UNASSIGNED: Dynamic interaction of cam and pincer deformities can result in pathological contact forces in femoroacetabular impingement (FAI) syndrome. Similar deformities were noted during acetabular fracture reconstruction. We hypothesise that the prevalence of FAI deformity is higher in patients sustaining acetabular fractures than in a control group.
UNASSIGNED: This retrospective radiographic study compared the parameters that define FAI deformity in 100 patients consecutively admitted to a trauma unit with an acetabular fracture and a control group of 100 patients with lateral compression pelvic fracture without acetabular injury. Both underwent identical clinical imaging. Centre-edge angles (CEA) and alpha angles were used to define patients with pincer, cam, or mixed FAI deformity.
UNASSIGNED: There were significantly more patients with FAI deformity in the acetabular fracture group than in the control group (71% vs. 18%, p < 0.0001). There were considerably more fractures involving both anterior and posterior acetabular columns in patients with \'pincer\' sockets (p = 0.02, OR = 2.95, 95% CI, 1.12-7.78).
UNASSIGNED: There is a high prevalence of cam and pincer deformities in patients with acetabular fractures, particularly bi-column fractures.

The pincer complexes [NiIIBr(CNC)]Br (4), [CrIIIBr3(CNC)] (5 a) and [CrIIIBr2.3Cl0.7(CNC)] (5 b), where CNC=3,3\'-(pyridine-2,6-diyl)bis(1-mesityl-3,4,5,6-tetrahydropyrimidin-2-ylidene), were obtained from the novel ligand CNC, generated in situ from the precursor (CHNCH)Br2 and [NiIIBr2(PPh3)2] or from [CrII{N(SiMe3)2}2(THF)2] and (CHNCH)Br2 by aminolysis, respectively. The tetrahedrally distorted square planar (τ4≅0.30) geometry and the singlet ground state of Ni in 4 were attributed to steric constraints of the CNC backbone. Computational methods highlighted the dependence of the coordination geometry and the singlet-triplet energy difference on the size of the N-substituent of the tetrahydropyrimidine wingtips and contrasted it to the situation in 5-membered imidazolin-2-ylidene pincer analogues. The octahedral CrIII metal center in 5 a and 5 b is presumably formed after one electron oxidation from CH2Cl2. 4/MAO and 5 a/MAO were catalysts of moderate activity for the oligomerization and polymerization of ethylene, respectively. The analogous (CH^N^CH)Br2 precursor, where (CH^N^CH)=3,3\'-(pyridine-2,6-diylbis(methylene))bis(1-mesityl-3,4,5,6-tetrahydropyrimidin-1-ium), was also prepared, however its coordination chemistry was not studied due to the inherent instability of the resulting free C^N^C ligand.

BACKGROUND: With the recent interest in hip-spine relationship, the link between femoroacetabular impingement (FAI) and the lumbar-pelvic-femoral complex (LPFC) appears decisive. The objectives of this study were (1) to compare the pelvic version, as well as (2) all the parameters of the LPFC between two populations of healthy subjects, comparing those with radiological signs of FAI to those without and finally, (3) to evaluate the LPFC parameters according to the type of FAI.
OBJECTIVE: Asymptomatic subjects with radiological signs of FAI had superior pelvic anteversion.
METHODS: This retrospective study was based on a prospective cohort of 118 voluntary asymptomatic patients including 62 men (52.5%) with a mean age of 25.6 years±4.4 (19-39). The following parameters: pelvic version (PV), pelvic incidence (PI), lumbar lordosis (LL), sacral slope (SS), hip flexion, intrinsic (IER) and extrinsic (EER) extension reserve were measured using EOS imaging™ in the reference standing position and the lunge position. The radiological signs of FAI (cam, pincer, mixed) were identified on these acquisitions then separated into 2 groups. The first was the group presenting with one or more images of FAI (FAI+) and the second group with no images of FAI (FAI-).
RESULTS: There were 143 hips in the FAI+ group compared to 93 hips in the FAI- group. There were 36.4% cams and 45% pincers. With an average of 9.08°±7.81 (-11.0; 27.0) versus 12.33°±8.94 (-5.0; 55.0), the PV was significantly lower (p=0.022) in the FAI+ group compared to the FAI- group. A post-hoc power analysis on the primary outcome (PV) confirmed sufficient power (1-β=0.809). Compared to the FAI- group, the cam group presented a significantly lower IER and EER (respectively p=0.014 and p=0.047). The comparative analysis between the FAI- and pincer groups found a significant difference in PI (p=0.001), PV (p<0.001), IER (p=0.017) and hip flexion (p<0.001), SS in lunge position (p=0.031) and EER (p=0.039).
CONCLUSIONS: Asymptomatic subjects with radiographic signs of FAI present with weak pelvic version when standing. This pelvic hyper-anteversion is mainly found in the event of a radiological pincer sign.
METHODS: III, retrospective comparative study.

