Transsacral Screw Research Articles

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

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

Triangular spinopelvic fixation for U-shaped sacral fractures and tile C pelvic disruptions: counter-nutation (anteflexion and rotation) load-bearing instability requires complementary anterior pelvic ring fixation.

Unstable trauma lesion of the spinopelvic junction, including U-shaped sacral fractures and Tile C pelvic ring disruptions, require surgical stabilization in order to realign the bone arches of the pelvis thus reducing the upcoming orthopaedic impairment during sitting, standing, and walking positions, decompress the nerves roots of the cauda equina in a view of reducing neurological impairment, and allow early weight bearing. Even though posterior open modified triangular spinopelvic fixation is particularly efficient for treating unstable trauma lesions of the spinopelvic junction, it may not be sufficient alone in order to prevent long-term counter-nutation, i.e. rotation and anteflexion deformity of the anterior pelvis under load bearing conditions. Such progressive deformation is caused by either the slight rotation of the iliac connectors within the head of iliac screws for spinopelvic constructs, or the slight rotation of sacral cancellous bone around transsacral screws in case of percutaneous procedure. Regardless of the posterior surgical technique that is used, complementary anterior pelvic fixation appears mandatory in order to prevent such deformation over time, which can lead to pelvic asymmetry and then gait imbalance.

Influence of age on pelvic inlet and outlet radiographic views

Background. Unstable fractures of the posterior pelvic ring represent a pressing concern in trauma surgery. Minimally invasive osteosynthesis techniques have gained widespread acceptance in contemporary practice. Accurate radiographic visualization is a critical component for the precise and successful placement of iliosacral and transsacral screws. Obtaining and accurately interpreting X-ray images can pose challenges in specific clinical situations, particularly those involving age-related skeletal changes. The aim of the study is to assess the influence of the patient’s age on the measures of pelvic radiographic inlet and outlet views angles for performing a sacral fracture fixation using cannulated screws. Methods. A retrospective analysis of CT data was conducted on 106 patients with posterior pelvic ring injuries requiring cannulated screw fixation. Preoperative CT scans were reconstructed into sagittal projections. We performed construction and measurement of the true inlet angle, super-inlet angle, pelvic outlet angle, sacral concavity angle, promontory angle, S1 and S2 outlet view angles. Statistical correlation between sacral tilt angle and the patient’s age was assessed. Results. A two-step cluster analysis divided the patient cohort into two groups with significant differences in pelvic outlet angles and age (N1 = 64, N2 = 42). Statistically significant differences were found between the two clusters in all the studied parameters: median values of true pelvic inlet angles were 27.2° [23.2-32.2] and 18.2° [11.4-26.6] respectively (p0.001); super-inlet angles were 42.5° [39.3-47.8] and 36.2° [28.7-42.8] respectively (p0.001); promontory angles were 128.1° [123.3-133.2] and 122.1° [115.6-129.3] respectively (p = 0.003); pelvic outlet angles were 62.6° [58.4-69.6] and 50.3° [45.9-53.5] respectively (p0.001); S1 outlet angles were 51.8° [48.9-56.5] and 46.8° [43.1-50.2] respectively (p0.001); S2 outlet angles were 40.8° [37.3-44.6] and 35.7° [30.9-38.6] respectively (p0.001); the mean of the sacral concavity angles was 174.8°±10.5 and 152.1°±38.2 respectively (p0.001); and the main age was 41.6±18.7 and 69.2±16.1 years respectively (p0.001). A statistically significant inverse correlation between age and pelvic tilt angle (ρ = 0.534; p0.001) was found. A novel diagnostic method for identifying sacral dysmorphism using angle measurement within the S1 bone corridor is presented. The sacrum was considered dysmorphic if the angle was equal to or less than 5°. Conclusions. As the patient’s age increases by one year, pelvic outlet angle decreases by 26°. If pelvic inlet angles are equal to or less than 14.45°, the difficulties in visualizing S1 and S2 outlet views during surgery are to be expected. The median of angles difference before and after anterior sacral tilt correction using a coccyx pad was 9.4° with interquartile range from 7.8° to 11°. Significant anatomical variations in posterior pelvic ring structure were observed among the study cohort. Preoperative CT sagittal reconstructions allow appropriate planning of intraoperative visualization considering expected intraoperative radiographic inlet and outlet views.

