Predictors of Inpatient Mortality and Systemic Complications in Acetabular Fractures Requiring Operative Treatment

Patient demographics, physiologic variables, and injury characteristics predictive of mortality and major systemic complications following operative fixation of acetabulum fractures were identified using the National Sample Program of the National Trauma Data Bank. Age older than 60 years, obesity, and Injury Severity Score greater than 15 portended a statistically significant increase in mortality and major systemic complications (P≤.05). Systolic blood pressure less than 90 mm Hg and Glasgow Coma Scale score less than 8 were also significant predictors of mortality and major systemic complications (P<.0001). Time to surgery and hospital length of stay did not affect mortality. The most common potentially modifiable risk factors were smoking (22.3%) and obesity (body mass index ≥30 kg/m²) (9.1%). Increasing age, Injury Severity Score, and obesity independently predicted a statistically significant increase in both mortality and major systemic complications. A better understanding of the associated risk factors and unique complication profile will provide orthopedic surgeons with a basis on which to effectively counsel and care for patients. [Orthopedics. 2017; 40(2):e223-e228.].

Tibial Tubercle Osteotomy for Patellar Chondral Pathology in an Active United States Military Population

PURPOSE

To quantify rates of perioperative complications, secondary surgery, subjective pain relief, and knee-related medical separation in an active military population after a tibial tubercle osteotomy (TTO) for the primary indication of chondral pathology.

METHODS

All active-duty service members undergoing TTO with a minimum of 2 years' follow-up were isolated from the Military Health System database. The exclusion criteria were patients with patellar instability, other periarticular osteotomy, and insufficient follow-up. Demographic information and surgical characteristics were abstracted from the electronic health record and correlated with improvement in pain and medical discharge from the military.

RESULTS

A total of 76 patients (86 knees) who underwent TTO for patellofemoral chondromalacia were identified with a mean age of 32.3 years. Major and minor complications occurred in four patients (4.7%) and three patients (3.5%), respectively, and the overall improvement in the visual analog scale score after TTO was 1.5 (P < .0001). At a mean follow-up of 3.4 years (range, 2.0 to 7.3 years), 37% of patients were unable to return to modified military activity because of knee-related limitations. Junior military rank group (P = .0084), age younger than 35 years (P = .0031), bilateral TTO procedures (P = .0294), and tobacco use (P = .0218; odds ratio, 3.29; 95% confidence interval, 1.19 to 9.12) were risk factors for medical separation, whereas absence of concomitant chondral repair (P = .5408), previous knee procedures (P = .9674), and greater occupational demands (P = .7062) were not.

CONCLUSIONS

At short-term to midterm follow-up, 63% of patients successfully returned to military function with a low rate of perioperative complications (8%). The postoperative decrease in pain after TTO is of unknown clinical significance. Age younger than 35 years, junior military rank, bilateral TTO procedures, and tobacco use were significant risk factors for medical separation, whereas absence of concomitant cartilage repair, previous knee procedures, and lower occupational demands were not associated with improved visual analog scale scores or prevention of knee-related medical discharge.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Characterization of Metacarpal Fractures in a Military Population

The purpose of this study was to investigate the incidence and type of metacarpal (MC) fractures in a military population, and whether these fractures are related to age, military occupational specialty, aggression, or accidental injury. A retrospective record-based review was conducted at a single military center over a 5-year period. Service members with index finger through small finger MC fracture were identified. Data were collected utilizing Armed Forces Health Longitudinal Technology Application and electronic profile (e-profile) databases. Data collected included demographic information, mechanism of injury, nature of injury, total number of visits, and estimated time on physical restriction. 400 patients met inclusion criteria. Males accounted for 94% of the study population, 75% of fractures were of the small finger MC, 54% of patients were between 20 and 24 years, 90% were sustained by junior enlisted personnel, and most occurred by punching. Men aged <25 years were more likely to have intentional injuries. Total time on limited duty profile averaged 38 days and the average medically nondeployable profile was 26 days. MC fractures most commonly affect young, male, junior enlisted service members and are often self-inflicted. As a result, these injuries account for time lost at work, reduced job performance, and decreased medical readiness.

Long versus short cephalomedullary nail for trochanteric femur fractures (OTA 31-A1, A2 and A3): a systematic review

BACKGROUND

Both long and short cephalomedullary nails (CMN) may be used to treat trochanteric femur fractures. The objective of this paper was to compare the clinical outcomes between long and short CMN in the treatment of trochanteric hip fractures.

