Variables Associated With Loss of Fixation of Retrograde Rami Screws in Minimally Displaced Lateral Compression Type 1 Pelvic Ring Injuries.

OBJECTIVES: To evaluate variables associated with loss of fixation of retrograde rami screws in the treatment of stress-positive minimally displaced lateral compression type 1 (LC1) injuries. DESIGN: Retrospective comparative study. SETTING: Level 1 trauma center. PATIENT SELECTION CRITERIA: Stress-positive minimally displaced (<1 cm) LC1 pelvic ring injuries treated with retrograde rami screws. OUTCOME MEASURES AND COMPARISONS: Loss of fixation, defined as >5 mm of pelvic fracture displacement based on the radiographic tear-drop distance or >5 mm of implant displacement on follow-up radiographs; revision surgery for loss of fixation. RESULTS: Thirty-eight patients with 40 retrograde rami screws were analyzed. Median patient age was 64 years (interquartile range 42.5-73.3 years), 71.1% (n = 27/38) were female, and 52.6% (n = 20/38) of injuries were secondary to low-energy mechanisms. Loss of fixation occurred in 17.5% (n = 7/40) of screws with 10% (n = 4/40) requiring revision surgery. On univariate analysis, patients who had a loss of fixation were more likely to have greater dynamic displacement on stress radiographs (22.0 vs. 15.2 mm; median difference 5.6 mm, confidence interval [CI] -19.2 to 10.3; P = 0.04), unicortical rami screws (71.4% vs. 9.1%; proportional difference 62.3%, CI 8.8%-22.6%; P = 0.001), and partially threaded rami screws (71.4% vs. 21.2%; proportional difference 50.2%, CI 10.0%-77.6%; P = 0.01). The remaining variables had no observed association ( P ≥ 0.05) with loss of fixation, including age, sex, body mass index, energy of injury mechanism, tobacco use, American Society of Anesthesiologist score, sacral fracture type, distal rami fractures, rami comminution, number of sacral screws, fully threaded sacral screws, transsacral screws, or rami screw diameter. On multivariate analysis, only unicortical rami screws ( P = 0.01) remained associated with loss of fixation. CONCLUSIONS: Retrograde rami screws had a high rate of loss of fixation in minimally displaced LC1 pelvic ring injuries, and this was associated with unicortical screws. These screws should be avoided when possible. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Use of 3D Printing Technology in Fracture Management: A Review and Case Series.

SUMMARY: Three-dimensional (3D) offers exciting opportunities in medicine, particularly in orthopaedics. The boundaries of 3D printing are continuously being re-established and have paved the way for further innovations, including 3D bioprinting, custom printing refined methods, 4D bioprinting, and 5D printing potential. The quality of these applications have been steadily improving, increasing their widespread use among clinicians. This article provides a review of the current literature with a brief introduction to the process of additive manufacturing, 3D printing, and its applications in fracture care. We illustrate this technology with a case series of 3D printing used for correction of complex fractures/nonunion. Factors limiting the use of this technology, including cost, and potential solutions are discussed. Finally, we discuss 4D bioprinting and 5D printing and their potential role in fracture surgery.

Percutaneous pelvic fixation model: an affordable and realistic simulator for pelvic trauma training.

PURPOSE: To describe the construction and use of a percutaneous pelvic fixation model, evaluate its translational validity among fellowship-trained orthopedic trauma surgeons, and investigate the importance of specific criteria for effective competency-based assessment of pelvic fixation techniques. METHODS: Five orthopedic trauma surgeons were asked to place percutaneous wires on a pelvic fixation model, including anterior column (antegrade/retrograde), posterior column (antegrade/retrograde), supra-acetabular, transsacral, and iliosacral. Evaluation criteria included successful wire placement, redirections, cortical breaches, procedure duration, radiation exposure, and quality of fluoroscopic views. Following completion, participants were provided a survey to rate the model. RESULTS: There were no differences between approaches on successful screw placement, wire redirections, or fluoroscopic quality. Antegrade approaches to the anterior and posterior columns took longer (p = 0.008) and used more radiation (p = 0.02). There was also a trend toward more cortical breaches with the antegrade anterior column approach (p = 0.07). Median ratings among surgeons were 4 out of 5 for their overall impression and its accuracy in tactile response, positioning constraints, and fluoroscopic projections. Learning parameters considered most important to the progression of trainees (most to least important) were successful screw placement, corridor breaches, wire redirections, quality of fluoroscopic views, radiation exposure, and procedure duration. CONCLUSION: In being affordable, accessible, and realistic, this percutaneous pelvic fixation model represents an opportunity to advance orthopedic surgery education globally. Future research is needed to validate the findings of this pilot study and to expand upon how trainees should be evaluated within simulations and the operating room to optimize skill progression.

