Anterior Sacroiliac Research Articles

Severe multiple injuries in a 15-year-old boy with pelvic fracture complete anterior dislocation of the sacroiliac joint and rupture of the internal and external iliac arteries: A case report of a rare injury.

Anterior dislocation of the sacroiliac joint combined with pelvic fractures is relatively rare in clinical practice. It is often associated with hemodynamic instability and severe injuries to other regions, resulting in a complex condition, prolonged treatment duration, and high rates of mortality and disability. However, there are few reports in the literature describing the diagnosis and treatment of anterior dislocation of the sacroiliac joint. In this case, the patient sustained a pelvic fracture with anterior sacroiliac joint dislocation and rupture of both the internal and external iliac arteries following a motor vehicle accident, making it an even rarer and more challenging case to treat. Reporting such cases can enhance the understanding of the diagnosis and treatment of anterior sacroiliac joint dislocation with rupture of the iliac arteries and provide valuable references for similar cases. The patient was riding an electric bicycle and was hit by a small truck, resulting in a pelvic fracture, anterior dislocation of the sacroiliac joint, and rupture of the internal and external iliac arteries. The patient was diagnosed with open pelvic fracture (type C1.2), left complete anterior dislocation of the sacroiliac joint, left acetabular fracture, left internal and external iliac arteriovenous rupture. emergency room resuscitation, intensive care unit resuscitation, 6 surgeries and perioperative management. He has been discharged from the hospital for more than 1 year and was rechecked every month after discharge, the fracture has healed, there is no obvious pain and discomfort in and around the wound, he has been fitted with a prosthesis, and he is doing the walking function exercise. Pelvic fracture with anterior sacroiliac dislocation is clinically rare and critical, and is associated with large vessel rupture, severe organ damage, and high mortality and disability rates. Rapid restoration of pelvic stability and hemodynamic stability is the key to treatment. Rapid transfer to a tertiary trauma center, rapid examination through the green channel to clarify the diagnosis, close intensive care, and reasonable multidisciplinary teamwork for surgical intervention are all valuable experiences that we have concluded.

Anterior Sacroiliac Fracture Dislocation: A Comparative Radiologic analysis of Crescent Fractures in Pelvic Ring Injuries: A Retrospective Study.

Background and Objectives: Anterior sacroiliac fracture dislocation (ASFD), also known as locked pelvis, is a rarely reported diagnosis. The types of ASFDs are often misdiagnosed as lateral compression fractures due to the presence of crescent fractures. In this study, we distinguished ASFD from lateral compression fractures (LC 2) and studied their characteristics. Materials and Methods: This is a retrospective study involving patients from a Level 1 trauma center. Fifty-nine patients under the age of 65 years with crescent fractures caused by a high-energy mechanism were investigated. Results: The incidence of ASFD was 25% (15 of 59) in patients with crescent fractures. Among the 15 patients, 6 had override of the ilium over the sacrum, inhibiting reduction in the sacroiliac joint. Pre-operative radiographic evaluations revealed that vertical displacement of the ASFD was larger than that of lateral compression fracture (LC 2) in the outlet view (mean 9.5 vs. 1.9 mm, p = 0.013), and the pelvic asymmetry ratio was larger in ASFD (mean 7.8 vs. 4.1, p = 0.006) in the pelvis AP view. All patients achieved union after surgery. Post-operative radiography showed no significant vertical displacement difference. There was no difference in vascular injury or hemodynamic instability requiring embolization or preperitoneal pelvic packing (PPP) between the two groups. Conclusions: Patients with ASFD have greater vertical displacement and asymmetry compared to patients with LC 2 fractures. These fractures must be distinguished for appropriate reduction and anterior plate fixation.

Do we need another screw? Sacroiliac screw fixation in open-book pelvic ring injuries (APC type II).