Fixation of Sacral Ala Fracture Using a Midfoot Mesh Plate as a Cannulated Screw Washer: A Case Report

Introduction: Sacral fractures are rare but are increasing in incidence among trauma patients. They are associated with a wide variety of complications, most commonly neurologic defects. Case Report: A 59-year old woman initially underwent open reduction internal fixation (ORIF) for a sacral fracture, after which the patient developed an infection, wound complications, and hardware failure. The revision of the iliosacral screws proved challenging in that the standard screw and washer could not achieve sufficient compression of the fracture. Therefore, a modified midfoot mesh plate was cut to size and used as a washer to gain more surface area, achieving fixation. The plate was applied laterally and cut to cover as much surface area as possible without unnecessary bony overhang. A trans-iliac trans-sacral screw was then inserted in the standard fashion, thus allowing the plate to act as a washer. This resulted in an excellent outcome with appropriate fracture healing. Conclusion: We describe the case of an iliosacral screw revision in which a modified midfoot mesh plate was used as a washer. This resulted in appropriate fixation in the revision settings. The principles described to achieve this fixation can be broadly applied in the setting of orthopedic fractures.

Insertion sites of iliosacral screws on the posterior ilium: Implications for posterior pelvic fixation

ObjectivesLateral compression type II pelvic ring injuries can be treated with fixation through open or percutaneous approaches depending on the injury pattern and available osseous fixation pathways. The start site of iliosacral screws to stabilize these injuries should be on the unstable posterior iliac fragment; however, our understanding of start sites for iliosacral screws has not been developed. The purpose of this study is to provide an analysis of iliosacral screw start sites on the posterior ilium to help guide treatment of pelvic ring injuries. MethodsOne-hundred and seventeen consecutive patients at an academic level I trauma center with pelvic ring injuries who underwent surgical treatment with iliosacral screws were included in the final analysis. The start sites of iliosacral screws with confirmed intraosseous placement on a postoperative computed tomography were mapped on the posterior ilium and analyzed according to the sacral segment and type of iliosacral screw. ResultsOne-hundred and seventeen patients were included in the final analysis. Of the total of 272 iliosacral screw insertion sites analyzed, 145 (53%) were sacroiliac-style screws and 127 (47%) were transsacral screws. The insertion sites for sacroiliac-style screws and transsacral screws at different sacral segment levels can vary but have predictable regions on the posterior ilium relative to reliable osseous landmarks. ConclusionsIliosacral screws start sites on the posterior ilium have reliable regions that can be used to plan posterior fixation of pelvic ring injuries.

Analysis of Eligibility of the S1 Corridor for the Trans-Sacral Screw Placement in Geriatric Patients

Abstract Background Minimal-invasive placement of a trans-sacral screw represents an increasingly popular method of fixation for Fragility Fractures of the Pelvis (FFP), with variable upper sacral anatomy representing the main challenge. Little is known about the variability of sacral anatomy in the geriatric population and the potential effect of osteoporosis on the upper sacral anatomy and thus S1 corridor morphology. Aims To examine the eligibility (>12 mm) of the S1 corridor for the trans-sacral screw placement in a geriatric population and to analyse what pelvic dysmorphism signs might serve as predictors for an ineligible S1 corridor. Methods We analysed S1 corridor in pelvic CT scans of 107 geriatric patients without history of fracture or other pelvic pathology. First, the eligibility for the trans-sacral screw placement was determined by measuring the width and the height of the central portion of the S1 corridor. Then, pelvises were examined for signs of dysmorphism. The correlation of these signs with the ineligible S1 corridor was analysed. Results In our geriatric population with average age of 79,55 ± 8.79 years (male : female 0.88) 44% of S1 corridors were not eligible for a trans-sacral screw. In this ineligible group the height was shown to be a more significant limiting dimension (90,9%), compared to the width in 68,2% (p<0.05). Mamillary processes, not recessed sacrum and dysmorphic sacral foramina were present in 38,3%, 34,6%, and 26,2% respectively, with not recessed sacrum demonstrating a significant correlation with a too narrow S1 corridor (p<0.05). Conclusion The analysed geriatric population demonstrates a high prevalence of a too narrow S1 corridor, which makes a placement of a trans-sacral screw risky or even impossible. The height of the S1 corridor represents the main limiting factor with a dysmorphism sign of a not recessed sacrum being a significant predictor for the ineligible S1 corridor.

