Percutaneous iliosacral screw fixation: early treatment for unstable posterior pelvic ring disruptions

Location of Vascular Structures at Risk in Relation to Sacroiliac Joint Fusion

STUDY DESIGN

Retrospective cohort.

OBJECTIVE

This study seeks to establish the normal distribution of the vasculature surrounding the SI joint while also demonstrating associations between distribution and laterality, sex, and ethnicity.

SUMMARY OF BACKGROUND DATA

Sacroiliac (SI) joint fusion surgery has emerged as a viable treatment option for patients suffering from low back pain due to chronic SI joint dysfunction. Due to potential complications from iatrogenic injury to vasculature, it becomes critical to understand normal anatomy and locations with a high vasculature concentration surrounding the SI joint.

METHODS

The authors retrieved medical and radiographic records of patients who underwent computed tomography angiography (CTA) of the pelvis. Anterior and posterior compartments of the SI joint were established on the transverse view by creating an even coronal division of the SI joint. The superior, middle, and inferior compartments were established on the coronal view as three equal transverse compartments. The compartments in which vasculature was visualized were recorded.

RESULTS

Distribution of vasculature around the right and left hemipelvis concentrated in the inferior compartments and decreased in concentration while moving superiorly. Anterior compartments contain a higher vascularity than posterior compartments. Vasculature was present in <3% of the posterior middle, and posterior superior compartments while present in >83% of the inferior compartments. There were no significant differences with respect to vascular distribution when comparing the laterality of the right versus left hemipelvis. There were statistically significant relationships between vascular distribution and sex (P<0.05), as well as across self-reported ethnicity (P<0.05).

CONCLUSIONS

SI screw placement in the posterior superior has the lowest risk of iatrogenic vascular injury. Careful consideration should be taken during SI joint fusion surgery in the inferior compartments due to its high vasculature density.

3D-navigation for SI screw fixation - How does it affect radiation exposure for patients and medical personnel?

BACKGROUND

3D-navigation for percutaneous sacroiliac (SI) screw fixation is becoming increasingly common and several studies report great advantages of this technology. However, there is still limited clinical evidence on the efficacy regarding radiation exposure for patient and personnel.

METHODS

This is a retrospective, single-center cohort study. All patients who underwent percutaneous sacroiliac screw fixation for an injury of the posterior pelvic ring from 2014 to 2021 were screened. Inclusion criteria were: conclusive radiation dosage reports, signed informed consent, a twelve month follow up and a complete data set. Patients were stratified in two groups (3D-navigation (Group 3D-N) vs. control (Group F)) based on the imaging modality used. Primary outcomes were radiation exposure for patient and personnel. Secondary outcomes were reoperations, complications, and intraoperative precision.

RESULTS

Of 392 patients screened, 174 patients (3D-N: n = 50, F: n = 124) could be included for final analysis. We noted a significant reduction of the dose corresponding to potential radiation exposure for medical personnel (-15.3 mGy, 95 %CI: -2.1 to -28.5, p = 0.0232), but also a significant increase of the dose quantifying radiation exposure for patients (+77.0 mGy, 95 %CI: +53.3 to +100.6, p < 0.0001), when using navigation. In addition, the rate of radiographic malplacement was significantly reduced (F: 11.3% vs. 3D-N: 0 %, p = 0.0113) despite a substantial increase in transsacral screw placement (F: 19.4% vs. 3D-N: 76 %).

CONCLUSION

Our data clearly suggests that the use of 3D-navigation for percutaneous SI screw fixation decreases radiation exposure for medical personnel, while increasing radiation exposure for patients. Furthermore, intraoperative precision is improved, even in more challenging operations.

Percutaneous Ilioilial Fixator Versus Percutaneous Iliosacral Screw in Managing Unstable Sacral Fractures: A Prospective Randomised Controlled Study

INTRODUCTION

Unstable sacral fractures with pelvic fractures are challenging to both surgeons and patients, particularly in the immediate post-injury phase and later when definitive fixation is undertaken. Percutaneous iliosacral screw fixation is widely regarded as the gold standard treatment for unstable sacral fractures without spinopelvic dissociation. Closed reduction and percutaneous fixation using iliosacral screws for sacral fractures provide early stabilisation without the need for extensive surgical exposure, thereby mitigating major complications associated with open surgical procedures. A new technique for stabilising unstable sacral fractures is the minimally invasive ilioilial fixator, also called a transiliac internal fixator (TIIF), which has gained more attention for its ability to address challenges associated with sacroiliac screw fixation. The objective of this study is to compare the functional, radiological, and surgical outcomes between the percutaneous iliosacral screw and the ilioilial fixator.

METHODS

A total of 51 patients with sacral fracture injuries sustained between August 2019 and November 2021 were included in this study, with 25 patients in Group A and 26 patients in Group B. Patient randomization was done using computer-generated randomization facilitated by Random Allocation Software (Mahmood Saghaei, Isfahan, Iran). All patients underwent the chosen intervention within 10 days of the trauma. Patients had follow-up at two weeks, six weeks, and 12 months post-treatment. The results of fixation were evaluated radiologically based on the Matta and Tornetta grading system and clinically using the Majeed pelvic scoring system. Complications were detected in both groups during follow-up visits.

RESULTS

The study found no statistically significant differences between the two patient groups in terms of final clinical assessment (p=0.79), radiological assessment (p=0.78), or the need for another operation (p=1.0). Moreover, there were no statistically significant differences between the groups with respect to complication rates (p=0.63) or the time of union (p=0.14). No differences were noted in terms of intraoperative blood loss (p=0.93) or operative time (p=0.34) but for longer incision length in the ilioilial fixator group (p<0.001) and an increased risk of intraoperative radiation exposure in the iliosacral screw group (p<00.1).

DISCUSSION

Although the iliosacral screw is considered a gold standard for unstable sacral fracture, a TIIF is a good alternative with a very satisfactory outcome.

CONCLUSION

Although the iliosacral screw still remains the gold standard for the management of sacral fractures, the ilioilial fixator emerges as a good alternative with comparable functional and radiological outcomes.

Biomechanical Comparison of Double 2.3-mm Headless Cannulated Self-Compression Screws and Single 3.5-mm Cortical Screw in Lag Fashion in a Canine Sacroiliac Luxation Model: A Small Dog Cadaveric Study

OBJECTIVE

 The aim of this study was to evaluate the feasibility of safe positioning of double 2.3-mm headless cannulated self-compression screws (HCS) in a small dog cadaveric sacroiliac luxation model and to compare the static rotational biomechanical properties of fixation repaired using two different screw systems with a minimally invasive osteosynthesis technique: double 2.3-mm HCS and a single 3.5-mm standard cortical screw placed in a lag fashion.

STUDY DESIGN

 A unilateral small dog sacroiliac luxation model was stabilized using double 2.3-mm HCS (n = 11) or a single 3.5-mm cortical screw (n = 11). Radiographic and computed tomography (CT) imaging analyses and biomechanical testing of rotational force on the sacroiliac joint of both fixations were performed. The maximum load at failure and failure modes of each fixation were recorded and compared.

RESULTS

 Fluoroscopically guided percutaneous application of double HCS was safe in a unilateral sacroiliac luxation model in small dogs without violation of the vertebral and ventral sacral foramen. Furthermore, resistance to rotational force applied on fixation of the sacroiliac joint repaired with double 2.3-mm HCS estimated by maximum failure load was significantly higher than that of a single 3.5-mm cortical screw (p < 0.001).

CONCLUSION

 Although this was an experimental cadaveric study, based on our results, the use of smaller double HCS may be beneficial as an alternative to the conventional single lag screw for stabilization of sacroiliac luxation in small dogs.

Percutaneous iliosacral screw insertion with only outlet and inlet fluoroscopic view for unstable pelvic ring injuries: Clinical and radiological outcomes

Background:

Percutaneous iliosacral screw fixation in posterior pelvic ring fractures is challenging and commonly performed under fluoroscopy or navigation techniques. This study aimed to assess the safety and efficacy of percutaneous iliosacral screw implantation under fluoroscopy guidance with only inlet and outlet views.

Methods:

This retrospective study included 58 consecutive unstable posterior pelvic injury patients (36 sacral fractures and 22 sacroiliac joint disruptions) treated with percutaneous iliosacral screws between January 2015 and November 2019. Acceptable inlet radiographs show the anterior cortex of the S1 body superimposed on the S2 body. Acceptable outlet radiographs show the superior pubic symphysis at the level of the S2 foramen and visualize the S1 and S2 sacral foramina. In our technique, the screw was inserted at the inferior half of the outlet view and the posterior half of the inlet view. The time needed for screw insertion and the radiation exposure time was recorded. Intra and postoperative complications were documented. Postoperative computed tomography (CT) scans assessed screw position.