To compare anterior plate fixation (SP fixation) both alone and in combination with an additional posterior sacroiliac screw (SP+SIS fixation) as a treatment for pelvic ring injuries with widening of the pubic symphysis and disruption to the anterior sacroiliac ligaments. To find studies with pelvic ring injuries (APC II; B2.3d) and SP or SP+SIS fixation, a systematic literature review was conducted by searching four databases. A protocol was published a priori at Open Science Framework (https://doi.org/10.17605/OSF.IO/3YHAV). Exclusion criteria included perineal injuries, chronic instability of the symphysis, complete sacroiliac separation, and pediatric patients (age <18 years). Primary outcomes of interest were defined as implant failure, health-related quality of life, and revision rate. Altogether, 1861 studies were screened, and 40 studies qualified for full-text analysis. In total, 14 studies (two surveys, six biomechanical studies, and six retrospective clinical studies) were included. The surveys revealed that surgeons who had more recently begun practicing were more likely to use posterior fixation (SP+ISS). The biomechanical studies were heterogenous and did not yield a uniform pattern. In clinical studies, 117 patients (45%) received SP fixation, and 142 patients (55%) received SP+SIS fixation. Complications occurred in 31 SP patients (30%) and in five SP+SIS patients (3.5%). A high risk of bias was uncovered, and reporting was found to be incomplete. SP+SIS may have the potential to improve outcomes, but the evidence remains too inconclusive to draw reliable recommendations.

Clustered Occurrence of Osteitis Condensans Ilii in Patients with Symptomatic Hip Dysplasia.

Osteitis condensans ilii (OCI) is a relatively rare benign disease of the lower anterior sacroiliac joint (SIJ) region that can cause symptoms such as low back pain (LBP), lateral hip pain and nonspecific hip or thigh pain. Its exact pathoetiology remains to be clarified. The aim of this study is to determine the prevalence of OCI in patients with symptomatic developmental dysplasia of the hip (DDH) undergoing periacetabular osteotomy (PAO) to identify potential clustering of OCI in a with altered biomechanics of hip and SIJs. A retrospective investigation of all patients who underwent periacetabular osteotomy in a tertiary reference hospital from January 2015 to December 2020. Clinical and demographic data were retrieved from the hospital's internal medical records. Radiographs and magnetic resonance images (MRIs) were reviewed for the presence of OCI. A t-test for independent variables was conducted to identify differences between patients with and without OCI. A binary logistic regression model was established to determine the influence of age, sex and body mass index (BMI) on the presence of OCI. The final analysis included 306 patients (81% female). In 21.2% of the patients (f: 22.6%; m: 15.5%), OCI was present. BMI was significantly higher in patients with OCI (23.7 kg/m2 vs. 25.0 kg/m2; p = 0.044). Binary logistic regression revealed that a higher BMI increased the likelihood of sclerosis in typical osteitis condensans locations, OR = 1.104 (95%-CI [1.024, 1.191]), as did female sex, OR = 2.832 (95%-CI [1.091, 7.352]. Our study revealed a considerably higher prevalence of OCI in patients with DDH than in the general population. Furthermore, BMI was shown to have an influence on the occurrence of OCI. These results support the theory that OCI is attributable to altered mechanical loading of the SIJs. Clinicians should be aware that OCI is common in patients with DDH and a potential cause of LBP, lateral hip pain and nonspecific hip or thigh pain.

A cadaveric biomechanical evaluation of anterior posterior compression II injuries

Pelvic fractures are associated with high morbidity and often require surgical intervention. An Anterior Posterior Compression (APC) II injury consists of disruption at the pubic symphysis and anterior sacroiliac joint. Studies investigating specific ligamentous contributions would aid in development of novel fixation techniques. The objective of this study is to determine the level of pelvic destabilization from progressive soft tissue disruptions associated with APC II injuries. Six fresh-frozen cadaveric pelvises were dissected of soft tissues, preserving joint capsules and ligaments. Each pelvis was secured in a double-leg stance and joint motion was tracked with the specimens cyclically loaded to 60% body weight. Each specimen was measured in the intact state and again following stepwise destabilization to an APC II injury model (PS: sectioned pubic symphysis, IPS JOINT: PS+ipsilateral anterior sacroiliac, sacrotuberous, sacrospinous ligaments sectioned, IPS LIGS: IPS JOINT+ipsilateral interosseous ligaments sectioned, IPS JOINT+CONT ASI: IPS LIGS+contralateral anterior sacroiliac ligament disruption). Compared to the intact state, there was a statistically significant increase in movement in the IPS JOINT (ipsilateral 177%, p<0.001; contralateral 46%, p<0.005) and IPS JOINT+CONT ASI (ipsilateral 184%, p<0.002; and contralateral 62%, p<0.002) states bilaterally. No significant change was demonstrated in the PS or IPS LIGS state. Disruption of ipsilateral ligamentous structures destabilized both sacroiliac joints. The interosseous and posterior sacroiliac ligaments provide the majority of stability of the sacroiliac joint and will likely benefit most from surgical stabilization. mechanism-based reasoning.

