Radiostereometric Analysis of Femoral Head Penetration in Cross-Linked Polyethylene in THR Patients

Background: In the young total hip replacement (THR) population limiting polyethylene liner wear is crucial to preventing premature implant failure. Highly cross-linked ultra-high molecular weight polyethylene (HXLPE) liners were designed to improve wear resistance of polyethylene liners. Radiostereometric analysis (RSA) provides highly precise measurements of liner wear. This study utilized RSA to characterize wear of conventional versus HXLPE liners up to five years following THR. Methods: This IRB-approved, prospective, randomized, blinded study, involved 46 patients with a mean age of 58 and BMI of 30. Each patient was double randomized to receive a conventional or HXLPE liner with an uncemented titanium mesh or tantalum trabecular metal cup. Both liners were prepared from compression-molded GUR 1050 resin without calcium stearate, while HXLPE liners undergo further e-beam irradiation and annealing. At the time of surgery, 1mm tantalum RSA markers were implanted around the liner periphery, femur and periacetabular bone. RSA examinations, Harris Hip, UCLA, WOMAC, SF-36 scores were obtained pre-operatively, post-operatively, at six weeks, six months and annually through five years. Results: All patients had statistically significant improvement in Harris Hip, WOMAC and SF-36 PCS scores following THR with no difference between cohorts. On RSA examination, of titanium shells, HXLPE liners revealed significantly lower femoral head penetration at each follow up except six weeks and six months (p Conclusion: In this young THR population RSA shows significantly less femoral head penetration in the HXLPE liners compared to conventional liners. Novel RSA techniques have been developed to determine polyethylene wear in patients

Tantalum versus Titanium Acetabular Shells in Young Active THR Patients: A Radiostereometric Analysis (RSA) Study

Introduction: In the active THR (total hip replacement) population, acetabular component stability is crucial for preventing implant failure. Titanium fiber metal coating is the most common material used in cementless THR. Trabecular metal, composed of porous tantalum, is designed to improve tissue infiltration and limit migration. It is unknown if tantalum offers an advantage over titanium in the biologic fixation of porous-coated acetabular shells. Radiostereometric analysis (RSA) provides highly precise measurements of micromotion that are otherwise not detectable by routine radiographs. Methods: In this IRB approved, prospective, randomized, blinded study, 46 patients received a primary THR by a single surgeon. Each patient was randomized to receive a titanium (23) or tantalum (23) uncemented cup. Tantalum RSA markers were implanted around the polyethylene liner and into the patient’s femur and periacetabular bone. Also, patients received either a highly cross-linked (n=25) or a conventional liner (n=21). RSA examinations, Harris Hip, UCLA, WOMAC, SF-12 scores were obtained at 10 days, 6 months, and annually through 5 years. Results: The randomized groups had comparable mean age, preoperative activity, and average BMI. The tantalum shells demonstrated less median translation than the titanium shells at each time-point, but there was no statistical difference between the two shells. At 6 months median translation of tantalum and titanium was -0.01mm and 0.04mm and remained stable with median translation of -0.02mm and 0.04mm at four years. Mean UCLA, WOMAC, Harris Hip, and SF-12 PCS and MCS scores improved similarly in both groups. Conclusions: After THR, both patient cohorts had excellent clinical outcomes with statistically significant improvements in function and pain relief. Although tantalum porous-coated acetabular shells demonstrated less y-translation and y-rotation at all time points, there was no statistically significant difference in shell migration and both shells demonstrated excellent stability with minimal micromotion at four years

Radiostereometric Analysis of Tantalum vs. Titanium Acetabular Shells in Young THR Patients

Introduction: In the active total hip replacement (THR) population, maintaining acetabular component stability and limiting polyethylene wear are crucial components to preventing premature implant failure. Titanium with Co/Cr/Mo fiber metal coating is among the most common materials used in cementless THR. Trabecular metal, composed of porous tantalum, has a metallic strut design resembling trabecular bone, designed to improve tissue infiltration and limit migration. This study assesses the stability and clinical outcomes of tantalum versus titanium acetabular shells using radiostereometric analysis (RSA) technology. Methods: In this IRB approved, prospective, randomized, blinded study, 46 patients received a primary THR by a single surgeon (DCA). Each patient was randomized to receive a titanium (23) (Trilogy, Zimmer) or tantalum (23) (Modular tantalum shell, Zimmer) uncemented hemispheric cup and either a highly-crosslinked or conventional polyethylene liner. Tantalum RSA markers were implanted around the liner periphery, femur, and periacetabular bone in each patient. RSA examinations, Harris Hip, UCLA, WOMAC, SF-36 scores were obtained at 10 days, 6 months, and annually with the furthest patients evaluated through 5 years. Results: Median translation was greater at all time points for the tantalum mesh cups except for the 3-year follow-up, however due to large standard errors, there was no significant difference between the two designs (p\u3e0.05). These large standard errors were predominantly caused by two outliers, neither of which had clinical evidence of loosening at 5 years follow-up. Mean UCLA, WOMAC, Harris Hip, and SF-36 PCS and MCS scores improved similarly in both groups. Conclusions: In this young THR population, both titanium and tantalum acetabular shells demonstrated excellent stability at five years follow up. Tantalum shells demonstrated slightly greater micromotion, but there was no statistically significant difference in shell migration. Outstanding clinical outcomes with statistically significant improvements in function and pain relief were observed in both groups