Results:

In total, 69 iliosacral screws were inserted in 58 patients. In postoperative CT scans, the screw position was assessed, 89.8% were in a secure position, and 10.2% had malposition. The mean operation time per screw was 21.18 min and the mean fluoroscopy time per screw was 112 s. There was no evidence of wound infection or iatrogenic neurovascular injury. No reoperation was performed.

Conclusion:

Percutaneous iliosacral screws can be placed using the only outlet and inlet fluoroscopic views with comparable radiological and clinical outcomes to the conventional method.

Percutaneous posterior transiliac plate versus iliosacral screw fixation for posterior fixation of Tile C-type pelvic fractures: a retrospective comparative study

BACKGROUND

This study aimed to compare the clinical outcomes and complications between two minimally invasive surgical techniques: percutaneous transiliac plate fixation and iliosacral (IS) screw fixation for the treatment of Tile C-type pelvic bone fractures.

METHODS

We retrospectively reviewed the data of 77 consecutive patients with Tile C pelvic ring injuries who underwent either percutaneous transiliac plate fixation or IS screw fixation in a single academic center between November 2007 and January 2018. We recorded patients' demographics, surgery-related data, and postoperative surgical outcomes and compared the incidence of complications and revision surgery rates between the two groups.

RESULTS

Overall, 14 patients were included in the plate group, while 63 were included in the IS screw fixation group. No significant differences were observed in the patients' demographics between the two groups except for a longer interval from injury to surgery (13.5 days vs. 5.4 days, P = 0.001). Both groups acquired fracture union in all cases. There was one case of infection requiring surgical debridement in the plating group. Notably, nerve injury (n = 3) and implant loosening (n = 5) occurred in the IS screw group, but the difference was not significant.

CONCLUSIONS

Both percutaneous posterior transiliac plating and IS screw fixation in patients with Tile C-type pelvic bone fractures showed good results. We recommend IS screw fixation as the primary treatment and propose posterior plating as treatment for sacral dysmorphism and bilateral sacral alar fractures in patients with spinopelvic dissociation.

LEVEL OF EVIDENCE

III.

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

OBJECTIVE

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

DESIGN

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

SETTING

A UK tertiary centre hospital.

PARTICIPANTS

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

INTERVENTIONS

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

PRIMARY AND SECONDARY OUTCOME MEASURES

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

RESULTS

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

CONCLUSIONS

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

TRIAL REGISTRATION NUMBER

ISRCTN16719542.

Evaluation of minimally invasive surgical reduction of sacroiliac luxation in toy breed dogs: a cadaver study

Background

Minimally invasive surgery (MIS) technique of sacroiliac luxation in toy breed dogs using cannulated screws has not been described.

Objectives

The purpose of this study was to evaluate the effectiveness of pelvic canal recovery, the reproducibility of successful surgery outcomes, and the acceptable difficulty of the procedure in MIS of sacroiliac luxation in toy breed dogs.

Methods

MIS using 2.3-mm cannulated screws was demonstrated in 12 toy breed dog cadavers with sacroiliac luxation artificially induced. Pre and postoperative radiographs were used to evaluate the pelvic canal diameter ratio (PCDR), hemipelvic canal width ratio (HCWR), and reduction rate. Dorsoventral angle (DVA) and craniocaudal angle (CCA) of the inserted screw were obtained postoperative computed tomographic scan.

Results

The statistically significant difference between the mean pre and postoperative PCDR was found (1.10 ± 0.12 and 1.26 ± 0.11, respectively; p = 0.002), and the mean HCWR close to 1.0 meaning symmetric pelvis also was obtained (0.97 ± 0.07). The mean DVA and CCA were 2.26° ± 1.33° and 2.60° ± 1.86°, respectively.

Conclusions

MIS of sacroiliac luxation using 2.3-mm cannulated screws is applicable to toy breed dogs with acceptable difficulty.

Computed Tomographic Evaluation of the Accuracy of Minimally Invasive Sacroiliac Screw Fixation in Cats

OBJECTIVES

 The aim of this study was to report the use of computed tomography (CT) for postoperative evaluation of the accuracy of sacroiliac reduction and minimally invasive screw fixation in a series of five cats.

MATERIALS AND METHODS

 Medical records between January 2016 and March 2017 of cats presenting to the author's institution were reviewed. Included were cats that had undergone minimally invasive sacroiliac screw fixation with a complete medical record and pre- and postoperative radiographs. Screw size was obtained from the medical records. CT images were acquired prospectively and evaluated to assess joint reduction, relative screw size and screw positioning.

RESULTS

 Six sacroiliac luxations and 6 screws were available. Fixation was achieved with either a 2.4 (n = 1) or 2.7 mm (n = 5), 316L stainless steel, cortical bone screw. Mean screw size as a proportion of sacral diameter was 47.7%. Sacroiliac reduction >90% in the craniocaudal plane and sacral screw purchase >60% of the sacral width were achieved in 3/5 cases. Mean dorsoventral screw angulation was 1.6 degrees (range: -9.7 to 11.7 degrees) and craniocaudal angulation was -4.5 degrees (range: -16.6 to 6.6 degrees). Complications included screw loosening in the one case of bilateral repair and penetration of the neural canal in one case which was not detected with postoperative radiographic evaluation.

CLINICAL SIGNIFICANCE

 CT evaluation provides a useful method for the assessment of sacroiliac reduction and the accuracy of screw placement.

One sacroiliac screw for posterior ring fixation in unstable pelvic fractures

Unstable pelvic injuries are considered uncommon and they are usually associated with high rate of morbidity and mortality. High energy blunt trauma and falling from height are usually the main mechanism of injury. It is a retrospective study that was performed in academic level I trauma center. From September 2015 to December 2019, a consecutive series of 26 patients (7 females), with average age of 32 years with unstable pelvic fracture were included in this study. All patients underwent reduction and percutaneous fixation with one sacroiliac screw posteriorly for each sacroiliac joint and anterior arch fixation of the pelvic ring with either platting or external fixator. The average duration of follow up was 36 months. Clinical results: at the final follow-up, all patients had complete radiological healing of the fractures. The subjective functional assessment yielded excellent for twenty-two patients, good for two patients and fair for two patients. Posterior arch fixation of the pelvic ring with one sacroiliac screw beside anterior arch fixation in unstable fracture pelvis is a sufficient fixation method to maintain the requiring stability to allow complete union of the fracture. Level of Evidence: Therapeutic Level III.

Comparison of lumbopelvic fixation and iliosacral screw fixation for the treatment of bilateral sacral fractures

Background

Bilateral sacral fractures result in traumatic disruption of the posterior pelvic ring. Treatment for unstable posterior pelvic ring fractures should aim for fracture reduction and rigid fixation to facilitate early mobilization. Iliosacral screw fixation (ISF) and lumbopelvic fixation (LPF) were recommended for the treatment of these injuries. No algorithm or gold standard exists for surgery of these fractures.

Purpose

The purpose of this study was to evaluate the differences between ISF and LPF in bilateral sacral fractures regarding intraoperative procedures, complications and postoperative mobilization. The secondary aim was to determine whether demographics influence surgical treatment.

Methods

Over a 4-year period (2016–2019), 188 consecutive patients with pelvic ring injuries were treated at one academic level 1 trauma center and retrospectively identified. Fractures were classified according to the AO/OTA classification system. Seventy-seven patients were treated with LPF or ISF in combination with internal fixation of pubic rami fractures and could be included in this study. Comparisons were made between demographic and perioperative data. Infection, hematoma and hardware malpositioning were used as complication variables. Mobilization with unrestricted weight bearing was used as outcome variable. Follow-up was at least 6 months postoperatively.

Results

Operative stabilization of bilateral posterior pelvic ring injuries was performed in 77 patients. Therefore, 29 patients (females 59%) underwent LPF whereas 48 patients (females 83%) had bilateral ISF. The ISF group was older (76 yrs.) compared to the LPF group (62 yrs.) (p = 0.001), but no differences regarding BMI or comorbidities were detected. Time for surgery was reduced for patients who were treated with ISF compared to lumbopelvic fixation (73 min vs. 165 min; respectively, p < 0.001). But this did not result in reduced fluoroscopic time or radiation exposure. Overall complication rate was not different between the groups. Patients with LPF had a greater length of stay (p = 0.008) but were all weight bearing as tolerated when discharged (p < 0.001).

Conclusion

Bilateral posterior pelvic ring injuries of the sacrum can be sufficiently treated by LPF or ISF. LPF allows immediate weight bearing which may benefit younger patients and patients with an elevated risk for pneumonia or other pulmonary complications. Treatment with ISF reduces operative time, length of stay and postoperative wound infection. Elderly patients may be better suited for treatment with ISF if there is concern that the patient may not tolerate the increased operative time.

