Dual-Energy CT and Cinematic Rendering to Improve Assessment of Pelvic Fracture Instability.

Background Grading of pelvic fracture instability is challenging in patients with pelvic binders. Dual-energy CT (DECT) and cinematic rendering can provide ancillary information regarding osteoligamentous integrity, but the utility of these tools remains unknown. Purpose To assess the added diagnostic value of DECT and cinematic rendering, with respect to single-energy CT (SECT), for discriminating any instability and translational instability in patients with pelvic binders. Materials and Methods In this retrospective analysis, consecutive adult patients (age ≥18 years) were stabilized with pelvic binders and scanned in dual-energy mode using a 128-section CT scanner at one level I trauma center between August 2016 and January 2019. Young-Burgess grading by orthopedists served as the reference standard. Two radiologists performed blinded consensus grading with the Young-Burgess system in three reading sessions (session 1, SECT; session 2, SECT plus DECT; session 3, SECT plus DECT and cinematic rendering). Lateral compression (LC) type 1 (LC-1) and anteroposterior compression (APC) type 1 (APC-1) injuries were considered stable; LC type 2 and APC type 2, rotationally unstable; and LC type 3, APC type 3, and vertical shear, translationally unstable. Diagnostic performance for any instability and translational instability was compared between reading sessions using the McNemar and DeLong tests. Radiologist agreement with the orthopedic reference standard was calculated with the weighted κ statistic. Results Fifty-four patients (mean age, 41 years ± 16 [SD]; 41 men) were analyzed. Diagnostic performance was greater with SECT plus DECT and cinematic rendering compared with SECT alone for any instability, with an area under the receiver operating characteristic curve (AUC) of 0.67 for SECT alone and 0.82 for SECT plus DECT and cinematic rendering (P = .04); for translational instability, the AUCs were 0.80 for SECT alone and 0.95 for SECT plus DECT and cinematic rendering (P = .01). For any instability, corresponding sensitivities were 61% (22 of 36 patients) for SECT alone and 86% (31 of 36 patients) for SECT plus DECT and cinematic rendering (P < .001). The corresponding specificities were 72% (13 of 18 patients) and 78% (14 of 18 patients), respectively (P > .99). Agreement (κ value) between radiologists and orthopedist reference standard improved from 0.44 to 0.76 for SECT versus the combination of SECT, DECT, and cinematic rendering. Conclusion Combined use of single-energy CT, dual-energy CT, and cinematic rendering improved instability assessment over that with single-energy CT alone. © RSNA, 2022 Online supplemental material is available for this article.

CT Prediction Model for Major Arterial Injury after Blunt Pelvic Ring Disruption.

Purpose To develop and test a computed tomography (CT)-based predictive model for major arterial injury after blunt pelvic ring disruptions that incorporates semiautomated pelvic hematoma volume quantification. Materials and Methods A multivariable logistic regression model was developed in patients with blunt pelvic ring disruptions who underwent arterial phase abdominopelvic CT before angiography from 2008 to 2013. Arterial injury at angiography requiring transarterial embolization (TAE) served as the outcome. Areas under the receiver operating characteristic (ROC) curve (AUCs) for the model and for two trauma radiologists were compared in a validation cohort of 36 patients from 2013 to 2015 by using the Hanley-McNeil method. Hematoma volume cutoffs for predicting the need for TAE and probability cutoffs for the secondary outcome of mortality not resulting from closed head injuries were determined by using ROC analysis. Correlation between hematoma volume and transfusion was assessed by using the Pearson coefficient. Results Independent predictor variables included hematoma volume, intravenous contrast material extravasation, atherosclerosis, rotational instability, and obturator ring fracture. In the validation cohort, the model (AUC, 0.78) had similar performance to reviewers (AUC, 0.69-0.72; P = .40-.80). A hematoma volume cutoff of 433 mL had a positive predictive value of 87%-100% for predicting major arterial injury requiring TAE. Hematoma volumes correlated with units of packed red blood cells transfused (r = 0.34-0.57; P = .0002-.0003). Predicted probabilities of 0.64 or less had a negative predictive value of 100% for excluding mortality not resulting from closed head injuries. Conclusion A logistic regression model incorporating semiautomated hematoma volume segmentation produced objective probability estimates of major arterial injury. Hematoma volumes correlated with 48-hour transfusion requirement, and low predicted probabilities excluded mortality from causes other than closed head injury. © RSNA, 2018 Online supplemental material is available for this article.

