Parkland Trauma Index of Mortality: Real-Time Predictive Model for Trauma Patients.

OBJECTIVE: Vital signs and laboratory values are used to guide decisions to use damage control techniques in lieu of early definitive fracture fixation. Previous models attempted to predict mortality risk but have limited utility. There is a need for a dynamic model that captures evolving physiologic changes during a trauma patient's hospital course. METHODS: The Parkland Trauma Index of Mortality (PTIM) is a machine learning algorithm that uses electronic medical record data to predict mortality within 48 hours during the first 3 days of hospitalization. It updates every hour, recalculating as physiology changes. The model was developed using 1935 trauma patient encounters from 2009 to 2014 and validated on 516 patient encounters from 2015 to 2016. Model performance was evaluated statistically. Data were collected retrospectively on its performance after 1 year of clinical use. RESULTS: In the validation data set, PTIM accurately predicted 52 of the sixty-three 12-hour time intervals within 48 hours of mortality, for sensitivity of 82.5% [95% confidence interval (CI), 73.1%-91.9%]. The specificity was 93.6% (95% CI, 92.5%-94.8%), and the positive predictive value (PPV) was 32.5% (95% CI, 25.2%-39.7%). PTIM predicted survival for 1608 time intervals and was incorrect only 11 times, yielding a negative predictive value of 99.3% (95% CI, 98.9%-99.7%). The area under the curve of the receiver operating characteristic curve was 0.94.During the first year of clinical use, when used in 776 patients, the last PTIM score accurately predicted 20 of the twenty-three 12-hour time intervals within 48 hours of mortality, for sensitivity of 86.9% (95% CI, 73%-100%). The specificity was 94.7% (95% CI, 93%-96%), and the positive predictive value was 33.3% (95% CI, 21.4%-45%). The model predicted survival for 716 time intervals and was incorrect 3 times, yielding a negative predictive value of 99.6% (95% CI, 99.1%-100%). The area under the curve of the receiver operating characteristic curve was 0.97. CONCLUSIONS: By adapting with the patient's physiologic response to trauma and relying on electronic medical record data alone, the PTIM overcomes many of the limitations of previous models. It may help inform decision-making for trauma patients early in their hospitalization. LEVEL OF EVIDENCE: Prognostic Level I. See Instructions for Authors for a complete description of levels of evidence.

One-stage revision is as effective as two-stage revision for chronic culture-negative periprosthetic joint infection after total hip and knee arthroplasty.

AIMS: Removal of infected components and culture-directed antibiotics are important for the successful treatment of chronic periprosthetic joint infection (PJI). However, as many as 27% of chronic PJI patients yield negative culture results. Although culture negativity has been thought of as a contraindication to one-stage revision, data supporting this assertion are limited. The aim of our study was to report on the clinical outcomes for one-stage and two-stage exchange arthroplasty performed in patients with chronic culture-negative PJI. METHODS: A total of 105 consecutive patients who underwent revision arthroplasty for chronic culture-negative PJI were retrospectively evaluated. One-stage revision arthroplasty was performed in 30 patients, while 75 patients underwent two-stage exchange, with a minimum of one year's follow-up. Reinfection, re-revision for septic and aseptic reasons, amputation, readmission, mortality, and length of stay were compared between the two treatment strategies. RESULTS: The patient demographic characteristics did not differ significantly between the groups. At a mean follow-up of 4.2 years, the treatment failure for reinfection for one-stage and two-stage revision was five (16.7%) and 15 patients (20.0%) (p = 0.691), and for septic re-revision was four (13.3%) and 11 patients (14.7%) (p = 0.863), respectively. No significant differences were observed between one-stage and two-stage revision for 30- 60- and 90-day readmissions (10.0% vs 8.0%; p = 0.714; 16.7% vs 9.3%; p = 0.325; and 26.7% vs 10.7%; p = 0.074), one-year mortality (3.3% vs 4.0%; p > 0.999), and amputation (3.3% vs 1.3%; p = 0.496). CONCLUSION: In this non-randomized study, one-stage revision arthroplasty demonstrated similar outcomes including reinfection, re-revision, and readmission rates for the treatment of chronic culture-negative PJI after TKA and THA compared to two-stage revision. This suggests culture negativity may not be a contraindication to one-stage revision arthroplasty for chronic culture-negative PJI in selected patients. Cite this article: Bone Joint J 2021;103-B(3):515-521.

Outcome of Debridement, Antibiotics, and Implant Retention With Modular Component Exchange in Acute Culture-Negative Periprosthetic Joint Infections.