Variables Associated With Loss of Fixation of Retrograde Rami Screws in Minimally Displaced Lateral Compression Type 1 Pelvic Ring Injuries.

To evaluate variables associated with loss of fixation of retrograde rami screws in the treatment of stress-positive minimally displaced lateral compression type 1 (LC1) injuries. Retrospective comparative study. Level 1 trauma center. Stress-positive minimally displaced (<1 cm) LC1 pelvic ring injuries treated with retrograde rami screws. Loss of fixation, defined as >5 mm of pelvic fracture displacement based on the radiographic tear-drop distance or >5 mm of implant displacement on follow-up radiographs; revision surgery for loss of fixation. Thirty-eight patients with 40 retrograde rami screws were analyzed. Median patient age was 64 years (interquartile range 42.5-73.3 years), 71.1% (n = 27/38) were female, and 52.6% (n = 20/38) of injuries were secondary to low-energy mechanisms. Loss of fixation occurred in 17.5% (n = 7/40) of screws with 10% (n = 4/40) requiring revision surgery. On univariate analysis, patients who had a loss of fixation were more likely to have greater dynamic displacement on stress radiographs (22.0 vs. 15.2 mm; median difference 5.6 mm, confidence interval [CI] -19.2 to 10.3; P = 0.04), unicortical rami screws (71.4% vs. 9.1%; proportional difference 62.3%, CI 8.8%-22.6%; P = 0.001), and partially threaded rami screws (71.4% vs. 21.2%; proportional difference 50.2%, CI 10.0%-77.6%; P = 0.01). The remaining variables had no observed association ( P ≥ 0.05) with loss of fixation, including age, sex, body mass index, energy of injury mechanism, tobacco use, American Society of Anesthesiologist score, sacral fracture type, distal rami fractures, rami comminution, number of sacral screws, fully threaded sacral screws, transsacral screws, or rami screw diameter. On multivariate analysis, only unicortical rami screws ( P = 0.01) remained associated with loss of fixation. Retrograde rami screws had a high rate of loss of fixation in minimally displaced LC1 pelvic ring injuries, and this was associated with unicortical screws. These screws should be avoided when possible. Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Comparative Analysis of Three Posterior-Only Surgical Techniques for Isthmic L5-S1 Spondylolisthesis.

To compare adults with isthmic L5-S1 spondylolisthesis who were treated with three different surgical techniques: PS-only, TS, and transforaminal lumbar interbody fusion/posterior lumbar interbody fusion (TLIF/PLIF). This is a retrospective analysis of adults with L5-S1 isthmic spondylolisthesis (grade ≥2) who underwent primary all-posterior operations with pedicle screws. Patients were excluded if they had <1 year follow-up, anterior approaches, and trans-sacral fibular grafts. Patient demographics and surgical, radiographic, and clinical data were compared between groups based on the method of anterior column support: none (PS-only), TS, and TLIF/PLIF. Sixty patients met inclusion criteria (male patients 21, female patients 39, average age 47 ± 15 years, PS-only 16; TS 20; TLIF/PLIF 24). TS patients more commonly had high-grade slips and markedly greater slip percentage, lumbosacral kyphosis, and pelvic incidence. The three groups were similar for smoking status, visual analog scores/Oswestry Disability Index scores (VAS/ODI), surgical data, and average follow-up (40.1 ± 31.2 months). All groups had similarly notable improvements in Meyerding grade and lumbosacral angle. Slip reduction percentage was similar between groups. While there was a markedly higher overall complication rate for PS-only constructs, all groups had similarly notable improvements in ODI and VAS back scores. All-posterior techniques for L5-S1 isthmic spondylolisthesis resulted in excellent improvement in preoperative symptoms and HRQoL scores and similar radiographic alignment. Trans-sacral screws were more commonly used for high-grade slips. The use of anterior column support resulted in fewer overall complications than posterior-only instrumentation.

