Patient Expectations and Therapeutic Alliance Affect Pain Reduction Following Lidocaine Infusion in an Interdisciplinary Chronic Pain Clinic

Pain experience is affected by both ascending nociceptive signals and descending modulation. Expectations can affect pain experience and augment treatment-induced analgesia through descending inhibitory modulation of pain. This open-label, prospective cohort study examined the association between participant expectation ratings and pain reduction in adult participants with chronic pain receiving an intravenous lidocaine infusion. We aimed to explore whether: 1) participants' expectations of treatment efficacy were associated with pain reduction over 8 weeks after infusion; and 2) participants' therapeutic alliance was associated with expectations and/or pain reduction. We recruited 70 participants with chronic pain scheduled for lidocaine infusion. Study measures included pain intensity (pre-treatment, post-treatment, and daily for 8 weeks), treatment expectations (EXPECT), and therapeutic alliance (Trust in Physician and Working Alliance Inventory-Short Revised). Baseline treatment expectations were significantly correlated with pain reduction (r = .42, P < .01). Therapeutic alliance was significantly correlated with expectations (r = .27, P < .05) and pain reduction (r = .38, P < .01). This study quantifies the contribution of: 1) treatment expectations; and 2) therapeutic alliance to the magnitude of lidocaine-induced pain reduction. Results generate the hypothesis that focused efforts to augment treatment expectations and therapeutic alliance could serve to improve pain treatment outcomes. PERSPECTIVE: This study evaluates the relationship between pain reduction and ratings of: 1) treatment expectations; and 2) therapeutic alliance following an intravenous lidocaine infusion. Results generate the hypothesis that focused efforts to augment treatment expectations and therapeutic alliance could serve to improve pain treatment outcomes.

Correlation between dorsal capsulo-scapholunate septum (DCSS) lesion and predynamic scapholunate instability

OBJECTIVE

Scapholunate instability is the most common ligament injury of the wrist. In case of predynamic instability, diagnosis can be difficult, even under arthroscopy. Scapholunate instability is not the result of an isolated injury to the scapholunate interosseous ligament. Scapholunate stability is dependent not only on the scapholunate ligament, but on a complex that is comprising intrinsic and extrinsic ligaments. The dorsal capsule-scapholunate septum (DCSS) is one of the secondary stabilizers of the scapholunate complex. The objective of the present study was to investigate the correlation between DCSS lesion and predynamic scapholunate instability.

METHOD

A prospective multicenter study included patients who underwent wrist arthroscopy for traumatic wrist. Arthroscopic DCSS lesion stage and instability according to European Wrist Arthroscopy Society stage were assessed.

RESULTS

Twenty-seven subjects were included. We found a significant correlation between pathological DCSS and predynamic scapholunate instability and a correlation between DCSS lesion severity and instability level.

CONCLUSION

Isolated DCSS lesion should be considered a predictive factor for predynamic instability.

A prognostic classification of proximal humerus fractures: the cephalic extension staging

PURPOSE

Recent publications emphasized the role of dorsomedial metaphyseal extension of humeral head as predictor of ischemia after complex proximal humerus fractures (PHFs). We evaluated on preoperative 3D CT scan of PHFs the surface of this metaphyseal extension and its prognostic value on the occurrence of avascular necrosis (AVN).

METHODS

We followed a series of 25 fixations of complex PHF which had a preoperative 3D CT scan and measured the surface area of the posterior metaphyseal extension (PME) of the head. Using approximations, we calculated the ratio between the PME surface area (PMS) and the articular surface area of the head (HS). The PMS/HS ratio was analyzed against the risk of AVN.

RESULTS

The measurement of the PMS/HS ratio emphasizes the significance of PME. The incidence of AVN is correlated with the magnitude of PME. Therefore, we include the PME as a fifth element in the characterization of complex PHFs and we propose a 4-stage prognostic classification based on the number of extensions of the humeral head. The head may have 3 extensions: posteromedial (PME), lesser tuberosity (LTE) and greater tuberosity (GTE). The risk of AVN decreases with the number of extensions of the head.

CONCLUSION

Our study demonstrates a correlation between the occurrence of AVN and the size of PME in complex PHF cases. We propose a four-stage classification system to facilitate treatment decision-making between fixation and prosthesis.

