Surgical management of osteoporotic pelvic fractures: a new challenge

Fragility fractures of the pelvis: First 48 cases of surgical treatment at a level 1 trauma center in France

INTRODUCTION

Longer life expectancy is accompanied by a higher incidence of fragility fractures of the pelvis (FFP), which has repercussions on mortality and nursing home admissions. Given the paucity of data at French healthcare facilities, we carried out a retrospective study to (1) evaluate how surgical treatment of FFP with posterior displacement (type III and IV according to Rommens and Hofmann) affects a patient's pain, functional status and ability to stay at home and (2) evaluate the postoperative complications and mortality rate.

HYPOTHESIS

Surgery for posteriorly displaced FFP will relieve pain and preserve the patient's independence.

METHODS

All the patients over 65 years of age who were operated on for a posterior FFP between January 2015 and August 2020 were included in this prospective, single-center study. The demographics, fracture type, details of the surgical treatment, complications and mortality were analyzed. Pain (visual analog scale, VAS), functional status (Activity of Daily Living [ADL] and Instrumental Activity of Daily Living [IADL]), mobility (Parker score) and rates of nursing home admissions were compared before the fracture, after surgery and at a mean follow-up of 28 months (minimum follow-up of 1 year).

RESULTS

Forty-eight patients with a mean age of 75 years were included. Twenty-four of these patients (50%) had at least two comorbidities. The FFPs were either type IV (31/48; 65%) or type III (17/48; 35%). The mean VAS for pain was significantly lower on the first day postoperative (3.5 versus 4.8; p=0.02). This significant reduction continued upon discharge from the hospital (1.95; p=0.003) and persisted at the mean follow-up of 28 months (2.2; p=0.64). The complication rate was 15% (7/48) and the mortality rate at the final review was 15% (7/48). Among the surviving patients, 81% (29/36) returned to living at home. The ADL (5.1 versus 5.8; p=0.09), IADL (5.9 versus 6.9; p=0.15) and Parker score (6.8 versus 8.2; p=0.08) at the final review were not significantly different from the values before the fracture.

CONCLUSION

This is the first French study of patients operated on for an FPP. Fixation of posteriorly displaced fractures allows surviving patients to retain their mobility. Pain relief is achieved quickly and maintained during the follow-up period. Thus, our initial hypothesis is affirmed. The complication rate is not insignificant; given the complexity of this surgery, percutaneous treatment is preferable.

LEVEL OF EVIDENCE

IV; retrospective study.

Substitutional semi-rigid osteosynthesis technique for treatment of unstable pubic symphysis injuries: a biomechanical study

BACKGROUND/PURPOSE

The surgical fixation of a symphyseal diastasis in partially or fully unstable pelvic ring injuries is an important element when stabilizing the anterior pelvic ring. Currently, open reduction and internal fixation (ORIF) by means of plating represents the gold standard treatment. Advances in percutaneous fixation techniques have shown improvements in blood loss, surgery time, and scar length. Therefore, this approach should also be adopted for treatment of symphyseal injuries. The technique could be important since failure rates, following ORIF at the symphysis, remain unacceptably high. The aim of this biomechanical study was to assess a semi-rigid fixation technique for treatment of such anterior pelvic ring injuries versus current gold standards of plate osteosynthesis.

METHODS

An anterior pelvic ring injury type III APC according to the Young and Burgess classification was simulated in eighteen composite pelvises, assigned to three groups (n = 6) for fixation with either a single plate, two orthogonally positioned plates, or the semi-rigid technique using an endobutton suture implant. Biomechanical testing was performed in a simulated upright standing position under progressively increasing cyclic loading at 2 Hz until failure or over 150,000 cycles. Relative movements between the bone segments were captured by motion tracking.

RESULTS

Initial quasi-static and dynamic stiffness, as well as dynamic stiffness after 100,000 cycles, was not significantly different among the fixation techniques (p ≥ 0.054).). The outcome measures for total displacement after 20,000, 40,000, 60,000, 80,000, and 100,000 cycles were associated with significantly higher values for the suture technique versus double plating (p = 0.025), without further significant differences among the techniques (p ≥ 0.349). Number of cycles to failure and load at failure were highest for double plating (150,000 ± 0/100.0 ± 0.0 N), followed by single plating (132,282 ± 20,465/91.1 ± 10.2 N), and the suture technique (116,088 ± 12,169/83.0 ± 6.1 N), with significantly lower values in the latter compared to the former (p = 0.002) and no further significant differences among the techniques (p ≥ 0.329).

CONCLUSION

From a biomechanical perspective, the semi-rigid technique for fixation of unstable pubic symphysis injuries demonstrated promising results with moderate to inferior behaviour compared to standard plating techniques regarding stiffness, cycles to failure and load at failure. This knowledge could lay the foundation for realization of further studies with larger sample sizes, focusing on the stabilization of the anterior pelvic ring.

Experimental and numerical assessment of two reconstructive techniques for the fragility fractures of the pelvis type Ia

Anterior pelvic ring fractures are common in geriatric patients. The Supraacetabular External Fixator (SEF) is a relatively simple and effective surgical procedure. On the other hand, there is the option of a Subcutaneous Iliopubic Plate (SIP) osteosynthesis. Only limited comparative biomechanical data of these two devices are available. Therefore, this biomechanical study's objective was to compare the stabilizing effect of the SEF versus the SIP in a model of Fragility Fractures of the Pelvis (FFP) type Ia. A test stand for pelvic biomechanics testing that emulates the gait loading cycle with physiological relevance was used. The osteotomy on the right pelvic ring was stabilized either with the SEF or the SIP. Strain gauges were used to measure strain in the pelvic ring. The osteotomy's spatial interfragmentary displacement (SID) was monitored using a 3D digital image correlation system. The SEF stabilization reduced the SID by approximately 10%, whereas the locking SIP could reduce displacement by about 62%. Additionally, the SIP reduced the stress/strain levels by 67% in the posterior pelvic ring. We could demonstrate that the SIP is superior to SEF in treating FFP type Ia as it significantly reduced the osteotomy's SID and the strain in the posterior pelvic ring.

Analysis of the Spinopelvic Parameters in Patients with Fragility Fractures of the Pelvis

BACKGROUND

We investigated the spinopelvic parameters of lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT) and sacral slope (SS) in patients with fragility fractures of the pelvis (FFPs). We hypothesized that these parameters differ from asymptomatic patients.

METHODS

All patients treated for FFPs in a center of maximal care of the German Spine Society (DWG) between 2017 and 2021 were included. The inclusion criteria were age ≥ 60 years and the availability of a standing lateral radiograph of the spine and pelvis in which the spine from T12 to S1 and both femoral heads were visible. The baseline characteristics and study parameters were calculated and compared with databases of asymptomatic patients. The two-sample t-Test was performed with p < 0.05.