MATERIALS AND METHODS

A literature search was performed, identifying 135 papers; 4 of which met inclusion and exclusion criteria. Papers included were those that compared cohorts of long and short nails for stable trochanteric femur fractures of level III evidence or superior. Data was pooled and analyzed, focusing on reoperation rate, secondary femoral shaft fracture rate, estimated blood loss, transfusion rate, operative time and length of stay.

RESULTS

Included in the analysis were 1276 patients, with 438 short and 838 long CMN. The average age was 82.0 years for short CMN and 79.0 years for long CMN (P = 0.0002). The average follow up was 18 months, 46 % were male, and 71 % had an ASA (American Society of Anesthesiologists score) classification ≥3. The rate of reoperation was 5.0 % and 3.8 % for short and long CMN, respectively (P = 0.31). The rate of refracture was 1.6 % and 0.95 % for short and long CMN, respectively (P = 0.41). As compared to long nails, short nails had an average blood loss of 39 mL less (P = 0.0003), an 8.8 % decrease in transfusion rate (P = 0.07), and incurred 19 min less operative time (P < 0.0001). No significant differences between short and long nails were observed for either other complications, hardware complications, non-union, or mortality.

CONCLUSIONS

For trochanteric femur fractures, short CMN have a low reoperation rate while significantly decreasing operative time and estimated blood loss with the additional benefit of being cost effective.

LEVEL OF EVIDENCE

Level 3.

Correlating HIV tropism with immunological response under combination antiretroviral therapy

OBJECTIVES

A significant percentage of patients infected with HIV-1 experience only suboptimal CD4 cell recovery while treated with combination therapy (cART). It is still unclear whether viral properties such as cell tropism play a major role in this incomplete immune response. This study therefore intended to follow the tropism evolution of the HIV-1 envelope during periods of suppressive cART.

METHODS

Viruses from two distinct patient groups, one with good and another one with poor CD4 recovery after 5 years of suppressive cART, were genotypically analysed for viral tropism at baseline and at the end of the study period.

RESULTS

Patients with CCR5-tropic CC-motif chemokine receptor 5 viruses at baseline tended to maintain this tropism to the study end. Patients who had a CXCR4-tropic CXC-motif chemokine receptor 4 virus at baseline were overrepresented in the poor CD4 recovery group. Overall, however, the majority of patients presented with CCR5-tropic viruses at follow-up.

CONCLUSIONS

Our data lend support to the hypothesis that tropism determination can be used as a parameter for disease progression even if analysed long before the establishment of a poorer immune response. Moreover, the lasting predominating CCR5-tropism during periods of full viral control suggests the involvement of cellular mechanisms that preferentially reduce CXCR4-tropic viruses during cART.

The effect of operative technique on ulnar nerve strain following surgery for cubital tunnel syndrome

BACKGROUND

The aim of this study is to compare the amount of strain on the ulnar nerve based on elbow position after in situ release, subcutaneous transposition, submuscular transposition, and medial epicondylectomy.

METHODS

Six matched cadaver upper extremity pairs underwent ulnar nerve decompression, transposition in a sequential fashion, while five elbows underwent medial epicondylectomy. A differential variable reluctance transducer (DVRT) was placed in the ulnar nerve. An in situ release, a subcutaneous transposition, and a submuscular transposition were performed sequentially with the strain being measured after each procedure in neutral, full elbow flexion, and extension positions. The strain was then averaged and compared for each procedure. Five cadavers underwent medial epicondylectomy and were similarly tested.

RESULTS

After the in situ release, there was no statistically significant change in strain in either flexion or extension. After a subcutaneous transposition, there was a statistically significant decrease in strain in full elbow flexion but not in extension. Similarly after a submuscular transposition, there was a statistically significant decrease in strain in full flexion but not in extension. There was not a statistically significant change in strain with medial epicondylectomy.

CONCLUSION

An in situ release of the ulnar nerve at the elbow may relieve pressure on the nerve but does not address the problem of strain which may be the underlying pathology in many cases of ulnar neuropathy at the elbow (UNE). Transposition of the ulnar nerve anterior to the medial epicondyle addresses the problem of strain on the ulnar nerve. In addition, it does not create an increased strain on the ulnar nerve with elbow extension.

