OF-Pelvis classification of osteoporotic sacral and pelvic ring fractures

Mortality After Iliosacral Screw Fixation for Osteoporotic Pelvic Ring Fractures

Background

Fragility fractures of the posterior pelvic ring are associated with osteoporosis and are becoming more common with demographic change. Known limitations of conservative therapy include a significant loss of autonomy and high mortality. Surgical stabilisation using percutaneous sacroiliac (SI) or trans-iliac trans-sacral (TITS) screws, has been established to increase mobility, but long-term results have not yet been studied.

Materials and Methods

138 patients with percutaneous SI and TITS screw fixation of the posterior pelvic ring in osteoporotic fragility fractures were followed up for more than a year postoperatively in this retrospective study. Thereby, all patients were operated in the conventional supine position in a hybrid operating room consisting of a fixed, robot-assisted 3D flat-panel detector and a navigation system.

Results

34 patients were male and 104 female. The mean age was 77.6 ± 9 years. 26 patients were ASA 1 + 2, 93 patients ASA 3 and 19 patients ASA 4. 80 fractures were classified as FFP 2, 23 FFP 3 and 35 FFP 4. Time to surgery was 127.5 ± 113.2 hours. Hospitalisation lasted an average of 15.7 ± 8.5 days. At the time of discharge, 68.8% of the patients had regained their original mobility, while 31.2% remained limited. The home situation remained unchanged in 73.9% of the patients, worsened in 26.1% and improved in 2.8%. 90.6% of the screw fixations showed no signs of loosening. In 9.4%, loosening could not be ruled out radiologically, but a surgical revision was not necessary. The 1-year mortality rate was 10.1%.

Conclusion

Percutaneous navigated screw fixation of the posterior pelvic ring in fragility fractures is a simple, safe, minimally invasive and precise method with good clinical results in terms of rapid recovery with early mobilization of patients to maintain autonomy and reduce mortality. Further clinical studies with controlled cohorts and a large number of patients with long follow-up periods should be carried out to compare the procedure with other methods. In particular, the question of an additional standardized treatment of the anterior pelvic ring in unstable dislocated fragility fractures should be investigated.

Triangular Screw Placement to Treat Dysmorphic Sacral Fragility Fractures in Osteoporotic Bone Results in an Equivalent Stability to Cement-Augmented Sacroiliac Screws-A Biomechanical Cadaver Study

Background: Sacroiliac screw fixation in elderly patients with pelvic fractures remains a challenging procedure for stabilization due to impaired bone quality. To improve it, we investigated the biomechanical properties of combined oblique sacroiliac and transiliosacral screw stabilization versus the additional cement augmentation of this construct in a cadaver model of osteoporotic bone, specifically with respect to the maximal force stability and fracture-site motion in the displacement and rotation of fragments. Methods: Standardized complete sacral fractures with intact posterior ligaments were created in osteoporotic cadaver pelvises and stabilized with a triangle of two oblique sacroiliac screws from each side with an additional transiliosacral screw in S1 (n = 5) and using the same pelvises with additional cement augmentation (n = 5). A short cyclic loading protocol was applied, increasing the axial force up to 125 N. Sacral fracture-site motion in displacement and rotation of the fragments was measured by optical motion tracking. Results: A maximum force of 65N +/- 12.2 N was achieved using the triangular screw stabilization of the sacrum. Cement augmentation did not provide any significant gain in maximum force (70 N +/- 29.2 N). Only low fragment displacement was observed (2.6 +/- 1.5 mm) and fragment rotation (1.3 +/- 1.2°) without increased stability (3.0 +/- 1.5 mm; p = 0.799; 1.7 +/- 0.4°; p = 0.919) following the cement augmentation. Conclusions: Triangular stabilization using two obliques and an additional transiliosacral screw provides sufficient primary stability of the sacrum. Still, the stability achieved seems very low, considering the forces acting in this area. However, additional cement augmentation did not increase the stability of the sacrum. Given its lack of beneficial abilities, it should be used carefully, due to related complications such as cement leakage or nerve irritation. Improving the surgical methods used to stabilize the posterior pelvic ring will be a topic for future research.

