Fragility Fractures of the Pelvis Classification: A Multicenter Assessment of the Intra-Rater and Inter-Rater Reliabilities and Percentage of Agreement

Mayo classification of olecranon fractures revisited - Assessment of intra- and interobserver reliability based on CT scans

Purpose

Olecranon fractures are classified using the commonly accepted Mayo classification. Its reliability has been analyzed by means of radiographs. A CT scan is often obtained due to joint involvement. Purpose of this study was to evaluate the intra- and interobserver reliability of the Mayo classification based on CT examination.

Methods

Radiographic and CT images of 20 olecranon fractures were classified by four surgeons at two time points 30 days apart. Intra- and interobserver reliability were assessed using kappa coefficients.

Results

Mean intraobserver reliability between X-rays was substantial and between CTs almost perfect (0.76 and 0.82, respectively). Mean interobserver reliability was fair for X-rays and moderate for CTs (0.32 and 0.44, respectively).

Conclusion

Despite the more detailed imaging compared with radiography only moderate interobserver reliability was found for the classification of olecranon fractures based on CT imaging. This might lead to inconsistent fracture classification in both scientific and clinical setting.

Evaluation of a treatment protocol based on conservative therapy for fragility fractures of the pelvis

PURPOSE

In an aging society, fragility fractures of the pelvis (FFP) have increased significantly. However, there is no clear consensus on the timing and criteria for transitioning from conservative treatment to surgery for these fractures. Thus, we aimed to investigate the effects of our treatment protocol for FFP based on conservative treatment.

METHODS

We conducted a retrospective study including 74 patients with FFP at our institution between 2015 and 2021. All patients were treated conservatively for the first two weeks. During this period, only wheelchair transfer was allowed. If the patient could not walk after this period, surgery was performed. Fracture type (Rommens classification), walking ability, presence of complications after admission, presence of fracture union, and surgical treatment was investigated. Patients were divided into two groups: a stable group (type I/II) and an unstable group (type III/IV).

RESULTS

Fracture union was achieved in all patients. Thirteen patients developed complications after being admitted to our hospital; seven showed decreased walking ability, and six required surgeries. The stable and unstable groups comprised 47 and 27 patients, respectively. There were no statistically significant differences between the groups regarding the percentage of patients who developed complications or experienced decrease in walking ability. The percentage of patients who required surgery was significantly higher in the unstable group (p < 0.05).

CONCLUSION

Our FFP management protocol was effective regardless of fracture type. It is important to provide a period for careful assessment of instability, and to try to prevent fracture progression.

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

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

Proposal and validation of a new classification for trochanteric fractures based on medial buttress and lateral cortical integrity

Background

Trochanteric fractures usually require surgical treatment. The currently used classification system, such as AO classification, cannot cover all variant types, and is poor in reliability, causing confusion in surgical decision making. This study describes a simple, well-covered, re-liable, accurate, and clinically useful classification.

Methods

We retrospectively reviewed the records of 907 patients with trochanteric fractures treated by us from 1,999 to 2019 and proposed a new classification according to radiographs. Then, 50 records randomly selected in proportion were examined by 10 observers (5 experienced and 5 inexperienced) independently according to AO and the new classification. After a 2-week interval, repeat evaluation was completed. The Kappa coefficient was used to investigate the intra-observer reliability, inter-observer reliability and the agreement between the observers and the "reference standard".

