Influence of Preoperative Deformity on Flexion Gap Asymmetry in Measured Resection Technique: A Theoretical Study in Navigated Gap Balancing Total Knee Arthroplasties, Done for Varus Knee Osteoarthritis.

INTRODUCTION: Disagreement exists on (a) achieving a symmetrical flexion gap and (b) the influence of varus deformity on the flexion gap asymmetry (FGA) in measured resection (MR) total knee arthroplasty (TKA). We aimed to determine the FGA and influence of preoperative deformity on the FGA, based on the MR technique, in varus knee osteoarthritis. METHODS: In 321 navigated TKAs, we released the soft tissues in extension. In 90° flexion, with the tensioner in situ, we calculated the FGA, the angle between the posterior femoral cut (planned 3° external rotation to the posterior condylar line, parallel to the surgical transepicondylar axis, or perpendicular to the Whiteside line) and the proximal tibial resection plane. RESULTS: The FGA values varied widely, and the risk of >2° and >3° FGA was present in at least 60% and 40% knees, respectively. These risks were high in knees with moderate and severe varus deformity. CONCLUSIONS: In varus knee osteoarthritis, the risk of FGA (based on the MR technique) was high, especially when the deformity was moderate to severe. Caution is required in MR TKA, and surgeons must consider safer alternatives (gap balancing or hybrid technique) to achieve a symmetrical flexion gap in these knees.

Pyomyositis of the Piriformis Muscle-A Case of Piriformis Syndrome.

Piriformis syndrome is a rare cause of sciatica, which results in low backache due to sciatic nerve compression. This syndrome is associated with abnormalities in the piriformis muscle, which cause sciatic nerve entrapment, like anatomical variations, muscle hypertrophy, and inflammation. It can also result from the abnormal course of sciatic nerve itself through normal piriformis muscle. Piriformis syndrome due to pyomyositis of the piriformis muscle is extremely rare and only 23 cases are reported in literature. Herein, we report one such rare case of a patient, with pyomyositis of piriformis muscle, who presented with piriformis syndrome.

Effect of Time Lag from Injury to Surgery on the Temporal Expression of Growth Factors After Intramedullary Nailing of Isolated Fracture of Femur Shaft.

BACKGROUND: Growth factors are considered to play an important role in the process of bone healing. This study assessed serum levels of transforming growth factor-ß1 (TGF-ß1) and vascular endothelial growth factor (VEGF) in patients undergoing intramedullary nailing for isolated fracture of femur shaft operated at various time lag from injury. PATIENTS AND METHODS: All patients between 18 and 60 years of age group operated for isolated femoral shaft fractures (AO/OTA32 A, B, C) were included. The serum levels of VEGF and TGF-ß1 were compared at various intervals amongst the study group divided into two groups based on the time lag between injury and surgery along with a health control cohort. RESULTS: 31 patients were operated within the first 48 h while 28 patients were operated within 2-12 days after injury. Highest VEGF levels were observed on postop day 3, followed by a subsequent decline thereafter. TGF-ß1 level also showed increasing trend after surgery, but the levels reached dual peaks after 2 weeks and 12 weeks after surgery. Both groups revealed similar trends of temporal expression of serum VEGF and TGF-ß1. There was no statistical difference between the two groups at any point of time during the observation period. There was also no statistical difference in clinico-radiological healing of fractures among the groups. CONCLUSION: There is a definite and specific trend of serum levels of growth factors in the fracture healing process. There is no effect of time lag from injury to surgery on the healing outcome of isolated femoral shaft fractures both at the molecular level and also at the clinical level.

Dynamics of the occurrence of influenza in relation to seasonal variation in Chennai, Tamil Nadu: A 7 -year cumulative study.