BACKGROUND: Modular component exchange and culture-directed antibiotic treatment is routinely employed for acute periprosthetic joint infection (PJI). However, as many as 7%-23% of PJIs have been reported to yield negative culture results. The efficacy of debridement, antibiotics, and implant retention (DAIR) with modular component exchange in the setting of acute culture negative PJI remains largely unknown. The aim of our study is to evaluate the outcomes of DAIR with modular component exchange in acute culture-positive and culture-negative PJI. METHODS: A total of 149 consecutive patients with primary total joint replacements (90 total knee arthroplasties and 59 total hip arthroplasties) who underwent DAIR with modular component exchange for acute PJI with at least 3 years of follow-up were evaluated: (1) 46 culture-negative PJI patients and (2) 103 culture-positive PJI patients. Reinfection and aseptic revision rates along with complication rates were compared. RESULTS: The reinfection rate for DAIR in acute culture-negative PJI was 13.0% compared to 19.4% in culture-positive PJI (P = .48). Mean survival time from reinfection between culture-negative (7.7 ± 0.4 years) and culture-positive (7.4 ± 0.3 years) PJI groups did not differ significantly (P = .40). Aseptic revision rates were 8.7% and 4.9% (P = .46), respectively, with loosening being the primary reason for implant failure in both cohorts. CONCLUSIONS: Despite lack of an identifying organism to guide postoperative antibiotic therapy, DAIR with modular component exchange for acute culture-negative PJI was associated with similar reinfection rates compared to acute culture-positive PJI, suggesting that culture negativity may not be a contraindication to DAIR in patients with acute PJI.

The effect of age on risk of retear after rotator cuff repair: a systematic review and meta-analysis.

HYPOTHESIS: The purpose of this study was to perform a systematic review and meta-analysis to determine the effect of age on rotator cuff repair failure. The hypothesis of this study was that increased patient age would lead to a higher rate of retears and/or repair failures after rotator cuff repair. METHODS: We conducted a systematic review and meta-analysis of level I and II studies evaluating patients undergoing rotator cuff repair that also included an imaging assessment of the structural integrity of the repair. Univariate and multivariate meta-regression was performed to assess the dependence of the retear rate on the mean age of the cohort, imaging modality, time to imaging, and publication year. RESULTS: The meta-regression included 38 studies with a total of 3072 patients. Significant heterogeneity in retear rates was found among the studies (Q = 209.53, I 2 = 82.34, P < .001). By use of a random-effects model, the retear rate point estimate was 22.1% (95% confidence interval [CI], 18.6%-26.0%). On univariate analysis, type of imaging modality did not significantly influence the retear rate (P = .188). On univariate analysis, mean age (odds ratio [OR], 1.05 [95% CI, 1.01-1.09]; P = .027) and mean time to imaging (OR, 1.04 [95% CI, 1.01-1.08]; P = .006) were associated with the retear rate. Publication year (OR, 0.94 [95% CI, 0.88-1.01]; P = .083) demonstrated a trend toward significance. On multivariate analysis, increased age was associated with a 5%/yr increased odds of retear (OR, 1.05 [95% CI, 1.01-1.08]; P = .025). The risk of retear doubled from 15% at age 50 years to >30% at age 70 years. Time to imaging demonstrated a trend toward increased odds of retear (OR, 1.03 [95% CI, 1.00-1.07]; P = .056). Publication year was not associated with the retear rate on multivariate analysis (OR, 0.96 [95% CI, 0.90-1.02]; P = .195). CONCLUSION: The risk of retear after rotator cuff repair is associated with increased age and doubles between the ages of 50 and 70 years.

Staged vs Concurrent Hardware Removal During Conversion Total Knee Arthroplasty.

BACKGROUND: Conversion total knee arthroplasty (TKA) in the presence of periarticular hardware can be associated with increased resource utilization, complications, and revisions. However, little guidance exists on the optimal approach to hardware removal. The purpose of this study is to compare outcomes of conversion TKA with hardware removal performed in either a staged or concurrent manner. METHODS: This is a retrospective study of 155 TKA operations performed with staged (45) or concurrent (110) removal of hardware at the time of TKA. Differences in patient data, case data, complications, reoperations, and revisions were evaluated. Subgroup comparisons of cases involving major hardware (plates, nails, rods), minor hardware (screws, buttons, wires), and tibial plates were performed. RESULTS: There were no differences in age, sex, body mass index, or comorbidities between patients who underwent staged or concurrent hardware removal. Rates of complications, reoperations, and revisions did not differ at multiple time points (90 days, 1 year, 2 years, 4 years). Patients who underwent staged hardware removal were more likely to have had prior surgery for fracture reconstruction (68% vs 33%, P < .001), to have had major hardware removed (84% vs 59%, P = .03), and were less likely to have had hardware removal performed through a single incision with TKA (50% vs 92%, P < .001). Subgroup analysis of major and minor hardware cases demonstrated comparable outcomes. CONCLUSION: There remains no established benefit to either a staged or concurrent approach to hardware removal at the time of TKA. This is true regardless of hardware burden. At this time, a case-by-case approach should be taken to conversion TKA in the presence of periarticular hardware.

