Volar Locking Plating of Extra-articular Distal Radius Fracture: A Retrospective Clinical Study Comparing Locking Screws versus Smooth Locking Pegs

Background  Open reduction and internal fixation of distal radius fractures is one of the most common procedures performed in wrist surgery. The use of volar locking plate has gained increasing interest in the past decade. Epiphyseal fixation can be done either with locking screws or smooth locking pegs, with no evidence supporting the use of one rather than the other. Purpose  The aim of this study is to compare the stability of distal radius fixation by volar locking plate using locking screws or smooth locking pegs. Methods  Adult patients with A2-A3 AO fractures treated with a volar plate with locking screws only or smooth locking pegs only were retrospectively included. Radiographic assessment was performed to evaluate extra-articular parameters in the intraoperative postreduction and fixation period and after bony healing. Forty-seven distal radius fractures were included. Results  Twenty-four fractures had fixation with locking screws and 23 had fixation with smooth locking pegs. For both groups, all radiographic parameters measured showed a statistically significant difference between the intraoperative postreduction and fixation period and the remote postoperative period after union of the fracture ( p  < 0.05) attesting a slight loss of reduction. Nevertheless, there were no significant differences between the groups in radiographic extra-articular parameters. Conclusion  This clinical study shows that there is no difference in stability fixation between locking screws or smooth locking pegs in A2-A3 distal radius fractures. Clinical Relevance  The use of smooth locking pegs only for epiphyseal fixation appears to be safe in volar plating of A2-A3 distal radius fractures in adult patients and could be an alternative to locking screws. More clinical data are needed to confirm these results. Level of Evidence  Level III; retrospective comparative study.

A novel pulsed electromagnetic field device as an adjunct therapy to surgical treatment of distal radius fractures: a prospective, double-blind, sham-controlled, randomized pilot study

INTRODUCTION

The purpose of this study is to evaluate whether using a Fracture Healing Patch (FHP) device that generates pulsed electromagnetic fields (PEMF), applied at the fracture site immediately after open reduction and internal fixation surgery, can accelerate healing of acute distal radius fractures.

METHODS

In a prospective, double-blind, randomized, and sham-controlled study, thirty-two patients with DRFs treated with ORIF were included. Patients were allocated to a PEMF (active) group (n = 15) or a control (sham) group (n = 17). All patients were assessed with regard to functional Patient-Rated Wrist Evaluation (PRWE), SF12, and radiological union outcomes (X-rays and computed tomography (CT) scans) at 2, 4, 6, and 12 weeks postoperatively.

RESULTS

Patients treated with the FHP demonstrated significantly bone bridging at 4 weeks as assessed by CT (70% vs 54%, p = 0.05). Mean grip strength in the active group was significantly higher as compared to control (16 ± 9 kg vs 7 ± 3.5 kg, respectively, p = 0. 02). The function subscale of the PRWE was significantly better in PEMF-treated group at 6 weeks after surgery (27.2 VS 35.5, p = 0.04). No statistically significant differences were found in SF12.

CONCLUSION

PEMF application after ORIF of DRFs is safe, may accelerate bone healing which could lead to an earlier return to daily life activities and work.

LEVEL OF EVIDENCE

I.

Conserved allosteric inhibition mechanism in SLC1 transporters

Excitatory amino acid transporter 1 (EAAT1) is a glutamate transporter belonging to the SLC1 family of solute carriers. It plays a key role in the regulation of the extracellular glutamate concentration in the mammalian brain. The structure of EAAT1 was determined in complex with UCPH-101, apotent, non-competitive inhibitor of EAAT1. Alanine serine cysteine transporter 2 (ASCT2) is a neutral amino acid transporter, which regulates pools of amino acids such as glutamine between intracellular and extracellular compartments . ASCT2 also belongs to the SLC1 family and shares 58% sequence similarity with EAAT1. However, allosteric modulation of ASCT2 via non-competitive inhibitors is unknown. Here, we explore the UCPH-101 inhibitory mechanisms of EAAT1 and ASCT2 by using rapid kinetic experiments. Our results show that UCPH-101 slows substrate translocation rather than substrate or Na+ binding, confirming a non-competitive inhibitory mechanism, but only partially inhibits wild-type ASCT2. Guided by computational modeling using ligand docking and molecular dynamics simulations, we selected two residues involved in UCPH-101/EAAT1 interaction, which were mutated in ASCT2 (F136Y, I237M, F136Y/I237M) in the corresponding positions. We show that in the F136Y/I237M double-mutant transporter, 100% of the inhibitory effect of UCPH-101 could be restored, and the apparent affinity was increased (Ki = 4.3 μM), much closer to the EAAT1 value of 0.6 μM. Finally, we identify a novel non-competitive ASCT2 inhibitor, through virtual screening and experimental testing against the allosteric site, further supporting its localization. Together, these data indicate that the mechanism of allosteric modulation is conserved between EAAT1 and ASCT2. Due to the difference in binding site residues between ASCT2 and EAAT1, these results raise the possibility that more potent, and potentially selective ASCT2 allosteric inhibitors can be designed .

