Biomechanical evaluation of triple pelvic osteotomy with and without additional ventral plate stabilization

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.


1998 ◽  
Vol 11 (02) ◽  
pp. 85-93 ◽  
Author(s):  
Joanne R. Cockshutt ◽  
H. Dobson ◽  
C. W. Miller ◽  
D. L. Holmberg ◽  
Connie L. Taves ◽  
...  

SummaryA retrospective case series study was done to determine the long-term outcome of operations upon dogs treated for canine hip dysplasia by means of a triple pelvic osteotomy (TPO). Twentyfour dogs with bilateral hip dysplasia, that received a unilateral TPO between January 1988 and June 1995, were re-examined at the Ontario Veterinary College. The assessment included physical, orthopedic and lameness examinations, standard blood work, pelvic radiographs and force plate gait analysis. They were compared to bilaterally dysplastic dogs that had not been treated, and also to normal dogs. Force plate data analysis demonstrated a significant increase in peak vertical force (PVF) and mean vertical force over stance (MVF) in the limb that underwent surgical correction by means of a TPO, when compared to the unoperated hip. It was determined that performing a unilateral TPO on a young dysplastic dog resulted in greater forces and weight bearing being projected through the TPO corrected limb when compared to the unoperated limb.Dogs with bilateral hip dysplasia treated with a unilateral triple pelvic osteotomy (TPO) were assessed by force plate gait analysis, radiographs and orthopedic examination. There was a significant increase in hip Norberg angles over time, although degenerative changes did progress. Limbs that had been operated upon had significantly greater peak and mean ground reaction forces than limbs that had not received an operation.


1993 ◽  
Vol 06 (04) ◽  
pp. 202-207 ◽  
Author(s):  
Cindy Fries ◽  
Audrey Remedios

SummaryIn 12 dogs with hip dysplasia, 20 triple pelvic osteotomies (eight bilateral and four unilateral) were performed. Screw loosening, occurring in six of 12 dogs (seven of 20 osteotomies), was the most common complication after surgery. Implants loosened from the cranial ilium in six hemipelvises (30%) and from both fragments in one hemipelvis, two to six weeks (mean — three) after the operation. Medial acetabular displace-ment caused pelvic narrowing (6 to 9%, mean = 8%) in three of four dogs. Medial ischial displacement decreased pelvic diameter (11 to 21%, mean = 17%) in four of seven osteotomies. All of the dogs with implant failure were treated conservatively with cage rest and in two cases Ehmer slings were used. Although none were lame, gait abnormalities were evident in three of seven dogs on follow-up examinations four to 12 months (mean = six) later.Screw loosening, occurring in seven of 20 hemipelvises, was the most common postoperative complication associated with triple pelvic osteotomy. Fixation failures were managed conservatively. Despite decreased pelvic diameter in four of seven animals, none were lame or showed signs of pelvic obstruction at follow-up examinations four to 12 months later.


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.


2020 ◽  
pp. 112070002096700
Author(s):  
Suleman Qurashi ◽  
Matthew H Pelletier ◽  
Tian Wang ◽  
Nicholas Bramich ◽  
Jason Chinnappa ◽  
...  

Background: The aim of this study was to investigate total hip arthroplasty (THA) Morse taper pull-off strengths after impaction prior to cyclical loading compared to cyclical loading alone. The practical relevance of the experiment is to provide a perspective on what may be clinically satisfactory taper assembly given the spectrum of head tapping patterns used by surgeons, as well as compare traditional impaction performed in standard THA with alternate methods of taper engagement such as ‘ in situ assembly’ used in micro-invasive techniques. Methods: 36 taper constructs utilising a combination of cobalt-chrome alloy and ceramic-titanium alloy junctions were investigated in vitro in wet and dry conditions with cyclical loading of the constructs. Taper disengagement strengths with and without impaction were compared. Secondary investigation of the surface roughness of the heads and tapers was also assessed. Results: An impaction to a wet taper resulted in a greater pull off force compared to a dry taper with a CoCr head and taper combination. Impacting the head and dryness of the taper did not affect pull off forces of a ceramic femoral head on titanium taper. Pulling a head off a taper significantly alters the head surface roughness. Conclusion: Impaction of a taper does not provide any benefit over cyclical loading of a taper assembly alone for pull-off strength.