Results

The new classification system includes 12 types composed of 3 medial groups and 4 lateral groups. According to the medial buttress, the fractures are divided into group I (intact lesser trochanter, adequate but-tress), group II (incomplete lesser trochanter, effective cortical buttress after reduction) and group III (huge defect of the medial cortex). According to the penetration region of the lateral fracture line, the fractures are divided into group A (intact lateral cortex), group B (incomplete lateral cortex), group C (subtrochanteric fractures) and group D (multiple lateral fracture lines). All of the included cases can be classified according to the new classification, of which 34 (3.75%) cases are unclassifiable by the AO classification. Intra-observer: The experienced achieved substantial agreement using both AO [k = 0.61 (95% confidence interval 0.46-0.76)] and new classification [k = 0.65 (0.55-0.76)]. The inexperienced reached moderate agreement using both AO [k = 0.48 (0.33-0.62)] and new classification [k = 0.60 (0.50-0.71)]. Inter-observer: The overall reliabilities for AO [k = 0.51 (0.49-0.53)] and for new classification [k = 0.57 (0.55-0.58)] were both moderate. The agreement between the experienced and the reference standard according to AO [k = 0.61 (0.49-0.74)] and new classification [k = 0.63 (0.54-0.72)] were both substantial. The agreement between the inexperienced and the reference standard according to AO [k = 0.48 (0.45-0.50)] and the new classification [k = 0.48 (0.41-0.54)] were both moderate.

Conclusion

Compared with AO classification, our new classification is better in coverage, reliability and accuracy, and has the feasibility of clinical verification and promotion.

Fragility Fractures of the Pelvis: Current Practices and Future Directions

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

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

Introduction

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

Methods

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

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

Results

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

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

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

Conclusion

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

Supplementary Information

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

Demographic changes in pelvic fracture patterns at a Swiss academic trauma center from 2007 to 2017

BACKGROUND

Increasing life expectancy has led to higher incidence of fragility fractures of the pelvis. These demographic changes may have a direct impact on fracture patterns. The goal of this study was (1) to evaluate demographical trends in patients with pelvic ring injuries at a tertiary Swiss trauma center and (2) to analyze the influence on fracture patterns.

METHODS

We performed a retrospective cross-sectional study including 958 patients (mean ± SD age, 57 ± 21 years; 48% women) with a pelvic ring injury between 2007 and 2017. Fractures were classified according to Tile, Young and Burgess or Rommens and Hofmann (fragility fractures) using conventional and computer tomography imaging. Low-energy fractures were defined as fractures resulting from fall from standing height or less. Fracture classifications, age, sex, Injury Severity Score, and trauma mechanism were compared using analysis of variance or χ2 test. Cluster analysis was performed to identify groups with similarities in fracture patterns and demographic parameters.

RESULTS

From 2007 to 2017, the frequency of pelvic ring injuries increased by 115% (increase per decade), and mean age increased by 15% (p = 0.031). A trimodal age distribution was found; highest increase for fractures occurred in the older (265%) patient group. Low-energy fracture was the most common trauma mechanism (43% of all fractures, an increase of 249%). Changes in fracture pattern showed a disproportioned increase of lateral compression (LC) fractures (LC type 1 in 64%) or partially stable fracture (B2, with 39%). In patient older than 65 years, the strongest increase was found for nondisplaced posterior fractures with an overall prevalence of 62%. Five clusters were found with the most frequent cluster representing older female patients with low-energy fracture (LC, Tile type B) in 30%.

CONCLUSION

The current results corroborate the trend of increasing frequency of fragility fractures in an aging society. The demographic shift has a direct impact on fracture pattern with a disproportionate increase in partially stable compression fracture of the pelvis.

LEVEL OF EVIDENCE

Prognostic/Epidemiologic, Level III.

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

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

Prospective assessment of key factors influencing treatment strategy and outcome of fragility fractures of the pelvis (FFP)

BACKGROUND

Fragility fractures of the pelvis (FFP) are a clinical entity with an increasing significance in clinical practice. Little is known about the conditions, which influence decision making and outcome.

SETTING

Level I trauma center.

MATERIAL AND METHODS

Prospective assessment of selected parameters of patients, who were admitted with a FFP in a 2-year period. Fractures were classified in accordance with the Rommens and Hofmann classification. Living environment, level of autonomy (independent walking), type of treatment (conservative versus operative), type of surgical technique, European Quality of Life-5 Dimensions-5 Levels (EQ-5D-5L), Short Form-8 Physical Component Score (SF-8 PCS) and Short Form-8 Mental Component Score (SF-8 MCS), Barthel Index, Parker Mobility Score (PMS) and Numeric Rating Scale (NRS) were collected at primary presentation (t1), at discharge (t2) and after 3 (t3) and 12 months (t4). Length of hospital stay, in-hospital complications, surgery-related complications, new osteoporotic fractures and mortality rate within the first year were also registered. The key factors influencing the choice of therapy and outcome were looked for.