The Effects of Novel Pulsed Electromagnetic Field Therapy Device on Acute Distal Radius Fractures: A Prospective, Double-Blind, Sham-Controlled, Randomized Pilot Study

BACKGROUND

this pilot study aimed at determining whether the application of a novel new method of generating pulsed electromagnetic field (PEMF), the Fracture Healing Patch (FHP), accelerates the healing of acute distal radius fractures (DRF) when compared to a sham treatment.

METHODS

41 patients with DRFs treated with cast immobilization were included. Patients were allocated to a PEMF group (n = 20) or a control (sham) group (n = 21). All patients were assessed with regard to functional and radiological outcomes (X-rays and CT scans) at 2, 4, 6 and 12 weeks.

RESULTS

fractures treated with active PEMF demonstrated significantly higher extent of union at 4 weeks as assessed by CT (76% vs. 58%, p = 0.02). SF12 mean physical score was significantly higher in PEMF treated group (47 vs. 36, p = 0.005). Time to cast removal was significantly shorter in PEMF treated patients, 33 ± 5.9 days in PEMF vs. 39.8 ± 7.4 days in sham group (p = 0.002).

CONCLUSION

early addition of PEMF treatment may accelerate bone healing which could lead to a shorter cast immobilization, thus allowing an earlier return to daily life activities and work. There were no complications related to the PEMF device (FHP).

Rethinking Conservative Treatment of Humeral Diaphyseal Fractures in Elderly Patients With Dementia

OBJECTIVES

To assess outcomes and complications of conservatively managed humeral diaphyseal fractures in elderly patients, with an emphasis on the subgroup diagnosed with dementia.

DESIGN

Retrospective.

SETTING

Upper extremity surgery unit at an academic Level I trauma center.

PATIENTS/PARTICIPANTS

Consecutive patients 65 years of age and older who were managed conservatively for humeral diaphyseal fractures between 2007 and 2015.

INTERVENTION

Conservatively managed humeral diaphyseal fractures.

MAIN OUTCOME MEASUREMENTS

Complications and radiographic outcomes.

RESULTS

One-hundred twenty-four patients who were conservatively managed for humeral diaphyseal fractures were identified. Their mean age was 77 (65-92) years, 36 (30%) of them were male and 88 (70%) were female. Fifty-seven (46%) patients experienced complications associated with their treatment, and 33 (27%) patients were eventually treated surgically. Seventeen (14%) patients were diagnosed with dementia. This subgroup had 64% fracture-related complications, and all of them were operated (P-value <0.01 compared with age-matched patients among the other 107 participants in the study).

CONCLUSION

Conservative management of humeral diaphyseal fractures seems to be associated with greater morbidity in elderly patients, especially in those diagnosed with dementia. Therefore, early surgical treatment should be considered.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Early postoperative dressing removal in hand surgery: Novel concepts for individualized surgical dressing management

