Procrustes analysis of a shape of pediatric supracondylar humerus fractures.

Shape of supracondylar fracture of the humeral of pediatric patients is analysed with Procrustes method. XR-images of fractures are considered both in anterio-posterior (AP) view and in a lateral (L) view. Applying Procrustes method for both views mean images are constructed and compared. Variability of shapes is quantified with a shape principal component analysis. Possibility of predictions of typical shape of humeral fracture and its variability using statistical shape analysis offers additional information on injury characteristics important in preoperative planning. Non-parametric tests (permutational and bootstrap) do not indicate statistical difference between Procrustes mean shapes in anterio-posterior and lateral projections. It is shown, however, that AP and L shapes of humeral fractures differ in their variability quantified by shape principal components.

Supracondylar Fractures of the Humerus: Association of Neurovascular Lesions with Degree of Fracture Displacement in Children-A Retrospective Study.

Supracondylar humerus fractures (ScHF) account for 60% of fractures of the elbow region in children. We assessed the relationship between neurovascular complications and the degree of fracture displacement as rated on the basis of modified Gartland classification. Moreover, we aimed to evaluate predisposing factors, e.g., age and gender, and outcomes of neurovascular complications in ScHF. Between 2004 and 2019, we treated 329 patients with ScHF at the Department of Traumatology and Orthopedics of the Upper Silesian Child Centre, Katowice, Poland. Mean age of patients (189 boys and 140 girls) was 7.2 years (Confidence interval: 6.89, 7.45). Undisplaced fractures were treated conservatively with a cast. Displaced fractures were managed by closed reduction and percutaneous Kirschner wire fixation using two pins inserted laterally. We retrospectively assessed the number of neurovascular lesions at baseline and recorded any iatrogenic injury resulting from the surgical intervention. Acute neurovascular lesions occurred in 44 of 329 ScHF patients (13.4%). The incidence of accompanying neurovascular injuries was positively associated with the severity of fracture displacement characterized by Gartland score. Vascular injuries occurred mainly in Gartland type IV ScHF, while nerve lesions occurred in both Gartland type III and IV ScHF. We noted a significantly higher mean Gartland score and mean age at injury in the group of children suffering from neurovascular injuries when compared to those in the group without such injuries (p = 0.045 and p = 0.04, respectively). We observed no secondary nerve lesions after surgical treatment. For the treatment of ScHF in children, we recommend closed reduction and stabilization of displaced fractures with K-wires inserted percutaneously from the lateral aspect of the upper arm. We advocate vessel exploration in case of absent distal pulses after closed reduction but do not consider primary nerve exploration necessary, unless a complete primary sensomotoric nerve lesion is present.

Surgical treatment of benign lesions and pathologic fractures of the proximal femur in children.

PURPOSE: Benign lesions of the proximal femur region, such as simple bone cysts, aneurysmal bone cysts, and fibrous dysplasia, are common in children. Benign lesions may cause pathologic fractures, limb length inequities, and growth disturbances. Differential diagnoses, e.g., malignant bone tumors and osteomyelitis, are sometimes difficult to rule out. OBJECTIVE: We aimed to evaluate outcomes in children with benign lesions of the proximal femur treated with curettage, bone grafting, and plate fixation. METHODS: In this retrospective study, we included 30 children (median age 10.5 years; range 1.1-17.8 years) suffering from bone cysts and tumor-like lesions of the proximal femur region treated between 2002 and 2018. We analyzed plain X-ray images and CT scans in all children and obtained MRI scans in a selected group of children (63.3%). We examined histopathologic biopsy results for all bone lesions before initiating treatment. Surgical management comprised tumor curettage with adjuvant high-speed drilling and allogenic bone grafting supplemented by bone graft substitutes before plate fixation. Median follow-up interval was 87 months (range 24-156 months). We evaluated the healing of lesions according to Capanna's classification and rated functional outcomes according to Merle d'Aubigné and Postel score. RESULTS: Overall, 25 of 30 (83.3%) patients were admitted to hospital because of a pathologic fracture. We diagnosed simple bone cysts in 15 (50.0%) patients, aneurysmal bone cysts in 7 (23.5%) patients, and fibrous dysplasia in 8 (26.5%) patients. Bone consolidation was achieved in 22 of 30 (73.3%) patients after a mean of 5 months (range 3-7 months). The main complication was recurrence of the lesion in 4 of 30 (13.3%) patients. With respect to the Merle d'Aubigné and Postel scores, 17 of 30 (56.7%) patients obtained an excellent result (18 points), while 12 (40.0%) patients had a good result (15-17 points) and only 1 (3.3%) patient had a fair result (14 points). CONCLUSION: Surgical treatment of bone cysts and tumor-like lesions of the proximal femur by local resection or destruction of the lesion, followed by filling the defect with bone graft material and internal stabilization represents a safe and effective treatment option in children. LEVEL OF EVIDENCE: Therapeutic, retrospective comparative study-Level III.

Currents in a Quantum Nanoring Controlled by Non-Classical Electromagnetic Field.

Quantum ring accommodating interacting spin-less fermions threaded by magnetic flux with a non-classical component added to a static, inducing persistent current, is considered. It is investigated how current flowing in the ring becomes affected by a state of non-classical flux and how Coulomb interaction between fermions influences entanglement of quantum ring and the driving field. In particular it is shown that in an absence of decoherence and under certain conditions fermion-fermion interaction is necessary for a ring-field entanglement to occur.

Statistical image analysis and escort histograms in characterization of articular cartilage repair in a skeleton animal model.

Statistical image analysis of an ensemble of digital images of histological samples is performed as an auxiliary investigation a result of the recently proposed method of articular cartilage repair utilizing growth plate chondrocytes in a skeleton animal model. A fixed-shift model of maximal likelihood estimates of image histograms applied for monochromatic (grayscale) images or their RGB components confirms the statistically significant effect of the previously proposed medical treatment. The type of staining used to prepare images of histological samples is related to the visibility of the effectiveness of medical treatment. Hellinger distance of escort distributions for maximal likelihood estimates of image histograms of medically treated and control samples is investigated to identify grayscale (or RGB) intensities responsible for statistically significant difference of the estimates. A difference of Shannon entropy quantifying informational content of the histograms allows one to identify staining and image colors which are most suitable to visualize cluster formation typical for articular cartilage repair processes.

Faint trace of a particle in a noisy Vaidman three-path interferometer.

We study weak traces of particle passing Vaidman's nested Mach-Zehnder interferometer. We investigate an effect of decoherence caused by an environment coupled to internal degree of freedom (a spin) of a travelling particle. We consider two models: pure decoherence leading to exact results and weak coupling Davies approximation allowing to include dissipative effects. We show that potentially anomalous discontinuity of particle paths survives an effect of decoherence unless it affects internal part of the nested interferometer.

Binary Communication with Gazeau-Klauder Coherent States.

We investigate advantages and disadvantages of using Gazeau-Klauder coherent states for optical communication. In this short paper we show that using an alphabet consisting of coherent Gazeau-Klauder states related to a Kerr-type nonlinear oscillator instead of standard Perelomov coherent states results in lowering of the Helstrom bound for error probability in binary communication. We also discuss trace distance between Gazeau-Klauder coherent states and a standard coherent state as a quantifier of distinguishability of alphabets.

Quantum Two Player Game in Thermal Environment.

A two-player quantum game is considered in the presence of thermal decoherence. It is shown how the thermal environment modeled in terms of rigorous Davies approach affects payoffs of the players. The conditions for either beneficial or pernicious effect of decoherence are identified. The general considerations are exemplified by the quantum version of Prisoner Dilemma.