RESULTS

The study population (n = 57) consisted of 49 female patients. The mean age was 81.0 years. The mean LL was 47.9°, the mean PT was 29.4°, the mean SS was 34.2° and the mean PI was 64.4°. The mean value of LLI was 0.7. LL, LLI and SS were significantly reduced, and PI and PT were significantly increased compared to asymptomatic patients.

CONCLUSIONS

The spinopelvic parameters in patients with FFPs differ significantly from asymptomatic patients. In patients with FFPs, LL, LLI and SS are significantly reduced, and PI and PT are significantly increased. The sagittal spinopelvic balance is abnormal in patients with FFPs.

FFP: Indication for minimally invasive navigation technique

An 85-year-old female patient was transferred to our clinic for surgical treatment of a complex FFP IIc. She had suffered a ground level fall 10 days ago and was still living independently. The patient was initially treated conservatively with pain medication and immobilization in an outward hospital. Due to the clinical symptoms and complex fracture pattern a physiotherapeutic assisted mobilization was not possible. The clinical examination revealed severe bilateral pain at the anterior and posterior pelvic ring. We performed a minimally invasive and an image-guided surgical stabilization. After surgical treatment the patient was mobilized with crutches for short distances. On the third day after surgical intervention the patient was discharged from our hospital into rehabilitation. This case shows the successful use of minimally invasive and modern navigation technique for treatment of a complex FFP.

Clinical implications of additional posterior fractures in combined anterior-posterior pelvic ring fractures in elderly patients

OBJECTIVES

Historically, pelvic ring fractures (PRF) are considered to occur predominantly in the anterior ring and therfore to be mechanically stable. Combined anterior and posterior (A + P) PRF are expected to be less mechanically stable and therefore to be associated with higher levels of pain and reduced mobility compared to isolated anterior fractures. The current study investigates the clinical relevance of combined A + P PRF in elderly patients.

METHODS

A prospective multicentre cohort study was conducted in patients >70 years of age with anterior PRF after low-energy trauma diagnosed on conventional radiographs. All patients underwent an additional CT-scan. Patients were divided into two groups; isolated anterior or combined A + P fractures. Patients were treated conservatively with adequate analgesia for at least one week. If patients could not be mobilised after conservative treatment, surgical fixation was performed. Numerical Rating Scale (NRS) pain scores, dependence on walking aids and Activities of Daily Living scores (ADL) were measured at 2-4 weeks, and 3, 6 and 12 months after fracture.

RESULTS

102 patients (age 81.1 ± 7.6 years) were included. Isolated anterior fractures were diagnosed in 25 (24.5%) and A + P fractures in 77 (75.5%) patients. Baseline characteristics did not differ between the two groups. Most patients were successfully treated conservatively and 5 (4.9%) underwent percutaneous trans-iliac, trans-sacral screw fixation after failure of conservative treatment. At 2-4 weeks post trauma, patients with A + P fractures had similar median pain scores (3 (range 0-8) vs. 5 (0-10), p = 0.19) and ADL scores (85 (25-100) vs. 78.6 (5-100), p = 0.67), but were more dependent on walking aids (92.8% vs. 72.2%; p = 0.02) compared to patients with isolated anterior fractures. There were no significant differences at 3 months. At one year follow-up the median NRS pain and ADL scores for both fracture groups were 0 and 100, respectively. Mortality was 10.8%, and additional loss to follow-up was 17.6%.

CONCLUSIONS

The vast majority of elderly patients with PRF have combined A + P fractures. The clinical implications of additional posterior pelvic ring fractures in elderly patients appears to be limited.

Is the conservative treatment of sacral insufficiency fractures still up to date? Retrospective clinical observational study in 46 patients

BACKGROUND

According to current forecasts, our society will grow older and older, so that the proportion of 6% of the German population from 2017 who were 80 years or older will increase further. The frequency of falls in this patient population lead to a further increase of sacral insufficiency fractures.

HYPOTHESIS

The aim of this study is to evaluate the multimodal interdisciplinary conservative therapy regime for sacral insufficiency fractures in geriatric patients, especially on the basis of mobility and the need for assistance.

PATIENTS AND METHODS

A cohort of patients, who were treated as inpatients at the Waldkrankenhaus St. Marien in Erlangen with ICD-10 for sacral fractures S32.1 as the main diagnosis, was retrospectively examined. Only newly diagnosed sacral insufficiency fractures were taken into account. Patients were divided into groups based on the factors hospital stay, fracture location on the sacrum, and location of concomitant pelvic ring injury. The Barthel Index, the Tinetti's Mobility Test and the Timed Up&Go Test were recorded.

RESULTS

46 patients met the inclusion criteria. Using the conservative therapy, improvements were achieved in all patients in terms of need for care, mobility without aids and risk of falling, also patients with an anterior and posterior pelvic ring fracture. Regard a score improvement in the Barthel Index and Tinetti Mobility Test, patients with bilateral sacral insufficiency fracture (n=17, 37.0%) did not differ significantly from patients with unilateral sacral insufficiency fracture (n=22, 47.8%).

CONCLUSION

In geriatric patients, decisions about therapy should always be made on an individual and interdisciplinary basis. The conservative therapy regimen continues to play an important role in this. The collected tests-consisting of Barthel Index, Tinetti Mobility Test and Timed Up&Go Test-are well suited for further reproducible, objective studies with a larger patient collective.

LEVEL OF EVIDENCE

IV.

The ideal site of cement application in cement augmented sacroiliac screw fixation: the biomechanical perspective

Purpose

To compare construct stability of cement augmented sacroiliac screws using two different cementation sites in a biomechanical fragility fracture model of the pelvis.

Methods

A fracture model with an incomplete fracture of the sacral ala and complete fracture of the anterior pelvic ring mimicking a FFP IIB fragility fracture of the pelvis was established in five fresh frozen human cadaveric pelvises. Sacral fracture stabilization was achieved with bilateral 7.3 mm fully threaded sacroiliac screws. Cement augmentation was performed at the tip of the screw (body of S1; Group A) on one side, and at the midshaft of the screw (sacral ala; Group B) on the contralateral side. Biomechanical testing was conducted separately on both sides comprising cyclic loading of axial forces transferred through the tested hemipelvis from L5 to the ipsilateral acetabulum. Combined angular displacement in flexion and internal rotation (“gap angle”), angular displacement of the ilium in relation to the screw (“screw tilt ilium”), and screw tip cutout were evaluated.

