Ramus Screw Research Articles

Comparative study on anterior pelvic plating and pubic ramus screw fixation for straddle fracture: a matched-pair outcome analysis.

Straddle fractures involving both the superior and inferior rami often require surgical fixation due to instability. This study compared the clinical and radiological outcomes of pubic ramus screw fixation (PRSF) and anterior pelvic plating (APP) for the treatment of these fractures to identify the superior method. A retrospective analysis was conducted on 70 patients (37 males, 33 females; average age 47.6 years) treated surgically for straddle fractures at two Level 1 trauma centres between May 2017 and August 2022. The patients were divided into two groups, where 26 underwent PRSF and 44 underwent APP. The groups were matched based on preoperative characteristics such as age, sex, body mass index, injury mechanism, and severity. The key variables analysed included operation time, blood transfusion volume, early weight-bearing capability, and complication and reoperation rates. After matching, PRSF was associated with a shorter operative time (71.0min vs. 118.3min for APP, p < 0.0009) and lower blood transfusion requirements (0 units vs. 1 unit, p < 0.0001). Postoperatively, 61.5% of PRSF patients tolerated early weight-bearing, compared to none in the APP group. However, in two cases, PRSF could not be performed due to severe comminution or anatomical limitations, necessitating conversion to APP. Complication rates were similar between the groups (30.8% for PRSF vs. 27.3% for APP, p = 0.93). PRSF demonstrated advantages, such as shorter operative time, reduced blood transfusions, and earlier weight-bearing. However, APP remains valuable for complex fracture patterns. Treatment should be individualized based on fracture complexity and patient-specific factors to optimize outcomes.

Dependable Automated Approach for Measuring the Retrograde Superior Ramus Screw Corridor in Pelvic Fracture Fixation.

Precise measurement of the intraosseous corridor within the superior pubic ramus is essential for the accurate percutaneous placement of a retrograde superior ramus screw (SRS). However, conventional manual measurement methods are often subjective, leading to variations in results among observers. Our goal was to develop an automated and dependable method for determining the retrograde SRS corridor. We developed an automated technique that utilized a computed tomography (CT) image-based search algorithm to identify the retrograde SRS corridor with the maximum diameter. We evaluated the reliability of this automated approach in comparison to a manual method using 17 pelves. Subsequently, we used both methods to measure the diameter, length, and orientation of the retrograde SRS corridor in 204 pelves in a Chinese population and assessed the intra- and interobserver agreement of each method by calculating the root-mean-square error (RMSE) and constructing Bland-Altman plots. We determined the screw applicability (percentages of hemipelves that could be treated with specific sizes of screws) for each method. Additionally, we investigated potential factors influencing the corridor, such as sex, age, height, and weight, through regression analysis. The intra- and interobserver intraclass correlation coefficients (ICCs) for the automated method (0.998 and 0.995) were higher than those for the manual approach (0.925 and 0.918) in the assessment of the corridor diameter. Furthermore, the diameter identified by the automated method was notably larger than the diameter measured with the manual method, with a mean difference and RMSE of 0.9 mm and 1.1 mm, respectively. The automated method revealed a significantly smaller corridor diameter in females than in males (an average of 7.5 and 10.4 mm, respectively). Moreover, use of the automated method allowed 80.6% of the females to be managed with a 4.5-mm screw while a 6.5-mm screw could be utilized in 19.4%, surpassing the capabilities of the manual method. Female sex had the most substantial impact on corridor diameter (β = -0.583). The automated method exhibited better reliability than the manual method in measuring the retrograde SRS corridor, and showed a larger corridor diameter for screw placement. Females had a significantly smaller corridor diameter than males. Given the intricate nature of the automated approach, which entails utilizing different software and interactive procedures, our current method is not readily applicable for traumatologists. We are working on developing integrated software with the goal of providing a more user-friendly solution for traumatologists in the near future. Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.

The “Metaizeau trick” to facilitate medullary pubic ramus screw insertion: A technical note

Minimally invasive procedures have recently seen an increase in the treatment of pelvic ring disruptions and select acetabular fractures. Similar to ilio-sacral screws, the superior pubic ramus screw is becoming a preferred method for treating unstable pelvic ring fractures. While the osteology of the superior pubic ramus is well understood and has inherent variability, standard screw insertion techniques work effectively in most cases. If the anatomy prevents the standard approach, there are alternative methods that can be employed for successful screw placement, or there might be a need for an open reduction and internal fixation with plates. Such techniques can be material-intensive and time-consuming. In this paper, we introduce a straightforward method that utilizes the Metaizeau nail as a guide wire to facilitate screw insertion in most instances, termed the “Metaizeau trick”. Metaizeau nails, commonly found in trauma centers, are designed to locate a pathway effortlessly using this method. Level of evidenceIV.

