Posterior Pelvic Ring Research Articles

The Utility of the Hyperinlet View in Posterior Fixation of Pelvic Ring Injuries.

Percutaneous pelvic fixation has evolved into a widely used, safe, and effective treatment option in the management of pelvic ring injuries. Proper preoperative and intraoperative radiographic evaluation of these injuries is critical to ensure safe placement of fixation of the pelvis. Traditional intraoperative views for posterior pelvic ring fixation include the pelvic inlet and outlet views. We propose that the intraoperative use of a hyperinlet view, which uses additional cranial tilt relative to the traditional inlet view, is helpful to better delineate the spinal canal and thereby better define the posterior limit of the osseous fixation pathway of the upper sacral segments. This study illustrates the use of this novel radiographic view and presents a patient cohort in which it was effectively used.

Posterior Pelvik Halka Yaralanmalarında Posterior Perkütan Transiliak Plak Tespiti Sonuçları

The diagnose and treatment of sacrum fractures are still difficult to manage. Various surgical methods have been reported for the treatment of sacral fractures in the literature. The aim of our study is to examine the functional results of patients treated with posterior percutaneous transiliac plate in our clinic. 56 patients who underwent surgical treatment for posterior pelvic ring injury between June 2013 and September 2020 and who had a minimum 6-month follow-up were retrospectively analyzed. Demographic data, radiological images, Pelvic Outcome Scores (POS) and Short Form-36 (SF-36) results in the 6th postoperative month were analyzed. When the POS data detected at the 6th month examination were examined, the mean pelvic outcome score was found to be 32 (26-37) and the SF-36 results as 80 (48-90). The mean duration of the surgical procedure was 32.2 minutes, and the median number of fluoroscopy shots taken during surgery was 2 (1-6). The functional results of the patients who underwent posterior percutaneous transiliac plate fixation were good at the6th month examinations. With this technique, it was observed that the operation time was short and fluoroscopy exposures were low. We believe that this technique, which has a short learning curve, can be used safely in sacrum surgery. For that reason, this method seems to be an easier and more convenient method for surgeons who are not experienced in pelvic surgery.

Minimally Invasive Percutaneous TightRope® System Fixation for an Unstable Posterior Pelvic Ring: Clinical Follow‐up and Biomechanical Studies

ObjectiveTo evaluate the mechanical stability and clinical efficacy of minimally invasive percutaneous TightRope® systems applied via gun‐shaped reduction forceps for unstable posterior pelvic ring fractures.Materials and methodsThis study consists of two parts: a clinical retrospective study and a randomized controlled biomechanical test. For the clinical study, a retrospective analysis of posterior pelvic ring fractures was performed between June 2015 and May 2020. Eighteen patients underwent surgery using two TightRope® systems to fix a broken posterior pelvic ring because of unstable AO type C1 and C2 pelvic ring fractures. The patients were followed up for at least 2 years, and all patients were evaluated using the Majeed scoring system and vertical displacement. In the biomechanical tests, six embalmed adult pelvic specimens were used. The fractures were subjected to TightRope®, IS screw, and TBP fixation in a randomized block design. The specimens were placed in a biomechanical testing machine in a standing neutral posture. A cyclic vertical load of up to 500 N was applied, and the displacement of the specimens was recorded by the testing machine. The ultimate load in each group of specimens was recorded. The displacement and ultimate load were compared and analyzed by statistical methods.ResultsAt a mean follow‐up of 38.89 ± 8.72 months, the functional Majeed score was excellent in 14 patients and good in four patients. The final radiological examinations showed that the outcome was excellent in 14 patients and good in four patients. In these patients, no serious clinical complications were found. Weight‐bearing was delayed in four patients. In biomechanical tests, the displacement of the specimens fixed with TightRope® was significantly lower than that of the specimens fixed with TBP (P < 0.05) when the load ranged from 300 to 500 N. The displacement in the IS screw group was significantly lower than that in either the TBP or TightRope® group (P < 0.05) when the load ranged from 0 to 500 N. The ultimate load in the IS screw group (1798 ± 83.53 N) was significantly greater than that in the TBP group (1352 ± 74.41 N) (t = 9.78, P < 0.0001) and the TightRope® group (1347 ± 54.28 N) (t = 11.11, P < 0.0001). However, no significant difference was observed between the TightRope® and TBP groups (t = 0.13, P = 0.90).ConclusionPercutaneous posterior TightRope® system shows strong stability in mechanical experiments and shows good results in clinical follow‐up while this system has certain advantages in lower surgical requirements and lower risk of related nerve and vascular structural damage.