Effect of Patient Body Mass Index, Recommendation for Weight Modification, and Nonmodifiable Factors on Patient Satisfaction.

INTRODUCTION: Patient satisfaction serves an increasingly important role in health care. Multiple nonmodifiable patient factors have been found to influence patient satisfaction. To the best of our knowledge, however, no study has investigated the influence of body mass index (BMI) on satisfaction scores. The objective of this study was to evaluate whether BMI and provider recommendation for patient weight modification were associated with patient satisfaction. METHODS: We reviewed Press Ganey patient satisfaction survey scores from 3,044 clinical encounters in an academic orthopaedic center between November 2010 and May 2017. Multiple patient factors, BMI, and recommendation for weight loss, or requirement of weight loss, before surgery were recorded. Patient satisfaction was operationalized as a binary outcome of completely satisfied or not completely satisfied, and multiple logistic regression was used to estimate the odds of being completely satisfied from the subset of potential predictors. RESULTS: White patients (odds ratio [OR] = 1.340, 95% confidence interval [CI]: 1.113 to 1.584, P = 0.0007) and Medicare-insured patients (OR = 1.260, 95% CI: 1.044 to 1.521, P = 0.0164) were more likely to be completely satisfied, whereas patients being seen by a provider for the first time were less likely to be completely satisfied (OR = 0.728, 95% CI: 0.626 to 0.847, P < 0.0001). BMI, recommendation for weight loss, and requirement of weight modification before surgery were not found to be associated with patient satisfaction. DISCUSSION: Neither patient BMI nor provider recommendation for weight loss, or as a requirement for surgery, was associated with patient satisfaction. Race, insurance status, and previous visits with the care provider were identified as nonmodifiable patient factors that influence patient satisfaction. LEVEL OF EVIDENCE: Level III.

In Vivo analysis of spinopelvic kinematics and peak head-cup contact in total hip arthroplasty patients with lumbar degenerative disc disease.

Anterior instability after total hip arthroplasty (THA) has been described in patients with thoracolumbar kyphotic deformity. Although compensatory posterior pelvic tilt with subsequent increased functional anteversion has been described as the mechanism, there is a paucity of in vivo data. The purpose of our study was to compare pelvic tilt, anteversion, inclination, and position of head-cup contact points in patients with lumbar degenerative disc disease (DDD) and a matched patient cohort without DDD. A total of 50 THA, 18 hips with lumbar DDD and 32 hips without DDD, underwent CT imaging for 3D hip reconstruction. Component orientations and in vivo hip gait kinematics was quantified using a validated dual fluoroscopic imaging system. Hip kinematics and head-cup contact points were compared. Patients with lumbar DDD demonstrated decreased maximum (5.9° ± 4.2° vs. 9.3° ± 5.4°, p = 0.02) and minimum (2.4° ± 4.1° vs. 6.2° ± 5.6°, p = 0.01) anterior pelvic tilt, and increased maximum cup anteversion (29.3° ± 8.7° vs. 25.1° ± 8.1°, p = 0.05). The peak head-cup contact points were shifted closer to the anterior edge of the polyethylene (7.8 ± 1.7 mm vs. 9.6 ± 2.2 mm, p = 0.02). Patients with lumbar degenerative disc disease demonstrated increased posterior pelvic tilt, functional acetabular anteversion, inclination as well as shifting of the peak head-cup contact pattern significantly closer to an anterior edge, suggesting sagittal spinopelvic deformity may predispose to anterior instability in THA patients during upright activities. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.

Sleep Disturbance in Orthopaedic Trauma Patients.

