Can component and patient factors account for the variance in wear rates among bilateral total hip arthroplasty patients?

The purpose of this study was to indirectly quantify the effect of patient and component factors on polyethylene wear in patients with bilateral hip arthroplasties. Assuming that both hips experience similar levels of activity, the confounding influence of activity on wear can be removed by comparing wear rates within subjects. We studied temporal wear patterns in 21 patients with bilateral hip arthroplasty with a mean follow-up of 102 months.

Fractures of the greater trochanter induced by osteolysis with the anatomic medullary locking prosthesis.

Pathologic fractures of the greater trochanter associated with trochanteric osteolysis are a late complication of total hip arthroplasty that have been described only in case reports. In this study of 208 consecutive total hip arthroplasties with mean 12.2-year radiographic follow-up, we reviewed the incidence, presentation, treatment, and outcome of such fractures.

The odyssey of porous-coated fixation.

Among all primary total hip arthroplasties (THAs) performed at our institution between 1977 and 1998, we retrospectively reviewed the outcome of 3,314 THAs performed with Anatomic Medullary Locking (AML), Prodigy, and Solution stems (all DePuy, Warsaw, IN). These hips included 460 proximally coated stems and 2,854 extensively coated stems. Survivorship rates for proximally and extensively coated stems were >95% at 15 years, using revision for any reason as an endpoint.

Distraction osteogenesis of zygomatic bone grafts in a patient with Treacher Collins syndrome: a case report.

Zygomatic aplasia in patients with Treacher Collins syndrome requires reconstruction with autogenous bone grafts. Serial bone grafting may be required if optimal malar projection is not achieved with the initial procedure. This report demonstrates the use of distraction osteogenesis in repositioning a previously bone-grafted zygoma in an adolescent patient with Treacher Collins syndrome, thus avoiding the need for repeat bone graft harvest.

Long-term results using the anatomic medullary locking hip prosthesis.

None.

Effect of acetabular modularity on polyethylene wear and osteolysis in total hip arthroplasty.

Background: Debris from polyethylene wear causes osteolysis. In this study, we examined the effect of acetabular liner modularity on polyethylene wear and osteolysis.

Methods: We compared forty-one hips (thirty-nine patients) treated with a nonmodular, porous-coated acetabular component with a matched group of forty-one hips (forty patients) treated with a modular acetabular component.

The use of intraoperative autotransfusion during cranial vault remodeling for craniosynostosis.

Intraoperative autotransfusion salvages blood shed during surgery for use in immediate resuscitation of the patient. The purpose of this study was to determine whether such autotransfusion decreases the volume of homologous blood transfused in patients undergoing primary cranial vault remodeling for craniosynostosis. The Cobe-Bret 2 autologous blood recovery system (Hemo Concepts, Union, N.

Long-term results using the anatomic medullary locking hip prosthesis.

Since the introduction of cementless total hip arthroplasty in the early 1980s, concern has shifted from component loosening toward polyethylene wear and osteolysis. The current review of 223 consecutive unselected Anatomic Medullary Locking femoral and acetabular components extends the followup on a series of patients previously reported on at 5 and 10 years. The purposes are to describe the reasons for revisions and to assess the onset and size of osteolytic lesions, with the hypothesis that osteolysis represents an important cause of loosening.

Pattern of osteolysis around two different cementless metal-backed cups: retrospective, radiographic analysis at minimum 10-year follow-up.

In this retrospective study, we analyzed the formation of osteolysis with 2 cementless cups to evaluate if surface holes in metal shells influence the radiographic pattern of osteolysis. At a minimum of 10 years' follow-up, serial radiographs of 112 hips with Arthropor cups (having multiple shell holes) and 126 hips with Anatomic Medullary Locking (AML) cups (with no holes) were reviewed. Despite differences in variables other than cup design that can affect polyethylene wear and osteolysis rates, the incidence of osteolysis between the groups was coincidentally similar (47.

Modular component exchange for treatment of recurrent dislocation of a total hip replacement in selected patients.

Background: Exchange of modular components is a treatment option for the correction of recurrent dislocation of a total hip replacement. In this study, we reviewed our experience with this technique in order to define patient selection criteria and to report the outcome of treatment.

Methods: Of 2935 hips treated with primary porous-coated total hip arthroplasty, fourteen (in fourteen patients) that met certain preoperative and intraoperative criteria were treated with modular component exchange because of recurrent hip instability.

Total hip arthroplasty using porous-coated femoral components in patients with rheumatoid arthritis.

We studied the results of total hip arthroplasty (THA) using AML porous-coated femoral components at a mean follow-up of 11 years in a non-selected, consecutive series of patients with rheumatoid arthritis. We reviewed 64 patients with 82 primary THAs using these components. There were seven men (8 hips) and 57 women (74 hips) with a mean age of 55.

Effect of isolation of periosteum and dura on the healing of rabbit calvarial inlay bone grafts.

Little is understood about the role of the recipient site in the revascularization and incorporation of autogenous inlay bone grafts in the craniofacial skeleton. Clinical experience demonstrates that secondary complex cranial vault reconstruction performed with scarred avascular dura or poor soft-tissue coverage may undergo significant resorption, thus compromising the aesthetic outcome. This study was designed to determine the effect of isolating autogenous orthotopic inlay calvarial bone grafts from the surrounding dura and/or periosteum on graft revascularization, healing, and volume maintenance in the adult rabbit.

