Cement augmentation of sacroiliac screws in fragility fractures of the pelvic ring-A synopsis and systematic review of the current literature

[Translated article] Spinopelvic dissociation: Current concepts

INTRODUCTION

Spinopelvic dissociation is an uncommon injury, but, at the same time, very serious, since it can associate important complications with high morbidity and mortality. Its low frequency means that the experience of the specialists who have to deal with it is often very limited.

OBJECTIVE

To analyze the treatment indications based in classifications and surgery techniques.

METHOD

A search for scientific articles from high-impact journals was performed through international databases, such as Pubmed, Cochrane Library, Scopus, Science Direct and OVID.

CONCLUSIONS

The management of the injury we are analyzing represents a challenge. The diagnosis is carried out through a meticulous anamnesis and physical examination, supported by imaging tests, where tomography acquires special relevance. The treatment is fundamentally surgical, reserved the conservative option for a few cases. Triangular fixation is nowadays considered the treatment of choice.

Spinopelvic dissociation: Current concepts

INTRODUCTION

Spinopelvic dissociation is an uncommon injury, but, at the same time, very serious, since it can associate important complications with high morbidity and mortality. Its low frequency means that the experience of the specialists who have to deal with it is often very limited.

OBJECTIVE

To analyze the treatment indications based in classifications and surgery techniques.

METHOD

A search for scientific articles from high-impact journals was performed through international databases, such as Pubmed, Cochrane Library, Scopus, Science Direct and OVID.

CONCLUSIONS

The management of the injury we are analyzing represents a challenge. The diagnosis is carried out through a meticulous anamnesis and physical examination, supported by imaging tests, where tomography acquires special relevance. The treatment is fundamentally surgical, reserved the conservative option for a few cases. Triangular fixation is nowadays considered the treatment of choice.

Stabilization of Traumatic Iliosacral Instability Using Innovative Implants: A Biomechanical Comparison

(1) Background: Demographic changes over the past decade have had a significant impact on pelvic ring fractures. They have increased dramatically in the orthogeriatric population. Surgeons are faced with implant fixation issues in the treatment of these fragility fractures. This study compares two innovative implants for stabilizing the iliosacral joint in a biomechanical setting. (2) Methods: An iliosacral screw with a preassembled plate allowing the placement of an additional short, angular stable screw in the ilium and a triangular fixation system consisting of a fenestrated ilium screw and an iliosacral screw quasi-statically inserted through the "fenestra" were instrumented in osteoporotic artificial bone models with a simulated Denis zone 1 fracture. Biomechanical testing was performed on a servo-hydraulic testing machine using increasing, synchronous axial and torsional sinusoidal cyclic loading to failure. (3) Results: The SI-Plate and TriFix showed comparable stiffness values. The values for fracture gap angle and screw tip cutout were significantly lower for the TriFix compared to the SI-Plate. In addition, the number of cycles to failure was significantly higher for the TriFix. (4) Conclusions: Implant anchorage and primary stability can be improved in iliosacral instability using the triangular stabilization system.

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.

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.

FRAGILITY FRACTURES OF THE SACRUM: A SILENT EPIDEMIC

Fragility fractures of the sacrum (FFS) are caused by low-energy trauma in the elderly population. Due to the nuanced symptomatology, many FFS remains unrecognized and the prevalence is underestimated. The clinical presentation varies, typically presenting with weightbearing low back pain without even remembering of a previous trauma. Radiographs are usually insufficient for the diagnosis and second level imaging modalities are required. In particular, magnetic resonance demonstrated the highest diagnostic accuracy. Treatment should aim to guarantee early mobilization and weightbearing, efficient pain relief and early discharge from the hospital to a proper facility for rehabilitation. Conservative treatment is reserved to non-displaced fractures with an adequate pain relief within one week allowing early mobilization. Otherwise, surgical treatment must be preferred. Nowadays, minimally invasive techniques, such as ileo-sacral screws or trans-sacral bar osteosynthesis, are safe and effective procedures and have overcome open procedures. In more complex patterns, with complete dissociation between the pelvic ring and the ilio-lumbar spine, spino-pelvic fixation is the procedure of choice.

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

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

The surgical management of highly unstable fragility fractures of the sacrum with spinopelvic dissociation: A case series and proposal of a surgical treatment algorithm

INTRODUCTION

U- and H-shaped fragility fractures of the sacrum (FFP IVb) are unstable fractures. Non-operative treatment may be associated with impaired walking abilities, chronic pain and the potential loss of independency. However, different treatment options are still controversially debated. The aim of surgical treatment includes sufficient fracture stability for immediate full weight bearing and good pain control postoperatively. A new surgical treatment algorithm was developed. This algorithm was evaluated in a cohort of geriatric patients with FFP type IVb regarding surgical complications and patient-related outcome.