UNASSIGNED: The amount of resection or the starting point of the resection on the femoral head for cam lesions in femoroacetabular impingement (FAI) is controversial.
UNASSIGNED: The purpose of this study was to study the effect of postoperative resection depth, and resection arc ratio of cam lesion on the frequency of achieving substantial clinical benefit (SCB), patient acceptable state (PASS) in modified Harris Hip Score (mHHS) and Hip Outcome Score Activity of Daily Living (HOSADL), 2 years postoperatively.
UNASSIGNED: All patients who underwent first-time hip arthroscopy for FAI with a 2-year follow-up were included in this study. Patient-reported outcomes included the mHHS, HOSADL, and visual analogue scale for pain (Pain VAS). Radiological parameters such as alpha angletraditional (αT), alpha anglecartilage (αC), resection arc ratio (% alpha anglecartilage-alpha angletraditional/360°), resection depth (\'\'D\'\'mm) and resection depth ratio \'D%\' (D/femoral head diameter %) were measured using the 45° Dunn view.
UNASSIGNED: We identified 26 patients (27 hips) with 2-year follow-up. There were 10 female and 16 male patients. The mean age of the patients was 33 ± 12 years.Higher frequency of achieving SCB threshold for mHHS was related to labrum repair (73% vs. debridement \'27%\' p = 0.03), lower preoperative αT (64° vs. 76°, p = 0.04), lower preoperative mHHS (54 vs. 81, p < 0.001) and higher preoperative VAS scores (8 vs. 7, p = 0.02). Higher frequency of reaching PASS threshold for mHHS was associated with lower αC (82°vs. 92° p:0.02), lower RA (8% vs. 11%, p = 0.03), lower D (2.8 mm vs. 4.5 mm p:0.03), lower D% (4.7% vs. 8.4% p = 0.04) and higher postoperative mHHS (97 vs. 82 p < 0.001).
UNASSIGNED: A higher frequency of achieving SCB for HOSADL was related to lower D% (5% vs. 10.5%, p = 0.04).Cam resection depth affects the frequency of achieving clinically meaningful scores and resection depth less than 6% of the femoral head diameter seems to be appropriate for optimal results. The starting point of resection on head cartilage needs to be <90° when alpha angle is used for reference.

Cofactors are essential components of numerous enzymes, therefore their characterization by structural, biophysical, and biochemical approaches is crucial for understanding the resulting catalytic and regulatory mechanisms. In this chapter, we present a case study of a recently discovered cofactor, the nickel-pincer nucleotide (NPN), by demonstrating how we identified and thoroughly characterized this unprecedented nickel-containing coenzyme that is tethered to lactase racemase from Lactiplantibacillus plantarum. In addition, we describe how the NPN cofactor is biosynthesized by a panel of proteins encoded in the lar operon and describe the properties of these novel enzymes. Comprehensive protocols for conducting functional and mechanistic studies of NPN-containing lactate racemase (LarA) and the carboxylase/hydrolase (LarB), sulfur transferase (LarE), and metal insertase (LarC) used for NPN biosynthesis are provided for potential applications towards characterizing enzymes in the same or homologous families.

Polyethyleneimines find many applications in products such as detergents, adhesives, cosmetics, and for processes such as tissue culture, gene therapy, and CO2 capture. The current state-of-the-art technology for the production of the branched polyethyleneimines involves aziridine feedstock which is a highly toxic, volatile and mutagenic chemical and raises significant concern to human health and environment. We report here a novel method for the synthesis of branched polyethyleneimine derivative from ethylene glycol and ethylenediamine which are much safer, environmentally benign, commercially available and potentially renewable feedstock. The polymerisation reaction is catalysed by a complex of an earth-abundant metal, manganese and liberates H2 O as the only by-product. Our mechanistic studies using a combination of DFT computation and experiment suggest that the reaction proceeds by the formation and subsequent hydrogenation of imine intermediates.

BACKGROUND: Imaging studies play a crucial role in diagnosing femoroacetabular impingement (FAI), including plain radiography and Magnetic Resonance Imaging (MRI). FAI is a combined pathology of bony abnormality, labral and labrocartilagenous erosions. Surgical treatment for such cases has become more established and preoperative imaging is the roadmap that includes the assessment of labrum and articular cartilage.
METHODS: During a period of 2 years, thirty-seven patients with a clinical diagnosis of FAI were retrospectively enrolled in this study, including 17 men and 20 women, aged 27-62 years. There were 22 right hips and 15 left hips. MRI was done for all patients to identify bony details, labral and chondral abnormalities and to exclude coexisting disorders. The imaging findings were compared with the arthroscopic data.
RESULTS: 15 patients had Pincer FAI, 11 patients had CAM, and 11 patients had combined Cam/Pincer FAI. Labral tear was detected in 100 % of patients, 97 % had an anterosuperior labral tear. 82 % of patients had partial thickness cartilage lesions and 8 % had full thickness cartilage lesions. MRI had a sensitivity of 100 % compared to hip arthroscopy in detecting labral tear, 60 % in detecting cartilage erosion.
CONCLUSIONS: Conventional hip MRI detects bony changes in FAI, type of impingement and associated labral tear and cartilage erosions in comparison to the hip arthroscopy.

