Progressive instability of bilateral sacral fragility fractures in osteoporotic bone: a retrospective analysis of X-ray, CT, and MRI datasets from 78 cases

Chronic pelvic insufficiency fractures and their treatment

Fragility and insufficiency fractures of the pelvis (FFP) and sacrum (SIF) are increasingly prevalent, particularly among the elderly, due to weakened bone structure and low-energy trauma. Chronic instability from these fractures causes persistent pain, limited mobility, and significant reductions in quality of life. Hospitalization is often required, with substantial risks of loss of independence (64-89%) and high mortality rates (13-27%). While conservative treatment is possible, surgical intervention is preferred for unstable or progressive fractures. FFP and SIF are primarily associated with osteoporosis, with 71% of patients not receiving adequate secondary fracture prevention. Imaging modalities play a crucial role in diagnosis. Conventional radiography often misses sacral fractures, while computed tomography (CT) is the gold standard for evaluating fracture morphology. Magnetic resonance imaging (MRI) offers the highest sensitivity (99%), essential for detecting complex fractures and assessing bone edema. Advanced techniques like dual-energy CT and SPECT/CT provide further diagnostic value. Rommens and Hofmann's classification system categorizes FFP based on anterior and posterior pelvic ring involvement, guiding treatment strategies. Progression from stable fractures (FFP I-II) to highly unstable patterns (FFP IV) is common and influenced by factors like pelvic morphology, bone density, and sarcopenia. Treatment varies based on fracture type and stability. Non-displaced posterior fractures can be managed with sacroplasty or screw fixation, while displaced or unstable patterns often require more invasive methods, such as triangular lumbopelvic fixation or transsacral bar osteosynthesis. Sacroplasty provides significant pain relief but has limited stabilizing capacity, while screw augmentation with polymethylmethacrylate improves fixation in osteoporotic bones. Anterior ring fractures may be treated with retrograde transpubic screws or symphyseal plating, with biomechanical stability and long-term outcomes depending on fixation techniques. FFP and SIF management requires a multidisciplinary approach to ensure stability, pain relief, and functional recovery, emphasizing early diagnosis, tailored surgical strategies, and secondary prevention of osteoporotic fractures.

Prevalence of fracture progression in fragility fractures of the pelvis: Systematic review and meta-analysis

BACKGROUND

Fragility fractures of the pelvis (FFP) are a growing problem in aging populations. Fracture progression (FP) occasionally occurs during FFP treatment; however, its prevalence remains unclear. This systematic review and meta-analysis aimed to assess the prevalence of FP among patients with FFP.

METHODS

We performed a systematic review and meta-analysis in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. All cohort studies that reported the prevalence of FP in patients with FFP were included. FP was defined as the appearance of additional pelvic fractures after the initial FFP. We searched the CENTRAL, MEDLINE, and EMBASE databases until April 2024. The pooled prevalence was generated using a random-effects model and presented as a 95 % confidence interval (CI) and prediction interval (PI). We assessed the risk of bias in each study using the Joanna Briggs Institute's Prevalence Critical Appraisal Tool.

RESULTS

This review included eight studies (925 patients). The pooled prevalence of FP in patients with FFP was 11 % (95 % CI, 5-19 %; 95 % PI, 0-44 %). Subgroup analysis showed that the pooled prevalence of FP in patients with FFP (conservative treatment vs. surgery for initial FFP) was 16 % (95 % CI, 9-24 %) and 2 % (95 % CI, 0-11 %), respectively (test for subgroup difference, P = 0.03). Additional analysis showed that in patients with FP, the pooled prevalence of the fractured site (ipsilateral site, contralateral site, and both sites) was 66 %, 12 %, and 19 %, respectively. The pooled prevalence of fractured bone (pubis, ischium, ilium, and sacrum) was 25 %, 0 %, 15 %, and 68 %, respectively. The risk of bias in the patient sampling method and sufficient data analysis in all included studies was high.

CONCLUSION

This review suggests that the prevalence of FP in patients with FFP is relatively high. Clinicians should recognize FP as a possible diagnosis in patients experiencing additional pain after FFP. However, further prospective studies with adequate patient sampling are required to confirm the true prevalence.