Nonoperative management of minimally displaced lateral compression type 1 (LC1) injuries with comminuted rami fractures is associated with late displacement.

PURPOSE: Rami comminution has been found to be predictive of lateral compression type 1 (LC1) injury instability on examination under anesthesia (EUA) and lateral stress radiographs (LSR). The purpose of this study was to evaluate how rami comminution and subsequent operative vs. nonoperative management impact the late displacement of these injuries. METHODS: Retrospective review of a prospectively collected LC1 database was performed to identify all patients with minimally displaced LC1 injuries (< 1 cm) and follow-up radiographs over a four-year period (n = 125). Groups were separated based on the presence of rami comminution and subsequent management, including rami comminution/operative (n = 49), rami comminution/nonoperative (n = 54), and no comminution/nonoperative (control group, n = 22). The primary outcome was late fracture displacement, analyzed as both a continuous variable and as late displacement ≥ 5 mm. RESULTS: As a continuous variable, late fracture displacement was lower in the comminuted rami/operative group as compared to the comminuted rami/nonoperative group (PD: -3.0 mm, CI: -4.8 to -1.6 mm, p = 0.0002) and statistically non-different from control. Late displacement ≥ 5 mm was significantly more prevalent in the comminuted rami/nonoperative group than in the comminuted rami/operative and no comminution/nonoperative groups (control)(PD: -33.9%, CI: -49.0% to -16.1%, p = 0.0002 and PD: -30.0%, CI: -48.2% to -6.5%, p = 0.02, respectively). CONCLUSION: Late fracture displacement was greatest in the group with rami comminution/nonoperative management. Rami comminution, which has been previously associated with dynamic displacement on EUA and LSR, is also associated with a higher incidence of late displacement when managed nonoperatively. LEVEL OF EVIDENCE: Level III, prognostic retrospective cohort study.

Early Outcomes of Operative Versus Nonoperative Management of Stress-Positive Minimally Displaced Lateral Compression Type 1 Pelvic Ring Injuries.

OBJECTIVES: To compare the early outcomes of patients with stress-positive minimally displaced lateral compression type 1 (LC1b) pelvic ring injuries managed with or without operative fixation. DESIGN: Retrospective comparison study. SETTING: Level 1 trauma center. PATIENTS/PARTICIPANTS: Forty-three patients with LC1b injuries. INTERVENTION: Operative versus nonoperative. MAIN OUTCOME MEASUREMENTS: Discharge to subacute rehabilitation (SAR); 2- and 6-week pain visual analog score, opioid use, assistive device use, percentage of normal single assessment numerical evaluation, SAR status; fracture displacement; and complications. RESULTS: The operative group did not differ in age, gender, body mass index, high-energy mechanism, dynamic displacement stress radiographs, complete sacral fractures, Denis sacral fracture classification, Nakatani rami fracture classification, follow-up length, or American Society of Anesthesiologists classification. The operative group was less likely to be using an assistive device at 6 weeks [observed difference (OD) -53.9%, 95% confidence interval (CI) -74.3% to -20.6%, OD/CI 1.00, P = 0.0005], less likely to remain in an SAR at 2 weeks (OD -27.5%, CI, -50.0% to -2.7%, OD/CI 0.58, P = 0.02), and had less fracture displacement at follow-up radiographs (OD -5.0 mm, CI, -9.2 to -1.0 mm, OD/CI 0.61, P = 0.02). There were no other differences in outcomes between treatment groups. Complications occurred in 29.6% (n = 8/27) of the operative group compared with 25.0% (n = 4/16) of the nonoperative group resulting in 7 and 1 additional procedures, respectively. CONCLUSIONS: Operative treatment was associated with early benefits over nonoperative management, including shorter time using assistive devices, less SAR use, and less fracture displacement at follow-up. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Deltoid-Sparing Modified Judet Approach: Technique and Clinical Series.

