Unstable Posterior Pelvic Ring Injuries Research Articles

Correlating preoperative imaging with intraoperative fluoroscopy in iliosacral screw placement

BackgroundPercutaneous iliosacral screw placement can successfully stabilize unstable posterior pelvic ring injuries. Intraoperative fluoroscopic imaging is a vital component needed in safely placing iliosacral screws. Obtaining and appropriately interpreting fluoroscopic views can be challenging in certain clinical scenarios. We report on a series of patients to demonstrate how preoperative computed tomography (CT) imaging can be used to anticipate the appropriate intraoperative inlet and outlet fluoroscopic views.Materials and methods24 patients were retrospectively identified with unstable pelvic ring injuries requiring operative fixation using percutaneous iliosacral screws. Utilizing the sagittal reconstructions of the preoperative CT scans, anticipated inlet and outlet angle measurements were calculated. The operative reports were reviewed to determine the angles used intraoperatively. Postoperative CT scans were reviewed for repeat measurements and to determine the location and safety of each screw.ResultsPreoperative CT scans showed an average inlet of 20.5° (7°–37°) and an average outlet of 42.8° (30°–59°). Intraoperative views showed an average inlet of 24.9° (12°–38°) and an average outlet of 42.4° (29°–52°). Postoperative CT scans showed an average inlet of 19.4° (8°–31°) and an average outlet of 43.2° (31°–56°). The average difference from preoperative to intraoperative was 4.4° (−21° to 5°) for the inlet and 0.45° (−9° to 7°) for the outlet. The average difference between the preoperative and postoperative CT was 2.04° (0°–6°) for the inlet and 2.54° (0°–7°) for the outlet.ConclusionThere is significant anatomic variation of the posterior pelvic ring. The preoperative CT sagittal reconstruction images allow for appropriate preoperative planning for anticipated intraoperative fluoroscopic inlet and outlet views within 5°. Having knowledge of the desired intraoperative views preoperatively prepares the surgeon, aids in efficiently obtaining correct intraoperative views, and ultimately assists in safe iliosacral screw placement.Level of evidenceIV, Retrospective case series.

CT-guided sacroiliac percutaneous screw placement in unstable posterior pelvic ring injuries: Accuracy of screw position, injury reduction and complications in 71 patients with 136 screws

BackgroundSacroiliac-percutaneous-screw-placement (SPSP) for unstable-posterior-pelvic-ring-injuries (UPPRI) might be associated with severe neurovascular complications because of screw-mal-position. The aim of the present study was to analysis the effectivity of computer-tomography-guided (CTG)-SPSP including accuracy of screw-placement, quality of injury-reduction and documentation of perioperative-complications. Additionally, procedure-dependent radiation-dose and outcome should be analysed. MethodsA consecutive cohort of 71 patients with UPPRI was operated by CTG-SPSP at a single trauma level 1 hospital. 136 sacroiliac screws were inserted to S1 and S2. Postoperatively, by the use of a computerised-radiologic-work-station all screws were visualised three-dimensionally. Their distancesmin to the sacral-borders in anterior-posterior and cranio-caudal direction as well as to the neuroforamen S1/S2 were determined. After CTG-SPSP, injury-dislocation in anterior-posterior and cranio-caudal direction was quantified. Local and general complications were documented during the 30-day-period. In 55 patients (77.5%) a follow-up-investigation (29.1±19.1 months) was performed. Results132 screws (97.1%) were placed completely intraosseous, 3 screws (2.2%) perforated up to 1.0mm (n(S1)=one screw; n(S2)=two screws), and one screw (0.7%) extended 2.2mm into the S2-neuroforamen without contact to neural structures. Postoperative dislocationanterior-posterior was 1.3±0.9mm and dislocationcranio-caudal 1.5±0.9mm. No procedure-associated-complication was observed. Operation time showed a significant “learning curve” during the six-year study period (initially: 88.6±60.3min; finally: 44.3±24.6min). Perioperative effective-radiation-dose for patientsmale was 5.9±3.1mSv and for patientsfemale 8.7±4.5mSv. All injuries healed and 33 patients (46.5%) had metal removal after 11.0 (±4.9) months. Only two (5.0%) out of 40 patients complained persistent UPPRI-related pain so they were not able to restart work. ConclusionsThe CTG-SPSP is a safe procedure for UPPRI-stabilisation especially in S1 but also in S2. Injury reduction was excellent and no procedure associated complications were observed.