Three-dimensional morphometry of the first two sacral segments and its impact on safe transiliac-transsacral screw placement

INTRODUCTION

Percutaneous screw fixation of the posterior pelvic ring is a popular technique to treat unstable pelvic ring lesions. This technique is practicable in both, the high-energy pelvic ring fractures, mostly in the young population as well as the osteoporotic fractures in the elderly. Risk of the transiliac-transsacral screw positioning is that the critical area of nerve root exit has to be passed twice. For secure screw placement, without causing iatrogenic neurovascular injuries, the knowledge of distances to the narrowest areas is essential. Purpose of this anatomical study was to examine the optimal intraosseous screw placement for the first two sacral segments.

MATERIAL/METHODS

Images of uninjured pelves from 50 patients (64-line CT scanner) were evaluated. Then virtual transiliac-transsacral srews were positioned into the first two sacral segments. The distance from the screws' entrance points at the ilium's alar bone to the narrowest portion of the whole pedicle as well as the height and width in this area were measured. Descriptive statistics were used and gender related differences were evaluated using student T-test.

RESULTS

For the first sacral segment the distance to the narrowest zone amounted in mean 62.75 mm, respectively 63.31 mm, depending on the selected way of measurement. For the second segment the mean distance to the neuroforamina was on average 50.61 mm, respectively 51.54 mm. The average height in S1 measured 25.88 mm and the average width 25.49 mm. The average height for S2 was 17.54 mm and the average width 17.61 mm. We could not find any statistically significant gender correlation for the measured distances.

CONCLUSION

Results of this anatomical study may help in performing a safe surgical procedure.

Open reduction and navigated Iliosacral screws for vertically unstable pelvic fractures

AIMS

To evaluate clinical and radiological results of vertically unstable pelvic fractures managed by open reduction and navigated iliosacral screws.

PATIENTS AND METHODS

The study included eleven patients with complex posterior ring fractures with vertical instability admitted to our hospital and managed with CT navigated iliosacral screws. There were 7 type C1, 2 C2 and 2 C3, according to Tile classification. Three patients presented a spino-pelvic dissociation and four a vertical sacral fracture affecting the foramina (Denis 2). Vertical displacement, pelvic deformity and asymmetry were measured. Tornetta and Matta criteria were used to assess the quality of pelvic reduction.

RESULTS

An excellent reduction was achieved in 9 fractures and a good reduction in two. Asymmetry index improved from 13.18 to 2.72. Deformity index improved from 0.049 to 0.010. Only two patients with a Denis 2 fracture showed secondary displacement during follow-up. Four patients presented neurological complications due to their initial injuries. Seven patients were able to resume their previous activities.

CONCLUSION

CT navigated IS screws provide enough stability after an anatomic reduction of the fracture. There was no complication related to screw insertion and adequate screw positioning was achieved in all the cases.

Anatomic relationship between S2 sacroiliac screws' entry points and pelvic external branches of superior gluteal artery

OBJECTIVE

To study the relationship between the pelvic external branches of the superior gluteal artery and the entry area of the S2 sacroiliac screw to provide the anatomical basis and technical reference for avoiding the superior gluteal artery injury during the clinical screw placement.

METHODS

CTA imaging of superior gluteal artery of 74 healthy adults (37 males and 37 females) was randomly selected. The safe bony entry area ('safe area' for abbreviation) of S2 sacroiliac screw in the standard lateral view of the pelvis three-dimensional reconstruction CT image was determined by the CT auxiliary measurement software. The relationship between the pelvic external branches of the superior gluteal artery and the safe area of S2 sacroiliac screw was observed, and the cases in which the artery intersected the safe area were counted. The distance between the safe area and the superior gluteal artery branches closest to it was measured for the cases in which the artery and the safe area did not intersect.

RESULTS

21 of the 74 cases did not have a bone channel of horizontal S2 sacroiliac screw, so they were excluded from this study. In the remaining 53 cases, 12 cases had the deep superior branch of the superior gluteal artery through the safe area of S2 screw (22.6%), and 16 cases had the superficial branch of the superior gluteal artery through the safe area of S2 screw (30.2%). There was no obvious overlap feature and law between the safe area and the superficial and deep superior branches. In 20 cases of the 53 cases, the safe area of S2 screw was located between the deep superior branch and the superficial branch of superior gluteal artery (37.7%), and in 5 cases, the safe area of S2 screw was located behind the superficial branch of superior gluteal artery (9.4%). In the cases where the superior gluteal artery did not intersect the screw entry bony safe area, the part of superior gluteal artery closest to the safe area was located in front or back of the widest part of the safe area.

CONCLUSION

The risk of accidental injury of the deep superior branch and superficial branch of the superior gluteal artery is high during the process of S2 sacroiliac screw placement. Even if the screw entry point is located in the bony safe area, the absolute safety of screw placement cannot be guaranteed. We strongly suggest that a careful and thorough plan is needed before surgery.

Corridor-diameter-dependent angular tolerance for safe transiliosacral screw placement: an anatomic study of 433 pelves

BACKGROUND

The purpose of this study was to determine the angular tolerance of the S1 and S2 segments to accommodate a transiliosacral screw across both sacroiliac joints.

HYPOTHESIS

We hypothesized that the angular tolerance for transiliosacral screw placement would be more constrained than the angular tolerance for iliosacral fixation in pelves where a safe osseous corridor was measured.

MATERIALS AND METHODS

The cortical boundaries of the S1 and S2 sacral segments in 433 pelvic CTs were digitally mapped. A straight-line path was placed within each osseous corridor and extended across both SI joints past the outer iliac cortices. The diameter of the path was increased until it breached the cortex, geometrically determining maximum diameter (Dmax). Angular tolerance for screw placement was calculated with trigonometric analysis of the Dmax value of the corridor, and the average distance from the termination of the osseous corridor to the site of percutaneous insertion. Gender, age, and BMI were evaluated as independent predictors using binomial logistic regression.

RESULTS

The transiliosacral angular tolerance for the S1 and S2 osseous corridors was 1.53 ± 0.57 degrees and 1.02 ± 0.33 degrees, respectively. 68.9% of S1 corridors and 81.1% of S2 corridors had a safe zone (corridor diameter ≥ 10 mm) for transiliosacral placement, 48.3% of the pelves had a safe zone for both corridors, while 5.1% had no safe zones. Females had a less frequent Dmax ≥ 10 mm at S1, 52% vs 67% (p = 0.001), and at S2, 64% vs 86% (p < 0.001).

DISCUSSION

In conclusion, the angular tolerance of 1.53 and 1.03 degrees for the S1 and S2 segments, respectively, creating a narrow interval for safe passage of the trans-iliac and trans-sacral, with approximately 31.1% of patients not having a viable corridor for screw passage. A correlation exist between S1 and S2 corridors with Dmax ≥ 10 mm and the resulting increase in angular tolerance for safe passage of a transilioscral screw.

LEVEL OF EVIDENCE IV

Level Retrospective Cohort.

Two-Dimensional Visualization of the Three-Dimensional Planned Sacroiliac Screw Corridor with the Slice Fusion Method

Insertion of sacro-iliac (SI) screws for stabilization of the posterior pelvic ring without intraoperative navigation or three-dimensional imaging can be challenging. The aim of this study was to develop a simple method to visualize the ideal SI screw corridor, on lateral two-dimensional images, corresponding to the lateral fluoroscopic view, used intraoperatively while screw insertion, to prevent neurovascular injury. We used multiplanar reconstructions of pre- and postoperative computed tomography scans (CT) to determine the position of the SI corridor. Then, we processed the dataset into a lateral two-dimensional slice fusion image (SFI) matching head and tip of the screw. Comparison of the preoperative SFI planning and the screw position in the postoperative SFI showed reproducible results. In conclusion, the slice fusion method is a simple technique for translation of three-dimensional planned SI screw positioning into a two-dimensional strict lateral fluoroscopic-like view.

Percutaneous triangular stabilization of type 3 and type 4 fragility fractures of the pelvis usually leads to fracture healing despite high revision rates

This is a monocentric, retrospective study to analyze radiological findings as well as perioperative and postoperative complications in patients who underwent percutaneous triangular stabilization of type 3 and type 4 fragility fractures of the pelvis. From August 2017 to December 2018, 20 patients were treated surgically. Thirteen patients (65%) were followed-up and received a CT scan of the pelvis after an average time of 14.8 months. A total of 5 patients (38%) had to undergo revision surgery, 2 patients (15%) immediately, 3 patients (23%) in the interval. In 84.6% no fracture line was visible in the sacrum. Fracture healing of the anterior pelvic ring was observed in all cases. Our results show that percutaneous triangular stabilization of type 3 and type 4 fragility fractures of the pelvis usually leads to fracture healing. Radiological signs of loosening were observed in 62%, an implant removal due to symptomatic loosening was necessary in 23%.