Quantitative MDCT assessment of binder effects after pelvic ring disruptions using segmented pelvic haematoma volumes and multiplanar caliper measurements.

OBJECTIVE: To assess effects of pelvic binders for different instability grades using quantitative multidetector computed tomography (MDCT) parameters including segmented pelvic haematoma volumes and multiplanar caliper measurements. METHODS: CT examinations of 49 patients with binders and 49 controls performed from January 2008-June 2016, and matched 1:1 for Tile instability grade and Pennal/Young-Burgess force vector, were compared for differences in pubic symphysis and sacroiliac displacement using caliper measurements in three orthogonal planes. Pelvic haematoma volumes (ml) were derived using semi-automated seeded region-growing segmentation. Median caliper measurements and volumes were compared using the Mann-Whitney U test, and correlations assessed with Pearson's correlation coefficient. Relevant caliper measurement cutoffs were established using ROC analysis. RESULTS: Rotationally unstable (Tile B) patients with binders showed significant decreases in sacroiliac diastasis (2.7 mm vs. 4.5 mm; p=0.003) and haematoma volumes (135 ml vs. 295 ml; p=0.008). Globally unstable (Tile C) binder patients showed decreased sacroiliac diastasis (4.7 mm vs. 6.4 mm, p=0.04), without significant difference in haematoma volumes (284 ml vs. 234 ml, p=0.34). Four Tile C patients with binders demonstrated over-reduction resulting in pubic body over-ride. CONCLUSION: Rotationally unstable patients with binders have significantly less sacroiliac diastasis versus controls, corresponding with significantly lower haematoma volumes. KEY POINTS: • Haematoma segmentation and multiplanar caliper measurements provide new insights into binder effects. • Binder reduction corresponds with decreased pelvic haematoma volume in rotationally unstable injuries. • Discrimination between rotational and global instability is important for management. • Several caliper measurement cut-offs discriminate between rotationally and globally unstable injuries. • Pubic symphysis over-ride is suggestive of binder over-reduction in globally unstable injuries.

Can MDCT Unmask Instability in Binder-Stabilized Pelvic Ring Disruptions?

OBJECTIVE: Pelvic binders may hinder radiologic assessment of pelvic instability after trauma, and avulsive injuries can potentially unmask instability in this setting. We compare the performance of MDCT for the detection of pelvic disruptions in patients with binders to a matched cohort without binders, and we assess the utility of avulsive injuries as signs of pelvic instability. MATERIALS AND METHODS: MDCT examinations of 56 patients with binders were compared with MDCT examinations of 54 patients without binders. Tile grading by an experienced orthopedic surgeon was used as the reference standard (A, stable; B, rotationally unstable; C, rotationally and vertically unstable). Two radiologists performed blinded reviews of CT studies in two reading sessions (sessions 1 and 2). In session 1, Tile grade was predicted on the basis of established signs of instability, including pubic symphysis and sacroiliac (SI) joint widening. In session 2, readers could change the Tile grade when avulsive injuries were seen. Diagnostic performance for predicting rotational instability and vertical instability was assessed. RESULTS: In the binder group, AUCs under the ROC curves for rotational instability increased from fair (0.73-0.77) to good (0.82-0.89) when avulsive signs were considered. In the control group, AUCs were good in both sessions. AUCs for vertical instability were fair with binders in both sessions. Agreement with the reference standard increased from fair (0.30-0.32) to moderate (0.46-0.54) when avulsive signs were considered in the binder group but were in the moderate range for both sessions in the control group. Combined evaluation for inferolateral sacral fractures, ischial spine fractures, and rectus abdominis avulsions resulted in optimal discrimination of rotational instability. CONCLUSION: Evaluation for avulsive signs improves MDCT sensitivity for the detection of rotational instability but not vertical instability in patients with binders.

Will My Tibial Fracture Heal? Predicting Nonunion at the Time of Definitive Fixation Based on Commonly Available Variables.