Postoperative dressing protocols after clean surgery without implant vary widely. The purpose of this study was to elucidate whether early postoperative dressing removal is a valid option, as compared to untouched dressing or twice-weekly dressing change approach. A prospective randomized study was conducted on patients who underwent carpal tunnel release (CTR) or trigger finger release (TFR) between January and November 2020. Patients were randomly distributed into 3 groups: surgical dressing untouched until first follow up (SDU); surgical dressing changed twice a week in a health maintenance organization (HMO); and surgical dressing removed at first postoperative day (SDR). Data collected included patient characteristics, pre-and post-operative functional (QuickDASH) and autonomy (Instrumental Activities of Daily Living performance (IADL)) scores, Vancouver scar scale (VSS) and potential complications. Eighty-four patients were included: 28 (33.3%), 29 (34.5%) and 27 (32.1%) in the SDU, HMO and SDR groups, respectively. Deterioration in mean IADL score at 2-week follow-up was statistically significant in the HMO group (mean delta 3.35, p = 0.008). Quick DASH score improved significantly between preoperative and 2-week follow-up values only in the SDU group (mean delta 9.12, p = 0.012). Other parameters, including wound complications, did not differ significantly between groups. Early removal of postoperative dressing and immediate wound exposure was a safe option after CTR and TFR. An untouched bulky dressing correlated with early functional improvement. Finally, iterative dressing change in HMO showed no benefit and led to significant deterioration in early postoperative autonomy. IRB APPROVAL: 0548-18-TLV. LEVEL OF EVIDENCE: I.

Clinical Outcomes of Limited Open Intramedullary Headless Screw Fixation of Metacarpal Fractures in 91 Consecutive Patients

Background: The objective of the study is to evaluate clinical and radiographic outcomes in patients treated with limited-open retrograde intramedullary headless screw (IMHS) fixation for metacarpal neck and shaft fractures. Methods: Retrospective review of 91 consecutive patients (79 men; 12 women), mean age 28 (range =15-69) years, treated with IMHS fixation for acute displaced metacarpal neck (N = 56) and shaft (N = 35) fractures at a single institution. Mean follow-up was 10 (range = 1-71, median = 3) months. Preoperative mean magnitude of metacarpal neck angulation was 48° (range = 0°-90°), and mean shaft angulation was 42° (range = 0°-70°). Active motion was initiated within 5 days postoperatively. Clinical outcomes were assessed with digital goniometry, grip strength, and return to full activity. The time to radiographic union and radiographic arthrosis was assessed. Results: All 91 patients achieved full functional arc of metacarpophalangeal (MCP) motion, and all achieved full active MCP extension or hyperextension. At mean follow-up of 10 months, postoperative mean MCP joint flexion-extension arc was 88° (range = 55°-110°). Grip strength was available for 52 patients and measured 104.1% of the contralateral hand (range = 58%-230%). Radiographic union data were available for 86 patients. Seventy-six percent (65/86) achieved radiographic union by the end of week 6 (range = 2-10 weeks). Early arthrosis was noted in 1 patient at the MCP. There were 3 cases of shaft refracture after recurrent blunt trauma, following prior evidence of full osseous union. Conclusions: The IMHS fixation is safe, reliable, and durable for metacarpal neck/subcapital, axially stable shaft fractures, and select delayed unions or malunions. It allows for early postoperative motion without affecting union rates and obviates immobilization. This technique offers distinct advantages over formal open reduction and percutaneous Kirschner wire techniques.

Subspinal impingement: clinical outcomes of arthroscopic decompression with one year minimum follow up

PURPOSE

This study was designed to (1) evaluate the clinical outcomes after arthroscopic subspinal decompression in patients with hip impingement symptoms and low AIIS, and to (2) assess the presence of low anterior inferior iliac spine on the pre-operative radiographs of patients with established subspinal impingement diagnosed intra-operatively.

METHODS

Retrospective analysis of patients who underwent arthroscopic subspinal decompression has been performed. The indications for surgery were femoroacetabular impingement (FAI), or subspinal impingement. Pre-operative radiographs were assessed for anterior inferior iliac spine type. Intra-operative diagnosis of low anterior inferior iliac spine was based on the level of anterior inferior iliac spine extension relative to the acetabulum and the presence of reciprocal labral and chondral lesions. In patients where low anterior inferior iliac spine was not diagnosed on pre-operative radiographs, the pre-operative radiographs were re-read retrospectively to assess missed signs of low anterior inferior iliac spine.

RESULTS

Thirty-four patients underwent arthroscopic subspinal decompression between 2012 and 2015. The patients were followed for a median of 25 months (13-37 months). Intra-operatively, grade 2 anterior inferior iliac spine was found in 27 patients and grade 3 anterior inferior iliac spine was found in 7 patients. MHHS, HOS, and HOSS scores increased from median (range) pre-operative scores of 55 (11-90), 48 (20-91) and 20 (0-80) to 95 (27-100), 94 (30-100) and 91 (5-100), respectively (p < 0.0001, p = 0.001, p < 0.0001, respectively). Pre-operative diagnosis of low AIIS was made in 6/34 patients via AP radiographs. On retrospective analysis of pre-operative radiographs, signs of low AIIS were still not observed in 21/34 (61.8%) patients.

