridor dimensions is presented to reliably differentiate dysmorphic from nondysmorphic sacra in women and men.

LEVEL OF EVIDENCE

2.

When and How to Operate Fragility Fractures of the Pelvis?

Fragility fractures of the pelvis (FFP) are an entity with an increasing frequency. The characteristics of these fractures are different from pelvic ring fractures in younger adults. There is a low energy instead of a high energy trauma mechanism. Due to a specific and consistent decrease of bone mineral density, typical fractures in the anterior and posterior pelvic ring occur. Bilateral sacral ala fractures are frequent. A new classification system distinguishes between four categories with increasing loss of stability. The subtypes represent different localizations of fractures. The primary goal of treatment is restoring mobility and independency. Depending on the amount of instability, conservative or surgical treatment is recommended. The operative technique should be as less invasive as possible. When the broken posterior pelvic ring is fixed operatively, a surgical fixation of the anterior pelvic ring should be considered as well. FFP Type I can be treated conservatively. In many cases, FFP Type II can also be treated conservatively. When conservative treatment fails, percutaneous fixation is performed. FFP Type III and FFP Type IV are treated operatively. The choice of the operation technique is depending on the localization of the fracture. Iliosacral screw osteosynthesis, transsacral bar osteosynthesis, transiliac internal fixation, and iliolumbar fixation are alternatives for stabilization of the posterior pelvic ring. Plate osteosynthesis, retrograde transpubic screw, and anterior internal fixation are alternatives for stabilization of the anterior pelvic ring. Postoperatively, early mobilization, with weight bearing as tolerated, is started. Simultaneously, bone metabolism is also analyzed and its defects compensated. Medical comorbidities should be identified and treated with the help of a multidisciplinary team.

Surgical Fixation of Geriatric Sacral U-Type Insufficiency Fractures: A Retrospective Analysis

OBJECTIVES

To define the incidence of sacral U-type insufficiency fracture and describe management of a consecutive series of patients with this injury.

DESIGN

Retrospective analysis.

SETTING

Single Level II trauma center.

PATIENTS/PARTICIPANTS

Sixteen adult patients with sacral U-type insufficiency fractures treated over a 36-month period.

INTERVENTION

Patients were indicated for percutaneous screw fixation of the posterior pelvis if they had posterior pelvic pain that prohibited mobilization.

MAIN OUTCOME MEASUREMENTS

Visual analog scale for pain, distance ambulated on postoperative day 1, and change in sacral kyphosis.

RESULTS

The sacral U-type insufficiency fracture incidence was 16.7% (19/114); average patient age was 75 years. Delayed surgery was performed after primary nonoperative treatment had failed in 62.5% (10/16) at an average 83 days postinjury. Acute surgery was performed in 37.5% (6/16) at an average 5 days postinjury. Distance ambulated on postoperative day 1 was 114.4 feet [95% confidence interval (CI) (50.6, 178.2)] and 88.7 feet [95% CI (2.8, 174.6)] in the delayed and acute surgery groups, respectively, P = 0.18. Change in visual analog scale for pain was -3.2 [95% CI (-5.0, -1.4)] and -3.7 [95% CI (-7.0, -0.4)] in the delayed and acute surgery groups, respectively, P = 0.15. Change in sacral kyphosis from presentation to surgery was 12.3 degrees [95% CI (6.7, 17.9)] and 0.3 degrees [95% CI (-0.2, 0.9)] in the delayed and acute surgery groups, respectively, P < 0.01. Minimum follow-up was 12 months.

CONCLUSIONS

Treatment of sacral U-type insufficiency fractures by percutaneous screw fixation permits early mobilization, provides rapid pain relief, and prevents progressive deformity.

LEVEL OF EVIDENCE

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

Fragility fractures of the sacrum occur in elderly patients with severe loss of sacral bone mass

INTRODUCTION

Patients suffering from osteoporosis-associated fragility fractures of the sacrum (FFS; also termed sacral insufficiency fractures) are increasingly observed. They have typical fracture patterns with fracture lines located in the sacral ala. When treating these patients operatively, iliosacral screw loosening is not uncommon. We aimed to study the sacral bone mass in patients presenting with a FFS using 3D statistical models.

MATERIALS AND METHODS

3D models of averaged Hounsfield units (HU) were generated based on CT scans from 13 patients with a unilateral FFS (mean age 79.6 years; 11 females, 2 males). The control group without fractures consisted of 28 males and 32 females (mean age of 68.3 years). A virtual bone probe along the trans-sacral corridors S1 and S2 was taken.

