Predictors of Abdominal Aortic Aneurysm Shrinkage after Endovascular Repair

Recent studies demonstrate that patients with a shrinking abdominal aortic aneurysm (AAA), one-year after endovascular repair (EVAR), have better long-term outcomes than patients with a stable AAA. It is not known what factors determine whether an AAA will shrink or not. In this study, a range of parameters was investigated to identify their use in differentiating patients that will develop a shrinking AAA from those with a stable AAA one-year after EVAR. Hundred-seventy-four patients (67 shrinking AAA, 107 stable AAA) who underwent elective, infrarenal EVAR were enrolled between 2011-2018. Long-term survival was significantly better in patients with a shrinking AAA, compared to those with a stable AAA (p = 0.038). Larger preoperative maximum AAA diameter was associated with an increased likelihood of developing AAA shrinkage one-year after EVAR-whereas older age and larger preoperative infrarenal β angle were associated with a reduced likelihood of AAA shrinkage. However, this multivariate logistic regression model was only able to correctly identify 66.7% of patients with AAA shrinkage from the total cohort. This is not sufficient for implementation in clinical care, and therefore future research is recommended to dive deeper into AAA anatomy, and explore potential predictors using artificial intelligence and radiomics.

Long-term quality of life outcome after spondylodiscitis treatment

BACKGROUND CONTEXT

Spondylodiscitis is the most common spinal infection of which the incidence has increased and the peak prevalence is between 50 and 70 years of age. Spondylodiscitis is often a complication of a distant infection. Early diagnosis can be challenging, and although improvements in diagnostic techniques and modern therapy have diminished the mortality of the disease, current literature about the outcome of spondylodiscitis is scarce.

PURPOSE

To evaluate the long-term clinical outcome of patients who suffered from spondylodiscitis.

STUDY DESIGN

A two-center cross-sectional study.

PATIENT SAMPLE

Patients with spondylodiscitis in two large teaching hospitals in the Netherlands between 2003 and 2017.

OUTCOME MEASURES

Visual Analogue Scale (VAS) for back pain, Oswestry Disability Index (ODI) for function, and Short Form 36 (SF-36) for general quality of life of spondylodiscitis patients.

METHOD

Eligible patients were identified from electronic patient databases and completed multiple patient reported outcome measures after obtaining informed consent. General demographic and clinical information (age, sex, medical history) were extracted from the patient records. SF-36 domain scores of spondylodiscitis patients were compared with a nationwide population sample.

RESULTS

183 patients were treated for spondylodiscitis; additional questionnaires were received from 82 patients. After a median follow-up of 63 months, the overall mortality was 28%. The mean VAS for back pain was 3.5, and the mean ODI score was 22. In all SF-36 domains a significantly lower score was found in the spondylodiscitis group compared with a normative national Dutch cohort. There was a strong correlation between back pain and ODI scores (ρ=0.81, p<.05).

CONCLUSIONS

Our study confirms that spondylodiscitis is a disease causing a profound impact on back pain, function and quality of life. The results suggest that chronic back pain is a debilitating problem, as it has an extensive influence on daily activities and social and psychological well-being, causing significant disability.

Physical Function and Quality of Life After Resection of Mobile Spine Chondrosarcoma

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

(1) To assess patient-reported outcomes-physical function, pain, and quality of life-in patients who underwent resection of a mobile spine chondrosarcoma. (2) To assess complications (90 days), readmissions, reoperations, oncological outcomes, and neurologic status.

METHODS

Thirty-three patients with spinal conventional chondrosarcoma resection between 1984 and 2014 at one hospital were included. The primary outcome measures were-minimally 6 months after surgery-the EuroQol 5 Dimensions (EQ5D), PROMIS-Physical Function, PROMIS-Pain Intensity, and Oswestry (ODI) Disability Index, or Neck (NDI) Disability established in 14 out of 20 alive (70.0%) patients. Complications, readmission, reoperations, oncological outcomes, and neurological status were reported for the complete cohort of 33 patients.