Arthroscopic Shoulder Surgical Simulation Training Curriculum: Transfer Reliability and Maintenance of Skill Over Time

BACKGROUND

Surgical education is evolving as work hour constraints limit the exposure of residents to the operating room. Potential consequences may include erosion of resident education and decreased quality of patient care. Surgical simulation training has become a focus of study in an effort to counter these challenges. Previous studies have validated the use of arthroscopic surgical simulation programs both in vitro and in vivo. However, no study has examined if the gains made by residents after a simulation program are retained after a period away from training.

METHODS

In all, 17 orthopedic surgery residents were randomized into simulation or standard practice groups. All subjects were oriented to the arthroscopic simulator, a 14-point anatomic checklist, and Arthroscopic Surgery Skill Evaluation Tool (ASSET). The experimental group received 1 hour of simulation training whereas the control group had no additional training. All subjects performed a recorded, diagnostic arthroscopy intraoperatively. These videos were scored by 2 blinded, fellowship-trained orthopedic surgeons and outcome measures were compared within and between the groups. After 1 year in which neither group had exposure to surgical simulation training, all residents were retested intraoperatively and scored in the exact same fashion. Individual surgical case logs were reviewed and surgical case volume was documented.

RESULTS

There was no difference between the 2 groups after initial simulation testing and there was no correlation between case volume and initial scores. After training, the simulation group improved as compared with baseline in mean ASSET (p = 0.023) and mean time to completion (p = 0.01). After 1 year, there was no difference between the groups in any outcome measurements.

CONCLUSION

Although individual technical skills can be cultivated with surgical simulation training, these advancements can be lost without continued education. It is imperative that residency programs implement a simulation curriculum and continue to train throughout the academic year.

Pentafluoroethyl-substituted α-silanes: model compounds for new insights

To further investigate the α-effect in silanes bearing a geminal donor atom, the model compounds (C2F5)3SiCH2NMe2, (C2F5)3SiCH2OMe and (C2F5)3SiONMe2 were prepared by introduction of pentafluoroethyl groups via nucleophilic substitution of the corresponding chloro-derivatives with pentafluoroethyl lithium. The substances were characterised by NMR spectroscopy and X-ray diffraction via in situ crystallization techniques. The solid state structures of these highly electronegatively substituted α-silanes contain monomeric molecules. The Si-C-N angle in (C2F5)3SiCH2NMe2 shows a value of 115.3(2)° and the Si-C-O angle in (C2F5)3SiCH2OMe a value of 105.4(1)°. Both values are smaller than the Si-C-C angle of the reference compound (C2F5)3SiCH2CH3 with a value of 118.6(2)° indicating attractive interaction between the silicon atom and the respective donor atoms. The Si-O-N angle in (C2F5)3SiONMe2 is extremely narrow at 82.0(1)°. This behaviour was further investigated by gas electron diffraction and by quantum-chemical calculations. The NBO method finds no significant orbital interactions between Si and N/O atoms in the Si-C-N, Si-C-O and Si-O-N units. The IQA model describes the compounds as strongly stabilised by electrostatic interactions between formally non-bonded silicon and donor atoms.

Transition Metal Complexes of Phosphinous Acids Featuring a Quasichelating Unit: Synthesis, Characterization, and Hetero-bimetallic Complexes

Diorganophosphane oxides were employed as preligands for the synthesis of catalytically active transition metal complexes of the phosphinous acids (CF3)2POH and (C2F5)2POH. Their reactions with solid PtCl2 and PdCl2 led to the formation of mononuclear phosphinous acid complexes [Cl2M{P(R(f))2OH}2] (M = Pd, Pt; R(f) = C2F5, CF3), which can be crystallized, for example, as its pyridinium salts, 2[HPy](+)[Cl2Pd{P(CF3)2O}2](2-). In vacuo HCl is liberated from the neutral palladium complexes affording mixtures of di- and polynuclear complexes. Moreover, (C2F5)2POH was reacted with several β-diketonato complexes of palladium, platinum, and nickel yielding air- and moisture-stable complexes [(acac)M{[P(R(f))2O]2H}], featuring a quasichelating phosphinous acid phosphinito unit {P(R(f))2O···H···O(R(f))2P}(-). Treatment of [Ni(Cp)2] (Cp = cyclopentadienyl) and [(cod)RhCl]2 (cod = 1,5-cyclooctadiene) with (C2F5)2POH leads to the substitution of one Cp or chloro ligand by a quasichelating unit. The novel coordination compounds were characterized by NMR and IR spectroscopies, mass spectrometry, and X-ray diffraction analysis. The platinum complex [(acac)Pt{[P(C2F5)2O]2H}] (acac = acetylacetonato) was used for the construction of hetero-bimetallic complexes by the treatment with [(cod)RhCl]2 and [Ni(Cp)2]. The trinuclear bimetallic complex [{(acac)Pt[P(C2F5)2O]2}2Ni] is the first structurally characterized hetero-bimetallic species containing a bis(perfluoroalkyl)phosphinito bridge.

