Treatment of mechanically failed triple pelvic osteotomies in four dogs - part 2

2002 ◽  
Vol 15 (03) ◽  
pp. 172-176 ◽  
Author(s):  
S. Kerwin ◽  
G. Hosgood ◽  
R. D. Marquis ◽  
E. Pluhar ◽  
S. T. Kudnig ◽  
...  

SummaryFour dogs treated with triple pelvic osteotomies (TPOs) with loss of fixation secondary to screw loosening are reported. Two of the patients were revised with an additional ventral plate with successful outcomes. Revision TPO, with additional ventral plate fixation, was highly effective as a salvage technique for failed TPOs.

2002 ◽  
Vol 15 (03) ◽  
pp. 145-149 ◽  
Author(s):  
G. Hosgood ◽  
A. Staatz ◽  
R. B. Fitch

SummaryThe triple pelvic osteotomy (TPO) is commonly performed for immature dogs with hip dysplasia despite screw loosening being a prevalent complication. A technique to diminish the incidence of screw loosening by reducing motion at the ilial osteotomy and reducing implant migration, was evaluated. Standard triple pelvic osteotomies, and triple pelvic osteotomies with additional ventral plate stabilization, were performed and biomechanically evaluated in canine cadaver pelves. Additional ventral plate fixation was found to significantly improve axial bending stiffness of TPOs. In vitro cyclical loading, performed in a manner to approximate post-operative weight-bearing, determined that additional ventral plate fixation significantly decreased the incidence of screw loosening and motion at the osteotomy site.


2002 ◽  
Vol 15 (03) ◽  
pp. 164-171 ◽  
Author(s):  
S. Kerwin ◽  
G. Hosgood ◽  
M. Rooney ◽  
E. Pluhar ◽  
D. Pelsue ◽  
...  

SummaryTriple pelvic osteotomies (IPO) were evaluated in 40 clinical cases. In 39 cases, these were young dogs with hip dysplasia; in one case, the TPO was used as a correction for a hip luxation. Unilateral TPOs were performed in twenty patients, twelve with traditional TPO (without additional ventral plate) and eight with additional ventral plate fixation. Bilateral TPOs were performed in twenty patients, thirteen with traditional TPO and seven with additional ventral plate. In traditional TPOs, evidence of implant failure occurred in 5 of 12 unilateral and 11 of 13 bilateral procedures. In TPOs with additional ventral plate fixation, minor screw loosening was detected in one of eight unilateral and zero of seven bilateral procedures. Statistically TPOs without additional ventral plate fixation had 9.2 times greater odds of screw loosening with significantly greater acetabular segment displacement (p < 0.01). Two traditional TPOs performed required additional surgery due to screw loosening. Other attempted additional stabilization techniques used with the TPO procedure included ilial body wiring, ischial body wiring, sacral screw purchase, and medial screw nuts, however these methods did not prevent loosening and migration. TPO with additional ventral plate fixation was highly effective at combating implant failure.


Author(s):  
Michiel Herteleer ◽  
Mehdi Boudissa ◽  
Alexander Hofmann ◽  
Daniel Wagner ◽  
Pol Maria Rommens

Abstract Introduction In fragility fractures of the pelvis (FFP), fractures of the posterior pelvic ring are nearly always combined with fractures of the anterior pelvic ring. When a surgical stabilization of the posterior pelvis is performed, a stabilization of the anterior pelvis is recommended as well. In this study, we aim at finding out whether conventional plate osteosynthesis is a valid option in patients with osteoporotic bone. Materials and methods We retrospectively reviewed medical charts and radiographs of all patients with a FFP, who underwent a plate osteosynthesis of the anterior pelvic ring between 2009 and 2019. Patient demographics, fracture characteristics, properties of the osteosynthesis, complications and revision surgeries were documented. Single plate osteosynthesis (SPO) at the pelvic brim was compared with double plate osteosynthesis (DPO) with one plate at the pelvic brim and one plate anteriorly. We hypothesized that the number and severity of screw loosening (SL) or plate breakage in DPO are lower than in SPO. Results 48 patients with a mean age of 76.8 years were reviewed. In 37 cases, SPO was performed, in 11 cases DPO. Eight out of 11 DPO were performed in patients with FFP type III or FFP type IV. We performed significantly more DPO when the instability was located at the level of the pubic symphysis (p = 0.025). More patients with a chronic FFP (surgery more than one month after diagnosis) were treated with DPO (p = 0.07). Infra-acetabular screws were more often inserted in DPO (p = 0.056). Screw loosening (SL) was seen in the superior plate in 45% of patients. There was no SL in the anterior plate. There was SL in 19 of 37 patients with SPO and in 3 of 11 patients with DPO (p = 0.16). SL was localized near to the pubic symphysis in 19 of 22 patients after SPO and in all three patients after DPO. There was no SL in DPO within the first month postoperatively. We performed revision osteosynthesis in six patients (6/48), all belonged to the SPO group (6/37). The presence of a bone defect, unilateral or bilateral anterior pelvic ring fracture, post-operative weight-bearing restrictions, osteosynthesis of the posterior pelvic ring, and the presence of infra- or supra-acetabular screws did not significantly influence screw loosening in SPO or DPO. Conclusion There is a high rate of SL in plate fixation of the anterior pelvic ring in FFP. In the vast majority, SL is located near to the pubic symphysis. DPO is associated with a lower rate of SL, less severe SL and a later onset of SL. Revision surgery is less likely in DPO. In FFP, we recommend DPO instead of SPO for fixation of fractures of the anterior pelvic ring, which are located in or near to the pubic symphysis.