RESULTS

After spine chondrosarcoma resection, patients (n = 14) reported worse physical function (median 43, range 22-61, P = .026), worse quality of life (median EQ5D 0.70, range 0.04-1, P = .022), and comparable pain intensity (median 47, range 31-56, P = .362) when compared with US general population values. The median NDI/ODI was 25 (range 0-72) indicating mild to moderate disability. Patients undergoing reoperation had worse patient-reported outcomes than those who did not. Eighteen (55.5%) out of 33 patients suffered complications (90 days), 14 (42.4%) had unplanned readmission, and 13 (39.4%) underwent reoperation. Intralesional resection was associated with increased readmission, reoperation, and recurrence rate.

CONCLUSIONS

Chondrosarcoma affects quality of life and physical function and its treatment frequently results in complications and reoperations. Our findings can be used to inform future patients about expected outcomes.

Incidental Flexor Carpi Radialis Tendinopathy on Magnetic Resonance Imaging

Background: Wrist pain is often nonspecific. Magnetic resonance imaging (MRI) is regularly obtained to evaluate wrist pain. Variations and pathophysiology identified on MRI may not account for patient's clinical symptoms. This study aims to quantify the prevalence of flexor carpi radialis (FCR) tendinopathy on MRI and the coexistence of trapeziometacarpal (TMC) or scaphotrapeziotrapezoid (STT) osteoarthritis. Methods: Using an institutional research database, we identified 3631 adult patients who obtained an MRI of the wrist during a 15-year period. Text search in the radiology reports identified 302 patients with possible FCR signal abnormalities. After reviewing the medical records, 98 patients were identified with FCR tendinopathy. Furthermore, medical records were used to identify pain located on the volar radial part of the wrist. In the absence of a documented examination consistent with FCR tendinopathy, we considered any signal change in the FCR incidental. Results: We identified 55 patients (55%) with incidental FCR tendinopathy. In a bivariate analysis, we found FCR signal changes on the MRI were associated with older age, white race, clinically suspected FCR tendinopathy, volar-radial sided wrist pain, and TMC and STT arthritis. Using multivariable logistic regression to account for confounding, older age and volar-radial sided wrist pain were independently associated with FCR signal changes on MRI. Conclusions: Signal changes in the FCR are infrequent and often incidental (asymptomatic) or associated with peritrapezial osteoarthritis.

The PROMIS Global Health Questionnaire Correlates With the QuickDASH in Patients With Upper Extremity Illness

BACKGROUND

The objective of this study is to evaluate the construct validity of the Patient-Reported Outcomes Measurement Information System (PROMIS) Global Health instrument by establishing its correlation to the Quick-Disabilities of the Arm, Shoulder and Hand (QuickDASH) questionnaire in patients with upper extremity illness.

METHODS

A cohort of 112 patients completed a sociodemographic survey and the PROMIS Global Health and QuickDASH questionnaires. Pearson correlation coefficients were used to evaluate the association of the QuickDASH with the PROMIS Global Health items and subscales.

RESULTS

Six of the 10 PROMIS Global Health items were associated with the QuickDASH. The PROMIS Global Physical Health subscale showed moderate correlation with QuickDASH and the Mental Health subscale. There was no significant relationship between the PROMIS Global Mental Health subscale and QuickDASH.

CONCLUSIONS

The consistent finding that general patient-reported outcomes correlate moderately with regional patient-reported outcomes suggests that a small number of relatively nonspecific patient-reported outcome measures might be used to assess a variety of illnesses. In our opinion, the blending of physical and mental health questions in the PROMIS Global Health makes this instrument less useful for research or patient care.

Variation in the Rate of Surgery for Ulnar Collateral Ligament Injury of the Metacarpophalangeal Joint of the Thumb

BACKGROUND

The indications for repair of rupture of the ulnar collateral ligament (UCL) of the metacarpophalangeal (MP) joint of the thumb are debated. We studied factors predictive of operative treatment.