Comparison of the zonal distribution of calcium salt density and fat marrow in bone-healthy and osteoporotic sacra: an image data analysis using quantitative computed tomography and magnetic resonance imaging

PURPOSE

Pathogenesis of sacral fragility fractures is not fully understood. This study investigates zonal distribution of calcium salt and fat marrow in intact bone-healthy and osteoporotic pelvis. In addition, in unilateral sacral fractures, the fracture side was compared with the intact side.

METHODS

CT and MRI images of 37 pelves were analyzed. Zonal calcium salt distribution by Hounsfield units (HU) was recorded for each CT dataset. Fat marrow content was measured in MRI mDixon-Quant sequence. The cohort was divided: intact pelves with (PEO, HU < 100, n = 8) and without osteoporosis (PE, HU ≥ 100, n = 14) based on the mean HU value in LWK5. A third group consisted of patients with osteoporosis and unilateral fractures (PEOFx, n = 10).

CONCLUSION

The results suggest that in PEO sacral alae experience disproportionate skeletal rarefaction. This concerns the sacral ala at the S1 level (- 25 ± 55), whereby the calcium salt content is so low that it corresponds to the S3 level of healthy bone (- 20 ± 21 HU). This explains the occurrence of transalar fractures in the load-transmitting zone S1. In PEOFx, the calcium salt density was higher and the fat content was lower on the fractured side than on the intact side, indicating bony compacting due to lateral compression and fat displacement due to hematoma in the accident mechanism. This study makes an important contribution to the understanding of the development of sacral fragility fractures. Furthermore, impaction of the cancellous bone within the fracture can be demonstrated.

Conservative or operative therapy in patients with a fragility fracture of the pelvis: study protocol for a prospective, randomized controlled trial

BACKGROUND

The incidence of fragility fractures of the pelvis is rising. Whereas the treatment for FFP type I, III, and IV is clear, the optimal treatment for FFP type II remains a topic of discussion. Traditionally these fractures have been treated conservatively. However, there is a shift toward early surgical stabilization with percutaneous screw fixation to reduce pain and promote mobility in an already frail patient population. High-quality evidence, however, is lacking. Therefore, a randomized clinical trial was designed to compare conservative management to early percutaneous screw fixation in patients with type II fragility fractures.

METHODS

This is a monocenter randomized controlled trial. All patients with a FFP type II are screened for inclusion. After obtaining informed consent, patients are randomized between conservative management and surgical stabilization. Conservative management consists of early mobilization under guidance of physiotherapy and analgesics. Patients randomized for surgical treatment are operated on within 72 h using percutaneous screw fixation. The primary endpoint is mobility measured by the DEMMI score. Secondary endpoints are other dimensions of mobility, pain levels, quality of life, mortality, and morbidity. The total follow-up is 1 year. The required sample size is 68.

DISCUSSION

The present study aims to give certainty on the potential benefit of surgical treatment. Current literature on this topic remains unclear. According to the volume of FFP at the study hospital, we assume that the number of patients needed for this study is gathered within 2 years.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04744350. Registered on February 8, 2021.

Do we need to fix the anterior fracture component in insufficiency fractures of the pelvis? A biomechanical comparison on an FFP type IIIc fracture in an osteoporotic pelvic bone model

There is a growing understanding of the specific characteristics of insufficiency fractures of the pelvis and of general requirements for the treatment of affected patients with focus on early mobilization and effective pain reduction as the main goals of therapy. While there is consensus on the significance of achieving stability of the dorsal pelvic ring structures there is still an open discussion about the potential benefits of additional stabilization of an anterior fracture component. Within a biomechanical test setup, two established methods of dorsal fracture fixation were tested under axial loading (25-1200 N; 1000 test cycles) on an explicit osteoporotic bone model (n = 32) with a standardized FFP type IIIc fracture with and without additional fixation of the anterior fracture component. Dorsal fixation was performed with and long and a short 7.3 mm cannulated screw in S1 in one group (n = 16), and a trans sacral bar with an additional short 7.3 mm cannulated screw in S1 in the other group (n = 16). Half of the samples received a 7.3 mm cannulated retrograde transpubic screw for anterior fixation. The fixation with the trans sacral bar and the additional anterior screw fixation showed the highest rate of stability (p = 0.0014), followed by the double SI-screw fixation with stabilization of the anterior fracture (p = 0.0002). During testing, we observed the occurrence of new sacral fractures contralateral to the initial fracture in 22/32 samples. The results let us assume that stabilization of an additional anterior fracture component relevantly improves the stability of the entire ring construct and might prevent failure of the dorsal stabilization or further 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.

