SENSITIVITY ANALYSIS OF STEM POSITION AND CEMENT THICKNESS ON PATIENT SPECIFIC COMPUTATIONAL ANALYSIS OF CEMENTED TOTAL HIP REPLACEMENT

2012 ◽  
Vol 45 ◽  
pp. S275
Author(s):  
JunFen Shi ◽  
Martin Browne ◽  
Mike Strickland ◽  
Gunnar Flivik ◽  
Mark Taylor
2019 ◽  
Vol 30 (3) ◽  
pp. 281-287
Author(s):  
Jim W Pierrepont ◽  
Ed Marel ◽  
Jonathan V Baré ◽  
Leonard R Walter ◽  
Catherine Z Stambouzou ◽  
...  

Background: Optimal implant alignment is important for total hip replacement (THR) longevity. Femoral stem anteversion is influenced by the native femoral anteversion. Knowing a patient’s femoral morphology is therefore important when planning optimal THR alignment. We investigated variation in femoral anteversion across a patient population requiring THR. Methods: Preoperatively, native femoral neck anteversion was measured from 3-dimensional CT reconstructions in 1215 patients. Results: The median femoral anteversion was 14.4° (−27.1–54.5°, IQR 7.4–20.9°). There were significant gender differences (males 12.7°, females 16.0°; p < 0.0001). Femoral anteversion in males decreased significantly with increasing age. 14% of patients had extreme anteversion (<0° or >30°). Conclusions: This is the largest series investigating native femoral anteversion in a THR population. Patient variation was large and was similar to published findings of a non-THR population. Gender and age-related differences were observed. Native femoral anteversion is patient-specific and should be considered when planning THR.


2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Þröstur Pétursson ◽  
Kyle Joseph Edmunds ◽  
Magnús Kjartan Gíslason ◽  
Benedikt Magnússon ◽  
Gígja Magnúsdóttir ◽  
...  

The variability in patient outcome and propensity for surgical complications in total hip replacement (THR) necessitates the development of a comprehensive, quantitative methodology for prescribing the optimal type of prosthetic stem: cemented or cementless. The objective of the research presented herein was to describe a novel approach to this problem as a first step towards creating a patient-specific, presurgical application for determining the optimal prosthesis procedure. Finite element analysis (FEA) and bone mineral density (BMD) calculations were performed with ten voluntary primary THR patients to estimate the status of their operative femurs before surgery. A compilation model of the press-fitting procedure was generated to define a fracture risk index (FRI) from incurred forces on the periprosthetic femoral head. Comparing these values to patient age, sex, and gender elicited a high degree of variability between patients grouped by implant procedure, reinforcing the notion that age and gender alone are poor indicators for prescribing prosthesis type. Additionally, correlating FRI and BMD measurements indicated that at least two of the ten patients may have received nonideal implants. This investigation highlights the utility of our model as a foundation for presurgical software applications to assist orthopedic surgeons with selecting THR prostheses.


1997 ◽  
Vol 26 (1) ◽  
pp. 62-66 ◽  
Author(s):  
KIRIN B. WYLIE ◽  
DAVID J. DEYOUNG ◽  
WILLIAM TODD DROST ◽  
BONNIE A. DEYOUNG

2011 ◽  
Vol 131 (7) ◽  
pp. 1013-1019 ◽  
Author(s):  
Andreas Fottner ◽  
Arnd Steinbrück ◽  
Patrick Sadoghi ◽  
Farhad Mazoochian ◽  
Volkmar Jansson

1992 ◽  
Vol 68 (04) ◽  
pp. 436-441 ◽  
Author(s):  
Nigel E Sharrock ◽  
George Go ◽  
Robert Mineo ◽  
Peter C Harpel

SummaryLower rates of deep vein thrombosis have been noted following total hip replacement under epidural anesthesia in patients receiving exogenous epinephrine throughout surgery. To determine whether this is due to enhanced fibrinolysis or to circulatory effects of epinephrine, 30 patients scheduled for primary total hip replacement under epidural anesthesia were randomly assigned to receive intravenous infusions of either low dose epinephrine or phenylephrine intraoperatively. All patients received lumbar epidural anesthesia with induced hypotension and were monitored with radial artery and pulmonary artery catheters.Patients receiving low dose epinephrine infusion had maintenance of heart rate and cardiac index whereas both heart rate and cardiac index declined significantly throughout surgery in patients receiving phenylephrine (p = 0.0001 and p = 0.0001, respectively). Tissue plasminogen activator (t-PA) activity increased significantly during surgery (p <0.0005) and declined below baseline postoperatively (p <0.005) in both groups. Low dose epinephrine was not associated with any additional augmentation of fibrinolytic activity perioperatively. There were no significant differences in changes in D-Dimer, t-PA antigen, α2-plasmin inhibitor-plasmin complexes or thrombin-antithrombin III complexes perioperatively between groups receiving low dose epinephrine or phenylephrine. The reduction in deep vein thrombosis rate with low dose epinephrine is more likely mediated by a circulatory mechanism than by augmentation of fibrinolysis.


1991 ◽  
Vol 66 (06) ◽  
pp. 652-656 ◽  
Author(s):  
Per Anders Flordal ◽  
Karl-Gösta Ljungström ◽  
Jan Svensson ◽  
Brenda Ekman ◽  
Gustaf Neander

SummaryTwelve patients undergoing total hip replacement, with regional anaesthesia and with dextran infusion for plasma expansion and thromboprophylaxis, were given the vasopressin analogue desmopressin (DDAVP) or placebo in a randomized, double-blind prospective study. In controls (n = 6) we found a prolongation of the bleeding time, low factor VIII (FVIII) and von Willebrand factor (vWF) and a decrease in antithrombin III to levels known to be at risk for venous thrombosis. Desmopressin shortened postoperative bleeding time, gave an early FVIII/vWF complex increase, prevented antithrombin III from falling to critically low values and appeared to activate the fibrinolytic system, both by tPA increase and PAI-1 decrease.Thus in the controls we found changes in both coagulation and fibrinolysis indicating a haemorrhagic diathesis as well as a risk for thromboembolism. Desmopressin induced factor changes that possibly reduce both risks.


1976 ◽  
Vol 36 (01) ◽  
pp. 157-164 ◽  
Author(s):  
P. M Mannucci ◽  
Luisa E. Citterio ◽  
N Panajotopoulos

SummaryThe effect of subcutaneous low-dose heparin on postoperative deep-vein thrombosis (D. V. T.) (diagnosed by the 125I-labelled fibrinogen test) has been investigated in a trial of 143 patients undergoing the operation of total hip replacement. Two randomized studies were carried out: in one the scanning for D.V.T. was carried out daily for 7 days post operatively and in the other for 15 days. In both, the incidence of D.V.T. was significantly lower in the heparin-treated patients (P<0.005). Bilateral D.V.T. was also prevented (P<0.05), through the extension of D.V.T. to the distal veins of the thigh was not significantly reduced. Heparin treatment was, however, followed by a higher incidence of severe postoperative bleeding (P< 0.02) and wound haematoma formation (P< 0.005), and the postoperative haemoglobin was significantly lower than in the control group (P<0.005). A higher number of transfused blood units was also needed by the heparin treated patients (P<0.001).


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