2019 ◽  
Vol 124 ◽  
pp. e503-e509
Author(s):  
Chunxiang Xiong ◽  
Juli Luo ◽  
Dong Yin ◽  
Xinli Zhan ◽  
Huijiang Liu

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.


2007 ◽  
Vol 7 (5) ◽  
pp. 542-548 ◽  
Author(s):  
Lisa A. Ferrara ◽  
Illya Gordon ◽  
Madeline Coquillette ◽  
Ryan Milks ◽  
Aaron J. Fleischman ◽  
...  

Object A preliminary in vitro biomechanical study was conducted to determine if the pressure at a bone graft–mortise interface and the load transmitted along a ventral cervical plate could be used as parameters to assess fusion status. Methods An interbody bone graft and a ventral plate were placed at the C3–4 motion segment in six fresh cadaveric goat spines. Polymethylmethacrylate (PMMA) was used to simulate early bone fusion at the bone graft site. The loads along the plate and the simultaneous pressures induced at the graft–endplate interfaces were monitored during simulated stages of bone healing. Each specimen was nondestructively tested in compression loading while the pressures and loads at the graft site were recorded continuously. Each specimen was tested under five conditions (Disc, Graft, Plate, PMMA, and Removal). Results The pressure at the interface of the bone graft and vertebral endplate did not change significantly with the addition of the ventral plate. The interface pressure and segmental stiffness did increase following PMMA augmentation of the bone graft (simulating an intermediate phase of bone fusion). The load transmitted along the ventral plate in compression increased after the addition of the bone graft, but decreased after PMMA augmentation. Thus, there was an increase in pressure at the graft–endplate interface and a decrease in load transferred along the ventral plate after the simulation of bone fusion. Upon removal of the ventral plate, the simulated fusion bore most of the axial load, thus explaining a further increase in graft site pressure. Conclusions These observations support the notions of load sharing and the redistribution of loads occurring during and after bone graft incorporation. In the clinical setting, these parameters may be useful in the assessment of fusion after spine surgery. Although feasibility has been demonstrated in this preliminary study, further research is needed.


2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Li-Ren Chang ◽  
Chien-Chung Chen ◽  
Seng Feng Jeng ◽  
Yu-Ray Chen ◽  
Lain-Chyr Hwang ◽  
...  

Purpose. To evaluate the biomechanical properties of the modified novel 2-hole monocortical plate fixation (2HMCPf) and traditional 4-hole monocortical plate fixation (4HMCPf) techniques in bilateral sagittal splitting osteotomy (BSSO) synthesis using a finite element analysis (FEA) and an in vitro biomechanical test with the application of a shearing loading force on a sawbone mandible model. Materials and Methods. A three-dimensional mandible models were generated using the geometry obtained from the computerized tomography image of a sawbone mandible. Plates and screws were generated and combined with the mandible in a CAD environment. The 2HMCPf and traditional 4HMCPf techniques for BSSO osteosynthesis were then analyzed under the occlusal load using the FEA. An in vitro biomechanical test was executed to verify the result of FEA. The force on fixation failure and pattern of failure were recorded. Results. The results revealed that the von Mises Stress on the mandible cortical bone (75.98 MPa) and the screw/plate (457.19 MPa) of the 2HMCPf group was lower than that of the 4HMCPf group (987.68 MPa, 1781.59 MPa). The stress concentrated on the central region of the 4HMCPf group and the distal set of the 2HMCPf group. In vitro study using the sawbone mandible model showed mechanical failure at the region of the proximal segment near the osteotomy site with the 4HMCPf group (average 32.198 N) but no failure on the fixation sites with the 2HMCPf group. Instead, the mandible sawbone fractured on the condyle neck region (average 44.953 N). Conclusion. From the biomechanical perspective, we proved that the 2HMCPf method was able to withstand a higher shearing loading force than the 4HMCPf fixation method in BSSO osteosynthesis.


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