Temporary External Fixation to Table as a Traction Reduction Aide in the Treatment of Unstable Pelvic Ring Injuries: A Technical Note

Displaced pelvic ring injuries can be challenging to even the experienced orthopedic traumatologist. A temporary external fixation to table construct provides a quick, simple, and accessible means of external skeletal fixation to reliably obtain and maintain stable hemipelvis reduction on the operating room table. The contralateral hemipelvis can be stabilized to the table by use of Steinman pins safely inserted into the subtrochanteric and anterior column regions and later connected to external fixator bars attached to the table. With rigid stabilization, the displaced contralateral pelvic fragment(s) can be reduced in a more vector intentional manner with greater force than the traditional means of pelvic reduction can allow. The skeletal-table fixation technique is presented along with two cases, a combined pelvic-acetabular injury and an isolated pelvic ring injury.

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.

Plate versus sacroiliac screw fixation for treating posterior pelvic ring fracture: a Systematic review and meta-analysis

BACKGROUND

Whether plate fixation or sacroiliac (SI) screw fixation is the better treatment for posterior pelvic ring disruption is controversial. The aim of this systematic review and meta-analysis was to compare the two fixation methods.

MATERIAL AND METHODS

The MEDLINE, Embase, and Cochrane Library databases were systematically searched for studies comparing plate and SI screw fixations in posterior pelvic ring injuries. Intraoperative variables, postoperative complications, and clinical/radiological scores were compared between the techniques.

RESULTS

Eleven studies were included in the qualitative synthesis, and nine in the meta-analysis. The meta-analysis included 202 patients who underwent plate fixation and 258 patients who underwent SI screw fixation. The incision length and mean blood loss were greater in the plate group than in the SI screw group (standard mean difference (SMD) = 7.29, 95% confidence interval (CI): 3.18-11.40; SMD = 5.09, 95% CI: 2.08-8.09, respectively). Patients in the SI screw group had more X-ray exposure than those in the plate group (SMD = -5.96, 95% CI: -7.95-3.97). There were no differences in operation time and intraoperative complications (SMD = -1.42, 95% CI: -3.90-1.05; OR = 0.92, 95% CI: 0.05-18.60, respectively). The duration of hospital stay was longer in the plate group (SMD = 2.21, 95% CI: 1.74-2.68). There were no differences in postoperative neurological complications, infection rate, and nonunion rate (OR = 1.62, 95% CI: 0.20-13.21; OR = 2.10, 95% CI: 0.74-5.94; OR = 1.12, 95% CI: 0.26-4.87, respectively), but implant loosening was more common in the SI screw group (OR = 0.18, 95% CI: 0.04-0.87). There was no difference in revision surgery (OR = 0.23, 95% CI: 0.02-2.14). The total excellent rating according to the postoperative Majeed functional and Matta scores was higher in the SI screw group (OR = 0.43, 95% CI: 0.20-0.91; OR = 0.24, 95% CI: 0.08-0.74, respectively).

CONCLUSIONS

SI screw fixation was superior to plate fixation in the functional and radiological scores, but implant loosening was more common for the treatment posterior pelvic ring injuries.

3D - Navigated percutaneous screw fixation of pelvic ring injuries - a pilot study

INTRODUCTION

Screw fixation of pelvic ring fractures is a common, but demanding procedure and navigation techniques were introduced to increase the precision of screw placement. The purpose of this case series is to demonstrate a lower screw malposition rate using percutaneous fixation of pelvic ring fractures and sacroiliac dislocations guided by navigation system based on 3D-fluoroscopic images compared to traditional imaging techniques and to evaluate the functional outcomes of this innovative procedure.

PATIENT AND METHODS

10 cases of disrupted pelvic ring lesions treated in our hospital from February 2018 to December 2018 were included for closed reduction and percutaneous screw fixation of using with O-Arm and the acquisition by the Navigator. Preoperative assessment was performed on the patients by means of X Ray imaging and CT scan. Routine CT was carried out on third postoperative day to evaluate screw placement. Measures of radiation exposure were extracted directly from reports provided by system. Quality of life was evaluated by SF 36-questionnaire 6 months after surgery.

RESULTS

12 iliosacral- and 2 ramus pubic-screws were inserted. In post-operative CT-scans the screw position was assessed and graded using the score described by Smith. No wound infection or iatrogenic neurovascular damage were observed. No re-operations were performed. The exposure to radiation is, for the patient, slightly greater than that resulting from the use of traditional fluoroscopic systems, while it is naught for the surgical team, which at the time of image acquisition is located outside the room.

DISCUSSION AND CONCLUSION

The execution of an intraoperative 3D-fluoroscopic scan can on its own suffice as a post-operative control examination since its accuracy is similar to that of the post-operative CT. The use of a navigated 3d fluoroscopy exposes the patient to an amount of radiation slightly greater than that of traditional fluoroscopy, but the dose is lower than a CT examination. For the operating team, exposure to radiation is naught. 3D-fluoroscopic navigation is a safe tool providing high accuracy of percutaneous screw placement for pelvic ring fractures. Finally, despite the small cohort of patients studied, the excellent results obtained regarding the patients' quality of life and the absence of complications allow us to look positively at the future of this technique, which needs further studies and improvement.

Comparing the Efficiency, Radiation Exposure, and Accuracy Using C-Arm versus O-Arm With 3D Navigation in Placement of Transiliac-Transsacral and Iliosacral Screws: A Cadaveric Study Evaluating an Early Career Surgeon

OBJECTIVES

To compare the efficiency, radiation exposure to surgeon and patient, and accuracy of C-arm versus O-arm with navigation in the placement of transiliac-transsacral and iliosacral screws by an orthopaedic trauma fellow, for a surgeon early in practice.

METHODS

Twelve fresh frozen cadavers were obtained. Preoperative computed tomography scans were reviewed to assess for safe corridors in the S1 and S2 segments. Iliosacral screws were assigned to the S1 segment in dysmorphic pelvises. Screws were randomized to modality and laterality. An orthopaedic trauma fellow placed all screws. Time of procedure and radiation exposure to the cadaver and surgeon were recorded. Three fellowship-trained orthopaedic trauma surgeons rated the safety of each screw on postoperative computed tomography scan.

RESULTS

Six normal and 6 dysmorphic pelvises were identified. Eighteen transiliac-transsacral screws and 6 iliosacral screws were distributed evenly between C-arm and O-arm. Average operative duration per screw was significantly shorter using C-arm compared with O-arm (15.7 minutes ± 6.1 vs. 23.7 ± 8.5, P = 0.014). Screw placement with C-arm exposed the surgeon to a significantly greater amount of radiation (3.87 × 10 rads vs. 0.32 × 10, P < 0.001) while O-arm exposed the cadaver to a significantly greater amount of radiation (0.03 vs. 2.76 rads, P < 0.001). Two S2 transiliac-transsacral screws (1 C-arm and 1 O-arm) were categorized as unsafe based on scoring. There was no difference in screw accuracy between modalities.

CONCLUSIONS

A difference in accuracy between modalities could not be elucidated, whereas efficiency was improved with utilization of C-arm, with statistical significance. A statistically significant increase in radiation exposure to the surgeon using C-arm was found, which may be clinically significant over a career. The results of this study can be extrapolated to a fellow or surgeon early in practice. The decision between use of these modalities will vary depending on surgeon preference and hospital resources.

Bone density of first and second segments of normal and dysmorphic sacra

Background

Iliosacral screw fixation is safe and effective but can be complicated by loss of fixation, particularly in patients with osteopenic bone. Sacral morphology dictates where iliosacral screws may be placed when stabilizing pelvic ring injuries. In dysmorphic sacra, the safe osseous corridor of the upper sacral segment (S1) is smaller and lacks a transsacral corridor, increasing the need for fixation in the second sacral segment (S2). Previous evidence suggests that S2 is less dense than S1. The aim of this cross-sectional study is to further evaluate bone mineral density (BMD) of the S1 and S2 iliosacral osseous pathways through morphology stratification into normal and dysmorphic sacra.