A Study of Hand Flap Viability when Using a Wide Awake Local Anesthesia No Tourniquet (WALANT) Technique

Objectives  Flap surgery using a wide awake local anesthesia no tourniquet (WALANT) technique has historically been avoided because of technical challenges and concerns regarding the vasoconstriction caused by the necessary injection of epinephrine alongside the local anesthetic. The objective of our work was to evaluate the viability of the hand flaps performed using a WALANT technique compared with those performed under regional with a tourniquet. Materials and Methods  Seventy-four patients were enrolled in a prospective comparative single-center study and subsequently divided into two groups: 36 patients in the locoregional anesthesia group and 38 patients in the WALANT group. Flap viability was evaluated on day 2 and day 10 using predetermined criteria. Results  We did not find any significant difference in outcomes assessed for flap viability between the two groups postoperatively. Conclusion  There was no evidence to suggest that vascularization of the flaps was compromised by the injection of epinephrine. The WALANT technique may, therefore, potentially be able to be safely deployed within this population.

Evaluation of intraoperative bleeding in shoulder arthroscopy with preoperative injection of epinephrine saline: a retrospective comparative study

BACKGROUND

Several studies report the positive effects of epinephrine saline irrigation in shoulder arthroscopy^{3,4,15,18,22,23}. Cardiovascular adverse effects have been described^{1,2,5,6,7,9,19}. The Wide Awake Local Anesthesia No Tourniquet (WALANT) limits bleeding^13,16,24,25. The aim of this study is to evaluate the effects of epinephrine saline infiltrations of the shoulder on arthroscopic visual comfort.

METHOD

We carried out a retrospective comparative study composed of 2 groups. We included all patients admitted to the department for a rotator cuff surgery. Our exclusion criteria were any other surgical indication and patient refusal. The protocol consisted in making 3 preoperative shoulder infiltrations of 20 ml of epinephrine saline at 0.005 mg/mL. Injections were performed in all patients in group 1 and no specific treatment was performed in group 2 (control group). Data collection was performed the same way in both groups. The main judgment criterion was the evaluation of the surgeon's overall visual comfort using the Visual Analogue Scale (VAS) at the end of the procedure. We also evaluated the intraoperative discomfort related to bleeding every 15 minutes by an objective scale (the Visual Numeric Rating Scale VNRS), as well as the cumulative bleeding time, operating time, the quantity of irrigation fluid used, the blood pressure at the times of the bleeding, the mean blood pressure during the surgery and the presence of thromboembolic and cardiovascular adverse events.

RESULTS

We included 30 patients in group 1 and 30 patients in the control group. The mean VAS value at the end of the intervention is significantly higher in group 1 than in the control group: VAS = 10 in group 1 versus VAS = 5 in group 2 (p<0.0001) (higher is better). We also observed a significant decrease in VNRS between the two groups: VNRS = 0.25 in group 1 versus VNRS = 1,00 in group 2 (p<0.0001) (lower is better). Bleeding time was significantly lower in patients in group 1 (1min 39s) compared to patients in group 2 (9min 57s) (p<0.0001). No significant difference was demonstrated concerning the operating times, the quantity of irrigation fluid used and the blood pressure data of the two groups. No adverse effects were observed.

CONCLUSION

The infiltration of low doses of adrenaline as performed in WALANT procedures seems effective in improving visualization in arthroscopy by reducing the bleeding. It can be a simple, efficient, and cost-effective technique with no iatrogenic risk to improve the surgeon's comfort in arthroscopic procedures.

Four Questions Nurses Can Ask to Predict PTSD 1 Year After a Motor Vehicle Crash

BACKGROUND

The role of nurses in screening for posttraumatic stress disorder is crucial in trauma units.

OBJECTIVES

To create and evaluate an easy and brief tool for nurses to predict chronic posttraumatic stress disorder 1 year after a motor vehicle crash.

METHODS

We performed a 1-year follow-up multicenter study from 2007 to 2015, including 274 patients injured in a motor vehicle crash who were hospitalized in an orthopedic trauma unit. Nurses administered the DEPITAC questionnaire. Posttraumatic stress disorder was measured by the Post-Traumatic Stress Disorder Checklist of symptoms during the first year following the crash. A multivariable logistic regression model was implemented to select items significantly associated with posttraumatic stress disorder to improve the DEPITAC questionnaire. Predictive performance to predict posttraumatic stress disorder 1 year after the motor vehicle crash was examined for these different models.

RESULTS

Of 274 patients studied, a total of 75.9% completed the questionnaire at 1 year of follow-up. We found that only two questions and two simple elements of the patient's medical record (other injury or a person dying during the crash, perception of vital threat, number of children, and length of stay in trauma) predicted posttraumatic stress disorder 1 year after a motor vehicle crash.

CONCLUSIONS

The brevity of this evaluation, simple scoring rules, and screening test performance suggest that this new screening tool can be easily administered in the acute care setting by nurses.