Union and displacement characteristics following percutaneous screw fixation of superior pubic rami fractures.

To determine union and displacement metrics following percutaneous screw fixation (antegrade or retrograde) of superior pubic rami fractures. This is a retrospective cohort study from a single level 1 trauma center. Skeletally mature patients with at least one superior pubic ramus fracture present as part of a lateral compression-type pelvic ring injury were included. Eighty-five (85) patients with 95 superior pubic rami fractures met the study's inclusion criteria. LC1, LC2, and LC3 injuries occurred in 76.5%, 15.3%, and 8.2% of patients, respectively. The majority of patients underwent concurrent posterior pelvic ring fixation (94.1%). Superior ramus screw placement occurred predominantly via retrograde technique (81.1%) with cannulated screws of size 6.5mm or larger (93.7%). Of the 95 eligible fractures, 90 (94.7%) achieved union at a mean of 14.0weeks (7-40weeks). Of these united fractures, 69 (76.7%) healed with no measurable displacement, while the remaining 23.3% healed with residual mean displacement of 3.9mm (range: 0.5-9.0mm). Multivariable analysis demonstrated a positive association between age (p = 0.04) and initial displacement (p = 0.04) on the final degree of residual displacement at union. A Kaplan-Meier survival analysis identified increased age to be significantly related to increased time to union (X2 (2) = 21.034, p < 0.001). Union rates following percutaneous screw fixation of superior pubic rami fractures associated with lateral compression-type pelvic ring injuries approach 95%. Though minimal in an absolute sense, increasing age and a greater degree of initial displacement may influence the final degree of residual displacement at union. IV.

A Novel Implant for Superior Pubic Ramus Fracture Fixation-Development and a Biomechanical Feasibility Study.

Background and Objectives: Pubic ramus fractures are common in compound pelvic injuries known to have an increased rate of morbidity and mortality along with recurrent and chronic pain, impeding a patient's quality of life. The current standard treatment of these fractures is percutaneous screw fixation due to its reduced risk of blood loss and shorter surgery times. However, this is an intricate surgical technique associated with high failure rates of up to 15%, related to implant failure and loss of reduction. Therefore, the aim of this biomechanical feasibility study was to develop and test a novel intramedullary splinting implant for fixation of superior pubic ramus fractures (SPRF), and to evaluate its biomechanical viability in comparison with established fixation methods using conventional partially or fully threaded cannulated screws. Materials and Methods: A type II superior pubic ramus fracture according to the Nakatani classification was created in 18 composite hemi-pelvises via a vertical osteotomy with an additional osteotomy in the inferior pubic ramus to isolate the testing of three SPRF fixation techniques performed in 6 semi-pelvises each using either (1) a novel ramus intramedullary splint, (2) a partially threaded ramus screw, or (3) a fully threaded ramus screw. Results: No significant differences were detected among the fixation techniques in terms of initial construct stiffness and number of cycles to failure, p ≥ 0.213. Conclusion: The novel ramus intramedullary splint can be used as an alternative option for treatment of pubic ramus fractures and has the potential to decrease the rate of implant failures due to its minimally invasive implantation procedure.

A biomechanical comparison of superior ramus plating versus intramedullary screw fixation for unstable lateral compression pelvic ring injuries,,,

