Comparative outcomes after treatment of peri-implant, periprosthetic, and interprosthetic femur fractures: which factors increase mortality risk?

Objectives: To compare mortality rates between patients treated surgically for periprosthetic fractures (PPF) after total hip arthroplasty (THA), total knee arthroplasty (TKA), peri-implant (PI), and interprosthetic (IP) fractures while identifying risk factors associated with mortality following PPF. Design: Retrospective. Setting: Single, Level II Trauma Center. Patients/Participants: A retrospective review was conducted of 129 consecutive patients treated surgically for fractures around a pre-existing prosthesis or implant from 2013 to 2020. Patients were separated into 4 comparison groups: THA, TKA, PI, and IP fractures. Intervention: Revision implant or arthroplasty, open reduction and internal fixation (ORIF), intramedullary nailing (IMN), percutaneous screws, or a combination of techniques. Main Outcome Measurements: Primary outcome measures include mortality rates of different types of PPF, PI, and IP fractures at 1-month, 3-month, 6-month, 1-year, and 2-year postoperative. We analyzed risk factors associated with mortality aimed to determine whether treatment type affects mortality. Results: One hundred twenty-nine patients were included for final analysis. Average follow-up was similar between all groups. The overall 1-year mortality rate was 1 month (5%), 3 months (12%), 6 months (13%), 1 year (15%), and 2 years (22%). There were no differences in mortality rates between each group at 30 days, 90 days, 6 months, 1 year, and 2 years (P-value = 0.86). A Kaplan-Meier survival curve demonstrated no difference in survivorship up to 2 years. Older than 65 years, history of hypothyroidism and dementia, and discharge to a skilled nursing facility (SNF) led to increased mortality. There was no survival benefit in treating patients with PPFs with either revision, ORIF, IMN, or a combination of techniques. Conclusion: The overall mortality rates observed were 1 month (5%), 3 months (12%), 6 months (13%), 1 year (15%), and 2 years (22%), and no differences were found between each group at all follow-up time points. Patients aged 65 and older with a history of hypothyroidism and/or dementia discharged to an SNF are at increased risk for mortality. From a mortality perspective, surgeons should not hesitate to choose the surgical treatment they feel most comfortable performing. Level of Evidence: Level III.

Comparison of Outcomes After Reverse Total Shoulder Arthroplasty in Patients With Proximal Humerus Fractures Versus Rotator Cuff Arthropathy.

INTRODUCTION: Indications for reverse total shoulder arthroplasty (rTSA) has expanded to encompass complex proximal humerus fractures (PHFs) in recent years. The purpose of this study was to report and assess whether PHF patients treated with rTSA could achieve similar functional outcomes and short-term survivorship to patients who underwent rTSA for rotator cuff arthropathy (RTCA). METHODS: All consecutive patients with a preoperative diagnosis of PHF or RTCA, 18 years or older, treated with rTSA at a single academic institution between 2018 and 2020 with a minimum 2-year follow-up were retrospectively reviewed. Primary outcomes were survivorship defined as revision surgery or implant failure analyzed using the Kaplan-Meier survival curve, and functional outcomes, which included Quick Disabilities of the Arm, Shoulder, and Hand, and range of motion (ROM) were compared at multiple follow-up time points up to 2 years. Secondary outcomes were patient demographics, comorbidities, surgical data, length of hospital stay, and discharge disposition. RESULTS: A total of 48 patients were included: 21 patients (44%) were diagnosed with PHF and 27 patients (56%) had RTCA. The Kaplan-Meier survival rate estimates at 3 years were 90.5% in the PHF group and 85.2% in the RTCA group. No differences in revision surgery rates between the two groups (P = 0.68) or survivorship (P = 0.63) were found. ROM was significantly lower at subsequent follow-up time points in multiple planes (P < 0.05). A greater proportion of patients in the PHF group received cement for humeral implant fixation compared with the RTCA group (48% versus 7%, P = 0.002). The mean length of hospital stay was longer in PHF patients compared with RTCA patients (2.9 ± 3.8 days versus 1.6 ± 1.8 days, P = 0.13), and a significantly lower proportion of PHF patients were discharged home (67% versus 96%, P = 0.015). CONCLUSION: The rTSA implant survivorship at 3 years for both PHF and RTCA patients show comparable results. At the 2-year follow-up, RTCA patients treated with rTSA were found to have better ROM compared with PHF patients.

