Mechanical Stability of a Locked Step-Plate versus Single Compression Screw Fixation for Medial Displacement Calcaneal Osteotomy

2012 ◽  
Vol 33 (8) ◽  
pp. 669-674 ◽  
Author(s):  
Sujith Konan ◽  
Jay Meswania ◽  
Gordon W. Blunn ◽  
Rohit T. Madhav ◽  
Michael J. Oddy
Keyword(s):  
Mechanical Stability ◽  
Screw Fixation ◽  
Plate Fixation ◽  
Cannulated Screw ◽  
Maximum Force ◽  
Plate Versus ◽  
Fixation Failure ◽  
Plate Interface ◽  
Displacement Osteotomy ◽  
Cadaveric Model

Background: Reconstruction of a flatfoot commonly involves a calcaneal Medial Displacement Osteotomy (MDO) to correct hindfoot valgus in combination with soft tissue procedures. We compared fixation of an MDO using either a single, large cannulated screw versus a locking step-plate in load to failure in a cadaveric model. Methods: Eight matched pairs of cadaveric limbs were loaded using a mechanical testing rig. Two pairs served as non-operated controls. The remaining paired limbs underwent a 10-mm MDO stabilized either with a single 7-mm screw or a step-plate with four locking screws. One pair was used as a pilot study and the remaining five pairs were loaded up to 4500 N to failure. Results: In the five pairs loaded to failure, the median (with 95% CI) maximum force were 1779 N (1099-2312) and 826 N (288-1607) for the plate and screw, respectively ( p = 0.043). With single screw fixation, the tuberosity fragment consistently failed by rotation and angulation into varus. With plate fixation, failure occurred as the screws cut through the internal surfaces of the tuberosity and body with no failure at the screw-plate interface. Conclusion: In this cadaveric model, a locked step-plate supported a significantly higher maximum force than a single large cannulated screw. Clinical Relevance: The magnitude of the load supported by the locking step-plate suggests that allowing early weightbearing post-operation may be safe in clinical practice before union of the osteotomy.

scholarly journals Percutaneous posterior transiliac plate versus iliosacral screw fixation for posterior fixation of Tile C-type pelvic fractures

2021 ◽  
Author(s):  
Chul-Ho Kim ◽  
Jung Jae Kim ◽  
Ji Wan Kim
Keyword(s):  
Bone Fractures ◽  
Screw Fixation ◽  
Plate Fixation ◽  
Surgical Techniques ◽  
Plate Versus ◽  
Pelvic Bone ◽  
Posterior Fixation ◽  
Iliosacral Screw ◽  
Plate Group ◽  
Spinopelvic Dissociation

Abstract Background: This study aimed to compare the clinical outcomes and complications between two minimally invasive surgical techniques: percutaneous transiliac plate fixation and iliosacral (IS) screw fixation for the treatment of Tile C-type pelvic bone fractures.Materials and Methods: We retrospectively reviewed the data of 77 consecutive patients with Tile C pelvic ring injuries who underwent either percutaneous transiliac plate fixation or IS screw fixation in a single academic center between November 2007 and January 2018. Posterior plating was indicated for those with sacral dysmorphism or bilateral sacral fractures, including spinopelvic dissociation. We recorded patients’ demographics, surgery-related data, and postoperative surgical outcomes and compared the incidence of complications and revision surgery rates between the two groups.Results: Overall, 14 patients were included in the plate group, while 63 were included in the IS screw fixation group. No significant differences were observed in the patients’ demographics between the two groups except for a longer interval from injury to surgery (13.5 days vs. 5.4 days, P = 0.001). Both groups acquired fracture union in all cases. There was one case of infection requiring surgical debridement in the plating group. Notably, nerve injury (n = 3) and implant loosening (n = 5) occurred in the IS screw group, but the difference was not significant.Conclusions: Both percutaneous posterior transiliac plating and IS screw fixation in patients with Tile C-type pelvic bone fractures showed good results. We recommend IS screw fixation as the primary treatment and propose posterior plating as treatment for sacral dysmorphism and bilateral sacral alar fractures in patients with spinopelvic dissociation.

scholarly journals Multiple Cannulated Screw Fixation of Femoral Neck Fractures with Comminution in Young and Middle Age Patients

2021 ◽  
Author(s):  
Zhe Han ◽  
Taxi Wumiti ◽  
Nengneng Ji ◽  
Xiang Sun ◽  
Chao Han ◽  
...  
Keyword(s):  
Postoperative Complications ◽  
Femoral Neck ◽  
Screw Fixation ◽  
Life Quality ◽  
Cannulated Screw ◽  
Occurrence Rate ◽  
Harris Hip Score ◽  
Fixation Failure ◽  
Aged Patients