WALANT technique versus locoregional anesthesia in the surgical management of metacarpal and phalangeal fractures: Lessons from the Covid-19 crisis

Wide Awake Local Anesthesia No Tourniquet (WALANT) is an anesthetic method which uses a local injection of anesthetic and epinephrine, avoiding use of a tourniquet. During the COVID-19 pandemic, human and logistic resources had to be reorganized, and WALANT ensured resilience in our department to maintain access to surgical care. The objective of the present study was to compare hand function recovery 3 months after surgery for unstable metacarpal or phalangeal fracture under regional anesthesia versus WALANT. From November 2020 to May 2021, 36 patients presenting a metacarpal or phalangeal fracture requiring surgical treatment were included in a single-center study in a university hospital center. Nineteen patients underwent surgery under locoregional anesthesia with tourniquet, and 17 under WALANT. The main endpoint was functional recovery at 3 months on QuickDASH score. Need for complementary anesthesia, surgery duration, analgesic consumption, reintervention rate, and patient satisfaction were also assessed. There was no significant difference between groups in functional recovery at 3 months or on the secondary endpoints. In the COVID-19 context, WALANT proved to be a safe and effective method in hand fracture surgery, ensuring access to surgical care. It should be included in surgical training to optimize day-to-day surgical care and face future crises.

Noise rejection through an improved quantum illumination protocol

Quantum illumination protocols can be implemented to improve imaging performance in the low photon flux regime even in the presence of both background light and sensor noise. However, the extent to which this noise can be rejected is limited by the rate of accidental correlations resulting from the detection of photon or noise events that are not quantum-correlated. Here we present an improved protocol that rejects up to [Formula: see text] of background light and sensor noise in the low photon flux regime, improving upon our previous results by an order of magnitude. This improvement, which requires no information regarding the scene or noise statistics, will enable extremely low light quantum imaging techniques to be applied in environments previously thought difficult and be an important addition to the development of covert imaging, quantum microscopes, and quantum LIDAR.

Jones type fifth metatarsal fracture fixation in athletes: A review and current concept

Jones type fifth metatarsal fracture is a common occurrence among athletes at all levels. These fractures may occur due to several mechanisms, but inversions and twisting injuries are considered some of the leading causes in sports. However, while Jones fracture incidences are frequent in the sporting world, there is still a lack of consensus on how such fractures should be effectively managed. There are numerous treatment options for patients with fifth metatarsal Jones fractures. The role of nonoperative treatment remains controversial, with concerns about delayed union and nonunion. Surgical stabilization of metatarsal Jones fractures is therefore often recommended for athletes, as it is often associated with a low number of complications and a higher rate of union than nonoperative management. This review will focus on literature regarding the prevalence of Jones type fifth metatarsal fracture, alongside the efficacy of both conservative and surgical treatment within this population.

Benefits of WALANT in palliative upper limb surgery after nerve injury

Wide-Awake Local Anesthesia No Tourniquet (WALANT) may be a satisfactory anesthesia alternative for the management of upper limb peripheral nerve palsy sequelae. The main advantages are the possibility of active patient cooperation through intraoperative active mobilization, comfort and cost reduction. The legislation about WALANT in France remains unclear; the modalities of lidocaine epinephrine injection should be redefined. For palliative upper limb surgery, WALANT allows the surgeon to adjust the tension on the tendon transfer intraoperatively. Level 1 studies are needed to evaluate the effectiveness of WALANT relative to standard anesthesia techniques (regional/general anesthesia).

Mixed Reality Assisted Percutaneous Scaphoid Fixation: A Proposed New Surgical Technique

The success of percutaneous fixation of non or minimally displaced scaphoid waist fractures is reliant on optimal placement of the screw. This can be challenging for surgeons to achieve, potentially involving a large volume of intraoperative imaging, and surgical time. Mixed reality (MR) is a new technology that allows the projection of holographic imagery within the surgeon's field of vision intraoperatively. This imagery can include surgical planning data and 3D reconstructions of a patient's anatomy that can be used in order to aid the surgeon in achieving accuracy. We describe a technique for how this novel technology might be used in the future to fix scaphoid fractures-MR assisted percutaneous scaphoid fixation. This is done using cadaveric modeling. MR assisted percutaneous scaphoid fixation may have the potential to aid surgeons in achieving an optimal guidewire placement with the ability to reduce surgical time and radiation exposure.