Results

Relative interfragmentary movements were associated with significantly higher values in group A versus group B for “gap angle” (2.4° vs. 1.4°; p < 0.001), and for “screw tilt ilium” (3.3° vs. 1.4°; p < 0.001), respectively. No significant difference was indicated for screw tip cutout between the two groups (0.6 mm [Group A] vs. 0.8 mm [Group B]; p = 0.376).

Conclusion

The present study demonstrated less fragment and screw displacements in a FFP IIB fracture model under physiologic cyclic loading by cement augmentation of sacroiliac screws at the level of the lateral mass compared to the center of vertebral body of S1.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

[Sacral fractures in geriatric patients]

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

ASSERT (Acute Sacral inSufficiEncy fractuRe augmenTation): randomised controlled, feasibility trial in older people

OBJECTIVE

To determine the feasibility of designing and conducting a definitive trial to evaluate the effectiveness of sacral fracture fixation compared with non-surgical management among older people admitted with a lateral compression pelvic fragility fracture (PFF).

DESIGN

Single-site, parallel, two-arm randomised controlled feasibility trial.

SETTING

A UK tertiary centre hospital.

PARTICIPANTS

Patients aged ≥70 years who were ambulating pre-injury requiring hospital admission (within 28 days of injury) with a type 1 lateral compression PFF.

INTERVENTIONS

The intervention group received sacral fracture fixation (cement augmentation±screw fixation) within 7 days of randomisation. Routine preoperative and postoperative care followed each surgical intervention. The control group received usual care consisting of analgesia, and regular input from the medical and therapy team.

PRIMARY AND SECONDARY OUTCOME MEASURES

The feasibility outcomes were the number of eligible patients, willingness to be randomised, adherence to allocated treatment, retention, data on the completeness and variability of the proposed definitive trial outcome measures, and reported adverse events.

RESULTS

241 patients were screened. 13 (5.4%) were deemed eligible to participate. Among the eligible participants, nine (69.2%) were willing to participate. Five participants were randomised to the intervention group and four to the control group. The clinicians involved were willing to allow their patients to be randomised and adhere to the allocated treatment. One participant in the intervention group and two participants in the control group received their allocated treatment. All participants were followed up until 12 weeks post-randomisation, and had an additional safety follow-up assessment at 12 months. Overall, the proportion of completeness of outcome measures was at least 75%. No adverse events were directly related to the trial.

CONCLUSIONS

There were significant challenges in recruiting sufficient participants which will need to be addressed prior to a definitive trial.

TRIAL REGISTRATION NUMBER

ISRCTN16719542.

Indications for surgical fixation of low-energy pelvic ring fractures in elderly: a systematic review

INTRODUCTION

There are no generally accepted criteria for when and how to fixate osteoporotic pelvic ring fractures in elderly. This systemic review aims to summarize the currently available literature regarding the indications and methods for surgical fixation of fragility fractures of the pelvic ring in elderly patients after low-energy trauma.

MATERIALS AND METHODS

The Pubmed and Embase databases were searched using the key words pelvic fractures, geriatric, fragility, osteoporosis, and surgical fixation, and their synonyms. Extracted data including the indication, method of operative fixation, and post-operative outcomes (pain levels, mobility, complications and mortality) were analyzed using descriptive statistics. The studies were too heterogeneous to perform a meta-analysis.

RESULTS

Eleven cohort studies (3 comparative and 8 noncomparative) were included. The methodological quality was poor to moderate; the studies were heterogeneous regarding study design and reported outcomes. In all included studies operative treatment for all fracture types was preceded by a period of conservative treatment comprising physiotherapy-guided full weight-bearing. Time to surgery differed widely. For posterior ring fixation, the majority of the included studies used minimally invasive surgery with trans-iliosacral screws. Five studies described a form of additional fixation of the anterior pelvic ring but did not report the indications.

CONCLUSIONS

Fixation of low-energy pelvic ring fractures in elderly is commonly performed after a period of conservative treatment, with persistent pain as the most frequent indication for fixation. Fracture classification based on stability seems to be of secondary importance. Timing for surgical fixation of the pelvic ring fracture in elderly patients remains diverse. Large well-designed comparative prospective studies and randomized controlled trials are needed to provide clearly substantiated guidelines.

The surgical treatment of unstable osteoporotic pelvic ring fractures with bilateral vertebropelvic stabilization using a less invasive technique

By immobilizing the joint partners between the lumbar spine and the pelvis, the vertical and horizontal forces on the sacrum are both transferred through the ilium caudally. Therefore persistent stress on the fracture is avoided. To ensure sufficient soft tissue coverage the pedicle screws are inserted via small incisions in the lumbar spine area and the iliac screws via slightly oblique incisions on both sides laterally of the posterior iliac spine. At the end the instrumentation is completed by connecting the lumbar longitudinal carriers with the cross connection between the two iliac screws via the pre-existing incisions. Due to this less invasive technique, disorders of wound healing can be avoided. Due to the lower Morbidity rate and its associated reduction in blood loss, there is corresponding decrease in the number of postoperative symptoms, which has a positive effect on early mobilization. None of the described patients showed neurological deficits preoperatively or postoperatively. LEVEL OF EVIDENCE: IV; Technical note, retrospective.

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.

The FFP-classification: From eminence to evidence

Fragility fractures of the pelvis (FFP) are a clinical entity with a rapidly growing incidence among elderly women. The characteristics of these fractures are different from those appearing after high-energy trauma. In 2013, the comprehensive FFP-classification provided a new framework for analysis of these fractures. It is based on the estimation of loss of stability in the pelvic ring. It is connected with recommendations for surgical treatment, justified by the fact that higher instabilities will need surgical stabilization. Since ist appearance, we can observe an increasing clinical-scientific interest in FFP. Multiple publications use the FFP-classification studying the characteristics of fractures, choice of treatment and outcome. Other studies focus on minimal-invasive techniques for stabilization. The actual knowledge describes higher mortality rates as the reference population, lower mortality rates after operative treatment but for the price of surgery-related complications. Mobility, independency and quality of life are worse than before the fracture, independent of the FFP-classification and the type of treatment. The classification triggered a rapid increase of expertise. This publication gives a detailed overview on the evolution from eminence to evidence.

Anatomical evaluation of the transpubic screw corridor based on a 3D statistical model of the pelvic ring

Retrograde transpubic screw fixation is a common procedure for the treatment of anterior pelvic ring fractures. With its sparing surgical approach and significant pain relief after screw fixations allowing early mobilisation, it has gained importance especially in the treatment of insufficiency fractures in elderly patients. However, positioning of transpubic screw osteosynthesis is not always possible due to narrowness and curvature of the screw corridor. The aim of the present study was to evaluate availability and length of the screw corridor using a 3D statistical model of the pelvic ring consisting out of 150 uninjured pelves. Virtual bore probes with a diameter of 7.5 mm were analysed as to accessibility, length and grey value distribution in Hounsfield Unit (HU). A transpubic corridor with a diameter of ≥ 7.5 mm was available in 185 of 300 investigated superior pubic rami with mean screw length of 131.7 mm. Accessibility of the screw corridor was higher in males than in females. However, screw length showed no systematic differences between the sexes or ethnicities. Analysis of the grey value distribution demonstrated the strongest bone to be located at the lateral ilium and the supraacetabular region.