Abstract Objective To investigate the distribution and influence of comminutions on femoral neck fracture (FNF) patients after cannulated screw fixation (CSF). Methods From January 2019 to June 2020, a total of 473 patients with FNF treated by CSF, aged 23–65 years, were included in present study. Based on location of the cortical comminution, the FNF patients were assigned as comminution group (anterior comminution, posterior comminution, superior comminution, inferior comminution, multiple comminutions) and without comminution group. The incidence of postoperative complications, quality of life and functional outcomes were recorded in different groups at 1 year-follow up. Results The comminution was more likely to appear in displaced FNF patients (86.8%) compared with non-displaced FNF patients (8.9%), while occurrence rate of comminution was also closely associated with Pauwels classification (3.2% vs 53.5% vs 83.9%, P<0.05). Besides, the incidence of osteonecrosis of femoral head (ONFH, 11.3% vs 2.9%, P<0.05), nonunion (7.5% vs 1.7%, P<0.05), femoral neck shortening (21.6% vs 13.4%, P<0.05) and internal fixation failure (11.8% vs 2.9%, P<0.05) in FNF patients with comminutions, especially with multiple comminutions, was significantly higher than those in FNF patients without comminution. Furthermore, there was a prominently difference in Harris hip score (HHS, 85.6±15.6 vs 91.3±10.8, P<0.05) and EuroQol five dimensions questionnaire (EQ-5D, 0.85±0.17 vs 0.91±0.18, P<0.05) score between FNF patients with comminution and FNF patients without comminution, whereas there was seem to be no significantly difference in Visual analogue scale (VAS, 1.46±2.49 vs 1.13±1.80, P>0.05) score between two groups at 1 year after surgery. Conclusion In our view, the comminution, easily happened in displaced FNF and Pauwel type III FNF, which was deemed to be a risk factor for postoperative complications in young and middle-aged patients underwent CSF, consequently causing an influence on recovery of hip function and life quality. However, further evaluation with better study design, larger sample and long-term follow-up was still imminently applied.

scholarly journals Biomechanical Analysis of the Tuning Fork Plate Versus Dual Pelvic Screws in a Sacrectomy Model: A Finite Element Study

2021 ◽  
pp. 219256822098379
Author(s):  
Amin Joukar ◽  
Jwalant Mehta ◽  
Vijay K. Goel ◽  
David S. Marks
Keyword(s):  
Finite Element ◽  
Tuning Fork ◽  
Screw Fixation ◽  
Plate Fixation ◽  
Biomechanical Analysis ◽  
Plate Versus ◽  
Element Analysis ◽  
Fixation Devices ◽  
Iliac Screw ◽  
Fixation System

Study Design: To evaluate the mechanical effectiveness of “tuning fork” plate fixation system by comparing with dual iliac screw fixation under different spinal motion through finite element analysis (FEA). Objective: Lumbosacral deficiencies occur from birth defects or following destruction by tumors. The objective of this study was to evaluate the mechanical effectiveness of the tuning fork plate compared to dual iliac screw system which is the gold standard fixation in treating lumbosacral deficiencies. This is an innovative fixation device for treating lumbosacral deficiencies. Methods: The deficiency model was prepared using a previously developed and validated finite element T10-pelvis model. To create the lumbo-sacral deficiency the segments between L3 and sacrum were removed from the model. The model was then instrumented from T10 to L2 segments and the ilium using either the tuning fork plate or a dual iliac screw construct. With the ilium fixed, the T10 vertebrae was subjected to 10 Nm moment and 400 N follower load to simulate spinal motions. Range of motion (ROM) of spine and stresses on the instrumentation were calculated for 2 fixation devices and compared with each other. Results: The 2 fixation systems demonstrate a comparable motion reduction in all loading modes. Stress values were higher in the dual iliac screw constructs compared with the tuning fork plate fixation system. The factor of safety of the tuning fork plate device was higher than the dual iliac screw fixation by 50%. Conclusions: Both fixation devices had similar performance in motion reduction at spine levels. However, based on predicted implant stresses there were less chances of implant failure in the fork plate fixation, compared to the dual iliac screw system.

A Biomechanical Evaluation of Three Forms of Internal Fixation Used in Ankle Arthrodesis

1994 ◽  
Vol 15 (6) ◽  
pp. 297-300 ◽  
Author(s):  
Michael P. Dohm ◽  
James B. Benjamin ◽  
Jeffrey Harrison ◽  
John A. Szivek
Keyword(s):  
Internal Fixation ◽  
Plate Fixation ◽  
Ankle Arthrodesis ◽  
Biomechanical Study ◽  
The Other ◽  
Fixation Failure ◽  
Plate Group ◽  
Biomechanical Evaluation ◽  
The Stability ◽  
Fibular Strut

A biomechanical study was undertaken to evaluate the relative stability of three types of internal fixation used for ankle arthrodesis. Crossed screw fixation, RAF fibular strut fixation, and T-plate fixation were tested in 30 cadaver ankles using an MTS machine. T-plate fixation consistantly provided the stiffest construct when compared with the other types of fixation. Failure occurred by distraction of bony surfaces, posterior to the plane of fixation, in the crossed screw and RAF groups. In contrast, failure in the T-plate group occurred through compression of bone anterior to the midcoronal plane of the tibia. Although the stability of fixation is only one factor in determining the success or failure of ankle arthrodesis, the results of this study would support T-plate fixation over the other forms tested.

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