RESULTS

110 patients, 99 women (90%) and 11 men (10%), were included in the study. Their mean age was 79.2 years (SD 10 years). Fourteen patients had FFP type I (12.7%), 59 FFP type II (53.6%), 11 FFP type III (10%) and 26 FFP type IV fractures (23.6%). All patients with FFP type I were treated conservatively. 48 patients with FFP types II-IV were treated conservatively and 48 operatively. Patients, who got a conservative outpatient treatment first and were hospitalized later, had higher FFP fracture types at admission. Operatively treated patients were hospitalized at a median of 33.5 days after the beginning of complaints, whereas the median day of admission of the conservative group was the day of trauma (p < 0.001). The operatively treated patients were hospitalized in a worse clinical condition (SF-8 PCS, EQ-5D-5L, autonomy). Length of stay (LoS) of operatively treated patients was significantly longer than of conservatively treated (p < 0.001). There was a tendency to more in-hospital complications in the operative group (p = 0.059). The rate of surgery-related complications (8.3%) was low with only one revision needed. Selected outcome parameters improved during the observation period nearly reaching the level before FFP after 1 year. SF-8 PCS, Barthel index and rate of patients living home were higher in the operative group at t4. The improvement of autonomy (independent walking) between t1 and t4 was significant in the operated group (p = 0.04) but not in the conservative group (p = 0.96). One-year mortality rate was 11.7% with no difference between the fracture types. One-year mortality rate of conservatively treated patients with FFP type II-IV was 13.5% versus 6.9% in the operative group (p = 0.38).

CONCLUSION

Conservative treatment is appropriate in patients with FFP type I as well as in patients with FFP type II, provided that the last ones are hospitalized immediately after the traumatic event. Surgical treatment is recommended in patients with higher fracture types, with delayed presentation or after unsuccessful conservative treatment. In the conservative and operative group, all selected parameters considerably improved between t1 and t4 with a steeper increase in the operative group. The rate of postoperative complications is low. The 1-year mortality rate is the lowest in the operative group. Surgical stabilization of FFP is safe and reliable provided it is performed with care and in the appropriate target group.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

OF-Pelvis classification of osteoporotic sacral and pelvic ring fractures

Objectives

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

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

Methods

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

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

Results

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

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

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

Conclusion

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

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.

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.

[Reliability of the FFP classification in pelvic fractures]

BACKGROUND

Pelvic fractures are typical for frail geriatric patients. They are characterized by increasing pain and loss of mobility. As geriatric pelvic fractures differ from the typical high velocity injuries, Rommens and Hofmann recommended a new classification for fragility fractures of the pelvis (FFP) in 2013. In addition to the location of the fracture they also assessed the degree of dislocation.

OBJECTIVE

Compared to known fracture classifications of the pelvis, the FFP classification appears complex. Therefore, this study was designed to investigate the interobserver reliability of the FFP classification.

MATERIAL AND METHODS

The members of the Section of Geriatric Traumatology (DGOU) were presented with 10 DICOM data sets with fractures of the pelvis for classification. As a reference the classification of P.M. Rommens, the author of the FFP, was established.

RESULTS

In this study 24 consultants (47%) and 27 (53%) residents took part. Also, six radiologists were invited to participate. A total of 493 assessments were made. In 184 (37%) cases there was agreement with the reference, in 183 (37%) computed tomography images the fractures were classified lower, in 26 (26%) higher than the reference. This initially resulted in a Cohens κ coefficient of 0.36. This corresponds to a sufficient agreement (fair) according to Garbuz. With the reduction of the classification to four main groups, the Cohens κ coefficient increased to a satisfactory value.

CONCLUSION

The reasons for the partly low agreement could be the participants' lack of experience and an inaccurate description of the classification levels. In the end, however, the FFP classification is the only one that meaningfully represents pelvic fractures of geriatric and frail patients. By simplifying to the four main groups, a better interobserver reliability is achieved. For a successful treatment, however, attention to the individual patient and the "fracture personality" is essential.