The Glenoid Vault Outer Cortex a new more accurate radiological reference for shoulder arthroplasty

Introduction: Correct positioning of the glenoid component is an important determinant of outcome in shoulder arthroplasty. We describe and assess a new radiological plane of reference for improving the accuracy of glenoid preparation prior to component implantation – the Glenoid Vault Outer Cortex (GvOC) plane. Methods: One hundred and five CT scans of normal scapulae were obtained. Forty six females and 59 males aged between 22 and 30 years. The accuracy of the GvOC plane was then compared against the current “gold standard” – the scapular border (SB). Measurements of glenoid inclination, version, rotation, and offset were obtained using both the GvOC and SB planes. These were then compared to actual values. Results: The mean difference between version obtained using the GvOC plane and the actual value was 1.8° (−2 to 5, SD 1.6) as compared to 6.7° (−2 to 17, SD 4.3) when the SB plane was used, (p < 0.001). The mean difference between estimates of inclination obtained using the GvOC plane and the actual were 1.9° (−4 to 6, SD 1.6) as compared to 11.2° (−4 to 25, SD 6.1) when the SB plane was used, (p < 0.001). Conclusions: The GvOC plane produced estimates of glenoid version and inclination closer to actual values with lower variance than when the SB plane was used. The GvOC may be a more accurate and reproducible radiological method for surgeons to use when defining glenoid anatomy prior to arthroplasty surgery.

Applying the WALANT technique to surgical treatment of distal radius fractures

The Wide-Awake Local Anesthesia No Tourniquet (WALANT) method is a recent anesthesia option for surgery of the upper limbs based on the injection of an anesthetic solution containing adrenaline at the surgical site, hence circumventing tourniquet use. In a prospective study, we compared the functional outcomes using this anesthesia technique with those of the regional anesthesia (RA) technique for the surgical care of distal radius fractures (DRF). From November 2019 to June 2020, a non-randomized, single-center study was conducted with a cohort of 41 patients suffering from a DRF and who received volar plate fixation at a university hospital center. Twenty-one patients had WALANT surgery and 20 had RA with installation of a tourniquet. Over a period of 7 months, the clinical and radiological outcomes as well as the QuickDASH functional score were evaluated. Recovery of wrist function return to work, and analgesic withdrawal for the WALANT group occurred earlier than for the RA group. No noticeable differences were found regarding surgery duration or radiographic results. Using WALANT, functional wrist recovery occurs earlier than with RA. In our study, earlier analgesic stoppage, a quicker return to work and resumption of activity were observed with WALANT. As such, it should become part of the therapeutic arsenal for surgical treatment of DRF.

Characterization and mitigation of fragmentation enzyme-induced dual stranded artifacts

High-throughput short-read sequencing relies on fragmented DNA for optimal sampling of input nucleic acid. Several vendors now offer proprietary enzyme cocktails as a cheaper and more streamlined method of fragmentation when compared to acoustic shearing. We have discovered that these enzymes induce the formation of library molecules containing regions of nearby DNA from opposite strands. Sequencing reads derived from these molecules can lead to artifact-derived variant calls appearing at variant allele frequencies <5%. We present Fragmentation Artifact Detection and Elimination (FADE), software to remove these artifacts from mapped reads and mitigate artifact-related effects on downstream analysis. We find that the artifacts principally affect downstream analyses that are sensitive to a 1-3% artifact bias in the sequencing reads, such as targeted resequencing and rare variant discovery.

Impact of scapular notching on glenoid fixation in reverse total shoulder arthroplasty: an in vitro and finite element study

BACKGROUND

The high incidence of scapular notching in reverse total shoulder arthroplasty (RTSA) has spurred several methods to minimize bone loss. However, up to 93% of RTSAs accompanying scapular notching have been reported to maintain good implant stability for over 10 years. This study was conducted to investigate the relationship between scapular notching and glenoid fixation in RTSA.

METHODS

Cadaveric testing was performed to measure the notch-induced variations in strain on the scapular surface and micromotion at the bone-prosthesis interface during arm abductions of 30°, 60°, and 90°. Finite element analysis was used to further study the bone and screw stresses as well as the bone-prosthesis micromotion in cases with a grade 4 notch during complicated arm motions.

RESULTS

The notch resulted in an apparent increase in inferior screw stress in the root of the screw cap and at the notch-screw conjunction. However, the maximum stress (172 MPa) along the screw after notching is still much less than the fatigue strength of the titanium screw (600 MPa) under cyclic loading. The bone-prosthesis micromotion results did not present significant notch-induced variations.