Does surgical treatment for unstable fragility fracture of the pelvis promote early mobilization and improve survival rate and postoperative clinical function?

PURPOSE

This retrospective multicenter study aimed to compare rates of early mobilization and survival and functional outcome of surgical treatment (S) with that of conservative treatment (C) according to each unstable fragility fracture of the pelvis (FFP) classification type with displacement of the posterior component ≥ 5 mm.

METHODS

We analyzed 64 patients with unstable type III and IV FFP who could move and transfer themselves before injury and had ≥ 5 mm displacement of the posterior component. We compared survival rate, early mobilization, walking ability at final follow-up, and complications at admission for each type of surgical and conservative treatment.

RESULTS

Most of the unstable FFP were type IIIa and IVb in the study population. Type III comprised 40 cases (group S:13/group C:27) and type IV comprised 24 cases (group S:7/group C:17). There were no significant differences in 3 month and 1 year survival rates, although group C (III) had the tendency of higher mortality rate (p = 0.08). Mobilization (transferring to a wheelchair) was enabled significantly earlier in group S (III) than in group C (III) (p = 0.02), but in type IV, most patients enabled early mobilization even without surgical intervention. There were no significant differences in hospital complications and walking ability at final follow-up.

CONCLUSION

In this study, the superiority of surgical treatment for unstable FFP was not proven. However, the results suggest that type IVb may be a relatively stable type compared to type III and that type IVb should be considered separately from bilaterally complete unstable sacral fractures due to high-energy trauma.

Differential diagnosis of acute traumatic hip pain in the elderly

Elderly patients who present with an inability to weight bear following a fall, with normal radiographs, should be appropriately investigated to rule out an occult hip fracture (OHF). We aim to identify both the range and incidence of the differential diagnosis of acute traumatic hip pain in a large series of patients investigated for OHF. A retrospective analysis of consecutive patients investigated for an OHF with magnetic resonance imaging (MRI) was performed. Dedicated musculo- skeletal radiologists reported the MRI scans. All diagnoses including hip fractures, other fractures and soft tissue injuries were recorded. Case notes were reviewed for all patients to identify subsequent complications, management and outcomes. A total of 157 patients fulfilled the inclusion criteria. 52 (33%) patients had a fracture of the proximal femur. The majority of patients with proximal femoral fractures required surgical intervention. 9 patients who had fractures of the greater trochanter of the femur without fracture extension across the femoral neck were managed non-operatively. 40 (25%) patients had fractures of the pelvis, with a combined pubic rami and sacral fracture occurring frequently. The most common diagnosis was a soft tissue injury alone that was seen in 60 (38%) patients imaged. Injuries to the gluteal muscle group, iliopsaos complex and trochanteric bursa were most prevalent. All patients with soft tissue injuries or fractures of the pelvis were successfully managed non-operatively. This study highlights a wide range of differential diagnoses in elderly patients presenting with acute traumatic hip pain. The proximal femur was frac- tured in 33% of patients imaged for OHFs in our series. The most common diagnosis was a soft tissue injury around the hip and pelvis ; these injuries can be successfully managed without surgery.

Current concepts: managing acetabular fractures in the elderly population

The aim of this review is to summarise the current concepts in the management of acetabular fractures in the elderly population. A literature review of the evidence regarding the management of elderly acetabular fractures was performed utilising PubMed and Ovid. The predominant causes and fracture patterns of acetabular fractures are changing as populations age. Consequently, the operative management has had to change also. Judet and LeTournel did not offer operative treatment to any patients older than sixty. However, in the present time, according to the German Pelvic Registry, over half the patients aged sixty or over, sustaining acetabular fractures underwent operative fixation. We find that the increasing age of the population raises particular challenges for the operating surgeon. Postoperative rehabilitation should be focused on early mobilisation. More research needs to be focussed on standardised treatment protocols and long-term outcomes for this cohort of patients.

Sacral fractures: An updated and comprehensive review

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

Surgical debridement of infected pubic symphysitis supports optimal outcome

INTRODUCTION

Infected pubic symphysitis (IPS) is a rare bacterial infection of the pubic symphysis that causes subpubic pain, disability and ultimately permanent immobility. Due to difficult diagnosis, patients present with long-standing complaints and consult several doctors. To date, no validated treatment protocol exists and most patients are treated conservatively with antibiotics. This study was aimed to assess the results after careful surgical debridement and pathogen-specific antibiotic treatment in IPS.

MATERIALS AND METHODS

A chart review of eight patients with proven IPS was performed. Five of eight patients filled in a specific own-developed questionnaire and could be examined clinically and radiologically at a mean of 13 months (range: 6-30 months) postoperatively.

RESULTS

There were six males and two females with an average age of 69 years (range: 55-80 years). The mean duration of symptoms before surgical treatment was 10.5 months (range: 1-30 months). There were no complications due to the surgical debridement. There was no recurrence of infection at the pubic symphysis during the follow-up period. The most common pathogen was Pseudomonas aeruginosa in three patients. Mean preoperative pain, measured on the visual analogue scale (VAS, range: 0-10) for the four analysed categories in the five follow-up patients was 7.2, 30 days postoperatively 2.7 and 13 months postoperatively 0.4. There was a steady increase in the quality of life (QoL) 30 days postoperatively and at the 13 months follow-up when compared to preoperative values.

CONCLUSIONS

Surgical debridement is the keystone for treatment of IPS and should be combined with local and systemic antibiotic therapy.

Secondary Angio-Embolization After Emergent Pelvic Stabilization and Pelvic Packing Is a Safe Option for Patients With Persistent Hemorrhage From Unstable Pelvic Ring Injuries

Introduction: In patients with severe pelvic ring injuries, exsanguination still is the leading cause of death in the early post-injury phase. While mechanical pelvic ring stabilization and pre-peritoneal pelvic packing are mainly addressing venous bleeding, angio-embolization aims to control arterial bleeding. The goal of the present study was to evaluate the rate of postoperative angio-embolization after mechanical pelvic ring injury stabilization and pre-peritoneal pelvic packing. Bleeding sources detected in the angiography and the patient's outcome were investigated.