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

Background3D-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. MethodsThis 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. ResultsOf 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 %). ConclusionOur 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.

The Use of a Robotic Arm for Fixation of Pelvic Fractures.

The objective of this study was to evaluate unplanned cortical or neuroforaminal violation of iliosacral and transsacral screw placement using fluoroscopy versus screw placement using a robotic arm. This is a prospective cohort study. Single surgeon, single North American level 1 trauma center. Radiographic and clinical data for 21 consecutive adult trauma patients with pelvic ring fractures undergoing surgical treatment were prospectively collected. Treatment consisted of iliosacral and/or transsacral screws with or without anterior fixation. Ten patients were treated with the assistance of a robotic arm. Eleven patients were treated with standard fluoroscopic techniques. Thirty-two screws were placed and evaluated with postoperative computed tomography or O-arm spins to assess unplanned cortical or neuroforaminal violation. Violations were graded according to the Gertzbein and Robbins system for pedicle screw violation, categorizing screw violation in 2-mm increments. The postoperative images were blindly reviewed by 5 fellowship-trained orthopaedic traumatologists. The treating surgeon was excluded from review. The Mann-Whitney U test on the Gertzbein and Robbins system results demonstrated significantly (P = 0.02) fewer violations with robotic assistance. χ2 analysis of whether there was a cortical violation of any distance demonstrated significantly (P = 0.003) fewer cortical violations with robotic assistance. There were no neurovascular injuries in either group. Robotic assistance demonstrated significantly fewer unplanned cortical or neuroforaminal violations. Further research is needed with additional surgeons and sites to evaluate the accuracy of iliosacral and transsacral screw placement with robotic assistance. Therapeutic, level II.

PELVİS TİPLERİNİN TRANS-SAKRAL VİDA KORİDOR ÇAPINA ETKİSİNİN DEĞERLENDİRİLMESİ (BİLGİSAYARLI TOMOGRAFİ VERİLERİ KULLANILARAK YAPILAN RETROSPEKTİF ANALİZ.)

Aims: The aim of this study was to investigate the effect of pelvis type on the trans-sacral(TS) screw corridor diameter.&#x0D; Methods: Pelvis computed tomography (CT) scans between 2017 and 2020 were retrospectively reviewed. Age, gender, height, weight and body mass index (BMI) of the patients were determined during the CT examination. Pelvic CT scans were examined using the imaging system's multi-plane reconstruction (MPR) mode, and the TS screw corridor was measured for both the upper and second sacral segments. In addition, pelvic incidence (PI), sacral tilt (SS), and pelvic tilt (PT) values were measured. Pelvis typing was performed using the large transverse diameter, anteroposterior diameter, interspinous, intertuberocytosis, transverse outlet diameter, sagittal mid-pelvic diameter, and sagittal outlet values.&#x0D; Results: 81(38%) male and 132(62%) female patients were included in the study. Gynecoid pelvis type was more common in females and android pelvis in males (p &lt; 0.001). The largest diameters in the TS screw corridor at the S1 level belonged to the anthropoid pelvis type. However, in the TS corridor at the S2 level, there was a significant difference between the pelvis-type groups in the mean values of AP and CC (p &lt; 0.001). The effect of gender difference on the TS screw corridor width at the S1 and S2 levels was significant. An adequate corridor width for the TS screw corridor was detected in 50.8% of females and 67.9% of males at the S1 level, while in 21.2% of females and 70.4% of males at the S2 level.&#x0D; Conclusions: There is a significant difference in the dimensions of the trans-sacral screw corridor according to the pelvis type and gender, with the largest diameter observed in the anthropoid pelvis type and males. In critical situations, especially in males and individuals with android-anthropoid pelvis, the trans-sacral screw option should be considered primarily not only for the S1 trans-sacral corridor but also for the S2 trans-sacral corridor in pelvic posterior ring injuries