Effects of manipulations of oblique pulling on the biomechanics of the sacroiliac joint: a cadaveric study

BackgroundThere are many reports on the treatment of sacroiliac joint dysfunction by manipulation of oblique pulling (MOP). However, the specific mechanism of MOP on the sacroiliac joint remains unclear. This study aimed to investigate the effect of MOP on the biomechanics of the sacroiliac joint and the effect of the anterior sacroiliac ligament on the stability of the sacroiliac joint.MethodsFirst, MOP-F1 (F: force) and MOP-F2 were applied to nine cadaveric pelvises. Then, segmental resection of the anterior sacroiliac ligament was performed. The range of motion of the sacroiliac joint was observed in all procedures.ResultsUnder MOP-F1 and F2, the average total angles were 0.84° ± 0.59° and 1.52° ± 0.83°, and the displacements were 0.61 ± 0.21 mm and 0.98 ± 0.39 mm, respectively. Compared with MOP-F1, MOP-F2 caused greater rotation angles and displacements of the sacroiliac joint (p = 0.00 and p = 0.01, respectively). In addition, the rotation angles and displacements of the sacroiliac joint significantly increased after complete resection of the anterior sacroiliac ligament (p = 0.01 and p = 0.02, respectively). The increase was mainly due to the transection of the upper part of the anterior sacroiliac ligament.ConclusionsMOP-F2 caused greater rotation angles and displacements of the sacroiliac joint and was a more effective manipulation. The anterior sacroiliac ligament played an important role in maintaining the stability of the sacroiliac joint; the upper part of the anterior sacroiliac ligament contributed more to the stability of the joint than the lower part.

The placement of percutaneous retrograde acetabular posterior column screw based on imaging anatomical study of acetabular posterior column corridor

ObjectiveTo explore the entry point, orientation, and fixation range of retrograde acetabular posterior column screw.MethodThe computed tomography data of 100 normal adult pelvises (50 males and 50 females, respectively) were collected and pelvis three-dimensional (3D) reconstruction was performed by using Mimics software and the 3D model was imported into Geomagic Studio software. The perspective of acetabular posterior column was carried out orienting from ischial tuberosity to iliac fossa in the Mimics software. Virtual screw was inserted perpendicular to the transverse section of acetabular posterior column corridor, and the maximum screw diameter, entry point, orientation, exit point were measured. The screw fixation range, the easy-to-penetrate sites, and intraoperative optimal fluoroscopic views were assessed.ResultsThe acetabular posterior column corridor showed a triangular-prism shape. The virtual screw entry point was located at the midline between the medial and lateral edges of the ischial tuberosity. The distance between the entry point and the distal ischial tuberosity was around 13 mm. The distances between the exit point and the true pelvis rim, and ipsilateral anterior sacroiliac joint line were (19.33 ± 2.60) mm and (23.65 ± 2.42) mm in males, respectively. As for females, those two data were (17.63 ± 2.00) mm and (24.94 ± 2.39) mm, respectively. The maximum diameters of screws were (17.21 ± 1.41) mm in males and (15.54 ± 1.51) mm in females. The angle between the retrograde posterior column screw and the sagittal plane was lateral inclination (10.52 ± 3.04)° in males, and that was lateral inclination (7.72 ± 2.99)° in females. Correspondingly, the angle between the screw and the coronal plane was anterior inclination (15.00 ± 4.92)° in males, and that was anterior inclination (12.94 ± 4.72)° in females. Retrograde acetabular posterior column screw through ischial tuberosity can fix the acetabular posterior column fractures which were not 4 cm above the femoral head center. The easy-to-penetrate sites were located at the transition between the posterior acetabular wall and the ischium, the middle of the acetabulum, and 1 cm below the greater sciatic notch, respectively. The iliac oblique 10°, iliac oblique 60°, and obturator oblique 60° views were the intraoperative optimal fluoroscopic views to assess whether the screw was safely inserted.ConclusionRetrograde acetabular posterior column screw entry point is located at the midline between the medial and lateral edges of the ischial tuberosity, which is 1.3 cm far from the distal ischial tuberosity. The screw direction is about 10° lateral inclination and 15° anterior inclination, which can fix the acetabular posterior column fractures which were not 4 cm above the femoral head center.

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.

Anatomic basics and technical approaches: sacral preauricular extensions, preauricular sulci and dorsal pubic pits in modern anatomical specimens.