CONCLUSIONS

Arthroscopic subspinal decompression of low AIIS yielded significantly improved outcome measures and high patient satisfaction at a minimum of 13 months follow-up. Low AIIS is often under-diagnosed on AP pelvis and lateral frog radiographs and if left untreated, may result in unresolved symptoms and failed procedure.

LEVEL OF EVIDENCE

IV.

Messenger RNA encoding constitutively active Toll-like receptor 4 enhances effector functions of human T cells

Adoptive T cell therapy of cancer employs a large number of ex-vivo-propagated T cells which recognize their targets either by virtue of their endogenous T cell receptor (TCR) or via genetic reprogramming. However, both cell-extrinsic and intrinsic mechanisms often diminish the in-vivo potency of these therapeutic T cells, limiting their clinical efficacy and broader use. Direct activation of human T cells by Toll-like receptor (TLR) ligands induces T cell survival and proliferation, boosts the production of proinflammatory cytokines and augments resistance to regulatory T cell (Treg) suppression. Removal of the TLR ligand-binding region results in constitutive signalling triggered by the remaining cytosolic Toll/interleukin-1 receptor (TIR) domain. The use of such TIR domains therefore offers an ideal means for equipping anti-tumour T cells with the arsenal of functional attributes required for improving current clinical protocols. Here we show that constitutively active (ca)TLR-4 can be expressed efficiently in human T cells using mRNA electroporation. The mere expression of caTLR-4 mRNA in polyclonal CD8 and CD4 T cells induced the production of interferon (IFN)-γ, triggered the surface expression of CD25, CD69 and 4-1BB and up-regulated a panel of cytokines and chemokines. In tumour-infiltrating lymphocytes prepared from melanoma patients, caTLR-4 induced robust IFN-γ secretion in all samples tested. Furthermore, caTLR-4 enhanced the anti-melanoma cytolytic activity of tumour-infiltrating lymphocytes and augmented the secretion of IFN-γ, tumour necrosis factor (TNF)-α and granulocyte-macrophage colony-stimulating factor (GM-CSF) for at least 4 days post-transfection. Our results demonstrate that caTLR-4 is capable of exerting multiple T cell-enhancing effects and can potentially be used as a genetic adjuvant in adoptive cell therapy.

Clinical characteristics of children with 2009 pandemic H1N1 influenza virus infections

BACKGROUND

Further understanding of the clinical manifestations, hospital course and treatment options of the 2009 pandemic H1N1 influenza virus (H1N1) is needed in preparation for future outbreaks.

METHODS

Seventy-three children with polymerase-chain-reaction-confirmed infections with H1N1 treated in a tertiary care medical center in Israel were included in the study. Clinical data were extracted from medical records, and analyzed by hospitalization status or the presence of underlying chronic medical conditions.

RESULTS

Prevalent symptoms were fever, cough and shortness of breath, with additional findings of conjunctivitis, seizures, chills, dizziness, purpuric rash and chest pain. Hospitalized patients were more likely to have shortness of breath (OR 26.7, 95%CI: 3.5-1150), abnormal lung auscultation (OR 11.6, 95%CI: 2.8-67), abnormal X-ray (OR 3.3, 95%CI: 1.1-9.6), and a chronic illness (OR 5.4, 95%CI: 1.8-17), compared with non-hospitalized ones. Disease manifestations were similar between children with or without chronic diseases. Only two (2.7%) children required intensive care, and no deaths were recorded. A high rate (18%) of thrombocytopenia was found. One child had rapid symptom resolution after intravenous immunoglobulin treatment.

CONCLUSION

H1N1 infection follows a mild course, even in the presence of severe underlying diseases. Abnormal respiratory findings and the presence of a chronic disease probably contributed to the decision to hospitalize patients. A rapid resolution of H1N1 symptoms after intravenous immunoglobulin treatment warrants further study, and could be a possible therapeutic option for severe cases.