SUMMARY: Posterior approaches provide the mainstay for treatment in most of the scapula body and neck fractures, even those associated with many intraarticular variants. Several posterior approach modifications for minimizing soft-tissue damage and limiting muscular detachment, have previously been described in the literature; however, little or no clinical evidence is available specifically applied to the various approaches.In this study, we describe complete sparing of the deltoid muscle origin during the "modified Judet" approach. The modified approach as previously described detaches the deltoid origin. Deltoid sparing allows for satisfactory visualization and fixation of extra-articular scapula fractures and even some intraarticular variants. The purpose of this article was to describe the deltoid-sparing modified Judet approach and report clinical outcomes for 23 patients after surgical treatment.

The Routine Use of Running Subcuticular Closures in Orthopaedic Trauma Patients Does Not Increase Wound Complications.

OBJECTIVE: To investigate whether the routine use of running subcuticular closures (RSC) in orthopaedic trauma patients increases the rate of wound complications and reoperations. DESIGN: Retrospective comparative study. SETTING: Urban Level 1 trauma center. PATIENTS/PARTICIPANTS: Two hundred sixty-six patients undergoing orthopaedic trauma procedures between June 2020 and March 2022. INTERVENTION: Adoption of an RSC protocol where any incision/wound that could be approximated with interrupted subcuticular 2-0 monofilament sutures was closed with a running subcuticular 3-0 monofilament suture. MAIN OUTCOME MEASUREMENTS: Wound complications and subsequent reoperations. RESULTS: With adoption of the RSC protocol, 91.0% of all orthopaedic trauma procedures were closed with RSC compared with 7.5% of the historical control group. There were no observed differences in the rate of wound complications (proportional difference (PD) 6.0%, confidence interval (CI) -2.3% to 14.1%; P = 0.15) or reoperations (PD 5.2%, CI -1.9% to 12.2%; P = 0.14) between the RSC and the control group. Wound complications were not associated with RSC on univariate analysis (PD 7.2%, CI -10.0% to 24.0%; P = 0.41). On multivariate analysis, an ASA>2 (odds ratio (OR) 2.4, CI 1.0 to 5.7; P = 0.03), lower extremity injuries (OR 4.9, CI 1.3 to 17.8; P = 0.01), and open reduction internal fixation procedures (OR 2.8, CI 1.1 to 7.2; P = 0.02) were found to be independently associated with wound complications. CONCLUSION: RSC for orthopaedic trauma procedures was not associated with increased wound complications when compared a historical cohort. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Operative Management of Stress-Positive Minimally Displaced Lateral Compression Type 1 (LC1) Pelvic Ring Injuries: Analysis of Outcomes Before and After Implementation of a Departmental Stress Protocol.

OBJECTIVES: To compare the hospital course of patients with minimally displaced (<1 cm) lateral compression type 1 injuries treated before and after implementation of lateral stress radiographs (LSRs) to determine management. DESIGN: Retrospective comparative cohort. SETTING: Urban level 1 trauma center. PATIENTS/PARTICIPANTS: Isolated lateral compression type 1 injuries managed before (n = 33) and after implementation of LSRs (n = 40) to determine management. INTERVENTION: Patients in a prestress cohort managed nonoperatively versus patients in an LSR cohort managed operatively if stress positive (≥1 cm displacement on LSRs). MAIN OUTCOME MEASUREMENTS: Physical therapy clearance before discharge, discharge location, hospital length of stay, and inpatient opioid morphine milligram equivalents were measured. RESULTS: The prestress and LSR protocol groups were similar in demographic/injury characteristics (age, sex, mechanism, American Society of Anesthesiologists score, Nakatani classification, bilateral/unilateral injury, Denis zone, sacral fracture completeness, and sacral comminution). Forty-five percent of LSR protocol patients were stress-positive (n = 18) and managed operatively. The LSR protocol group was more likely to clear physical therapy by discharge (97.5% vs. 75.8%, PD: 21.7%, 95% CI: 5.1%-36.8%, P = 0.009), less likely to discharge to a rehabilitation facility (2.5% vs. 18.2%, PD: -15.7%, CI: -30.0% to -0.5%, P = 0.04), and had no difference in length of stay (MD: 0.0, CI:-1.0 to 1.0, P = 0.57) or inpatient opioid morphine milligram equivalents (MD: 9.0, CI: -60.0 to 101.0, P = 0.71). CONCLUSION: Implementation of an LSR protocol to determine management of minimally displaced stress-positive lateral compression type 1 injuries was associated with increased rates of operative management, physical therapy clearance by discharge, and a reduction in the number of patients discharging to rehabilitation facilities. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Combined Anterior-Posterior versus Posterior-Only Fixation of Stress-Positive Minimally Displaced Lateral Compression Type 1 (LC1) Pelvic Ring Injuries.