Anatomical conditions of the posterior pelvic ring regarding bisegmental transverse sacroiliac screw fixation: a 3D morphometric study of 125 pelvic CT datasets.

Sacroiliac (SI) screws are used for osteosynthesis in unstable posterior pelvic ring injuries. In the cases of "sacral dysplasia", in which the elevated upper sacrum does not allow a secure SI screw insertion into the S1 level, the S2 segment must be used to achieve stable fixation. The bone quality of the S2 segment is thinner compared to that of the S1 vertebra and may cause biomechanical weakness. An additional SI screw insertion into the S3 level may improve stability. With respect to the anatomical conditions of the posterior pelvic ring, there have been no anatomical investigations to date regarding SI screw placement into the third sacral segment. CT raw datasets from 125 patients (ø59 years, ø172 cm, ø76 kg) were post-processed using Amira 5.2 software to generate 3D pelvic models. A program code implemented in C++ computed a transverse bone corridor for the first, second and third sacral segments for a typical SI screw diameter of 7.3 mm. Volume, sagittal cross-section, iliac entrance area and length of the determined screw corridors were measured. A confidence interval of 95 % was assumed (p < 0.05). The fully automatic computation revealed a possible transverse insertion for one 7.3-mm screw in the third sacral segment in 30 cases (24 %). The rate (60 %) of feasible S3 screw placements in the cases of sacral dysplasia (n = 25) is significantly higher compared to that (15 %) of "normal" sacra (n = 100). With regard to the existence of transverse iliosacroiliac corridors as a function of sacral position in between the adjacent iliac bone bilaterally, a new classification of three different shape conditions can be made: caudad, intermediate minor, intermediate major, and cephalad sacrum. Gender, age, body height and body weight had no statistically significant influence on either possible screw insertion or on the calculated data of the corridors (p > 0.05). SI screw insertion into the third sacral level deserves discussion in the cases of sacral dysplasia. Biomechanical and practical utility must be verified.

Technical and clinical outcome of percutaneous CT fluoroscopy-guided screw placement in unstable injuries of the posterior pelvic ring.

To evaluate technical success, complications, and effective dose in patients undergoing CT fluoroscopy-guided iliosacral screw placement for the fixation of unstable posterior pelvic ring injuries. Our retrospective analysis includes all consecutive patients with vertical sacral fractures and/or injury of the iliosacral joint treated with CT fluoroscopy-guided screw placement in our department from 11/2005 to 03/2013. Interventions were carried out under general anesthesia and CT fluoroscopy (10-20mAs; 120kV; 16- or 128-row scanner, Siemens Healthcare, Erlangen, Germany). Technical outcome, major and minor complications, and effective patient dose were analyzed. We treated 99 consecutive patients (mean age 53.1 ± 21.7years, 50 male, 49 female) with posterior pelvic ring instability with CT fluoroscopy-guided screw placement. Intervention was technically successful in all patients (n = 99). No major and one minor local complication occurred (1%, secondary screw dislocation). General complications included three cases of death (3%) due to pulmonary embolism (n = 1), hemorrhagic shock (n = 1), or cardiac event (n = 1) during a follow-up period of 30days. General complications were not related to the intervention. Mean effective patient radiation dose per intervention was 12.28mSv ± 7.25mSv. Mean procedural time was 72.1 ± 37.4min. CT fluoroscopy-guided screw placement for the treatment of posterior pelvic ring instabilities can be performed with high technical success and a low complication rate. This method provides excellent intrainterventional visualization of iliac and sacral bones, as well as the sacral neuroforamina for precise screw placement by applying an acceptable effective patient dose.

Displaced inferior ramus fractures as a marker of posterior pelvic injury.