METHODS

In this retrospective study, we queried the research database from 3 affiliated urban hospitals in a single city in the United States and identified 383 patients with a thumb MP UCL injury. We recorded age, sex, treating surgeon, and whether or not a magnetic resonance imaging (MRI) was ordered. If radiographs showed a concomitant avulsion fracture, we measured fragment size and displacement. Multivariable logistic regression was used to identify factors independently associated with surgery.

RESULTS

Surgery was independently associated with older patient age, widely displaced fractures (≥2 mm), and obtaining an MRI. Two specific surgeons were less likely to operate. Compared with patients without a fracture, fractures without displacement were less likely to have surgery.

CONCLUSIONS

The rate of surgery for acute thumb MP UCL injury varies based on patient characteristics and the individual treating surgeon. Variation might decrease with improved diagnostic techniques and consideration of practice guidelines. Future studies are needed to determine the patients and injuries that will benefit most from surgery.

Interpretation of Post-operative Distal Humerus Radiographs After Internal Fixation: Prediction of Later Loss of Fixation

PURPOSE

Stable fixation of distal humerus fracture fragments is necessary for adequate healing and maintenance of reduction. The purpose of this study was to measure the reliability and accuracy of interpretation of postoperative radiographs to predict which implants will loosen or break after operative treatment of bicolumnar distal humerus fractures. We also addressed agreement among surgeons regarding which fracture fixation will loosen or break and the influence of years in independent practice, location of practice, and so forth.

METHODS

A total of 232 orthopedic residents and surgeons from around the world evaluated 24 anteroposterior and lateral radiographs of distal humerus fractures on a Web-based platform to predict which implants would loosen or break. Agreement among observers was measured using the multi-rater kappa measure.

RESULTS

The sensitivity of prediction of failure of fixation of distal humerus fracture on radiographs was 63%, specificity was 53%, positive predictive value was 36%, the negative predictive value was 78%, and accuracy was 56%. There was fair interobserver agreement (κ = 0.27) regarding predictions of failure of fixation of distal humerus fracture on radiographs. Interobserver variability did not change when assessed for the various subgroups.

CONCLUSIONS

When experienced and skilled surgeons perform fixation of type C distal humerus fracture, the immediate postoperative radiograph is not predictive of fixation failure. Reoperation based on the probability of failure might not be advisable.

TYPE OF STUDY/LEVEL OF EVIDENCE

Diagnostic III.

What factors are associated with a second opioid prescription after treatment of distal radius fractures with a volar locking plate?

PURPOSE

Knowledge of factors associated with patient's requests for a second opioid prescription after volar plate fixation of a fracture of the distal radius might inform better pain management protocols and encourage decreased and safer use of opioids. This study tested the primary null hypothesis that there is no difference in demographics, prior opioid prescriptions, injury characteristics, and psychological factors between patients that do and do not receive a second opioid prescription following treatment volar locking plate after distal radius fracture.

PATIENTS AND METHODS

We used data on 206 patients enrolled in one of two prospective studies. Their mean age was 53 years ± SD 15, and 60 (30 %) were men. Forty-seven (23 %) patients received a second opioid prescription. We recorded additional demographics, AO fracture type, American Society for Anesthesiologists (ASA) classification, radiographic parameters at the time of injury prior to reduction and after surgery, and catastrophic thinking.

RESULTS

Male sex (odds ratio [OR] 2.2, 95 % confidence interval [CI] 1.0-4.6, partial pseudo R (2) = 0.018, P = 0.044) and greater dorsal angulation of the articular surface on the lateral post injury radiograph (OR 0.98, 95 % CI 0.96 to 1.0, partial pseudo R (2) = 0.033, P = 0.040) were associated with a second opioid prescription after surgery (pseudo R (2) 0.12, P = 0.0071).

CONCLUSIONS

One measure of fracture severity (dorsal displacement) was independently associated with a second opioid prescription, but alone it accounted for 3.3 % of the variation. Other factors such as the patient's expectation prior to surgery, in particular the realization that injury and surgery hurt, might be addressed in future research.