OBJECTIVES: To compare hospital outcomes and late displacement between stress-positive minimally displaced lateral compression type 1 (LC1) pelvic ring injuries treated with combined anterior-posterior versus posterior-only fixation. DESIGN: Retrospective comparative cohort. SETTING: Urban level-one trauma center. PATIENTS/PARTICIPANTS: LC1 injuries managed operatively. INTERVENTION: Anterior-posterior versus posterior-only fixation. MAIN OUTCOME MEASUREMENTS: Physical therapy (PT) clearance, discharge location, hospital length of stay (LOS), inpatient morphine equivalent doses (MED), and fracture displacement at follow-up. RESULTS: Groups were similar in demographic and injury characteristics (age, high energy mechanism, ASA score, stress displacement, and rami/sacral fracture classifications). Anterior-posterior fixation resulted in longer operative times (median difference (MD): 27.0 minutes, 95% confidence interval (CI): 17.0 to 40.0, P < 0.0001) and had a trend of increased estimated blood loss (MD: 10 mL, CI: 0 to 30, P = 0.07). Patients with anterior-posterior fixation required less inpatient MEDs (MD: -180.0, CI: -341.2 to -15.0, P = 0.02), were more likely to clear PT by discharge (100% vs. 70%, proportional difference (PD): 30%, CI: 2.0%-57.2%, P = 0.02), were less likely to discharge to rehabilitation facilities (0% vs. 30%, PD: 30%, CI: 2.0%-57.2%, P = 0.02), and had a trend of less days to clear PT after surgery (MD: -1, CI: -2 to 0, P = 0.09) and decreased LOS (MD: -1, CI: -4 to 1, P = 0.17). Late fracture displacement did not differ between groups. CONCLUSION: Anterior-posterior fixation of LC1 injuries was associated with an improved early hospital course-specifically, reduced inpatient opioid use and an increased number of patients who could clear PT and discharge home. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

A standardized method of measuring screw breach on postoperative computed tomography scans following percutaneous fixation of the posterior pelvic ring.

PURPOSE: To assess the reliability of a standardized measurement of screw breach on postoperative computed tomography (CT) scans following percutaneous fixation of the posterior pelvic ring. METHODS: Three orthopedic trauma surgeons independently utilized a standardized method of measuring posterior pelvic ring screw breaches on post-operative CT scan images. Breaches were measured as a continuous variable on sagittal images reformatted to be perpendicular to the screw on axial images. The inter-rater and intra-rater reliability of screw breach distance measurements was assessed. RESULTS: Measurements were performed on 42 screws in 20 patients. Screw types included S1-iliosacral (IS) (n = 16), S1-transsacral (TS) (n = 8), S2-IS (n = 2), and S2-TS (n = 16). Patients with varying degrees of screw breaches were chosen to test measurements across breach severities, including 0 mm (n = 10), ≤ 2 mm (n = 12), > 2 to 4 mm (n = 11), and > 4 mm (n = 9). The mean difference and 95% confidence interval (CI) between screw breach measurements between the three surgeons was - 0.13 mm (CI - 0.48 to 0.20), 0.05 mm (CI - 0.6 to 0.7), and 0.18 mm (CI - 0.47 to 0.85), respectively. The inter-rater reliability of the measurements was considered excellent (intraclass correlation coefficient (ICC), 0.93). The mean intra-rater reliability for the observers was considered good (ICC 88.5, CI 82 to 95). CONCLUSIONS: This simple standardized method of measuring screw breaches had excellent inter-rater reliability and would support comparisons of screw breach severity across studies. LEVEL OF EVIDENCE: Level III.

The lateral stress radiograph: an effective alternative to examination under anesthesia for identifying occult instability in minimally displaced lateral compression pelvic ring injuries.