Predictors of length of stay after elective total shoulder arthroplasty in the United States

BACKGROUND

Total shoulder arthroplasty (TSA) is an increasingly used treatment of glenohumeral arthritis and proximal humerus fractures. However, patient-specific characteristics affecting length of hospital stay postoperatively have not been elucidated.

METHODS

All patients undergoing primary unilateral TSA between 2005 and 2011 were isolated from the National Surgical Quality Improvement Program database. Patient demographics, medical comorbidities, and selected surgical variables were extracted, and length of stay was established as the primary end point of interest. Risk factors were expressed as odds ratios (ORs) with 95% confidence intervals by bivariate and multivariable analysis.

RESULTS

A total of 2004 patients were identified; the average age was 68.8 years, and 57% were women. Mean length of stay after TSA was 2.2 days (standard deviation, 1.7), and 91% of cases received hospital discharge in <3 days. Multivariable logistic regression analysis identified renal insufficiency (OR, 11.35; P = .0002), increased age (OR, 2.13; P = .011), longer operative time (OR, 1.94; P = .0041), and American Society of Anesthesiologists class ≥3 (OR, 1.86; P = .0016) as the most significant risk factors for length of stay. Gender also influenced length of stay; women were more likely to stay ≥4 days (OR, 0.44; P < .0001).

CONCLUSIONS

Perioperative risk stratification and preoperative counseling are paramount for patients undergoing TSA, particularly for those individuals with cardiac and renal disease or of advancing age. These variables may effectively predict prolonged hospital stay after TSA.

Correction: Pentafluoroethyl-substituted α-silanes: model compounds for new insights

Correction for ‘Pentafluoroethyl-substituted α-silanes: model compounds for new insights’ by Benedikt Waerder et al., Dalton Trans., 2015, 44, 13347–13358.

Thirty-day morbidity and mortality after elective total shoulder arthroplasty: patient-based and surgical risk factors

BACKGROUND

Total shoulder arthroplasty (TSA) is an effective treatment for painful glenohumeral arthritis, but its morbidity has not been thoroughly documented.

METHODS

The National Surgical Quality Improvement Program database was queried to identify all patients undergoing primary TSA between 2006 and 2011, with extraction of selected patient-based or surgical variables and 30-day clinical course. Postoperative complications were stratified as major systemic, minor systemic, major local, and minor local, and mortality was recorded. Odds ratios (ORs) with 95% confidence intervals (95% CIs) were derived from bivariate and multivariable analysis to express the association between risk factors and clinical outcomes.

RESULTS

Among the 2004 patients identified, the average age was 69 years, and 57% were women. Obesity was present in 46%, and 48% had an American Society of Anesthesiologists classification of ≥3. The 30-day mortality and total complication rates were 0.25% and 3.64%, respectively. Comorbid cardiac disease (OR, 85.31; 95% CI, 8.15, 892.84) and increasing chronologic age (OR, 1.19; 95% CI, 1.06, 1.33) were independent predictors of mortality, whereas peripheral vascular disease was associated with statistically significant increase in any complication (OR, 6.25; 95% CI, 1.24, 31.40). Operative time >174 minutes was an independent predictor for development of a major local complication (OR, 4.05; 95% CI, 1.45, 11.30). Obesity was not associated with any specified complication after controlling for other variables.

CONCLUSIONS

Whereas TSA has low short-term rates of perioperative complications and mortality, careful perioperative medical optimization and efficient surgical technique should be emphasized to decrease morbidity and mortality.

Synthesis of functional phosphates [P(C2F5)3F2X]- from the phosphorane adduct [P(C2F5)3F2(dmap)]

Weakly coordinating anions (WCAs) are of great academic as well as industrial interest. To advance the fluoroalkyl phosphate anion [P(C2F5)3F3](-), which is ideally suited for technical applications, functional substituents X are attached to the Lewis acid (C2F5)3PF2. In keeping with this, the reaction of (C2F5)3PF2 with 4-(dimethylamino)pyridine (DMAP) yields the corresponding adduct [P(C2F5)3F2(dmap)]. Treatment of this adduct with Brønsted acids (HX) leads to the selective formation of the corresponding phosphate anions [P(C2F5)3F2X](-) by trapping the proton with the liberated base DMAP. In this way, OH functions can be transformed in one step into WCAs, slightly increasing the coordination properties of the corresponding anion. An ion exchange to the corresponding [PPh4] salts results in solids, whereas the corresponding imidazolium salts are obtained as room-temperature ionic liquids.