Spinal nerve compression after malunion of vertical sacrum fractures.

Introduction and importanceUnstable pelvic ring injuries often occur in high energy traumas. Vertical sacrum fracture is an associated injury. This report describes a late spinal nerve compression that occurred following surgical reduction and fixation of pelvic ring injuries caused by traumatic L5-S1 disc herniation and malposition of the sacral fracture.Case presentationA 61-year-old female presented with radiculopathy in her right leg after surgical reduction and fixation of a sacral and pelvic fracture. Physical examination revealed numbness and weakness of the right leg. Radiographic studies showed spinal compression caused by a fracture spike from the malunion of the sacrum and protruding disc from the L5/S1 level. The fracture spikes were removed by laminectomy and discectomy after which the patient's condition had improved and she had no recurrent symptoms at the one-year follow-up.Clinical discussionMalunion of a posterior pelvic ring fracture and a herniated adjacent intervertebral disc can cause sacral nerve root compression. This complication can be managed and satisfactory results achieved by surgical intervention.ConclusionTraumatic L5-S1 disc herniation and malposition following surgical reduction and fixation of a sacrum fracture can be avoided. Posterior decompression by laminectomy and discectomy is an effective alternative treatment for patients with this condition.

Computer-aided automatic planning and biomechanical analysis of a novel arc screw for pelvic fracture internal fixation

Background and ObjectiveThe sacroiliac joint screw is a common fixation method for pelvic posterior ring fractures. The complex anatomical structure around the pelvis makes it impossible to find a suitable fixed path, which increases the difficulty of surgical operation. In this paper, we propose an automatic planning algorithm based on a computer-aided internal arc fixation channel for pelvic fractures for the first time. MethodsA channel generation algorithm based on seed derived points was designed, and the optimal channel was selected by scoring rules based on 3D erode algorithm for the generated channel. The biomechanical properties of the internal arc fixation screw and traditional internal straight fixation screw in three postures were compared using biomechanical finite element analysis. ResultsThe proposed algorithm verified the existence of a more adaptable internal arc fixation channel and can quantitatively plan a relatively optimal constant-curvature internal arc fixation channel in pelvises of ten adults. Significantly high stresses concentrated around the interaction region between the screws and bone may increase the risk of bone fractures and screw loosening in the long term. The experimental results show that the internal arc fixation screw has better strain and deformation performance than the internal straight fixation screw. ConclusionsA novel arc internal fixation method for pelvic fractures was proposed to improve the safety and stability of screw fixation of pelvic fracture. The nonparametric test proved that the sacroiliac dislocation model repaired by internal arc fixation screw was significantly different from that repaired by internal straight fixation screw. The computer-aided automatic planning algorithm provides the possibility of robot-assisted pelvic fracture fixation.

Biomechanical evaluation of seven fixation methods to treat pubic symphysis diastasis using finite element analysis