Evolution of treatment of fragility fractures of the pelvic ring. An update

The term "fragility fractures of the pelvis" refers to the disruptions of the pelvic ring that are caused by low energy injuries (such as low-level falls or falls from the standing position) in the elderly population (age over 65 years) in the absence of metastatic bone disease. These fractures are increasing in numbers, due to the aging population, particularly in the developed countries, causing significant morbidity and mortality [1]. Although some fracture patterns are stable enough requiring only conservative treatment, other fracture types can cause significant pelvic instability, demanding a more insistent management protocol.

Dual-energy CT in diagnosing sacral fractures: assessment of diagnostic accuracy and intra- and inter-rater reliabilities

PURPOSE

Evaluating sacral fractures is crucial in fragility fractures of the pelvis. Dual-energy CT (DECT) is considered useful for diagnosing unclear fractures on single-energy CT (SECT). This study aims to investigate the effectiveness of DECT in diagnosing sacral fractures.

METHODS

Thirty cases with suspected sacral fractures underwent SECT, DECT, and MRI. The exams were evaluated by two groups: three inexperienced surgeons (Group I) and three experienced surgeons (Group E). Diagnoses were made initially using SECT (pre-DECT) and then reassessed including DECT (post-DECT). This process was repeated twice. Presence of fractures was determined based on MRI. Sensitivity, specificity, inter-rater and intra-rater reliability, and diagnostic accuracy were calculated. Diagnostic accuracy was statistically compared between two groups.

RESULTS

Sensitivity was 0.73 in pre-DECT and 0.9 in post-DECT, while specificity was 0.83 in pre-DECT and 0.91 in post-DECT. Sensitivity significantly improved with the addition of DECT (McNemar test: p < 0.001). Intra-rater reliability (Fleiss' kappa coefficient) was 0.44 in pre-DECT and 0.76 in post-DECT. Inter-rater reliability (Cohen's kappa coefficient) was 0.6 in pre-DECT and 0.81 in post-DECT. Diagnostic accuracy was significantly lower in group I than group E in pre-DECT (P = 0.019, 0.048), but there was no significant difference between two groups in post-DECT.

CONCLUSION

Combined use of DECT with SECT improved the detection rate of sacral fractures and enhanced intra-rater and inter-rater reliability. High diagnostic accuracy was achieved regardless of the observer's experience. These results indicate that DECT is a useful imaging modality for diagnosing sacral fractures.

Compressive effect and collapse behavior of three different transsacral implants in sacral fragility fractures - a retrospective analysis of 106 cases

PURPOSE

The aim of this study were the retrospective evaluation of the compressive effect and complication rates of transsacral stabilization of osteoporosis-associated sacral fragility fractures in 106 patients using three different implants (6.0 mm sacral bar, n = 32; 7.3 mm screw, n = 26; 7.5 mm ISG-Rod System, n = 48) with regard to the image morphological and clinical-perioperative outcome.

METHODS

For this purpose, the sacral width was determined preoperatively and postoperatively using multiplanar CT reconstructions and correlated with the measured bone density (HU). The results were compared with each other on an implant-specific basis.

RESULTS

A significant compressive effect was found for all implants (6.0 mm sacral bar 7.1 ± 3.4 mm, 7.3 mm screw 6.9 ± 1.8 mm, 7.5 mm ISG-Rod System 8 ± 2.4 mm). No implant-specific difference in compression could be detected. Overall, the washers broke into the iliac cortex in 9% of cases. The subgroups did not differ significantly in this respect (6.0 mm sacral bar: 4 [13%], 7.3 mm screw 1 [1%], 7.5 mm ISG-Rod System (5 [10%], p = 0.581). A correlation between the degree of osteoporosis and the compressive effect could not be demonstrated. Significant implant-specific differences were found in the incision-suture time, with only ø0:39 ± 0:13 h required for implantation of the 7.5 mm ISG Rod System (6.0 mm sacral bar: ø1:09 ± 0:22 h, 7.3 mm screw: ø0:55 ± 0:20 h). The fluoroscopy time was significantly lower with the 7.3 mm screw (ø0:57 ± 0:23 min) and the 7.5 mm ISG Rod System (ø0:42 ± 00:17 min) than with the 6.0 mm sacral bar (ø1:36 ± 0:46 min).

