Experimental study of the strength characteristics of fixation of the symphysis pubis with an original plate for the reconstruction of the anterior pelvic semi-ring

The destabilization of bone fixators has led to repeated surgical interventions that increased the risk of migrations of metal fixators, infectious and inflammatory complications as well. The modern trends in hip bone injury surgery are related to developing and using of metal fixators, which are effective in acute injury; however, sometimes the condition of the patient and the technical support of hospitals don’t allow performing surgery in the acute period, and these metal fixators are ineffective for chronic damage. Consequently, until now, the problem of finding the optimal design of structures for fixing chronic damage of anterior pelvic semi-ring which will be able to exclude its destabilization, is still of current interest.The purpose of the study: developing and experimental researching of durable features of original plate for reconstruction of the anterior pelvic semi-ring.Materials and methods: In order to ensure stable fixation of chronic pelvic injuries, the original metal plates have been worked out. They are made individually in accordance with the anatomical and functional structures of the anterior pelvic semi-ring of the patient with using additive technologies. The study of the reliability of the different variants of ostiosynthesis of the anterior pelvic semi-ring with using well-known pelvic plates and a new original design was carried out. Stability tests for different plate fixing methods and mechanical strength of metallophyxators were carried out on a universal test machine of LFM-50kN series.Results: one plate fixation in tensile test showed the lowest result – 0.341 kN, a low result of shear loads was received with the same object. The best result was shown by the polyaxial monolithic plate fixation in case of stretching – 0.51 kN at the shear loads – 0.591 kN. Necessary force applied to destabilizing of the metal structure while using a polyaxial monolithic plate was a half-higher than stretched, and a third higher than at shear loads, it demonstrates the benefits of using these metal fixators.Conclusion: It is experimentally confirmed that the polyaxial monolithic plate provides the highest stability of fixing anterior pelvic semi-ring indicator in contrast with fixing of one or two plates.

Download Full-text

Problems of surgical treatment of the anterior pelvic ring chronic injuries

Practical medicine ◽

10.32000/2072-1757-2021-3-47-54 ◽

2021 ◽

Vol 19 (3) ◽

pp. 47-54

Author(s):

A. F. LAZAREV ◽

◽

E. I. SOLOD ◽

YA. G. GUDUSHAURI ◽

E. I. KALININ ◽

...

Keyword(s):

Surgical Treatment ◽

Pelvic Ring ◽

Metal Structure ◽

Complex Problem ◽

Long Term Results ◽

Fixation Method ◽

Surgical Interventions ◽

Anterior Section ◽

Pelvic Injuries ◽

Study Results

A surgical treatment of the joints of the pelvic ring, especially the pubic joint is a separate and complex problem. When using standard plates, which are applied in the treatment of patients with fresh injuries to stabilize old injuries of the pelvic ring, problems arise with fatigue fracture of plates, destabilization of the metal structure and the need for repeated surgical interventions. Therefore, in the case of old injuries, during surgical treatment, it is necessary to use other tactical approaches to fixing pelvic injuries and to search for adapted structures for such cases. The purpose — to study the features of fixation of old injuries of the pelvic ring and to determine the results of different methods of the anterior pelvis fixation in old cases. Materials and methods. A retrospective analysis of the performed surgical treatment was carried out. In 2000-2015, in the first department of National Medical Research Center of Traumatology and Orthopedics named after N.N. Priorov, 117 patients underwent surgical treatment of old injuries of the anterior pelvic ring under our supervision using standard reconstructive plates applied in the surgical treatment of new injuries of the pelvic ring. Results. Of the 65 patients who underwent fixation of an old injury of the anterior semiring with AO reconstructive plates and AO pelvic plates, installed in a standard manner as in new injuries, 12 patients (10,2%) experienced migration or fracture of structures within 2 to 6 months from the operation. In 52 patients, fixation of the anterior section with two AO plates was applied, one of which was located in a standard way along the upper edge of the pubic bones, the second was implanted additionally along the anterior surface of the pelvic ring perpendicular to the first one. In this group, migration and destabilization of the structures was observed in 7 patients (13,4%) within a period from 2 weeks to 2 months from the date of the operation. Conclusion. The analysis of the study results suggests that surgical treatment of old injuries of the anterior pelvic ring requires a special approach to the choice of the surgical fixation method, which differs from the treatment of new injuries. Over time, in the absence of treatment for injuries and ruptures of the pelvic ring, cicatricial-fibrous adhesions of the pelvic ring occur, which does not always ensure the stability of the pelvic ring, but leads to rigid post-traumatic deformity of the pelvis. Taking into account the cases of destabilization in groups 1 — 10,2% and 2 — 13,4%, as well as the assessment of the long-term results according to the Majeed scale, the use of standard methods for fixing the anterior pelvic semiring can be considered ineffective in old pelvic injuries.