Higher pelvic incidence values are a risk factor for trans-iliac trans-sacral screw malposition in sacroiliac complex fracture treatment

BackgroundPercutaneous iliosacral (IS) screw fixation and trans-iliac trans-sacral (TITS) screw fixation are clinically effective treatments of posterior pelvic sacroiliac fractures. In order to accurately assess the sacrum position relative to the pelvis, pelvic incidence (PI) is a commonly utilized radiographic parameter in sagittal view. This study aimed to investigate and compare the surgical outcomes and radiographic parameters of IS or TITS screw fixations for the treatment of posterior sacroiliac complex fractures with different PI values.Materials and methodsThe data on patients with posterior pelvic sacroiliac fractures who underwent percutaneous IS or TITS screw fixations, or both, at a single level I trauma center between January 2017 and June 2020 were reviewed. We documented the patient characteristics and fracture types, reviewed surgical records, and measured the radiographic parameters via plain films and multi-planar computed tomography (mpCT) images. Radiographic variations in PI, sacral slope, pelvic tilt, sacral dysmorphism, pelvic ring reduction quality, screw deviation angles, screw malposition grading, and iatrogenic complications were documented and analyzed.ResultsA total of 85 patients were included, and 65 IS and 70 TITS screws were accounted for. Patients were divided into two groups according to screw fixation method and further divided into four sub-groups based on baseline PI values. The PI cutoff values were 49.85° and 48.05° in the IS and TITS screw groups, respectively, according to receiver operating characteristic analysis and Youden's J statistic. Smaller PI values were significantly correlated with sacral dysmorphism (p = 0.027 and 0.003 in the IS and TITS screw groups, respectively). Patients with larger PI values were at a significantly increased risk of screw malposition in the TITS screw group (p = 0.049), with no association in the IS screw group. Logistic regression confirmed that a larger PI value was a significant risk factor for screw malposition in the TITS screw group (p = 0.010). The post-operative outcomes improved from poor/fair (at 6 months) to good/average (at 12 months) based on the Postel Merle d'Aubigné and Majeed scores, with no significant differences between subgroups.ConclusionsBoth percutaneous IS and TITS screw fixations are safe and effective treatments for posterior pelvic sacroiliac fractures. Due to the higher risk of screw malposition in patients with larger PI values, it is crucial to identify potential patients at risk when performing TITS screw fixation surgery.Level of evidence:Level III.

Sacroiliac versus transiliac–transsacral screw osteosynthesis in osteoporotic pelvic fractures: a biomechanical comparison

IntroductionPelvic fractures were often associated with high-energy trauma in young patients, but data show a significant increase in osteoporotic pelvic fractures in old age due to the progressive demographic change. There is an ongoing discussion about the best fixation techniques, which are ranging from lumbopelvic fixation to sacral bars or long transiliac–transsacral (TITS) screws. This study analyzes TITS screw osteosynthesis and sacroiliac screw osteosynthesis (SI), according to biomechanical criteria of fracture stability in osteoporotic human pelvic cadavers ex vivo.MethodsTen osteoporotic cadaveric pelvises were randomized into two groups of 5 pelvises each. An FFP-IIc fracture was initially placed unilaterally and subsequently surgically treated with a navigated SI screw or a TITS screw. The fractured side was loaded in a one-leg stance test setup until failure. Interfragmentary movements were assessed by means of optical motion tracking.ResultsNo significant difference in axial stiffness were found between the SI and the TITS screws (21.2 ± 4.9 N and 18.4 ± 4.1 N, p = 0.662). However, there was a significantly higher stability of the fracture treatment in the cohort with TITS-screws for gap angle, flexion, vertical movement and overall stability. The most significant difference in the cycle interval was between 6.000 and 10.000 for the gap angle (1.62 ± 0.25° versus 4.60 ± 0.65°, p = 0.0001), for flexion (4.15 ± 0.39 mm versus 7.60 ± 0.81 mm, p = 0.0016), interval 11.000–15.000 for vertical shear movement (7.34 ± 0.51 mm versus 13.99 ± 0.97 mm, p < 0.0001) and total displacement (8.28 ± 0.66 mm versus 15.53 ± 1.07 mm, p < 0.0001) for the TITS and the SI screws.ConclusionsThe results of this biomechanical study suggest a clear trend towards greater fracture stability of the TITS screw with significantly reduced interfragmentary movement. The application of a TITS screw for the treatment of the osteoporotic pelvic ring fracture may be prioritized to ensure the best possible patient care.