Child Advocacy in Action: If Not You, Who? If Not now, When?

The notion that the physician has a responsibility to both the patient in their care and the community in which they reside has been a source of inspiration and tension within the profession for centuries. The profession of Pediatrics has uniquely incorporated advocacy into its training programs and will likely continue to incorporate advocacy into its professional standards for the foreseeable future. In this article, we review the history of advocacy within the profession, outline the skills needs for successful child health advocacy and offer examples of how advocacy combined with pediatric practice has improved the lives of children.

Direct versus indirect posterior malleolar fixation in the treatment of trimalleolar ankle fractures: Is there a difference in outcomes?

Purpose: The purpose of this study was to examine the differences in functional outcomes between direct and indirect surgical fixation methods of the posterior malleolus in the setting of trimalleolar fractures and identify any variables affecting patient outcomes. Methods: Primary outcomes were evaluated by PROMIS scores for short-term outcomes regarding total pain (TP) and total function (TF) comparing 40 patients with direct fixation with 77 with indirect fixation. Continuous variables were analyzed using t tests for parametric variables and the Mann-Whitney U test for nonparametric variables. Categorical variables were analyzed using a χ2 test. Univariate and multivariate linear regression models were performed to analyze factors that affect outcomes of TP and TF. Results: There was no difference in TP or TF between groups (P = 0.65 vs. P = 0.19). On univariate linear regression for TP, BMI, incidence of complication, tobacco use, and open injury showed significance in increasing pain levels with open injuries providing the greatest effect (coef = 11.8). On multivariate analysis, BMI, incidence of complication, open injury, and tourniquet time all significantly increased pain. For TF, univariate analysis showed age, BMI, incidence of complication, and diabetes to decrease function, and use of external fixator and tourniquet time increased function. In the multivariate model, increased BMI, open injuries, and increasing tourniquet time all decreased TF while use of an external fixator increased TF. Conclusion: This study showed no difference in TP and TF using the PROMIS outcome scores when comparing direct fixation versus indirect fixation under univariate and multivariate models. Level of Evidence: Therapeutic III.

Use of antibiotic-cement coated locking plates in the setting of periprosthetic infection and infected nonunion.

INTRODUCTION: In the setting of periprosthetic total hip and knee arthroplasty (THA/TKA) infection, plating of the femur may be necessary for fracture fixation, prophylactic fixation of the femur, poor bone quality, or infected femoral shaft nonunion. The purpose of this study was to investigate infection control rates and fracture healing in patients receiving antibiotic cement coated plates in the setting of infected nonunion and periprosthetic infections. METHODS: We retrospectively reviewed a series of ten patients who had an antibiotic coated plate placed in the setting of periprosthetic infection or infected nonunion with a minimum follow-up of six months. 80 g of Simplex bone cement (Stryker, Mahwah, NJ) were mixed with 4 g of powdered vancomycin and 4.8 g of powdered tobramycin and applied to a dynamic compression plate with locking screw guides in every hole. The antibiotic loaded cement was allowed to harden before implantation. Outcome measures were designed to assess for fracture healing defined as three out of four cortices united on radiographs along with bearing full weight without pain and evidence of infection control defined as normalized erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) in the absence of antibiotic treatment with no clinical signs of infection. RESULTS: Ten patients were treated with an antibiotic cement coated plate in the settings of infectious nonunion and periprosthetic infection and followed for an average of three years (mean 21.4 months, seven months to 61 months). Eight patients (80%) went on to successful control of infection after initial procedure. Two patients developed chronic drainage and had a second antibiotic spacer with antibiotic cement coated plate placed before the infection was controlled. All patients obtained successful control of infection at latest follow-up showing no clinical signs of infection, normalized laboratory markers, and negative culture results. There were no reported mechanical failures of the implant, fractures of the femur, or soft tissue complications. CONCLUSION: An antibiotic cement coated plating technique is a viable option for periprosthetic THA and TKA infections requiring plating of the femur or in patients with an infected nonunion.

Dual regulation of miR-375 and CREM genes in pancreatic beta cells.