IntroductionManagement of the anterior component of unstable lateral compression (LC) pelvic ring injuries remains controversial. Common internal fixation options include plating and superior pubic ramus screws. These constructs have been evaluated in anterior-posterior compression (APC) fracture patterns, but no study has compared the two for unstable LC patterns, which is the purpose of this study. MethodsA rotationally unstable LC pelvic ring injury was modeled in 10 fresh frozen cadaver specimens by creating a complete sacral fracture, disruption of posterior ligaments, and ipsilateral superior and inferior rami osteotomies. All specimens were repaired posteriorly with two fully threaded 7 mm cannulated transiliac-transsacral screws through the S1 and S2 corridors. The superior ramus was repaired with either a 3.5 mm pelvic reconstruction plate (n = 5) or a bicortical 5.5 mm cannulated retrograde superior ramus screw (n = 5). Specimens were loaded axially in single leg support for 1000 cycles at 400 N followed by an additional 3 cycles at 800 N. Displacement and angulation of the superior and inferior rami osteotomies were measured with a three-dimensional (3D) motion tracker. The two fixation methods were then compared with Mann-Whitney U-Tests. ResultsRetrograde superior ramus screw fixation had lower average displacement and angulation than plate fixation in all categories, with the motion at the inferior ramus at 800 N of loading showing a statistically significant difference in angulation. ConclusionAlthough management of the anterior ring in unstable LC injuries remains controversial, indications for fixation are becoming more defined over time. In this study, the 5.5 mm cannulated retrograde superior ramus screw significantly outperformed the 3.5 mm reconstruction plate in angulation of the inferior ramus fracture at 800 N. No other significance was found, however the ramus screw demonstrated lower average displacements and angulations in all categories for both the inferior and superior ramus fractures.

Superior Pubic Ramus Screw Placement During Complex Acetabular Revision: Acetabular Distraction for Treatment of Pelvic Discontinuity.

With the patient in the lateral decubitus position, the acetabulum is exposed from a standard posterior approach for a revision THA. The location of the superior pubic root is identified after making a recess within the anteroinferior capsule. In order to ensure that the appropriate trajectory is obtained, C-arm imaging (inlet view and orthogonal obturator outlet views) is utilized to safely predrill the screw trajectory into the superior pubic ramus. A Kirschner wire (K-wire) is then placed into the hole. With use of a metal-cutting burr on the back table, customized peripheral screw holes are placed and then the acetabular component is slid and impacted into place over the K-wire. After cup insertion, the K-wire is removed and the superior pubic ramus screw can be placed and confirmed on fluoroscopy. In general, chronic pelvic discontinuity requires surgical management with revision THA and has historically employed the use of a cup-cage construct, custom triflange implants, and/or jumbo acetabular cups with modular porous metal augments1-5. With these treatment options, it is typically necessary to insert "kickstand" screws, which function to prevent abduction failure of the acetabular cup4,5. However, in many cases of discontinuity, there may be severe ischial osteolysis, making ischial screw placement difficult or impossible. The superior pubic ramus, however, remains a reliable option that can be utilized for inferior screw fixation, even in cases of severe acetabular bone loss, and thus is especially beneficial in these difficult cases. The technique of acetabular distraction was developed because of limitations with alternative techniques. This procedure achieves cementless biologic fixation and eventual discontinuity healing as a result of lateral or peripheral acetabular distraction and resultant medial or central compression across the pelvic discontinuity. Acetabular distraction allows for intraoperative customization and cement unitization of the acetabular construct. This procedure requires the use of a "kickstand" screw or of inferior screw fixation in order to prevent abduction failure of the cup. These screws may be placed into either the ischium or superior pubic ramus. If the patient has substantial ischial osteolysis, ischial screw fixation may not be possible. If not placed in a systematic manner, pubic ramus screws can be technically challenging, and incorrect placement can result in neurovascular injury. The present video article demonstrates a reproducible technical method for safely placing a screw in the superior ramus to aid in optimal fixation of the acetabular component in cases of pelvic discontinuity. Thus far, short-term survivorship of acetabular distraction with use of a jumbo cup and kickstand screws has been about 95%. In the largest study to date assessing patients with chronic pelvic discontinuity who underwent revision THA with use of the acetabular distraction technique, only 1 of 32 patients required revision for aseptic loosening6. An additional 2 patients had evidence of radiographic loosening but did not undergo revision, and 3 had migration of the acetabular component into a more stable configuration. Radiographically, 22 of 32 patients in the study demonstrated healing of the discontinuity6. In another study assessing the survivorship of porous tantalum acetabular shells in revision THA to treat severe acetabular defects, patients with inferior screw fixation with superior pubic ramus or ischial screws had a significantly lower incidence of proximal translation of components compared with those without inferior screw fixation7. For reproducible, successful execution of this technique, it is important to confirm correct placement of the acetabular retractors at the correct anatomical locations to ensure adequate surgical visualization of the acetabulum for easy identification of the superior pubic root.It is also critical to check placement of the drill via fluoroscopy with an inlet and obturator outlet views prior to drilling.The drill should be advanced on the oscillate setting to avoid inadvertently perforating the cortical bone and damaging surrounding neurovascular structures. OR = operating roomf/u = follow-upvac = vacuum-assisted closureRSA = radiostereometric analysis.