UNASSIGNED: Femoroacetabular impingement (FAI) appears common in ice hockey, but there is a lack of data examining pincer-type impingement in women\'s ice hockey athletes. The objective of this study was to assess the prevalence of pincer-type impingement in National Women\'s Hockey League (NWHL) athletes. Our hypothesis was that there would be an increased prevalence of pincer impingement in these athletes.
UNASSIGNED: Data were gathered for a team of NWHL players, and age, gender, and body mass index (BMI) matched controls were also retrospectively collected. All subjects were above 18 years of age. Control patients were excluded if they had undergone prior hip surgery, were greater than age 30, or had BMI greater than 35. Radiographs of both groups were assessed for lateral center edge angle (LCEA), Tönnis angle, and crossover sign. Tönnis angle <0 or LCEA >40 degrees was considered pincer morphology. An alpha angle >55 degrees was considered cam morphology.
UNASSIGNED: Thirty-seven NWHL players and 37 female controls were included. Overall 32% of the players had a pincer lesion in either hip based on LCEA, 8% had a Tönnis angle <0, and 22% had a crossover sign in either hip compared to 9%, 19%, and 13% for the controls, respectively. None of these findings were significantly different between the groups (p > 0.05). An alpha angle ≥55 degrees in either hip was found in 84% of players, but lateral Dunn images for alpha angle measurements were not available for the control group.
UNASSIGNED: Pincer-type morphology and crossover signs were present in a larger portion of NWHL players than has been reported in the general population, but these findings were not statistically different than in the control group. Cam-type morphology was even more prevalent in these athletes and may be related to age at menarche due impingement at the physis prior to closure.

Femoro-acetabular impingement (FAI) syndrome is one of the most studied conditions in sports medicine. Surgical or conservative approaches can be proposed for treating FAI, although the best standard of care is not established yet. Our aim is to provide a comprehensive review of the best treatment for FAI syndrome evaluating differences in outcomes between surgical and non-operative management. A literature search was carried out on the PubMed, EMBASE, Scopus, and PEDro databases, using the following keywords: \"femoroacetabular impingement\", \"FAI\", in association with \"surgery\", \"arthroscopy\", \"surgical\" and \"conservative\", \"physiotherapy\", \"physical therapy\", \"rehabilitation\", \"exercise\". Only Level I RCTs were included. Four articles were selected for this systematic review. Our analysis showed different therapeutic protocols, follow-up periods, and outcomes; however, three out of the four studies included favored surgery. Our study demonstrates beneficial effects for both arthroscopic treatment and a proper regimen of physical therapy, nevertheless a surgical approach seemed to offer superior short-term results when compared to conservative care only. Further trials with larger sample sizes and longer follow-ups are needed to assess the definitive approach to the FAI condition.

Sulfur-insertion reactions are essential for the biosynthesis of several cellular metabolites, including enzyme cofactors. In Lactobacillus plantarum, a sulfur-containing nickel-pincer nucleotide (NPN) cofactor is used as a coenzyme of lactic acid racemase, LarA. During NPN biosynthesis in L. plantarum, sulfur is transferred to a nicotinic acid-derived substrate by LarE, which sacrifices the sulfur atom of its single cysteinyl side chain, forming a dehydroalanine residue. Most LarE homologs contain three conserved cysteine residues that are predicted to cluster at the active site; however, the function of this cysteine cluster is unclear. In this study, we characterized LarE from Thermotoga maritima (LarETm) and show that it uses these three conserved cysteine residues to bind a [4Fe-4S] cluster that is required for sulfur transfer. Notably, we found LarETm retains all side chain sulfur atoms, in contrast to LarELp. We also demonstrate that when provided with L-cysteine and cysteine desulfurase from Escherichia coli (IscSEc), LarETm functions catalytically with IscSEc transferring sulfane sulfur atoms to LarETm. Native mass spectrometry results are consistent with a model wherein the enzyme coordinates sulfide at the nonligated iron atom of the [4Fe-4S] cluster, forming a [4Fe-5S] species, and transferring the noncore sulfide to the activated substrate. This proposed mechanism is like that of TtuA that catalyzes sulfur transfer during 2-thiouridine synthesis. In conclusion, we found that LarE sulfur insertases associated with NPN biosynthesis function either by sacrificial sulfur transfer from the protein or by transfer of a noncore sulfide bound to a [4Fe-4S] cluster.