LEVEL OF EVIDENCE

Prognostic II.

Influence of Priming on Patient-Reported Outcome Measures: A Randomized Controlled Trial

BACKGROUND

Patient-reported outcome measures (PROMs) are influenced by psychosocial factors, but it is unknown whether we can influence PROM scores by modifying the mindset of the patient.

PURPOSE

We assessed whether priming affects scores on PROMs.

METHODS

In all, 168 patients with musculoskeletal illness participated in this double-blinded, randomized, controlled, parallel study between July 2014 and October 2014 in a level I trauma center. Inclusion criteria were patients aged 18 years or older with English fluency and literacy and the ability to provide informed consent. Priming was performed by means of the Pain Catastrophizing Scale (PCS). The patients were randomized (1:1:1) into 3 groups: intervention group I was negatively primed with the original PCS; intervention group II was positively primed with a positively phrased PCS group; and control group III was not primed. Assessments were performed using PROMs on the domain of physical function, depression, and pain. Bivariate and multivariable regression analyses were conducted.

RESULTS

The intervention and control groups were well balanced in demographic and condition-specific characteristics. The positive PCS was independently associated with higher PROM scores in the physical function domain (Patient-Reported Outcome Measurement Information System Upper Extremity Function: coefficient = 4.7, partial R(2) = 0.042; CI: 1.2-8.2; p < 0.010).

CONCLUSIONS

Patients primed with a positively phrased version of the PCS reported less functional disability as compared with patients who were either negatively primed or not primed at all. This suggests that by influencing the mindset, PROMs can be influenced, resulting in better outcome if positively primed.

LEVEL OF EVIDENCE

Level 1 therapeutic study.

TRIAL REGISTRATION

NCT02209259.

The relationship between impulsive choice and impulsive action: a cross-species translational study

Maladaptive impulsivity is a core symptom in various psychiatric disorders. However, there is only limited evidence available on whether different measures of impulsivity represent largely unrelated aspects or a unitary construct. In a cross-species translational study, thirty rats were trained in impulsive choice (delayed reward task) and impulsive action (five-choice serial reaction time task) paradigms. The correlation between those measures was assessed during baseline performance and after pharmacological manipulations with the psychostimulant amphetamine and the norepinephrine reuptake inhibitor atomoxetine. In parallel, to validate the animal data, 101 human subjects performed analogous measures of impulsive choice (delay discounting task, DDT) and impulsive action (immediate and delayed memory task, IMT/DMT). Moreover, all subjects completed the Stop Signal Task (SST, as an additional measure of impulsive action) and filled out the Barratt impulsiveness scale (BIS-11). Correlations between DDT and IMT/DMT were determined and a principal component analysis was performed on all human measures of impulsivity. In both rats and humans measures of impulsive choice and impulsive action did not correlate. In rats the within-subject pharmacological effects of amphetamine and atomoxetine did not correlate between tasks, suggesting distinct underlying neural correlates. Furthermore, in humans, principal component analysis identified three independent factors: (1) self-reported impulsivity (BIS-11); (2) impulsive action (IMT/DMT and SST); (3) impulsive choice (DDT). This is the first study directly comparing aspects of impulsivity using a cross-species translational approach. The present data reveal the non-unitary nature of impulsivity on a behavioral and pharmacological level. Collectively, this warrants a stronger focus on the relative contribution of distinct forms of impulsivity in psychopathology.