Percutaneous screw fixation assisted by hollow pedicle finder for superior pubic ramus fractures

BackgroundPubic ramus fracture was an injury of anterior pelvic ring, the anterior pelvic ring plays an important role in maintaining the stability of the pelvis. The purpose of this study was to investigate the effect and indication of percutaneous retrograde pubic screw fixation assisted by hollow pedicle finder for pubic ramus fractures.MethodsThe clinical data of 68 patients with pubic ramus fracture treated with cannulated screw from March 2008 to March 2020 were retrospectively analyzed. According to the surgical methods, they were divided into traditional surgery group (32 cases in group A, with traditional retrograde pubic screw fixation) and modified surgery group (36 cases in group B, with percutaneous retrograde pubic screw fixation assisted by hollow open circuit device). Operation time, blood loss, incision length, screw length and complications were recorded and compared between the two groups. On the second day after surgery, the maximum fracture displacement over plain radiographs, entrance radiographs and exit radiographs of the pelvis was evaluated according to Matta criteria to evaluate the postoperative fracture reduction. Majeed score was used to evaluate the hip function at 12 months after surgery.ResultsThe operations were successfully completed in both groups. The operation time, blood loss and incision length in group B were significantly less than those in group A (P < 0.05). There was no significant difference in screw length between the two groups (t = 0.797, P = 0.431). All patients were followed up for 8–38 months (mean 21.8 months). There were no vascular and nerve injury, fracture of internal fixator, screw entry into joint cavity, fracture nonunion and other complications in both groups. The fracture healing time of the two groups was 23.1 ± 2.1 weeks in group A while 22.7 ± 2.1 weeks in group B, respectively, and there was no statistical difference in the fracture healing time between the two groups (P > 0.05). In group A, there were 3 cases of incision infection, 1 case of incision fat liquefaction and 2 cases of lower extremity deep venous thrombosis, and the complication rate was 18.8%. There was only 1 case of lower extremity deep vein thrombosis in group B, and the complication rate was 2.8%, which was significantly lower than that in group A. The fracture in one case after surgery was found to be displaced in group A and no fracture was found in group B. There was no significant difference between the two groups in Matta imaging evaluation on the next day after surgery and Majeed function evaluation at 12 months after surgery (P > 0.05).ConclusionPercutaneous retrograde pubic ramus screw fixation assisted by hollow pedicle finder is effective in the treatment of pelvic pubic ramus fracture. It has the advantages of less incision, shorter operation time, less blood loss and lower incidence of complications compared with traditional methods. However, correct surgical indications should be required when we apply this surgical method.

Factors Associated With Failure of Superior Pubic Ramus Screws.

Examine factors associated with fixation failure in patients treated with superior intramedullary ramus screws. Retrospective. Single, Level 1 trauma center. Unstable pelvic ring fractures amenable fixation that included superior intramedullary ramus screws. Percutaneously inserted intramedullary superior ramus screw fixation of superior pubic ramus (SPR) fractures. Loss of reduction (LOR) of the SPR fracture defined as >2 mm displacement on pelvic radiographs at any time point in follow-up. Two hundred eighty-five fractures in 211 patients (age 44, 95% confidence interval 40.8%-46.4%, 59.3% women, 55.1% retrograde screws) were included in the analysis. 14 (4.9%) of fractures had LOR. Patients were significantly more likely to have LOR as age increased (P = 0.01), body mass index (BMI) increased (P = 0.01), and if they were women (P < 0.01). There was a significantly decreased LOR (P < 0.01) as fractures moved further from the pubis symphysis. Retrograde screws were significantly (P < 0.01) more likely to have LOR. In SPR fractures treated with retrograde screws, failure was significantly associated with increasing BMI (P = 0.02), the presence of an inferior ramus fracture (P = 0.02), and trended toward significance with increasing age (P = 0.06), and decreased distance from the symphysis (P = 0.07). Superior ramus screws are associated with a low failure rate (4.9%), which is lower than previously reported. Retrograde screw insertion, distance from the symphysis, increasing age, increasing BMI, decreased distance from the symphysis, and ipsilateral inferior ramus fractures were predictors of failure. In these patients, alternative modalities should be considered, although low rates of failure can still be expected. Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Low Superior Pubic Ramus Screw Failure Rate With Combined Anterior and Posterior Pelvic Ring Fixation.