Injuries to the anterior or posterior pelvic ring rarely occur in isolation. Disruption to the anterior pelvic ring, indicated by a fracture of the superior or inferior pubic ramus, or injury to the pubic symphysis, may be indicative of additional pelvic ring disruption. The purpose of this retrospective study was to determine whether displaced inferior pubic ramus fractures warrant a more detailed investigation of the posterior ring in an effort to predict unstable posterior pelvic ring injuries. All patients with a displaced inferior ramus fracture on AP pelvic radiograph were identified at a single level I trauma center over a 5-year period. Complete pelvic radiographs and computed tomography scans were then evaluated for additional pelvic ring injuries. The data were analyzed using the chi-square test to determine the association between inferior ramus fractures and posterior pelvic ring injury. Sixty-three of the 93 patients with a fracture of the inferior ramus (68 %) were found to have a posterior ring injury; 60 % of these injuries were unstable. Patients with concurrent superior ramus fractures were more likely to have a posterior ring injury (p < 0.001) and an unstable pelvis (p = 0.018). Of those with a displaced unilateral inferior ramus fracture, parasymphyseal involvement was associated with higher incidence of posterior ring injury (p = 0.047) and pelvic instability (p = 0.028). The anterior pelvic ring can be used to help identify unstable injuries to the posterior pelvis. Patients with displaced inferior pubic ramus fractures warrant a detailed examination of their posterior ring to identify additional injuries and instability.

The posterior approach to pelvic ring injuries: A technique for minimizing soft tissue complications

Surgical techniques and fixation strategies for the treatment of unstable posterior pelvic ring injuries continue to evolve. The safety of the posterior surgical approach in particular has been questioned due to historically high rates of wound related complications. More contemporary studies have shown lower infection rates, however concern still persists. These concerns for infection and wound necrosis have led, in part, to increased interest in closed reduction and percutaneous fixation for treatment of these injuries but an open posterior approach remains the optimal strategy in some injury patterns. We describe herein a modified posterior approach to the pelvis designed to minimize wound related complications and present our clinical results demonstrating wound complication rates consistent with contemporary publications.

Outcome analysis of unstable posterior ring injury of the pelvis: Comparison between percutaneous iliosacral screw fixation and conservative treatment

Unstable posterior ring injuries of the pelvis are a challenge to pelvic surgeons, and their treatment has been controversial. The functional outcomes of such injuries following either percutaneous iliosacral screw fixation or conservative treatment remain to be elucidated. We conducted a retrospective analysis of 32 consecutive patients with unstable pelvic ring injuries who were treated with percutaneous placement of iliosacral screws (group 1) or conservative means (group 2) from January 2002 to September 2009. Radiographic, clinical, and functional outcomes were compared between the two treatment groups. Patients who underwent percutaneous iliosacral screw fixation after pelvic trauma had better functional results than those treated conservatively, as per the Majeed grading system. In addition, patients in group 1 demonstrated better results for general health and mental health on the 36 item Short Form Health Status Survey. Patients in group 1 also demonstrated less residual displacement on radiography at 1 year follow up than those in group 2. Finally, patients in group 1 had better pain relief at 1 month and 1 year follow ups than those in group 2. Percutaneous iliosacral screw fixation for unstable posterior pelvic ring injuries results in less residual displacement at medium term follow up, and better pain relief at short and medium term follow up, than does conservative treatment. Better functional outcomes were observed at 1 year follow up as compared with conservative treatment.

Anterior reconstruction plate fixation for unstable posterior pelvic ring injuries

Objective To discuss the surgical indications,relative merits and clinical outcomes of anterior reconstruction plate fixation for treating unstable posterior pelvic ring injuries. Methods A retrospective study was done on clinical data of 36 patients with unstable posterior pelvic ring injuries treated with anterior reconstruction plate fixation from August 2004 to July 2010 and followed up for minimum one year.There were 25 males and 11 females,at mean age of 35.8 years ( range,13-62 years).There were two patients with anterior dislocation of the sacroiliac joint and 34 with posterior dislocation.According to Tile classification,there were four patients with type B fractures ( B1:3,B2:1 ) and 32 with type C fractures (C1-1:17,C1-2:12,C2:2,C3:1 ). Results All patients were followed up for average 2.3 years ( range,1-6 years).Fat liquefaction and superficial infection were founded in two patients who were cured by dressing change and frequent but low-dose blood transfusion.Eight patients were subjected to iatrogenic lateral femoral cutaneous nerve injury.Meanwhile,five of them was recovered after treatment with neurotrophic drugs,but there were still three patients leaving lateral thigh numbness.One patient had L5 nerve root injury due to pull force,and was recovered after three months of neurotrophic drug therapy.According to Matta and Tometta criteria,the reduction results were excellent in 23 patients,good in 11 and fair in four,with excellence rate of 94％.No reduction loss or implant failure occurred.According to Majeed scoring system,the clinical outcomes were excellent in 17 patients,good in 14,fair in four and poor in one,with excellence rate of 86％.Of the seven patients pre-operatively associated with sacral plexusinjury,three obtained full recovery,two got partial recovery and two were free from recovery. Conclusion The anterior reconstruction plate fixation takes advantages of wide surgical indications,simple exposure,low infection rate,satisfactory reduction and solid fixation and may be a main treatment method for unstable posterior pelvic ring injuries. Key words: Pelvis; Fracture fixation, internal; Treatment outcome