BACKGROUND: Accurate prediction of tibial nonunions has eluded researchers. Reliably predicting tibial nonunions at the time of fixation could change management strategies and stimulate further research. QUESTIONS/PURPOSES: We asked (1) whether data from medical records, fracture characteristics, and radiographs obtained at the time of fixation would identify features predictive of tibial fracture nonunion; and (2) whether this information could be used to create a model to assess the chance of nonunion at the time of intramedullary (IM) nail fixation of the tibia. METHODS: We retrospectively reviewed all tibial shaft fractures treated at our center from 2007 to 2014. We conducted a literature review and collected data on 35 factors theorized to contribute to delayed bone healing. Patients were followed to fracture healing or surgery for nonunion. Patients with planned prophylactic nonunion surgery were excluded because their nonunions were anticipated and our focus was on unanticipated nonunions. Our cohort consisted of 382 patients treated with IM nails for tibial shaft fractures (nonunion, 56; healed, 326). Bivariate and multivariate regression techniques and stepwise modeling approaches examined the relationship between variables available at definitive fixation. Factors were included in our model if they were identified as having a modest to large effect size (odds ratio > 2) at the p < 0.05 level. RESULTS: A multiple variable logistic regression model was developed, including seven factors (p < 0.05; odds ratio > 2.0). With these factors, we created the Nonunion Risk Determination (NURD) score. The NURD score assigns 5 points for flaps, 4 points for compartment syndrome, 3 points for chronic condition(s), 2 points for open fractures, 1 point for male gender, and 1 point per grade of American Society of Anesthesiologists Physical Status and percent cortical contact. One point each is subtracted for spiral fractures and for low-energy injuries, which were found to be predictive of union. A NURD score of 0 to 5 had a 2% chance of nonunion; 6 to 8, 22%; 9 to 11, 42%; and > 12, 61%. CONCLUSIONS: The proposed nonunion prediction model (NURDS) seems to have potential to allow clinicians to better determine which patients have a higher risk of nonunion. Future work should be directed at prospectively validating and enhancing this model. LEVEL OF EVIDENCE: Level III, diagnostic study.

Work Productivity Loss After Minimally Displaced Complete Lateral Compression Pelvis Fractures.

OBJECTIVE: To quantify work impairment and economic losses due to lost employment, lost work time (absenteeism), and lost productivity while working (presenteeism) after a lateral compression pelvic ring fracture. Secondarily, productivity loss of patients treated with surgical fixation versus nonoperative management was compared. DESIGN: Secondary analysis of a prospective, multicenter trial. SETTING: Two level I academic trauma centers. PATIENT SELECTION CRITERIA: Adult patients with a lateral compression pelvic fracture (OTA/AO 61-B1/B2) with a complete posterior pelvic ring fracture and less than 10 mm of initial displacement. Excluded were patients who were not working or non-ambulatory before their pelvis fracture or who had a concomitant spinal cord injury. OUTCOME MEASURES AND COMPARISONS: Work impairment, including hours lost to unemployment, absenteeism, and presenteeism, measured by Work Productivity and Activity Impairment assessments in the year after injury. Results after non-operative and operative treatment were compared. RESULTS: Of the 64 included patients, forty-seven percent (30/64) were treated with surgical fixation, and 53% (30/64) with nonoperative management. 63% returned to work within 1 year of injury. Workers lost an average of 67% of a 2080-hour average work year, corresponding with $56,276 in lost economic productivity. Of the 1395 total hours lost, 87% was due to unemployment, 3% to absenteeism, and 10% to presenteeism. Surgical fixation was associated with 27% fewer lost hours (1155 vs. 1583, P = 0.005) and prevented $17,266 in average lost economic productivity per patient compared with nonoperative management. CONCLUSIONS: Lateral compression pelvic fractures are associated with a substantial economic impact on patients and society. Surgical fixation reduces work impairment and the corresponding economic burden. LEVEL OF EVIDENCE: Economic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Small-Fragment Plate Fixation of Humeral Shaft Fractures.