To determine whether fracture pattern, implant size, fixation direction, or the amount of posterior pelvic ring fixation influences superior ramus medullary screw fixation failure. Retrospective cohort review. Regional Level 1 trauma center. After exclusion criteria, 95 patients with 111 superior ramus fractures with 3 months minimum follow-up were included. All patients underwent anterior and posterior pelvic ring fixation. Comparison of immediate postoperative radiographs and/or computer tomography scan with the latest postoperative image to calculate interval fracture displacement and implant position. Postoperative fracture displacement or implant position change greater than 1 cm were considered fixation failures. Five screws were defined as failures (4.5%), including 3 retrograde, 3 with bicortical fixation, 4 with a 4.5-mm screw, and 1 with a 7.0-mm screw. Fracture patterns included 2 oblique and 3 comminuted fractures. Based on the Nakatani classification, there were 3 zone II, 1 zone I, and 1 zone III. Failure modes included 3 with cut-out along the screw head and 1 cut-out and 1 cut-through at the screw tip. Our incidence of superior pubic ramus intramedullary screw fixation failure was 4.5%. Even with anterior and posterior fixation along with precise technique, failures still occur without a common failure predictor. The percutaneous advantages and proven strength provided by an intramedullary implant make it desirable to help reestablish global pelvic ring stability. Biomechanical and clinical studies are needed to further understand intramedullary superior ramus screw fixation. Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Biomechanical Analysis of Retrograde Superior Ramus Screw Fixation Constructs.

To investigate the biomechanical performance of different size and length retrograde superior ramus screws. A vertical superior ramus fracture was created in osteoporotic composite hemipelvis bone models (Sawbones, Vashon Island, WA). After reduction, 4 fixation groups were created by inserting either a solid 4.5 mm (Depuy Synthes, Paoli, PA) or cannulated 7.0 mm screw (Zimmer, Warsaw, IN) of either 80 mm (short) or 140 mm (long) in length. An intact and an unstabilized osteotomy group were also created. Samples underwent cyclic loading for 5000 cycles with data acquisition at regular intervals. At the end of cyclic loading, load to failure was performed. The displacement after 5000 cycles for 4.5 mm short screws was significantly greater than 4.5 mm long and 7.0 mm short screws. At 5000 cycles, the 4.5-mm short screws had a significantly lower stiffness and lower load to failure than all other screws and were not different from the osteotomy model. Short 4.5-mm screws demonstrated increased displacement, lower stiffness, and decreased load to failure compared with all other screws. The biomechanical performance of 4.5-mm short screws was no different than unstabilized controls. Longer bicortical screw fixation is suggested when possible. Additional biomechanical and clinical studies are needed to fully understand the significance of these findings.

Up-to-Date Approach in the Treatment of Impacted Mandibular Molars: A Literature Review.

Eruption problems in the mandibular molars are rare, but they have to be diagnosed and treated early. Treatment of impacted molars is challenging due to a limited access and complexity of the mechanics that needs to be applied. Methods for managing impacted or tilted mandibular molars include orthodontic repositioning, surgical uprighting, and extraction with or without transplantation of the third molar into the extraction site. This review highlights the methods and clinical procedures of surgical and orthodontic uprighting procedures of mandibular molars with different degrees and levels of impaction. It further discusses the use of the ramus screw as a temporary anchorage device in the uprighting of horizontally impacted mandibular molars.

Distance Between Reproductive Structures and the Insertion Point of the Retrograde Pubic Ramus Screw.

To identify the distance between the guidewire for a retrograde pubic ramus screw and critical reproductive structures in men and women. Twenty hemipelves from 10 fresh-frozen cadavers (pelvis to distal femur) were studied. The mean (±SD) age was 77 ± 6 years for the 5 male cadavers and 71 ± 9 years for the 5 female cadavers. A 2.8-mm guidewire for a cannulated screw was inserted from the parasymphyseal bone using fluoroscopic guidance. The soft tissue was dissected and measurements performed by the first author. In men, we measured the closest distances from the guidewire entry point to the contralateral spermatic cord and corpus cavernosum. In women, we measured the closest distances from the guidewire entry point to the base of the clitoral body and clitoral glans. In male cadavers, mean distances were 8.8 ± 4.2 mm to the spermatic cord and 13 ± 6.7 mm to the corpus cavernosum. The guidewire did not penetrate these structures in any specimen. In female cadavers, mean distances were 12 ± 5.7 mm to the base of the clitoral body and 40 ± 8.2 mm to the clitoral glans. The guidewire also did not penetrate these structures. The contralateral spermatic cord and corpus cavernosum in men and the base of the clitoral body in women are close to the pathway of the retrograde ramus screw guidewire. Careful identification of the entry point and avoidance of multiple attempts of guidewire insertion may reduce the risk of injury to these structures.