Is a Washer a Mandatory Component in Young Trauma Patients with S1-S2 Iliosacral Screw Fixation of Posterior Pelvis Ring Injuries? A Biomechanical Study.

Background and purpose: Cannulated screws are standard implants for percutaneous fixa-tion of posterior pelvis ring injuries. The choice of whether to use these screws in combination with a washer is still undecided. The aim of this study was to evaluate the biomechanical competence of S1-S2 sacroiliac (SI) screw fixation with and without using a washer across three different screw designs. Material and Methods: Twenty-four composite pelvises were used and an SI joint injury type APC III according to the Young and Burgess classification was simulated. Fixation of the posterior pelvis ring was performed using either partially threaded short screws, fully threaded short screws, or fully threaded long transsacral screws. Biomechanical testing was performed under progressively increasing cyclic loading until failure, with monitoring of the intersegmental and bone-implant movements via motion tracking. Results: The number of cycles to failure and the corresponding load at failure (N) were significantly higher for the fully threaded short screws with a washer (3972 ± 600/398.6 ± 30.0) versus its counterpart without a washer (2993 ± 527/349.7 ± 26.4), p = 0.026. In contrast, these two parameters did not reveal any significant differences when comparing fixations with and without a washer using either partially threaded short of fully threaded long transsacral screws, p ≥ 0.359. Conclusions: From a biomechanical perspective, a washer could be optional when using partially threaded short or fully threaded long transsacral S1-S2 screws for treatment of posterior pelvis ring injuries in young trauma patients. Yet, the omission of the washer in fully threaded short screws could lead to a significant diminished biomechanical stability.

Retrospective evaluation of percutaneous 3D-navigated screw fixation for fragility fractures of the sacrum: technical notes and four-year experience

The incidence of fragility fractures of the sacrum is increasing due to demographic changes. In this study, we introduce the 3D-navigated monoportal percutaneous sacroiliac screw fixation (PSS) as a technical advancement for treating fragility fractures of the sacrum. We included all patients who underwent the 3D-navigated monoportal PSS for fragility fractures of the sacrum. The fractures were classified using the Fragility Fractures of the Pelvis score (FFP). We provide a step-by-step illustration of the surgical technique. The objective of this study was to assess the feasibility and safety of the investigated technique. Forty-six patients (36 female, 10 male) with a median age of 81.5 years were included in the study. The fracture classification revealed 23 FFP2 (50%), 5 FFP3 (11%), and 18 FFP4 (39%) fractures. In 35 cases (76%), only transsacral screws were implanted in S1 and S2, with an average incision-to-suture time of 52.6 min. The remaining eleven patients underwent additional anterior pelvic ring fixation, lumbar instrumentation, or kyphoplasty. There were no instances of nerve root, vascular, or pelvic organ injuries. The median postoperative in-hospital stay was six days. Out of the 36 patients who were followed up, four patients required revision surgery due to screw loosening. No significant risk factor for screw loosening was identified in the multiple regression analysis. The presented monoportal PSS technique for fragility fractures of the sacrum is a promising minimally invasive approach with a low complication rate and excellent short-term outcomes.

Cerclage augmentation of S1-S2 transsacral screw fixation in osteoporotic posterior pelvis ring injuries: A biomechanical feasibility study.