METHODS

Retrospective case series. Patients ≥65 years, admitted with FFP IVb between 01/2017 and 12/2020 were included. Pelvic CT was performed and the surgical technique was chosen according to the proposed surgical treatment algorithm. For this algorithm, the technique of fracture stabilisation was adapted to sacral anatomy and the specific fracture pattern to minimize the impact of surgery and postoperative complications without compromising a sufficient fracture stability. Pain levels, complications and surgical revisions were recorded. Level of independency, walking abilities and -aids were compared 3- and 12- months postoperatively to the pre-injury situation.

RESULTS

Twenty-three patients were included. Outcome parameters could be obtained in 20 patients (85%) after three months and in 18 patients (78%) patients one year postoperatively. All patients were treated according to the algorithm. Sixteen patients received two transilio-transsacral screws (TI-TSS), whereas either lumbopelvic fixation (LPF) combined with a TI-TSS or bilateral ilio-sacral screws (ISS) was performed four times. Three patients underwent bilateral ISS into S1 with one TI-TSS into S2. Three days postoperatively, median pain VAS was 2 (0-8) compared to 7 (4-10) before surgery. One loosened TI-TSS was removed six weeks postoperatively. Three-month mortality was 14% (n=3). At one-year follow-up, all patients regained their pre-injury level of walking abilities.

CONCLUSIONS

Restoration of walking abilities, preservation of independency and efficient pain control can be achieved with surgical fixation of FFP type IVb fractures. With the proposed surgical algorithm, the fixation techniques are adapted to the fracture pattern to minimize the surgical burden.

LEVEL OF EVIDENCE

IV.

[Cement augmentation in pelvic ring fractures]

Cement augmentation of sacroiliac (SI) screws in the posterior pelvic ring has been shown to provide greater biomechanical stability in cadaveric studies. Pelvic ring fractures are relatively rare compared to the total number of fractures. Nevertheless, the 1‑year mortality rate of up to 27% is very high, especially for geriatric pelvic ring fractures and is also largely associated with reduced mobility due to the fracture. The primary goal of treatment is therefore the restoration of patient mobility. This requires the achievement of sufficient stability of the pelvic ring. As osteoporosis is often a causative factor for the pelvic ring fracture, a more stable anchoring of the implants in the osteoporotic bone can be achieved by cement augmentation. This article presents the possibilities of cement augmentation of the pelvic ring and describes the technique of cement-augmented SI screws.

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.

Three-dimensional digital anatomical measurement of modified sacroiliac screws

Purpose

To rebuild a model of the pelvis and effectively simulate the trajectory of modified sacroiliac screws, we measured the parameters of each screw and screw channel and assessed the safety and feasibility of the parameters in adults.

Method and materials

One hundred (50 males and 50 females) normal adult pelvic computed tomography (CT) images were randomly selected and imported into Mimics software to rebuild the three-dimensional pelvis model. In these models, each ideal channel of modified screws was simulated, and then we obtained the precise parameters of screws and channels using Mimics and Three-matic software.

Results

The results of the comparison (right vs. left) showed that there were no significant differences in any of the angles, radius or M1SI parameters (the first modified sacroiliac). However, one parameter (BS) of M2SI (the second modified sacroiliac), two parameters (AP and BS) of M3SI (the third modified sacroiliac), and three parameters (AP, BS, L) of M4SI (the fourth modified sacroiliac) were statistically significant (P < 0.05). The result of comparison (between genders) showed that there were no significant differences in M1SI and M2SI; in contrast, the radius, length and the α angle of M3SI and M4SI were significantly different between genders (P < 0.05), and the radius of M4SI required special attention. If the radius of the limiting screw channel was > 3.50 mm, 52 cases (52%, 24 males and 28 females) could not complete the M4SI screw placement among 100 samples. If the radius of the limiting screw channel was > 3.0 mm, a total of 10 cases (10%, 2 males and 8 females) could not complete the M4SI screw placement.

Conclusion

Through the measurement of 100 healthy adult real three-dimensional pelvic models, we obtained the parameters of each modified sacroiliac screw and measured the three angles of each screw based on international coordinates for the first time, which can instruct clinical application.

