First report of outcomes from the patient-reported outcome measures program in the Metabolic and Bariatric Surgery Accreditation Quality Improvement Program.

BACKGROUND: Health-related quality-of-life (HRQoL) is one of the most important outcomes to metabolic and bariatric surgery (MBS) patients but was not measured by the Metabolic and Bariatric Surgery Accreditation Quality Improvement Program (MBSAQIP). A patient-reported outcome measures (PROMs) program pilot started in 2016 with MBSAQIP implementation in 2019. OBJECTIVES: To measure how MBS impacts patient HRQoL 1 and 2 years after primary laparoscopic Roux-en-Y gastric bypass (bypass) or laparoscopic sleeve gastrectomy (sleeve). SETTING: The 82 centers in the United States participating in the MBSAQIP PROMs program. METHODS: Preoperative HRQoL scores and satisfaction were compared with postoperative scores 1 and 2 years after surgery with univariate comparisons and adjusted regression models. RESULTS: There were 13,901 PROMs responses from 11,146 patients. Patient satisfaction with their MBS decision was 97%. On average, patients had significant improvement in Obesity-related Problem (OP) scores (65.8 preoperatively, 23.0 at 1 yr, and 26.3 at 2 yr; P <.05), Obesity and Weight-Loss Quality-of-Life (OWLQOL) scores (36.7 preoperatively, 77.2 at 1 yr, and 74.6 at 2 yr; P < .05), their physical health (39.2 preoperatively versus 51.7 at 1 yr and 50.0 at 2 yr), and mental health (45.6 preoperatively versus 53.3 at 1 yr and 51.4 at 2 yr). Compared with bypass patients, sleeve patients had significantly lower odds of having low OP scores postoperatively (odds ratio [95% CI) ] .67 [.53, .83]) and lower odds of high OWLQOL (.61 [.48, .77]) at 1 year. CONCLUSION: All patients regardless of procedure on average report significant improvement in their scores for OP, OWLQOL, and physical and mental health after MBS. At 1 and 2 years, bypass patients reported greater improvement in their obesity-related PROMs than sleeve patients.

Selection of patient-reported outcomes measures for implementation in the Metabolic and Bariatric Surgery Accreditation Quality Improvement Program.

BACKGROUND: The Metabolic and Bariatric Surgery Accreditation Quality Improvement Program (MBSAQIP) assesses safety after metabolic and bariatric surgery and the impact on weight and obesity-related diseases. However, changes in quality of life are likely what matters most to patients, and these are not currently assessed. The best way to measure health-related quality of life (HRQoL) is to use validated patient-reported outcomes measures (PROMs), which capture patients' perspectives of their quality of life both before and after surgery. OBJECTIVES: Identify the outcomes most important to bariatric surgery patients and identify the most appropriate validated PROMs to implement in a national program for the MBSAQIP. SETTING: Five hospitals from a single healthcare system in New England. METHODS: A series of 18 focus groups and/or interviews conducted with patients, patients' family members, and bariatric health providers determined the outcomes most important to bariatric patients and which validated PROMs would accurately measure those outcomes. Immersion crystallization was used to analyze focus group data and identify appropriate PROMs. RESULTS: Focus group participants ranked health as the most important outcome for metabolic and bariatric surgery. Self-confidence, mobility, and everyday activities were the next highest ranked HRQoL domains. The Patient-Reported Outcomes Measurement Information System 10-Item Global Health Survey was selected as the general health measure. The Obesity-Related Problems scale and the Obesity and Weight-Loss Quality of Life Instrument were the disease-specific measures selected for inclusion in the MBSAQIP PROMs program. CONCLUSION: The addition of PROMs to the MBSAQIP provides a unique opportunity to monitor HRQoL at the national level, which can foster improved shared decision-making before surgery.

Evaluating agreement between clinic- and patient-reported outcomes for weight and co-morbidities at 1 year after bariatric surgery.