OBJECTIVE: To evaluate the prevalence and severity of sleep disturbance experienced by patients who have sustained a traumatic orthopaedic injury, how sleep disturbance affects the patient's perceived health quality, and identify factors associated with sleep disturbance. DESIGN: Cross-sectional cohort study. SETTING: Urban Level I trauma center. PATIENTS/PARTICIPANTS: Three hundred thirty-five nonconsecutive patients who presented to clinic at various stages of treatment for their traumatic orthopaedic injuries. MAIN OUTCOME MEASUREMENTS: Pittsburgh sleep quality index (PSQI) and 36-item short form-36 (SF-36) survey questionnaires; injury severity score (ISS). RESULTS: The average PSQI score was 10.3 (±4.8). Two hundred eighty-eight (86.0%) patients had a PSQI score ≥5, indicating the presence of sleep disturbance. The PSQI score was ≥10 in 183 (54.6%) patients, which is sleep disturbance similar to the level seen in clinical depression. Patients reported an average sleep latency of 38.9 (±37.5) minutes, with a total nightly sleep time of 6.3 (±1.9) hours. Univariate statistical analysis demonstrated that age, time since injury, and all components of the SF-36 were significantly associated with increased PSQI scores. When these variables were assessed with multivariate analysis to control for confounding variables, the bodily pain, vitality, and mental health components of the SF-36 remained independently associated with PSQI (P ≤ 0.001, 0.002, and 0.001, respectively). ISS measurements at the time of presentation were not associated with PSQI scores. CONCLUSIONS: Our findings suggest that sleep disturbance is both highly prevalent (86% PSQI ≥5) and severe (54.6% PSQI ≥10) in patients recovering from a traumatic orthopaedic injury. The bodily pain, vitality, and mental health components of the SF-36 were independently associated with worse sleep quality. The average orthopaedic trauma patient presents with a sleep score similar to that seen in clinical sleep disorders and clinical depression. Interestingly, in our study, the severity of the overall injury burden as measured by ISS and time since injury were not independently associated with the severity of sleep disturbance, as one might expect. LEVEL OF EVIDENCE: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Venous Thromboembolism Prophylaxis after Total Knee Arthroplasty.

Venous thromboembolic disease (VTED) is a major cause of morbidity and mortality after total knee arthroplasty (TKA). Current VTED prophylaxis protocols consist of early mobilization, mechanical compression devices, and pharmacologic agents. Venous phasic flow-regulated below-knee devices are generally favored, but the optimal duration and method of mechanical prophylaxis is unknown. Risk stratification models have been developed to guide pharmacologic prophylaxis. For patients with standard VTED risk profile, aspirin has become increasingly popular. Recent studies have validated the efficacy, relatively low bleeding risks, and cost-effectiveness of aspirin in the patients with standard risk profile. Current evidence suggests that the newer oral anticoagulants, including the factor Xa and the direct thrombin inhibitors, are effective for the reduction of postoperative VTED but may be associated with increased bleeding and wound complication rates.

Multi-parametric muscle and fat correlation of computed tomography parameters to outcomes in a total hip arthroplasty population.

BACKGROUND: Cross-sectional imaging is not currently used in planning Total Hip Arthroplasty (THA). The aim of our study is to determine correlations between CT parameters and outcomes following THA. METHODS: A prospective registry of patients who underwent total joint arthroplasty was reviewed for patients who: (1) underwent THA, (2) had a CT between 1 year before and 6 months after surgery, and (3) completed perioperative WOMAC and Harris Hip Score (HHS) questionnaires. Two readers measured CT parameters, yielding mean Hounsfield Units, area, average diameter, and perimeter of the psoas major, gluteus medius and minimus muscles. A segmentation algorithm determined visceral and subcutaneous fat area, and waist circumference. ICC was calculated for each measurement to examine inter-reader agreement. Regression analyses were performed to select measurements with most impact on outcome scores. RESULTS: Twenty-eight patients met inclusion criteria (17 female, 11 male), having mean (+/- standard deviation) age of 54.4 +/- 14.8 years and BMI 29.0 +/- 6.3 kg/m2. Correlations were found between HHS and age (0.650, p = 0.018), height (-1.263, p = 0.009), visceral-to-subcutaneous fat area ratio at the psoas level (0.511, p = 0.018), and waist circumference at the psoas level (1.759, p = 0.002). Inter-reader analysis showed ICC > 0.850 for all measurements. CONCLUSION: Age and height, as well as CT-derived visceral-to-subcutaneous fat area ratio and waist circumference significantly correlate with postsurgical HHS scores following THA. Our study suggests that parameters derived from cross-sectional CT imaging can be useful additional preoperative planning tool for THA.

Tranexamic acid administration for anatomic and reverse total shoulder arthroplasty: a systematic review and meta-analysis.