Fragility fractures of the pelvis in the older population

Pelvic fractures are an increasingly common injury seen in the older population and represent a significant burden of morbidity and mortality in this age group, as well as a large financial burden on the health service. It is well established that early fixation of femoral neck and acetabular fractures improves outcomes and increases the chances of patients returning close to their premorbid functional baseline. However, fixation of fragility fractures of the pelvis is less well established in current practice. There has been recent development of novel stabilisation techniques for unstable pelvic fractures, designed to tackle the difficulties associated with fixation in poor bone quality, along with medical trials of parathyroid hormone analogue treatment. However, it is still current practice to manage nearly all fragility fractures of the pelvis conservatively. In this article, we consider whether the development of surgical stabilisation techniques for pelvic fragility fractures may have the potential to improve the well-described morbidity and mortality associated with them.

Is cement-augmented sacroiliac screw fixation with partially threaded screws superior to that with fully threaded screws concerning compression and pull-out force in fragility fractures of the sacrum? - a biomechanical analysis

Background

Providing a stable osteosynthesis in fragility fractures of the pelvis can be challenging. Cement augmentation increases screw fixation in osteoporotic bone. Generating interfragmentary compression by using a lag screw also improves the stability. However, it is not known if interfragmentary compression can be achieved in osteoporotic sacral bone by cement augmentation of lag screws.

The purpose of this study was to compare cement-augmented sacroiliac screw osteosynthesis using partially versus fully threaded screws in osteoporotic hemipelvises concerning compression of fracture gap and pull-out force.

Methods

Nine fresh-frozen human cadaveric pelvises with osteoporosis were used. In all specimens, one side was treated with an augmented fully threaded screw (group A), and the other side with an augmented partially threaded screw (group B) after generating a vertical osteotomy on both sides of each sacrum. Afterwards, first a compression test with fracture gap measurement after tightening of the screws was performed, followed by an axial pull-out test measuring the maximum pull-out force of the screws.

Results

The fracture gap was significantly wider in group A (mean: 1.90 mm; SD: 1.64) than in group B (mean: 0.91 mm; SD: 1.03; p = 0.028).

Pull-out force was higher in group A (mean: 1696 N; SD: 1452) than in group B (mean: 1616 N; SD: 824), but this difference was not statistically significant (p = 0.767).

Conclusions

Cement augmentation of partially threaded screws in sacroiliac screw fixation allows narrowing of the fracture gap even in osteoporotic bone, while resistance against pull-out force is not significantly lower in partially threaded screws compared to fully threaded screws.

Accuracy of screw stabilization of the dorsal pelvic ring using a hybrid operating room: 5 Year experience in a level 1 trauma center

INTRODUCTION

Accuracy for screw placement in the dorsal pelvic ring can be enhanced using intraoperative 3D navigation. Advances in intraoperative imaging lead to benefits for pelvic surgery. New c-arms are equipped with flat panel detectors, which have a larger detector and assure higher image quality with accompanying dose reduction. A hybrid OR is defined by a fixed imaging system in an operating room providing the benefit of the surgical environment in combination with advanced intraoperative imaging. Aim of our investigation was to analyze the accuracy of navigated sacroiliac (SI) and transsacral transiliac (TSTI) screws in the dorsal pelvic ring, which were implanted with a hybrid OR in the first five years of use.

MATERIAL AND METHODS

All percutaneous SI or TSTI screws implanted in the hybrid OR using intraoperative navigation in the first 5 years of utilization (between June 2012 to June 2017) were included. Intraoperative 3D-scans and postoperative computed tomography were examined for screw perforation.

RESULTS

210 SI and TSTI screws were implanted in 187 patients using intraoperative navigation in the hybrid-OR. 90.6 % of SI screws showed no cortical perforation. 6,3 % had a grade 1, 2.4 % a grade 2 and 0.8 % a grade 3 perforation. In 80.7 % of TSTI screws no perforation and in 13.3 % a grade 1 perforation was detected. 3.6 % showed a grade 2 and 2.4 % a grade 3 perforation. No significant difference between both screw types regarding the grade of cortical perforation could be seen. No significant relation between perforation rate and year of operation could be detected.

CONCLUSION

Intraoperative navigation in a hybrid OR ensures a high accuracy for SI screws. Due to the large field of view and high image quality TSTI screws can be safely implanted in S1 and S2. Utilization of a hybrid-OR is accompanied with a steep learning curve.

Biomechanical stability of sacroiliac screw osteosynthesis with and without cement augmentation

BACKGROUND

Percutaneous sacroiliac (SI) screw fixation is the standard operative treatment of traumatic disruptions to the posterior pelvic ring. The technique offers good outcomes and early postoperative mobilization, which is vital in elderly patients with fragility fractures of the pelvis. While a double-screw technique has been shown to provide optimal biomechanical stability compared to a single-screw construct, anatomic variations and patient-specific characteristics may prevent the safe insertion of two SI screws. We aimed to determine whether cement augmentation of a single SI screw would provide biomechanical stability comparable to that of the double-screw technique.