The aim of this study is the evaluation of three selected osseous pelvic features in modern anatomical specimen - the sacral preauricular extension, the preauricular sulcus and pits on the dorsal side of the pubic bone laterally to the symphysis. The specificity and significance of these features are under debate and their genesis is largely unclear. Descriptive data of specific soft tissue structures surrounding the anterior sacroiliac joint gap and the pubic symphysis were generated by assessing 20 fresh pelves and 12 embalmed hemipelves from human body donors. Computed tomography (CT) was performed on all specimens and three-dimensional (3D) surface models were generated and analysed. Afterwards, all the specimens underwent anatomical dissection and finally maceration. During dissection, it became apparent that the anterior sacroiliac ligament, due to its position, shape and potential impact on the sacroiliac joint and adjacent osseous structures, requires a detailed analysis of its dimension. The most promising result, in terms of the sacral preauricular extension, was that the measurements of the triangular part of the anterior sacroiliac ligament were significantly longer in females than in males. Pelvic floor muscle fibres and fascial parts were directly connected to this ligament in some specimens, which is an important starting point for a larger in-depth study. The evaluation of the anatomic structures in connection to dorsal pitting refutes the assumption that the pelvic floor muscles or fasciae could exert influence on its formation. A histological evaluation of the ligaments of the pubic symphysis, especially the dorsal pubic ligament, would be expedient to clarify the etiology of this feature.

A novel technique for stabilising sacroiliac joint dislocation using spinal instrumentation: technical notes and clinical outcomes

PurposeCurrently, sacroiliac joint dislocations, including crescent fracture–dislocations, are treated using several techniques that have certain issues. We present the technical details and clinical outcomes of a new technique, anterior sacroiliac stabilisation (ASIS), performed using spinal instrumentation.MethodsASIS is performed with the patient in a supine position via the ilioinguinal approach. The displacements are reduced and fixed by inserting cancellous screws from the sacral ala and iliac brim; the screw heads are bridged using a rod and locked. We performed a retrospective review of patients with iliosacral disruption who underwent ASIS between May 2012 and December 2020 at two medical facilities. The patients were assessed for age, sex, injury type, associated injuries, complications, functional outcome by evaluating the Majeed pelvic score after excluding the sexual intercourse score and fracture union.ResultsWe enrolled 11 patients (median age: 63 years). The median operative time was 195 min, median blood loss was 570 g, and eight patients (72.3%) required blood transfusion. The sacral and iliac screws had a diameter of 6.0–8.0 mm and 6.2–8.0 mm, and a length of 50–70 mm and 40–80 mm, respectively. Bone union was achieved with no marked loss of reduction in the median follow-up period of 12 months in all cases. The median Majeed score at the final follow-up was 85/96.ConclusionASIS is a rigid internal fixation method that provides angular stability. Despite invasiveness issues compared to iliosacral screw fixation, this method is easy to confirm and achieves precise reduction.

A biomechanical in-vitro study on an alternative fixation technique of the pubic symphysis for open book injuries of the pelvis

PurposeImplant failure rates remain high after plate fixation in pelvic ring injuries. The aim of this study was to compare an alternative fixation technique with suture-button devices and anterior plate fixation in partially stable open-book injuries. Material and MethodsWe acquired 16 human fresh frozen anatomic pelvic specimens. The sacrospinous, sacrotuberous, and anterior sacroiliac ligaments were bilaterally released, and the pubic symphysis transected to simulate a partially stable open-book (AO/OTA 61-B3.1) injury. The specimens were randomly assigned to the two fixation groups. In the first group two suture-button devices were placed in a criss-crossed position through the symphysis. In second group a six-hole plate with standard 3.5 unlocked bicortical screws was used for fixation. Biomechanical testing was performed on a servo-hydraulic apparatus simulating bilateral stance, as described by Hearn and Varga. Cyclic compression loading with a progressively increasing peak load (0.5 N/cycle) was applied until failure. The failure mode, the load and the number of cycles at failure and the proximal and distal distance of the symphysis during testing were compared. ResultsThere was no implant failure in either of the two groups. Failures occurred in nine pelvises (56.2%) at the fixation between the sacrum and the mounting jig and in seven pelvises (43.8%) in the sacroiliac joint. Neither the ultimate load nor the number of cycles at failure differed between the surgical techniques (p = 0.772; p = 0.788, respectively). In the suture button group the mean ultimate load was 874.5 N and the number of cycles at failure was 1907.9. In the plate group values were 826.1 N and 1805.6 cycles, respectively. No significant differences at proximal and distal diastasis of the symphysis were monitored during the whole loading process. ConclusionThe fixation with suture button implants showed comparable results to anterior plate fixation in open-book injuries of the pelvis.