Open Rigid Internal Fixation of Low-Neck Condylar Fractures of the Mandible: Mechanical Comparison of 16 Plate Designs.

Background: In the literature, no information on plates for low-neck mandibular condylar osteosynthesis can be found, despite the fact that 30 plate designs have already been published. The aim of this study was to compare any dedicated plates for possible use in low-neck condylar fracture osteosynthesis. Methods: The force required for 1-mm displacement of the fixed fracture fragments and incidents of screw loosening were recorded on polyurethane mandibles among 16 designs of titanium plates fixed by 6-mm screws in a 2.0 system. Results: Double-straight plate fixation was the mechanical gold standard (15.2 ± 3.5 N), followed by A-shape Condylar Plates (14.9 ± 2.1 N), X-shape Condylar Plates (14.2 ± 1.3 N) and Auto Repositioning Plates (11.8 ± 2.4 N). Screw loosening was uncommon, as a minimum of three screws were placed into the condylar part. Fewer screws were lost from the ramus part of the fixation if the plate was attached to the condylar part by three screws. Often, the stability of the ramus screws was lost when there were only two fixing screws in the condyle (p < 0.001). Conclusions: It is advisable to consider the mechanical advantages as one decides which plate to choose for open rigid internal fixation in low-neck condylar fractures, or to only be aware of the significant differences in mobility within the fracture line after fixation with different dedicated plates.

Minimally Invasive Screw Fixation of Unstable Pelvic Fractures Using the "Blunt End" Kirschner Wire Technique Assisted by 3D Printed External Template.

Objective This study aimed to determine the accuracy and safety of the “blunt end” Kirschner wire (KW) technique for the minimally invasive treatment of unstable pelvic fractures with the assistance of a 3D printed external template. Methods Clinical data of 28 patients with unstable pelvic fractures between January 2016 and January 2018 were retrospectively analyzed. There were 6 cases of B1, 10 of B2, 8 of C1, and 4 of C2 fractures, all of which received surgical treatment. The “blunt end” KW technique with a 3D template was adopted for the minimally invasive placement of the iliosacral (IS) or superior ramus screws. The number of intraoperative fluoroscopies, surgical time, and complications were recorded. Postoperative reduction was assessed using the Matta criteria, and the Majeed score system was used to evaluate postoperative functional recovery. Results The average number of fluoroscopies was 35 per patient, and the average surgical time was 85.2 min. A total of 19 S1 and 28 S2 IS screws were inserted. Eleven antegrade superior ramus screws and 4 retrograde screws were placed in 11 patients, and anterior subcutaneous internal fixation (INFIX) was used to fix the anterior pelvic ring in 17 patients. All patients were followed up for an average of 18 months. Postoperative reduction was evaluated by Matta's criteria: excellent in 16 cases, good in 9 cases, and fair in 3 cases. The Majeed score was used in the last follow-up to evaluate functional recovery: excellent in 13 cases, good in 10 cases, fair in 4 cases, and poor in 1 case. There were no cases of operative vascular injury. Conclusion The “blunt end” KW technique with a 3D printed external template is a safe and effective method for the placement of IS and superior ramus screws in unstable pelvic fractures with minimized surgical duration and radiation exposure.

Fixation of Anterior Pelvic Ring Injuries.

Treatment of anterior pelvic ring injuries involves both acute stabilization during the initial resuscitation and definitive fixation. Definitive management has evolved substantially over the past 40 years with improved patient mobilization and long-term outcomes. Although its use has recently declined, external fixation remains a favorable option in certain situations. Symphyseal plating is the preferred technique for stabilization of symphyseal diastasis because of superior stability and low morbidity. Ramus screws can be effective for simple ramus fractures but require a careful technique because of the proximity of neurovascular structures. The subcutaneous internal fixator provides a good option for obese patients in whom external fixation would be poorly tolerated. Regardless of fixation strategy, posterior ring reduction and stabilization is crucial.