CONCLUSIONS

Scapular notching will lead to few impacts on the stability of an RTSA on the glenoid side. This finding may explain the long-term longevity of RTSA in cases of severe scapular notching. The relationship between scapular notching and weak regions along the inferior screw may explain why fractures of the inferior screw are sometimes reported in patients with RTSA clinically.

Effect of stress-shielding-induced bone resorption on glenoid loosening in reverse total shoulder arthroplasty

Aseptic loosening of the glenoid component is one of the main reasons for the high revision rates of reverse total shoulder arthroplasty (RTSA). It has been reported that the bulky implant designs may lead to stress shielding. However, it is uncertain whether the shielding effect is severe enough to lead to bone resorption and glenoid loosening. The purpose of this study was to evaluate the level of stress-shielding and assess whether bone resorption plays a role in aseptic glenoid loosening following RTSA. A cadaveric in vitro test model was used to validate a finite element model (FEM) of the scapula. The FEM of the scapula, incorporating adaptive bone remodeling algorithms, was used to predict changes in postoperative bone density after RTSA. Changes in bone strength after implantation were also analyzed. The strain values predicted from the FEM of the scapula were in agreement with the in vitro measurements. Analysis of postoperative bone adaptation revealed that strain-induced bone resorption began at the peg of the implant and around the resected bone surface and then gradually expended to the peripheral regions. The bone strength also reduced postoperatively and appeared particularly around the implant peg. Strain-induced bone resorption is a likely source of the bone loss commonly observed in RTSA. The finite element glenoid bone remodeling simulation may be used as a tool to evaluate glenoid implant design.

Imaging through noise with quantum illumination

The contrast of an image can be degraded by the presence of background light and sensor noise. To overcome this degradation, quantum illumination protocols have been theorized that exploit the spatial correlations between photon pairs. Here, we demonstrate the first full-field imaging system using quantum illumination by an enhanced detection protocol. With our current technology, we achieve a rejection of background and stray light of up to 5.8 and also report an image contrast improvement up to a factor of 11, which is resilient to both environmental noise and transmission losses. The quantum illumination protocol differs from usual quantum schemes in that the advantage is maintained even in the presence of noise and loss. Our approach may enable laboratory-based quantum imaging to be applied to real-world applications where the suppression of background light and noise is important, such as imaging under low photon flux and quantum LIDAR.

Imaging Bell-type nonlocal behavior

The violation of a Bell inequality not only attests to the nonclassical nature of a system but also holds a very unique status within the quantum world. The amount by which the inequality is violated often provides a good benchmark on how a quantum protocol will perform. Acquiring images of such a fundamental quantum effect is a demonstration that images can capture and exploit the essence of the quantum world. Here, we report an experiment demonstrating the violation of a Bell inequality within observed images. It is based on acquiring full-field coincidence images of a phase object probed by photons from an entangled pair source. The image exhibits a violation of a Bell inequality with S = 2.44 ± 0.04. This result both opens the way to new quantum imaging schemes based on the violation of a Bell inequality and suggests promise for quantum information schemes based on spatial variables.

The Role of Pharmacists in Safe Opioid Dispensing

Opioid misuse, abuse, and diversion continues to be a public health issue. Pharmacists (particularly those who work in the community setting) form the vanguard of health-care providers facing the opioid crisis because they have the opportunity to interact with patients more frequently than primary care or specialty medical providers. These frequent interactions give pharmacists more opportunities to properly counsel patients on prevention and to reinforce appropriate use of opioid medications. Pharmacists should be aware of the strategies for reducing opioid misuse, abuse, and diversion, including understanding mandates on prescription limitations; knowing how to use prescription drug monitoring programs; knowing when drug take-back programs are occurring; educating patients on the risks of opioid abuse, safe storage, and proper disposal of unused medications; identifying "red flag" behavior that may indicate opioid misuse; using assessments that help identify a patient's risk for opioid abuse; interacting with other health-care professionals to discuss a patient's care; understanding how abuse-deterrent opioids work and their limitations; preparing for opioid overdose management and understanding the local regulations on naloxone availability; and knowing when to refer patients to addiction services. Using these strategies, pharmacists have an opportunity to potentially reduce opioid abuse and improve patient outcomes.

Effect of baseplate positioning on fixation of reverse total shoulder arthroplasty

BACKGROUND

The glenoid component in reverse total shoulder arthroplasty is recommended to be positioned inferiorly or with a downward tilt with the intention of reducing scapular notching. However, it is still unclear whether modifying the position of the glenoid prosthesis affects implant stability. The aim of this study was to determine the association between implant positioning and glenoid prosthesis fixation using Grammont reverse total shoulder arthroplasty.

