Evaluation of wave configurations in corrugated boards by experimental analysis (EA) and finite element modeling (FEM): the role of the micro-wave in packaging design.

The aim of this paper is to study the mechanical behavior of corrugated board boxes, focusing attention on the strength that the boxes are able to offer in compression under stacking conditions. A preliminary design of the corrugated cardboard structures starting from the definition of each individual layer, namely the outer liners and the innermost flute, was carried out. For this purpose, three distinct types of corrugated board structures that include flutes with different characteristics, namely the high wave (C), the medium wave (B), and even the micro-wave (E), were comparatively evaluated. More specifically, the comparison is able to show the potential of the micro-wave which would eventually allow a significant saving of cellulose in the fabrication process of the boxes, thus reducing the manufacturing costs and causing a lower environmental footprint. First, experimental tests were carried out to determine the mechanical properties of the different layers of the corrugated board structures. Tensile tests were performed on samples extracted from the paper reels used as base material for the manufacturing of the liners and flutes. Instead, the edge crush test (ECT) and box compression test (BCT) were directly performed on the corrugated cardboard structures. Secondly, a parametric finite element (FE) model to allow, on a comparative basis, the study of the mechanical response of the three different types of corrugated cardboard structures was developed. Lastly, a comparison between the available experimental results and the outputs of the FE model was carried out, with the same model being also adapted to evaluate additional structures where the E micro-wave was usefully combined with the B or C wave in a double-wave configuration.

Human Amniotic Membrane Wrapping of the Ulnar Nerve During Cubital Tunnel Surgery Reduces Recurrence of Symptoms.

Background: Compare the recurrence rate of paresthesias in patients undergoing primary cubital tunnel surgery in those with and without wrapping of the ulnar nerve with the human amniotic membrane (HAM). Methods: A retrospective investigation of patients undergoing primary cubital tunnel surgery with a minimum 90-day follow-up was performed. Patients were excluded if the nerve was wrapped using another material, associated traumatic injury, simultaneous Guyon's canal release, or revision procedures. Failure was defined as those patients who experienced initial complete resolution of symptoms (paresthesias) but then developed recurrence of paresthesias. Results: A total of 57 controls (CON) and 21 treated with HAM met our inclusion criteria. There was a difference in the mean age of CON (48.4 ± 13.5 years) and HAM (30.6 ± 15) (P< 0.0001). There was no difference in gender mix (P=0.4), the severity of symptoms (P=0.13), and length of follow-up (P=0.084). None of 21 (0%) treated with HAM developed recurrence of symptoms compared to 11 of 57 (19.3%) (P=0.03) (CON). Using a multivariate regression model adjusted for age and procedure type, CON was 24.4 (95% CI=1.26-500, P=0.0348) times higher risk than HAM of developing a recurrence of symptoms. Conclusion: The HAM wrapping used in primary cubital tunnel surgery significantly reduced recurrence rates of paresthesias. Further prospective studies with randomization should be carried out to better understand the role HAM can play in cubital tunnel surgery.

Characteristics of Iatrogenic Nerve Injury from Orthopedic Surgery Correlate with Time to Subspecialty Presentation.

There is no current literature examining iatrogenic nerve injury resulting from orthopedic procedures across subspecialties and anatomic areas. This study uses a single peripheral nerve surgeon's experience to investigate the variable time to presentation of adult patients with iatrogenic nerve injury after orthopedic surgery. METHODS: A retrospective review of patients examined in Peripheral Nerve Clinic (PNC) from January 1, 2012, to April 1, 2018, at a single, private, university hospital was performed. Fifty-eight adult patients met inclusion criteria. Charts were reviewed to determine the index orthopedic procedure, peripheral nerve affected, clinical deficits, patient demographics, and time from injury to PNC presentation. RESULTS: The average patient age was 51.2 years, and the average time to PNC referral was 10.9 months after the procedure that resulted in nerve injury. The orthopedic procedures included fracture fixation (13), joint arthroplasty (10) knee arthroscopy and ligament reconstruction (9), mass excision (9), shoulder arthroscopy (7), irrigation and debridement (2), removal of deep hardware (2), tendon procedures (2), trigger digit release (2), nerve decompression (1), and release of exertional compartment syndrome (1). Time from injury to PNC presentation was substantially shorter for patients with upper extremity versus lower extremity deficits (5.9 months vs 19.8 months; P = 0.0173) and for patients with motor nerve involvement versus those with isolated sensory nerve injury (4.5 months vs 24.3 months; P = 0.0164). CONCLUSIONS: Iatrogenic nerve injury is a risk across orthopedic subspecialties. Nerve injuries in the lower extremity and those with isolated sensory deficits have significantly delayed time to subspecialty presentation.

Dataset of biogenic crusts from submarine caves of the Aegean Sea: An example of sponges vs microbialites competition in cryptic environments.

This dataset aims at illustrating the relationships between Metazoa and Bacteria in confined environments. For this purpose, the biotic crusts inside two submarine caves of the Aegean Sea were examined in order to characterize organisms involved in their formation. The present manuscript provides additional data and information to our research article "Composition and biostratinomy of sponge-rich biogenic crusts in submarine caves (Aegean Sea, Eastern Mediterranean)" [1] (Guido et al.). The data were collected with an integrated approach utilizing microfacies observations in optical microscopy and micromorphological and geochemical characterization in electron microscopy (SEM and EPMA). We present here microfacies showing the boundstone framework, which is rich in microcavities partly filled by sponge spicules and scant autochthonous micrite. SEM and EPMA data put in evidence the abundance of sponge spicules inside the crusts and allow discriminating between two types of micrite: detrital micrite and autochthonous micrite. The data presented in this article and those described in Guido et al. [1] allow the evaluation of the relationship between sponges and carbonatogenetic bacteria in the cryptic conditions of submarine caves, and provide new knowledge to interpret the fossil record.