Injuries of the posterior pelvic ring are predominantly associated with osteoporosis. Percutaneously placed screws transfixing the sacroiliac joint have become the gold standard for their treatment. However, screw cut-out, backing-out, and loosening are common complications. One promising option could be cerclage reinforcement of cannulated screw fixations. Therefore, the aim of this study was to evaluate the biomechanical feasibility of posterior pelvic ring injuries fixed with S1 and S2 transsacral screws augmented with cerclage.Twenty-fourcomposite osteoporotic pelvises with posterior sacroiliac joint dislocation were stratified into four groups for S1-S2 transsacral fixation using either (1) fully threaded screws, (2) fully threaded screws with cable cerclage, (3) fully threaded screws with wire cerclage, or (4) partially threaded screws with wire cerclage. All specimens were biomechanically tested under progressively increasing cyclic loading until failure. Intersegmental movements were monitored by motion tracking. The transsacral partially threaded screw fixation with wire cerclage augmentation resulted in significantly less combined angular intersegmental movement in the transverse and coronal plane versus its fully threaded counterpart (p = 0.032), as well as in significantly less flexion versus all other fixations (p ≤ 0.029). Additional cerclage augmentation could be performed intraoperatively to improve the stability of posterior pelvic ring injuries treated with S1-S2 transsacral screw fixation. Further investigations should follow to consolidate the current results on real bones and possibly consider execution of a clinical study.

Quantification of the Safe Zone of the First to Third Sacral Segments for Transiliac-Transsacral Screw Fixation in Normal and Dysmorphic Sacra.

Transiliac-transsacral screw fixation is widely used to stabilize unstable posterior pelvic ring injuries. Preoperative radiographic assessment of the safe osseous corridor is necessary because the safe space of sacrum is narrower for transiliac-transsacral screw placement than for traditional iliosacral screw placement. However, the radiographic assessment has rarely been studied in the Taiwanese population. We retrospectively analyzed 100 patients with pelvic computed tomography images and divided them into normal and dysmorphic pelvis groups. To determine the safe osseous space, we recorded cross-section area, cross-sectional diameter of the safe zone (CS-szD), and safe zone width on axial view (Ax-szW) in the S1 to S3 segments. The prevalence of dysmorphic pelvis was 48% among all patients. In the S1 segment, no differences were found in the cross-section area and CS-szD been the two groups. However, the Ax-szW was significantly smaller in the dysmorphic pelvis group. In the S2 segment, the cross-section area, CS-szD, and Ax-szW were all significantly larger in the dysmorphic pelvis group. In the S3 segment, the cross-section area and CS-szD of the normal pelvis group were both significantly smaller. No differences were found in the Ax-szW between the two groups. Based on our findings in a Taiwanese population, S1 was the most suitable segment for transiliac-transsacral screw fixation in a normal pelvis, whereas S2, followed by S3, was most suitable in a dysmorphic pelvis. This study offers surgeons information on identifying the optimal sacral segment for transiliac-transsacral screw placement for each pelvic morphology. [Orthopedics. 2024;47(1):e13-e18.].

Clinical implications of additional posterior fractures in combined anterior-posterior pelvic ring fractures in elderly patients