Materials and methods

Pelvic computed tomography scans of 50 consecutive trauma patients, aged 18 to 50 years, from a level 1 trauma center were analyzed prospectively. Five radiographic features (upper sacral segment not recessed in the pelvis, mammillary bodies, acute alar slope, residual S1 disk, and misshapen sacral foramen) were used to identify dysmorphic characteristics, and sacra with four or five features were classified as dysmorphic. Hounsfield unit values were used to estimate the regional BMD of S1 and S2. Student’s t-test was utilized to compare the mean values at each segment, with statistical significance being set at p < 0.05. No change in clinical management occurred as a result of inclusion in this study.

Results

A statistical difference in BMD was appreciated between S1 and S2 in both normal and dysmorphic sacra (p < 0.0001), with 28.4% lower density in S2 than S1. Further, S1 in dysmorphic sacra tended to be 4% less dense than S1 in normal sacra (p = 0.047). No difference in density was appreciated at S2 based on morphology.

Conclusions

Our results would indicate that, based on BMD alone, fixation should be maximized in S1 prior to fixation in S2. In cases where S2 fixation is required, we recommend that transsacral fixation should be strongly considered if possible to bypass the S2 body and achieve fixation in the cortical bone of the ilium and sacrum.

Level of evidence

Level III.

Results of open reduction internal fixation versus percutaneous iliosacral screw fixation for unstable pelvic ring injuries: retrospective study of 36 patients

INTRODUCTION

Surgical stabilization of posterior pelvic ring fractures can be achieved by closed reduction and percutaneous fixation (CRPF) or by open reduction and internal fixation (ORIF). The aim of the present study is to compare the clinical results of both methods.

MATERIAL AND METHODS

Medical records of 36 patients consecutively operated for unstable pelvic ring injuries were retrospectively reviewed. We compared 22 patients treated with CRPF versus 14 patients stabilized by using ORIF between 2007 and 2017. The Majeed and Pohlemann scores were used to evaluate postoperative functional outcomes. Complications like blood loss, infection rate, Neurological injury, the operative time and the length of hospital stay were analyzed.

RESULTS

The median Majeed pelvic score was 87 points for the CRPF technique compared with 69 points for the ORIF technique. The median Pohlemann score, operative time and length of hospitalization were similar between the two groups. The median blood loss for the CRPF technique was 300 ml compared to 500 ml for the ORIF technique. CRPF and ORIF procedure had each one neurological lesion. There was one case of infection in the ORIF group and none in the CRPF group. No measurements except for the blood loss have reached the significance threshold.

CONCLUSION

The CRPF technique shows a clear decrease in blood loss. There was no statistically significant difference in the functional results, infection rate, neurological injury, operative time and hospital stay between both techniques.

Patient Weight-bearing after Pelvic Fracture Surgery-A Systematic Review of the Literature: What is the Modern Evidence Base?

Background

Little attention in the literature appears to have been paid to the issue of postoperative weight-bearing protocols for different injury patterns after pelvic fracture surgery. The primary aim of this study is to review the currently available literature to define the level of available evidence used to inform surgical decisions on weight-bearing after pelvic fracture surgery. Secondary aims are to assess the published methods of fracture classification, surgical management, and assessment or reporting of patient outcomes.

Methods

A systematic review of the English language literature from 1990 to 2016 was undertaken. Eligible papers were all papers reporting minimum 6-month outcomes following surgery for pelvic fractures in adults. Exclusion criteria included pathological fractures or those resulting from penetrating injury, solely osteoporotic fractures, or series with less than 6 months of follow-up data.

Results

There is very little published scientific data to inform the treating surgeon on postoperative weight-bearing protocols after pelvic fracture surgery, with no randomized trials and only 1 paper out of 122 stating this as a primary aim. More than half of the papers published did not state what postoperative protocol was employed. There is no standardization of outcome measures, with less than 20% of papers using the most common validated outcome scoring system; in contrast, there is good agreement on the use of either the Tile (75%) or Burgess and Young (20%) classification.

Limitations

Due to the lack of published studies looking at the topic of postoperative weight-bearing after pelvic fractures, no specific recommendations are possible. As large numbers of papers were included, they were not individually assessed for bias.

Conclusion

A review of postoperative weight-bearing regimes reveals a nonexistent scientific evidence base from which to make recommendations, although a consensus strategy has been identified. Future research needs to be directed at this topic, as has already been the case in numerous other fracture areas, since the advantages of early mobility are potentially significant. The reported methodology for assessing and reporting patient outcomes after pelvic fracture surgery reveals no consistent standards, and the majority of papers use no specific outcome scoring system.

How to cite this article

Rickman M, Link B-C, Solomon LB. Patient Weight-bearing after Pelvic Fracture Surgery-A Systematic Review of the Literature: What is the Modern Evidence Base? Strategies Trauma Limb Reconstr 2019;14(1):45-52.

Application of the Guiding Template Designed by Three-dimensional Printing Data for the Insertion of Sacroiliac Screws: a New Clinical Technique

This study is aimed to explore the clinical application of the guiding template designed by three-dimensional printing data for the insertion of sacroiliac screws. A retrospective study of 7 cases (from July 2016 to December 2016), in which the guiding template printed by the threedimensional printing technique was used for the insertion of sacroiliac screws of patients with posterior ring injuries of pelvis, was performed. Totally, 4 males and 3 females were included in template group, aged from 38 to 65 years old (mean 50.86±8.90). Of them, 5 had sacral fractures (3 with Denis type I and 2 with type II) and 2 the separation of sacroiliac joint. Guiding templates were firstly made by the three-dimensional printing technique based on the pre-operative CT data. Surgical operations for the stabilization of pelvic ring by applying the guiding templates were carried out. A group of 8 patients with sacroiliac injuries treated by percutaneous sacroiliac screws were analyzed as a control group retrospectively. The time of each screw insertion, volume of intra-operative blood loss, and the exposure to X ray were analyzed and the Matta's radiological criteria were used to evaluate the reduction quality. The Majeed score was used to evaluate postoperative living quality. The visual analogue scale (VAS) was applied at different time points to judge pain relief of coccydynia. All the 7 patients in the template group were closely followed up radiographically and clinically for 14 to 20 months, mean (16.57±2.44) months. Totally 9 sacroiliac screws for the S1 and S2 vertebra were inserted in the 7 patients. The time length for each screw insertion ranged from 450 to 870 s, mean (690.56±135.68) s, and the number of times of exposure to X ray were 4 to 8, mean (5.78±1.20). The intra-operative blood loss ranged from 45 to 120 mL, mean (75±23.32) mL. According to Matta's radiology criteria, the fracture and dislocation reduction were excellent in 6 cases and good in 1. The pre-operative VAS score ranged from 5.2 to 8.1, mean (7.13±1.00). The average one-week/six-month post-operative VAS was (5.33±0.78) and (1.33±0.66), respectively (P<0.05 when compared with pre-operative VAS). The 12-month postoperative Majeed score ranged from 86 to 92, mean (90.29±2.21). The three-dimensional printed guiding template for sacroiliac screw insertion, which could significantly shorten the operation time, provide a satisfied outcome of the stabilization of the pelvic ring, and protect doctors and patients from X-ray exposure, might be a practical and valuable new clinical technique.

Percutaneous Versus Open Treatment of Posterior Pelvic Ring Injuries: Changes in Practice Patterns Over Time

OBJECTIVE

To determine how the utilization of open versus percutaneous treatment of posterior pelvic ring injuries in early-career orthopaedic surgeons has changed over time.

METHODS

Case log data from surgeons testing in the trauma subspecialty for part II of the American Board of Orthopaedic Surgery examination from 2003 to 2015 were evaluated. Current procedural terminology codes for percutaneous fixation (27216) and open fixation (27218) of the posterior pelvic ring were evaluated using a regression analysis.

RESULTS

A total of 377 candidates performed 2095 posterior ring stabilization procedures (1626 percutaneous, 469 open). Total case volume was stable over time [β = -1.7 (1.1), P = 0.14]. There was no significant change in the number of posterior pelvic ring fracture surgery cases performed per candidate per test year [β = 0.1 (0.1), P = 0.50]. The proportion of posterior pelvic ring cases performed percutaneously increased significantly from 49% in 2003 to 79% in 2015 [β = 1.0 (0.4), P = 0.03]. There was a significant decrease in the number of open cases reported per candidate [β = -0.07 (0.03), P = 0.008].

DISCUSSION AND CONCLUSION

Early-career orthopaedic surgeons are performing more percutaneous fixation of the posterior pelvic ring and less open surgery. The impact of this change in volume on surgeon proficiency is unknown and warrants additional research.

