Validation of an Optical Coordinate Measuring Machine for the Measurement of Wear at the Taper Interface in Total Hip Replacement

The results of hip simulator tests on a total of 16 total hip joints, all of them 22.25 mm Charnley designs, are presented. Wear at up to 6.75 million cycles was assessed by using a coordinate measuring machine. The results gave good agreement with clinical estimates of wear rate on the same design of joint replacement from a number of sources. Good agreement was also obtained when comparison was made with the published results from more sophisticated simulators. The major source of variation in the results was found to occur in the first million cycles where creep predominates. The results of this study support the use of this type of simplified simulator for estimating wear in a total hip prosthesis. The capability to test a significant number of joints simultaneously may make this mechanism preferable to more complex machines in many cases.

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Postoperative functioning, age, obesity, and social support influence where patients go after total hip replacement

PsycEXTRA Dataset ◽

10.1037/e556262006-011 ◽

2005 ◽

Keyword(s):

Social Support ◽

Total Hip Replacement ◽

Hip Replacement ◽

Total Hip

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The Hemodynamic and Fibrinolytic Response to Low Dose Epinephrine and Phenylephrine Infusions During Total Hip Replacement Under Epidural Anesthesia

Thrombosis and Haemostasis ◽

10.1055/s-0038-1646293 ◽

1992 ◽

Vol 68 (04) ◽

pp. 436-441 ◽

Cited By ~ 23

Author(s):

Nigel E Sharrock ◽

George Go ◽

Robert Mineo ◽

Peter C Harpel

Keyword(s):

Heart Rate ◽

Deep Vein Thrombosis ◽

Cardiac Index ◽

Total Hip Replacement ◽

Epidural Anesthesia ◽

Hip Replacement ◽

Low Dose ◽

Total Hip ◽

Vein Thrombosis ◽

Deep Vein

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.

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Effects on Coagulation and Fibrinolysis of Desmopressin in Patients Undergoing Total Hip Replacement

Thrombosis and Haemostasis ◽

10.1055/s-0038-1646480 ◽

1991 ◽

Vol 66 (06) ◽

pp. 652-656 ◽

Cited By ~ 7

Author(s):

Per Anders Flordal ◽

Karl-Gösta Ljungström ◽

Jan Svensson ◽

Brenda Ekman ◽

Gustaf Neander

Keyword(s):

Total Hip Replacement ◽

Hip Replacement ◽

Bleeding Time ◽

Antithrombin Iii ◽

Postoperative Bleeding ◽

Double Blind ◽

Total Hip ◽

Von Willebrand ◽

Willebrand Factor ◽

Coagulation And Fibrinolysis

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.

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Low-Dose Heparin and Deep-Vein Thrombosis after Total Hip Replacement

Thrombosis and Haemostasis ◽

10.1055/s-0038-1648020 ◽

1976 ◽

Vol 36 (01) ◽

pp. 157-164 ◽

Cited By ~ 34

Author(s):

P. M Mannucci ◽

Luisa E. Citterio ◽

N Panajotopoulos

Keyword(s):

Deep Vein Thrombosis ◽

Total Hip Replacement ◽

Hip Replacement ◽

Low Dose ◽

Control Group ◽

Total Hip ◽

Vein Thrombosis ◽

Dose Heparin ◽

Deep Vein ◽

Low Dose Heparin

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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