scholarly journals Removal of locking plates: new implant, new challenges and new solutions

2011 ◽  
Vol 1 (2) ◽  
pp. 25
Author(s):  
Bhavuk Garg ◽  
Tarun Goyal ◽  
Vijay Kumar ◽  
Rajesh Malhotra ◽  
Prakash P. Kotwal
Keyword(s):  
Locking Plate ◽  
Perioperative Complications ◽  
Point Of View ◽  
Locking Plates ◽  
Screw Head ◽  
Plate Removal ◽  
Novel Technique ◽  
Initial Surgery ◽  
New Challenges ◽  
Locking Screw

Removal of locking plates in many ways poses novel challenges compared to conventional plates. None of the techniques described for the removal of locking plates are adequate for all situations. We report our experience of 27 patients from whom a total of 33 locking plates were removed. We also describe a novel technique for the removal of locking plates which in our experience could be used in most of these patients because it is appropriate for all situations and, from a technical point of view, is easy to use. Our new technique consists of removing the problematic locking screw by cutting the plate on both sides of the screw hole and using the screw head-plate hole unit for removal. We analyzed all these patients for the location of the plate, number of locking screws, time of implant removal since the initial surgery, reason for removal of the plate, nature of the difficulties encountered during surgery, and any perioperative complications. A total of 43 (17.34%) screws were difficult to remove. Twenty screws were found to be stripped, 15 were jammed and 8 were broken. Fourteen of the 20 stripped screws and all 15 jammed screws were removed using our technique. We found this technique of locking plate removal to be very versatile and useful in most of the cases in which removal was difficult. At the same time, it also causes less damage to the bone compared to other techniques.

scholarly journals Temporal Changes in Reverse Torque of Locking-Head Screws Used in the Locking Plate in Segmental Tibial Defect in Goat Model

2021 ◽  
Vol 8 ◽  
Author(s):  
Remigiusz M. Grzeskowiak ◽  
Rebecca E. Rifkin ◽  
Elizabeth G. Croy ◽  
Richard C. Steiner ◽  
Reza Seddighi ◽  
...  
Keyword(s):  
Locking Plate ◽  
Segmental Bone Defect ◽  
Stable Fixation ◽  
Plate Removal ◽  
Locking Screws ◽  
Reverse Torque ◽  
Segmental Bone ◽  
Locking Screw ◽  
With Screws ◽  
Over Time

The objective of this study was to evaluate changes in peak reverse torque (PRT) of the locking head screws that occur over time. A locking plate construct, consisting of an 8-hole locking plate and 8 locking screws, was used to stabilize a tibia segmental bone defect in a goat model. PRT was measured after periods of 3, 6, 9, and 12 months of ambulation. PRT for each screw was determined during plate removal. Statistical analysis revealed that after 6 months of loading, locking screws placed in position no. 4 had significantly less PRT as compared with screws placed in position no. 5 (p < 0.05). There were no statistically significant differences in PRT between groups as a factor of time (p > 0.05). Intracortical fractures occurred during the placement of 151 out of 664 screws (22.7%) and were significantly more common in the screw positions closest to the osteotomy (positions 4 and 5, p < 0.05). Periosteal and endosteal bone reactions and locking screw backout occurred significantly more often in the proximal bone segments (p < 0.05). Screw backout significantly, negatively influenced the PRT of the screws placed in positions no. 3, 4, and 5 (p < 0.05). The locking plate-screw constructs provided stable fixation of 2.5-cm segmental tibia defects in a goat animal model for up to 12 months.

scholarly journals Biomechanical comparison of two locking plate constructs under cyclic torsional loading in a fracture gap model

2015 ◽  
Vol 28 (05) ◽  
pp. 323-330 ◽  
Author(s):  
A. Bilmont ◽  
S. Palierne ◽  
M. Verset ◽  
P. Swider ◽  
A. Autefage
Keyword(s):  
Locking Plate ◽  
Torsional Loading ◽  
Screw Head ◽  
The Third ◽  
Cyclic Torsion ◽  
Locking Screws ◽  
Locking Compression Plates ◽  
Number Of Cycles ◽  
Biomechanical Comparison ◽  
Locking Screw

SummaryObjectives: The number of locking screws required per fragment during bridging osteo-synthesis in the dog has not been determined. The purpose of this study was to assess the survival of two constructs, with either two or three screws per fragment, under cyclic torsion.Methods: Ten-hole 3.5 mm stainless steel locking compression plates (LCP) were fixed 1 mm away from bone surrogates with a fracture gap of 47 mm using two bicortical locking screws (10 constructs) or three bicortical locking screws (10 constructs) per fragment, placed at the extremities of each LCP. Constructs were tested in cyclic torsion (range: 0 to +0.218 rad) until failure.Results: The 3-screws constructs (29.65 ± 1.89 N.m/rad) were stiffer than the 2-screws constructs (23.73 ± 0.87 N.m/rad), and therefore, were subjected to a greater torque during cycling (6.05 ± 1.33 N.m and 4.88 ± 1.14 N.m respectively). The 3-screws constructs sustained a significantly greater number of cycles (20,700 ± 5,735 cycles) than the 2-screws constructs (15,600 ± 5,272 cycles). In most constructs, failure was due to screw damage at the junction of the shaft and head. The remaining constructs failed because of screw head unlocking, sometimes due to incomplete seating of the screw head prior to testing.Clinical significance: Omitting the third innermost locking screw during bridging osteosynthesis led to a reduction in fatigue life of 25% and construct stiffness by 20%. Fracture of the screws is believed to occur sequentially, starting with the innermost screw that initially shields the other screws.

