Three-Dimensional Computed Tomography Reconstructions May Detect Pincer Lesions With Higher Sensitivity Than Radiographs in Patients With Femoroacetabular Impingement Syndrome.

Purpose: To assess the diagnostic capability of radiographs (XRs) to detect pincer lesions compared with 3-dimensional (3D) computed tomography scans in patients undergoing hip arthroscopy for femoroacetabular impingement syndrome (FAIS). Methods: We performed a retrospective review of all patients who underwent hip arthroscopy for FAIS between September 1, 2020, and October 2, 2022. Preoperative imaging was reviewed. Pincer lesions were defined as a lateral center-edge angle greater than 40°; a Tönnis angle greater than 0°; the presence of the ischial spine, crossover, or posterior wall sign; and the presence of overcoverage greater than 80%. Under "select criteria," patients were classified as having a pincer lesion on XRs and 3D computed tomography reconstructions (CTRs) based on the lateral center-edge angle or Tönnis angle alone, whereas "all criteria" added the presence of the crossover sign and coverage percentage. Statistical analysis was performed to determine the diagnostic accuracy of XRs compared with 3D CTRs. Results: A total of 69 patients met the inclusion criteria. There were 21 male patients (30.4%) and 48 female patients (69.6%). The mean age was 33 ± 13.5 years. χ2 Analysis for select criteria found that 3D CTR was more likely than XRs to detect a pincer lesion. χ2 Analysis for all criteria found that 3D CTR was more likely than XRs to detect a pincer lesion. χ2 Analysis further showed that when using XRs, a pincer lesion was more likely to be detected under all criteria than under select criteria. Likewise, when using 3D CTR, a pincer lesion was more likely to be detected under all criteria than under select criteria. Conclusions: In this study, we found that 3D CTR detected pincer lesions in patients undergoing hip arthroscopy for FAIS with significantly higher sensitivity than XRs alone. Level of Evidence: Level III, retrospective cohort study.

Erratum to 'Life-Threatening, Bleeding Pseudoaneurysm of the External Iliac Artery in the Setting of an Infected Total Hip Arthroplasty From Pasteurella multocida' [Arthroplasty Today 6 (2020) 560-565].

[This corrects the article DOI: 10.1016/j.artd.2020.06.014.].

Reduction of tert-butylphosphaalkyne and trimethylsilylnitrile with magnesium(I) dimers.

We report on the reactivity of magnesium(I) dimers, [Mg(nacnac)]2 (nacnac = HC[C(Me)N(2,6-iPr2C6H3)]2 ([DippLMg]2) and HC[C(Me)N(2,4,6-Me3C6H2)]2 ([MesLMg]2)), towards the phosphaalkyne tBuCP. The steric profile of the magnesium(I) dimer results in selectivity for different products. The larger diisopropylphenyl derivative yields exclusively the monomeric dimagnesiated phosphaalkene [DippLMg]PC(tBu)([DippLMg]) (1), while the mesityl derivative facilitates reductive coupling of two phosphaalkyne equivalents to give access to the 1,3-diphosphacyclobutadienediide [MesLMg]2[(tBu)2C2P2](2). The reactivity differs in coordinating solvents such as THF, which allowed for the observation of C-P coupled products. For sake of comparison, reactions of magnesium(I) compounds with Me3SiCN were carried out. In contrast to the reactions involving tBuCP, these afforded 1,3-diazabutadienediyl complexes via reductive coupling and silyl migration processes.

N-Heterocyclic carbene, carbodiphosphorane and diphosphine adducts of beryllium dihalides: synthesis, characterisation and reduction studies.

Reaction of several N-heterocyclic carbenes, a carbodiphosphorane, and bis(diphenylphosphino)ethane (DPPE) with [BeX2(OEt2)2] (X = Br or I) have yielded a variety of beryllium dihalide adduct complexes, all of which were crystallographically characterised. Attempts to reduce the compounds to low oxidation state beryllium complexes using a variety of reducing agents have been carried out, but were of limited success. However, reaction of [(IPr)BeBr2] (IPr = :C{(DipNCH)2}; Dip = 2,6-diisopropylphenyl) with the aluminium(i) heterocycle, [:Al(DipNacnac)] (DipNacnac = [HC(MeCNDip)2]-) afforded the adduct complex, [{(IPr)(Br)Be(µ-H)}2], while reduction of [(IPr)BeBr2] with potassium naphthalenide gave the beryllium naphthalenediyl complex, [(IPr)Be(C10H8)]. Furthermore, reaction of [{(DPPE)BeI2}∞], with [:Al(DipNacnac)] led to insertion of the Al centre of the heterocycle into a Be-I bond, and formation of a rare example of an Al-Be bonded complex, [(DPPE)(i)Be-Al(i)(DipNacnac)].

C-N and C-H Activation of an N-Heterocyclic Carbene by Magnesium(II) Hydride and Magnesium(I) Complexes.

Reactions of the hindered N-heterocyclic carbene, :C{(MesNCH)2} (IMes; Mes = mesityl), with a series of ß-diketiminatomagnesium(II) hydride and dimagnesium(I) complexes were carried out at 80 °C. The reactions involving the magnesium hydrides, [{(ArNacnac)Mg(µ-H)}2] [ArNacnac = [(ArNCMe)2CH]-, where Ar = 2,6-diethylphenyl (Dep) or 2,6-diisopropylphenyl (Dip)], proceeded via activation of an exocyclic C-N bond of IMes, giving magnesium imidazolyl compounds [(ArNacnac)Mg(µ-H)(µ-Imid)Mg(ArNacnac)] (Imid = [NC2H2N(Mes)C]-) and mesitylene. A low-yield IMes methyl C-H activation product, [(DepNacnac)Mg(IMes-H)], was also obtained, via H2 elimination, from the reaction between IMes and [{(DepNacnac)Mg(µ-H)}2]. Reactions between IMes and dimagnesium(I) compounds [{(ArNacnac)Mg}2] [Ar = 2,6-dimethylphenyl (Xyl) or Mes] afforded isostructural C-H activation products [(ArNacnac)Mg(IMes-H)] but in higher yields. Density functional theory calculations suggest that the reactions do not progress via stable adduct complex intermediates, which are sterically inaccessible.