Download Full-text

Task based conceptual design of a testing machine

MATEC Web of Conferences ◽

10.1051/matecconf/201928701008 ◽

2019 ◽

Vol 287 ◽

pp. 01008

Author(s):

Hrayr Darbinyan

Keyword(s):

Conceptual Design ◽

Power Transmission ◽

Mechanical Design ◽

Design Method ◽

Testing Machine ◽

General Concept ◽

Test Machine ◽

Concept Design ◽

Original Design ◽

Design Cycle

A novel approach of task based conceptual design(TBCD) has been successfully used as direct guider and efficient developer of unique mechanical structures for many cases of mechanical design. Nearly a decade long efforts of elaboration of efficient every day usage formats for this method have been ended in convenient design pages suitable and applicable for revealing, describing, visualizing and managing the data necessary for organizing the design process from task definition to solutions satisfying original design tasks. The aim of current study is to show steps of a solution generation within frames of a single design cycle and extend this action over consecutive design cycles. Those steps are described from standpoint of general concept design method starting from key model and finished with final aggregation matrice as ultimate step of a single design cycle. Unified mathematical expressions are used for introduction and description of all worked out and developed components of conceptual design. The paper is arranged in a way to show gradual steps of conceptual design(CD) of a power transmission system – a pipe wrench life test machine.

Download Full-text

Box Plate Fixation of the Symphysis Pubis: Biomechanical Evaluation of a New Technique

Journal of Orthopaedic Trauma ◽

10.1097/00005131-199412000-00005 ◽

1994 ◽

Vol 8 (6) ◽

pp. 483-489 ◽

Cited By ~ 40

Author(s):

Peter T. Simonian ◽

M L Chip Routt ◽

Richard M. Harrington ◽

Allan F. Tencer

Keyword(s):

Plate Fixation ◽

Symphysis Pubis ◽

New Technique ◽

Biomechanical Evaluation ◽

A New Technique

Download Full-text

Is Fixation Failure After Plate Fixation of the Symphysis Pubis Clinically Important?

Clinical Orthopaedics and Related Research ◽

10.1007/s11999-012-2427-z ◽

2012 ◽

Vol 470 (8) ◽

pp. 2154-2160 ◽

Cited By ~ 27

Author(s):

Stephen A. C. Morris ◽

Jeremy Loveridge ◽

David K. A. Smart ◽

Anthony J. Ward ◽

Tim J. S. Chesser

Keyword(s):

Plate Fixation ◽

Symphysis Pubis ◽

Fixation Failure

Download Full-text

A comparison of percutaneous reduction and screw fixation versus open reduction and plate fixation of traumatic symphysis pubis diastasis

Archives of Orthopaedic and Trauma Surgery ◽

10.1007/s00402-011-1414-2 ◽

2011 ◽

Vol 132 (2) ◽

pp. 265-270 ◽

Cited By ~ 15

Author(s):

Linwei Chen ◽

Guoyou Zhang ◽

Dianwen Song ◽

Xiaoshan Guo ◽

Wen Yuan

Keyword(s):

Open Reduction ◽

Screw Fixation ◽

Plate Fixation ◽

Symphysis Pubis ◽

Percutaneous Reduction ◽

Symphysis Pubis Diastasis

Download Full-text

Development of a method and equipment for testing materials for alternating bending during piercing in screw rolling mills

Chernye Metally ◽

10.17580/chm.2020.11.04 ◽

2020 ◽

pp. 29-34

Author(s):

B. A. Romantsev ◽

◽

A. S. Aleshchenko ◽

E. R. Guseynov ◽

V. Yu. Tsyutsyura ◽

...