PURPOSE: The purpose of this study was to review the practice of utilizing lateral stress radiographs (LSRs) to identify occult instability (≥ 10 mm of dynamic displacement on LSRs) of minimally displaced lateral compression type 1 (LC1) pelvic ring injuries and to evaluate for associations between instability and patient demographics, injury characteristics, and hospital course. METHODS: A retrospective review of a prospective registry from 2018 to 2022 identified 151 patients with LC1 injuries. LSRs were obtained in 86.8% (131/151) of patients. Three (2.2%) patients were excluded for malrotation of LSRs, leaving 128 patients for analysis. RESULTS: The median maximum dynamic displacement on LSRs was 12.2 mm (IQR: 5.9 to 17.3). Occult instability was present in 62.5% (80/128) of patients and was associated with older age (Median difference 11.0 years, 95% CI 3.0 to 20.0), Nakatani type 1 rami fractures (73.7% vs. 47.9%, p = 0.001), and rami fracture comminution (Proportional difference 58.7%, 95% CI 42.8 to 71.3%), but not gender, high-energy mechanism, bilateral rami fractures, Denis classification, sacral fracture completeness, or sacral comminution. Patients with occult instability took longer to ambulate 15 feet and clear physical therapy (PT), were more likely to be unable to clear PT by hospital day 3 or by time of discharge, had longer hospital stays, and were more likely to require rehabilitation facilities. CONCLUSION: LSRs were obtained in a majority of patients. Occult instability was frequently present and associated with older age, comminuted distal pubic rami fractures, longer hospital stays, longer times to mobilize and clear PT, and an increased need for rehabilitation facilities.

The effect of pelvic ring rotation and tilt on the radiographic teardrop distance: an important consideration in the assessment of dynamic displacement on stress radiographs.

PURPOSE: The purpose of this study was to determine the effect of rotation and tilt on the radiographic teardrop distance (TD) on anteroposterior (AP) pelvis radiographs. METHODS: Radiographic examination of a pelvis models was conducted utilizing increasing degrees of beam rotation and tilt on portable C-arm fluoroscopy. The TD, x-plane rotation (symphyseal-mid-sacrum distance (SMS)), and y-plane tilt (sacroiliac joint-symphysis distance (SIS)) were measured by four independent observers. Interobserver reliability was assessed using intraclass correlations. RESULTS: TD was altered by less than 2 mm with up to 7.5° fluoroscopic rotation (SMS: 3 cm) and up to 30° of inlet and 15° of outlet (SIS: ± 3.3 cm). SMS distance effectively corresponded to the degree of rotation present (r = 1.00, CI: 0.97 to 1.00, p < 0.0001) and was strongly correlated to TD (r = -0.95, CI: -0.99 to -0.67, p = 0.001). SIS distance effectively corresponded to the degree of tilt present (r = -0.97, CI: -0.99 to -0.88, p < 0.0001) and was correlated to TD (r = 0.94, CI: 0.75 to 0.99, p = 0.0001). Linear regression models determined that, with every degree of rotation and tilt, TD was altered by 0.4 mm and 0.09 mm, respectively (p = 0.0004, r2 = 0.93 and p < 0.0001, r2 = 0.94, respectively). Interobserver reliability among observers was excellent (0.92). CONCLUSION: The TD has excellent interobserver reliability and is minimally impacted by up to 7.5° of rotation, 30° inlet tilt, and 15° of outlet tilt. Utilization of these thresholds may ensure reliability of TD measurements when assessing pelvis stress radiographs.

Institution of same-day total joint replacement at an urban safety net hospital during the COVID-19 pandemic.

Background: Increasingly, total hip and total knee replacements are being performed at outpatient ambulatory surgery centers. The purpose of this study was to investigate the feasibility and safety of instituting a same-day surgery program for hip and knee replacement at an urban, safety net hospital. Methods: Retrospective review of a prospectively collected registry for all patients scheduled for same-day total joint replacement at a safety net hospital was performed. Medical records were reviewed for patient demographics, same-day hospital admissions, and 30-day emergency room/hospital admissions. Results: 131 same-day total joint replacements were identified, including 76 knees and 55 hips. Median ASA was 3, and median Charlson comorbidity score was 2. Rate of same-day surgery for total joint replacements increased from 4.5% in September 2020 to 100% in September 2021. On major patient outcomes, 3.8% of patients (n = 5) required conversion to inpatient admission. Rate of 30-Day Emergency Department (ED) visits was 13.0% (n = 17). Most common complaints included postoperative pain (n = 10), incision drainage/edema/hematoma (n = 9), and cellulitis (n = 2). 30-Day Hospital Readmissions occurred in 1.5% of patients (n = 2). Conclusion: Same-day hip and knee replacement can be performed safely at a safety net hospital. Unlike dedicated high-volume orthopedic hospitals or outpatient surgery centers, urban safety net hospitals face a different set of challenges and must care for a wide variety of patients who do not plan for their illness and/or may not be able to pay for their care. Outpatient total joint replacement may extend total joint replacement to patients who might not have access otherwise.