BackgroundPubic symphysis diastasis (PSD) hinders the connection between bilateral ischia and pubic bones, resulting in instability of the anterior pelvic ring. PSD exceeding 25 mm is considered disruptions of the symphyseal and unilateral/bilateral anterior sacroiliac ligaments and require surgical intervention. The correct choice of fixation devices is of great significance to treat PSD. This study aimed to evaluate the construct stability and implant performance of seven fixation methods to treat PSD using finite element analysis.MethodsThe intact skeleton-ligament pelvic models were set as the control group. PSD models were simulated by removing relevant ligaments. To enhance the stability of the posterior pelvic ring, a cannulated screw was applied in the PSD models. Next, seven anterior fixation devices were installed on the PSD models according to standard surgical procedures, including single plates (single-Plate group), single plates with trans-symphyseal cross-screws (single-crsPlate group), dual plates (dual-Plate group), single cannulated screws, dual crossed cannulated screws (dual-canScrew group), subcutaneous plates (sub-Plate group), and subcutaneous pedicle screw-rod devices (sub-PedRod group). Compression and torsion were applied to all models. The construct stiffness, symphyseal relative micromotions, and von Mises stress performance were recorded and analyzed.ResultsThe construct stiffness decreased dramatically under PSD conditions. The dual-canScrew (154.3 ± 9.3 N/mm), sub-Plate (147.1 ± 10.2 N/mm), and sub-PedRod (133.8 ± 8.0 N/mm) groups showed better ability to restore intact stability than the other groups (p < 0.05). Regarding regional stability, only single-plate fixation provided unexpected regional stability with a diastasis of 2.1 ± 0.2 mm (p < 0.001) under a compressive load. Under a rotational load, the single-crsPlate group provided better regional angular stability (0.31° ± 0.03°, p < 0.001). Stress concentrations occurred in the single-Plate, sub-Plate, and sub-PedRod groups. The maximum von Mises stress was observed in the single-plate group (1112.1 ± 112.7 MPa, p < 0.001).ConclusionThe dual-canScrew fixation device offers ideal outcomes to maintain stability and prevent failure biomechanically. The single-crsPlate and dual-Plate methods effectively improved single-Plate device to enhance regional stability and disperse stresses. The subcutaneous fixation devices provided both anterior pelvic ring stability and pubic symphysis strength.

Posterior INFIX for Treating Unilateral Unstable Sacral Fractures.

ObjectiveTo evaluate the clinical outcomes of the treatment of unilateral unstable sacral fractures by fixation with the posterior INFIX (posterior pelvic ring screw‐rod internal fxation).MethodsData of 60 patients with unilateral unstable sacral fractures who underwent surgery from March 2013 to March 2020 were retrospectively analyzed according to the selection criteria. All patients were associated with anterior pelvic ring injuries, and the operations were performed by the same team of surgeons. According to the different types of internal fixation, the patients were divided into two groups, which both included 30 patients: the posterior INFIX group and iliosacral screw fixation group. The demographic and clinical data of the two patient groups, such as age, sex, sacral fracture types based on the Denis classification, operation time, amount of intraoperative bleeding, intraoperative fluoros copy time, Majeed pelvic score at final follow‐up, and quality of fracture reduction based on Mears and Velyvis's imaging classification criteria were collected by the same researcher and compared statistically.ResultsAll patients were continuously followed up for 23.17 ± 3.34 months (range, 12 to 46 months). All sacral fractures healed with an average healing time of 9.3 ± 2.24 months (range, 6 to 18 months). None of the patients had re‐displacement of the fracture or fixation failure. Compared to the iliosacral screw group, the posterior INFIX group patients had more intraoperative bleeding (t = 3.59, P < 0.001), shorter operation time (t = 4.49, P < 0.001), and shorter intraoperative fluoroscopy time (t = 6.26, P < 0.001). There were no statistical differences between the two groups in terms of age, sex, fracture type, Majeed score, and quality of fracture reduction (P > 0.05). In the posterior INFIX group, one patient had a superficial wound infection and one patient complained of discomfort due to a prominent fixation. In the iliosacral screw fixation group, one patient had intraoperative iatrogenic S1 nerve injury and vessel injury. The posterior INFIX fixation was a simpler manipulation with higher safety, shorter time of operation and intraoperative fluoroscopy, and similar clinical outcomes compared to iliosacral screw fixation.ConclusionFor the treatment of unilateral unstable sacral fractures, the posterior INFIX fixation can be recommended in clinic application.