Fixation of humeral shaft fractures is frequently performed with large-fragment (4.5 mm) plates to accommodate immediate weight bearing. Use of small-fragment (3.5 mm) plates as an alternative carries theoretical benefits. We examined nonunion rates and postoperative radial nerve palsy (RNP) rates in a retrospective cohort of patients undergoing open reduction and internal fixation of humeral shaft fractures with 3.5-mm or 4.5-mm plates. Two hundred thirty-six patients with 241 humeral shaft fractures were included. Small 3.5-mm plates were used in 83% of the patients, and large 4.5-mm plates were used in 17% of the patients. Fifty-three percent were made weight bearing as tolerated following surgical fixation. There was a 7% incidence of nonunion and a 10% incidence of RNP in the 3.5-mm plate group. There was a 7% incidence of nonunion and a 15% incidence of RNP in the 4.5-mm plate group. No statistically significant relationship was shown between nonunion or RNP and plate size (P=.74 and P=.39). No relationship was shown between nonunion and postoperative weight-bearing status (P=.45). Subgroup analysis according to plate size additionally showed no association of nonunion with postoperative weight bearing in both the 4.5-mm (P=.55) and the 3.5-mm (P=.25) cohorts. Small-fragment and large-fragment plating of humeral shaft fractures resulted in comparable union and RNP rates, regardless of postoperative weight-bearing status. Our findings suggest that 3.5-mm plate fixation of humeral shaft fractures is a safe alternative to 4.5-mm plate fixation. [Orthopedics. 2023;46(4):198-204.].

A deep surgical site infection risk score for patients with open tibial shaft fractures treated with intramedullary nail.

OBJECTIVES: To identify deep infection risk factors in patients with open tibial shaft fractures and to develop a scoring algorithm to predict the baseline deep infection risk in this patient population. METHODS: A retrospective cohort study conducted at a single academic trauma center identified patients with open tibial shaft fractures treated with intramedullary nail fixation from December 2006 to October 2020. The primary outcome was a deep surgical site infection requiring surgical debridement. The outcome was identified by Current Procedural Terminology codes and confirmed with a medical chart review documenting evidence of a tibial draining wound or sinus tract. RESULTS: Deep surgical site infection occurred in 13% of patients (97/769). Factors that predicted deep surgical site infection were identified. Gustilo-Anderson type IIIB or IIIC was the strongest predictor with a 12-fold increase in the odds of deep infection (OR 11.8, p < 0.001). Additional factors included age >40 years (OR 1.7, p = 0.03), American Society of Anesthesiologists score ≥3 (OR 1.9, p < 0.01), Gustilo-Anderson type IIIA vs. type I or II (OR 2.8, p = 0.004), and gunshot wounds (OR 2.9, p = 0.02). The risk scoring model predicted patients who would develop an infection with an acceptable level of accuracy (AUC 0.79). The risk score categorized patients from a low probability of deep infection 2%-6% with <10 points to high risk (58%-69%) with >40 points. CONCLUSIONS: This risk score model predicts deep postoperative infection in patients with open tibial shaft fractures treated with intramedullary nails. The ability to accurately estimate deep infection risk at the time of presentation might aid patient expectation management and allow clinicians to focus infection prevention strategies on the high-risk subset of this population.

The Effect of Surgeon Experience on Short- to Medium-Term Complication Rate Following Operative Fixation of Acetabular Fractures.

OBJECTIVES: Operative management of acetabular fractures is technically challenging, but there is little data regarding how surgeon experience affects outcomes. Previous efforts have focused only on reduction quality in a single surgeon series. We hypothesized that increasing surgeon experience would be associated with improved acetabular surgical outcomes in general. DESIGN: Retrospective cohort study. SETTING: Urban academic level-I trauma center. PATIENTS/PARTICIPANTS: Seven hundred ninety-five patients who underwent an open reduction internal fixation for an acetabular fracture. RESULTS: There was a significant association between surgeon experience and certain outcomes, specifically reoperation rate (16.9% overall), readmission rate (13.9% overall), and reduction quality. Deep infection rate (9.7% overall) and secondary displacement rate (3.7% overall) were not found to have a significant association with surgeon experience. For reoperation rate, the time until 50% peak performance was 2.4 years in practice. CONCLUSION: Surgeon experience had a significant association with reoperation rate, quality of reduction, and readmission rate after open reduction internal fixation of acetabular fractures. Other patient outcomes were not found to be associated with surgeon experience. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Open reduction and internal fixation alone versus open reduction and internal fixation plus total hip arthroplasty for displaced acetabular fractures in patients older than 60 years: A prospective clinical trial.