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

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

Comparative outcome of different treatment options for fragility fractures of the sacrum

BACKGROUND

Fragility fractures of the sacrum (FFS) have been detected more and more frequently in recent times, and the incidence will continue to increase due to increasing life expectancy. The aim of this study was to compare the clinical outcome of conservative, interventional and surgical treatment of FFS.

METHODS

Retrospectively, 292 patients (276 women, 16 men) with confirmed FFS were followed up over a period of 2 years. The age of the women was Ø 81.2 (58 - 99) and that of the men Ø 78.1 (76 - 85) years. The pain was quantified using a VAS. Fractures were classified in accordance with the Rommens and Hofmann and with the Denis classification using conventional X-rays, CT and MRI. A QCT of the lumbar spine was performed to quantify bone mineral density. Concomitant diseases of every patient were recorded. An interdisciplinary case conference determined the individual treatment concept considering the age, type of fracture, pain level and comorbidities with classification into conservative, interventional (any type of sacroplasty) or surgical treatment. Over the course pain and independence were measured, complications and patient satisfaction were documented. A vitamin D determination was done, and existing comorbidities were included.

RESULTS

Patients with a pain level of ≤5 benefited from the conservative therapy measures, with pain levels > 5 significantly delaying the development of mobility. After sacroplasty, the pain reduced significantly, which caused a rapid improvement in mobility without any significant difference being found between vertebro- (VSP), balloon (BSP), radiofrequency (RFS) and cement sacroplasty (CSP). In terms of pain reduction and mobilization, the surgical treated patients benefited from osteosynthesis, although more complex fracture types with lumbopelvic stabilization took longer. Overall, there were no deaths during the hospital stay. Mortality after 12 months was 21.7% for the conservative, 8.4% for the interventional and 13.6% for the surgical therapy group; the differences are significant. For patients in the conservative therapy group who were difficult to mobilize due to pain, the mortality increased to 24.3%. Over 24 months, patients achieved the best independence after sacroplasty. At 12 and 24 months, subjective satisfaction with the therapies was best after sacroplasty, followed by osteosynthesis and conservative measures. All patients had a pronounced vitamin D deficiency and manifest osteoporosis. Cardiovascular pathologies were the main concomitant diseases.

CONCLUSIONS

Patients with FFS with a low level of pain benefit from conservative therapy measures, whereby complications and mortality increase significantly in the case of persistent immobilizing pain. Patients with an unacceptable level of pain resulting from non-dislocated fractures benefit significantly from sacroplasty. Patients with unstable and displaced fractures (Rommens and Hofmann type III and IV) should be operated on promptly. Different techniques are available for sacroplasty and osteosynthesis, which lead to an improvement of independence and a reduction in mortality.

[Sacral fragility fractures: risk factors and outcomes after cement sacroplasty]

BACKGROUND

The objective of the present study on patients with fragility fractures of the sacrum (FFS) was to assess existing risk factors and clinical outcomes after cement sacroplasty (CSP).

PATIENTS AND METHODS

68 patients (64 women, 4 men) with previous FFS were followed up retrospectively. CT and MRI images were used to classify fractures according to Denis et al. and Rommens and Hofmann. Bone mineral content was determined by QCT in all patients. Concomitant diseases as well as central and peripheral fractures were recorded, considering the patient's medical history and X‑ray images. Vitamin D levels were also determined. If conservative therapy was unsuccessful, CSP was performed. The results were documented on the basis of pain development, physical independence, patient satisfaction, complication rate and mortality.

RESULTS

The age of the women in the study was Ø 83.2 (72-99) and that of the men Ø 77.8 (76-85) years. 42.4% had a Denis type 1, 4.2% a Denis type 2, 0% a Denis type 3, 43.3% a Denis type 1-2 and 10.1% a Denis type 1-2-3 fracture zone. FFP type II a to II c fractures were found in 88.2%, FFP type III c in 7.4% and FFP type IV b in 4.4%. Bilateral FFS were found in 68.8%. The average bone mineral content (BMC) was 35.4 (2-74) mg/ml, and the average vitamin D value was 8.8 (0-28) nmol/l. Other osteoporosis-associated fractures were found in around 50% of the patients. After CSP, patients showed a rapid and significant (p < 0.001) reduction in pain and sustained clinical improvement.