ObjectivesHistorically, pelvic ring fractures (PRF) are considered to occur predominantly in the anterior ring and therfore to be mechanically stable. Combined anterior and posterior (A + P) PRF are expected to be less mechanically stable and therefore to be associated with higher levels of pain and reduced mobility compared to isolated anterior fractures. The current study investigates the clinical relevance of combined A + P PRF in elderly patients. MethodsA prospective multicentre cohort study was conducted in patients >70 years of age with anterior PRF after low-energy trauma diagnosed on conventional radiographs. All patients underwent an additional CT-scan. Patients were divided into two groups; isolated anterior or combined A + P fractures. Patients were treated conservatively with adequate analgesia for at least one week. If patients could not be mobilised after conservative treatment, surgical fixation was performed. Numerical Rating Scale (NRS) pain scores, dependence on walking aids and Activities of Daily Living scores (ADL) were measured at 2–4 weeks, and 3, 6 and 12 months after fracture. Results102 patients (age 81.1 ± 7.6 years) were included. Isolated anterior fractures were diagnosed in 25 (24.5%) and A + P fractures in 77 (75.5%) patients. Baseline characteristics did not differ between the two groups. Most patients were successfully treated conservatively and 5 (4.9%) underwent percutaneous trans-iliac, trans-sacral screw fixation after failure of conservative treatment. At 2–4 weeks post trauma, patients with A + P fractures had similar median pain scores (3 (range 0–8) vs. 5 (0–10), p = 0.19) and ADL scores (85 (25–100) vs. 78.6 (5–100), p = 0.67), but were more dependent on walking aids (92.8% vs. 72.2%; p = 0.02) compared to patients with isolated anterior fractures. There were no significant differences at 3 months. At one year follow-up the median NRS pain and ADL scores for both fracture groups were 0 and 100, respectively. Mortality was 10.8%, and additional loss to follow-up was 17.6%. ConclusionsThe vast majority of elderly patients with PRF have combined A + P fractures. The clinical implications of additional posterior pelvic ring fractures in elderly patients appears to be limited.

Causes of Increased Use of Closed Reduction and Internal Fixation for High-Energy-Related Traumatic Sacral Fractures

BackgroundReasons for the increased use of closed reduction and internal fixation (CRIF) for traumatic sacral fractures (SFs) are unclear in the literature. Therefore, we aimed to report the annual changes in the number of patients, mechanisms of injury, fracture patterns, and fixation methods.MethodsIn this retrospective study, we extracted data of 271 patients (mean age, 37.5 years) from the trauma register over an 8-year period. Annual records regarding the number of patients, injury mechanisms, fracture types, and treatment options were statistically analyzed to examine the interactions among these factors.ResultsThe number of patients with SFs increased significantly each year. The rate of admission to the intensive care unit after resuscitation was high (64.9%). Arbeitsgemeinschaft für Osteosynthesefragen (AO) type C pelvic ring injury (PRI), Dennis zone II injury, Roy-Camille type 2 injury, and U/H-type injury were the most common fracture types. Trans-iliac trans-sacral screws were mainly used in AO type B PRI, and their use significantly increased each year. For AO type C PRI, open reduction and internal fixation (ORIF) with rigid fixation was the main treatment, and the use of CRIF with iliosacral screws decreased each year. Stepwise statistical analysis revealed that the increase in AO type B PRI and ORIF for anterior PRI were the factors contributing to the increased use of CRIF for SFs.ConclusionsWhile the use of osteosynthesis for SFs is increasing, an increased use of CRIF for traumatic SFs has also been observed in clinical practice. This increase can be attributed to the increase in AO type B PRIs and ORIF for anterior PRIs.

Percutaneous screw fixation of the pubic symphysis versus plate osteosynthesis: a biomechanical study.

Objectives: To compare the stability of screw fixation with that of plate fixation for symphyseal injuries in a vertically unstable pelvic injury (AO/Tile 61-C1) associated with complete disruption of the sacroiliac joint and the pubic symphysis. Methods: Eight fourth-generation composite pelvis models with sacroiliac and pubic symphyseal disruption (Sawbones, Vashon Island, WA) underwent biomechanical testing simulating static single-leg stance. Four were fixed anteriorly with a symphyseal screw, and 4 with a symphyseal plate. All had single transsacral screw fixation posteriorly. Displacement and rotation were monitored at both sacroiliac joint and pubic symphysis. Results: There was no significant difference between the 2 groups for mean maximum force generated. There was no significant difference in net displacement at both sacroiliac joint and pubic symphysis. There was significantly less rotation but more displacement in the screw group in the Z-axis. The screw group showed increased stiffness compared with the plate group. Conclusions: This is the first biomechanical study to compare screw versus plate symphyseal fixation in a Tile C model. Our biomechanical model using anterior and posterior fixation demonstrates that symphyseal screws may be a viable alternative to classically described symphyseal plating.