Vissage ilio-sacré des ruptures de l’anneau pelvien avec guide de forage tridimensionnel personnalisé

IntroductionPosterior pelvic ring disruption includes sacral fractures, sacroiliac joint fracture dislocations and ilium fractures. Percutaneous iliosacral screw fixation of sacral fractures and sacraoiliac joint fracture dislocations have been prevailing, it has the advantages of minimal invasiveness, less blood loss and low wound infection rate. HypothesisThis study was to evaluate the application of three-dimensional (3D) printed patient-specific guide template in closed reduction and iliosacral screw fixation of posterior pelvic ring disruption. Material and methodsThe data of patients, who were treated with closed reduction and iliosacral screw fixation of posterior pelvic ring disruption with the assistance of 3D printed guide template from December 2014 to September 2018, were collected. The screw placement time, fluoroscopy time, intraoperative blood loss, fracture reduction, screw position and functional assessment were recorded. ResultsThere were 17 cases of unstable pelvic fractures, and 20 screws were inserted for fixation of sacral fractures or sacroiliac joint dislocations, with bilateral screw placement in 3 cases. The average time for each screw placement was 45.9±8.6min (30–60min). The average fluoroscopy time for each screw insertion was 50.3±19.7s (24–96s). The mean blood loss for each screw placement was 32.0±11.1mL (20–50mL). According to Matta scale, the fracture reduction was graded as excellent in all the 17 cases. According to the modified Gras classification, the 3D CT reconstruction of the pelvis demonstrated grade 1 for 18 screws and grade 2 for 2 screw. Functional outcome 1 year postoperatively was rated as 15 excellent and 2 good, according to the Majeed functional scale. DiscussionIt is feasible and safe to stabilize the posterior pelvic ring disruption using iliosacral screw fixation under assistance of the 3D printed guide template. It could reduce fluoroscopy time, screw placement time and intraoperative blood loss and achieve good postoperative recovery. Level of proofIV; retrospective study.

The grade of instability in fragility fractures of the pelvis correlates with impaired early mobilization

PurposeThis study aimed to investigate whether gait patterns of patients with fragility fractures of the pelvis (FFP) comply with the grade of fracture instability, defined by radiological patterns.Patients and methodsThis prospective, single-center, observational study included 39 patients with an FFP. Gait analysis was performed with a wearable insole force sensor (Loadsol® by Novel, Munich, Germany) 4–7 days after admission. Patients were divided in two groups: Group A included FFP type 1 fractures, which affect the anterior pelvic ring only, Group B contained FFP type 2–4 fractures with an involvement of the posterior pelvic ring. Primary outcome parameter was the FTI ratio (force–time integral (N*s)).ResultsThe mean age was 85.08 years (SD ± 6.45), 94.9% (37/39) of the patients were female. The most common fracture type was an FFP 2b (64.1%, 25/39). Group A showed a significantly higher FTI ratio (45.12%, SD ± 4.19%) than Group B (38.45%, SD ± 5.97%, p = 0.002). Further, a significant correlation of the FTI ratio and the average (r = 0.570, p < 0.001) and maximum (r = 0.394, p = 0.013) peak force was observed.ConclusionThe gait pattern of patients with an FFP type 2–4 was more imbalanced than of patients with an FFP type 1 fracture. These findings match with the radiological classification of FFP, which indicates higher instability, when the posterior pelvis is affected. Gait analysis might offer earlier functional diagnostics and may accelerate the treatment decision with shorter periods of immobility in future. Especially in cross-border cases, early gait analysis could be beneficial to clarify the indication for or against surgery.

Pelvic ring injuries: classification and treatment

This review article will focus on the classification and treatment options for pelvic ring fractures. The pelvic ring can be split into anterior and posterior supporting structures. Injury can result in mechanical pelvic instability, the significance of which is determined by the magnitude and direction of forces applied during injury. The typical fracture patterns of anteroposterior compression, lateral compression and vertical shear form the basis of the Young and Burgess classification. However, the logic of the Tile classification system is useful in determining the degree of pelvic instability and the optimal surgical stabilization options. Posterior pelvic ring stabilization is often performed percutaneous after closed fracture reduction with sacro-iliac screws. This avoids the soft tissue complications often associated with open posterior approaches. Alternative reduction techniques can be performed through an open anterior approach using the first ilio-inguinal window to approach sacro-iliac joint disruptions as well as crescent fractures of the posterior iliac wing. The anterior pelvic ring, traditionally stabilized with external fixation, can be well accessed with the open ‘STOPPA’ approach. This allows access to an area extending from the pubic symphysis around the pelvic brim to the anterior aspect of the sacro-iliac joint where plates can be applied. Other options for anterior ring stabilization include column screws and the use of the ‘In-fix’ (Internal Fixator).