CONCLUSION

FFS fracture risk factors were found to be female gender, advanced age, existing osteoporosis and severe vitamin‑D deficiency. Patients with non-displaced FFS who could not be mobilised due to pain experienced sustained benefit from CSP.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

BACKGROUND

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

PATIENTS AND METHODS

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

RESULTS

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

CONCLUSION

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

A Case of Fragility Fracture of the Pelvis Initially Diagnosed as Osteoarthritis of the Hip

We present the case of a 58-year-old woman who presented with anterior groin pain, initially diagnosed with hip osteoarthritis (OA), scheduled for total hip arthroplasty, and subsequently diagnosed with an occult fragility fracture of the pelvis (FFP) by preoperative computed tomography (CT) examination. We diagnosed the patient with pre-existing hip OA and a bilateral sacrum and left pubic tubercle fracture that exacerbated the groin pain. We operated on the FFP followed by simultaneous bilateral total hip arthroplasty. Given the high prevalence of hip OA and the increasing incidence of FFP, comorbidity of these 2 entities should be ruled out. Even if hip OA is apparent, plain radiographs are insufficient to rule out FFP, necessitating a thorough clinical examination, followed by a CT examination if an FFP is suspected.

Sacral Insufficiency Fractures

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Primary osteoporosis is the most common cause of sacral insufficiency fractures (SIFs). Therefore, a multidisciplinary team approach is necessary for treatment of the fracture and the underlying biologic pathology, as well as prevention of future fragility fractures.

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The presentation of SIFs typically includes lower back or buttock pain after a ground-level fall or without an identified trauma. Symptoms often have an insidious onset and are nonspecific; consequently, a delay in diagnosis and treatment is common. Clinicians need to have a high index of suspicion, particularly in high-risk patients.

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Postmenopausal women who are >55 years of age are the most common demographic affected by SIFs. Other risk factors include osteoporosis, history of a prior fragility fracture, local irradiation, long-term corticosteroid use, rheumatoid arthritis, metabolic bone disorders, vitamin D deficiency, pregnancy, history of prior multilevel spinal fusion, and malignancy.

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Typical imaging on computed tomography (CT) shows sclerosis of cancellous bone in the sacral ala, with or without a discrete fracture line or displacement. Magnetic resonance imaging is more sensitive than CT and shows hypointense signal on T1-weighted sequences and hyperintensity on T2-weighted or short tau inversion recovery sequences.

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The treatment of SIFs is dependent on the severity of symptoms, fracture displacement, and instability of the pelvis. Accepted treatments include nonoperative rehabilitation, sacroplasty, iliosacral screw fixation, transsacral bar or screw fixation, transiliac internal fixation, and lumbopelvic 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.

Inverse association between sarcopenia and displacement in the early phase of fragility fractures of the pelvis

Objectives

Fragility fractures of the pelvis (FFP) commonly occur in the frail elderly. Displacement in the posterior pelvic ring is recognized as the key sign of instability. This study aims to elucidate the relationship between computer tomography (CT)-based frailty markers and displacement of the posterior pelvic ring within 7 days after injury.

Methods

This retrospective study included 49 patients (42 females, 7 males) with FFP (type I 10, type II 24, type III 12, type IV 3). On a CT slice at the level of the third lumbar vertebra, skeletal muscle area, skeletal muscle radiation attenuation, and skeletal muscle index (SMI) were calculated as sarcopenia markers. Osteopenia was measured with trabecular region of interest attenuation technique on the same CT slice.

Results

There was no difference in the demographics between non-displaced and displaced FFP. CT-based data showed that patients with FFP had osteopenia. However, no difference was found between non-displaced and displaced FFP. SMI was higher in FFP types III/IV than non-displaced FFP when CT-based data on sarcopenia were compared among all patients. Female patients with FFP demonstrated similar results. Logistic regression analysis using the demographics and CT-based markers on sarcopenia and osteopenia revealed that SMI was a potential determinant of displacement of the posterior pelvic ring fractures.

Conclusions

There was inverse association between sarcopenia and displacement of the posterior pelvic ring in the early phase of FFP. Relatively preserved muscle may develop displacement in the elderly with osteopenia.

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.

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.

Current Minimally Invasive Surgical Concepts for Sacral Insufficiency Fractures

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