Patients and Methods: Retrospective observational cohort study at a single academic level I trauma center, reviewing all patients with pelvic ring injuries admitted from 01/2010 to 12/2019. Patients with emergent mechanical pelvic ring stabilization (supraacetabular external fixator and/or pelvic C-clamp) and direct pre-peritoneal pelvic packing were further analyzed. Patients that underwent postoperative angio-embolization were compared with those that did not. All postoperative angio-embolizations were evaluated with regards to bleeding sources and type of embolization.

Results: During the study period, a total of 39 patients required immediate mechanical pelvic stabilization and direct pre-peritoneal pelvic packing. Of these, 12 patients (30.8%) underwent a postoperative angio-embolization. The following vessels were identified as bleeding sources: superior gluteal artery (n = 6), obturator artery (n = 2), internal pudendal artery (n = 2), unnamed branches of the internal iliac artery (n = 3). A selective embolization was successful in 11 patients; in 1 patient, an unilateral complete occlusion of the internal iliac artery was performed to control the bleeding. Mean time from hospital admission to the surgical procedure was 52.8 ± 14.7 min and the mean time from admission to angio-embolization was 189.1 ± 55.5 min. The in-hospital mortality rate of patients with angio-embolization was 25.0% (n = 3). Of these, 2 patients died due to multiple organ failure and 1 patient due to severe head injury.

Conclusion: Secondary angio-embolization after external pelvic fixation and pre-peritoneal pelvic packing was effective in controlling ongoing bleeding. The most frequently detected bleeding vessel was the superior gluteal artery, which is difficult to surgically address, further highlighting the importance of angio-embolization in the management algorithm.

Iliac intramedullary stabilization for Type IIIA fragility fractures of the pelvis

There have been few reports on fixation of Rommens classification Type IIIA fragility fractures of the pelvis (FFPs). Here, we present our less invasive surgical technique, called iliac intramedullary stabilization (ILIS), for the internal fixation of Type IIIA FFPs. The technique involves a closed reduction, termed the femur internal rotation reduction method (FIRM), whereby the fracture fragments are repositioned using lateral rotators by internally rotating the femur while the patient is in the prone position. Two iliac screws are inserted on the ilium bilaterally via the supra-acetabular bone canal during FIRM and connected with two transverse rods and two cross connectors. We refer to this internal fixation procedure as ILIS. We retrospectively recruited patients with Type IIIA fractures, treated using this procedure, at our institute between October 2017 and October 2019. We evaluated operative and post-operative outcomes. We enrolled 10 patients (9 women and 1 man; mean age, 85.2 years) who were followed up for over 6 months. All patients suffered FFPs after falling from a standing position. The mean operative time was 145.1 (range, 94–217) minutes, and the mean blood loss was 258.5 (range, 100–684) ml. All patients were allowed full weight bearing from post-operative day 1. All patients achieved bone union and regained their pre-injury walking ability at 6 months after surgery without evident secondary displacement. In conclusion, our ILIS technique allows less invasive internal fixation of Type IIIA FFPs with adequate stability for full weight bearing from post-operative day 1.

The diagnostic and management challenge for concomitant fragility fractures of pelvis and hip - a Case series with literature review

BACKGROUND

Fragility fractures of hip and pelvis in the elderly population are common. They do co-exist but are frequently missed and undertreated.

METHODS AND RESULTS

3 cases of concomitant fragility fractures of hip and pelvis were identified. Hip fractures were treated with cemented hemiarthroplasty or cephalomedullary nail fixation, while pelvic fractures were treated with percutaneous screw fixation in same general anesthesia session. Anti-osteoporotic treatments were offered. Subjects were followed up for 1 year.

CONCLUSION

Surgical treatment of fragility hip and pelvic fractures improves fracture stability, achieves better pain relief and allows earlier mobilization. Anti-osteoporotic treatment is essential as secondary prevention in fragility fractures.

The one-year mortality rate in elderly patients with osteoporotic fractures of the pelvis

Osteoporosis is a common condition for elderly people. The incidence of osteoporotic pelvic fractures has been increasing. Osteoporotic pelvic fractures are associated with increased mortality rates. Based on the aim of our study, we found out that one-year mortality rate after a pelvic fracture is high and depends on the fracture type.

PURPOSE

The aim of this study was to determine the one-year mortality rate in patients aged 65+ with osteoporotic pelvic fractures depending on the type of fracture according to AO/OTA classification.

METHODS

Patients aged 65+ with pelvic insufficiency fractures admitted to a single center between 1 June 2013 and 31 December 2016 were enrolled in the study. The fractures were classified according to AO/OTA classification. The start of the survival time analysis was the date of the injury. The end of the analysis was 31 December 2017 or the date of the patient's death. Mortality rates were assessed with respect to fracture types using Kaplan-Meier curves. The Cox proportional hazards model was applied to assess the dependence of mortality on the fracture type.

RESULTS

A total of 105 patients with 95 (90.5%) being female were enrolled in this prospective study. The average age was 80.3 years (95% CI 78.8-81.7). Mean follow-up time was 23.5 months (95% CI 20.7-26.4). According to AO/OTA classification, 30 (28.6%) patients had a type A pelvic fracture, 73 (69.5%) patients-type B fracture, and 2 (1.9%)-type C fracture. Overall, the one-year mortality rate was 23.8% (95% CI 16.8-33.2%). For patients with type A fracture, the one-year mortality rate was 13.3% (95% CI 5.2-31.7%) compared with 27.4% (95% CI 18.6-39.2%) in the group with type B fracture, and this difference was statistically significant (p < 0.001).

CONCLUSIONS

We found that within a year after an osteoporotic pelvic fracture, the number of deaths in the patients having type B pelvic fracture was twice higher than in the patients with type A fracture.

Early Operative Versus Nonoperative Treatment of Fragility Fractures of the Pelvis: A Propensity-Matched Multicenter Study

OBJECTIVE

To compare early operative treatment with nonoperative treatment of fragility fractures of the pelvis regarding mortality and functional outcome.

DESIGN

Retrospective.

SETTING

Two trauma centers.

PATIENTS AND METHODS

Two hundred thirty consecutive patients 60 years of age or older with an isolated low-energy fracture of the pelvis and with a follow-up of at least 24 months. In center 1, treatment consisted of a nonoperative attempt and early operative fixation if mobilization was not possible. In center 2, all patients were treated nonoperatively.

MAIN OUTCOME MEASUREMENTS

Primary outcome was mortality. Secondary outcomes were in-hospital complications. Patients who survived were contacted by phone, and a modified Majeed score was obtained to assess functional outcome at the final follow-up.