METHODS

Four positions for the glenoid prosthesis were studied using the finite element method. The glenosphere was positioned as follows: 1) in the middle of the glenoid fossa, 2) flush with the inferior glenoid rim, 3) with an inferior overhang, 4) with a 15° inferior inclination. Bone-prosthesis micromotions and strain-induced bone adaptations were quantified during five daily activities.

FINDINGS

When the glenoid component was tilted inferiorly, the activities producing anterior-posterior shear forces (e.g. standing up from an armchair) caused an increase in peak micromotions. In the lateral-middle glenoid, inferior positioning caused a 64.6% reduction in bone apparent density. In the lateral-inferior glenoid, central positioning led to the most severe bone resorption, reaching 43.9%.

INTERPRETATION

Reducing activities which generate anterior-posterior shear forces on the shoulder joint will increase bone formation and may improve the primary stability of the implant when fixed in the position with an inferior tilt. Postoperative bone resorption is highly dependent on implant positioning. Understanding the relationship between bone resorption and implant positioning will help surgeons improve the long-term stability of reverse total shoulder arthroplasty.

Experimental Limits of Ghost Diffraction: Popper's Thought Experiment

Quantum ghost diffraction harnesses quantum correlations to record diffraction or interference features using photons that have never interacted with the diffractive element. By designing an optical system in which the diffraction pattern can be produced by double slits of variable width either through a conventional diffraction scheme or a ghost diffraction scheme, we can explore the transition between the case where ghost diffraction behaves as conventional diffraction and the case where it does not. For conventional diffraction the angular extent increases as the scale of the diffracting object is reduced. By contrast, we show that no matter how small the scale of the diffracting object, the angular extent of the ghost diffraction is limited (by the transverse extent of the spatial correlations between beams). Our study is an experimental realisation of Popper’s thought experiment on the validity of the Copenhagen interpretation of quantum mechanics. We discuss the implication of our results in this context and explain that it is compatible with, but not proof of, the Copenhagen interpretation.

Cadaveric study validating in vitro monitoring techniques to measure the failure mechanism of glenoid implants against clinical CT

Definite glenoid implant loosening is identifiable on radiographs, however, identifying early loosening still eludes clinicians. Methods to monitor glenoid loosening in vitro have not been validated to clinical imaging. This study investigates the correlation between in vitro measures and CT images. Ten cadaveric scapulae were implanted with a pegged glenoid implant and fatigue tested to failure. Each scapulae were cyclically loaded superiorly and CT scanned every 20,000 cycles until failure to monitor progressive radiolucent lines. Superior and inferior rim displacements were also measured. A finite element (FE) model of one scapula was used to analyze the interfacial stresses at the implant/cement and cement/bone interfaces. All ten implants failed inferiorly at the implant-cement interface, two also failed at the cement-bone interface inferiorly, and three showed superior failure. Failure occurred at of 80,966 ± 53,729 (mean ± SD) cycles. CT scans confirmed failure of the fixation, and in most cases, was observed either before or with visual failure. Significant correlations were found between inferior rim displacement, vertical head displacement and failure of the glenoid implant. The FE model showed peak tensile stresses inferiorly and high compressive stresses superiorly, corroborating experimental findings. In vitro monitoring methods correlated to failure progression in clinical CT images possibly indicating its capacity to detect loosening earlier for earlier clinical intervention if needed. Its use in detecting failure non-destructively for implant development and testing is also valuable. The study highlights failure at the implant-cement interface and early signs of failure are identifiable in CT images. © 2018 The Authors. Journal of Orthopaedic Research® Published by Wiley Periodicals, Inc. on behalf of the Orthopaedic Research Society. J Orthop Res 36:2524-2532, 2018.

Resolution limits of quantum ghost imaging

Quantum ghost imaging uses photon pairs produced from parametric downconversion to enable an alternative method of image acquisition. Information from either one of the photons does not yield an image, but an image can be obtained by harnessing the correlations between them. Here we present an examination of the resolution limits of such ghost imaging systems. In both conventional imaging and quantum ghost imaging the resolution of the image is limited by the point-spread function of the optics associated with the spatially resolving detector. However, whereas in conventional imaging systems the resolution is limited only by this point spread function, in ghost imaging we show that the resolution can be further degraded by reducing the strength of the spatial correlations inherent in the downconversion process.

