Clinical outcomes of the Burnett "snake" maneuver shunt modification for ischemic priapism.

BACKGROUND: Major ischemic priapism (IP) is defined as a persistent penile erection for >4 hours. IP may cause serious complications, especially if prompt resolution is not achieved. Therefore, selecting the most effective and usable shunt technique is crucial in IP cases that are refractory to medical therapy. AIM: To compare the effectiveness and complication risks of distal corporoglanular shunt procedures with and without the Burnett "snake" maneuver. METHODS: We conducted a retrospective study of patients who presented with IP and underwent surgical treatment at our institution between 2005 and 2021. The patients were categorized into 2 groups: group 1 (n = 26) underwent distal shunt + Burnett snake maneuver, and group 2 (n = 56) underwent distal shunt-only. Clinical history, parameters of IP, details of medical and surgical treatments, and follow-up information were evaluated. OUTCOMES: Outcomes included differences in IP resolution and recurrence, functional erections, and complications between corporoglanular shunt procedures with and without the Burnett snake maneuver. RESULTS: In group 1, 24 of 26 patients (92.3%) experienced priapism resolution with a single surgical intervention, while this outcome was observed in 30 of 56 patients (53.6%) in group 2 (P < .001). Notably, priapism recurrence was significantly lower in group 1, occurring in 1 of 24 patients (4.2%), as opposed to 8 of 30 patients (26.6%) in group 2 (P < .001). Of the patients with documented sexual function status at follow-up, functional erections (capable of penetration with or without phosphodiesterase 5 inhibitors) were noted in 6 of 14 patients (42.8%) in group 1 and 13 of 26 patients (50%) in group 2 (P = .66). CLINICAL IMPLICATIONS: This study provides valuable insights regarding technical aspects of distal shunt procedures with and without the Burnett snake maneuver for treating major IP episodes. These results can help surgeons with clinical decision making for patients who present with IP. STRENGTH AND LIMITATIONS: Limitations include the single-site retrospective design with potential selection bias, inaccuracies in medical record data, challenges in controlling confounding variables, and the lack of validated questionnaire scores for erectile function evaluation. CONCLUSION: Our study demonstrates that modifying distal shunt procedures using the Burnett snake maneuver significantly improves priapism resolution and effectively prevents further priapism episodes without introducing additional complications or erectile function loss, thereby distinguishing it from distal shunt-only procedures.

Early-onset and uncontrolled diabetes mellitus factors correlate with complications of Peyronie's disease.

BACKGROUND: Peyronie's disease (PD) is a connective tissue disorder that affects the penis and is characterized by abnormal collagen structure in the penile tunica albuginea, resulting in plaque formation and penile deformity. PD's overall prevalence is estimated at 3.2% to 8.9%, with rates as high as 20.3% among men with type 2 diabetes mellitus (DM). However, the characteristics of DM associated with PD complications remain unclear. AIM: To explore clinical associations between DM characteristics and PD complications. METHODS: We conducted a retrospective analysis of patients with DM and PD who presented at our institution between 2007 and 2022. We examined patients' clinical histories, DM- and PD-related clinical parameters, and complications. Penile deformities were assessed through physical examination, photographs, and penile Doppler ultrasound. Patients were categorized into subgroups based on age of DM onset: early (<45 years), average (45-65 years), and late (>65 years). OUTCOMES: Outcomes included effects of DM characteristics on PD development, progression, and severity. RESULTS: In total, 197 patients were included in the evaluation. Early-onset diabetes and elevated hemoglobin A1c (HbA1c) levels exhibited significant correlations with the early development of PD (ρ = 0.66, P < .001, and ρ = -0.24, P < .001, respectively). Furthermore, having DM at an early age was associated with the occurrence of penile plaque (ρ = -0.18, P = .03), and there were no significant differences in plaque dimensions (ρ = -0.29, P = .053). A rise in HbA1c levels after the initial PD diagnosis displayed positive correlations with the formation of penile plaque (ρ = 0.22, P < .006). CLINICAL IMPLICATIONS: These findings emphasize the need for comprehensive assessments and personalized treatment strategies for individuals with DM and PD. Enhanced management approaches can improve outcomes for those facing both challenges. STRENGTHS AND LIMITATIONS: Limitations include the single-site retrospective design with potential selection bias, inaccuracies in medical record data, and challenges in controlling confounding variables. CONCLUSIONS: This study highlights that early-onset diabetes and poor diabetes control, as indicated by a subsequent rise in HbA1c levels following PD diagnosis, are significantly correlated with the onset and severity of PD. Revealing the mechanisms behind these findings will help us develop better management strategies for individuals with DM and PD.