Comparative Finite Element Analysis of Fixation Techniques for APC II Open-Book Injuries of the Pelvis

Open-book fractures are defined as the separation of the pubic symphysis or fractures of the rami and disruption of the anterior sacroiliac, sacrotuberous, and sacrospinal ligaments. They can be stabilized by fixation of the anterior arch. However, indications and advantages of additional placement of iliosacral screws remain unknown. A CT-based model of the healthy pelvis was created and ligaments were modeled as tension springs. Range of motion of the sacroiliac joint and the pubic symphysis, and bone and implant stresses were compared for the physiological model, anterior symphyseal plating alone, and additional posterior fixation using two iliosacral screws. The range of motion of the sacroiliac joint was reduced for anterior symphyseal plating alone and further decrease was noted with additional posterior fixation. Von Mises stresses acting on the symphyseal plate were 819.7 MPa for anterior fixation only and 711.56 MPa for additional posterior fixation equivalent with a safety factor of 1.1 and 1.26, respectively. Implant stresses were highest parasymphyseal. While bone stresses exhibited a more homogeneous distribution in the model of the healthy pelvis and the model with anterior and posterior fixation, pure symphyseal plating resulted in bending at the pelvic rami. The analysis does not indicate the superiority of either anterior plating alone or additional posterior fixation. In both cases, the physiological range of motion of the sacroiliac joint is permanently limited, which should be taken into account with regard to implant removal or more flexible techniques for stabilization of the sacroiliac joint.

Quantitative evaluation of the sacroiliac joint fixation in stress reduction on both sacroiliac joint cartilage and ligaments: A finite element analysis

BackgroundThe sacroiliac joint fixation is the last resort for patients with prolonged and severe joint pain. Although the clinical results of anterior fixations are conclusive, there exist several inevitable drawbacks with the surgical method such as the difficulty performing the surgery due to the presence of many organs. The posterior fixation technique has thus been developed to overcome those inconveniences. This study aims to assess in silico the mechanical environment following posterior and anterior fixations, focusing on stresses in both the sacroiliac cartilage and dorsal ligamentous part, as well as loads experienced by the pelvic ligaments. MethodsSacroiliac joint cartilage, dorsal ligamentous part stresses and pelvic ligaments loads were evaluated with three types of fixation models. A vertical load of 600 N was applied, equally distributed via both acetabula when standing and sitting. FindingsResults show that the anterior sacroiliac joint fixation reduced von Mises stresses in the cartilage and dorsal ligamentous part and decreased ligaments loads more extensively than the posterior fixation when compared to the untreated model as a reference. However, the posterior fixation still remains the desirable and preferential treatment. InterpretationThe anterior sacroiliac joint fixation showed better performances compared to the posterior one; however, the lower invasive aspect of the latter is a fundamental clinical advantage which also has the possibility to be improved by considering various screws and cages configurations. This study provides a beneficial suggestion to improve the current fixation technique.

Choosing between the Conventional Plates, Locking Plates, or Iliosacral Screws for Sacroiliac Joint Dislocation: A Biomechanical Comparison Study

Background: This study examines the comparison of biomechanical strengths of three kinds of the most familiar implants available in Indonesia: conventional and locking sacroiliac plates and screws, also iliosacral screws. Despite the common thought that iliosacral screws are preferred compared to conventional plates and screws due to its biomechanic superiority, this study tested whether the locking plates and screws could offer an alternative.Materials and Methods: This study was an in vitro experimental study with a Randomized Post Test - Only Control Group Design using pelvic bones from male cadavers aged 20-50 y.o. Twelve samples were divided into three treatment groups and one control group. Group P1 was fixed with two conventional plates, P2 was fixed with two locking plates, P3 was fixed with two iliosacral screws, and control group K with sacroiliac joint was intact. Each group was given an increasing load until a vertical shift of the sacroiliac joint ≥ 2.0 mm was obtained.Results: The average force load for 2 mm displacement among the fixation systems being tested shows a statistically significant difference (p0.05). Load failure force for 2 mm displacement in the locking plate and screw group has the highest average (591.33 ± 56.08 N) compared to the iliosacral screw group (583.67 ± 73.56 N) and conventional plate and screw group (574 ± 106.05 N).Conclusions: Biomechanically, the fixation system using two locking anterior sacroiliac plates and screws is more stable than the iliosacral screws and conventional sacroiliac plates and screws.