Medial Patellofemoral Ligament Reconstruction: Fixation Technique Biomechanics.

Introduction The medial patellofemoral ligament (MPFL) is the primary soft-tissue stabilizer of the patella and it is often reconstructed in patients with recurrent patella instability. This biomechanical analysis evaluates the integrity of four methods of MPFL reconstruction subjected to cyclic loading using a porcine model. Methods Four techniques of MPFL reconstruction were analyzed using a 4 mm flexor tendon graft, all with two points of patellar fixation to best recreate the native MPFL anatomy. The four techniques were: (1) interference screw technique, (2) suture anchor technique, (3) converging tunnel technique, and (4) two bone tunnel technique. Maximum load, yield load, and stiffness of the graft fixation/bone complex were analyzed, and statistics were performed with SPSS and significance set at a p-value of < 0.05. Results The converging tunnel technique demonstrated the highest maximum load and yield load, significantly higher than the interference screw or suture anchor groups (p = 0.007). In addition, the converging tunnel technique demonstrated the greatest stiffness with significantly greater stiffness than the two bone tunnel techniques (p = 0.016). Conclusion The combination of strength and stiffness, the avoidance of patella implants, and the creation of a single transosseous tunnel make the converging tunnel technique a desirable technique for MPFL reconstructions.

Salter-Harris II fractures of the distal tibia: does surgical management reduce the risk of premature physeal closure?

INTRODUCTION: Premature physeal closure (PPC) is a common complication resulting from the management of a displaced Salter-Harris II (SH II) fracture of the distal tibia. The purpose of this study was to evaluate our institution's treatment approach to assess PPC and complication rates of fractures treated both surgically and nonsurgically. METHODS: We performed a retrospective review of all patients presenting with a displaced SH II fracture between 2004 and 2010. Initial treatment was closed reduction in the emergency department. Further treatment and subsequent categorization was based on amount of residual displacement. Patients with <2 mm of postreduction displacement were treated with a non-weight-bearing long-leg cast (LLC; group 1), patients with residual displacement between 2 and 4 mm were treated with one of 2 approaches based on surgeon preference: either LLC (group 2) or open reduction and internal fixation (ORIF) with removal of any interposed tissue (group 3). Patients with >4 mm of residual displacement were treated with ORIF (group 4). Follow-up radiographs were performed for a minimum of 6 months. If there was clinical concern about PPC, computed tomography imaging was performed to assess for a bony bar. RESULTS: In total, 96 patients with a mean age of 12.6 years at presentation were included in the study. Among the 14 patients with <2 mm of postreduction displacement, 29% had a PPC and 7% had to undergo a subsequent procedure (epiphsyiodesis, osteotomy, etc.). Of the 33 patients with 2 to 4 mm of displacement who were treated with a LLC, 33% had a PPC and 15% had to undergo a subsequent procedure. Of the 11 patients with 2 to 4 mm of displacement treated with ORIF 46% had a PPC and 18% had a second procedure. Finally, 38 patients with >4 mm of displacement treated with ORIF had a PPC rate of 55% and 23% had a subsequent procedure. No statistical differences in PPC (P=0.19) or subsequent surgeries (P=0.57) were observed between groups. Among those with 2 to 4 mm of postreduction displacement, patient age (P=0.36), sex (P=0.39), mechanism of injury (P=0.13), time to fracture management (P=0.51), amount of initial displacement (P=0.34), number of reduction attempts (P=0.43), and operative treatment (P=0.47) did not significantly influence PPC. CONCLUSIONS: Patients with displaced SH II distal tibia fractures pose a challenging problem for the treating physician with a high rate of PPC (43% overall). Although surgical fixation with anatomic reduction and removal of interposed tissue may be necessary to improve joint alignment, it does not reduce the incidence of PPC and may increase the need for subsequent surgeries.

The self-locating catheter: clinical experience and follow-up.

BACKGROUND: The self-locating catheter invented by Nicola Di Paolo has been used increasingly in Italy and elsewhere since 1994, with about a thousand patients currently implanted every year. Twelve grams of tungsten inserted into the tip of the conventional Tenckhoff catheter during extrusion does not significantly change its form, but suffices to keep the tip firmly in the Douglas cavity. OBJECTIVE: The aim of the present study was to confirm our preliminary results in a large population of peritoneal dialysis patients. SETTING: 16 Italian nephrology departments. RESULTS: In addition to confirming the validity of the new catheter, the present results show that patients with the new catheter have fewer episodes of peritonitis, tunnel infection, cuff extrusion, catheter malfunction, obstruction, and leakage. CONCLUSION: The present multicenter control study confirms preliminary results and demonstrates that complications of peritoneal dialysis, such as cuff extrusion, infection, peritonitis, early leakage, and obstruction, are statistically less frequent in patients with self-locating catheters than in patients with classic Tenckhoff catheters.