Background: Influenza viruses have emerged as virulent pathogens causing considerable burden across the world. A thorough understanding of the pattern in occurrence of influenza globally is the need of hour. The present study deals with analysis of the dynamics of Influenza virus, especially the influence of seasonal change on viral circulation and causation of epidemics/pandemics in the context of subtropical region. Methods: During the 7 year (2009-2015) study, 36670 specimens were subjected to influenza analysis. Nasopharyngeal swabs collected from suspected patients from Chennai, Tamil Nadu, were tested and typed by real-time polymerase chain reaction assay. Results: During 2009 pandemic, among influenza A positives 95.16% were Apdm09, indicating that there was a predominant circulation of Apdm09. During postpandemic period, there were waves in the occurrence of Apdm09 which indicates fall in immunity with buildup in the susceptible population. Conclusion: In Chennai, Tamil Nadu, influenza positivity started with the onset of monsoon and peaks during the postmonsoon months throughout the study period. The assessment of meteorological factors compounding influenza activity can help in raising alerts to the public health officials of impending disaster which suggests that Influenza vaccination can be initiated before monsoon months in South India.

A Case Report of Dyschromatosis Universalis Hereditaria (DUH) with Primary Ovarian Failure (POF).

Dyschromatosis Universalis Hereditaria (DUH) belongs to a group of congenital diffuse reticulate pigmentary disorders characterised by both hypo and hyper pigmented macules. It is both hereditary and sporadic. A number of associated cutaneous and systemic diseases have been reported. The recent discovery of the mutation in ATP binding cassette protein, ABCB6 in DUH attempts to explain the reason behind the pigmentary abnormalities and varied associations. We add a new association by reporting a case of DUH with primary ovarian failure (POF) and hypothyroidism.

Anterior fracture dislocation of sacroiliac joint: A rare type of crescent fracture.

Crescent fractures of the pelvis are usually described as posterior sacro iliac fracture dislocations. Rarely anterior displacement of the fractured iliac fragment along with dislocation has been reported in crescent fractures. Four cases of anterior fracture dislocation of the sacro iliac joint managed in the last two years by a single surgeon are presented. The injury mechanism, radiological diagnosis, management protocol along with functional outcomes of all the four patients have been discussed. CT scan is essential in the diagnosis and preoperative planning of this injury pattern. Early fixation along with proper reduction leads to excellent functional outcome in this subset of lateral compression injuries of the pelvis.

Takayasu's arteritis--stroke as an initial presentation.

Takayasu's arteritis (TA) is a chronic inflammatory disease of unknown cause. Stroke as a initial presentations without any systemic symptoms are rare. We had two cases of Takayasu's arteritis whose initial presentation were stroke without any significant systemic symptoms. So early detection and initiation of treatment lessens the chance of progression of disease and involvement of other organ system.

Loose bodies in right elbow joint: Post traumatic? or post infective?

Tuberculous osteomyelitis after open fracture is uncommon. Early diagnosis of tubercular arthritis is difficult because of insidious onset, indolent process and mild or non specific local or systemic symptoms. This case report describes the fibrinous loose bodies in elbow joint of a patient who sustained a compound fracture presented with chronic non healing discharging sinus. Intra-operatively some suspected seed like bodies were removed and sent for histopathological examination which showed circumscribed homogenous fibrinous bodies with focal area of hyalinization and few embedded tiny osteolytic fragments. Acid Fast Bacilli staining was positive. The patient had a good recovery after treatment with anti-tuberculosis drugs.

Dengue disease status in Chennai (2006-2008): a retrospective analysis.

BACKGROUND & OBJECTIVES: Dengue is one of the most important Arboviral diseases in man with outbreaks in Southeast Asia and India. We report a retrospective analysis of the dengue positivity in the referred samples for three years period (2006 to 2008) at the Department of Virology, King Institute of Preventive Medicine, Chennai, Tamil Nadu, India. METHODS: Serum samples from 1593 suspected cases (968 male and 625 female) were obtained. Of the 1593 cases screened, 1204 (75.5%) were paediatric cases and 389 (24.4%) adults. The samples were subjected to MAC ELISA and IgG ELISA. RESULTS: Of the 968 patients, 686 (43.0%) were positive, of which 579 (84.0%) were in the paediatric age group (<14 yr) and 107 (15.5%) were adults. The IgM positivity being 356 (36.7%) in males and 330 (52.8%) in females. Of the 686 positives, 113 (16.47%) were positive for both IgM and IgG denoting secondary infection. There was a noticeable increased occurrence during the cooler months and during the monsoon and post-monsoon months. INTERPRETATION & CONCLUSION: The dengue IgM seropositivity among the suspected cases indicates active dengue virus activity. Increase in the probable secondary infections especially in a country like ours where multiple serotypes are prevalent raises concern over probable increase in the incidence of the more serious DHF/DSS. Studies need to be done to identify circulating serotypes of dengue virus to design preventive strategies.