Pediculo-Iliac Screw Fixation in Vertically Unstable Posterior Pelvic Ring Injury

Pediculo-Iliac Screw Fixation in Vertically Unstable Posterior Pelvic Ring Injury

Iliosacral Screw Placement: Are Uniplanar Changes Realistic Based on Standard Fluoroscopic Imaging?

With the aim of improving the understanding of iliosacral screw placement, two hypotheses were tested: (1) standard intraoperative inlet and outlet images are not based on orthogonal coordinates, and (2) therefore making starting point and aim changes by moving perpendicular to the c-arm beam will displace the guide wire on the other intraoperative radiographic view. This is a prospective case series with review of intraoperative data from consecutive patients treated at a University Level I trauma center. The study group included ten consecutive patients with nondysmorphic upper sacral segments and unstable posterior pelvic ring injuries that required surgical treatment. Posterior surgical stabilization included iliosacral screw placement using a standardized three- view technique in the supine position. The main outcome measurement included the angles from the perpendicular required to achieve what have been considered the ideal inlet and outlet views intraoperatively. The angle arc for each patient created by the recorded angles was then determined. The average sagittal plane tilt required to achieve the ideal inlet view was 25 degrees (range, 21-33 degrees). The average sagittal plane tilt required to achieve the ideal outlet view was 42 degrees (range, 30-50 degrees). The average arc between the ideal inlet and outlet views was 67 degrees (range, 62-76 degrees). These views never created an orthogonal system. We commonly work in orthogonal systems. Within these systems, it is possible to make a uniplanar correction by moving perpendicular to one plane or radiographic view. The ideal views to image the safe zone for iliosacral screw placement do not create an orthogonal system. When this average angle arc is placed on a graphic model of the pelvis, it becomes clear that the plane of the radiographic beam of the ideal inlet view is collinear with the anterior aspect of the upper two sacral bodies. The outlet view is oblique to the upper sacral bodies. Surgeons must keep this in mind when using fluoroscopic views to insert iliosacral screws.

Prevalence of sacral dysmorphia in a prospective trauma population: Implications for a "safe" surgical corridor for sacro-iliac screw placement

BackgroundPercutaneous sacro-iliac (SI) screw fixation represents a widely used technique in the management of unstable posterior pelvic ring injuries and sacral fractures. The misplacement of SI-screws under fluoroscopic guidance represents a critical complication for these patients. This study was designed to determine the prevalence of sacral dysmorphia and the radiographic anatomy of surgical S1 and S2 corridors in a representative trauma population.MethodsProspective observational cohort study on a consecutive series of 344 skeletally mature trauma patients of both genders enrolled between January 1, 2007, to September 30, 2007, at a single academic level 1 trauma center. Inclusion criteria included a pelvic CT scan as part of the initial diagnostic trauma work-up. The prevalence of sacral dysmorphia was determined by plain radiographic pelvic films and CT scan analysis. The anatomy of sacral corridors was analyzed on 3 mm reconstruction sections derived from multislice CT scan, in the axial, coronal, and sagittal plane. "Safe" potential surgical corridors at S1 and S2 were calculated based on these measurements.ResultsRadiographic evidence of sacral dysmorphia was detected in 49 patients (14.5%). The prevalence of sacral dysmorphia was not significantly different between male and female patients (12.2% vs. 19.2%; P = 0.069). In contrast, significant gender-related differences were detected with regard to radiographic analysis of surgical corridors for SI-screw placement, with female trauma patients (n = 99) having significantly narrower corridors at S1 and S2 in all evaluated planes (axial, coronal, sagittal), compared to male counterparts (n = 245; P < 0.01). In addition, the mean S2 body height was higher in dysmorphic compared to normal sacra, albeit without statistical significance (P = 0.06), implying S2 as a safe surgical corridor of choice in patients with sacral dysmorphia.ConclusionsThese findings emphasize a high prevalence of sacral dysmorphia in a representative trauma population and imply a higher risk of SI-screw misplacement in female patients. Preoperative planning for percutaneous SI-screw fixation for unstable pelvic and sacral fractures must include a detailed CT scan analysis to determine the safety of surgical corridors.