CONCLUSION

A significant compressive effect was demonstrated with all three implants. No implant-specific complications or surgical site complications were identified in either the overall cohort or the subgroups. The 7.5 mm ISG Rod System shows advantages with regard to the duration of surgery and fluoroscopy.

Development and Evaluation of the OF Pelvis Score for Osteoporotic Pelvic Ring Fractures - A Retrospective Assessment of Therapy Recommendations for 107 Patients

The aim of this study was to develop a simple and reliable score which supports decision making between non-operative and operative treatment in patients with osteoporotic pelvic fractures.Between 2018 to 2020, the OF Pelvis Score was developed during a total of 5 meetings of the Working Group on Osteoporotic Fractures of the Spine Section of the German Society of Orthopaedics and Trauma. The OF Pelvis Score as a decision aid between non-surgical and surgical treatment was developed by expert consensus after analysis of numerous geriatric sacral and pelvic ring fractures from several hospitals. Subsequently, retrospective evaluation of the score was performed on consecutive patients from three hospitals.The following parameters were considered relevant to decision making between non-surgical and surgical treatment and were incorporated into the score: fracture morphology using the OF Pelvis Classification, pain status, level of mobilisation, fracture-related neurological deficits, health status, and the modifiers already integrated into the OF Pelvis classification. If the score is < 8, non-surgical therapy is recommended; if the score is > 8, surgical therapy is recommended; if the score is 8, there is a relative indication for surgery. The OF Pelvis Score was then evaluated retrospectively in a total of 107 patients, according to records. The OF Pelvis Score was 8 points in 4 patients (3.7%), all of whom received surgical treatment. Of the remaining 103 patients, 93 received score-compliant therapy (90.3%). Among these, 4 of the patients who did not receive score-compliant care refused the recommended surgery, so the actual therapy recommendation was score-compliant in 94.2%.The OF Pelvis Score can be used to derive a therapy recommendation in many patients in clinical practice. Because of the possible change of clinical parameters during the course of the disease, the score has a dynamic character. In the retrospective evaluation, the recommendations from the OF Pelvis Score were in close accordance with the therapy actually performed.

Comparison of Spectral CT and MRI in Pelvic Ring Fragility Fractures: A Prospective Diagnostic Accuracy Study

Background/Objectives: Fragility fractures of the pelvis (FFP) are characterized by inadequate trauma to a structurally compromised bone, primarily in osteoporosis. Conventional CT studies can be inadequate in identifying FFPs. An MRI of the pelvis is considered the gold standard in diagnosing FFPs. Spectral CT or Dual-Energy CT may have comparable diagnostic accuracy. It provides additional insights into associated bone marrow edema. The aim of this prospective monocentric study is to evaluate the diagnostic accuracy of Spectral CT compared to the gold standard MRI in diagnosing FFP. Methods: Over a 2-year period, patients presenting in the emergency department with clinical suspicion of an FFP were consecutively included. They underwent Spectral CT (GE Revolution 16 cm GSI) upon admission, followed by an MRI. The gold standard for diagnosing FFP is pelvic MRI, showing sensitivity and specificity ranging from 97% to 100%. The acquired images were evaluated and classified using the osteoporotic fractures of the pelvis (OFP) classification. Results: Compared to the reference test, which was the MRI pelvis, the sensitivity of the CT pelvis was determined to be 86.8 (95% confidence interval (CI) 71.9-95.6%) with a specificity of 84.6% (95% CI: 54.6-98.1%, p = 0.453). Spectral CT could identify an additional FFP correctly, exhibiting a sensitivity of 89.5% (95% CI: 75.2-97.1%, p = 0.688), while maintaining the same specificity as the conventional CT. The inter-rater reliability assessment for Spectral CT, conducted by four independent raters, resulted in a Fleiss' Kappa value of 0.516 (95% CI: 0.450-0.582, p < 0.001). Conclusion: The sensitivity of Spectral CT in the detection of pelvic ring fragility fractures shows a slightly lower sensitivity compared to MRI. There were no statistically significant differences observed when compared to conventional CT or MRI. In conclusion, Spectral CT may be beneficial in distinguishing FFP, particularly in cases where a definitive diagnosis is uncertain. Level of Evidence: II.