Three-Dimensional Computed Tomography Reconstructions Do Not Improve the Interobserver Reliability of the AO/Orthopaedic Trauma Association and Young and Burgess Pelvic Fracture Classifications.

Purpose: To evaluate the value of three-dimensional (3D) computed tomography (CT) scans on the interobserver and intraobserver reliability of AO/Orthopaedic Trauma Association (OTA) and Young and Burgess (YB) classifications for pelvic ring injuries. Methods: Seven reviewers (four fellowship-trained orthopaedic trauma surgeons and three fellows) independently classified 36 pelvic ring injuries using radiographs and axial two-dimensional (2D) CT scan images and then repeated this process 2 months later with the addition of 3D CT images. Interobserver and intraobserver reliability was assessed. Results: The interobserver reliability of the AO/OTA classification using 2D vs. 3D CT scans was considered fair (k 0.23, CI 0.17-0.29) vs. slight (k 0.16, CI 0.09-0.22), with no observed difference [mean difference (MD) - 0.07, CI 0.16-0.01]. The interobserver reliability of the YB classification using 2D vs. 3D CT scans was considered fair for both (k 0.37, CI 0.32-0.42, vs. 0.37, CI 0.30-0.45), with no observed difference (MD - 0.0005, CI - 0.08 to 0.08). The intraobserver reliability of the AO/OTA vs. YB classifications was considered fair (k 0.35, CI 0.26-0.44) vs. moderate (k 0.49, CI 0.40-0.57), with the YB classification having higher kappa value (MD 0.13, CI 0.01-0.26, p = 0.03). Conclusion: The addition of 3D CT scan reconstructions to radiographs and 2D CT did not improve the interobserver reliability of AO/OTA and YB classifications for pelvic ring injuries.

Rami Comminution Is Associated With Displacement of Minimally Displaced Lateral Compression Type 1 Injuries on Lateral Stress Radiographs.

OBJECTIVES: To determine whether displacement on lateral stress radiographs (LSRs) in patients with minimally displaced lateral compression type 1 pelvic ring injuries is associated with any demographic and/or injury characteristics. DESIGN: Retrospective comparative cohort. SETTING: Urban level 1 trauma center. PATIENTS/PARTICIPANTS: Ninety-three consecutive patients with minimally displaced lateral compression type 1 injuries. INTERVENTION: Displacement of pelvic ring injury on LSR (≥10 mm vs. <10 mm). MAIN OUTCOME MEASUREMENTS: Demographic and injury characteristics (mechanism of injury, Nakatani rami classification, rami comminution, Denis zone, complete/incomplete sacral fracture, sacral comminution). RESULTS: 65.6% of patients (n = 61) had ≥10 mm of displacement on LSR. On univariate analysis, displacement was associated with increased age [median difference 11: confidence interval (CI), 2-23], female sex [proportional difference (PD): 25.1%, CI, 3.9%-44.4%], Nakatani classification (type I PD: 27.9%, type II PD: -19.5%), and rami comminution (PD: 55.6%, CI, 35.4%-71.3%). On multivariate analysis, displacement was only associated with rami comminution (odds ratio: 16.48, CI, 4.67-58.17). Displacement was not associated with energy of injury mechanism, sacral fracture Denis zone, complete sacral fracture, sacral comminution, or bilateral rami fractures. CONCLUSIONS: Although rami comminution was the only variable found to be independently associated with displacement ≥10 mm on LSR, no single variable perfectly predicted displacement. Future studies are needed to determine whether displacement on stress radiographs should change the management of these injuries. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Defining Sacral Dysmorphism: What Size Corridor Precludes Transsacral Screw Placement.