Preoperative CT simulation of iliosacral screws for treating unstable posterior pelvic ring injury

BackgroundThe percutaneous iliosacral screw is a common procedure for treating pelvic posterior ring instability. Traditional X-ray fluoroscopy screw placement has the advantages of decreased bleeding and trauma, but it also has some drawbacks, such as increased radiation exposure and screw dislocation. The purpose of this study was to establish a safe, effective, and quick approach for putting iliosacral screws for the treatment of unstable posterior pelvic ring damage utilizing simulated screws based on preoperative computed tomography (CT) planning.MethodsFrom February 2019 to June 2020, we retrospectively assessed 41 patients with posterior pelvic ring instability who were treated with percutaneous iliosacral screws in our institution, and randomly separated them into two groups: conventional surgery (n = 20) and preoperative planning (n = 21). Pelvic radiographs (anteroposterior, inlet, outlet), as well as normal CT scans of the pelvis, were all taken postoperatively to confirm the screw position. After that, the screw insertion time, the radiation exposure time, and the screw misplacement rate (as assessed by postoperative CT) were all examined. Screw position grading was evaluated by Smith grading.ResultsIn the conventional surgery group, 26 screws were inserted in 20 patients, with each screw insertion taking 23.15 ± 4.19 min and 1.02 ± 0.17 min to expose to radiation. Eight of the 26 screws were misplaced (30.8%). In the preoperative planning group, 24 screws were inserted in 21 patients, with each screw taking 19.57 ± 4.05 min to implant and 0.67 ± 0.09 min to expose to radiation. One of 24 screws was misplaced (4.2%). Screw insertion time, radiation exposure time, and screw dislocation rate were all significantly reduced when preoperative planning aided iliosacral screw placement (P < 0.05).ConclusionsPreoperative CT simulation of iliosacral screws for placement planning, screw trajectory, and intraoperative screw placement is a safe way for reducing surgical time, radiation exposure, and ensuring accurate screw placement.

Differences in Accuracy and Radiation Dose in Placement of Iliosacral Screws: Comparison between 3D and 2D Fluoroscopy.

Percutaneous iliosacral screw fixation is a widely accepted method of stabilizing the posterior pelvic ring. Recently developed tools such as 3D-navigated fluoroscopy and computed navigation seem to prevent a surgeon from conducting screw misplacement. The study aimed to comparatively assess the introduction of sacroiliac screw placement using 2D and 3D fluoroscopy in terms of accuracy and radiation exposure. Iliosacral screws were introduced in 37 patients using 2D (group N1) and in 36 patients using 3D fluoroscopy (group N2) techniques. Overall, 61 and 56 screws were introduced in groups N1 and N2, respectively. Screw placement accuracy was assessed using postoperative computed tomography and Smith’s scale. Intraoperative radiation exposure was also assessed. No differences were noted between groups in terms of screw positioning accuracy and radiation dose. Both 2D and 3D fluoroscopy provide good visualization for safely placing percutaneous iliosacral joint screws. Using 3D fluoroscopy-based navigation in comparison with 2D fluoroscopy is not advantageous.

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

ObjectivesFragility fractures of the pelvis (FFP) commonly occur in the frail elderly. Displacement in the posterior pelvic ring is recognized as the key sign of instability. This study aims to elucidate the relationship between computer tomography (CT)-based frailty markers and displacement of the posterior pelvic ring within 7 days after injury. MethodsThis retrospective study included 49 patients (42 females, 7 males) with FFP (type I 10, type II 24, type III 12, type IV 3). On a CT slice at the level of the third lumbar vertebra, skeletal muscle area, skeletal muscle radiation attenuation, and skeletal muscle index (SMI) were calculated as sarcopenia markers. Osteopenia was measured with trabecular region of interest attenuation technique on the same CT slice. ResultsThere was no difference in the demographics between non-displaced and displaced FFP. CT-based data showed that patients with FFP had osteopenia. However, no difference was found between non-displaced and displaced FFP. SMI was higher in FFP types III/IV than non-displaced FFP when CT-based data on sarcopenia were compared among all patients. Female patients with FFP demonstrated similar results. Logistic regression analysis using the demographics and CT-based markers on sarcopenia and osteopenia revealed that SMI was a potential determinant of displacement of the posterior pelvic ring fractures. ConclusionsThere was inverse association between sarcopenia and displacement of the posterior pelvic ring in the early phase of FFP. Relatively preserved muscle may develop displacement in the elderly with osteopenia.