Modified less invasive anterior subcutaneous fixator for unstable Tile-C-pelvic ring fractures: a biomechanical study

BackgroundOperative procedures for unstable pelvic ring fractures remain controversially discussed. Minimally invasive treatment options for pelvic ring fractures have several benefits for the patient. But they can also provide disadvantages. Anterior subcutaneous pelvic fixation (INFIX) has shown promising biomechanical results in pelvic ring fractures, but there is a high complication rate of nerve injuries. An additional screw to the INFIX seems to be more stable. The aim of this study is to compare biomechanical stability of a new modified unilateral INFIX fixing the unilateral injured pelvic ring with the standard INFIX.Methods24 composite synthetic full pelvises were used in this study. 4 groups each with a number of six pelvic specimens were randomly assigned. A C1.3-type pelvic fracture was made with an osteotomy of the sacrum and an osteotomy of the anterior pelvic ring. Fracture fixation was performed within the four groups: (1) unilateral INFIX, (2) “extended” unilateral INFIX + additional pubic ramus pedicle screw, (3) bilateral INFIX, (4) “extended” bilateral INFIX + additional pubic ramus pedicle screw. All specimens were cyclic loaded with 200 N until maximum of 300 N. Distance/dislocation of the fracture fragments were detected with 3D-ultrasound measuring system. Stiffness was calculated.ResultsExtended unilateral INFIX showed the lowest mean dislocation. Lowest rotational stability was displayed by the standard bilateral INFIX. A significant difference (P = 0.04) was shown between the extended unilateral INFIX and the “standard” bilateral INFIX in terms of rotational stability. Extended unilateral INFIX showed significantly improved stability of anterior fracture dislocation (P = 0.01) and unilateral INFIX showed the highest rotational stiffness. Anterior fixation stiffness of the unilateral INFIX was significantly improved using an additional symphysis/pubic ramus screw (P = 0.002).ConclusionExtended unilateral INFIX (+ additional pubic ramus pedicle screw) is a feasible minimally invasive treatment for anterior pelvic ring fractures. Higher stability and lower probability of bilateral nerve damage is provided by the extended unilateral INFIX compared to the standard bilateral INFIX.

Indications for Open Reduction Internal Fixation of Anterior Pelvic Ring Disruptions.

In acute trauma, pelvic ring instability can lead to hemorrhage and hemodynamic instability. Pelvic ring instability and displacement that is not stabilized may lead to chronic pain, sitting imbalance, and limb length inequality. Methods and timing of securing anterior pelvic ring injuries operatively is controversial and debatable. Many orthopaedic trauma surgeons would agree that acceptable methods to treat a disrupted anterior pelvic ring fracture include nonoperative care, external fixation, internal spanning fixators, intramedullary superior ramus screws, and open reduction internal fixation. We will review the indications for open reduction internal fixation fractures and disruptions of the anterior pelvic ring.

Treatment of unstable pelvic fractures by cannulated screw internal fixation with the assistance of three-dimensional printing insertion template