An alphanumeric classification of osteoporotic pelvic ring injuries

INTRODUCTION

Classification and management of osteoporotic pelvic ring injuries (OPRI) continue to pose a considerable challenge to orthopaedic traumatologists. The currently used fragility fractures of the pelvis (FFP) classification of OPRI has recently been shown to have significant weaknesses. The aim of this study therefore was to propose a new, simple, yet comprehensive alphanumeric classification (ANC) of OPRI and to assess its intra- and interobserver reliability. Furthermore, its potential advantages over the FFP classification are discussed.

MATERIALS AND METHODS

One hundred consecutive CT scans from patients with OPRI were evaluated by three orthopaedic traumatologists with varying levels of experience and one musculoskeletal radiologist. Intra- and interobserver reliability of the proposed classification system was assessed using weighted kappa (κ) statistics and percentage agreement. In addition, the Fleiss' kappa statistic was computed to assess interobserver agreement among all four raters.

RESULTS

Overall intraobserver reliability of the proposed ANC was substantial [κ ranging from 0.71 to 0.80; percentage agreement: 70% (range, 67-76%)]. Overall interobserver reliability between pairs of raters was substantial as well [κ ranging from 0.61 to 0.68; percentage agreement: 58% (range, 53-61%)]. For ANC types, groups and subgroups, intra- and interobserver reliability were substantial to almost perfect. Interobserver agreement among all four raters was moderate to substantial, with Fleiss' kappa values of 0.48, 0.69, 0.71 and 0.52 for ANC overall, types, groups and subgroups, respectively.

CONCLUSION

The proposed ANC of OPRI demonstrated overall reliability comparable to that of the FFP classification. The ANC, however, is simple, more comprehensive, and consistently relates to injury severity.

Safety, Effect and Feasibility of Percutaneous SI-Screw with and without Augmentation-A 15-Year Retrospective Analysis on over 640 Screws

BACKGROUND

Minimally invasive sacroiliac-screw (SI-screw) fixation of the pelvis is used in energy trauma (Arbeitsgemeinschaft für Osteosynthesefragen (AO) classified) and fragility fractures (Fragility Fracture of the Pelvis (FFP) classified). However, available clinical data are based on small case series and biomechanical data seem to be contradictory.

METHODS

The present single center retrospective cohort study investigated percutaneous SI-screw fixation and augmentation over 15 years. Groups were compared concerning the general epidemiological data, mobilization, complication rates, duration of stay, and safety of SI-screw insertion. Multivariable analyses were performed using logistic regression.

RESULTS

Between 2005 and March 2020, 448 patients with 642 inserted SI-screws were identified. Iatrogenic neurological impairment was documented in 2.47% and correlated with screw misplacement. There was an increased complication risk in patients with AO type C over patients with AO type B and in FFP II over FFP III/IV patients. Cement-augmented FFP patients showed a 25% reduced stay in hospital and a reduced complication risk. Cement-associated complications were seen in 22% without correlation to neurologic impairment.

CONCLUSIONS

The present study confirms the safety and usability of percutaneous SI-screw fixation, despite specific risks. Cement augmentation seems to reduce the complication risk in FFP patients and shorten hospital stay for some reasons, without increased specific complications or correlated neurological impairment.

Risks and Strategies to Avoid Approach-Related Complications During Operative Treatment of Pelvic Ring or Acetabular Fractures

Injuries of the pelvic ring or the acetabulum are either to be found in young patients with high energy trauma mechanisms or in geriatric patients after simple falls with very low impact energy. The indication for surgical stabilization is given by the grade of instability. Exact knowledge of the different possible surgical approaches is essential for the planning of the surgical treatment. Both, knowledge of reachable anatomical structures and possible risks of the different approaches are important. In this review, we summarize the standard surgical approaches to the pelvic ring and to the acetabulum. We describe the reachable anatomical structures for each approach, approach-related pitfalls, and we focus on strategies to reduce approach-related complications.