OBJECTIVE: To determine what size S1-transsacral (TS) corridor is amenable to TS screw placement, as this is commonly used to identify sacral dysmorphism, and to determine if gender, ethnicity, or screw breach is associated with narrow corridors. DESIGN: Retrospective review. SETTING: Urban level-1 trauma center. PATIENTS: Two hundred ninety patients with pelvic ring injuries and preoperative computed tomography (CT) scans. INTERVENTION: Percutaneous posterior pelvic ring fixation. MAIN OUTCOME MEASUREMENTS: The width of the S1-TS corridor was measured on the axial (inlet) and coronal (outlet) reformatted CT images. Patients with S1-TS screw fixation and postoperative CT scans were identified. Corridor size, gender, ethnicity, and screw breach were documented. RESULTS: S1-TS screws were placed in 55 of the 290 patients. No S1-TS screws were placed in corridors less than 8 mm. Corridors of <8 mm were present in 114 (39%) of the 290 patients and were not associated with gender or ethnicity. S1-TS screws placed in small (<10 mm) versus large (≥10 mm) corridors did not have a detectable difference in screw breaches (5 of 8, 62% versus 19 of 47 40%; difference, 22%, 95% confidence interval -14% to 52%) or median (interquartile range) screw breach distance [3 mm (2.5-4.8) versus 3 mm (1.2-4.8); difference, 0.9 mm; confidence interval -1.6 to 2.2]. CONCLUSION: These data are useful for the standardization of sacral dysmorphism reporting based on corridor size. Screw breaches were common irrespective of TS corridor size, emphasizing the small degree of error allowed by this procedure. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Lateral Stress Radiographs of Lateral Compression Type 1 Pelvic Injuries, With the Injured Side Down or Up, Reliably Measure Occult Instability.

OBJECTIVES: To evaluate the interobserver reliability of measured displacement and occult instability of minimally displaced lateral compression type 1 (LC1) fractures on lateral stress radiographs (LSRs) and to compare differences in displacement between LSR with the injured side down (ID) and up (IU). DESIGN: Retrospective review. SETTING: Urban Level 1 trauma center. PATIENTS/PARTICIPANTS: Twenty-three adult patients with minimally displaced (<1 cm) LC1 injuries. INTERVENTION: None. MAIN OUTCOME MEASUREMENTS: Three orthopaedic surgeons measured the distance between the radiographic teardrops on LSR and supine anteroposterior pelvic radiographs to calculate dynamic fracture displacement. The interobserver reliability of the measured displacement, a continuous variable, was assessed by calculating the intraclass correlation coefficient. The interobserver reliability of occult instability (≥10 mm of displacement on LSR), a categorical variable, was assessed by calculating the kappa value. Matched-pairs analysis was performed to calculate the mean difference of measurements between observers and between ID and IU LSR. RESULTS: The interobserver reliability of the measured displacement was excellent (intraclass correlation coefficient 0.93). The mean difference in measurements between observers ranged from -1.8 to 0.96 mm. The mean difference in the measured displacement between ID and IU LSRs for each observer ranged from -0.6 to 0.3 mm. There was 83% (19/23 cases) agreement on the presence of occult instability (≥10 mm of displacement on LSR) on both ID and IU LSRs. The interobserver reliability of occult instability was moderate (kappa 0.76). CONCLUSIONS: Measured fracture displacement and occult instability of minimally displaced LC1 injuries were reliably measured and identified on LSR, regardless of the laterality.

Percutaneous Reduction of Intra-Articular Posterior Wall Acetabular Rim Fragment: Surgical Technique and Case Series With an Average Follow-Up of 2 Years.

SUMMARY: Small posterior wall rim fractures are typically stable; however, if incarcerated in the joint, they must be removed. It is possible to reduce the morbidity associated with open approaches by addressing these incarcerated fragments in a percutaneous manner. This allows the restoration of joint congruity and removal of the osteochondral fragment from the joint space. The following report details the surgical technique to accomplish this, and the results of a case series of patients who underwent this technique. The advantages include limiting the morbidity of an open approach. However, the surgeon must be prepared to convert to an open approach if percutaneous removal does not accomplish the goals of surgery-a concentric, stable hip joint.

The Antibiotic Cement Bead Rouleaux: A Technical Trick to Maximize the Surface Area to Volume Ratio of Cement Beads to Improve the Elution of Antibiotics.

SUMMARY: The use of antibiotic-impregnated cement as a local antibiotic delivery system is well-established as an adjunctive treatment for chronic osteomyelitis. Because the elution of antibiotics is a surface area phenomenon, the geometry of the cement is an important consideration. The antibiotic cement bead rouleaux technique is a simple and efficient method of bead fabrication that requires only 10 minutes of preparation time and readily available operating room supplies. The discoid structure of the beads provides 3 times the surface-area-to-volume ratio of a spherical bead, which facilitates antibiotic elution. Given the speed and ease of fabrication, along with optimized geometry, the antibiotic cement bead rouleaux is a useful addition to the surgeon's repertoire.