INTRODUCTION: The optimal treatment of elderly patients with an acetabular fracture is unknown. We conducted a prospective clinical trial to compare functional outcomes and reoperation rates in patients older than 60 years with acetabular fracture treated with open reduction and internal fixation (ORIF) alone versus ORIF plus concomitant total hip arthroplasty (ORIF + THA). Our hypothesis was that patients who had ORIF + THA would have better patient reported outcomes and lower reoperation rates postoperatively. METHODS: Inclusion criteria were patients older than 60 years with acetabular fracture plus at least one of three fracture characteristics: dome impaction, femoral head fracture, or posterior wall component. Eligible patients were operative candidates based on fracture displacement, ambulatory status, and physiological appropriateness. Patients received either ORIF alone or ORIF + THA (accomplished at same surgery through same incision). Outcome measurements included Western Ontario and McMaster Universities Osteoarthritis Index hip score, Short Form 36, Harris Hip Score, and Patient Satisfaction Questionnaire Short Form scores. Additionally, patients were monitored for any unplanned reoperation within 2 years. RESULTS: Forty-seven of 165 eligible patients with an average age of 70.7 years were included. The mean Harris Hip Score difference favored ORIF + THA (mean difference, 12.3, [95% confidence interval (CI), -0.3 to 24.9, p = 0.07]). No clinically important differences were detected in any other validated outcome score or patient satisfaction score 1 year after surgery. ORIF + THA decreased the absolute risk of reoperation by 28% (95% CI, 13% to 44%, p < 0.01). No postoperative hip dislocation occurred in either group. CONCLUSIONS: In patients older than 60 years with an operative displaced acetabular fracture with specific fracture features (dome impaction, femoral head fracture, or posterior wall component), treatment with ORIF + THA resulted in fewer reoperations than treatment with ORIF alone. No differences in patient satisfaction and other validated outcome measures were detected.

Fixed angle device comparison in young femoral neck fractures: Dynamic hip screw vs dynamic helical hip system.

INTRODUCTION: Femoral neck fractures in the young patient present a unique challenge. Most surgeons managing these injuries prefer a fixed angle implant, however these devices are fraught with problems. A dynamic hip screw (DHS) is one such fixed angle device that risks malreduction through rotational torque during screw insertion. To avoid this risk some surgeons utilize a dynamic helical hip system (DHHS), however little is known about the complication profile of this device. We hypothesized that the complication rate between these two devices would be similar. PATIENTS AND METHODS: All patients presenting to a single tertiary referral center with a femoral neck fracture were identified from a prospectively collected trauma database over an 11-year period. Patients were included if they were less than 60 years of age, treated with a DHS or DHHS, and had at least 6 months of follow-up. Demographic data, injury characteristics, and post-operative complications were obtained through chart review. Standard statistical comparisons were made between groups. A total of 77 patients met inclusion criteria. RESULTS: Average age of patients was 38 years (range: 18-59) and 56 (73%) were male. The DHS was used in 37 (48%) patients and the DHHS was used in 40 (52%) patients. Demographic data including average age, gender, body mass index, and smoking status did not differ between the groups. There were 29 (39%) total complications of interest (femoral neck shortening >5 mm, non-union requiring osteotomy, conversion to THA, and osteonecrosis. There were 19 (51%) complications in the DHS group and 10 (25%) in the DHHS group (p = 0.01, risk difference 25%, 95% CI 7-43). Comparisons of the individual complications about the DHS and DHHS cohort did not reach statistical significance for non-union (8% vs 3%) or THA (16% vs 13%) (p = 0.33, p = 0.64, respectively) but a difference was detected in the rate of shortening (27% vs 10%; p = 0.05). CONCLUSION: This study demonstrates a high risk of complication when managing young femoral neck fractures in line with prior literature. The major complication rate of non-union requiring osteotomy or fixation failure resulting in THA was no different between the two groups, but the rate of shortening was greater the DHS group. This data suggests the DHHS may be a suitable device to manage the young femoral neck fracture and without increased risk of complication.

The impact of COVID-19 restrictions on participant enrollment in the PREPARE trial.

Background: At the initiation of the COVID-19 pandemic, restrictions forced researchers to decide whether to continue their ongoing clinical trials. The PREPARE (Pragmatic Randomized Trial Evaluating Pre-Operative Alcohol Skin Solutions in Fractured Extremities) trial is a pragmatic cluster-randomized crossover trial in patients with open and closed fractures. PREPARE was enrolling over 200 participants per month at the initiation of the pandemic. We aim to describe how the COVID-19 research restrictions affected participant enrollment. Methods: The PREPARE protocol permitted telephone consent, however, sites were obtaining consent in-person. To continue enrollment after the initiation of the restrictions participating sites obtained ethics approval for telephone consent scripts and the waiver of a signature on the consent form. We recorded the number of sites that switched to telephone consent, paused enrollment, and the length of the pause. We used t-tests to compare the differences in monthly enrollment between July 2019 and November 2020. Results: All 19 sites quickly implement telephone consent. Fourteen out of nineteen (73.6%) sites paused enrollment due to COVID-19 restrictions. The median length of enrollment pause was 46.5 days (range, 7-121 days; interquartile range, 61 days). The months immediately following the implementation of restrictions had significantly lower enrollment. Conclusion: A pragmatic design allowed sites to quickly adapt their procedures for obtaining informed consent via telephone and allowed for minimal interruptions to enrollment during the pandemic.