Useful Intraoperative Technique for Percutaneous Stabilization of Bilateral Posterior Pelvic Ring Injuries

Treating patients with bilateral posterior pelvic ring injuries can be challenging. Placement of transiliac-transsacral style screws in available S1 or S2 osseous fixation pathways is becoming an increasingly common fixation method for these unstable injuries. We propose a percutaneous technique that sequences reduction and stabilization of 1 hemipelvis with at least 1 transiliac-transsacral screw and then uses the existing transiliac-transsacral screw and accompanying guide wires to assist in temporary stabilization and definitive fixation of the second hemipelvis.

Safe Zone Quantification of the Third Sacral Segment in Normal and Dysmorphic Sacra

OBJECTIVE

To quantify the osseous anatomy of the dysmorphic third sacral segment and assess its ability to accommodate internal fixation.

DESIGN

Retrospective chart review of a trauma database.

SETTING

University Level 1 Trauma Center.

PATIENTS

Fifty-nine patients over the age of 18 with computed tomography scans of the pelvis separated into 2 groups: a group with normal pelvic anatomy and a group with sacral dysmorphism.

MAIN OUTCOME MEASUREMENTS

The sacral osseous area was measured on computed tomography scans in the axial, coronal, and sagittal planes in normal and dysmorphic pelves. These measurements were used to determine the possibility of accommodating a transiliac transsacral screw in the third sacral segment.

RESULTS

In the normal group, the S3 coronal transverse width averaged 7.71 mm and the S3 axial transverse width averaged 7.12 mm. The mean S3 cross-sectional area of the normal group was 55.8 mm. The dysmorphic group was found to have a mean S3 coronal transverse width of 9.49 mm, an average S3 axial transverse width of 9.14 mm, and an S3 cross-sectional area of 77.9 mm.

CONCLUSIONS

The third sacral segment of dysmorphic sacra has a larger osseous pathway available to safely accommodate a transiliac transsacral screw when compared with normal sacra. The S3 segment of dysmorphic sacra can serve as an additional site for screw placement when treating unstable posterior pelvic ring fractures.

A New Modified Method for Inserting Iliosacral Screw versus the Conventional Method

Study Design

Methodological study.

Purpose

To our knowledge, this is the first study to introduce a new modified method for inserting iliosacral screws and to compare its results with those of a conventional method.

Overview of Literature

Previous techniques, such as open reduction and internal fixation, are associated with perioperative hemorrhage, postoperative infection, and neurological deficits. Although percutaneous iliosacral screw insertion confers the advantage of being minimally invasive, leading to less blood loss and a low postoperative infection rate, it harbors the risk of screw malpositioning due to narrow sacral proportions and a high interindividual variability.

Methods

Nine cadaveric pelvises were included in this study, with one hemipelvis of each being assigned to the new modified method and the other to the conventional iliosacral screw insertion method. In the new modified method, the guidewire entry point was determined using a lateral sacral X-ray. To do so, we first identified the anterosuperior quadrant of the S1 body on one hemipelvis. The anterosuperior quadrant was further divided into four imaginary quadrants, and the guidewire was inserted into the posteroinferior quadrant. The guidewire trajectory was perpendicular to the sagittal plane so that the guidewire resembled a single point in the lateral sacral view. Guidewires were inserted into corresponding hemipelves using the conventional method as described in the literature. Subsequently, an axial computed tomography scan with 1-mm fine cuts was obtained, and sagittal and coronal views were reconstructed. The distance of the guidewire from the sacral canal, anterior sacral cortex, and first sacral foramen was measured in axial, sagittal, and coronal views. The minimum measurement among different views was defined as the safety index of the insertion methods. The conventional and new modified methods were then compared in terms of safety and duration of the procedure.

Results

The minimum distance of the guidewire from the S1 foramen and anterior sacral cortex was not significantly different between the two methods. However, the minimum distance between the guidewire and sacral canal was significantly greater in the new modified method than in the conventional method. The duration of guidewire insertion was significantly shorter in the new modified method than in the conventional method.

Conclusions

This new modified method of iliosacral screw insertion could be safely and simply implemented while taking less surgical time than the conventional methods.

Anatomical relation between S1 sacroiliac screws' entrance points and superior gluteal artery

BACKGROUND

To conduct radiologic anatomical study on the relation between S1 sacroiliac screws' entry points and the route of the pelvic outer superior gluteal artery branches with the aim to provide the anatomical basis and technical reference for the avoidance of damage to the superior gluteal artery during the horizontal sacroiliac screw placement.

METHODS

Superior gluteal artery CTA (CT angiography) vascular imaging of 74 healthy adults (37 women and 37 men) was done with 128-slice spiral CT (computed tomography). The CT attendant-measuring software was used to portray the "safe bony entrance area" (hereinafter referred to as "Safe Area") of the S1 segment in the standard lateral pelvic view of three-dimensional reconstruction. The anatomical relation between S1 sacroiliac screws' Safe Area and the pelvic outer superior gluteal artery branches was observed and recorded. The number of cases in which artery branches intersected the Safe Area was counted. The cases in which superior gluteal artery branches disjointed from the Safe Area were identified, and the shortest distance between the Safe Area and the superior gluteal artery branch closest to the Safe Area was measured.

RESULTS

Three cases out of the 74 sample cases were excluded from this study as they were found to have no bony space for horizontal screw placement in S1 segment. Among the remaining 71 sample cases, there are 32 cases (45.1%) where the deep superior branch of superior gluteal artery passes through the Safe Area of S1 entrance point. There was no distinguishing feature and rule on how the deep superior branches and the Safe Area overlapped. In the 39 cases in which superior gluteal artery branches disjointed from the Safe Area, the deep superior branches of superior gluteal artery were the branches closest to the Safe Area and the part of the branch closest to the Safe Area was located in front of the widest part of the Safe Area. The shortest distance between the deep superior branch and the Safe Area is 0.86 ± 0.84 cm.

CONCLUSION

There is a high risk of accidental injury of the deep superior branches of superior gluteal artery in the process of S1 sacroiliac screw placement. Even if the entry points are located in the safe bony entrance area, the absolute secure placement cannot be assured. We suggest that great attention should be paid to make thorough preoperative plans.

Comparison of open reduction versus minimally invasive surgical approaches on screw position in canine sacroiliac lag-screw fixation

Objective: To compare accuracy and consistency of sacral screw placement in canine pelves treated for sacroiliac luxation with open reduction and internal fixation (ORIF) or minimally invasive osteosynthesis (MIO) techniques.

Methods: Unilateral sacroiliac luxations created experimentally in canine cadavers were stabilized with an iliosacral lag screw applied via ORIF or MIO techniques (n = 10/group). Dorsoventral and craniocaudal screw angles were measured using computed tomography multiplanar reconstructions in transverse and dorsal planes, respectively. Ratios between pilot hole length and sacral width (PL/SW-R) were obtained. Data between groups were compared statistically (p <0.05).

Results: Mean screw angles (±SD) were greater in ORIF specimens in both transverse (p <0.001) and dorsal planes (p <0.004). Mean PL/SW-R was smaller (p <0.001) in the ORIF group, yet was greater than 60%. While pilot holes exited the first sacral end-plate in three of 10 ORIF specimens, the spinal canal was not violated in either group.

Conclusions: This study demonstrates that MIO fixation of canine sacroiliac luxations provides more accurate and consistent sacral screw placement than ORIF. With proper techniques, iatrogenic neurological damage can be avoided with both techniques. The PL /SW-R, which relates to safe screw fixation, also demonstrates that screw penetration of at least 60% of the sacral width is achievable regardless of surgical approach. These findings, along with the limited dissection needed for accurate sacral screw placement, suggest that MIO of sacroiliac luxations is a valid alternative to ORIF.

Accuracy of screw fixation using the O-arm® and StealthStation® navigation system for unstable pelvic ring fractures

PURPOSE

Screw fixation for unstable pelvic ring fractures is generally performed using the C-arm. However, some studies reported erroneous piercing with screws, nerve injuries, and vessel injuries. Recent studies have reported the efficacy of screw fixations using navigation systems. The purpose of this retrospective study was to investigate the accuracy of screw fixation using the O-arm^® imaging system and StealthStation^® navigation system for unstable pelvic ring fractures.

METHODS

The participants were 10 patients with unstable pelvic ring fractures, who underwent screw fixations using the O-arm StealthStation navigation system (nine cases with iliosacral screw and one case with lateral compression screw). We investigated operation duration, bleeding during operation, the presence of complications during operation, and the presence of cortical bone perforation by the screws based on postoperative CT scan images. We also measured the difference in screw tip positions between intraoperative navigation screen shot images and postoperative CT scan images.

RESULTS

The average operation duration was 71 min, average bleeding was 12 ml, and there were no nerve or vessel injuries during the operation. There was no cortical bone perforation by the screws. The average difference between intraoperative navigation images and postoperative CT images was 2.5 ± 0.9 mm, for all 18 screws used in this study.