MicroRNA-375 (miR-375) is upregulated in the islets of some diabetics and is correlated with poor outcome. Previous work in our laboratory showed that cyclic adenosine monophosphate (cAMP) reduces miR-375 expression and could provide a way to restore normal miR-375 levels, however the transcription repression mechanism is unknown. Using a chromatin immunoprecipitation assay we show that cAMP response element modulator (CREM) binds to the miR-375 promoter 3-fold above background and we find that CREM represses transcription from the miR-375 promoter 1.8-fold. While investigating miR-375 target genes we discovered that several microRNA:mRNA target prediction algorithms listed human CREM as a target gene of miR-375. The predicted binding site is conserved in primates but not in other species. We found that indeed miR-375 binds to the predicted site on human CREM and represses translation of a green fluorescent protein reporter gene by 30%. These findings suggest a primate-specific double-negative feedback loop, a mechanism that would keep these important ß-cell regulators in check.

Comparing Intramedullary Nailing Versus Locked Plating in the Treatment of Native Distal Femur Fractures: Is One Superior to the Other?

INTRODUCTION: Distal femur fractures make up < 1% of all fractures and 3-6% of all femur fractures. In the literature, both intramedullary nailing (IMN) and locked plating (LP) have shown favorable results, but there is no consensus on a gold standard. The purpose of this systematic review is to compare outcomes of native distal femur fractures treated via IMN versus LP in an effort to determine if one is superior to the other. METHODS: Systematic review of MEDLINE, EMBASE, and Cochrane Library databases was conducted according to PRISMA guidelines. Only articles published within the last ten years were included. Evidence and study quality were evaluated with the MQOE and Oxford Criteria. RESULTS: Forty-six articles were included in the review. Fractures treated with IMN were found to have a 93.9% union rate, an average time to union of 19.2 weeks, an average arc of motion of 105.1 degrees, with an average of 14.4 degrees of malalignment. Fractures treated with LP were found to have a 90.2% union rate, an average time to union of 20.5 weeks, an average arc of motion of 104 degrees, with an average of 12.6 degrees of malalignment. CONCLUSION: Compiled data comparisons revealed no differences in union rate, malalignment, time to union, average arc of motion, or complication rates requiring a return to the operating room. Until higher level randomized data is available, either IMN or LP are acceptable methods of treatment for native distal femur fractures.

Sympathetic transduction in humans: recent advances and methodological considerations.

Ever since their origin more than one half-century ago, microneurographic recordings of sympathetic nerve activity have significantly advanced our understanding of the generation and regulation of central sympathetic outflow in human health and disease. For example, it is now appreciated that a myriad of disease states exhibit chronic sympathetic overactivity, a significant predictor of cardiovascular morbidity and mortality. Although microneurographic recordings allow for the direct quantification of sympathetic outflow, they alone do not provide information with respect to the ensuing sympathetically mediated vasoconstriction and blood pressure (BP) response. Therefore, the study of vascular and/or BP responses to sympathetic outflow (i.e., sympathetic transduction) has now emerged as an area of growing interest within the field of neural cardiovascular control in human health and disease. To date, studies have primarily examined sympathetic transduction under two distinct paradigms: when reflexively evoking sympatho-excitation through the induction of a laboratory stressor (i.e., sympathetic transduction during stress) and/or following spontaneous bursts of sympathetic outflow occurring under resting conditions (i.e., sympathetic transduction at rest). The purpose of this brief review is to highlight how our physiological understanding of sympathetic transduction has been advanced by these studies and to evaluate the primary analytical techniques developed to study sympathetic transduction in humans. We also discuss the framework by which the assessment of sympathetic transduction during stress reflects a fundamentally different process relative to sympathetic transduction at rest and why findings from investigations using these different techniques should be interpreted as such and not necessarily be considered one and the same.

Reducing Dislocations of Antibiotic Hip Spacers via Hybrid Cement-screw Constrained Liner Fixation: A Case Series.