Medial sided articular impaction in tibial plateau fractures.

INTRODUCTION: Tibial plateau fractures are a heterogenous group of injuries with a variable amount of articular injury and are commonly associated with lateral sided articular impaction. Previous work has focused on describing the morphology of tibial plateau fractures, but has neglected description of medial sided articular impaction. The aim of this investigation was to assess the morphology of medial sided articular impaction in tibial plateau fractures, with specific attention directed toward the frequency, location, size, and associated fracture patterns. METHODS: Skeletally mature patients presenting to a Level I trauma center from 2008-2018 with a tibial plateau fracture (AO/OTA 41B-C) were identified retrospectively. Fractures were classified by AO/OTA and Schatzker type. Radiographs and computed tomography (CT) scans were reviewed to identify and localize medial sided articular impaction. The location and surface area of impaction was characterized by creating frequency diagram heat maps from axial CT scans. Descriptive statistics were performed using standard measures. RESULTS: Of the 1032 tibial plateau fractures included, 82 (7.9%) were noted to have medial sided articular impaction. Rate of impaction varied by fracture type (p = 0.03): Schatzker II, 2% (7 of 381); Schatzker IV, 21% (19 of 96); and Schatzker VI, 11% (56 of 524). Average total surface area of impaction was 9% of the total and 19% of the medial plateau area. Area of impaction varied by fracture type (p = 0.004): Schatzker II, 6% (95% confidence interval [CI], 4%-7%); Schatzker IV, 11% (95% CI, 9%-13%), and Schatzker VI, 9% (95% CI, 7%-11%). The area of impaction occurred primarily along the lateral aspect of the medial plateau in Schatzker II fractures, in the anteromedial quadrant of Schatzker IV fractures, and was evenly distributed across the medial plateau in Schatzker VI fractures. CONCLUSIONS: Surgeons should be aware that medial articular impaction is present in approximately 8% of tibial plateau fractures. Schatzker IV fractures are most likely to have medial impaction and a larger proportion of the joint surface involved in these injuries.

Analysis of Computed Tomography-Based Technique for Measuring Femoral Anteversion: Implications for Measuring Rotation After Femoral Intramedullary Nail Insertion.

OBJECTIVES: To assess the reliability of the current computed tomography (CT)-based technique for determining femoral anteversion and quantify the prevalence and magnitude of side-to-side differences. DESIGN: Cross-sectional cohort study. SETTING: Academic trauma center. PATIENTS: We reviewed CT scans from 120 patients with bilateral full-length axial cuts of both femurs. Two hundred forty femurs with no fractures or other identifying features in their femora were included. Ten unique data sets were created to measure anteversion of the left and right sides. MAIN OUTCOME MEASUREMENTS: Intraobserver and interobserver reliability were calculated using intraclass correlation coefficients (ICCs) and pooled absolute differences. The mean absolute difference between the sides was determined using a fixed-effects model. RESULTS: Interobserver reliability was high (ICC: 0.85, 95% confidence interval [CI]: 0.83-0.88). The pooled mean absolute magnitude of variation between reviewers was small at 1.6 degrees (95% CI: 1.4-1.8 degrees) per scan. The intraobserver reproducibility was high (ICC: 0.91, 95% CI: 0.88-0.93) with a mean error of 2.7 degrees (95% CI: 2.2-3.1 degrees) per repeat viewing of the same scan by the same person. The magnitude of side-to-side variation was 2.0 degrees (95% CI: 1.5-2.6 degrees). Twenty-one subjects (18%, 95% CI: 12%-25%) had a mean side-to-side calculated femoral anteversion difference of ≥10 degrees, whereas 6 (5%, 95% CI: 2-10) subjects had a calculated mean side-to-side difference of ≥15 degrees. CONCLUSIONS: CT based femoral anteversion measurement techniques demonstrate good precision. Only 1 in 20 patients had side-to-side differences of 15 degrees or more.