scholarly journals Single-Step Renal Dilatation Is a Novel Technique in Percutaneous Nephrolithotomy: A Prospective Randomised Study

2020 ◽  
Vol 20 (2) ◽  
pp. 70-73
Author(s):  
Md Shariful Islam ◽  
Md Shawkat Alam ◽  
AHM Mostofa Kamal ◽  
Md Asaduzzamman ◽  
Md Ruhul Quddus
Keyword(s):  
Percutaneous Nephrolithotomy ◽  
Perioperative Complications ◽  
Single Step ◽  
Safety And Efficacy ◽  
X Ray ◽  
Randomised Study ◽  
Operative Duration ◽  
Novel Technique ◽  
Significant Difference ◽  
Prospective Randomised Study

Purpose: To evaluate the feasibility, safety and efficacy of one-shot dilation (OSD) in percutaneous nephrolithotomy (PCNL). Materials and Methods: In a prospective randomised study including 62 patients divided into two groups, the first had RD before PCNL using the standard metallic telescopic dilators (Alken), and the second had RD using the 30-F Amplatz dilator over the central Alken dilator. The operative duration, with X-ray exposure, was calculated. The procedure outcome in terms of complications, stone-free rates and hospital stay was evaluated statistically. Results : The tract was dilated correctly in all cases. The operative duration and X-ray exposure was shorter in patients undergoing single-step RD (P < 0.05). There were perioperative complications, according to the Clavien grading system, in 15 (25%) patients but there was no statistically significant difference between the groups. The stone-free rates were comparable in both groups. Conclusion : A single-step RD during PCNL is feasible, with a shorter operative duration and X-ray exposure. The outcomes were comparable with those of a standard metallic telescopic RD Bangladesh Journal of Urology, Vol. 20, No. 2, July 2017 p.70-73

scholarly journals Book review: “Corporate governance: New challenges and opportunities”

2018 ◽  
Vol 14 (1) ◽  
pp. 57-58
Author(s):  
Alessio M. Pacces ◽  
Laurent Germain ◽  
Áron Perényi
Keyword(s):  
Corporate Governance ◽  
Point Of View ◽  
Challenges And Opportunities ◽  
New Challenges

This review covers the book titled “CORPORATE GOVERNANCE: NEW CHALLENGES AND OPPORTUNITIES”, which was written by Alexander N. Kostyuk, Udo Braendle and Vincenzo Capizzi (Virtus Interpress, 2017, Hardcover, ISBN: 978-617-7309-00-9). The review shortly outlines the structure of the book, pays attention to it’s strong sides and issues that will be, by the reviewers’ point of view, most interesting for the reader.

Covariance estimation using random permutations

2018 ◽  
Vol 05 (01) ◽  
pp. 1850005
Author(s):  
Lakshmi Padmakumari ◽  
S. Maheswaran
Keyword(s):  
Relative Efficiency ◽  
Covariance Estimation ◽  
Point Of View ◽  
Random Permutations ◽  
Sample Period ◽  
Novel Technique ◽  
Stock Indices ◽  
Covariance Estimator ◽  
Exchange Effects ◽  
Correlated Assets

This paper explores a novel technique to compute the level of covariance between any two genuinely correlated assets by adopting the idea of random permutations by proposing an unbiased covariance estimator “[Formula: see text]” based on daily high-low prices. The main goal is to boost the relative efficiency of the estimator by increasing the number of random permutations. We validate this claim with the help of simulations later. Further, we prove theoretically and through simulations that the proposed estimator is unbiased for a pair of random walks. Upon empirically implementing the estimator in a dataset of three sets of stock indices: Nifty, FTSE100 and S&P500 after accounting for exchange effects (USDINR and GBPINR) over a sample period of 252 months (Jan 1996–Dec 2016), we do not find evidence of any bias in the estimator. Also, there is a visible asymmetry in the correlation between US-Indian markets from the two investor’s point of view.

Ontological Dimensions of Semantic Mobile Web 2.0

2011 ◽  
pp. 667-688
Author(s):  
Gonzalo Aranda-Corral ◽  
Joaquín Borrego-Díaz
Keyword(s):  
Social Networks ◽  
Semantic Web ◽  
Knowledge Representation ◽  
Web 2.0 ◽  
Point Of View ◽  
Knowledge Representation And Reasoning ◽  
Mobile Web ◽  
New Knowledge ◽  
New Challenges

In this chapter, we advance, from the point of view of Knowledge Representation and Reasoning, an analysis of which ontological dimensions are needed to develop Mobile Web 2.0 on top of Semantic Web. This analysis will be particularly focused on social networks and it will try to make an outlook about the new knowledge challenges on this field. Some of these new challenges will be linked to Semantic Web context, while others will be inherent to Semantic Mobile Web 2.0.

Sign in / Sign up

Export Citation Format

Share Document