BACKGROUND: Development of patient-reported outcomes (PROs) to include traditionally clinic-reported data has the potential to decrease the data-collection burden for patients and clinicians and increase follow-up rates. However, replacing clinic report by patient report requires that the data reasonably agree. OBJECTIVE: To assess agreement between PROs and clinical registry data at 1 year after bariatric surgery. SETTING: Not-for-profit organization, bariatric surgery data registry, PROs platform. METHODS: Patient- and clinic-reported 1-year postoperative weight and co-morbidities were compared for matched PROs and registry records. The co-morbidities evaluated were diabetes, sleep apnea, hypertension, gastroesophageal reflux disease, and hyperlipidemia. Weight difference in pounds and nominal groupings (binary, 4-level) for co-morbidities were assessed for agreement between data sources using descriptive statistics, Bland-Altman plots, multiple regression, and kappa coefficients. Sensitivity analyses and follow-up by response method were examined. RESULTS: Among 1130 patients with both 1-year PROs and registry weights, 95% of patient-reported weights were within 13 lb of the registry-recorded weight, and patients underreported their weight by ∼2 lb, on average. Percent agreement and kappa coefficients were highest for diabetes (n = 999; binary: 94%, κ = .72; 4-level: 86%, κ = .71) and lowest for gastroesophageal reflux disease (n = 1032; binary: 75%, κ = .40; 4-level: 57%, κ = .35). Of patients eligible for both PROs and registry 1-year follow-up, 21% had PROs only. CONCLUSIONS: One-year patient- and clinic-reported weights and disease status for patients with diabetes and hypertension showed high agreement. The degree of bias from patient report was low. Patient report is a viable alternative to clinic report for certain objective measurements and may increase follow-up.

Standardized outcome measures for pregnancy and childbirth, an ICHOM proposal.

BACKGROUND: Value-based health care aims to optimize the balance of patient outcomes and health care costs. To improve value in perinatal care using this strategy, standard outcomes must first be defined. The objective of this work was to define a minimum, internationally appropriate set of outcome measures for evaluating and improving perinatal care with a focus on outcomes that matter to women and their families. METHODS: An interdisciplinary and international Working Group was assembled. Existing literature and current measurement initiatives were reviewed. Serial guided discussions and validation surveys provided consumer input. A series of nine teleconferences, incorporating a modified Delphi process, were held to reach consensus on the proposed Standard Set. RESULTS: The Working Group selected 24 outcome measures to evaluate care during pregnancy and up to 6 months postpartum. These include clinical outcomes such as maternal and neonatal mortality and morbidity, stillbirth, preterm birth, birth injury and patient-reported outcome measures (PROMs) that assess health-related quality of life (HRQoL), mental health, mother-infant bonding, confidence and success with breastfeeding, incontinence, and satisfaction with care and birth experience. To support analysis of these outcome measures, pertinent baseline characteristics and risk factor metrics were also defined. CONCLUSIONS: We propose a set of outcome measures for evaluating the care that women and infants receive during pregnancy and the postpartum period. While validation and refinement via pilot implementation projects are needed, we view this as an important initial step towards value-based improvements in care.

Radiographic and Clinical Outcomes of Porous Titanium-Coated and Plasma-Sprayed Acetabular Shells: A Five-Year Prospective Multicenter Study.

BACKGROUND: New materials in cementless total hip arthroplasty are continuously introduced into clinical practice. The objective of this study was to compare the radiographic and clinical performances of acetabular shells made with porous titanium coating (PTC) and plasma-sprayed titanium (PS). METHODS: Data from a prospective multicenter study monitoring PTC and PS shells were analyzed. Three hundred and eighty patients (191 with PTC and 189 with PS) with postoperative (within 10 months after the operation) and 5-year radiographs were available for assessment of radiographic outcomes and patient-reported outcome measures (PROMs). A radiolucent distance between the cup and acetabulum of ≥0.5 mm was defined as a gap if it was found on a postoperative radiograph and as a radiolucency if it was found on a later follow-up radiograph for the first time. RESULTS: Postoperative gaps were more common with the PS shell (40% versus 24%, p < 0.001). However, a higher percentage of the gaps in the PTC group persisted at 5 years (56% versus 4%, p < 0.001). At 5 years, 23% of the PTC shells had a radiolucency versus 5% of the PS shells (p < 0.001). Logistic regression revealed a 5.2-fold increase in the odds for radiolucency with the PTC shell (p < 0.001). No patient underwent revision surgery due to acetabular component loosening within the study period. A PTC shell was the only factor associated with the risk of pain in a logistic regression model (odds ratio = 2.0, p = 0.035). CONCLUSIONS: PTC shells were associated with more patient-reported pain and a higher risk of radiolucency and a persistent gap at 5 years compared with the PS shells, although these outcomes were not related to each other. The clinical relevance of the radiographic findings is unclear as no prostheses were revised because of loosening, but the findings warrant additional follow-up studies. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Is the use of antidepressants associated with patient-reported outcomes following total hip replacement surgery?

Background and purpose - Patients with anxiety and/or depression tend to report less pain reduction and less satisfaction with surgical treatment. We hypothesized that the use of antidepressants would be correlated to patient-reported outcomes (PROs) 1 year after total hip replacement (THR), where increased dosage or discontinuation would be associated with worse outcomes. Patients and methods - THR cases with pre- and postoperative patient-reported outcome measures (PROMs) were selected from the Swedish Hip Arthroplasty Register (n = 9,092; women: n = 5,106). The PROMs were EQ-5D, visual analog scale (VAS) for pain, Charnley class, and VAS for satisfaction after surgery. These cases were merged with a national database of prescription purchases to determine the prevalence of antidepressant purchases. Regression analyses were performed where PROs were dependent variables and sex, age, Charnley class, preoperative pain, preoperative health-related quality of life (HRQoL), patient-reported anxiety/depression, and antidepressant use were independent variables. Results - Antidepressants were used by 10% of the cases (n = 943). Patients using antidepressants had poorer HRQoL and higher levels of pain before and after surgery and they experienced less satisfaction. Preoperative antidepressant use was independently associated with PROs 1 year after THR regardless of patient-reported anxiety/depression. Interpretation - Antidepressant usage before surgery was associated with reduced PROs after THR. Cases at risk of poorer outcomes may be identified through review of the patient's medical record. Clinicians are encouraged to screen for antidepressant use preoperatively, because their use may be associated with PROs after THR.

Thirteen-Year Evaluation of Highly Cross-Linked Polyethylene Articulating With Either 28-mm or 36-mm Femoral Heads Using Radiostereometric Analysis and Computerized Tomography.

BACKGROUND: The objective of this 13-year prospective evaluation of highly cross-linked ultra high molecular weight polyethylene (HXLPE) was to (1) assess the long-term wear of HXLPE articulating with 2 femoral head sizes using radiostereometric analysis (RSA) and to (2) determine if osteolysis is a concern with this material through the use of plain radiographs and computerized tomography (CT). METHODS: All patients received a Longevity HXLPE liner with tantalum beads and either a 28-mm or 36-mm femoral head. Twelve patients (6 in each head size group) agreed to return for 13-year RSA, plain radiograph, and CT follow-up. The 1-year and 13-year plain radiographs as well as the CT scans were analyzed for the presence of osteolysis. RESULTS: The 13-year mean ± standard error steady-state wear was 0.05 ± 0.02 mm with no significant increase over time or between the 2 head size groups. Two patients' CT scans showed radiolucent regions in the acetabulum of 4.51 cm(3) and 11.25 cm(3), respectively. In one patient, this area corresponded to a partially healed degenerative cyst treated with autograft during surgery. The second patient had an acetabular protrusio treated with autograft, and the CT scan revealed areas of remodeling of this graft. One patient's 13-year plain radiographs showed evidence of cup loosening and linear radiolucencies in zones 2 and 3. CONCLUSION: There was no evidence of significant wear over time using RSA. The CT scans did not show evidence of osteolysis due to wear particles. These results suggest that this material has reduced wear compared to conventional polyethylene, irrespective of head size.

Stable Fixation of a Cementless, Proximally Coated, Double Wedged, Double Tapered Femoral Stem in Total Hip Arthroplasty: A 5-Year Radiostereometric Analysis.

BACKGROUND: The objective of this 5-year prospective study of 51 hips was to assess migration of a cementless tapered femoral stem using radiostereometric analysis (RSA), plain radiographs (radiolucencies), and patient-reported outcome measures (PROMs). METHODS: Forty-seven patients (51 hips) agreed to participate in this prospective RSA study. All patients received a Taperloc stem. Tantalum beads were inserted into the femoral bone surrounding the stem to measure migration using RSA. RSA films, plain radiograph, and PROM follow-up were obtained immediately after surgery, 6 months, 1, 2, 3, and 5 years after surgery. RESULTS: The median (interquartile range) subsidence was 0.03 mm (-0.23 to 0.06) at 5 years, with no significant differences over time. Four outlier stems had >1.5 mm of subsidence by 1 year. No stem showed radiolucencies in more than 3 zones during the 5 years. All PROMs remained favorable at 5 years, suggesting an excellent outcome. There were no stems revised for mechanical loosening; 1 stem was revised for an infection. CONCLUSION: After initial settling, the cementless tapered femoral stems in our series were stable. The 4 outlier stems with >1.5 mm of subsidence by 1 year remain stable at 5 years. RSA was the most sensitive method of detection for stems at greater risk for potential future failure. This report adds contributions to the positive results associated with this type of fixation. The results at 5 years showed excellent midterm survivorship in this cohort with a cementless tapered femoral component.

Five-Year Experience of Vitamin E-Diffused Highly Cross-Linked Polyethylene Wear in Total Hip Arthroplasty Assessed by Radiostereometric Analysis.

BACKGROUND: Vitamin E-diffused highly cross-linked polyethylene (VEPE) was developed to reduce oxidation without compromising mechanical strength. The purpose of this study was to evaluate VEPE in vivo using radiostereometric analysis (RSA) and patient-reported outcome measures (PROMs). METHODS: Fifty-one hips were enrolled. Each patient received a VEPE liner, a porous titanium shell, and an uncemented stem with a 32-mm cobalt-chrome femoral head. Tantalum beads were inserted into the VEPE to measure femoral head penetration using RSA. RSA radiographs and PROMs were obtained preoperatively immediately after surgery, 6 months, 1, 2, 3, and 5 years after surgery. RESULTS: Forty-seven hips returned at 3 years, and 42 hip at 5 years. The mean ± standard error of the mean proximal head penetration into the polyethylene was 0.06 ± 0.01 at 5 years. The amount of head penetration did not change significantly with increasing time in vivo. The mean ± standard error of the mean Harris Hip Score was 58 ± 2 preoperatively, which improved significantly to 93 ± 2 at 5 years (P < .001). CONCLUSION: The head penetration into VEPE liners was low compared with non-VEPE at 5 years. After settling of the liners in the early period, no significant head penetration occurred from 2- to 5-year follow-up. All PROMs improved significantly from preoperative to postoperative and remained very favorable at 5 years. This study documents the longest-term evaluation of in vivo wear performance of VEPE.

Analysis of Dual Mobility Liner Rim Damage Using Retrieved Components and Cadaver Models.

BACKGROUND: The objective of this study was to assess the retentive rim of retrieved dual mobility liners for visible evidence of deformation from femoral neck contact and to use cadaver models to determine if anterior soft tissue impingement could contribute to such deformation. METHODS: Fifteen surgically retrieved polyethylene liners were assessed for evidence of rim deformation. The average time in vivo was 31.4 months, and all patients were revised for reasons other than intraprosthetic dislocation. Liner interaction with the iliopsoas was studied visually and with fluoroscopy in cadaver specimens using a dual mobility system different than the retrieval study. For fluoroscopic visualization, a metal wire was sutured to the iliopsoas and wires were also embedded into grooves on the outer surface of the liner and the inner head. RESULTS: All retrievals showed evidence of femoral neck contact. The cadaver experiments showed that liner motion was impeded by impingement with the iliopsoas tendon in low flexion angles. When observing the hip during maximum hyperextension, 0°, 15°, and 30° of flexion, there was noticeable tenting of the iliopsoas caused by impingement with the liner. CONCLUSION: Liner rim deformation resulting from contact with the femoral neck likely begins during early in vivo function. The presence of deformation is indicative of a mechanism inhibiting mobility of the liner. The cadaver studies showed that liner motion could be impeded because of its impingement with the iliopsoas. Such soft tissue impingement may be one mechanism by which liner motion is routinely inhibited, which can result in load transfer from the neck to the rim.

3-year follow-up of a long-term registry-based multicentre study on vitamin E diffused polyethylene in total hip replacement.

PURPOSE: Preclinical studies of vitamin E diffused highly cross-linked polyethylene (E-XLPE) has shown enhanced mechanical properties with less wear. The purpose of our study was to document the early clinical outcome of E-XLPE to ensure, for the safety of patients, that there are no unforeseen early adverse events from using this new biomaterial. METHODS: The enrolled patients (n = 977) have received either a porous titanium coated or porous plasma sprayed acetabular shell with either a E-XLPE liner or a medium cross-linked (AXL) liner. At each follow-up 5 patient-reported outcome measures (PROMs) were completed: Harris Hip Score, Case Mix Indicator, UCLA Activity Score, SF-36, and EQ-5D. Radiographs were measured for cup and stem position, as well as femoral head penetration into the liner (wear). Postoperative complications and revisions were collected. RESULTS: At 3 years follow-up, there were 13 revisions due to: 4 periprosthetic fractures; 1 sepsis; 6 instabilities; and 2 implant mismatches at surgery. Wear of the hip implant, calculated by software analysis of pelvis x-rays, from the postoperative interval to 3 years showed a liner penetration rate of 0.027 mm/year for AXL and 0.005 mm/year for E-XLPE with no significant difference between the 2 (p = 0.24). Improvement was seen in all PROMs from the preoperative interval to 3 years after surgery (p<0.0001). CONCLUSIONS: Early follow-up of the E-XLPE and AXL liners show low penetration. PROMs indicate improvement after total hip arthroplasty in functionality and quality of life across the centers. We have not observed any early in vivo adverse effects from diffusing the liners with vitamin E. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT00545285.

Acetabular Dysplasia and Surgical Approaches Other Than Direct Anterior Increases Risk for Malpositioning of the Acetabular Component in Total Hip Arthroplasty.

BACKGROUND: Persistent acetabular dysplasia (AD) after periacetabular osteotomy has been hypothesized to increase the risk for malpositioning of the acetabular component. In this study, we investigate whether AD is an independent risk factor for cup malpositioning during primary total hip arthroplasty (THA). METHODS: Patient demographics, surgical approach, presence of AD assessed using the lateral center-edge angle, and acetabular cup positioning determined using Martell Hip Analysis Suite were investigated in 836 primary THA patients enrolled in a prospective multicenter study. RESULTS: We found that presence of AD, defined as the lateral center-edge angle of <25°, is an independent risk factor for malpositioning of the acetabular component during primary THA. Surgical approach other than direct anterior was also independently associated with malpositioned cups. CONCLUSIONS: Surgeons should therefore take special care during placement of the acetabular component in patients with AD.

Radiostereometric and Radiographic Analysis of Glenoid Component Motion After Total Shoulder Arthroplasty.

Aseptic glenoid component loosening is a common cause of total shoulder arthroplasty (TSA) failure, but early detection is difficult because pain often appears late and radiolucent lines are of uncertain significance. This study sought to answer the following questions: (1) What types of glenoid component motion may be observed during the first 3 years following implantation?; (2) Is the appearance of radiolucent lines around the glenoid component a reliable indicator of component motion?; and (3) Are clinical outcomes correlated with early glenoid component motion within the first 3 years after TSA? Eleven patients (mean age, 60.6 years) underwent TSA using a cemented, all-polyethylene glenoid component with tantalum bead implantation. Clinical outcomes (American Shoulder and Elbow Surgeons [ASES] score, visual analog scale [VAS] pain score, and range of motion) were compared pre- and postoperatively, and radiolucencies were graded according to the criteria of Lazarus et al. Patients were evaluated using radiostereometric analysis at 6 months and 1, 2, and 3 years postoperatively to measure component micromotion in translation and rotation. At a mean follow-up of 50.2 months, mean ASES score had improved from 30.3 to 81.3 (P<.001), mean VAS pain score had improved from 8 to 1 (P<.001), active forward flexion had improved from 109° to 155° (P=.001), active external rotation had improved from 28° to 54° (P=.003), and internal rotation had improved from the level of the sacrum to L3 (P=.002). Radiolucencies were detected around none of the components at 1 year, 6 components at 2 years, and 5 components at 3 years, and these radiolucencies were mostly found around components that experienced high levels of rotational motion.