METHODS

Three sacroiliac screw osteosynthesis configurations were tested on 10 human cadaveric pelvis specimens: a single cannulated screw; two cannulated screws; and a single, cement-augmented cannulated screw. Displacement and stiffness of the anterior and posterior pelvic ring after fixation with each technique were measured under axial load. Results where compared using linear regression and paired t-tests.

RESULTS

A single uncemented screw offered significantly worse stability in the anterior pelvis compared to a double-screw technique (P < 0.05) and to a single cement-augmented screw technique (P < 0.05). There was no significant difference in anterior pelvic ring stability between the single cement-augmented screw technique and the double-screw technique (P > 0.05). There was no significant difference in the stability of the posterior pelvic ring between the three techniques (P > 0.05).

CONCLUSIONS

A single cement-augmented cannulated sacroiliac screw provides biomechanical stability similar to that of a non-augmented double-screw technique in the treatment of posterior pelvic ring fractures.

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.

Percutaneous operative treatment of fragility fractures of the pelvis may not increase the general rate of complications compared to non-operative treatment

Purpose

Despite an increasing number of fragility fractures of the pelvis (FFP) over the last 2 decades, controversy persists on their therapy with special regard to potential complications. Therefore, the present study compared the complication rates and in-hospital mortality of non-operative therapy, percutaneous treatment and open reduction and internal fixation (ORIF) of pelvic fractures in elderly patients.

Methods

All consecutive patients treated for FFP between January 2013 and December 2017 aged 65 years or older were retrospectively identified from an institutional database. Demographic data and specific patient data were collected with a special focus on pre-existing comorbidities. General and surgical complications, hospital length of stay (LOS) and mortality rates were compared.

Results

379 patients (81.3 ± 7.5 years; 81% female) were identified, 211 (55.7%) were treated non-operatively, 74 (19.5%) percutaneously and 94 (24.8%) with ORIF. The rate of general complications did not differ between treatment groups (non-operative: 21.8%; percutaneous: 28.4%; ORIF: 33.0%; p = 0.103). Surgery-related complications were twofold more frequent in the ORIF group as than in the percutaneously treated group (18.1% vs. 9.5%). The LOS differed significantly (non-operatively: 8.9 ± 7.1 days; percutaneous: 16.6 ± 8.2 days; ORIF: 19.3 ± 12.8 days; p < 0.001). Hospital mortality rate was higher in patients with ORIF (5.3%) than percutaneous treatment (0%) (p = 0.044).

Conclusions

Complication rates and hospital mortality in elderly patients with FFPs are high and associated with long LOS. For surgical treatment of FFPs, the complication rate and mortality can be significantly reduced using percutaneous procedures compared to ORIF. Therefore, percutaneous surgery should be preferred where possible.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00068-021-01660-w.

Minimally invasive posterior locked compression plate osteosynthesis shows excellent results in elderly patients with fragility fractures of the pelvis

Purpose

Fragility fractures of the pelvis (FFP) are common in older patients. We evaluated the clinical outcome of using a minimally invasive posterior locked compression plate (MIPLCP) as therapeutic alternative.

Methods

53 Patients with insufficiency fractures of the posterior pelvic ring were treated with MIPLCP when suffering from persistent pain and immobility under conservative treatment.

After initial X-ray, CT-scans of the pelvis were performed. In some cases an MRI was also performed to detect occult fractures. Postoperatively patients underwent conventional X-ray controls. Data were retrospectively analyzed for surgical and radiation time, complication rate, clinical outcome and compared to the literature.

Results

Patients (average age 79.1 years) underwent surgery with operation time of 52.3 min (SD 13.9), intra-operative X-ray time of 9.42 s (SD 9.6), mean dose length product of 70.1 mGycm (SD 57.9) and a mean hospital stay of 21.2 days (SD 7.7).

13% patients (n = 7) showed surgery-related complications, such as wound infection, prolonged wound secretion, irritation of the sacral root or clinically inapparent screw malpositioning. 17% (n = 9) showed postoperative complications (one patient died due to pneumonia 24 days after surgery, eight patients developed urinal tract infections).

42 patients managed to return to previous living situation. 34 were followed-up after a mean period of 31.5 (6–90) months and pain level at post-hospital examination of 2.4 (VAS) with an IOWA Pelvic Score of 85.6 (55–99).

Conclusion

We showed that MIPLCP osteosynthesis is a safe surgical alternative in patients with FFP 3 and FFP 4. This treatment is another way of maintaining a high level of stability in the osteoporotic pelvic ring with a relatively low complication rate, low radiation and moderate operation time and a good functional outcome.

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.