Do Fully Threaded Transiliac-Transsacral Screws Improve Mechanical Stability of Vertically Unstable Pelvic Fractures? A Cadaveric Biomechanical Analysis.

OBJECTIVE: To determine whether fully threaded transiliac-transsacral (TI-TS) fixation is biomechanically superior to partially threaded TI-TS fixation of vertically unstable transforaminal sacral fractures. METHODS: Vertically unstable zone 2 sacral fractures were created in 20 human cadaveric pelves with a unilateral osteotomy and resection of 1 cm of bone through the foramen of the sacrum to represent comminution. Ten specimens received either 2 7.3-mm fully threaded or 2 7.3-mm partially threaded TI-TS screw fixation at the S1 and S2 body, and every specimen received standard 3.5-mm 8-hole parasymphyseal plating anteriorly. Each pelvis was loaded to 250 N at 3 Hz for 100,000 cycles and then loaded to failure. The primary outcome was fracture displacement at the S1 foramen, which was measured at 25,000, 50,000, 75,000, and 100,000 cycles. Secondary outcomes were simulated clinical failure of ≥1 cm displacement at the S1 foramen to determine occurrence probability of failure, and load at failure was defined as 2.5 cm of the linear loading system displacement. Specimens in the fully threaded and partially threaded cohorts were otherwise respectively comparable in regards to age, gender, and bone density. RESULTS: Five of the 10 TI-TS partially threaded specimens experienced simulated clinical failure with >1 cm displacement at the S1 foramen compared with 0 of the 10 TI-TS fully threaded cohort (50% vs. 0%, P = 0.03). The mean maximal displacement at the S1 foramen was greater in the partially threaded cohort (9.3 mm) compared with the fully threaded cohort (3.6 mm; P = 0.004). Fully threaded specimens also demonstrated greater mean force to failure than the partially threaded specimens (461 N vs. 288 N; P = 0.0001). CONCLUSIONS: Fully threaded TI-TS screw fixation seems to be mechanically superior to partially threaded fixation in a cadaveric vertically unstable transforaminal sacral fracture model with significantly less displacement of the posterior pelvic ring and greater load to failure.

Association Between Femoral "Spike" Size After Intramedullary Nailing and Subsequent Knee Motion Surgery.

OBJECTIVES: To determine the association between displaced femoral shaft bone fragments ("spikes") seen on radiographs after intramedullary nail insertion and the need for future motion surgery. DESIGN: Retrospective case-control study. SETTING: Academic trauma center. PATIENTS: We included patients with femoral shaft fractures treated with intramedullary nail insertion. Case patients (n = 22) had developed knee stiffness treated with motion surgery. The control group was a randomly selected sample (1:3 ratio). MAIN OUTCOME MEASURES: Motion surgery to address knee stiffness. We defined a "spike distance ratio" and "spike area ratio" from initial postoperative anteroposterior and lateral radiographs. Multivariable logistic regression determined the effect of spike distance and area ratios on the likelihood of need for motion surgery, controlling for polytraumatic injuries and bilateral fractures. RESULTS: The case group had a median femoral spike distance ratio of 1.9 [interquartile range (IQR), 1.6-2.5] compared with 1.5 (IQR, 1.2-1.8) in the control group. An increased femoral spike distance ratio was associated with increased odds of motion surgery (P < 0.01). A femoral spike distance >2 times the femoral radius had 32 times the odds (95% confidence interval, 2-752) of motion surgery compared with patients with distance ratios <1.25. Median femoral spike area ratios were similar between the case (0.2; IQR, 0.1-0.5) and control (0.2; IQR, 0.0-0.5) groups and were not associated with increased odds of motion surgery (P = 0.34). CONCLUSIONS: A larger spike distance ratio is associated with increased odds of subsequent motion surgery. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Assessing Soft Tissue Perfusion Using Laser-Assisted Angiography in Tibial Plateau and Pilon Fractures: A Pilot Study.