RESULTS

The bone mass distribution in the fractured sacra was similar to the control group, however, with overall lower HU. Large zones of negative HU were located in the sacral ala. In the fractured sacra, the HU in the sacral ala was significantly lower on the non-injured side when comparing to the fractured side (p < 0.001) as well as compared to the non-fractured group (p < 0.001). Low bone mass was observed in sacral body S1 (40 HU) and S2 (20 HU).

CONCLUSIONS

The extensive area of negative HU may explain the fracture location in the sacral ala. The low HU in the sacral bodies advocates the use of trans-sacral implants or augmented iliosacral screws to enhance the strength of fracture fixation. The increased HU in the fractured ala could be explained by fracture-asssociated hemorrhage and can be used as a diagnostic tool.

[Quantification of treatment success for geriatric sacral fractures]

BACKGROUND

Geriatric sacral fractures represent an independent fracture entity of increasing incidence and growing socioeconomic relevance. The goals of treatment are very different to those in younger patients with high-energy pelvic fractures. Hence, new outcome measurement instruments are required in order to assess the success of treatment.

OBJECTIVE

Literature review summarizing existing concepts and providing an overview of outcome measurement instruments for geriatric sacral fractures.

METHODS

Narrative review article based on an analysis of the German and English-speaking literature from the last 10 years.

RESULTS

Geriatric sacral fractures result in impaired mobility, increased physical and social loss of dependency and increased morbidity and mortality rates. There is a lack of standardized specific assessment procedures for functional outcome measurement after geriatric sacral fractures. Until these are developed and validated, a parallel acquisition of mortality, the timed up and go test, the Oswestry disability index (ODI) and a generic healthcare questionnaire score (SF-36, EQ-5D) seem to be most suitable.

CONCLUSION

At present our knowledge about the natural course of geriatric sacral fractures is limited by the lack of well-validated instruments to measure functional and radiographic outcomes. This has to be considered when evaluating the success of new treatment options for these patients. Future studies should validate existing scores for this population and develop new specific outcome instruments.

Clinical application of a minimally invasive cement-augmentable Schanz screw rod system to treat pelvic ring fractures

PURPOSE

The purpose of this study is to analyze the results using the USS fracture MIS system (DePuy Synthes) to treat instable pelvic ring fractures. As its outstanding feature, it is the only Schanz screw and rod system at present that combines angular stability, perforation/fenestration of the screws for cement-augmentation, a variable screw length, and a large screw diameter.

MATERIALS AND METHODS

Retrospective investigation of 134 pelvic ring fractures treated in 2012-2013. Twenty-five patients obtained the abovementioned implant. Besides baseline characteristics of the included patients and the surgical procedure, a clinical/radiological follow-up of six months was analyzed.

RESULTS

Dividing the collective into two groups, I high-energy trauma and II fragility fracture of the pelvis, the following results were recorded: group I: ten patients, six male, age 48.4 ± 19.7 years. Mean ISS 41 ± 22.5, fracture classification: AO/OTA type 61 B₁/C₁/C₃ = 1/5/4. Operative treatment: three transiliac internal fixator, seven iliolumbar fixation, one implant was cement-augmented. Group II: 15 patients, 14 female, age 77.5 ± 10.1 years. Fracture classification according to Rommens: FFP_II/_III/_IV = 6/1/8. Operative treatment: eight transiliac internal fixator, seven iliolumbar fixation, 14 implants were cement-augmented. Overall surgical side complications: 16%. Radiological examination: correct positioning of all ilium screws. Follow-up after six month (16 patients): all showed fracture consolidation. One ilium screw was broken close to the connecting clamp.

CONCLUSION

The investigated Schanz screw rod system is a suitable implant to broaden the established procedures to stabilize dorsal pelvic ring fractures.

TRIAL REGISTRATION

The study is registered at the Clinical Trial Registry University of Regensburg (Number Z-2017-0878-3).

Transsacral-Transiliac Screw Stabilization: Effective for Recalcitrant Pain Due to Sacral Insufficiency Fracture

OBJECTIVES

To evaluate the effectiveness of transsacral-transiliac screw fixation for the treatment of sacral insufficiency fractures that fail nonoperative treatment.

DESIGN

A pilot study series of consecutive patients identified over 5 years were treated and followed prospectively.

SETTING

Academic-affiliated, tertiary referral, level 1 trauma center in Dallas, TX.