The management of wounds following primary lower limb arthroplasty: a prospective, randomised study comparing hydrofibre and central pad dressings.

Wound care following lower limb arthroplasty has not been subject to in-depth clinical research, primarily because such wounds usually heal without complication. However, when prosthetic implants are used, serious wound problems can be disastrous (Whitehouse et al. Infect Control Hosp Epidemiol 2002;23:183-9; Lindwell OM. Clin Orthop Relat Res 1986;211:91-103). We report the results of a prospective, randomised, controlled trial comparing a hydrofibre (Aquacel) and central pad (Mepore) dressing in the management of acute wounds following primary total hip or knee arthroplasty left to heal by primary intention. Dressing performance was measured in 61 patients receiving total hip or knee replacements. There was a significant reduction in the requirement for dressing changes before five postoperative days in the hydrofibre group (43% compared with 77% in the central pad group), and there were fewer blisters amongst patients in the hydrofibre group (13% compared with 26% in the central pad group). We conclude that there is a potential role for hydrofibre dressing in the management of arthroplasty wounds.

Voronoi neighbor statistics of homogeneously sheared inelastic hard disks and hard spheres.

In this work we extend our earlier Voronoi neighbor analysis [J. Chem. Phys. 123, 074502 (2005)] to homogeneously sheared inelastic hard-particle structures, the simplest model for rapid granular matter. The pair distribution function is partitioned into the nth neighbor coordination number (Cn), and the nth neighbor position distribution [fn(r)]. The distribution of the number of Voronoi faces (Pn) is also considered since C1 is its mean. We report the Cn and Pn for the homogeneously sheared inelastic hard-disk and hard-sphere structures. These statistics are sensitive to shear ordering transition, the nonequilibrium analogue of the freezing transition. In the near-elastic limit, the sheared fluid statistics approach that of the thermodynamic fluid. On shear ordering, due to the onset of order, the Cn for sheared structures approach that of the thermodynamic solid phase. The suppression of nucleation by the homogeneous shear is evident in these statistics. As inelasticity increases, the shear ordering packing fraction increases. Due to the topological instability of the isotropically perturbed face-centered cubic lattice, polyhedra with faces 12 to 18, with a mean at 14, coexist even in the regular close packed limit for the thermodynamic hard-sphere solid. In shear ordered inelastic hard-sphere structures there is a high incidence of 14-faceted polyhedra and a consequent depletion of polyhedra with faces 12, 13, 15-18, due to the formation of body-centered-tetragonal (bct) structures. These bct structures leave a body-centered-cubic-like signature in the Cn and Pn data. On shear ordering, close-packed layers slide past each other. However, with a velocity-dependent coefficient of restitution, at a critical shear rate these layers get disordered or amorphized. We find that the critical shear rate for amorphization is inversely proportional to the particle diameter, as compared to the inverse square scaling observed in dense colloidal suspensions.

Voronoi neighbor statistics of hard-disks and hard-spheres.