Rectal avulsion associated with complex open pelvic fracture following rollover injury

Background: We present a rare case of complete rectal avulsion from the external anal sphincter complex associated with unstable pelvic ring disruption, including spinopelvic dissociation, following rollover by tractor. In the context of major pelvic trauma, evaluating for unstable bony, acute vascular, urethral and bladder injuries is essential. However, a detailed search for anorectal injury is also required by the reporting radiologist. Case Report: In this case report we highlight specific pelvic floor anatomy on CT, with a focus on gross morphology and the presence of peri-rectal free gas as primary evidence for injury. Secondary radiological evidence which should trigger the search for anorectal injury includes bony posterior pelvic ring disruption (sacrum or coccyx fractures) or associated Morel-Lavallee lesions. Conclusion: The presence of radiological abnormality should prompt direct clinical inspection for corroboration. Early recognition is crucial for joint colorectal and orthopaedic management and the avoidance of delayed pelvic sepsis, which may become intractable.

Starr frame-assisted minimally invasive internal fixation for pelvic fractures: Simultaneous anterior and posterior ring stability

ObjectiveWe aimed to investigate the surgical techniques, efficacy, and safety of Starr frame-assisted minimally invasive internal fixation for simultaneous anterior and posterior ring stability in pelvic fractures. MethodsThe clinical data of 22 patients with anterior and posterior pelvic ring injuries who underwent Starr frame-assisted minimally invasive internal fixation were retrospectively collected. The anterior pelvic ring was fixed with an anterior subcutaneous internal fixator (INFIX), and the posterior pelvic ring was fixed with sacroiliac screws. The operative time, intraoperative blood loss, fluoroscopy times, number of assistants, complications, and weight-bearing time were analyzed. The Matta score was used to evaluate the fracture reduction. The Majeed score was used to evaluate clinical efficacy, and Gibbon's classification was used to estimate the occurrence of sacral nerve injury. ResultsAll 22 patients were treated with sacroiliac screws for posterior ring injuries, including 12 cases with single sacroiliac screws, nine with two sacroiliac screws, and one with three sacroiliac screws. INFIX was used for all anterior ring fixation, including two screws in seven cases, three screws in 13 cases, and four screws in two cases. The fracture reduction quality was excellent in 15 cases, good in four cases, and moderate in three cases by Matta scores. All patients were followed up for 6–20 (12.5 ± 5.7) months. Callus-formation time based on postoperative X-ray was 3–8 (4.3 ± 1.2) weeks. Weight-bearing time was 3–12 (6.3 ± 2.8) weeks after surgery. At the last follow-up, 15 patients were evaluated as excellent, five as good, and two as fair according to the Majeed score. Gibbons’ classification showed that one of the three patients with sacral nerve injury recovered completely and two did not recover. Complications occurred in six patients, including one with internal fixation loosening, two with anterolateral thigh paresthesia, one with malunion, one with nonunion, and one with heterotopic ossification. ConclusionsStarr frame-assisted minimally invasive internal fixation could stabilize the anterior and posterior pelvic rings simultaneously, overcoming the difficulty of fracture reduction. This technique can help patients with early postoperative weight-bearing and improved functional outcomes, providing a novel modality for the minimally invasive treatment of pelvic ring injuries.

What happens at the L5/S1 facet joint when implants are placed across the sacroiliac joint?