Wear-through of a modular polyethylene liner: four case reports.

Four patients in whom the S-ROM Total Hip System Polydial polyethylene liner was used illustrate the importance of, and difficulties in, detecting polyethylene wear-through before a complete acetabular revision is necessary. The patients in these cases had full thickness polyethylene wear-through 11 or more years after total hip arthroplasties. Dorr and Livermore wear measurements from radiographs of the patients underestimated the actual wear and did not indicate wear-through.

Comparison of in vivo wear between polyethylene liners articulating with ceramic and cobalt-chrome femoral heads.

At yearly intervals we compared the radiological wear characteristics of 81 alumina ceramic femoral heads with a well-matched group of 43 cobalt-chrome femoral heads. Using a computer-assisted measurement system we assessed two-dimensional penetration of the head into the polyethylene liner. We used linear regression analysis of temporal data of the penetration of the head to calculate the true rates of polyethylene wear for both groups.

Extended slide trochanteric osteotomy for revision total hip arthroplasty.

Background: The purpose of this study was to assess the rate of union, time to union, and complications associated with the extended slide trochanteric osteotomy. We also evaluated how outcomes were influenced by the preoperative cortical-bone thickness, the preoperative cancellous-bone quality of the greater trochanter, the number of cables used to reattach the trochanteric osteotomy fragment, and the use of cortical strut augmentation.

Methods: We reviewed the results for forty-six hips in forty-five patients who underwent a revision total hip arthroplasty with an extended slide trochanteric osteotomy between December 1991 and December 1996.

Role and mechanism of PKC in ischemic preconditioning of pig skeletal muscle against infarction.

Protein kinase C (PKC) inhibitors, chelerythrine (Chel, 0.6 mg) and polymyxin B (Poly B, 1.0 mg), and PKC activators, phorbol 12-myristate 13-acetate (PMA, 0.

beta2-adrenoceptor gene polymorphisms and blood pressure variations in East Anglian Caucasians.

Objective: The amino-terminal polymorphisms, Arg16Gly and Gln27Glu, of the beta2-adrenergic receptor (beta2AR) have been shown to affect regulation of the receptor expression by an agonist in cell culture studies. The Arg16Gly polymorphism has also been recently shown to be associated with essential hypertension. We therefore evaluated whether the amino-terminal polymorphisms of beta2AR are associated with hypertension in a Caucasian population.

The hepatic inflammatory response after acetaminophen overdose: role of neutrophils.

Acetaminophen overdose induces severe liver injury and hepatic failure. There is evidence that inflammatory cells may be involved in the pathophysiology. Thus, the aim of this investigation was to characterize the neutrophilic inflammatory response after treatment of C3Heb/FeJ mice with 300 mg/kg acetaminophen.

Calcium-channel blockade can mask the diagnosis of Conn's syndrome.

A 30-year-old woman presented with hypertension and hypokalaemia, and was found to have primary aldosteronism due to a Conn's adenoma, whose removal cured the hypertension. Before surgery, the characteristic biochemical changes which enabled the diagnosis were completely masked by administration of a calcium-channel blocker, amlodipine. It is likely that widespread use of this class of drugs contributes to under-diagnosis of Conn's syndrome as a curable cause of hypertension.

Acetabular revision with use of a bilobed component inserted without cement in patients who have acetabular bone-stock deficiency.

Background: Massive deficiency of acetabular bone stock is a challenging problem in the increasing number of patients who need a revision of a failed hip arthroplasty. The bilobed cup has been presented as one alternative reconstruction technique for hips with extensive acetabular bone loss. The purpose of this study was to assess the results with use of a bilobed acetabular component inserted without cement for revision reconstruction in hips with acetabular bone deficiency in order to clarify the indications for its use and to identify the factors that influence the clinical and radiographic outcome.

Factors influencing use of digital prostheses in workers' compensation recipients.

The purposes of this study were to retrospectively identify factors associated with decreased use of digital prostheses in workers' compensation recipients 6 months after fitting and to identify characteristics of those individuals who requested and received a second set of prostheses after demonstrating consistent use of the first set. One hundred seventy-eight patients fitted with 281 digital prostheses completed a questionnaire 6 months after fitting. Forty-nine patients (28%) stated they never or occasionally used their prosthesis (low utilization) and 42 (24%) stated they used them more than 4 hours per day (high utilization).

Straightening of aberrant carotid arteries with age in velocardiofacial syndrome.

Two cases of velocardiofacial syndrome demonstrated spontaneous straightening over a 4-year period of previously deviated carotid arteries on contrast enhanced computed tomography. Based on this finding, uncomplicated traditional pharyngeal flaps were performed on both patients. It is unknown whether straightening of aberrant vessels with age is the rule or the exception in this patient population.

A common variant of the endothelial nitric oxide synthase (Glu298-->Asp) is a major risk factor for coronary artery disease in the UK.

Background: Endothelium-derived nitric oxide (NO) is synthesised from L-arginine by endothelial nitric oxide synthase (eNOS) encoded by the NOS 3 gene on chromosome 7. Because reduced NO synthesis has been implicated in the development of coronary atherosclerosis, which has a heritable component, we hypothesised that polymorphisms of NOS 3 might be associated with increased susceptibility to this disorder.

Methods And Results: Single-strand conformation polymorphism analysis of NOS 3 identified a G-->T polymorphism in exon 7 of the gene which encodes a Glu-->Asp amino acid substitution at residue 298 of eNOS.