Keyword(s):

Deformation Zone ◽

Rolling Mill ◽

Pipe Production ◽

Test Machine ◽

Shell Wall ◽

Original Design ◽

Plastic Bending ◽

Deformed State ◽

Hot Rolled ◽

Alternating Bending

Hot-rolled pipe production is complicated process of metal treatment by pressure and as a rule it has three operations of form charging: piercing, plugging, calibration or reduction. Each of them is characterized by complex schemes of stress-deformed state which promotes either formation or detection of various defects. Hot billet piercing at screw piercing rolling mill is widely used for pipe production for its high output and getting the shells of long length. But this operation of form charging of the metal is realized under the conditions of complicated stress-deformed state with cyclic alternating bending of all metal layers. Defects appearing on the outside surface of the shell such as captures and cracks is caused by plastic bending of shell wall, which is followed by alternating stress and deformation at the inlet and outlet cone of deformation zone in consequence of four times plastic bending of the wall. Shell wall is influenced by compression stress of the working rolls and guides. The less favorable scheme of stress state with tensile stress arises on the shell surface between the rolls and the guide. And as a results it generates and increases the defects on the outside surface. Theoretical and experimental research of deformation and speed conditions of billet piercing process for screw piercing rolling mill is presented in the work. Statistic data of production mills which operate in TRA 50-200 and TRA 159-426 lines were used for the research. All the calculations were done with use of applied software and test machine of original design with crank and connecting rod mechanism was constructed. The machine carries out the process of alternating plastic bending which is in maximum close to the conditions taking place in deformation zone of screw piercing rolling mill. Definition of rational configuration of sample shape was determined. Process plasticity of the metal of hot samples was analyzed as well. The samples were made from hot-rolled bars of different steel grades.

Download Full-text

PLATE FIXATION OF DISRUPTED SYMPHYSIS PUBIS

Journal of Bone and Joint Surgery - British Volume ◽

10.1302/0301-620x.55b3.618 ◽

1973 ◽

Vol 55-B (3) ◽

pp. 618-620 ◽

Cited By ~ 18

Author(s):

Ian K. Sharp

Keyword(s):

Plate Fixation ◽

Symphysis Pubis

Download Full-text

Mini-plate fixation via sinus tarsi approach is superior to cannulated screw in intra-articular calcaneal fractures: A prospective randomized study

Journal of Orthopaedic Surgery ◽

10.1177/2309499018792742 ◽

2018 ◽

Vol 26 (3) ◽

pp. 230949901879274 ◽

Cited By ~ 3

Author(s):

Mustafa C Kir ◽

Semih Ayanoglu ◽

Haluk Cabuk ◽

Suleyman S Dedeoglu ◽

Yunus Imren ◽

...

Keyword(s):

Plate Fixation ◽

Randomized Study ◽

Cannulated Screw ◽

Final Visit ◽

X Rays ◽

Calcaneal Fractures ◽

Surgical Interventions ◽

Sinus Tarsi ◽

Sinus Tarsi Approach ◽

Mini Plate

Objective: Intra-articular displaced calcaneal fractures are common fractures and are often treated with surgical interventions. Sinüs tarsi approach provides secure access to lateral wall and joint facets. The aim of the study is to compare cannulated screw (CS) fixation and mini-plate (MP) fixation via sinus tarsi approach with Sanders types 2 and 3 fracture of calcaneus. Methods: Sixty patients with Sanders types 2 and 3 calcaneal fracture underwent surgical intervention were randomly allocated into two groups as group MP fixation and group CS fixation regarding osteosynthesis method for 5-year period. Open reduction via sinüs tarsi approach was performed in both groups. Demographic variables, time to surgery (TS), operation duration (OD), length of hospital stay (LOS), surgical complications, and reoperations were recorded. Pre- and postoperative Gissane and Böhler angles; calcaneal length, height, and width; ankle anterior-posterior (AP) and lateral X-rays; and computed tomography were also recorded for radiological evaluation and fracture characteristics. Maryland Foot Score (MFS) was used to evaluate functional outcomes. Results: Preoperative age, type of fracture, calcaneal length, height, and Gissane and Böhler angles, TS, LOS, and OD were not different between the groups. The postoperative calcaneal widening was significantly better restored in group MP compared with that of group CS. The incidence of reoperation and algoneurodystrophy was statistically higher in group CS than group MP. MFS in group MP was also higher than group CS at final visit. Conclusion: MP fixation via sinus tarsi approach is superior to CS fixation in Sanders types 2 and 3 calcaneal fractures.

Download Full-text