CONCLUSION

Our results suggest that the O-arm StealthStation navigation system provides accurate screw fixation for unstable pelvic ring fractures.

[Percutaneous internal fixation of pelvic fractures. German version]

BACKGROUND

Percutaneous internal fixation of pelvic fractures is increasing in popularity with multiple new techniques reported.

OBJECTIVES

The purpose of this article is to outline the imaging, indication, planning, equipment, surgical technique and complications of these methods.

METHODS

A review of the literature is provided and the techniques for anterior and posterior pelvic stabilization are discussed.

RESULTS

High-quality preoperative CT scans are essential in planning for this technique. The anterior internal fixator ("InFix") is an effective method for stabilizing the anterior ring and should be usually used in conjunction with posterior fixation. Good technique avoids neurovascular injury, which can be a devastating complication. The retrograde anterior column screw (RACS) is a technique that can be used in most patients, although in smaller patients smaller screw diameters may be needed. The entry point for the screw is more lateral in women than men. Iliosacral screws (ISS) are an effective method of posterior stabilization and can be placed using 2D or 3D fluoroscopy, computer navigation or CT navigation.

CONCLUSION

Percutaneous fixation of pelvic fractures requires high-quality imaging and can be aided by computer navigation. Safe techniques are reproducible; however, not all patients and fracture patterns can be treated using these techniques.

Fractures of the pelvic ring

Traumatic disruptions of the pelvic ring are high energy life threatening injuries. Management represents a significant challenge, particularly in the acute setting in the presence of severe haemorrhage. Initial management is focused on preserving life by controlling haemorrhage and associated injuries. Advances in prehospital care, surgery, interventional radiology and the introduction of treatment algorithms to streamline decision making have improved patient survival. As more patients with unstable pelvic injuries survive, the poor results associated with nonoperative management and increasing patient expectations of outcome are making surgical management of these fractures increasingly common. The aim of operative fracture fixation is to correct deformity and restore function. The advent of percutaneous fixation techniques has reduced the morbidity previously associated with large operative exposures and internal fixation.

Pelvic fracture in multiple trauma: A 67-case series

INTRODUCTION

Severe pelvic trauma remains associated with elevated mortality, largely due to hemorrhagic shock.

OBJECTIVE

The main study objective was to test for correlation between fracture type and mortality. The secondary objective was to assess the efficacy in terms of mortality of multidisciplinary management following a decision-tree in multiple trauma victims admitted to a level 1 trauma center.

MATERIAL AND METHODS

Between July 2011 and July 2013, 534 severe trauma patients were included in a single-center continuous prospective observational study. All patients with hemorrhagic shock received early treatment by pelvic binder. Patients with active bleeding on full-body CT or persisting hemorrhagic shock underwent arteriography with or without embolization. Pelvic trauma was graded on the Tile classification. The principle end-point was mortality.

RESULTS

Median age was 40 years (range, 26-48 years), with a 79% male/female sex ratio. Thirty-two of the 67 patients with pelvic trauma (48%) were in hemorrhagic shock at admission. Median injury severity score (ISS) was 36 (range, 24-43). On the Tile classification, 22 patients (33%) were grade A, 33 (49%) grade B and 12 (18%) grade C. Overall mortality was 19%, and 42% in case of hemorrhagic shock. Mortality was significantly higher with Tile C than A or B (58% vs. 9.1% and 12.1%, respectively; P=0.001).

CONCLUSION

Vertical shear fracture (Tile C) was associated with greater mortality from hemorrhagic shock.

LEVEL OF EVIDENCE

IV, case series.

Correct Positioning of Percutaneous Iliosacral Screws With Computer-Navigated Versus Fluoroscopically Guided Surgery in Traumatic Pelvic Ring Fractures

OBJECTIVES

To assess the correct positioning of iliosacral screw in patients with unstable traumatic pelvic ring injury by comparing fluoroscopically guided computer-navigated surgery (CNS) with conventional fluoroscopy (CF) through reviewing postoperative computed tomography (CT) and clinical indicators.

DESIGN

A comparative multicenter cohort study.

SETTING

Two level I Trauma Centers in the Netherlands.

PATIENTS

The computer-navigated group (n = 56) and the CF group (n = 24) were comparable regarding age (mean, 43 years), sex (58%, male), body mass index (25 kg/m), injury severity score (27), injury-to-surgery interval (7 days), and Orthopaedic Trauma Association classification (40% 61-B, 60% 61-C).

MAIN OUTCOME MEASUREMENTS

The position of the iliosacral screws was evaluated on postoperative CT. In addition, clinical morbidity and reoperation were assessed.

RESULTS

In the CNS group, a total of 111 screws were placed (2.0 per patient), of which 83% were placed correctly. In the CF group, 39 screws (1.6 per patient) were placed, 82% of them correctly.Inadequate fixation included neural foramina hit [12 screws (11%) in the CNS group versus 3 screws (8%) in the CF group, P = 0.76] and extraosseous dislocation [7 screws (6%) vs. 4 screws (10%), respectively, P = 0.47]. Five patients required reoperation, all in the CNS group, P = 0.32. We observed more adequate positioning with increased surgical experience, P = 0.12.

CONCLUSIONS

In contrast to what has been suggested by previous studies, we found no benefit from computer-navigated iliosacral screw fixation compared with fluoroscopically guided surgery regarding the correct positioning of iliosacral screw on postoperative CT and related morbidity.

LEVEL OF EVIDENCE

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

Immediate percutaneous sacroiliac screw insertion for unstable pelvic fractures: is it safe enough?

OBJECTIVES

The purpose of this study was to compare the results of immediate and delayed percutaneous sacroiliac screws surgery for unstable pelvic fractures, regarding technical results and complication rate.

DESIGN

Retrospective study.

SETTING

The study was conducted at the Soroka University Medical center, Beer Sheva, Israel, which is a level 1 trauma Center.

PATIENTS

108 patients with unstable pelvic injuries were operated by the orthopedic department at the Soroka University Medical Center between the years 1999-2010. A retrospective analysis found 50 patients with immediate surgery and 58 patients with delayed surgery. Preoperative and postoperative imaging were analyzed and data was collected regarding complications.

INTERVENTION

All patients were operated on by using the same technique-percutaneous fixation of sacroiliac joint with cannulated screws.

MAIN OUTCOME MEASUREMENTS

The study's primary outcome measure was the safety and quality of the early operation in comparison with the late operation.

RESULTS

A total of 156 sacroiliac screws were inserted. No differences were found between the immediate and delayed treatment groups regarding technical outcome measures (P value = 0.44) and complication rate (P value = 0.42).

CONCLUSIONS

The current study demonstrated that immediate percutaneous sacroiliac screw insertion for unstable pelvic fractures produced equally good technical results, in comparison with the conventional delayed operation, without additional complications.

Ilio-Sacral (IS) Screw Fixation for Sacral and Sacroiliac Joint (SIJ) Injuries in Children

BACKGROUND

Treatment of sacral fractures and sacroiliac joint (SIJ) disruption with percutaneous ilio-sacral (IS) screw fixation had become a more popular treatment option. There has been no study that specifically assessed IS fixation in children. The purpose of this study is present our results with fixation of the sacral fractures and SIJ disruption using IS screw in children 18 years old and younger.

METHODS

This is a retrospective review chart for children with sacral fracture or SIJ disruption who were treated by IS fixation in the period from 2000 to 2012. The patients were assessed for the following (age, sex, type of injury, associated injuries, surgery, complications, postoperative return of function, healing of the injury, and return to function).

RESULTS

In the studied period (2000 to 2012), 11 patients who had either sacral fracture (4 patients) or SIJ (7 patients) disruption were treated by IS screws. The average age of these patients was 14 years (range, 6 to 17 y). Six patients had 1 screw and 5 patients had 2 screws. Eight patients had their entire fixation in S1, and 3 patients had 1 screw in S1 and 1 screw in S2. All screws were cannulated and were inserted over a guidewire with fluoroscopy and/or navigation guidance. Five patients had added anterior fixation of the pelvis. One patient was lost for follow-up. All patients (except 1) achieved healing of their injuries with no displacement or implant failure with return of function. One patient had failure of fixation and needed revision. One patient had neurological complication related to screw insertion.

CONCLUSIONS

IS screws can be safely used to treat sacral fractures and SIJ injuries in children. This was feasible in children as young as 6 years old. The complications of the procedure were minimal with good stability obtained by IS screws.

Is Closed Reduction and Percutaneous Fixation of Unstable Posterior Ring Injuries as Accurate as Open Reduction and Internal Fixation?

OBJECTIVES

The objective of this retrospective review was to determine whether a closed reduction technique for unstable pelvic ring injuries is as accurate as an open technique.