PATIENTS/PARTICIPANTS

Patients were selected on the basis of presenting diagnosis, and failure of nonoperative treatment of their sacral insufficiency fracture. Eleven patients entered to the study, and 10 completed follow-up.

INTERVENTION

Placement of transsacral-transiliac screws for sacral insufficiency fracture.

MAIN OUTCOME MEASUREMENTS

Comparison of preoperative and postoperative Visual Analog Scale scores and Oswestry Low Back Disability Index scores.

RESULTS

Patients experienced statistically significant improvement in both outcome measures after intervention. No complications encountered.

CONCLUSIONS

Transsacral-transiliac screw fixation seems to be a safe and effective treatment for sacral insufficiency fractures recalcitrant to nonoperative management.

LEVEL OF EVIDENCE

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

In-screw cement augmentation for iliosacral screw fixation in posterior ring pathologies with insufficient bone stock

BACKGROUND

Minimal invasive screw fixation is common for treating posterior pelvic ring pathologies, but lack of bone quality may cause anchorage problems. The aim of this study was to report in detail a new technique combining iliosacral screw fixation with in-screw cement augmentation (ISFICA).

DESCRIPTION OF TECHNIQUE

The patient was put under general anesthesia and placed in the supine position. A K-wire was inserted under inlet-outlet view to guide the fully threaded screw. The screw placement followed in adequate position. Cement was applied through a bone filler device, inserted at the screwdriver. The immediate control of cement distribution, accurate screw placement and potential leakage were obtained via intraoperative CT scan.

PATIENTS AND METHODS

Twenty consecutive patients treated with ISFICA were included in this study. The mean age was 74.4 years (range 48-98). Screw placement, possible cement leakage and screw positioning were evaluated via intraoperative CT scan. Postoperative neurologic deficits, pain reduction and immediate postoperative mobilization were clinically evaluated.

RESULTS

Twenty-six screws were implanted. All patients were postoperatively, instantly mobilized with reduced pain. No neurologic deficits were apparent postoperatively. No cement leakage occurred. One breach of the iliac cortical bone was noted due to severe osteoporosis. One screw migration was seen after 1 year and two patients showed iliosacral joint arthropathy, which led to screw removal.

CONCLUSION

ISFICA is a very promising technique in terms of safety, precision and initial postoperative outcome. Long-term outcomes such as lasting mechanical stability or pain reduction and screw loosening despite cement augmentation should be investigated in further studies with larger patient numbers.

Sacral Bone Mass Distribution Assessed by Averaged Three-Dimensional CT Models: Implications for Pathogenesis and Treatment of Fragility Fractures of the Sacrum

BACKGROUND

Fragility fractures of the sacrum are increasing in prevalence due to osteoporosis and epidemiological changes and are challenging in their treatment. They exhibit specific fracture patterns with unilateral or bilateral fractures lateral to the sacral foramina, and sometimes an additional transverse fracture leads to spinopelvic dissociation. The goal of this study was to assess sacral bone mass distribution and corresponding changes with decreased general bone mass.

METHODS

Clinical computed tomography (CT) scans of intact pelves in ninety-one individuals (mean age and standard deviation, 61.5 ± 11.3 years) were used to generate three-dimensional (3D) models of the sacrum averaging bone mass in Hounsfield units (HU). Individuals with decreased general bone mass were identified by measuring bone mass in L5 (group 1 with <100 HU; in contrast to group 2 with ≥100 HU).

RESULTS

In group 1, a large zone of negative Hounsfield units was located in the paraforaminal lateral region from S1 to S3. Along the trans-sacral corridors, a Hounsfield unit peak was observed laterally, corresponding to cortical bone of the auricular surface. The lowest Hounsfield unit values were found in the paraforaminal lateral region in the sacral ala. An intermediate level of bone mass was observed in the area of the vertebral bodies, which also demonstrated the largest difference between groups 1 and 2. Overall, the Hounsfield units were lower at S2 than S1.

CONCLUSIONS

The models of averaged bone mass in the sacrum revealed a distinct 3D distribution pattern.

CLINICAL RELEVANCE

The negative values in the paraforaminal lateral region may explain the specific fracture patterns in fragility fractures of the sacrum involving the lateral areas of the sacrum. Transverse fractures located between S1 and S2 leading to spinopelvic dissociation may occur because of decreased bone mass in S2. The largest difference between the studied groups was found in the vertebral bodies and might support the use of transsacral or cement-augmented implants.