Factors affecting implant length in primary inflatable penile prosthesis placement.

OBJECTIVES: To evaluate predictors of implant length for men undergoing primary IPP placement. METHODS: A multicenter, retrospective cohort study was performed for men undergoing primary IPP placement at 16 high-volume surgical centers. Patient demographics, comorbidities, operative approach, and implanted cylinder and rear tip extender length were recorded. Associations between potential preoperative and intraoperative predictors of total device length were tested using non-parametric correlation and Kruskal-Wallis tests, followed by multiple regression. RESULTS: Of 3,951 men undergoing primary IPP placement from July 2016 - July 2021, the median implant length was 20 cm (IQR: 19 - 22). Shorter implant length was associated with increasing age in years (ß = -0.01, p=0.009), Asian ethnicity (ß = -2.34, p=0.008), history of radical prostatectomy (ß = -0.35, p=0.001), and use of an infrapubic surgical approach (ß = -1.02, p<0.001). Black or African American ethnicity was associated with the implantation of longer devices (ß = 0.35, p<0.001). No significant associations were recorded with BMI, history of intracavernosal injections, diabetes mellitus, tobacco use, radiation therapy, Peyronie's disease, priapism, or cavernosal dilation technique. CONCLUSIONS: The length of an implanted penile prosthesis was found to be associated with preoperative and intraoperative factors including history of radical prostatectomy and operative approach. The knowledge of these associations may assist in the preoperative counseling of patients receiving IPP and help create accurate postoperative expectations.

The Role of a New Hinged Total Knee Arthroplasty System for Use in a Variety of Complex Knee Scenarios: A Case Series.

Hinged knee arthroplasties are commonly used in scenarios where there are major ligament deficiencies or bone loss around the knee. They are applicable in native knees with major deformities and during revisions. They can also be used as a salvage procedure after distal femoral resection. The new modular hinged device system, namely the Triathlon Hinge Knee (THK) System (Stryker, Mahwah, New Jersey), reflects the advancements of third-generation design and enhances surgical flexibility by allowing streamlined integration with the Triathlon Total Stabilized (TS) System (Stryker, Mahwah, New Jersey) and the Global Modular Replacement System (GMRS, Stryker, Mahwah, New Jersey). Additionally, the Triathlon Revision Tibial Baseplate (Stryker, Mahwah, New Jersey) has been launched as part of THK and is compatible with the Modular Rotating Hinge (MRH , Stryker, Mahwah, New Jersey) femur, which allows the Revision Baseplate to replace the existing tibial component while leaving the existing MRH Femoral Component in place. The Triathlon Revision Tibial Baseplate enables orthopaedic surgeons to use constrained or hinged prostheses, including both distal and total femoral replacement options, without changing the Tibial Baseplate. This is because the TS, MRH, THK, and GMRS femurs are compatible with the new Triathlon Revision Tibial Baseplate. Additionally, the system can be augmented with metaphyseal cone constructs to help provide a stable foundation for reconstruction. This report explores the application of a new modular hinged device system in various scenarios, starting with (1) complex primary hinged knee arthroplasty, followed by revision hinged knee arthroplasty cases including (2) failed TKA with medial collateral ligament (MCL) dysfunction, (3) severe arthrofibrosis post-TKA, (4) revisions for prosthetic joint infection, (5) extensor mechanism deficiency, and (6) arthrofibrosis with extensor mechanism disruption, concluding with a case of (7) distal femoral arthroplasty for periprosthetic fracture post-failed TKA.

Acute nicotine vapor normalizes sensorimotor gating and reduces locomotor activity deficits in HIV-1 transgenic rats.

Rationale: Despite improved life expectancy of people with HIV (PWH), HIV-associated neurocognitive impairment (NCI) persists, alongside deficits in sensorimotor gating and neuroinflammation. PWH exhibit high smoking rates, possibly due to neuroprotective, anti-inflammatory, and cognitive-enhancing effects of nicotine, suggesting potential self-medication. Objectives: Here, we tested the effects of acute nicotine vapor exposure on translatable measures of sensorimotor gating and exploratory behavior in the HIV-1 transgenic (HIV-1Tg) rat model of HIV. Methods: Male and female HIV-1Tg and F344 control rats (n=57) were exposed to acute nicotine or vehicle vapor. Sensorimotor gating was assessed using prepulse inhibition (PPI) of the acoustic startle response, and exploratory behavior was evaluated using the behavioral pattern monitor (BPM). Results: Vehicle-treated HIV-1Tg rats exhibited PPI deficits at low prepulse intensities compared to F344 controls, as seen previously. No PPI deficits were observed in nicotine-treated HIV1-Tg rats, however. HIV-1Tg rats were hypoactive in the BPM relative to controls, whilst nicotine vapor increased activity and exploratory behavior across genotypes. Cotinine analyses confirmed comparable levels of the primary metabolite of nicotine across genotypes. Conclusions: Previous findings of PPI deficits in HIV-1Tg rats were replicated and, importantly, attenuated by acute nicotine vapor. Evidence for similar cotinine levels suggest a nicotine-specific effect in HIV-1Tg rats. HIV-1Tg rats had reduced exploratory behavior compared to controls, attenuated by acute nicotine vapor. Therefore, acute nicotine may be beneficial for remediating sensorimotor and locomotor activity deficits in PWH. Future studies should determine the long-term effects of nicotine vapor on similar HIV/NCI-relevant behaviors.