Adrenergic Dysregulation and Pain With and Without Acute Beta-Blockade in Women With Fibromyalgia and Temporomandibular Disorder

In patients with fibromyalgia syndrome (FMS) and temporomandibular disorder (TMD), stress and pain may chronically enhance sympathetic activity, altering cardiovascular responses and worsening pain. This study examined cardiovascular, epinephrine (EPI), norepinephrine (NE), cortisol and clinical pain responses in 54 female patients with these disorders and 34 controls. In a subsample of 10 FMS, 10 TMD patients and 16 controls, using a counterbalanced, double-blind, cross-over design, the same responses were assessed after intravenous administration of low dose propranolol vs. placebo. Testing included baseline, postural, speech and ischemic pain stressors. FMS patients showed lesser heart rate (HR) increases to posture challenge but greater blood pressure (BP) increases to postural and speech tasks than Controls, as well as higher overall BP and greater total vascular resistance (TVR) than TMDs or Controls. TMDs showed higher overall cardiac output and lower TVR than Controls. Both FMS and TMD groups showed lower baseline NE than Controls, and TMDs showed lower overall EPI and NE levels. Group differences in HR, EPI and NE were abolished after propranolol although BP, CO and TVR differences persisted. In both FMS and TMD, number of painful body sites and ratings of total clinical pain obtained 4 times during each session were significantly lower after beta-blockade vs. placebo

Analysis of polyethylene wear in plain radiographs: The number of radiographs influences the results

Background and purpose Two-dimensional computerized radiographic techniques are frequently used to measure in vivo polyethylene (PE) wear after total hip arthroplasty (THA), and several variables in the clinical set-up may influence the amount of wear that is measured. We compared the repeatability and concurrent validity of linear PE wear on plain radiographs using the same software but a different number of radiographs

Polyethylene Oxidation in Total Hip Arthroplasty: Evolution and New Advances

Ultra-high molecular weight polyethylene (UHMWPE) remains the gold standard acetabular bearing material for hip arthroplasty. Its successful performance has shown consistent results and survivorship in total hip replacement (THR) above 85% after 15 years, with different patients, surgeons, or designs

A Mi\u27kmaq First Nation cosmology: investigating the practice of contemporary Aboriginal Traditional Medicine in dialogue with counselling – toward an Indigenous therapeutics

This paper explores from a Mi’kmaq and Aboriginal standpoint foundational knowledge in Indigenous therapeutics. Based on an eco-social-psycho-spiritual way of working, the article proposes Indigenous cultural models that open a window to a rich cultural repository of meanings associated with Indigenous cosmology, ontology and epistemology. The three layers of meaning, theory and practice within the symbolic ‘Medicine Lodge’ or ‘Place of The Dreaming’ give rise to ways of working that are deeply integrative and wholistic. These forms of Indigenous theory and practice have much to offer the counselling and complimentary health professions

Measuring Corporate Social Responsibility in tourism: Development and validation of an efficient measurement scale in the hospitality industry.

ABSTRAC: This article aims at developing an efficient measurement scale for corporate social responsibility in the tourism industry, given the contextual character that is recognized in the practice of this construct. Indicators were generated on the basis of a literature review and qualitative research. To assess the reliability and validity, first- and second-order confirmatory factor analysis were carried out. Results show a multidimensional structure of this construct—including economic, social, and environmental issues. This study contributes to the advancement of knowledge in the field of social responsibility through its practical application regarding concepts of sustainable development which have mainly been theoretical

Electric toothbrush application is a reliable and valid test for differentiating temporomandibular disorders pain patients from controls

<p>Abstract</p> <p>Background</p> <p>Current methods for identifying patients with pain hypersensitivity are sufficiently complex to limit their widespread application in clinical settings. We assessed the reliability and validity of a simple multi-modal vibrotactile stimulus, applied using an electric toothbrush, to evaluate its potential as a screening tool for central sensitization.</p> <p>Methods</p> <p>Fourteen female temporomandibular disorders (TMD) subjects with myofascial pain (RDC/TMD Ia or Ib) and arthralgia (RDC/TMD IIIa) were compared to 13 pain-free controls of matched age and gender. Vibrotactile stimulus was performed with an electric toothbrush, applied with 1 pound pressure for 30 seconds in four locations: over the lateral pole of the temporomandibular joint, masseter, temporalis, and mid-ventral surface of forearm. Pain intensity (0–10) was recorded following the stimulus at 0, 15, 30, and 60 seconds. Test-retest reliability was assessed with measurements from 8 participants, taken 2–12 hours apart. Case versus control differentiation involved comparison of area under the curve (AUC). A receiver operating characteristic (ROC) curve was used to determine cutoff AUC scores for maximum sensitivity and specificity for this multi-modal vibrotactile stimulus.</p> <p>Results</p> <p>Test-retest reliability resulted in an ICC of 0.87 for all 4 pooled sites. ROC-determined AUC cutoff scores resulted in a sensitivity of 57% and specificity of 92% for all 4 pooled sites.</p> <p>Conclusion</p> <p>The electric toothbrush stimulus had excellent test-retest reliability. Validity of the scores was demonstrated with modest sensitivity and good specificity for differentiating TMD pain patients from controls, which are acceptable properties for a screening test.</p