A biomechanics study on ligamentous injury in anterior-posterior compression type II pelvic injury

BackgroundAnterior-posterior compression (APC) type II pelvis fracture is caused by the destruction of pelvic ligaments. This study aims to explore ligaments injury in APC type II pelvic injury.MethodFourteen human cadaveric pelvis samples with sacrospinous ligament (SPL), sacrotuberous ligament (SBL), anterior sacroiliac ligament (ASL), and partial bone retaining unilaterally were acquired for this study. They were randomly divided into hemipelvis restricted and unrestricted groups. We recorded the separation distance of the pubic symphysis and anterior sacroiliac joint, external rotation angle, and force when ASL ruptured. We observed the external rotation damage to the pelvic bone and ligaments.ResultWhen ASL failed, there was no significant difference in pubic symphysis separation (28.6 ± 8.4 mm to 23.6 ± 8.2 mm, P = 0.11) and anterior sacroiliac joint separation (11.4 ± 3.8 mm to 9.7 ± 3.9 mm, P = 0.30) between restricted and unrestricted groups. The external rotation angle (33.9 ± 5.5° to 48.9 ± 5.2°, P < 0.01) and force (553.9 ± 82.6 N to 756.6 ± 41.4 N, P < 0.01) were significantly different. Pubic symphysis separation between two groups ranged from 14 to 40 mm. In the restricted group, both SBL and SPL were injured. SPL ruptured first, and then SBL and the interosseous sacroiliac ligament were damaged while the posterior ligament remained unharmed. In the unrestricted group, interosseous sacroiliac ligament and posterior sacroiliac ligaments were damaged, while SBL and SPL were not. When the ASL, SBL, and SPL all failed, pubic symphysis and anterior sacroiliac joint separation between two groups increased significantly (from 28.6 ± 8.4 to 42.0 ± 7.6 mm, 11.4 ± 3.8 to 16.7 ± 4.2 mm respectively, all P < 0.05).ConclusionPelvic external rotation injury is either hemipelvic restricted or unrestricted, which can result in different outcomes. When the ASL ruptures, the unrestricted group needs greater external rotation angle and force, without SBL or SPL injury, while both SBL and SPL were injured in another group. When ASL fails in two groups, pubic symphysis separation fluctuates considerably. Finally, when the ASL ruptures, SBL and SPL may be undamaged.

To Study the Effect of Mulligan Mobilization Versus Conventional Therapy in Sacroiliac Joint Pain

Background: Sacroiliac Joint Pain (SIJP) is a pain arising from SIJ structures such as anterior sacroiliac ligament, posterior sacroiliac ligament, interosseous ligaments or articular cartilage. The treatment of sacroiliac joint pain is quite challenging. The standard physical therapy (PT) interventions include repetitive exercises, manual joint mobilization, manipulation, bracing, massage, patient education, aerobic conditioning, general therapeutic exercise and electrotherapeutic modalities. Objectives: To compare the effect of mulligan mobilization versus conventional therapy on pain on VAS, Lumbar Range of motion and functional disability in patients with sacroiliac joint pain. Material and Method: A total 93 patients were screened as per the inclusion and exclusion criteria. Patients were randomly allocated in two groups. Group A received mulligan mobilization and Ultrasound therapy and group B received Conventional therapy i.e Ultrasound therapy. Outcome measures assessed were VAS for pain, Lumbar flexion by modified schober’s test and MODQ for functional Disability. Result: Mean difference of Pain on VAS 4.41±1.04 in group A and in group B 3.63±1.27. Mean difference in Lumbar flexion ROM in group A it was 1.30 ± 0.67 and in group B it was 0.98 ±0.55 Mean difference in MODI Score in group A was 34.67 ± 10.84 and in group B it was 13.50 ± 6.45. Conclusion: In the present study, we found that both the techniques Mulligan mobilization and Conventional therapy are effective in the subjects with Sacroiliac joint pain but Mulligan mobilization was found to be more effective than conventional therapy.

MRI Evaluation of the Posterior Pelvic Bony and Soft Tissue Injuries With Tile C Displaced Pelvic Fractures in Young Children.