An Advanced Knee Simulator Model Can Reproducibly Be Used for Ligament Balancing Training during Total Knee Arthroplasty.

A critical and difficult aspect of total knee arthroplasty (TKA) is ligamentous balancing for which cadavers and models have played a large role in the education and training of new arthroplasty surgeons, although they both have several shortcomings including cost, scarcity, and dissimilarity to in vivo ligament properties. An advanced knee simulator (AKS) model based on computed tomography (CT) scans was developed in the setting of these challenges with cadavers and previous models. In this study, we compared the ligament balancing between AKS and human cadaveric knees to assess the validity of using the AKS for ligament balancing training during TKA. A CT scan of a TKA patient with varus deformity was used to design the AKS model with modular components, using three-dimensional printing. Three fellowship-trained arthroplasty surgeons used technology-assisted TKA procedure to plan and balance three cadaver knees and the AKS model. Medial and lateral laxity data were captured using manual varus and valgus stress assessments for cadavers and the model in an extension pose (10 degrees of flexion from terminal extension) and between 90 and 95 degrees for flexion. After preresection assessments, surgeons planned a balanced cruciate-retaining TKA. Following bony cuts and trialing, extension and flexion ligament laxity values were recorded in a similar manner. Descriptive statistics and Student's t-tests were performed to compare the cadavers and model with a p-value set at 0.05. Preresection medial/lateral laxity data for both extension and flexion were plotted and showed that the highest standard deviation (SD) for the cadavers was 0.67 mm, whereas the highest SD for the AKS was 1.25 mm. A similar plot for trialing demonstrated that the highest SD for the cadavers was 0.6 mm, whereas the highest SD for the AKS was 0.61 mm. The AKS trialing data were highly reproducible when compared with cadaveric data, demonstrating the value of the AKS model as a tool to teach ligament balancing for TKA and for future research endeavors.

Asbestos history and use.

All six fiber types called asbestos can cause all the diseases related to exposure, including lung cancer. Known to the ancients, the modern history of asbestos hazards started in the 1890s with more and more data accumulating over time. Use increased exponentially in the middle of the 20th century with major use coming in construction and ship building. The recognition of asbestos as causing lung cancer dates to the early 1940s.

Novel application of two- and four-lobed noise-canceling passive integrated transponder antennas for tracking fish in areas of high ambient electromagnetic interference.

Passive integrated transponder (PIT) technology is a leading tool for tracking fish in freshwater systems. PIT is highly applicable for assessing fish passage at anthropogenic infrastructure (e.g., dams and floodgates); however, there are often complications in operating PIT antennas near these structures due to the ambient electromagnetic interference of metal and power-supply equipment. We designed a PIT antenna that is resistant to the effects of ambient electromagnetic interference (AEMI). This design uses lobes with balanced polarity within the antenna to neutralize AEMI within the vicinity of the antenna. This novel PIT antenna provides a more effective and cost-efficient option for researchers tracking fish in environments with high AEMI.

Oxidation and Damage Mechanisms of 2nd Generation Highly Cross-Linked Polyethylene Tibial Inserts.

INTRODUCTION: After clinical introduction in 2005, sequentially annealed, highly crosslinked polyethylene (SA HXLPE) was studied for retrievals with short implantation times; however, long-term follow-ups are lacking. The objective of this study was to examine and compare the revision reasons, damage mechanisms, and oxidation indices (OI) of SA HXLPE and conventional gamma-inert sterilized (Gamma Inert) ultra-high molecular weight polyethylene tibial inserts implanted for > 5 years. METHODS: There were 74 total knee arthroplasty (TKA) tibial inserts (46 SA HXLPEs, 28 Gamma Inerts) implanted for > 5 years (mean 7 ± 2 years) retrieved as part of a multicenter retrieval program. