Stable Lateral Compression Pelvic Ring Injury Requiring Operative Treatment due to Bladder Impingement: A Case Report.

CASE: A 25-year-old man sustained a stable lateral compression Type I (LC I) pelvic ring injury upon missing the landing of a downhill ski jump. He presented with painful voiding from a displaced bony fragment, partially impaling the bladder wall. With operative fixation of the fracture and urologic co-management, the patient had excellent outcomes at 1-year follow-up. CONCLUSION: We describe a rare urologic injury in the setting of an LC I pelvic ring injury. In the setting of an otherwise stable pelvic ring injury, careful review of imaging, detailed clinical history, and physical examination remain critical to optimizing patient outcomes.

For Surgically Treated Geriatric Acetabular Fractures, Longer Duration between Admission and Surgery Is Associated with an Increase in Post-operative Complications: A Study Using the National Trauma Data Bank.

INTRODUCTION: The purpose of this study was to determine whether time from hospital admission to surgery is associated with inpatient complications and mortality for geriatric patients undergoing surgical treatment of acetabular fractures. METHODS: This was a retrospective cohort study using the National Trauma Data Bank from 2016 to 2018 of patients presenting to level I through IV trauma centers in the United States. All patients aged 60 years or older with acetabular fractures requiring surgical treatment were included. The main outcome measurements were inpatient mortality and complication rates. RESULTS: There were 6,036 patients who met inclusion criteria. The median age was 69 years (interquartile range 64-76 years). The odds of a complication increased by 7% for each additional day between hospital admission and surgery (multivariable regression OR 1.07, 95% CI = 1.04 to 1.10; P < 0.001). Complications were also associated with patient age (OR 1.05, 95% CI = 1.03 to 1.06; P < 0.001) and mCCI ≥ 5 (OR 2.52, 95% CI = 1.4 to 4.2; P = 0.001). Inpatient mortality was not associated with time to surgery (OR 0.97, 95% CI = 0.92 to 1.02; P = 0.30), but was associated with patient age (OR 1.07, 95% CI = 1.05 to 1.10; P < 0.001; P < 0.001) and mCCI ≥ 5 (OR 4.62, 95% CI = 2.31 to 8.50; P < 0.001). DISCUSSION: In this database study, time from hospital admission to surgery was associated with a notable increase in inpatient complications but not inpatient mortality after adjusting for potentially confounding variables while age and mCCI were associated with both mortality and complications. Additional research is needed to determine the relationship between time to surgery with longer term mortality and complications and to assess causality. LEVEL OF EVIDENCE: Prognostic Level III.

The EMS stress view: occult pelvic instability revealed by pre-hospital pelvic binder placement.

PURPOSE: To describe and evaluate the serendipitous pelvic binder stress radiographs of lateral compression type (LC) pelvic ring injuries. METHODS: This was a retrospective case series performed at a single, level I academic trauma center from 2016 to 2018. All patients presenting with a minimally displaced LC pelvic ring injury were reviewed (< 10 cm displacement on static pelvic radiographs). Patients with X-rays (XR) in a pelvic binder (EMS stress) and with the pelvic binder removed were included. Pelvic ring stability was determined by attending surgeon evaluation of EMS stress radiographs versus static XR of the pelvis. Patients were treated non-operatively and allowed to weight bear or taken to the operating room for exam under anesthesia (EUA) and potential operative fixation. Clinical success of treatment was determined by evaluation of further displacement at the completion of their most recent follow-up. RESULTS: Thirty-seven patients of the initial 398 reviewed met inclusion criteria. Fourteen of 37 patients (38%) were categorized as stable with no significant pelvis displacement seen on EMS stress and were treated non-operatively without further sequelae (4.6 months mean follow-up). The remaining 23/37 (62%) were treated operatively. Occult instability was identified on EMS stress in 14 (61%) of those 23 patients and the remainder were determined to be unstable based upon fracture pattern or EUA. All patients went on to successful treatment without significant pelvic deformity (7.8 months mean follow-up). CONCLUSION: The EMS stress XR is a valuable, opportunistic evaluation in LC pelvic ring injuries. This evaluation is a useful diagnostic adjunct to alert the provider that additional stress imaging may be indicated to evaluate for occult pelvic ring instability.

Bridge Plate Fixation of Distal Femur Fractures: Defining Deficient Radiographic Callus Formation and Its Associations.

OBJECTIVE: To determine whether deficient early callus formation can be defined objectively based on the association with an eventual nonunion and specific patient, injury, and treatment factors. METHODS: Final healing outcomes were documented for 160 distal femur fractures treated with locked bridge plate fixation. Radiographic callus was measured on postoperative radiographs until union or nonunion had been declared by the treating surgeon. Deficient callus was defined at 6 and 12 weeks based on associations with eventual nonunion through receiver-operator characteristic analysis. A previously described computational model estimated fracture site motion based on the construct used. Univariable and multivariable analyses then examined the association of patient, injury, and treatment factors with deficient callus formation. RESULTS: There were 26 nonunions. The medial callus area at 6 weeks <24.8 mm 2 was associated with nonunion (12 of 39, 30.8%) versus (12 of 109, 11.0%), P = 0.010. This association strengthened at 12 weeks with medial callus area <44.2 mm 2 more closely associated with nonunion (13 of 28, 46.4%) versus (11 of 120, 9.2%), P <0.001. Multivariable logistic regression analysis found limited initial longitudinal motion (OR 2.713 (1.12-6.60), P = 0.028)) and Charlson Comorbidity Index (1.362 (1.11-1.67), P = 0.003) were independently associated with deficient callus at 12 weeks. Open fracture, mechanism of injury, smoking, diabetes, plate material, bridge span, and shear were not significantly associated with deficient callus. CONCLUSION: Deficient callus at 6 and 12 weeks is associated with eventual nonunion, and such assessments may aid future research into distal femur fracture healing. Deficient callus formation was independently associated with limited initial longitudinal fracture site motion derived through computational modeling of the surgical construct but not more routinely discussed parameters such as plate material and bridge span. Given this, improved methods of in vivo assessment of fracture site motion are necessary to further our ability to optimize the mechanical environment for healing. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Erectile dysfunction after acetabular fracture.

Objectives: To determine the rate of erectile dysfunction in male patients who have sustained an acetabular fracture with no previously identified urogenital injury. Design: Cross-sectional survey. Setting: Level 1 Trauma Center. Patients/Participants: All male patients treated for acetabular fracture without urogenital injury. Intervention: The International Index of Erectile Function (IIEF), a validated patient-reported outcome measure for male sexual function, was administered to all patients. Main Outcome Measurements: Patients were asked to complete the International Index of Erectile Function score for both preinjury and current sexual function, and the erectile function (EF) domain was used to quantify the degree of erectile dysfunction. Fractures were classified according the OTA/AO classification schema, fracture classification, injury severity score, race, and treatment details, including surgical approach were collected from the database. Results: Ninety-two men with acetabular fractures without previously diagnosed urogenital injury responded to the survey at a minimum of 12 months and an average of 43 ± 21 months postinjury. The mean age was 53 ± 15 years. 39.8% of patients developed moderate-to-severe erectile dysfunction after injury. The mean EF domain score decreased 5.02 ± 1.73 points, which is greater than the minimum clinically important difference of 4. Increased injury severity score and associated fracture pattern were predictive of decreased EF score. Conclusion: Patients with acetabular fractures have an increased rate of erectile dysfunction at intermediate-term follow-up. The orthopaedic trauma surgeon treating these injuries should be aware of this as a potential associated injury, ask their patients about their function, and make appropriate referrals. Level of Evidence: III.

Defining Posterior Wall Fragments in Associated Both Column Acetabular Fractures (OTA/AO 62C).

OBJECTIVE: Associated both column acetabular fractures (OTA/AO 62C) with concomitant posterior wall fracture fragments (ABC + PW) have not been well-defined. The purpose of this study was to report on the incidence and morphology of ABC + PW fractures. METHODS: A retrospective review of associated both column (ABC) fractures between 2014 and 2020 was performed. Computed tomography scans including 3-D surface rendered reformats for each were reviewed to determine whether a posterior wall (PW) fragment was present and its morphologic characteristics. RESULTS: One hundred fifty-two ABC fractures were identified. Sixty-two fractures (41%) were identified as ABC + PW. 3D-computed tomographies were available on 58 fractures. Morphologic analysis was performed based on the relationship of the fracture to the gluteal pillar. Twenty PW fragments were posterior to the gluteal pillar, 19 extended into the gluteal pillar, and 19 extended anterior. Fifty-two fractures were treated with operative fixation; 32 (62%) were clamped and fixed with screws from the same anterior approach whereas 15 (29%) required a separate posterior approach; and no fixation was placed in 5 (9%). 29 of 32 PW fragments (91%) requiring fixation that extended into or anterior to the pillar were fixed from the anterior approach, and 7 of 15 posterior fractures (47%) required a separate posterior approach. CONCLUSIONS: A separate PW fragment was identified in 41% of ABC fractures. Their variation in morphology can be classified into 3 types based on the relation to the gluteal pillar that has potential implications for treatment from the anterior approach compared with requiring a separate posterior approach. We suggest these data could be used to update the 2018 OTA/AO Fracture Compendium. LEVEL OF EVIDENCE: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Implementing an Educational Module for Orthopaedic Residents Placing Skeletal Traction.

INTRODUCTION: Although placement of a distal femoral traction (DFT) pin is a relatively simple procedure used to stabilize femoral and pelvic fractures, it places patients at risk of iatrogenic vascular, muscular, or bony injury. We designed and implemented an educational module combining theory and practical experience to standardize and improve resident teaching on the placement of DFT pins. METHODS: We introduced a DFT pin teaching module into our second-year resident "boot camp," which is used to help prepare residents for taking primary call in the emergency department at our level I trauma center. Nine residents participated. The teaching module included a written pretest, an oral lecture, a video demonstration of the procedure, and a practice simulation on 3D printed models. After completing the teaching, each resident underwent a written examination and proctored live simulation involving 3D models using the same equipment available in our emergency department. Pre-teaching and post-teaching surveys were used to assess resident experience and confidence with placing traction in the emergency department. RESULTS: Before the teaching session, the rising postgraduate year 2 residents scored an average of 62.2% (range, 50% to 77.8%) on the DFT pin knowledge quiz. This improved to an average of 86.6% (range, 68.1% to 100%) (P = 0.0001) after the teaching session. After completing the educational module, they also demonstrated an improvement in confidence with the procedure, from 6.7 (range, 5 to 9) to 8.8 (range, 8 to 10) (P = 0.04). DISCUSSION: Despite reporting high levels of confidence in their ability to place traction pins before starting the postgraduate year 2 consult year, many residents also reported anxiety around the accurate placement of traction pins. Early results of our training program showed improved resident knowledge of safe placement of traction pins and improved confidence with the procedure.

Immediate Fixation of Acetabular Fractures Through an Anterior Approach Does Not Increase Morbidity or Mortality.

INTRODUCTION: Acetabular fractures requiring an anterior approach have historically been delayed, allowing a stable clot to form before creating large surgical exposures. The purpose of this study was to determine whether immediate fixation of acetabular fractures within 24 hours using an anterior approach demonstrates notable difference in blood loss, length of stay (LOS), complications, or mortality compared with acetabular fractures treated after 24 hours. METHODS: Ninety-three patients were optimized for surgery within 24 hours of injury. Thirty-two patients underwent fixation within 24 hours using an anterior approach to the acetabulum. Demographics, hours from injury to operating room, fracture classification, embolization, surgical approach, intraoperative cell salvage use, Charlson Comorbidity Index, American Society of Anesthesiologists class, Injury Severity Score, and Abbreviated Chest Injury Score were recorded. Estimated blood loss, transfusions, intensive care unit stay, total hospital LOS, complications, and mortality rates were compared. RESULTS: No statistically significant differences were observed in fracture classification, blood loss, or intraoperative transfusions between the immediate and delayed fixation groups. Six patients in the delayed group (9.8%) returned to the operating room for a complication compared with one patient (3.1%) in the immediate group ( P = 0.42). Three patients in the delayed group (4.9%) developed a surgical site infection compared with none (0%) in the immediate group ( P = 0.55). The immediate group had an average LOS of 7 days compared with 11 days in the delayed fixation group ( P = 0.01). No notable differences were observed in 30- or 90-day mortality rates. DISCUSSION: Medically optimized patients with acetabular fractures who undergo immediate fixation through an anterior approach do not seem to have an associated increase in blood loss, transfusions, or mortality. Prompt surgical management may also be associated with a shorter preoperative and postoperative LOS. LEVEL OF EVIDENCE: Therapeutic level III.

Type III Open Tibia Fractures Treated With Single-Stage Immediate Medullary Nailing and Attempted Primary Closure Yield Low Rates of Flap Coverage.

OBJECTIVE: The purpose of this study was to determine whether type III open high-energy tibia fractures treated with immediate intramedullary nailing (IMN) and primary closure yield low rates of flap coverage. METHODS: Patients with high-energy type IIIA open tibia (OTA/AO42/43) fractures treated with IMN over a 10-year period at a level 1 academic center with at least 90 days of in-person postoperative follow-up were included. Single-stage reamed IMN with acute primary skin closure using Allgower-Donati suture technique was utilized in patients without notable skin loss. The primary outcome was treatment failure of acute primary skin closure requiring subsequent soft-tissue coverage procedures. RESULTS: A total of 111 patients with type IIIA tibia fractures met inclusion criteria. Of 107 of the 111 patients (96%) with skin closure at the index surgery, 95 of the 107 patients (89%) healed their soft-tissue envelop uneventfully. Among the patients who failed primary closure (11%), five required free tissue transfers, five required local rotational flaps, and two underwent split thickness skin grafting only. Patients who failed acute primary closure declared within an average of 8 weeks postoperatively. DISCUSSION: Treatment of type IIIA open high-energy tibia fractures with immediate IMN and primary closure using meticulous soft-tissue handling yields low rates of flap coverage.

Assessment of regional sacral bone quality: A step towards patient-specific fracture fixation.

Characterizing changes in sacral bone density could help us to inform instrumentation choices for procedures involving the sacrum. The aim of this study is to provide detailed maps of changes in sacral bone density across a series of patients using opportunistic quantitative computed tomography (QCT). We hypothesized that there would be significant differences in local cortical and trabecular bone density associated with age and sex. Fifty-four three-dimensional sacral models were segmented from routine clinical computed tomography scans, and detailed bone density estimates were derived for each bone using a calibrated opportunistic QCT approach. The effects of age and sex on cortical and trabecular bone density were determined across the sample. Overall cortical bone loss averaged 2.1 and 0.9 mg/cc per year, and trabecular bone loss was 1.6 and 0.7 mg/cc for female and males, respectively. Several regions had loss rates several times greater. Areas that were significantly affected by age included the vertebral bodies, bilateral ala, apex, and areas adjacent to both the anterior and posterior sacral foramina. Areas that were significantly affected by sex were the anterior sacral promontory, aspects of the ala. Bone density distribution across the sacrum changes nonuniformly due to factors including sex and age. Despite these overall trends, there remains significant variability between individuals. Clinical significance: This study provides detailed bone density information for both cortical and trabecular bone that could assist orthopaedic surgeons in planning surgical approaches to sacral fracture fixation.

Quantification and visualization of anterior pelvis bone density to optimize screw fixation: A novel technique.

Plate fixation of anterior pelvic ring fractures is often a vital component when surgically treating unstable pelvis fractures. Certain plate and screw configurations can have premature implant loosening, potentially in part due to insufficient pullout strength in lower density bone. This study sought to define densities about the anterior pelvic ring using a novel computer-based technique. Thirty-three patients who received a computed tomography (CT) of the abdomen/pelvis for reasons other than pelvis fracture in a 1-month time period were included. Three statistically distinct density regions of the anterior pelvis were identified based on the three-dimensional (3D) density map. The densest regions included both the anterior and posterior aspects of the superior pubic ramus, along with the region of bone along the inferior cotyloid fossa. The intermediate density region included the caudal and medial pubic body. The least dense region included the anterior aspect of the inferior pubic ramus (IPR), the posterior pubic body, and the posterior/inferior IPR. This study presents specific quantification of anterior pelvis bone density based on a novel technique using opportunistic CT scans. Clinical Significance: Anterior surgical fixation of unstable pelvic ring injuries may benefit from targeting areas of higher density as described in this novel technique.

Syndesmosis Malposition Assessed on Weight-Bearing CT Is Common After Operative Fixation of Intra-articular Distal Tibia Plafond Fracture.

OBJECTIVES: To evaluate reliability of measurement techniques for syndesmosis position after operative fixation of distal tibia plafond fracture on weight-bearing computed tomography (WBCT), identify risk factors for syndesmosis malposition, and determine if syndesmosis malposition is associated with higher pain and lower physical function. DESIGN: Prospective cohort study. SETTING: Three Level 1 trauma centers. PARTICIPANTS: Twenty-six subjects who underwent open reduction and internal fixation of distal tibia plafond fractures with bilateral ankle WBCT 1 year or greater after injury were included in the study. INTERVENTION: Operative fixation of distal tibia plafond fracture. MAIN OUTCOME MEASUREMENT: Fibula position in the tibia incisura, injury characteristics, and patient-reported outcomes were the main outcome measurements. RESULTS: Interrater reliability for syndesmosis position measurements were excellent for the Phisitkul technique on both injured and healthy ankles (intraclass correlation coefficients [ICCs]: 0.93-0.98). The Nault technique demonstrated moderate-to-excellent interrater reliability (ICCs: 0.67-0.98), apart from the angle of rotation measurement (ICCs: 0.18-0.67). Sixteen of 26 subjects (62%) had syndesmosis malposition defined as >2 mm difference comparing the tibial-fibular relationship in injured and uninjured ankles using these 2 methods. Patients with syndesmosis malposition reported lower Foot and Ankle Ability Measure: Activities of Daily Living scores; other recorded patient-reported outcomes were not significantly different. CONCLUSIONS: Measurement techniques for syndesmosis position on WBCT were reliable after operative fixation of distal tibia plafond fracture. Syndesmosis malposition is common after these injuries and predicted impaired physical function. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Pelvic Ring Resuscitation Pathways.

CLINICAL VIGNETTE: A 35 year-old female is injured in a high-speed motor vehicle collision in which her car is struck on the driver's side by a distracted driver. The patient is unable to self-extricate from the vehicle and she is confused at the scene. She comes directly to the trauma bay via EMS and a binder is placed in transit for suspicion of a pelvic ring injury. Upon presentation she has a GCS of 14 due to confusion, and an initial pressure of 87/50. Workup does not disclose an associated head, chest or abdominal injury and the anteroposterior pelvis radiograph demonstrates a windswept pelvis injury pattern. Despite being transfused 4 units of whole blood, her hypotension does not improve. Please describe your institution's advanced resuscitation protocol and management of this scenario, and provide the rational and support for it.

Novel Technique for Percutaneous Reduction of Displaced LCII Pelvic Ring Injury: A Case Report.

CASE: We present a case report of an elderly patient with a displaced lateral compression type II pelvic ring injury and describe a novel technique for maintaining a percutaneously obtained reduction during percutaneous fixation using a supra-acetabular Schantz pin attached to a mechanical limb positioner. CONCLUSION: The mechanical limb positioner used allows the surgeon to hold a multidirectionally obtained reduction of the hemipelvis with ease.

Long-Term Consequences of Major Extremity Trauma: A Pilot Study.

SUMMARY: Limited data are available on the longer-term physical and psychosocial consequences after major extremity trauma apart from literature on the consequences after major limb amputation. The existing literature suggests that although variations in outcome exist, a significant proportion of service members and civilians sustaining major limb trauma will have less than optimal outcomes or health and rehabilitation needs over their life course. The proposed pilot study will address this gap in current research by locating and consenting METRC participants with the period of 5-7 years postinjury, identifying potential participation barriers and appropriate use of incentives, and conducting the follow-up examination at several data collection sites. The resulting data will inform the primary objective of refining and developing specific hypotheses to determine the design, scope, and feasibility of the main long-term consequences of major extremity trauma. Three METRC enrollment centers will contact past participants to achieve the goal of completing an interview, select patient-reported outcomes, perform a medical record review, and conduct an in-person clinic visit that will consist of a physical examination, blood draw, and x-ray of the study injury area. If successful, it will be possible to design studies to further examine these effects and develop future therapeutic interventions.

Streamlining Trauma Research Evaluation With Advanced Measurement (STREAM) Study: Implementation of the PROMIS Toolbox Within an Orthopaedic Trauma Clinical Trials Consortium.

LEVEL OF EVIDENCE: Prognostic Level II.

Simultaneous Posterolateral and Posteromedial Approaches for Fractures of the Entire Posterior Tibial Plafond: A Safe Technique for Effective Reduction and Fixation.

OBJECTIVE: To determine the short-term results of surgical treatment with dual posterolateral and posteromedial approaches for fractures of the entire posterior tibial plafond and secondarily to identify common fracture characteristics. DESIGN: Retrospective. SETTING: Single academic Level 1 trauma center. PATIENTS: Thirty-five patients with posterior pilon fractures followed until fracture union (minimum 3 months). INTERVENTION: Surgical treatment using simultaneous combined posterolateral and posteromedial exposures for fracture reduction and internal fixation. MAIN OUTCOME MEASUREMENT: (1) Surgical outcomes including rate of wound complications and accuracy of the articular reduction. (2) Fracture characteristics including the incidence of articular impaction, comminution interfering with reduction, syndesmosis injury, and the type of fibula fracture. RESULTS: The rate of wound problems was low (6%), and 94% of patients had an articular reduction with less than 1 mm of step or gap. There were high rates of articular comminution (83%) and posteromedial articular impaction (63%) and a 17% rate of syndesmosis injury requiring repair. CONCLUSIONS: Surgical fixation using simultaneous, combined posterolateral and posteromedial approaches for posterior pilon fractures had a low rate of wound complications and was an effective strategy for obtaining an accurate reduction. The rate of syndesmotic instability requiring fixation was lower than previous work reporting on fixation using a single approach. This may be a useful technique for surgeons who treat these injuries. Careful assessment of the preoperative imaging is required in patients with posterior pilon fractures. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Validation of the AO Spine Sacral Classification System: Reliability Among Surgeons Worldwide.

OBJECTIVES: To (1) demonstrate that the AO Spine Sacral Classification System can be reliably applied by general orthopaedic surgeons and subspecialists universally around the world and (2) delineate those injury subtypes that are most difficult to classify reliably to refine the classification before evaluating clinical outcomes. DESIGN: Agreement study. SETTING: All-level trauma centers, worldwide. PARTICIPANTS: One hundred seventy-two members of the AO Trauma and AO Spine community. INTERVENTION: The AO Sacral Classification System was applied by each surgeon to 26 cases in 2 independent assessments performed 3 weeks apart. MAIN OUTCOME MEASUREMENTS: Interobserver reliability and intraobserver reproducibility. RESULTS: A total of 8097 case assessments were performed. The kappa coefficient for interobserver agreement for all cases was 0.72/0.75 (assessment 1/assessment 2), representing substantial reliability. When comparing classification grading (A/B/C) regardless of subtype, the kappa coefficient was 0.84/0.85, corresponding to excellent reliability. The kappa coefficients for interobserver reliability were 0.95/0.93 for type A fractures, 0.78/0.79 for type B fractures, and 0.80/0.83 for type C fractures. The overall kappa statistic for intraobserver reliability was 0.82 (range 0.18-1.00), representing excellent reproducibility. When only evaluating morphology type (A/B/C), the average kappa value was 0.87 (range 0.18-1.00), representing excellent reproducibility. CONCLUSION: The AO Spine Sacral Classification System is universally reliable among general orthopaedic surgeons and subspecialists worldwide, with substantial interobserver and excellent intraobserver reliability.

AP pelvis radiograph is insufficient for diagnosis of U-type sacral fractures.

PURPOSE: We investigated the sensitivity of a screening test for pelvic ring disruption, the AP pelvis radiograph, for clinically serious U-type sacral fractures which merit consultation with an orthopedic trauma specialist and may require transfer to a higher level of care. METHODS: Retrospective clinical cohort of 63 consecutive patients presenting with U-type sacral fractures at one level 1 trauma referral center from January 2006 through December 2019. The sensitivity of the first AP pelvis radiograph obtained on admission, interpreted without reference to antecedent or concomitant pelvis computed tomography (CT) by a radiologist and a panel of three blinded orthopedic traumatologists, was determined against a reference diagnosis made from review of all pelvis radiographs, CT images, operative reports, and clinical documentation. RESULTS: Sensitivity of AP pelvis radiograph for U-type sacral fractures was 2% as interpreted by a radiologist and mean 12% (range 5-27%) as interpreted by orthopedic traumatologists with poor inter-rater agreement (Fleiss' κ = 0.11). 94% of sacra were at obscured by radiographic artifact. CONCLUSION: The sensitivity of an AP pelvis radiograph is poor for U-type sacral fractures, whether interpreted by radiologists or orthopedic traumatologists. Pelvis CT should be considered as a screening test to rule out sacral fracture when the patient reports posterior pelvic pain, even if plain radiography demonstrates no injury or a minimally displaced pelvic ring disruption. LEVEL OF EVIDENCE: Diagnostic level III.