Synthesis of tris- and tetrakis(pentafluoroethyl)silanes

The synthesis and complete characterization of functional, highly Lewis acidic tris(pentafluoroethyl)silanes as well as tetrakis(perfluoroalkyl)silanes Si(C2F5)4 and Si(C2F5)3 CF3 by direct fluorination is described. The reaction of SiCl4 with LiC2F5 invariably affords (pentafluoroethyl)fluorosilicates. To avoid silicate formation by fluoride transfer from LiC2F5 the Lewis acidity of the silane has to be decreased by electron-donating substituents, such as dialkylamino groups. The easily accessible Si(C2F5)3 NEt2 is a valuable precursor for a series of tris(pentafluoroethyl)silanes.

Positive effect of reduced aeration rate on secretion of alpha-amylase and neutral proteases during pressurised fermentation of thermophilic Bacillus caldolyticus

The thermophilic microorganism Bacillus caldolyticus was incubated in laboratory scale stirred bioreactors under pressurised conditions at different aeration rates. Increased amounts of CO2/bicarbonate were solubilised under the chosen conditions. A reduction in aeration rate from 1 vvm to 0.1 vvm resulted in accumulation of CO2 and bicarbonate up to 126 mg l(-1) and 733 mg l(-1), respectively and also increased secretion of α-amylase and neutral proteases (increases of 123% and 52%, respectively). In this paper, the effect of reduced aeration rate on CO2/bicarbonate concentration and enzyme activities is presented. The selected fermentation conditions are closely related to those prevalent in large scale bioreactors and may offer the possibility of achieving high enzyme yields at reduced aeration costs on an industrial scale.

Effects of copper sulfate on seedlings of Prosopis pubescens (screwbean mesquite)

Phytoextraction is an established method of removal of heavy metals from contaminated soils worldwide. Phytoextraction is most efficient if local plants are used in the contaminated site. We propose that Prosopis pubescens (Screw bean mesquite) would be a successful phytoextractor of copper in our local soils. In order to determine the feasibility of using Screw bean mesquite, we utilized inductively-coupled plasma-optical emission spectroscopy (ICP-OES) and elemental analysis to observe the uptake of copper and the effects on macro and micro nutrients within laboratory-grown seedlings. We have previously shown that P. pubescens is a hyperaccumulator of copper in soil-grown seedlings. Light and transmission electron microscopy demonstrated death of root cells and ultrastructural changes due to the presence of copper from 50 mg/L - 600 mg/L. Ultrastructural changes included plasmolysis, starch accumulation, increased vacuolation and swollen chloroplasts with disarranged thylakoid membranes in cotyledons. Inductively coupled plasma-optical emission spectroscopy analyses of macro- and micro-nutrients revealed that the presence of copper sulfate in the growth medium of Petri-dish grown Prosopis pubescens seedlings resulted in dramatic decreases of magnesium, potassium and phosphorus. At 500-600 mg/L of copper sulfate, a substantial increase of sulfur was present in roots.

Prosopis pubescens (screw bean mesquite) seedlings are hyperaccumulators of copper

Due to health reasons, toxic metals must be removed from soils contaminated by mine tailings and smelter activities. The phytoremediation potential of Prosopis pubescens (screw bean mesquite) was examined by use of inductively-coupled plasma optical emission spectroscopy. Transmission electron microscopy was used to observe ultrastructural changes of parenchymal cells of leaves in the presence of copper. Elemental analysis was used to localize copper within leaves. A 600-ppm copper sulfate exposure to seedlings for 24 days resulted in 31,000 ppm copper in roots, 17,000 ppm in stems, 11,000 in cotyledons and 20 ppm in the true leaves. For a plant to be considered a hyperaccumulator, the plant must accumulate a leaf-to-root ratio <1. Screw bean mesquite exposed to copper had a leaf-to-root ratio of 0.355 when cotyledons were included. We showed that P. pubescens grown in soil is a hyperaccumulator of copper. We recommend that this plant should be field tested.