To evaluate the effectiveness of unstable pelvic fractures treated by cannulated screw internal fixation with the assistance of three-dimensional (3D) printing insertion template. The clinical data of 10 patients who underwent surgical treatment for unstable pelvic fractures by cannulated screw internal fixation with the assistance of 3D printing insertion template between May 2015 and June 2016 were retrospectively analysed. There were 7 males and 3 females with an average age of 37.5 years (range, 20-58 years). The causes of injury included falling from height in 5 cases, crushing from heavy load in 1 case, and traffic accidents in 4 cases. The interval from injury to admission was 1-5 hours (mean, 3.1 hours). The fracture situation included 6 cases of sacral fracture, 1 case of right sacroiliac joint dislocation, and 3 cases of iliac bone fracture. There were 10 cases of superior and inferior pubic rami fracture, including 3 cases on the left side (2 cases of suprapubic fracture adjacent to symphysis pubis), 2 cases on the right side, and 5 cases on the bilateral. All fractures were classified according to the Tile system, there were 4 cases of type B2, 1 of type B3, 4 of type C1, and 1 of type C2. The radiological outcome was evaluated by Matta scale, and the positions of the iliosacral screw and superior pubic ramus screw were evaluated according to 3D reconstruction of CT postoperatively. The functional outcome was evaluated by Majeed function scale. The average time of each screw implantation was 30 minutes, and the average blood loss per screw incision was 50 mL. The time of implantation of each sacroiliac screw was 24-96 seconds (mean, 62 seconds), and the time of implantation of each suprapubic screw was 42-80 seconds (mean, 63.2 seconds). The hospitalization duration was 17-90 days (mean, 43.7 days). All incisions healed by first intention. All patients were followed up 12-22 months (mean, 15.6 months). The radiological outcome was excellent in 8 cases and good in 2 cases according to Matta scale; and 3D reconstruction of CT demonstrated that all the 9 iliosacral screws were placed as type Ⅰ, and all the 13 suprapubic ramus screws were placed as grade 0 on the first postoperative day. No complication such as neurovascular injury, screw back out or rupture, or secondary fracture displacement was observed during the follow-up. At 6 months after operation, the X-ray films showed good fracture healing in all the 10 patients. The functional outcome was excellent in 9 cases and good in 1 case according to Majeed scale at 1 year after operation. One patient sustained Tile C2 pelvic disruption complicated with L 5 nerve root injury achieved complete nervous functional recovery at last follow-up. It has advantages of precise screw insertion and lower risk of neurovascular injury to treat unstable pelvic fractures by cannulated screw internal fixation with the assistance of 3D printing insertion template, which can be a good alternative for the treatment of unstable pelvic fractures.

Treatment of Day type Ⅱ pelvic crescent fracture by using percutaneous cannulated screw fixation technique

To evaluate the feasibility and effectiveness of percutaneous cannulated screw fixation for the treatment of Day type Ⅱ pelvic crescent fracture. The clinical data of 14 patients with Day type Ⅱ pelvic crescent fractures underwent closed reduction and percutaneous cannulated screw fixation between January 2009 and July 2016 were retrospectively analysed. There were 9 males and 5 females, aged 17-65 years (mean, 38 years). The causes of injury included traffic accident in 8 cases, falling from height in 3 cases, bruise injury in 3 cases; all were closed fractures. According to Tile classification, there were 8 cases of type B, 6 cases of type C. There were 13 cases combined with fracture of the anterior pelvic ring, including 8 cases of superior and inferior ramus of pubis fracture, 1 case of superior ramus of pubis fracture with symphysis separation, and 4 cases of symphysis separation. The interval of injury and admission was 1- 72 hours (mean, 16 hours), and the interval of injury and operation was 3-8 days (mean, 5 days). After operation, the reduction of fracture was evaluated by the Matta evaluation criteria, the clinical function was assessed by Majeed function assessment. The operation time was 35-95 minutes (mean, 55 minutes), cumulative C-arm fluoroscopy time was 3-8 minutes (mean, 5 minutes), no iatrogenic vascular injury and pelvic organ damage occurred. Postoperative X-ray films at 2 days indicated that 2 cases of vertical shift and 2 cases of mild rotation were not completely corrected. Postoperative CT examination at 3 days indicated that 2 pubic joint screws broke through the obturator bone cortex. None of the pubic ramus screws entered into the acetabulum, but a screw of superior pubic branch broke through the posterior cortical of superior pubic branch, a screw of posterior ilium column broke through the medial bone cortex of the ilium, and no clinical symptom was observed. One patient suffered from wound infection in the pubic symphysis, then healed after 2 weeks of wound drainage, the other wounds healed by first intention. According to Matta criterion for fracture reduction, the results were excellent in 9 cases, good in 4 cases, and fair in 1 case with an excellent and good rate of 92.9%. All patients were followed up 8-24 months (mean, 14 months). All fractures healed at 4 months and restored to the normal walking at 6 months after operation, 3 patients suffered from slight pain in the sacroiliac joints and slight claudication when they were tired or walked for a long time and unnecessary for special treatment. One patient felt pain in the back of the iliac spine when he was lying down. During the follow-up, no screw loosening or other internal fixation failure occurred. At last follow-up, according to Majeed functional evaluation criteria, the results were excellent in 7 cases, good in 5 cases, and fair in 2 cases with an excellent and good rate of 85.7%. The percutaneous cannulated screw fixation is a safe treatment for Day type Ⅱ pelvic crescent fracture, which has a reliable fixation and good effectiveness.