Anatomical considerations for percutaneous trans ilio-sacroiliac S1 and S2 screw placement

OBJECTIVE

To determine the presence of a consistent osseous corridor through S1 and S2 and fluoroscopic landmarks thereof, which could be used for safe trans ilio-sacroiliac screw fixation of posterior pelvic ring disorders.

STUDY DESIGN

Computed tomography (CT) based anatomical investigation utilising multiplanar image and trajectory reconstruction (Agfa-IMPAX Version 5.2 software). Determination of the presence and dimension of a continuous osseous corridor in the coronal plane of the sacrum at the S1 and S2 vertebral levels.

OUTCOME MEASURES

Determination of: (a) the presence of an osseous corridor in the coronal plane through S1 and S2 in males and females; (b) the dimension of the corridor with regard to diameter and length; (c) the fluoroscopic landmarks of the corridor.

RESULTS

The mean cross-sectional area for S1 corridors in males and females was 2.13 and 1.47 cm(2) , respectively. The mean cross-sectional area for the S2 corridor in males and females was 1.46 and 1.13 cm(2), respectively. The limiting anatomical factor is the sagittal diameter of the sacral ala at the junction to the vertebral body. The centre of the S1 and S2 corridor is located in close proximity to the centre of the S1 and S2 vertebrae on the lateral fluoroscopic view as determined by the adjacent endplates and anterior and posterior vertebral cortices.

CONCLUSION

Two-thirds of males and females have a complete osseous corridor to pass a trans-sacroiliac S1 screw of 8 mm diameter. The S2 corridor was present in all males but only in 87 % of females. Preoperative review of the axial CT slices at the midpoint of the S1 or S2 vertebral body allows the presence of a trans-sacroiliac osseous corridor to be determined by assessing the passage at the narrowest point of the corridor at the junction of the sacral ala to the vertebral body.

The cement-augmented transiliacal internal fixator (caTIFI): an innovative surgical technique for stabilization of fragility fractures of the pelvis

INTRODUCTION

Analyzing the different age groups in a population who suffered a pelvic ring fracture it becomes obvious that there are important differences between the pelvic ring lesions of an elderly patient compared to a young adult concerning trauma mechanism, fracture pattern and therapeutic options. In the elderly patient it is very important to achieve maximum of stability if surgery is necessary in order to avoid early failure of the ostheosynthesis under mobilization with full weight bearing.

PATIENTS AND METHODS

15 patients (14 female) with fragility fractures of the pelvis that required surgical stabilization were eligible to participate in this study from December 2012 to December 2014. Such details were documented and analysed as patient demographics, mechanism of injury, fracture classification, operative treatment and postoperative radiological parameters of achieved bone-implant interface.

RESULTS

The average age of the patients was 79.9 years (SD 9.0 years). According to Rommens five patients had a fragility fracture of the pelvis Type II-c, one a Type III-c, six a Type IV-b and three a Type IV-c. Four patients were treated by a cement augmented transiliac internal fixation (caTIFI). Seven patients received a cement augmented iliolumbar fixation. In all these patients the Schanz screws applied to the ilium were placed in an oblique dorsoventral direction into the supraacetabular bone canal (mean length of screws 100 ± 20mm, max. 135 mm, min. 70 mm). Even though in four patients the iliosacral joint was hit tangential and one cortex perforation without any cement leakage appeared no revision surgery was necessary. Overall the clinical findings including mobilisation with full weight bearing showed a sufficient mechanically stability in all patients.

CONCLUSION

The focus of this study was to describe the modified surgical technique of the caTIFI with placing the Schanz screws from the posterior superior iliac spine to the anterior inferior iliac spine into the supraacetabular bone canal. Usage of cannulated and perforated Schanz screws gives the opportunity to control the correct position of the screws before implanting them. Another advantage is that additional stability can be obtained by cement augmentation. We believe that the new technique of the caTIFI provides a greater intraoperative versatility and a greater mechanical stability for fragility fractures of the pelvis.

Percutaneous iliosacral screw fixation after osteoporotic posterior ring fractures of the pelvis reduces pain significantly in elderly patients

INTRODUCTION

Osteoporotic posterior ring fractures of the pelvis are common injuries in the elderly, but the treatment of these fractures still remains controversial. Percutaneous iliosacral screw fixation is one surgical option if conservative treatment cannot provide sufficient pain reduction. The aim of this study is to provide short-term results of elderly patients with percutaneous screw fixation.