PURPOSE: Infection following total hip arthroplasty is a challenging and devastating complication. In two-stage revision arthroplasty, antibiotic spacers, although efficacious, can be associated with an unacceptable rate of mechanical complications (e.g., fracture, dislocation). This series describes 15 patients with infected total hip prostheses treated with hybrid cement-screw fixation constrained liner antibiotic spacers to enhance stability and minimize mechanical complications. MATERIALS AND METHODS: All patients with an infected hip prosthesis undergoing two-stage revision arthroplasty at a single academic medical center were identified and screened for inclusion. Clinical and radiographic data including patient demographics and outcome measures were collected and retrospectively analyzed. RESULTS: Two patients died of unrelated causes at an average of 6-week postoperatively. Infections in the remaining thirteen patients (100%) were successfully eradicated; all underwent uncomplicated revision arthroplasty at a mean duration of 99.5 days after the placement of the antibiotic spacer. No dislocations, fractures, or other mechanical failures of any spacer were observed in this series. CONCLUSION: The hybrid cement-screw fixation technique for constrained liner antibiotic spacers is a reliable and effective treatment method for eradicating prosthetic joint infections without mechanical complications.

Temporary External Fixation to Table as a Traction Reduction Aide in the Treatment of Unstable Pelvic Ring Injuries: A Technical Note.

Displaced pelvic ring injuries can be challenging to even the experienced orthopedic traumatologist. A temporary external fixation to table construct provides a quick, simple, and accessible means of external skeletal fixation to reliably obtain and maintain stable hemipelvis reduction on the operating room table. The contralateral hemipelvis can be stabilized to the table by use of Steinman pins safely inserted into the subtrochanteric and anterior column regions and later connected to external fixator bars attached to the table. With rigid stabilization, the displaced contralateral pelvic fragment(s) can be reduced in a more vector intentional manner with greater force than the traditional means of pelvic reduction can allow. The skeletal-table fixation technique is presented along with two cases, a combined pelvic-acetabular injury and an isolated pelvic ring injury.

Functional sympatholysis is preserved in healthy young Black men during rhythmic handgrip exercise.

Black men have attenuated increases in forearm vascular conductance (FVC) and forearm blood flow (FBF) during moderate- and high-intensity rhythmic handgrip exercise compared with White men, but the underlying mechanisms are unclear. Here, we tested for the first time the hypothesis that functional sympatholysis (i.e., attenuation of sympathetic vasoconstriction in the exercising muscles) is impaired in Black men compared with White men. Thirteen White and 14 Black healthy young men were studied. FBF (duplex Doppler ultrasound) and mean arterial pressure (MAP; Finometer) were measured at rest and during rhythmic handgrip exercise at 30% maximal voluntary contraction. FVC was calculated as FBF/MAP. Sympathetic activation was induced via lower body negative pressure (LBNP) at -20 Torr for 2 min at rest and from the 3rd to the 5th min of handgrip. Sympathetic vasoconstriction was assessed as percent reductions in FVC during LBNP. The groups presented similar resting FVC, FBF, and MAP. During LBNP at rest, reductions in FVC were not different between White (-35 ± 10%) and Black men (-32 ± 14%, P = 0.616), indicating similar reflex-induced sympathetic vasoconstriction. During handgrip exercise, there were minimal reductions in FVC with LBNP in either group (White: -1 ± 7%; Black: +1 ± 8%; P = 0.523), indicating functional sympatholysis in both groups. Thus, contrary to our hypothesis, our findings indicate a preserved functional sympatholysis in healthy young Black men compared with White men, suggesting that this mechanism does not appear to contribute to reduced exercise hyperemia during moderate-intensity rhythmic handgrip in this population.

Augmented resting beat-to-beat blood pressure variability in young, healthy, non-Hispanic black men.