OBJECTIVES: To determine whether skin perfusion surrounding tibial plateau and pilon fractures is associated with the Tscherne classification for severity of soft tissue injury. The secondary aim was to determine if soft tissue perfusion improves from the time of injury to the time of definitive fracture fixation in fractures treated using a staged protocol. DESIGN: Prospective cohort study. SETTING: Academic trauma center. PATIENTS: Eight pilon fracture patients and 19 tibial plateau fracture patients who underwent open reduction internal fixation. MAIN OUTCOME MEASURES: Skin perfusion (fluorescence units) as measured by LA-ICGA. RESULTS: Six patients were classified as Tscherne grade 0, 9 as grade 1, 10 as grade 2, and 2 as grade 3. Perfusion decreased by 14 fluorescence units (95% confidence interval, -21 to -6; P < 0.01) with each increase in Tscherne grade. Sixteen patients underwent staged fixation with an external fixator (mean time to definitive fixation 14.1 days). The mean perfusion increased significantly at the time of definitive fixation by a mean of 13.9 fluorescence units (95% confidence interval 4.8-22.9; P = 0.01). CONCLUSIONS: LA-ICGA perfusion measures are associated with severity of soft tissue injury surrounding orthopaedic trauma fractures and appear to improve over time when fractures are stabilized in an external fixator. Further research is warranted to investigate whether objective perfusion measures are predictive of postoperative wound healing complications and whether this tool can be used to effectively guide timing of safe surgical fixation. LEVEL OF EVIDENCE: Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

A Prospective Clinical Trial Comparing Surgical Fixation Versus Nonoperative Management of Minimally Displaced Complete Lateral Compression Pelvis Fractures.

OBJECTIVE: To compare the early pain and functional outcomes of operative fixation versus nonoperative management for minimally displaced complete lateral compression (LC; OTA/AO 61-B1/B2) pelvic fractures. DESIGN: Prospective clinical trial. SETTING: Two academic trauma centers. PATIENTS: Forty-eight adult patients with LC pelvic ring injuries with <10 mm of displacement were treated nonoperatively and 47 with surgical fixation. Sixty percent of participants were randomized. Seventy-three percent of the fractures were displaced <5 mm, and 71% were LC-1 patterns. INTERVENTION: Operative fixation versus nonoperative management. MAIN OUTCOME MEASUREMENTS: The primary outcome was patient-reported pain using the 10-point Brief Pain Inventory. Functional outcome was measured using the Majeed pelvic score. Outcomes were analyzed using hierarchical Bayesian models to compare the average treatment effect from injury to 12 and 52 weeks postinjury. The probability of the mean treatment benefit exceeding a clinically important difference was determined. RESULTS: The 3-month average treatment effect of surgery compared with nonoperative management was a 1.2-point reduction in pain [95% credible interval (CrI): 0.4-1.9] and an 8% absolute improvement in the Majeed score (95% CrI: 3%-14%). Similar results persisted to 1 year. Patients with initial fracture displacement ≥5 mm experienced a larger reduction in pain (2.2, 95% CrI: 0.9-3.5) compared with those patients with less initial displacement (0.9, 95% CrI: 0.1-1.8). CONCLUSION: On average, surgical fixation likely provides a small improvement in pain and functional outcome for up to 12 months. Patients with ≥5 mm of posterior pelvic ring displacement are more likely to experience clinically important improvements in pain. LEVEL OF EVIDENCE: Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

Implementing stakeholder engagement to explore alternative models of consent: An example from the PREP-IT trials.

INTRODUCTION: Cluster randomized crossover trials are often faced with a dilemma when selecting an optimal model of consent, as the traditional model of obtaining informed consent from participant's before initiating any trial related activities may not be suitable. We describe our experience of engaging patient advisors to identify an optimal model of consent for the PREP-IT trials. This paper also examines surrogate measures of success for the selected model of consent. METHODS: The PREP-IT program consists of two multi-center cluster randomized crossover trials that engaged patient advisors to determine an optimal model of consent. Patient advisors and stakeholders met regularly and reached consensus on decisions related to the trial design including the model for consent. Patient advisors provided valuable insight on how key decisions on trial design and conduct would be received by participants and the impact these decisions will have. RESULTS: Patient advisors, together with stakeholders, reviewed the pros and cons and the requirements for the traditional model of consent, deferred consent, and waiver of consent. Collectively, they agreed upon a deferred consent model, in which patients may be approached for consent after their fracture surgery and prior to data collection. The consent rate in PREP-IT is 80.7%, and 0.67% of participants have withdrawn consent for participation. DISCUSSION: Involvement of patient advisors in the development of an optimal model of consent has been successful. Engagement of patient advisors is recommended for other large trials where the traditional model of consent may not be optimal.