DESIGN

Retrospective review.

SETTING

Two academic Level 1 trauma centers.

PATIENTS/PARTICIPANTS

We reviewed the records of 113 patients who had unilateral unstable pelvic ring injuries (Bucholz type 3, OTA type 61-C1) treated with closed reduction and percutaneous fixation (CRPF) or open reduction with internal fixation (ORIF).

INTERVENTION

Sixty patients were treated at one institution with open reduction and percutaneous iliosacral screw fixation. This involved prone positioning and a gluteus maximus sparing approach for direct visualization and reduction of the fracture. A second cohort of 53 patients was treated at a separate institution with closed reduction and percutaneous iliosacral screw fixation. This involved supine positioning and skeletal traction.

MAIN OUTCOME MEASURES

Preoperative and postoperative plain radiographs of the pelvis were reviewed and standardized measurements were made to compare quality of reduction.

RESULTS

We were able to measure displacement within 0.1 mm. Overall reduction quality was slightly better for the CRPF group. The largest average difference in postoperative displacement was seen at the iliac wing height on anteroposterior pelvis radiographs with 6.3 mm (range 0-19.6) in the ORIF group versus 1.9 mm (range 0-4.7) in the CRPF group.

CONCLUSIONS

The closed reduction technique described here is as effective as the ORIF technique in obtaining reduction of unstable pelvic ring injuries (Bucholz type 3, OTA type 61-C1).

LEVEL OF EVIDENCE

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

Stereotactic guidance for navigated percutaneous sacroiliac joint fusion

Arthrodesis of the sacroiliac joint (SIJ) for surgical treatment of SIJ dysfunction has regained interest among spine specialists. Current techniques described in the literature most often utilize intraoperative fluoroscopy to aid in implant placement; however, image guidance for SIJ fusion may allow for minimally invasive percutaneous instrumentation with more precise implant placement. In the following cases, we performed percutaneous stereotactic navigated sacroiliac instrumentation using O-arm^® multidimensional surgical imaging with StealthStation^® navigation (Medtronic, Inc. Minneapolis, MN). Patients were positioned prone and an image-guidance reference frame was placed contralateral to the surgical site. O-arm® integrated with StealthStation® allowed immediate auto-registration. The skin incision was planned with an image-guidance probe. An image-guided awl, drill and tap were utilized to choose a starting point and trajectory. Threaded titanium cage(s) packed with autograft and/or allograft were then placed. O-arm® image-guidance allowed for implant placement in the SIJ with a small skin incision. However, we could not track the cage depth position with our current system, and in one patient, the SIJ cage had to be revised secondary to the anterior breach of sacrum.

Precision insertion of percutaneous sacroiliac screws using a novel augmented reality-based navigation system: a pilot study

PURPOSE

Augmented reality (AR) enables superimposition of virtual images onto the real world. The aim of this study is to present a novel AR-based navigation system for sacroiliac screw insertion and to evaluate its feasibility and accuracy in cadaveric experiments.

METHODS

Six cadavers with intact pelvises were employed in our study. They were CT scanned and the pelvis and vessels were segmented into 3D models. The ideal trajectory of the sacroiliac screw was planned and represented visually as a cylinder. For the intervention, the head mounted display created a real-time AR environment by superimposing the virtual 3D models onto the surgeon's field of view. The screws were drilled into the pelvis as guided by the trajectory represented by the cylinder. Following the intervention, a repeat CT scan was performed to evaluate the accuracy of the system, by assessing the screw positions and the deviations between the planned trajectories and inserted screws.

RESULTS

Post-operative CT images showed that all 12 screws were correctly placed with no perforation. The mean deviation between the planned trajectories and the inserted screws was 2.7 ± 1.2 mm at the bony entry point, 3.7 ± 1.1 mm at the screw tip, and the mean angular deviation between the two trajectories was 2.9° ± 1.1°. The mean deviation at the nerve root tunnels region on the sagittal plane was 3.6 ± 1.0 mm.

CONCLUSIONS

This study suggests an intuitive approach for guiding screw placement by way of AR-based navigation. This approach was feasible and accurate. It may serve as a valuable tool for assisting percutaneous sacroiliac screw insertion in live surgery.

Percutaneous Screw Fixation of Crescent Fracture-Dislocation of the Sacroiliac Joint

Crescent fracture-dislocation of the sacroiliac joint (CFDSIJ) is a type of lateral compression pelvic injury associated with instability. Open reduction and internal fixation is a traditional treatment of CFDSIJ. However, a minimally invasive method has never been reported. The purpose of this study was to assess the outcome of closed reduction and percutaneous fixation for different types of CFDSIJ and present their clinical outcome. The authors reviewed 117 patients diagnosed with CFDSIJ between July 2003 and July 2013. Closed reduction and percutaneous fixation was performed in 73 patients. Treatment selection was based on Day's fracture classification. For type I fractures, fixation perpendicular to the fracture line were performed. For type II fractures, crossed fixation was performed. For type III fractures, fixation was performed with iliosacral screws. Forty-four patients were treated by open reduction and plate fixation. Demographics, fracture pattern distribution, blood loss, incision lengths, revision surgeries, radiological results, and functional scores were compared. All 117 patients were followed for more than 6 months (mean, 14 months [range, 6-24 months]). Blood loss, extensive exposure, duration of posterior ring surgery, duration of hospital stay, and infection rates were lower in the closed group (P<.01). Patients in the closed group achieved better functional performance (P<.01). There were no significant differences in reduction quality (P=.32), revision surgery rates (P=.27), and iatrogenic neurologic injuries (P=.2) between the 2 groups. The authors' results indicate that closed reduction and percutaneous fixation is a safe and effective surgical method for CFDSIJ.

Percutaneous iliosacral screw fixation after osteoporotic posterior ring fractures of the pelvis reduces pain significantly in elderly patients

INTRODUCTION

Osteoporotic posterior ring fractures of the pelvis are common injuries in the elderly, but the treatment of these fractures still remains controversial. Percutaneous iliosacral screw fixation is one surgical option if conservative treatment cannot provide sufficient pain reduction. The aim of this study is to provide short-term results of elderly patients with percutaneous screw fixation.

METHODS

30 patients with posterior ring fractures were treated between 12/2009 and 01/2014 with percutaneous iliosacral screw fixation. Patients' mean age was 78.4 years. Concerning short-term outcome, we focused on initial pain level and postoperative pain reduction together with intra- and postoperative complications.

RESULTS

The average hospital stay was 23.7 days, with surgical treatment performed after an average of 9.2 days. 90% of our patients were female. All 30 patients had a lower level of pain at discharge compared with admission or immediately prior to surgery. The difference in pain level at admission compared with the pain level upon discharge showed a mean reduction from 6.8 to 1.8 with a statistically significant change (P≤0.001). 24 of 30 patients had no registered complications, one screw malpositioning with postoperative nerve irritation occurred.

DISCUSSION

Conventional percutaneous iliosacral screw fixation is a successful operative treatment for elderly patients with persistent lower back pain after unstable posterior ring fractures of the pelvis. Intra- and postoperative complications are rare, so this treatment can be regarded as a safe procedure.

LEVEL OF EVIDENCE

IV (retrospective study).

Investigation of bone quality of the first and second sacral segments amongst trauma patients: concerns about iliosacral screw fixation

Background

Iliosacral screw fixation has become a common method for surgical stabilization of acute disruptions of the pelvic ring. Placement of iliosacral screws into the first sacral (S1) body is the preferred method of fixation, but size limitations and sacral dysmorphism may preclude S1 fixation. In these clinical situations, fixation into the second sacral (S2) body has been recommended. The objective of this study was to evaluate the bone quality of the S1 compared to S2 in the described “safe zone” of iliosacral screw fixation in trauma patients.

Materials and methods

The pelvic computed tomography scans of 25 consecutive trauma patients, ages 18–49, at a level 1 trauma center were prospectively analyzed. Hounsfield units, a standardized computed tomography attenuation coefficient, was utilized to measure regional cancellous bone mineral density of the S1 and S2. No change in the clinical protocol or treatment occurred as a consequence of inclusion in this study.

Results

A statically significant difference in bone quality was found when comparing the first and second sacral segment (p = 0.0001). Age, gender, or smoking status did not independently affect bone quality.

Conclusion

In relatively young, otherwise healthy trauma patients there is a statistically significant difference in the bone density of the first sacral segment compared to the second sacral segment. This study highlights the need for future biomechanical studies to investigate whether this difference is clinically relevant. Due to the relative osteopenia in the second sacral segment, which may impact the quality of fixation, we feel this technique should be used with caution.

Level of evidence

III