NEW FINDINGS: What is the central question of this study? The prevalence of hypertension in black individuals exceeds that in other racial groups. Despite this well-known heightened risk, the underlying contributory factors remain incompletely understood. We hypothesized that young black men would exhibit augmented beat-to-beat blood pressure variability compared with white men and that black men would exhibit augmented total peripheral resistance variability. What is the main finding and its importance? We demonstrate that young, healthy black men exhibit greater resting beat-to-beat blood pressure variability compared with their white counterparts, which is accompanied by greater variability in total peripheral resistance. These swings in blood pressure over time might contribute to the enhanced cardiovascular risk profile in black individuals. ABSTRACT: The prevalence of hypertension in black (BL) individuals exceeds that in other racial groups. Recently, resting beat-to-beat blood pressure (BP) variability has been shown to predict cardiovascular risk and detect target organ damage better than ambulatory BP monitoring. Given the heightened risk in BL individuals, we hypothesized young BL men would exhibit augmented beat-to-beat BP variability compared with white (WH) men. Furthermore, given studies reporting reduced vasodilatation and augmented vasoconstriction in BL individuals, we hypothesized that BL men would exhibit augmented variability in total peripheral resistance (TPR). In 45 normotensive men (24 BL), beat-to-beat BP (Finometer) was measured during 10-20 min of quiet rest. Cardiac output and TPR were estimated (Modelflow method). Despite similar resting BP, BL men exhibited greater BP standard deviation (e.g. systolic BP SD; BL, 7.1 ± 2.2 mmHg; WH, 5.4 ± 1.5 mmHg; P = 0.006) compared with WH men, which was accompanied by a greater TPR SD (P = 0.003), but not cardiac output SD (P = 0.390). Other traditional measures of variability provided similar results. Histogram analysis indicated that BL men exhibited a greater percentage of cardiac cycles with BPs higher (> +10 mmHg higher) and lower (< -8 mmHg lower) than mean systolic BP compared with WH men (interaction, P < 0.001), which was accompanied by a greater percentage of cardiac cycles with high/low TPR (P < 0.001). In a subset of subjects (n = 30), reduced sympathetic baroreflex sensitivity was associated with augmented BP variability (r = -0.638, P < 0.001), whereas cardiac baroreflex sensitivity had no relationship (P = 0.447). Herein, we document an augmented beat-to-beat BP variability in young BL men, which coincided with fluctuations in vascular resistance and reduced sympathetic BRS.

Risk factors for liposomal bupivacaine resistance after total hip or knee arthroplasties: a retrospective observational cohort in 237 patients.

PURPOSE: Liposomal bupivacaine demonstrated promise decreasing postoperative pain in total hip and total knee arthroplasty (THA/TKA). Some randomized trials have shown non-superior results; however, confounding variables were not accounted for in such analyses. This study attempts to determine risk factors associated with failure of pain management in patients receiving liposomal bupivacaine. METHODS: Postoperative pain scores were collected following primary or revision arthroplasties between January 2016 and December 2017. Retrospective analysis of institutional total joint quality and outcomes registry was screened and patients undergoing primary or revision arthroplasties who completed a multi-modal pain management including liposomal bupivacaine were included in the study. Patients with a history of infection/deviated from the institutional pain management protocol were excluded. RESULTS: A total of 237 patients were included for analysis. Younger patients less than 64 years old had significantly higher pain scores between 0 and 12 h and > 24 h. Active smokers had significantly higher pain scores between 0 and 6 h and > 24 h. Patients with a history of opioid use/pain management had significantly higher pain scores at 6-12 h and 24-48 h. Regression analysis indicated risk factors for resistance to liposomal bupivacaine are younger patients less than 64 years old, those undergoing primary THA, and patients with a history of smoking/pain management/opioid use. CONCLUSION: We identify risk factors for resistance to liposomal bupivacaine, which include younger age less than 64 years old, history of smoking/pain management/opioid use. Future studies should use these risk factors as exclusion criteria when using liposomal bupivacaine or initiating any randomized trials regarding efficacy.

Racial disparities in cardiovascular disease risk: mechanisms of vascular dysfunction.

Cardiovascular disease (CVD) accounts for a third of all deaths in the United States making it the leading cause of morbidity and mortality. Although CVD affects individuals of all races/ethnicities, the prevalence of CVD is highest in non-Hispanic black (BL) individuals relative to other populations. The mechanism(s) responsible for elevated CVD risk in the BL population remains incompletely understood. However, impaired vascular vasodilator capacity and exaggerated vascular vasoconstrictor responsiveness are likely contributing factors, both of which are present even in young, otherwise healthy BL individuals. Within this review, we highlight some historical and recent data, collected from our laboratories, of impaired vascular function, in terms of reduced vasodilator capacity and heightened vasoconstrictor responsiveness, in the peripheral and cerebral circulations in BL individuals. We provide data that such impairments may be related to elevated oxidative stress and subsequent reduction in nitric oxide bioavailability. In addition, divergent mechanisms of impaired vasodilatory capacity between BL men and women are discussed. Finally, we propose several directions where future research is needed to fill in knowledge gaps, which will allow for better understanding of the mechanisms contributing to impaired vascular function in this population. Ultimately, this information will allow for better lifestyle and therapeutic approaches to be implemented in an effort to minimize the increased CVD burden in the BL population.