Role of elastic fibers in cooling-induced relaxation

The objective of this work was to confirm the main role of elastic fibers in differing responses of certain vessels during cooling from 37 to 8 degrees C. Previous results have shown that the nature of the vessel (conduit vessel vs muscular vessel) determines the different behavior (dilatation vs contraction) of isolated vessel segments when temperature decreases from 37 to 8 degrees C. In this work, it has been demonstrated that vessels with a great amount of elastic fibers show a dilatation when cooling. On the other hand, muscular vessels with fewer elastic fibers, such as the renal artery, undergo a contraction. The output of calcium from intracellular stores causes contraction of the renal artery during cooling. In this vessel, vasodilatation occurs only when mechanisms of smooth muscle contraction are inactive, as is the case with vessels that have undergone a cold storage period of 48 h. The results presented in this work confirm that there are two main effects, which directly depend on the vessel origin. In conduit arteries, the decrease of temperature induces a vascular relaxation, dependent on the elastic component of the vessel wall. In muscular vessels, the predominant effect is cooling-induced contraction due to an increase of intracellular calcium. This cooling-induced contraction needs the vessel to be in optimal conditions with an active metabolism of the muscular cells. These results are a crucial issue in the sense of explaining several biomedical mechanisms where hypothermia is implicated. The type of vessel implicated in procedures, such as isolated organ perfusion, extracorporeal circulation, and bypass surgery, must be taken into account.

LC/MS determination of the intracellular concentration of two novel aryl phosphoramidate prodrugs of PMPA and their metabolites in dog PBMC

LC/MS assays were developed to determine the plasma and intracellular concentrations of two aryl phosphoramidate prodrugs of the nucleotide analog 9-[2-R-(phosphonomethoxy)propyl]adenine. LC/MS was used to demonstrate the presence of high concentrations of PMPA in peripheral blood mononucleocytes following oral administration of prodrugs in dogs. High concentrations of PMPA and active metabolite were detected in MT-2 cells incubated with prodrug using an ion-pairing LC/MS assay.

Perfusate lactate dehydrogenase level and intrarenal resistance could not be adequate markers of perfusion quality during isolated kidney perfusion

The main goal of this work was to study the influence of perfusion pressure and flow waveform during kidney perfusion, and the relationship between renal vascular resistance (RVR) and lactate dehydrogenase (LDH) concentration in the perfusate. Simultaneous constant pressure kidney perfusions were performed with either pulsatile or continuous flow at either 30 or 80 mm Hg of constant perfusion pressure. Mean flow, pressure, and RVR were displayed online during perfusion. Perfusate samples for LDH, creatine phosphatase kinase (CPK), and alkaline phosphatase (AP) determinations were taken. At the end of the perfusion, 2 ml of Evans blue was injected into the circuit to obtain images of perfusate distribution, and the kidneys were weighed. Also, hematoxylin/eosine studies were performed, showing more Bowman's space and tubular dilation in kidneys perfused with high pressure. We did not find differences in RVR between kidneys perfused at 30 and 80 mm Hg; nevertheless, perfusate distribution was better in the 80 mm Hg perfusions. We did not find any correlation between enzyme release and RVR in kidneys perfused with different mean pressures. These findings suggest that vascular resistance and LDH concentration cannot be independently considered as adequate markers of perfusate distribution.

Paradoxical effects of temperature on vascular tone

Temperature may have significant influence on vascular tone in such cases as organ preservation, coronary bypass surgery, and extracorporeal circulation. The aim of this research was to study the direct effect of temperature variation on vascular tone in an attempt to elucidate the mechanisms involved. In a first series of experiments, the isometric tension of two different vessels (rat thoracic aorta and pig renal branch artery) was studied at different temperatures. To study the role of calcium in this response, a second series of experiments was performed. In this the vessels were incubated with the intracellular chelator BAPTA/AM. Further experiments were performed to test the effect of cold storage. Our results show that changes in temperature lead to different results in pig renal artery and rat aorta. A decrease in temperature induced a highly reproducible relaxation in rat aorta, whereas pig renal artery presented cooling-induced contraction. Moreover, whereas calcium depletion failed to inhibit cooling-induced relaxation in rat aorta, it did not provoke cooling-induced contraction in pig renal artery. Similar responses were obtained with cold storage and calcium depletion. We intend to demonstrate that, just as the effect of temperature variation on pig renal artery is due to a metabolic mechanism, its effect on rat aorta may be due to structural factors. This hypothesis is supported by the result of histological studies which demonstrate a higher proportion of elastin fibres in rat aorta than in pig renal artery.