BackgroundInjuries to the posterior pelvic ring are often stabilized with fixation across the sacroiliac joint (SIJ). However, the compensatory changes at the neighboring L5/S1 facet joint are unknown. The objective of this study was to determine the compensatory change in pelvic kinematics and contact forces at the L5/S1 facet joint after fixation across the sacroiliac joint (SIJ) using a cadaveric model. MethodsFive fresh-frozen cadaveric pelvis specimens were dissected to remove non-structural soft tissue. Retroreflective markers were fixed to the L5 body, S1 body and bilateral anterior superior iliac spines to represent the motion of L5, S1 and the ileum, respectively. Pressure sensors were inserted in both L5/S1 facet joints. Testing was performed using a robotic system that applied load to mimic ambulation. Testing was performed prior to SIJ fixation, after unilateral SIJ fixation and bilateral fixation. ResultsContact force at the L5/S1 facet joint significantly increased by 55% from 48.4 N to 75.2 N following unilateral fixation (p = 0.0161) and increased by 100% to 96.9 N after bilateral fixation (p = 0.0038). Unilateral SIJ fixation increased flexion of the ilium relative to L5 from 1.2° to 2.0° (p = 0.01) and increased axial rotation of L5 relative to S1 from 0.7° to 1.6° (p = 0.001). Bilateral fixation increased flexion of the ilium relative to L5 to 2.0° from 1.2° prior to fixation (p = 0.001), increased axial rotation of L5 relative to S1 to 1.2° from 0.7° prior to fixation (p = 0.002) and increased flexion of L5 relative to S1 to 2.4° from 1.5° prior to fixation (p = 0.04). ConclusionThe L5/S1 facet joint experiences compensatory increased motion under increased contact force after unilateral and bilateral SIJ fixation, possibly predisposing it to adjacent segment arthritis. Level of EvidenceV, cadaveric study

Effect of Percutaneous Posterior Pelvic Ring Reduction and Fixation on Patient-Reported Outcomes.

The purpose of this study was to assess patient outcomes using Patient-Reported Outcomes Measurements Information System (PROMIS) scores after closed reduction and percutaneous fixation (CRPF) of the posterior pelvic ring and determine whether quality of reduction affects the outcomes. This is a retrospective cohort study. The study involved a Level I trauma center. The study included 46 adult patients with operatively treated pelvic ring injuries (63% OTA/AO 61-B) who underwent CRPF between 2014 and 2018 at a single institution. The intervention involved closed reduction and percutaneous posterior pelvic ring fixation. The main outcome measurements were postoperative patient PROMIS scores, including physical function, pain interference, anxiety, and depression, and radiographic measurements of postoperative displacement and pelvic deformity. After CRPF, PROMIS scores of physical function, pain interference, and anxiety were significantly improved at the time of final follow-up when compared with the first postoperative visit. The amount of malreduction or pelvic deformity did not significantly affect outcome scores; however, results were limited by small sample size. CRPF of posterior pelvic ring injuries results in good functional and radiographic outcomes. Degree of malreduction may not affect outcomes as much as previously believed. Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Iliosacral screw fixation of pelvic ring disruption with tridimensional patient-specific template guidance

IntroductionPosterior pelvic ring disruption includes sacral fractures, sacroiliac joint fracture dislocations and ilium fractures. Percutaneous iliosacral screw fixation of sacral fractures and sacraoiliac joint fracture dislocations have been prevailing, it has the advantages of minimal invasiveness, less blood loss and low wound infection rate. HypothesisThis study was to evaluate the application of three-dimensional (3D) printed patient-specific guide template in closed reduction and iliosacral screw fixation of posterior pelvic ring disruption. Material and methodsThe data of patients, who were treated with closed reduction and iliosacral screw fixation of posterior pelvic ring disruption with the assistance of 3D printed guide template from December 2014 to September 2018, were collected. The screw placement time, fluoroscopy time, intraoperative blood loss, fracture reduction, screw position, and functional assessment were recorded. ResultsThere were 17 cases of unstable pelvic fractures,and 20 screws were inserted for fixation of sacral fractures or sacroiliac joint dislocations, with bilateral screw placement in 3 cases. The average time for each screw placement was 45.9±8.6min (30–60min). The average fluoroscopy time for each screw insertion was 50.3±19.7s (24–96 s). The mean blood loss for each screw placement was 32.0±11.1ml (20–50ml). According to Matta scale, the fracture reduction was graded as excellent in all the 17 cases. According to the modified Gras classification, the 3D CT reconstruction of the pelvis demonstrated Grade 1 for 18 screws and Grade 2 for 2 screw. Functional outcome 1 year postoperatively was rated as 15 excellent and 2 good, according to the Majeed functional scale. DiscussionIt is feasible and safe to stabilize the posterior pelvic ring disruption using iliosacral screw fixation under assistance of the 3D printed guide template. It could reduce fluoroscopy time, screw placement time and intraoperative blood loss and achieve good postoperative recovery. Level of proofIV; Retrospective study.