Sympathetic Transduction in Type 2 Diabetes Mellitus.

Approximately 60% of patients with type 2 diabetes mellitus (T2D) develop hypertension. Recent work also indicates greater blood pressure (BP) excursions throughout the day in T2D. Collectively, these findings suggest altered BP control in T2D. Although muscle sympathetic nerve activity (MSNA) recordings in T2D have provided equivocal results, quantification of MSNA alone does not account for ensuing vasoconstriction and BP responses elicited by MSNA. Thus, we tested the hypothesis that patients with T2D exhibit enhanced sympathetic transduction to BP. MSNA (microneurography) and beat-to-beat BP (Finometer) were measured at rest in 21 T2D and 13 age-matched and body mass index-matched control subjects and, signal-averaging was performed to quantify the mean arterial pressure and total vascular conductance responses to spontaneous bursts of MSNA. The peak mean arterial pressure and total vascular conductance responses to spontaneous MSNA were similar between T2D and control (both P>0.05). However, further analysis, separating T2D into those taking statins (n=13, T2D +statin) and not taking statins (n=8, T2D -statin), indicated that T2D -statin patients (4.2±0.6 mm Hg) exhibited greater peak mean arterial pressure responses compared with both T2D +statin patients (2.5±0.3 mm Hg, P=0.01) and control (control: 2.8±0.3 mm Hg, P=0.02). Likewise, nadir total vascular conductance responses to spontaneous MSNA bursts were greater in T2D -statin patients (T2D -statin: -3.3±0.6 mL/(min·mm Hg), T2D +statin: -1.6±0.3 mL/(min·mm Hg), P=0.03; control -2.2±0.3 mL/(min·mm Hg), P=0.08). Notably, T2D +statin patients exhibited similar peak mean arterial pressure and total vascular conductance responses to MSNA compared with control. Collectively, these findings demonstrate, for the first time, that patients with T2D exhibit augmented sympathetic transduction and this effect seems to be offset by statin therapy.

Attenuated forearm vascular conductance responses to rhythmic handgrip in young African-American compared with Caucasian-American men.

Previous studies have demonstrated that African-American (AA) individuals have heightened vasoconstrictor and reduced vasodilator responses under resting conditions compared with Caucasian-American (CA) individuals. However, potential differences in vascular responses to exercise remain unclear. Therefore, we tested the hypothesis that, compared with CA subjects, AA subjects would present an attenuated increase in forearm vascular conductance (FVC) during rhythmic handgrip exercise. Forearm blood flow (FBF; duplex Doppler ultrasound) and mean arterial pressure (MAP; finger photoplethysmography) were measured in healthy young CA ( n = 10) and AA ( n = 10) men during six trials of rhythmic handgrip performed at workloads of 4, 8, 12, 16, 20, and 24 kg. FVC (calculated as FBF/MAP), FBF, and MAP were similar between groups at rest (FVC: 63 ± 7 ml·min-1·100 mmHg-1 in CA subjects vs. 62 ± 7 ml·min-1·100 mmHg-1 in AA subjects, P = 0.862). There was an intensity-dependent increase in FVC during exercise in both groups; however, AA subjects presented lower FVC (interaction P < 0.001) at 8-, 12-, 16-, 20-, and 24-kg workloads (e.g., 24 kg: 324 ± 20 ml·min-1·100 mmHg-1 in CA subjects vs. 241 ± 21 ml·min-1·100 mmHg-1 in AA subjects, P < 0.001). FBF responses to exercise were also lower in AA subjects (interaction P < 0.001), whereas MAP responses did not differ between groups (e.g., ∆MAP at 24 kg: +19 ± 2 mmHg in CA subjects vs. +19 ± 2 mmHg in AA subjects, interaction P = 0.950). These findings indicate lower hyperemic responses to rhythmic handgrip exercise in AA men compared with CA men. NEW & NOTEWORTHY It is known that African-American individuals have heightened vasoconstriction and reduced vasodilation under resting conditions compared with Caucasian-American individuals. Here, we identified that the hyperemic response to moderate and high-intensity rhythmic handgrip exercise was lower in healthy young African-American men.