RESULTS

At the final follow-up (mean 61 months, SD 24), 105/230 (45.7%) patients had died. One year after the initial hospitalization, 34/148 patients [23%, 95% confidence interval (CI): 17%-31%] of the early operative group and 14/82 patients (17%, 95% CI: 10%-27%) of the nonoperative group had died (P = 0.294). Nonoperative treatment had a protective effect on survival during the first 2 years (hazard ratio of the nonlinear effect: 2.86, 95% CI: 1.38-5.94, P < 0.001). Patients in the early operative treatment group who survived the first 2 years had a better long-term survival. The functional outcome at the end of follow-up as measured by a modified Majeed score was not different between the 2 groups (early operative: 66.1, SD 12.6 vs. nonoperative: 65.7, SD 12.5, P = 0.910).

CONCLUSION

Early operative fixation of patients who cannot be mobilized within 3-5 days was associated with a higher mortality rate and complication rate at 1 year but with a better long-term survival after more than 2 years. Hence, patients with a life expectancy of less than 2 years may not benefit from surgery with regard to survival.

LEVEL OF EVIDENCE

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

Space available for trans-sacral implants to treat fractures of the pelvis assessed by virtual implant positioning

INTRODUCTION

The use of trans-sacral implants to treat fractures of the sacrum is limited by the variable pelvic anatomy. We were interested in how many trans-sacral implants can be placed per pelvis? If a trans-sacral implant cannot be placed in S1, where is the cortex perforated, and is the use of sacroiliac screws safe in these pelves?

MATERIALS AND METHODS

3D pelvic models were created from CT scans of 156 individuals without fractures (92 European and 64 Japanese, 79 male and 77 female, mean age 66.7 ± 13.7 years). Trans-sacral implants with a diameter of 7.3 mm were positioned virtually with and without a surrounding safe zone of 12 mm diameter.

RESULTS

Fifty-one percent of pelves accommodated trans-sacral implants in S1 with a safe zone. Twenty-two percent did not offer enough space in S1 for an implant even when ignoring the safe zone. Every pelvis had sufficient space for a trans-sacral implant in S2, in 78% including a safe zone as well. In S1, implant perforation was observed in the sacral ala and iliac fossa in 69%, isolated iliac fossa perforation in 23% and perforation of the sacral ala in 8%. Bilateral sacroiliac screw placement was always possible in S1.

CONCLUSIONS

The use of trans-sacral implants in S1 requires meticulous preoperative planning to avoid injury of neurovascular structures. S2 more consistently offers space for trans-sacral implants.

Intramedullary Stabilization of Pubic Ramus Fractures in Elderly Patients With a Photodynamic Bone Stabilization System (IlluminOss)

Introduction:

A photodynamic bone stabilization system (PBSS) is a percutaneous operating method that provides intramedullary stabilization. The purpose of the study was to assess the clinical and radiological outcome after treatment of pubic ramus fractures with the PBSS.

Materials and Methods:

In a retrospective study, patients with osteoporotic pubic ramus fractures were included. The patients were treated with the PBSS in a percutaneous method. In the routine follow-up examination, pain was measured with the visual analog scale (VAS) and the type of mobilization was verified. Computer tomography of the pelvis was carried out in the follow-up examination (mean of 7.5 months after surgery) to investigate bone healing.

Results:

A total of 32 patients (25 females and 7 males) were included in the study. The average hospital stay was 16.5 ± 7.9 days (range: 5-37 days) and the mean operation time was 116.8 ± 47.1 minutes (range: 33-255 minutes). Two cases of wound infections and 1 case of misplacement of the PBSS implant with revision surgery have been documented. The mean VAS score for pelvic/hip pain at the day of inpatient discharge was 4.4 ± 1.4 (range: 2-7). A total of 25 patients could attend the follow-up examination 7.5 ± 1.7 months (range: 6-14) after the procedure, reporting a mean VAS for pelvic/hip pain of 3.0 ± 2.2 (range: 0-8). A total of 11 patients could walk without an orthopedic walking device, 7 patients needed underarm crutches, 6 patients used a walker-rollator, and 1 patient was immobilized. Consolidated pubis ramus fractures were described in 24 (96%) cases.

Discussion:

The results of our study reveal adequate clinical and radiological outcomes after treatment of osteoporotic pubic ramus fractures with the PBSS. This is the first study investigating the outcome after treating pubic ramus fractures with the PBSS.

Conclusion:

Based on our findings, the PBSS is an alternative to known techniques for the stabilization of the pubic ramus.

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.

Short-term follow-up of anterior and posterior both column fractures of acetabulum managed through both column plating

OBJECTIVE

To evaluate the results of short-term follow-up of patients of both column acetabular fractures managed through anterior and posterior column plating.

INTRODUCTION

Both column acetabular fractures are challenging articular injuries. Majority of them are treated operatively. The concept of "secondary congruence" was introduced by Letournel. Despite this, biomechanical data on secondary congruence indicate that nonoperative treatment leads to an increase in peak pressures in the supraacetabular region with the potential risk of developing posttraumatic degenerative osteoarthritis. Operative management is therefore justified.

METHODOLOGY

A cohort of 10 patients having both column (anterior and posterior) acetabular fractures managed using bicolumnar plating between January 2016 and December 2017 were enrolled in the study and were analyzed during follow-up period.

RESULTS

In total, 80% of the patients had excellent to good result. Average postoperative score was 85.7. Assessment was done using modified Harris Hip score.

Posterior pelvic ring fractures: Intraoperative 3D-CT guided navigation for accurate positioning of sacro-iliac screws

INTRODUCTION

Posterior pelvic ring fractures frequently pose a problem of stability with an elevated risk of complications. The traditional method of percutaneous sacroiliac (SI) stabilization with the use of fluoroscopic image amplifiers demands a high degree of experience and has an elevated risk of screws' malpositioning.

HYPOTHESIS

Intraoperative 3D-CT scan coupled with a navigation system (O-Arm^©) can allow screw fixation accuracy while limiting the risk of complications for the treatment of posterior pelvic ring fractures.

MATERIAL AND METHODS

Patients with posterior pelvic ring fractures stabilized with percutaneous SI screws through O-Arm^© navigation from August 2008 to December 2017 were analyzed. A modified Gras classification was used to determine screws' positioning under CT visualization, and intraoperative and early postoperative complications were documented.

RESULTS

Among the 21 patients evaluated, 14 men and 7 women with a mean age of 57.8 years (range 25-91), receiving 39 screws, the rate of misplacement was low: 82% grade I, 15.4% grade II, and only 2.6% grade III. Only one patient underwent revision surgery, not because of misplacement but rather for a secondary implant loosening. No complications occurred in this series.

DISCUSSION

This study documented a large series of patients treated for pelvic ring fractures using the intraoperative 3D-CT O-Arm^© guided navigation. This surgical approach provided a precise and safe SI screw positioning with no complications.