BACKGROUND: Tranexamic acid (TXA) has been shown to reduce perioperative blood loss and risk of blood transfusion. Evidence establishing its efficacy in total shoulder arthroplasty (TSA) is limited. The current study evaluated the effect of TXA on perioperative blood loss and transfusion risk after TSA. METHODS: A systematic review and meta-analysis of TXA administration for TSA was performed, and 6 studies with a total of 680 patients were found. Data on change in hemoglobin, drain output, total blood loss, and transfusion were extracted. Meta-analysis was performed with stratification into reverse and anatomic TSA subgroups. RESULTS: TXA administration was associated with decreased change in hemoglobin (-0.63 g/dL; 95% CI, -0.87 to -0.39 g/dL; P < .00001), drain output (-112.05 mL; 95% CI, -182.29 to -41.81 mL; P < .0001), and total blood loss (-231.87 mL; 95% CI, -334.23 to -129.48 mL; P < .00001) after reverse TSA. There was a trend toward reduction in transfusion rate after reverse TSA (-4%; 95% CI, -8% to 0%; P = .06). TXA administration was associated with reduced drain output after anatomic TSA (-123.07 mL; 95% CI, -163.93 to -82.20 mL; P < 0.00001). TXA administration was not associated with decreased transfusion rate after anatomic TSA. Data to evaluate the effect of TXA on change in hemoglobin and total blood loss after anatomic TSA were insufficient. CONCLUSIONS: Routine administration of TXA reduces perioperative blood loss and may reduce the risk of transfusion after reverse TSA. Future studies are needed to further characterize its effect on the risk of transfusion after reverse TSA and efficacy in anatomic TSA.

Changes in the neurochemistry of athletes with repetitive brain trauma: preliminary results using localized correlated spectroscopy.

INTRODUCTION: The goal was to identify which neurochemicals differ in professional athletes with repetitive brain trauma (RBT) when compared to healthy controls using a relatively new technology, in vivo Localized COrrelated SpectroscopY (L-COSY). METHODS: To achieve this, L-COSY was used to examine five former professional male athletes with 11 to 28 years of exposure to contact sports. Each athlete who had had multiple symptomatic concussions and repetitive sub concussive trauma during their career was assessed by an experienced neuropsychologist. All athletes had clinical symptoms including headaches, memory loss, confusion, impaired judgment, impulse control problems, aggression, and depression. Five healthy men, age and weight matched to the athlete cohort and with no history of brain trauma, were recruited as controls. Data were collected from the posterior cingulate gyrus using a 3 T clinical magnetic resonance scanner equipped with a 32 channel head coil. RESULTS: The variation of the method was calculated by repeated examination of a healthy control and phantom and found to be 10% and 5%, respectively, or less. The L-COSY measured large and statistically significant differences (P ≤0.05), between healthy controls and those athletes with RBT. Men with RBT showed higher levels of glutamine/glutamate (31%), choline (65%), fucosylated molecules (60%) and phenylalanine (46%). The results were evaluated and the sample size of five found to achieve a significance level P = 0.05 and a power of 90%. Differences in N-acetyl aspartate and myo-inositol between RBT and controls were small and were not statistically significance. CONCLUSIONS: A study of a small cohort of professional athletes, with a history of RBT and symptoms of chronic traumatic encephalopathy when compared with healthy controls using 2D L-COSY, showed elevations in brain glutamate/glutamine and choline as recorded previously for early traumatic brain injury. For the first time increases in phenylalanine and fucose are recorded in the brains of athletes with RBT. Larger studies utilizing the L-COSY method may offer an in-life method of diagnosis and personalized approach for monitoring the acute effects of mild traumatic brain injury and the chronic effects of RBT.

Fiber diffraction data indicate a hollow core for the Alzheimer's aß 3-fold symmetric fibril.

Amyloid ß protein (Aß), the principal component of the extracellular plaques found in the brains of patients with Alzheimer's disease, forms fibrils well suited to structural study by X-ray fiber diffraction. Fiber diffraction patterns from the 40-residue form Aß(1-40) confirm a number of features of a 3-fold symmetric Aß model from solid-state NMR (ssNMR) but suggest that the fibrils have a hollow core not present in the original ssNMR models. Diffraction patterns calculated from a revised 3-fold hollow model with a more regular ß-sheet structure are in much better agreement with the observed diffraction data than patterns calculated from the original ssNMR model. Refinement of a hollow-core model against ssNMR data led to a revised ssNMR model, similar to the fiber diffraction model.