Structural colour from helicoidal cell-wall architecture in fruits of Margaritaria nobilis

The bright and intense blue-green coloration of the fruits of Margaritaria nobilis (Phyllanthaceae) was investigated using polarization-resolved spectroscopy and transmission electron microscopy. Optical measurements of freshly collected fruits revealed a strong circularly polarized reflection of the fruit that originates from a cellulose helicoidal cell wall structure in the pericarp cells. Hyperspectral microscopy was used to capture the iridescent effect at the single-cell level.

Dynamic Three-Dimensional Shoulder Mri during Active Motion for Investigation of Rotator Cuff Diseases

Background

MRI is the standard methodology in diagnosis of rotator cuff diseases. However, many patients continue to have pain despite treatment, and MRI of a static unloaded shoulder seems insufficient for best diagnosis and treatment. This study evaluated if Dynamic MRI provides novel kinematic data that can be used to improve the understanding, diagnosis and best treatment of rotator cuff diseases.

Methods

Dynamic MRI provided real-time 3D image series and was used to measure changes in the width of subacromial space, superior-inferior translation and anterior-posterior translation of the humeral head relative to the glenoid during active abduction. These measures were investigated for consistency with the rotator cuff diseases classifications from standard MRI.

Results

The study included: 4 shoulders with massive rotator cuff tears, 5 shoulders with an isolated full-thickness supraspinatus tear, 5 shoulders with tendinopathy and 6 normal shoulders. A change in the width of subacromial space greater than 4mm differentiated between rotator cuff diseases with tendon tears (massive cuff tears and supraspinatus tear) and without tears (tendinopathy) (p = 0.012). The range of the superior-inferior translation was higher in the massive cuff tears group (6.4mm) than in normals (3.4mm) (p = 0.02). The range of the anterior-posterior translation was higher in the massive cuff tears (9.2 mm) and supraspinatus tear (9.3 mm) shoulders compared to normals (3.5mm) and tendinopathy (4.8mm) shoulders (p = 0.05).

Conclusion

The Dynamic MRI enabled a novel measure; ‘Looseness’, i.e. the translation of the humeral head on the glenoid during an abduction cycle. Looseness was better able at differentiating different forms of rotator cuff disease than a simple static measure of relative glenohumeral position.

Quantification of clearance and creep in acetabular wear measurements

BACKGROUND

This study aimed to measure femoral head penetration before occurrence of real wear, and to quantify the portions attributable respectively to clearance and plastic deformations in various acetabular designs.

METHODS

We analyzed CT scans from 15 patients at 'day five' after total hip arthroplasty (THA). All patients received Exafit(®) femoral stems and 28 mm heads: 5 patients had cemented Durasul(®) all-PE cups, 5 patients had un-cemented Allofit(®) metal-backed cups, and 5 patients had un-cemented Stafit(®) dual-mobility cups. We also analyzed CT scans of samples of the three head-cup combinations to compare in vivo and in vitro measurements.

RESULTS

The mean femoral head penetration measured on 'day five' was lower for all-PE cups (0.196 mm) than for metal-backed cups (0.551 mm) and dual-mobility cups (0.634 mm).

CONCLUSIONS

The present study indicates that isolated measurements of femoral head penetration include 0.15-0.46 mm of radial clearance and 0.05-0.27 mm of creep, and confirms that the majority of so-called bedding-in observed in the first post-operative months is not entirely due to wear.

Confession of a Magnesium Battery

Magnesium is an ideal metal anode that has nearly double the volumetric capacity of lithium metal with a very negative reduction potential of -2.37 vs SHE. A significant advantage of magnesium is the apparent lack of dendrite formation during charging, which overcomes major safety and performance challenges encountered with using lithium metal anodes. Here, we highlight major recent advances in nonaqueous Mg electrochemistry, notably the development of electrolytes and cathodes, and discuss some of the challenges that must be overcome to realize a practical magnesium battery.

Endoluminal minimally invasive surgery for chronic exertional compartment syndrome: a new technique

INTRODUCTION

Fasciotomy is the usual treatment for chronic exertional compartment syndrome of the lower limb. For esthetic reasons, minimally invasive techniques have been developed but can generate complications. Herein, we report the use of the KnifeLight during minimally invasive anterior and lateral compartment release in view of reducing these complications, within a feasibility study.

MATERIAL AND METHODS

This study was conducted on four cadavers (eight legs) and then an athletic patient (two legs).

RESULTS

The technique was carried out on all cases with no complications. The patient's result was excellent.

DISCUSSION

The KnifeLight can be used to perform a fasciotomy of the leg's anterior and lateral compartments. It seems to provide the operator with additional safety compared to other minimally invasive techniques.

CONCLUSION

This is a simple, reliable, and reproducible technique that deserves to be better known.