The neighbor distribution in hard-sphere and hard-disk fluids is analyzed using Voronoi tessellation. The statistical measures analyzed are the nth neighbor coordination number (Cn), the nth neighbor distance distribution [fn(r)], and the distribution of the number of Voronoi faces (Pn). These statistics are sensitive indicators of microstructure, and they distinguish thermodynamic and annealed structures. A sharp rise in the hexagon population marks the onset of hard-disk freezing transition, and Cn decreases sharply to the hexagonal lattice values. In hard-disk random structures the pentagon and heptagon populations remain significant even at high volume fraction. In dense hard-sphere (three-dimensional) structures at the freezing transition, C1 is close to 14, instead of the value of 12 expected for a face-centered-cubic lattice. This is found to be because of a topological instability, where a slight perturbation of the positions in the centers of a pair of particles transforms a vertex in the Voronoi polyhedron into a Voronoi surface. We demonstrate that the pair distribution function and the equation-of-state obtained from Voronoi tessellation are equal to those obtained from thermodynamic calculations. In hard-sphere random structures, the dodecahedron population decreases with increasing density. To demonstrate the utility of the neighbor analysis, we estimate the effective hard-sphere diameter of the Lennard-Jones fluid by identifying the diameter of the spheres in the hard-sphere fluid which has C1 equal to that for the Lennard-Jones fluid. The estimates are within 2% deviation from the theoretical results of Barker-Henderson and Weeks-Chandler-Andersen.

Voronoi cell volume distribution and configurational entropy of hard-spheres.

The Voronoi cell volume distributions for hard-disk and hard-sphere fluids have been studied. The distribution of the Voronoi free volume vf, which is the difference between the actual cell volume and the minimal cell volume at close packing, is well described by a two-parameter (2gamma) or a three-parameter (3gamma) gamma distribution. The free parameter m in both the 2gamma and 3gamma models is identified as the "regularity factor." The regularity factor is the ratio of the square of the mean and the variance of the free volume distribution, and it increases as the cell volume distribution becomes narrower. For the thermodynamic structures, the regularity factor increases with increasing density and it increases sharply across the freezing transition, in response to the onset of order. The regularity factor also distinguishes between the dense thermodynamic structures and the dense random or quenched structures. The maximum information entropy (max-ent) formalism, when applied to the gamma distributions, shows that structures of maximum information entropy have an exponential distribution of vf. Simulations carried out using a swelling algorithm indicate that the dense random-packed states approach the distribution predicted by the max-ent formalism, though the limiting case could not be realized in simulations due to the structural inhomogeneities introduced by the dense random-packing algorithm. Using the gamma representations of the cell volume distribution, we check the numerical validity of the Cohen-Grest expression [M. H. Cohen and G. S. Grest, Phys. Rev. B 20, 1077 (1979)] for the cellular (free volume) entropy, which is a part of the configurational entropy. The expression is exact for the hard-rod system, and a correction factor equal to the dimension of the system, D, is found necessary for the hard-disk and hard-sphere systems. Thus, for the hard-disk and hard-sphere systems, the present analysis establishes a relationship between the precisely defined Voronoi free volume (information) entropy and the thermodynamic entropy. This analysis also shows that the max-ent formalism, when applied to the free volume entropy, predicts an exponential distribution which is approached by disordered states generated by a swelling algorithm in the dense random-packing limit.

Network of cytokines, integrins and hormones in human trophoblast cells.

Trophoblast cells of the developing embryo are unique not only for transporting oxygen and nutrients from the mother to the fetus but also for their array of other functions throughout the pregnancy beginning from the attachment of the blastocyst to the endometrium during the process of implantation, its well regulated invasion in the uterine tissue, proliferation, differentiation and immuno-endocrine functions which subsequently maintain the pregnancy. Using human trophoblast cells in culture, we have tried to understand the molecular mechanisms which regulate such a variety of functions for trophoblast cells. Our RT-PCR studies show that trophoblast cells express the laminin and collagen receptors: integrins alpha1 and alpha2, which are both stimulated by IL-1 and IL-6. These two cytokines, also synthesised by the trophoblast cells themselves, act in an autocrine/paracrine manner to induce their own expression. In addition, IL-1 expression seems to be modulated by a large variety of cytokines and growth factors usually present in the uterine milieu whereas IL-6 expression appears to be significantly stimulated by growth factors like EGF and bFGF only. Hormones like estrogen, progesterone and hCG exhibit a general negative modulation in the expression of IL-1 and IL-6. Since, both IL-1 and IL-6 are known to be involved in the proliferation, invasion and differentiation of trophoblast cells, they might be the key factors involved in trophoblast functions.