A Novel Method for Assessment of Polyethylene Liner Wear in Radiopaque Tantalum Acetabular Cups: Clinical Validation in Patients Enrolled in a Randomized Controlled Trial.

Conventional radiostereometric analysis (RSA) for wear is not possible in patients with tantalum cups. We propose a novel method for wear analysis in tantalum cups. Wear was assessed by gold standard RSA and the novel method in total hip arthroplasty patients enrolled in a randomized controlled trial receiving either titanium or tantalum cups (n=46). The novel method estimated the center of the head using a model based on identification of two proximal markers on the stem and knowledge of the stem/head configuration. The novel method was able to demonstrate a pattern of wear that was similar to the gold standard in titanium cups. The novel method offered accurate assessment and is a viable solution for assessment of wear in studies with tantalum cups.

New cementless fixation in hip arthroplasty: a radiostereometric analysis.

INTRODUCTION: Scyon Orthopaedics AG developed a new mode of cementless fixation of the femoral component that provides immediate and permanent anchorage by monocortical locking screws. The aim of this study was to evaluate the stability of the Scyon total hip replacement (THR) stem in-vivo. METHODS: A total of 15 patients, with an average age of 50 years had surgery between 2008 and 2011. Each patient received a Scyon THR. Standard questionnaires were completed at each follow-up visit for evaluation of functional outcomes. RSA, patient reported outcomes, and plain radiographic follow-up were obtained at 6 months, 1 year, 2 years, and 5 years postoperatively. RESULTS: The median ± standard error (SE) stem subsidence (negative y-translation) was 0.07 ± 0.07 mm at 1 year, 0.05 ± 0.04 mm at 2 years and 0.04 ± 0.13 mm at 5 years. The median ± SE stem rotation (y-rotation) was 0.1 ± 0.21 degrees at 1 year, 0.51 ± 0.31 degrees at 2 years and 0.60 ± 0.37 degrees at 5 years. Plain radiographs showed bone on-growth onto medial aspect of the stem. Median HHS improved from 55 preoperatively to 93 at 1 year and 97 at 5 years. The median UCLA Activity Score improved from 4 preoperatively to 6 at 1 year and 5 years. CONCLUSIONS: RSA results indicate that the Scyon stem with its 5 monocortical locking screws is stable at 5 years. Immediate surgical fixation of the stem and bony on-growth onto the femoral component may ultimately decrease the rate of aseptic stem loosening in these THR patients.

Precision of radiostereometric analysis (RSA) of acetabular cup stability and polyethylene wear improved by adding tantalum beads to the liner.

BACKGROUND AND PURPOSE: In traditional radiostereometric analysis (RSA), 1 segment defines both the acetabular shell and the polyethylene liner. However, inserting beads into the polyethylene liner permits employment of the shell and liner as 2 separate segments, enabling distinct analysis of the precision of 3 measurement methods in determining femoral head penetration and shell migration. PATIENTS AND METHODS: The UmRSA program was used to analyze the double examinations of 51 hips to determine if there was a difference in using the shell-only segment, the liner-only segment, or the shell + liner segment to measure wear and acetabular cup stability. The standard deviation multiplied by the critical value (from a t distribution) established the precision of each method. RESULTS: Due to the imprecision of the automated edge detection, the shell-only method was least desirable. The shell + liner and liner-only methods had a precision of 0.115 mm and 0.086 mm, respectively, when measuring head penetration. For shell migration, the shell + liner had a precision of 0.108 mm, which was better than the precision of the shell-only method. In both the penetration and migration analyses, the shell + liner condition number was statistically significantly lower and the bead count was significantly higher than for the other methods. INTERPRETATION: Insertion of beads in the polyethylene improves the precision of femoral head penetration and shell migration measurements. A greater dispersion and number of beads when combining the liner with the shell generated more reliable results in both analyses, by engaging a larger portion of the radiograph.