Early Results of Percutaneous Ilioscral Screw Fixation in Unstable Posterior Pelvic Ring Injury

Early Results of Percutaneous Ilioscral Screw Fixation in Unstable Posterior Pelvic Ring Injury

Outcome of operatively treated unstable posterior pelvic ring disruptions.

Forty-six patients with 48 operatively fixed unstable posterior pelvic ring disruptions were observed for an average of 44 months. Two thirds of the patients returned to their original jobs and 16% changed jobs because of an associated injury. Sixty-three percent of the patients had no pain or pain only on strenuous activity and ambulated without limitation. However, 35% of the patients had significant neurologic injuries that compromised their final result. Properly performed open reduction and internal fixation of unstable posterior pelvic ring injuries may he expected to yield good functional results in the majority of patients. Associated injuries continue to be a major source of disability.

Outcome after fixation of unstable posterior pelvic ring injuries.

Between June 1989 and May 1995, the authors surgically treated 64 patients with unstable posterior pelvic in juries. Fracture types included Tile Type C1 (75%), C2 (8%), and C3 (17%). There were 19 sacroiliac dislocations, 12 sacral fractures, 4 transiliac fractures, and 29 sacroiliac fracture dislocations. Average patient age was 32 years and Injury Severity Score was 27 points. Posterior fixation was accomplished by percutaneous iliosacral screw insertion in 53 patients (83%). Only pure transiliac fractures were treated without iliosacral screws. There were no iatrogenic nerve palsies. During the study, there was increased reliance on internal fixation of the anterior pelvic ring that aided in anatomic alignment of the pelvis for posterior fixation and resulted in decreased chronic pubic tenderness. The use of external fixation for definitive treatment was abandoned. Patients were observed for an average of 36 months (range, 5-74 months). Fifty-two patients were available for recent complete followup. Fifty-one patients (98%) healed their pelvic disruptions; there was 1 sacral nonunion. A 40-point pelvic outcome grading scale was developed based on physical examination, pain, radiographic analysis, and activity/work status. Scores obtained by this scale correlated closely with the Short Form-36 Health Survey scores. Patient functional outcome after posterior pelvic fracture was not associated with Injury Severity Score or fracture location.

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

Open reduction and internal fixation of unstable posterior pelvic ring injury provides better bony stability and less long term morbidity than nonoperative treatment. However, open reduction and internal fixation of the posterior pelvis may involve substantial intraoperative blood loss, reported infection rates of 6 to 25%, and wound complications in 25%. Our hypothesis was that percutaneous cannulated iliosacral screws placed by fluoroscopic control would provide early, rapid, definitive stabilization with minimal blood loss, infection, and wound complications. A retrospective medical record and radiographic study. MATERIALS, METHODS, MEASUREMENTS AND MAIN RESULTS: Twenty consecutive patients with an unstable posterior pelvic ring injury treated by percutaneous fixation (41 screws) under fluoroscopic guidance were reviewed. Average patient age was 34 years, trauma score was 14.4 +/- 3.3, and Injury Severity Score was 22.9 +/- 10.6. Mechanisms were motor vehicle collisions (11), falls (3), crush injury (3), and pedestrian/auto (3). Pelvic injuries were classified as Tile B (5) or Tile C (15). Associated injuries were present in 80%. Seventy-five percent of patients underwent pelvic fixation less than 72 hours after injury with closed percutaneous screw placement achieved in 60%, assisted by open reduction in 25% or aided by anterior external fixation in 15%. Mean operative time was 52 minutes for patients requiring percutaneous screws only (7 of 20 patients, 35%), whereas average blood loss was 233 mL for all cases (including open anterior and posterior procedures). No loss of fixation or wound complications occurred during 9.6 months follow-up. Percutaneous iliosacral screw fixation for unstable posterior pelvic disruption provided early fixation with minimal operative time, minimal blood loss, and wound-related morbidity.