Life-Threatening, Bleeding Pseudoaneurysm of the External Iliac Artery in the Setting of an Infected Total Hip Arthroplasty from Pasteurella multocida.

We present a bleeding, infected (mycotic) pseudoaneurysm from the organism Pasteurella multocida. The patient presented septic from an infected total hip arthroplasty and was treated with surgical debridement, component retention, and antibiotics. She re-presented with hip pain and a marked hemoglobin decrease. Vascular studies revealed a pseudoaneurysm of the external iliac artery and large hematoma secondary to contiguous spread of her hip infection. The pseudoaneurysm was treated with an endovascular stent before further debridement surgery to avoid exsanguinating hemorrhage with surgical release of her tamponade. This case demonstrates the utmost importance of recognizing and treating vascular pathology in a patient with an infected prosthetic hip, large hematoma, and decreased hemoglobin.

Diagonally Related s- and p-Block Metals Join Forces: Synthesis and Characterization of Complexes with Covalent Beryllium-Aluminum Bonds.

Additions of beryllium-halide bonds in the simple beryllium dihalide adducts, [BeX2 (tmeda)] (X=Br or I, tmeda=N,N,N',N'-tetramethylethylenediamine), across the metal center of a neutral aluminum(I) heterocycle, [:Al(Dip Nacnac)] (Dip Nacnac=[(DipNCMe)2 CH]- , Dip=2,6-diisopropylphenyl), have yielded the first examples of compounds with beryllium-aluminum bonds, [(Dip Nacnac)(X)Al-Be(X)(tmeda)]. For sake of comparison, isostructural Mg-Al and Zn-Al analogues of these complexes, viz. [(Dip Nacnac)(X)Al-M(X)(tmeda)] (M=Mg or Zn, X=I or Br) have been prepared and structurally characterized. DFT calculations reveal all compounds to have high s-character metal-metal bonds, the polarity of which is consistent with the electronegativities of the metals involved. Preliminary reactivity studies of [(Dip Nacnac)(Br)Al-Be(Br)(tmeda)] are reported.

Intraoperative utilization of advanced imaging modalities in a complex kidney stone case: a pilot case study.

PURPOSE: Despite the increasing use of advanced 3D imaging techniques and 3D printing, these techniques have not yet been comprehensively compared in a surgical setting. The purpose of this study is to explore the effectiveness of five different advanced imaging modalities during a complex renal surgical procedure. METHODS: A patient with a horseshoe kidney and multiple large, symptomatic stones that had failed Extracorporeal Shock Wave Lithotripsy (ESWL) and ureteroscopy treatment was used for this evaluation. CT data were used to generate five different imaging modalities, including a 3D printed model, three different volume rendered models, and a geometric CAD model. A survey was used to evaluate the quality and breadth of the imaging modalities during four different phases of the laparoscopic procedure. RESULTS: In the case of a complex kidney procedure, the CAD model, 3D print, volume render on an autostereoscopic 3D display, interactive and basic volume render models demonstrated added insight and complemented the surgical procedure. CAD manual segmentation allowed tissue layers and/or kidney stones to be made colorful and semi-transparent, allowing easier navigation through abnormal vasculature. The 3D print allowed for simultaneous visualization of renal pelvis and surrounding vasculature. CONCLUSIONS: Our preliminary exploration indicates that various advanced imaging modalities, when properly utilized and supported during surgery, can be useful in complementing the CT data and laparoscopic display. This study suggests that various imaging modalities, such as ones utilized in this case, can be beneficial intraoperatively depending on the surgical step involved and may be more helpful than 3D printed models. We also present factors to consider when evaluating advanced imaging modalities during complex surgery.

Greater neurobehavioral deficits occur in adult mice after repeated, as compared to single, mild traumatic brain injury (mTBI).

Mild traumatic brain injury (mTBI) accounts for the majority of all brain injuries and affected individuals typically experience some extent of cognitive and/or neuropsychiatric deficits. Given that repeated mTBIs often result in worsened prognosis, the cumulative effect of repeated mTBIs is an area of clinical concern and on-going pre-clinical research. Animal models are critical in elucidating the underlying mechanisms of single and repeated mTBI-associated deficits, but the neurobehavioral sequelae produced by these models have not been well characterized. Thus, we sought to evaluate the behavioral changes incurred after single and repeated mTBIs in mice utilizing a modified impact-acceleration model. Mice in the mTBI group received 1 impact while the repeated mTBI group received 3 impacts with an inter-injury interval of 24h. Classic behavior evaluations included the Morris water maze (MWM) to assess learning and memory, elevated plus maze (EPM) for anxiety, and forced swim test (FST) for depression/helplessness. Additionally, species-typical behaviors were evaluated with the marble-burying and nestlet shredding tests to determine motivation and apathy. Non-invasive vibration platforms were used to examine sleep patterns post-mTBI. We found that the repeated mTBI mice demonstrated deficits in MWM testing and poorer performance on species-typical behaviors. While neither single nor repeated mTBI affected behavior in the EPM or FST, sleep disturbances were observed after both single and repeated mTBI. Here, we conclude that behavioral alterations shown after repeated mTBI resemble several of the deficits or disturbances reported by patients, thus demonstrating the relevance of this murine model to study repeated mTBIs.