Radiostereometric analysis study of tantalum compared with titanium acetabular cups and highly cross-linked compared with conventional liners in young patients undergoing total hip replacement.

BACKGROUND: Radiostereometric analysis provides highly precise measurements of component micromotion relative to the bone that is otherwise undetectable by routine radiographs. This study compared, at a minimum of five years following surgery, the micromotion of tantalum and titanium acetabular cups and femoral head penetration in highly cross-linked polyethylene liners and conventional (ultra-high molecular weight polyethylene) liners in active patients who had undergone total hip replacement. METHODS: This institutional review board-approved prospective, randomized, blinded study involved forty-six patients. Patients were randomized into one of four cohorts according to both acetabular cup and polyethylene liner. Patients received either a cementless cup with a titanium mesh surface or a tantalum trabecular surface and either a highly cross-linked polyethylene liner or an ultra-high molecular weight polyethylene liner. Radiostereometric analysis examinations and Short Form-36 Physical Component Summary, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), University of California Los Angeles (UCLA) activity, and Harris hip scores were obtained preoperatively, postoperatively, at six months, and annually thereafter. RESULTS: All patients had significant improvement (p < 0.05) in Short Form-36 Physical Component Summary, WOMAC, UCLA activity, and Harris hip scores postoperatively. On radiostereometric analysis examination, highly cross-linked polyethylene liners showed significantly less median femoral head penetration at five years (p < 0.05). Steady-state wear rates from one year to five years were 0.04 mm per year for ultra-high molecular weight polyethylene liners and 0.004 mm per year for highly cross-linked polyethylene liners. At the five-year follow-up, the median migration (and standard error) was 0.05 ± 0.20 mm proximally for titanium cups and 0.21 ± 0.05 mm for tantalum cups. CONCLUSIONS: In this young population who had undergone total hip replacement, radiostereometric analysis showed significantly less femoral head penetration in the highly cross-linked polyethylene liners compared with that in the conventional ultra-high molecular weight polyethylene liners. Penetration rates were one order of magnitude less in highly cross-linked polyethylene liners compared with ultra-high molecular weight polyethylene liners. There was no significant difference in proximal migration between the tantalum and titanium acetabular cups through the five-year follow-up (p > 0.19).

Effects of Obesity on Health Related Quality of Life Following Total Hip Arthroplasty.

Obesity is known to negatively impact health related quality of life (HRQoL). Although non-disease specific tools have been used to study HRQoL after THA in obese patients, these do not directly measure health utility improvements. All 435 THA patients in the current study, regardless of BMI, reported improvement in HRQoL as measured by EQ-5D, a universal, standardized, non-disease specific preference-based instrument. These data suggest obese patients value their quality of life improvement following THA as much as non-obese patients. Furthermore, the increased activity level observed following THA in obese patients suggests obese patients may also obtain non-disease specific benefits of a more active lifestyle. This information is important for future assessments of value and cost-effectiveness of THA in the obese population.

Three Year RSA Evaluation of Vitamin E Diffused Highly Cross-linked Polyethylene Liners and Cup Stability.

Vitamin E diffusion into highly cross-linked polyethylene (E-XLPE) is a method for enhancing oxidative stability of acetabular liners. The purpose of this study was to evaluate in vivo penetration of E-XLPE using radiostereometric analysis (RSA). Eighty-four hips were recruited into a prospective 10-year RSA. This is the first evaluation of the multicenter cohort after 3-years. All patients received E-XLPE liners (E1, Biomet) and porous-titanium coated cups (Regenerex, Biomet). There was no difference (P=0.450) in median femoral head penetration into the E-XLPE liners at 3-years comparing cobalt-chrome heads (-0.028mm; inter-quartile range (IQR) - 0.065 to 0.047) with ceramic heads (-0.043mm, IQR - 0.143to0.042). The 3-year follow-up indicates minimal E-XLPE liner penetration regardless of head material and minimal early cup movement.