Displaced posterior pelvic ring fractures treated with an unlocking closed reduction technique: Prognostic factors associated with closed reduction failure, reduction quality, and fixation failure

PurposesThis study aimed to evaluate the clinical effect of the unlocking closed reduction technique (UCRT) for the displaced posterior pelvic ring fractures and to analyze the factors associated with failure of closed reduction and fixation. Patients and methodsData from patients admitted with displaced posterior pelvic ring fractures initially treated with the URCT from July 2017 to January 2020 were extracted. Clinical and radiological factors including fracture classification, interval days from injury to surgery, number of screws, and type of fixation for the posterior pelvic ring were analyzed to evaluate their correlation with closed reduction failure, reduction quality, and fixation failure. Then a logistic regression model was used for statistical analysis to eliminate confusion factors. ResultsNinety-seven patients with displaced posterior pelvic ring fractures were followed for a mean of 1.7 years after surgery. Successful closed reduction and percutaneous fixation were achieved for 89 patients (91.8%), of which 82 patients (92.1%) achieved an excellent or good reduction. Closed reduction failure which converted to open reduction was recorded for eight patients (8.2%). AO/OTA type C3 fracture (p = 0.036) and osteoporosis (p = 0.012) were significant factors for closed reduction failure. Excellent was recorded for 76 patients (78.4%) and acute (1-21 days) interval days from injury to surgery was an associated factor for reduction quality. For AO/OTA type C1 fractures, no more than two short screws (unilateral iliosacral screws) or a single long screw (transiliac-transsacral screws) were independent prognostic factors of fixation failure (p = 0.026). ConclusionsDisplaced posterior pelvic ring fractures treated with the UCRT are associated with excellent/ good radiological results. However, in patients with AO/OTA type C3 pelvic fracture and osteoporosis, the backup plan of open reduction should be routinely prepared. The patient should be brought to the operating room within three weeks to get a good reduction result. Two long screws or one long screw combined with two short screws are required to create a strong construct for AO/OTA type C1 pelvic fractures.

Clinical Analysis of Single and Double Sacroiliac Screws in the Treatment of Tile C1 Pelvic Fracture.

We investigated the difference between fixation of single and double sacroiliac screws in the treatment of Tile C1 pelvic fractures. The data of 54 patients with Tile C1 pelvic fractures who were admitted to the trauma center of the Red Society Hospital Affiliated to Xi'an Jiaotong University between August 2016 and August 2020 were retrospectively analyzed. All patients with posterior pelvic ring injuries underwent fixation with sacroiliac screws assisted by a percutaneous robotic navigation system. The operative time, amount of intraoperative blood loss, and postoperative follow-up time between the two groups (single sacroiliac and double sacroiliac screw groups) were compared. The Matta and Majeed scores at the last follow-up were compared between the groups to evaluate fracture reduction and functional recovery. Forty-nine patients were followed up for 17.2 (±4.5) months and 16.2 (±3.4) months in the single and double sacroiliac screw groups, respectively. All patients had excellent fracture reduction immediately after surgery, according to the Matta score. All fractures healed without complications. There was no statistically significant difference in preoperative general information, amount intraoperative blood loss, intraoperative anterior ring fixation method, and postoperative follow-up time between the two groups (P > 0.05). The operative time of the single sacroiliac screw group was shorter than that of the double sacroiliac screw group (P < 0.05). At the last follow-up, the Matta score of the double sacroiliac screw group was significantly better than that of the single sacroiliac screw group (P < 0.05), and there was no statistically significant difference in the Majeed functional scores (P > 0.05). For Tile C1 pelvic fractures, double sacroiliac screw fixation of posterior ring injuries can provide a more stable treatment with no statistically significant difference in functional recovery.