Disruption through the weak iliac apophysis growth plate is characteristic in unstable pediatric posterior pelvic injuries. Magnetic resonance imaging (MRI) scans would help in the assessment of bony injuries in addition to the trunk and abdominal wall muscles and the posterior sacroiliac and pelvic floor ligaments. All children with displaced pelvic fractures Tile C and open triradiate cartilage between September 2010 and December 2017 who had computed tomography evidence of iliac apophysis avulsion and available MRI scans were reviewed. The paravertebral, anterior abdominal wall and iliacus muscles, and the sacroiliac and pelvic floor ligaments were evaluated. Eight patients had pelvic MRI scans in addition to the standard computed tomography. All were males and the average age was 7.5 years (4 to 14 y). The iliac apophysis was attached posteriorly to the quadratus lumborum and erector spinae muscles and to the posterior sacroiliac complex. The bony iliac wing lost its connection to the axial skeleton and its muscular attachment to the erector spinae and quadratus lumborum. The iliacus muscle was elevated of the iliac fossa in all cases. The anterior sacroiliac ligaments were disrupted in all while the pelvic floor ligaments were disrupted in 5 patients, intact in 2 and could not be clearly visualized in 1 patient. In 2 patients, anterior abdominal wall muscles were split in 2 layers, the external oblique attached to the displaced bony ilium and the internal oblique and transversus abdominis attached to the iliac crest apophysis. This deep layer was continuous distally with the iliacus muscle. This could be explained by the anatomic arrangement of the thoracolumbar fascia and its middle layer. The posterior pelvic ring would be disrupted through the weak chondro-osseous connection between the bony ilium and its well-fixed iliac crest apophysis which is attached to the posterior sacroiliac complex, paravertebral muscles, and the posterior and middle layers of the thoracolumbar fascia. This is central to our understanding for the pathomechanics of those injuries and for operative fixation.

FIXATION OF ACETABULAR (ANTERIOR RIM, QUADRILATERAL PLATE) FRACTURES WITH MODIFIED STOPAA APPROACH “OPTIMUM APPROACH”

Introduction: Pelvis is important bony structure of body that provide main weight bearing surface for the hip joint in form of acetabulum, with the advancement of the high speed transportations, pelvic trauma has been raised in numbers so as acetabular fractures. Stable acetabular fractures fixation with accurate anatomic reduction always has been a big challenge for orthopaedic surgeons. Acetabular fractures fixation has risen step ahead after evolution of modified stoppa approach, as this approach allow minimum soft tissue handling, easy accessibility and provide adequate exposure to intrapelvic structures. Recently modified stoppa approach has evolved as primary approach for acetabular fractures fixation. AIM: To perform acetabulum fracture fixation through an optimum surgical exposure “modified stoppa approach” Materials And Method: this study conducted on 20 patients who presented with acetabular fractures after an RTA or fall from height or due to other various cause. Fracture fixation done through modified stoppa approach for those who met in our inclusion criteria ,to provide pelvic and hip joint stability. Patients demographics, location, duration from injury to surgical interventions, duration of hospital stay, if any complication occurred during surgery were recorded. Result: Out of total 20 patients 17 were male and 3 patients were female, average age 39year[Range from 18 to 60 yr], 12 patients having isolated unilateral acetabulum fracture present, 2 having bilateral acetabular fracture and 4 having associated pelvic bone fracture along with unilateral acetabulum fracture, 2 patients having long bone of lower limb fracture along with acetabular injury. All the fixation done through modified stoppa approach. Intraoperatively in all the patients easy accessibility and wide exposure obtain for intrapelvic structures. All the neurovascular structures easily identified and protected over the surgical site. Intraoperatively no clinical and radiological complication were observed in all patients. Post operatively all the patients were able to bear weight, within the 12±4 week,. Conclusion: We got a conclusion that the modified stoppa approach is anterior intrapelvic approach which provides an excellent view to the acetabular[anterior column, quadrilateral plate, posterior hemitransverse] and other intrapelvic structures, with minimal soft tissue handling, easy accessibility to preserve neurovascular structures. This approach provides direct access to the pubis, the posterior surface of the ramus, the quadrilateral surface, the pubic eminence, and the infrapectineal surface, as well as the sciatic buttress, sciatic notch, and the anterior sacroiliac joint. It can be used in most of the acetabular fractures fixation, the only downside is being the steep learning curve and familiarity of the structures while addressing these fractures. Keywords: Acetabulum, Acetabular fracture, Modified stoppa approach, quadrilateral plate.