LEVEL OF EVIDENCE

IV, Retrospective study.

Mid-term follow-up after surgical treatment of fragility fractures of the pelvis

INTRODUCTION

Early operative treatment of fragility fractures of the pelvis (FFP) has been suggested to reduce pain and allow for earlier mobilization. The aim of this study was to determine mortality and functional outcome after operative treatment.

PATIENTS AND METHODS

Patients aged ≥60 years (n = 60; mean age 79 years, 53 female) who had operative treatment of a FFP and a follow-up of at least 2 years were identified and mortality was assessed using a national social insurance database. Those who had survived were contacted by phone and a modified Majeed Score was obtained.

RESULTS

At final follow up (62 months, range, 29-117), 32 patients (53.3%) had deceased. One-year-mortality rate was 28.3% and 2-year mortality was 36.7%. Mortality was not linked to fracture type (p > .05). Complications during hospitalization occurred in 26/60 patients (43.3%). Patients with a bilateral FFP had a longer hospitalization (18 vs. 11 days; p = .021). The mean modified Majeed score of surviving patients was 65 points (85.5% of achievable maximum).

CONCLUSION

Mortality and in-hospital complications remain high among patients with FFP even when treated operatively. A longer hospitalization can be expected in patients with posterior bilateral fractures.

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.

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).

Sacral Insufficiency Fractures : How to Classify?

Objective

The diagnosis of insufficiency fractures of the sacrum in an elder population increases annually. Fractures show very different morphology. We aimed to classify sacral insufficiency fractures according to the position of cortical break and possible need for intervention.

Methods

Between January 1, 2008 and December 31, 2014, all patients with a proven fracture of the sacrum following a low-energy or an even unnoticed trauma were prospectively registered : 117 females and 13 males. All patients had a computer tomography of the pelvic ring, two patients had a magnetic resonance imaging additionally : localization and involvement of the fracture lines into the sacroiliac joint, neural foramina or the spinal canal were identified.

Results

Patients were aged between 46 and 98 years (mean, 79.8 years). Seventy-seven patients had an unilateral fracture of the sacral ala, 41 bilateral ala fractures and 12 patients showed a fracture of the sacral corpus : a total of 171 fractures were analyzed. The first group A included fractures of the sacral ala which were assessed to have no or less mechanical importance (n=53) : fractures with no cortical disruption (“bone bruise”) (A1; n=2), cortical deformation of the anterior cortical bone (A2; n=4), and fracture of the anterolateral rim of ala (A3; n=47). Complete fractures of the sacral ala (B; n=106) : parallel to the sacroiliac joint (B1; n=63), into the sacroiliac joint (B2; n=19), and involvement of the sacral foramina respectively the spinal canal (B3; n=24). Central fractures involving the sacral corpus (C; n=12) : fracture limited to the corpus or finishing into one ala (C1; n=3), unidirectional including the neural foramina or the spinal canal or both (C2; n=2), and horizontal fractures of the corpus with bilateral sagittal completion (C3; n=8). Sixty-eight fractures proceeded into the sacroiliac joint, 34 fractures showed an injury of foramina or canal.

Conclusion

The new classification allowes the differentiation of fractures of less mechanical importance and a risk assessment for possible polymethyl methacrylate leaks during sacroplasty in the direction of the neurological structures. In addition, identification of instable fractures in need for laminectomy and surgical stabilization is possible.

Critical dimensions of trans-sacral corridors assessed by 3D CT models: Relevance for implant positioning in fractures of the sacrum

Trans-sacral implants can be used alternatively to sacro-iliac screws in the treatment of osteoporosis-associated fragility fractures of the pelvis and the sacrum. We investigated trans-sacral corridor dimensions, the number of individuals amenable to trans-sacral fixation, as well as the osseous boundaries and shape of the S1 corridor. 3D models were reconstructed from pelvic CT scans from 92 Europeans and 64 Japanese. A corridor of <12 mm was considered critical for trans-sacral implant positioning, and <8 mm as impossible. A statistical model of trans-sacral corridor S1 was computed. The limiting cranio-caudal diameter was 11.6 mm (±5.4) for S1 and 14 mm (±2.4) for S2. Trans-sacral implant positioning was critical in 52% of cases for S1, and in 21% for S2. The S1 corridor was impossible in 26%, with no impossible corridor in S2. Antero-superiorly, the S1 corridor was limited not only by the sacrum but in 40% by the iliac fossa. The statistical model demonstrated a consistent oval shape of the trans-section of corridor S1. Considering the variable in size and shape of trans-sacral corridors in S1, a thorough anatomical knowledge and preoperative planning are mandatory using trans-sacral implants. In critical cases, S2 is a veritable alternative. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2577-2584, 2017.

Implementation of a standardized protocol to manage elderly patients with low energy pelvic fractures: can service improvement be expected?

PURPOSE

The incidence of low energy pelvic fractures (FPFs) in the elderly is increasing. Comorbidities, decreased bone-quality, problematic fracture fixation and poor compliance represent some of their specific difficulties. In the absence of uniform management, a standard operating procedure (SOP) was introduced to our unit, aiming to improve the quality of services provided to these patients.

METHODS

A cohort study was contacted to test the impact of (1) using a specific clinical algorithm and (2) using different antiosteoporotic drugs. Multivariate regression analysis was used to determine prognostic factors. Study endpoints were the time-to-healing, length-of-stay, return to pre-injury mobility, union status, mortality and complications.

RESULTS

A total of 132 elderly patients (≥65 years) admitted during the period 2012-2014 with FPFs were enrolled. High-energy fractures, acetabular fractures, associated trauma affecting mobility, pathological pelvic lesions and operated FPFs were used as exclusion criteria. The majority of included patients were females (108/132; 81.8%), and the mean age was 85.8 years (range 67-108). Use of antiosteoporotics was associated with a shorter time of healing (p = 0.036). Patients treated according to the algorithm showed a significant protection against malunion (p < 0.001). Also, adherence to the algorithm allowed more patients to return to their pre-injury mobility status (p = 0.039).

CONCLUSIONS

The use of antiosteoporotic medication in elderly patients with fragility pelvic fractures was associated with faster healing, whilst the adherence to a structured clinical pathway led to less malunions and non-unions and return to pre-injury mobility state.