METHODS

30 patients with posterior ring fractures were treated between 12/2009 and 01/2014 with percutaneous iliosacral screw fixation. Patients' mean age was 78.4 years. Concerning short-term outcome, we focused on initial pain level and postoperative pain reduction together with intra- and postoperative complications.

RESULTS

The average hospital stay was 23.7 days, with surgical treatment performed after an average of 9.2 days. 90% of our patients were female. All 30 patients had a lower level of pain at discharge compared with admission or immediately prior to surgery. The difference in pain level at admission compared with the pain level upon discharge showed a mean reduction from 6.8 to 1.8 with a statistically significant change (P≤0.001). 24 of 30 patients had no registered complications, one screw malpositioning with postoperative nerve irritation occurred.

DISCUSSION

Conventional percutaneous iliosacral screw fixation is a successful operative treatment for elderly patients with persistent lower back pain after unstable posterior ring fractures of the pelvis. Intra- and postoperative complications are rare, so this treatment can be regarded as a safe procedure.

LEVEL OF EVIDENCE

IV (retrospective study).

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

The increasing prevalence of fragility fractures of the sacrum (FFS) occurring predominantly in osteoporotic individuals poses a diagnostic and therapeutic challenge. The clinical presentation varies from longstanding low back pain without the patient remembering a traumatic event to immobilized patients after suffering a low-energy trauma. FFS are often combined with a fracture of the anterior pelvic ring; hence they are classified as a part of fragility fractures of the pelvis (FFP). If not displaced, the patients are treated with weight bearing as tolerated and analgesics; however, we advocate to treat displaced fractures surgically according to the fracture personality and the patient’s comorbidities. Surgical options include minimal invasive sacro-iliac screws, trans-sacral bar osteosynthesis, open reduction and internal fixation, or spinopelvic stabilization. In the light of the high complication rate associated with immobilized patients, an operative approach often is indicated to accelerate the patient’s mobility.

Pelvic Insufficiency Fractures

Pelvic insufficiency fractures may occur in the absence of trauma or as a result of low-energy trauma in osteoporotic bone. With a growing geriatric population, the incidence of pelvic insufficiency fracture has increased over the last 3 decades and will continue to do so. These fractures can cause considerable pain, loss of independence, and economic burden to both the patient and the health care system. While many of these injuries are identified and treated based on plain radiographs, some remain difficult to diagnose. The role of advanced imaging in these cases is discussed. In addition to treating the fracture, medical comorbidities contributing to osteoporosis should be identified and corrected. Specific attention has been given to 25-OH serum vitamin D screening and repletion. Treatment generally consists of providing pain control and assisting patients with mobilization while allowing weight bearing as tolerated. In those unable to do so, invasive techniques such as sacroplasty as well as internal fixation may be beneficial. The role of operative fixation in insufficiency fractures is also discussed.

Anatomical conditions of the posterior pelvic ring regarding bisegmental transverse sacroiliac screw fixation: a 3D morphometric study of 125 pelvic CT datasets

INTRODUCTION

Sacroiliac (SI) screws are used for osteosynthesis in unstable posterior pelvic ring injuries. In the cases of "sacral dysplasia", in which the elevated upper sacrum does not allow a secure SI screw insertion into the S1 level, the S2 segment must be used to achieve stable fixation. The bone quality of the S2 segment is thinner compared to that of the S1 vertebra and may cause biomechanical weakness. An additional SI screw insertion into the S3 level may improve stability. With respect to the anatomical conditions of the posterior pelvic ring, there have been no anatomical investigations to date regarding SI screw placement into the third sacral segment.

MATERIALS AND METHODS

CT raw datasets from 125 patients (ø59 years, ø172 cm, ø76 kg) were post-processed using Amira 5.2 software to generate 3D pelvic models. A program code implemented in C++ computed a transverse bone corridor for the first, second and third sacral segments for a typical SI screw diameter of 7.3 mm. Volume, sagittal cross-section, iliac entrance area and length of the determined screw corridors were measured. A confidence interval of 95 % was assumed (p < 0.05).

RESULTS

The fully automatic computation revealed a possible transverse insertion for one 7.3-mm screw in the third sacral segment in 30 cases (24 %). The rate (60 %) of feasible S3 screw placements in the cases of sacral dysplasia (n = 25) is significantly higher compared to that (15 %) of "normal" sacra (n = 100). With regard to the existence of transverse iliosacroiliac corridors as a function of sacral position in between the adjacent iliac bone bilaterally, a new classification of three different shape conditions can be made: caudad, intermediate minor, intermediate major, and cephalad sacrum. Gender, age, body height and body weight had no statistically significant influence on either possible screw insertion or on the calculated data of the corridors (p > 0.05).