Differentiation of anteroposterior pelvic compression type I and II injuries and severity evaluation

Objective To investigate the reliability of using the pubic symphysis diastasis of 25 mm and anterior separation distance of sacroiliac joint to differentiate anteroposterior compression (APC) type I and II injuries as well as assess the injury severity. Methods A total of 11 (seven males and four females) fresh cadaver specimens with 22 hemipelvis were collected. The pelvic APC injury test models including fixed hemipelvis (restricted group) and unfixed hemipelvis (non-restricted group) were established, with 11 hemipelvis in each group according to the random number table method. Meanwhile the specimens were divided into male group (14 hemipelvis) and female group (eight hemipelvis), simulating APC type injury external rotation hemipelvis. The public symophysis interval and anterior interval of sacroiliac joint of the original pelvis, the pubic symphysis diastasis and anterior diastasis of sacroiliac joint after anterior tibiofibular ligament failure, as well as the affected pelvis ligament and sacral ligament injury were recorded and compared between the restricted and non-restricted groups, male and female groups. Results There were no significant differences in the public symphysis interval of the original pelvis and anterior interval of sacroiliac joint between the restricted group and the non-restricted group (P>0.05). The pubic symphysis interval of the original pelvis was [(5.13±0.61)mm] in male group and (4.03±0.84)mm] in female group (P 0.05). In terms of anterior interval of sacroiliac joint, there was significant difference between male and female groups (P 0.05). In the restricted group, sacrotuberous ligament injuries were found in four patients, and sacrospinous ligament injuries in five, whhile there were no obvious sacrospinous ligament and sacrotuberous ligament injuries in non-restricted group. There were 10 specimens with the pubic symphysis diastasis ≥23.36 mm and 10 specimens with the diastasis distance of anterior sacroiliac joint ≥9.82 mm (46%), and there were 15 specimens with at least the pubic symphysis interval ≥23.36 mm or the anterior interval of sacroiliac joint ≥9.82 mm (68%). Conclusions The public symphysis interval ≥ 23.36 mm or anterior interval of sacroiliac joint ≥ 9.82 mm can distinguish anteroposterior compression I from II injuries, and the combination of the two criteria can be beneficial to assessment of pelvic injury severity. Key words: Pelvis; Ligaments; Injury classification

Establishment of a three-dimensional finite element model of pelvic anteroposterior compression for analysis of related ligamentous damages

Objective To establish a three-dimensional finite element model of pelvic anteroposterior compression (APC) for analysis of mechanisms for related ligamentous damages. Methods A finite element model and a laboratory mechanical model of APC were established using the same pelvic specimens. In a finite element model of normal pelvic bones and ligaments, after the right pelvis was fixated the pubic symphysis (PS) was sectioned. Next, a manual external mobile force was gradually applied to the left hemipelvis to make the PS diastasis 10, 20, 30, 40, 60, 80 and 100 mm apart. The mechanical experiment revealed the anterior sacroiliac ligament (ASIL) was ruptured when the PS diastasis reached 28 mm. After the strain value of ASIL was calculated through the finite element model, it was applied to the other pelvic ligaments. The displacement in front of the sacroiliac joint (SIJ), stress, strain and extent of injury and disruption of sacrotuberous/sacrospinous ligaments (STL/SSL) with a corresponding PS diastasis were observed and recorded. Results ASIL failed at the point when the PS diastasis was 28 mm and the displacement in front of SIJ was 7.41±1.14 mm. The strain and maximum principal stress of ASIL calculated in the finite element model were 259.5% and 543.24 MPa respectively. The maximum principal stress value of SSL was 35.00 MPa at the point of failure when the PS diastasis and the displacement in front of SIJ were 51 mm and 15.23±2.88 mm, respectively. When the PS diastasis and the displacement in front of SIJ were 100 mm and 7.5 mm respectively, the maximum principal stress value of STL was 16.17 MPa but the strained ligament was not ruptured. When the pelvis was rotated externally step by step, the ASIL failure was followed by the rupture of SSL but not necessarily by the STL failure. Conclusion As the finite element pelvic bone-ligament model established in this study can effectively simulate the mechanisms for APC injury, it can be used to evaluate different extents of pelvic ligamentous injury, providing a basis for the biomechanical study of pelvic bones and ligaments. Key words: Pelvis; Ligaments; Wound and injuries; Biomechanics; Finite element analysis