A CT scan protocol for the detection of radiographic loosening of the glenoid component after total shoulder arthroplasty

BACKGROUND AND PURPOSE

It is difficult to evaluate glenoid component periprosthetic radiolucencies in total shoulder arthroplasties (TSAs) using plain radiographs. This study was performed to evaluate whether computed tomography (CT) using a specific patient position in the CT scanner provides a better method for assessing radiolucencies in TSA.

METHODS

Following TSA, 11 patients were CT scanned in a lateral decubitus position with maximum forward flexion, which aligns the glenoid orientation with the axis of the CT scanner. Follow-up CT scanning is part of our routine patient care. Glenoid component periprosthetic lucency was assessed according to the Molé score and it was compared to routine plain radiographs by 5 observers.

RESULTS

The protocol almost completely eliminated metal artifacts in the CT images and allowed accurate assessment of periprosthetic lucency of the glenoid fixation. Positioning of the patient within the CT scanner as described was possible for all 11 patients. A radiolucent line was identified in 54 of the 55 observed CT scans and osteolysis was identified in 25 observations. The average radiolucent line Molé score was 3.4 (SD 2.7) points with plain radiographs and 9.5 (SD 0.8) points with CT scans (p = 0.001). The mean intra-observer variance was lower in the CT scan group than in the plain radiograph group (p = 0.001).

INTERPRETATION

The CT scan protocol we used is of clinical value in routine assessment of glenoid periprosthetic lucency after TSA. The technique improves the ability to detect and monitor radiolucent lines and, therefore, possibly implant loosening also.

Fibular nonunion after closed-wedge high tibial osteotomy

Closed-wedge valgus high tibial osteotomy (HTO) has been reported to be an effective procedure for the treatment of medial compartment osteoarthritis of the knee. It requires shortening the fibula, for which many techniques have been described. Dislocation of the proximal tibiofibular joint limits the correction angle of the procedure and the osteotomy of the fibular head runs the rare but dramatic risk of common fibular nerve palsy, which is why many surgeons perform the osteotomy more distally at the shaft. However, the potential complications of fibula shaft osteotomy in closed-wedge proximal tibial osteotomy have been poorly reported. The purpose of this study is to accurately define the incidence and risk of fibular complications.

MATERIALS AND METHODS

One hundred and eight patients (59 men, 49 women, 53±10years old, preoperative varus: 6.7°±4°) underwent a closed-wedge HTO with fibular shaft osteotomy between 1999 and 2004. They were followed up prospectively for clinical and radiological evaluation (2years of follow-up). The main evaluation criterion was the presence of fibular nonunion.

RESULTS

Eighteen knees (16.6%) underwent fibular complications: 15 nonunions were indexed (13.9%); 11 of them (10.1%) required surgical revision. Three knees had nerve injury, with spontaneous recovery for two of them.

DISCUSSION

Fibular nonunion is the most frequent complication, which often leads to revision procedures. Nonunion was correlated to the preoperative body mass index, the obliquity of the osteotomy plane, and the fragmentary contact. No nonunion was reported when the obliquity of the osteotomy plane was above 50° or the fragment contact greater than 50%.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Total shoulder arthroplasty does not correct the orientation of the eroded glenoid

BACKGROUND AND PURPOSE

Alignment of the glenoid component with the scapula during total shoulder arthroplasty (TSA) is challenging due to glenoid erosion and lack of both bone stock and guiding landmarks. We determined the extent to which the implant position is governed by the preoperative erosion of the glenoid. Also, we investigated whether excessive erosion of the glenoid is associated with perforation of the glenoid vault.

METHODS

We used preoperative and postoperative CT scans of 29 TSAs to assess version, inclination, rotation, and offset of the glenoid relative to the scapula plane. The position of the implant keel within the glenoid vault was classified into three types: centrally positioned, component touching vault cortex, and perforation of the cortex.

RESULTS

Preoperative glenoid erosion was statistically significantly linked to the postoperative placement of the implant regarding all position parameters. Retroversion of the eroded glenoid was on average 10° (SD10) and retroversion of the implant after surgery was 7° (SD11). The implant keel was centered within the vault in 7 of 29 patients and the glenoid vault was perforated in 5 patients. Anterior cortex perforation was most frequent and was associated with severe preoperative posterior erosion, causing implant retroversion.

INTERPRETATION

The position of the glenoid component reflected the preoperative erosion and "correction" was not a characteristic of the reconstructive surgery. Severe erosion appears to be linked to vault perforation. If malalignment and perforation are associated with loosening, our results suggest reorientation of the implant relative to the eroded surface.