CONCLUSION

SI screw insertion into the third sacral level deserves discussion in the cases of sacral dysplasia. Biomechanical and practical utility must be verified.

Comprehensive classification of fragility fractures of the pelvic ring: Recommendations for surgical treatment

Due to the increasing life expectancy, orthopaedic surgeons are more and more often confronted with fragility fractures of the pelvis (FFPs). These kinds of fractures are the result of a low-energy impact or they may even occur spontaneously in patients with severe osteoporosis. Due to some distinct differences, the established classifications for pelvic ring lesions in younger adults do not fully reflect the clinical and morphological criteria of FFPs. Most FFPs are minimally displaced and do not require surgical therapy. However, in some patients, an insidious progress of bone damage leads to increasing displacement, nonunion and persisting instability. Therefore, new concepts for surgical treatment have to be developed to address the functional needs of the elderly patients. Based on an analysis of 245 consecutive patients with FFPs, we propose a novel classification system for this condition. This classification is based on morphological criteria and it corresponds with the degree of instability. Also in the elderly, these criteria are the most important for the decision on the type of treatment as well as type and extent of surgery. The estimation of the degree of instability is based on radiological and clinical findings. The classification gives also hints for treatment strategies, which may vary between minimally invasive techniques and complex surgical reconstructions.

Surgical management of osteoporotic pelvic fractures: a new challenge

The number and variety of osteoporotic fractures of the pelvis are rapidly growing around the world. Such fractures are the result of low-impact trauma. The patients have no signs of hemodynamic instability and do not require urgent stabilization. The clinical picture is dominated by immobilizing pain in the pelvic region. Fractures may be located in both the ventral and the dorsal pelvic ring. The current well-established classification of pelvic ring lesions in younger adults does not fully reflect the criteria for osteoporotic and insufficiency fractures of the pelvic ring. Most osteoporotic fractures are minimally displaced and do not require surgical therapy. However, in some patients, an insidious progress of bone damage leads to complex displacement and instability. Therefore, vertical sacral ala fractures, fracture dislocations of the sacroiliac joint, and spinopelvic dissociations are best treated with operative stabilization. Angular stable bridge plating, the insertion of a transsacral positioning bar, and iliolumbar fixation are operative techniques that have been adapted to the low bone mineral density of the pelvic ring and the high forces acting on it.

Stabilization of fatigue fractures of the dorsal pelvis with a trans-sacral bar. Operative technique and outcome

INTRODUCTION

Due to ageing of our population the number of fatigue fractures of the pelvic ring is steadily growing. These fractures are often treated with bed rest but may result in a disabling immobility with severe pain. An operative treatment is an option in these cases. The aim of operative treatment is bony healing obtained by stable fixation giving back to the patient's previous mobility. Optimal surgical treatment is currently under debate. Sacroiliac screw fixation and sacroplasty are used for stabilization of the dorsal pelvis. Due to the technique and the low density of spongious sacral bone, no or only low compression in the fracture site is obtained, which may inhibit bony healing. The trans-sacral bar compression osteosynthesis is presented as an alternative procedure. We present the outcome of 11 patients, who were treated with this method.

METHODS

The patient is placed in prone position on the operation table. Under image intensifier control, a 5mm threaded sacral bar is inserted through the body of S1 from the left to the right dorsal ilium. Nuts are placed over the bar achieving fracture compression. When anterior pelvic instability is present, an anterior osteosynthesis is also performed. Clinical and radiological outcome were evaluated one year after index surgery with different scoring systems.

RESULTS

Eleven patients (9 F and 2 M) were treated between 2005 and 2010. The mean age of the patients was 73 years at time of operation. There were no mechanical complications. Postoperatively there was a temporary nerve palsy of L5 in one case. The mean follow-up was 14 months. In all patients, a bony healing of the dorsal pelvic ring was achieved. Seven patients showed a major clinical improvement, in four patients a moderate.

CONCLUSIONS

Trans-sacral bar osteosynthesis is a promising method for stabilization of fatigue fractures of the pelvic ring. Only with this method, a high interfragmentary compression is achieved, independent of the quality of the spongious bone of the sacral body.