2009 ◽  
Vol 18 (9) ◽  
pp. 1335-1341 ◽  
Author(s):  
Klaus Röhl ◽  
Bernhard Ullrich ◽  
Gerd Huber ◽  
Michael M. Morlock

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Gunther Sandmann ◽  
Atesch Ateschrang ◽  
Thomas Freude ◽  
Ulrich Stöckle ◽  
Werner Schmölz ◽  
...  

Abstract Purpose Angular stable implants reduced the complication rate in the treatment of humeral head fractures. But the failure rate is still high. To further reduce the risk of cut-out, cement augmentation of screws was introduced. A reason for failure of plate osteosynthesis might be the extremely high stiffness of the screw-plate interface leading to a loss of reduction and cut-out of screws. A more homogeneous distribution of the forces on all screws may avoid secondary dislocation. We hypothesize that dynamic osteosynthesis minimizes screw loosening and results in a higher load to failure than standard locking screws. Methods Twelve paired human humerus specimens were analysed. A standardized three-part fracture model with a metaphyseal defect was simulated. Within each pair of humeri, one was fixed with a Philos plate and standard locking screws (LS), whereas the other humerus was fixed with a Philos plate and dynamic locking screws (DLS). A cyclic varus-bending test or a rotation test with increasing loading force was performed until failure of the screw-bone-fixation. Results In the varus bending test, pairs failed by screw loosening in the humeral head. The LS-group reached 2901 (601–5201) load cycles until failure, while the DLS-group failed after 3731 (2001–5601) cycles. This corresponds to a median loading of 195 N for the LS-group and 235 N for the DLS-group (p = 0.028). In the rotation test the LS-group reached a median of 1101 (501–1501) load cycles until failure of fixation occurred, while the DLS-group failed after 1401 (401–2201) cycles (p = 0.225). Conclusions Plate fixation using dynamic locking screws for the treatment of proximal humerus fractures demonstrated more load cycles until failure compared to standard locking plate osteosynthesis.


2019 ◽  
Vol 37 (7) ◽  
pp. 1498-1507 ◽  
Author(s):  
Xiaoreng Feng ◽  
Guanghu Lin ◽  
Christian X. Fang ◽  
William W. Lu ◽  
Bin Chen ◽  
...  

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1953 ◽  
Author(s):  
Marcin Kozakiewicz ◽  
Rafał Zieliński ◽  
Bartłomiej Konieczny ◽  
Michał Krasowski ◽  
Jakub Okulski

Background: In the literature, no information on plates for low-neck mandibular condylar osteosynthesis can be found, despite the fact that 30 plate designs have already been published. The aim of this study was to compare any dedicated plates for possible use in low-neck condylar fracture osteosynthesis. Methods: The force required for 1-mm displacement of the fixed fracture fragments and incidents of screw loosening were recorded on polyurethane mandibles among 16 designs of titanium plates fixed by 6-mm screws in a 2.0 system. Results: Double-straight plate fixation was the mechanical gold standard (15.2 ± 3.5 N), followed by A-shape Condylar Plates (14.9 ± 2.1 N), X-shape Condylar Plates (14.2 ± 1.3 N) and Auto Repositioning Plates (11.8 ± 2.4 N). Screw loosening was uncommon, as a minimum of three screws were placed into the condylar part. Fewer screws were lost from the ramus part of the fixation if the plate was attached to the condylar part by three screws. Often, the stability of the ramus screws was lost when there were only two fixing screws in the condyle (p < 0.001). Conclusions: It is advisable to consider the mechanical advantages as one decides which plate to choose for open rigid internal fixation in low-neck condylar fractures, or to only be aware of the significant differences in mobility within the fracture line after fixation with different dedicated plates.


2020 ◽  
Vol 99 (2) ◽  
pp. 72-76

Introduction: The aim of the study was to radiologically analyse the results of expandable implant insertion in one- to two-level cervical spine somatectomy. Methods: A total of 28 patients undergoing one- to two-level somatectomy in cervical spine were postoperatively examined by CT. The following radiological parameters were studied: Cobb angle C2-7, segmental Cobb angle, implant subsidence and bone fusion. Results: The average Cobb angle of C2-7 in preoperative images was 13.7 degrees, 13.4 degrees in the early postoperative period (p=0.88), and 10.3 degrees (p=0.043) 2 years after the surgery. The average segmental Cobb angle in preoperative images was 4.4 degrees, 5.2 degrees in the early postoperative period (p=0.61), and 0.2 degrees (p=0.01) 2 years after the surgery. Significant implant subsidence was observed in 15 cases (53.6%). Grade I fusion was achieved in 6 cases (21.4%), grade II fusion in 12 cases (42.9%), and stable pseudoarthrosis (grade III) in 9 cases (32.1%). No cases of unstable pseudoarthrosis (grade IV) were detected. Conclusion: Implantation of an expandable vertebral body implant in one- to two-level cervical spine somatectomy with ventral plate fixation is a fully acceptable way to reconstruct the ventral column of the cervical spine, providing sufficient long-term stability of the cervical spine and instrumentation and an adequate cervical spine curve.


2001 ◽  
Vol 120 (5) ◽  
pp. A40-A40 ◽  
Author(s):  
S MIEHLKE ◽  
P HEYMER ◽  
T OCHSENKUEHN ◽  
E BAESTLEIN ◽  
G YARIAN ◽  
...  

1987 ◽  
Vol 20 (3) ◽  
pp. 559-572 ◽  
Author(s):  
Robert M. Kellman ◽  
Wilfried Schilli
Keyword(s):  

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