Complete enucleation of a complicated solid pseudopapillary neoplasm of pancreas: A case report.

INTRODUCTION: Solid pseudopapillary neoplasm (SPN) of the pancreas is a rare pancreatic tumor, usually affecting young females. It is categorized as a low-grade malignant tumor without any specific epithelial differentiation, which can occur anywhere in the pancreas. CASE PRESENTATION: Here, we present the case of a 35-year-old lady who presented to us with abdominal pain and a pancreatic mass. She had a prior laparotomy at a different center without any specific intervention for the lump. After presenting to our center, she was managed through proper evaluation and adequate preparation for surgery. The diagnosis was challenging, and so was the surgery. We had enucleated the lesion completely. Histopathology confirmed the diagnosis of SPN. There are no signs of recurrence after two years. DISCUSSION: Patients are either asymptomatic or usually present with abdominal pain, a large abdominal lump, or some vague symptoms. A high index of suspicion is the key to diagnosis. Complete resection is the gold standard of treatment. Enucleation is also a good option in difficult cases. The prognosis after surgery is excellent. CONCLUSION: Total enucleation of the SPN of the pancreas is a reasonable alternative in selected cases when performed by experienced hepatobiliary-pancreatic surgeons.

Biomechanical optimization of the far cortical locking technique for early healing of distal femur fractures.

This finite element study optimized far cortical locking (FCL) technology for early callus formation in distal femur fracture fixation with a 9-hole plate using FCL screws proximal to, and standard locking screws distal to, the fracture. Analyses were done for 120 possible FCL screw configurations by varying FCL screw distribution and number. A hip joint force of 700 N (i.e. 100% x body weight) was used, which corresponds to a typical 140 N "toe-touch" foot-to-ground force (i.e. 20% x body weight) suggested to patients immediately after surgery. Increased FCL screw distribution (i.e. shorter plate working length) caused a decrease at the medial side and an increase at the lateral side of the axial interfragmentary motion (AIM), mildly affected shaft and condylar cortex Von Mises max stress (σMAX), increased plate σMAX, and decreased shaft FCL screw and condylar locking screw σMAX. Increased FCL screw number decreased AIM and σMAX on the shaft cortex, condylar cortex, plate, and FCL screws, but not condylar screws. The optimal FCL screw configuration had 3 FCL screws in plate holes #1, 5, and 6 (proximal to distal) for optimal AIM of 0.2 - 1 mm and reduce shear fracture motion, thereby encouraging early callus formation.

Mechanical characterization of the static and fatigue compressive properties of a new glass/flax/epoxy composite material using digital image correlation, thermographic stress analysis, and conventional mechanical testing.

This study characterized the static and fatigue compressive properties of a new hybrid composite material made of synthetic and natural fibers with an epoxy matrix. The glass/flax/epoxy composite material was manufactured as a "sandwich structure" with a Type A configuration (i.e. [0G2/0F12/0G2] using unidirectional glass (G) and flax (F) fibers) and Type B configuration (i.e. [0G2/±45F12/0G2] using unidirectional glass (G) and ±45° oblique flax (F) fibers). Digital image correlation was used to obtain the static properties of compressive elastic modulus (Type A, 24.4 GPa; Type B, 14.7 GPa), ultimate compressive strength (Type A, 261.7 MPa; Type B, 231.9 MPa), and Poisson's ratio (Type A, 0.37; Type B, 0.58). Thermographic stress analysis was used to measure a high cycle fatigue strength (HCFS) of 53% (Type A and B) of ultimate compressive strength. Conventional experimental fatigue methods (i.e. stress vs. number of cycles to failure) yielded a HCFS of 56-61% (Type A) and 51-56% (Type B), as well as almost constant dynamic compressive moduli of 15 GPa (Type A) and 10 GPa (Type B) over the entire loading regime. This new composite material may have various potential applications, such as aerospace, automotive, biomechanics, sports, etc., based on the compressive properties measured.

Biomechanical Measurement Error Can Be Caused by Fujifilm Thickness: A Theoretical, Experimental, and Computational Analysis.

This is the first study to quantify the measurement error due to the physical thickness of Fujifilm for several material combinations relevant to orthopaedics. Theoretical and experimental analyses were conducted for cylinder-on-flat indentation over a series of forces (750 and 3000 N), cylinder diameters (0 to 80 mm), and material combinations (metal-on-metal, MOM; metal-on-polymer, MOP; metal-on-bone, MOB). For the scenario without Fujifilm, classic Hertzian theory predicted the true line-type contact width as WO = {(8FDcyl)/(πLcyl)[(1 - νcyl2)/Ecyl + (1 - νflat2)/Eflat]}1/2, where F is compressive force, Dcyl is cylinder diameter, Lcyl is cylinder length, νcyl and νflat are cylinder and flat Poisson's ratios, and Ecyl and Eflat are cylinder and flat elastic moduli. For the scenario with Fujifilm, experimental measurements resulted in contact widths of WF = 0.1778 × F0.2273 × D0.2936 for MOM tests, WF = 0.0449 × F0.4664 × D0.4201 for MOP tests, and WF = 0.1647 × F0.2397 × D0.3394 for MOB tests, where F is compressive force and D is cylinder diameter. Fujifilm thickness error ratio WF /WO showed a nonlinear decrease versus cylinder diameter, whilst error graphs shifted down as force increased. Computational finite element analysis for several test cases agreed with theoretical and experimental data, respectively, to within 3.3% and 1.4%. Despite its wide use, Fujifilm's measurement errors must be kept in mind when employed in orthopaedic biomechanics research.