Biomechanical evaluation of an experimental internal ring fixator (RingFix) for stabilization of pelvic ring injuries on an osteoporotic bone model

During the last decades, effective pain reduction and early mobilization were identified as the central priorities in therapy of insufficiency fractures of the pelvis. For operative treatment minimally-invasive stabilization techniques are favored. While there is consensus on the significance of sufficient dorsal stabilization the role of additional fixation of the anterior fracture component stays under discussion. Within the present study we developed an internal ring fixator system (RingFix) with the question whether an in-itself-closed construct can improve stability of the entire ring structure. RingFix was evaluated on an osteoporotic bone model with a standardized FFP IIIc fracture within an established biomechanical setup regarding its primary stabilization potential. Further, it was compared to transiliac-transsacral screw fixation with and without stabilization of the anterior fracture component. The transiliac-transsacral fixation with separate screw fixation of the anterior fracture showed significantly higher stability than the RingFix and the transiliac-transsacral screw fixation without anterior stabilization. Our results show that stabilization of the anterior fracture component relevantly improves the stability of the entire ring construct. As a bridging stabilizer, RingFix shows biomechanical advantages over an isolated dorsal fracture fixation, but inferior results than direct stabilization of the single fracture components.

Does regional implementation of a clinical pathway for older adult patients with pelvic fragility fractures after low-energy trauma improve patient outcomes (PELVIC): a multicentre, stepped-wedge, randomised controlled trial

INTRODUCTION

Patients with pelvic fragility fractures suffer from high morbidity and mortality rates. Despite the high incidence, there is currently no regional or nationwide treatment protocol which results in a wide variety of clinical practices. Recently, there have been new insights into treatment strategies, such as early diagnosis and minimally invasive operative treatment. The aim of this study is to implement an evidence-based and experience-based treatment clinical pathway to improve outcomes in this fragile patient population.

METHODS AND ANALYSIS

This study will be a regional stepped-wedge cluster randomised controlled trial. All older adult patients (≥50 years old) who suffered a pelvic fragility fracture after low-energetic trauma are eligible for inclusion. The pathway aims to optimise the diagnostic process, to guide the decision-making process for further treatment (eg, operative or conservative), to structure the follow-up and to provide guidelines on pain management, weight-bearing and osteoporosis workup. The primary outcome is mobility, measured by the Parker Mobility Score. Secondary outcomes are mobility measured by the Elderly Mobility Scale, functional performance, quality of life, return to home rate, level of pain, type and dosage of analgesic medications, the number of falls after treatment, the number of (fracture-related) complications, 1-year and 2-year mortality. Every 6 weeks, a cluster will switch from current practice to the clinical pathway. The aim is a total of 393 inclusions, which provides an 80% statistical power for an improvement in mobility of 10%, measured by the Parker mobility score.

ETHICS AND DISSEMINATION

The Medical Research Ethics Committee of Academic Medical Center has exempted the PELVIC study from the Medical Research Involving Human Subjects Act (WMO). Informed consent will be obtained using the opt-out method and research data will be stored in a database and handled confidentially. The final study report will be shared via publication without restrictions from funding parties and regardless of the outcome.

TRIAL REGISTRATION NUMBER

NCT06054165.

PROTOCOL VERSION

V.1.0, 19 July 2022.

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.

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.

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.