Cannabinoid CB1 receptor activation mediates the opposing effects of amphetamine on impulsive action and impulsive choice

It is well known that acute challenges with psychostimulants such as amphetamine affect impulsive behavior. We here studied the pharmacology underlying the effects of amphetamine in two rat models of impulsivity, the 5-choice serial reaction time task (5-CSRTT) and the delayed reward task (DRT), providing measures of inhibitory control, an aspect of impulsive action, and impulsive choice, respectively. We focused on the role of cannabinoid CB1 receptor activation in amphetamine-induced impulsivity as there is evidence that acute challenges with psychostimulants activate the endogenous cannabinoid system, and CB1 receptor activity modulates impulsivity in both rodents and humans. Results showed that pretreatment with either the CB1 receptor antagonist/inverse agonist SR141716A or the neutral CB1 receptor antagonist O-2050 dose-dependently improved baseline inhibitory control in the 5-CSRTT. Moreover, both compounds similarly attenuated amphetamine-induced inhibitory control deficits, suggesting that CB1 receptor activation by endogenously released cannabinoids mediates this aspect of impulsive action. Direct CB1 receptor activation by Δ9-Tetrahydrocannabinol (Δ9-THC) did, however, not affect inhibitory control. Although neither SR141716A nor O-2050 affected baseline impulsive choice in the DRT, both ligands completely prevented amphetamine-induced reductions in impulsive decision making, indicating that CB1 receptor activity may decrease this form of impulsivity. Indeed, acute Δ9-THC was found to reduce impulsive choice in a CB1 receptor-dependent way. Together, these results indicate an important, though complex role for cannabinoid CB1 receptor activity in the regulation of impulsive action and impulsive choice as well as the opposite effects amphetamine has on both forms of impulsive behavior.

Packing of elastic wires in spherical cavities

We investigate the morphologies and maximum packing density of thin wires packed into spherical cavities. Using simulations and experiments, we find that ordered as well as disordered structures emerge, depending on the amount of internal torsion. We find that the highest packing densities are achieved in low torsion packings for large systems, but in high torsion packings for small systems. An analysis of both situations is given in terms of energetics and comparison is made to analytical models of DNA packing in viral capsids.

Morphological phases of crumpled wire

We find that in two dimensions wires can crumple into different morphologies and present the associated morphological phase diagram. Our results are based on experiments with different metallic wires and confirmed by numerical simulations using a discrete element model. We show that during crumpling, the number of loops increases according to a power law with different exponents in each morphology. Furthermore, we observe a power law divergence of the structure's bulk stiffness similar to what is observed in forced crumpling of membranes.

Biophysical parameters modification could overcome essential hearing gaps

A majority of hearing defects are due to malfunction of the outer hair cells (OHCs), those cells within the mammalian hearing sensor (the cochlea) that provide an active amplification of the incoming signal. Malformation of the hearing sensor, ototoxic drugs, acoustical trauma, infections, or the effect of aging affect often a whole frequency interval, which leads to a substantial loss of speech intelligibility. Using an energy-based biophysical model of the passive cochlea, we obtain an explicit description of the dependence of the tonotopic map on the biophysical parameters of the cochlea. Our findings indicate the possibility that by suitable local modifications of the biophysical parameters by microsurgery, even very salient gaps of the tonotopic map could be bridged.

The cochlea, the mammalian hearing sensor, is a formidable biophysical construct in many respects. Its task is to pick up environmental auditory information, which provides us with a sensory communication channel without which we experience great problems in our every day life. In its extreme form, the lack of hearing capability often leads to social isolation. Mending hearing deficits—increasingly important in societies of growing average age—is difficult, not least because of a delicate interplay between the brain and the sensor. Here, we investigate to what extent the hearing sensor could be tuned in such a way that regions of malfunction are circumvented by relaying the signal to areas of normal functionality. The means by which we envisage achieving this goal is through local changes of the biophysical parameters of the cochlea. By investigation of a detailed biophysical model of the cochlea, we find that nature indeed appears to offer such a possibility.

Natural computation measured as a reduction of complexity

We argue that the deeper nature of computation is to reduce the statistical obstruction against prediction. From this, we derive an explicit measure of computation for general, artificial as well as natural, systems (electronic circuits, neurons, mechanical devices, etc.). The applicability and usefulness of this concept is demonstrated using well-studied families of dynamical systems, as well as experimental time series from cortical neurons.