Biomechanical comparison of augmented versus non-augmented sacroiliac screws in a novel hemi-pelvis test model

Operative treatment of sacral insufficiency fractures is frequently being complicated by osteopenic bone properties. Cement augmentation of implanted sacroiliac screws may lead to superior construct stability and prevent mechanical complications. A novel hemi-pelvis test model with dissected symphysis was developed. Five fresh-frozen cadaveric pelvises were vertically osteotomized at the sacrum on both sides and fixed with sacroiliac screws in both corridors of the first sacral vertebral body. One side was randomly augmented with bone cement. Cyclic testing consisting of torsional loading (±2.5 Nm) combined with progressively increasing axial loading (+50 N compression, -10 N traction, ±0,01 N/cycle) was performed until failure; simulated physiological loads derived from inverse dynamic calculations. The fixation was analyzed fluoroscopically quantifying screw migrations and assessing failure mechanisms. Failure modes were cut-out, pull-out, screw-out, and washer penetration. Motion at fracture site was analyzed via optical motion tracking. Unscrewing was provoked four times with non-augmented and twice with augmented screws. When focusing on the sacral region only, cement augmentation significantly improved screw fixation in terms of increased number of cycles to failure (p = 0.043). However, when considering overall construct stability, there was no significant difference between augmented and non-augmented state due to washer penetration at the iliac bone. The generated hemi-pelvis model was found to be valid due to the reproduction of the clinically observed failure mode (unscrewing). Unscrewing was not fully prevented by cement augmentation. Augmentation effects stability at the screw tip, but particularly in porotic bone, failure may shift to the next weak point. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1485-1493, 2017.

Identification of potential target genes and related regulatory transcription factors in spontaneous hairline fracture induced by hypervitaminosis A

BACKGROUND

The aim was to research the molecular changes of bone cells induced by excessive dose of vitamin A, and analyze molecular mechanism underlying spontaneous fracture.

METHODS

The gene expression profile of GSE29859, including 4 cortical bone marrow samples with excessive doses of Vitamin A and 4 control cortical bone marrow samples, was obtained from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DGEs) between cortical bone marrow samples and control samples were screened out and pathway enrichment analysis was undertaken. Based on the MSigDB database, the potential regulatory transcription factors (TFs) were identified.

RESULTS

A total of 373 DEGs including 342 up- and 31 down-regulated genes were identified. These DEGs were significantly enriched in pathways of protein processing in endoplasmic reticulum, ubiquitin mediated proteolysis and glycerophospholipid metabolism. Finally, the most significant regulatory TFs were obtained, including E2F Transcription Factor 1 (E2F1), GA Binding Protein Transcription Factor (GABP), Nuclear Factor, Erythroid 2-Like 2 (NRF2) and ELK1, Member of ETS Oncogene Family (ELK1).

CONCLUSION

Key TFs including E2F1, GABP, NRF2 and ELK1 and their targets genes such as Ube2d3, Uba1, Phb2 and Tomm22 may play potential key roles in spontaneous fracture induced by hypervitaminosis A. The pathways of protein processing in endoplasmic reticulum, ubiquitin mediated proteolysis and glycerophospholipid metabolism may be key mechanisms involved in spontaneous fracture induced by hypervitaminosis A. Our findings will provide new insights for the target selection in clinical application to prevent spontaneous fracture induced by hypervitaminosis A.

Pelvic fractures: epidemiology, consequences, and medical management

PURPOSE OF REVIEW

Until recently, osteoporotic pelvic fractures have not been specifically studied. This review presents an update on epidemiological data of pelvic fracture, including morbidity, mortality and healthcare costs, the role of surgery and new data on sacroplasty in acute phase management.

RECENT FINDINGS

All studies underline the burden of osteoporotic pelvic fractures. Risk factors associated with these fractures are age, sex (women), and previous loss of autonomy. An increased mortality has been reported in all publications, similar to hip fracture for in-patient mortality and at 5 years of follow-up. Pelvic fractures often lead to transient or permanent autonomy loss, reflecting the high costs because of extended hospital stay, combined with nursing home requirement. However, recent studies report a decrease in the length of stay. Sacroplasty displays promising results to control pain and improve functional outcome. Early surgery begins to be discussed to also improve the outcome.

SUMMARY

Pelvic fractures display all the features of severe osteoporotic fractures: increased incidence, high morbidity, mortality, and healthcare costs that justify awareness of the practitioner on these fractures. Further studies on sacroplasty and surgery are necessary to improve pain control, functional improvement, thereby reducing the length of hospital stay and cost.

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.

Primary stability of three different iliosacral screw fixation techniques in osteoporotic cadaver specimens-a biomechanical investigation

BACKGROUND

The incidence of osteoporotic and insufficiency fractures of the pelvic ring is increasing. Closed reduction and percutaneous fixation with cannulated sacroiliac screws is well-established in the operative treatment of osteoporotic posterior pelvic ring fractures. However, osteoporotic bone quality might lead to the risk of screw loosening. For this reason, cement augmentation of the iliosacral screws is more frequently performed and recommended.

PURPOSE

The aim of the present biomechanical study was to evaluate the primary stability of three methods of iliosacral screw fixation in human osteoporotic sacrum specimens.

STUDY DESIGN/SETTING

This study used methodical cadaver study.

METHODS

A total of 15 fresh frozen human cadaveric specimens with osteoporosis were used (os sacrum). After matched pair randomization regarding bone quality (T-score), three operation technique groups were generated: screw fixation (cannulated screws) without cement augmentation (Group A); screw fixation with cement augmentation before screw placement (cannulated screws) (Group B); and screw fixation with perforated screws and cement augmentation after screw placement (Group C). In all specimens both sides of the os sacrum were used for operative treatment, resulting in a group size of 10 specimens per group. One operation technique was used on each side of the sacral bone to compare biomechanical properties in the same bone quality. Pull-out tests were performed with a rate of 6 mm/min. A load versus displacement curve was generated.

RESULTS

Subgroup 1 (Group A vs. Group B): Screw fixation without cement augmentation: 594.4 N±463.7 and screw fixation with cement augmentation before screw placement: 1,020.8 N±333.3; values were significantly different (p=.025). Subgroup 2 (Group A vs. Group C): Screw fixation without cement augmentation: 641.8 N±242.0 and perforated screw fixation with cement augmentation after screw placement: 1,029.6 N±326.5; values were significantly different (p=.048). Subgroup 3 (Group B vs. Group C): Screw fixation with cement augmentation before screw placement: 804.0 N±515.3 and perforated screw fixation with cement augmentation after screw placement: 889.8 N±503.3; values were not significantly different (p=.472).

CONCLUSIONS

Regarding iliosacral screw fixation in osteoporotic bone, the primary stability of techniques involving cement augmentation is significantly higher compared with screw fixation without cement augmentation. Perforated screws with the same primary stability as that of conventional screw fixation in combination with cement augmentation might be a promising alternative in reducing complications of cement leakage. These biomechanical results have to be transferred into clinical practice and prove their clinical value.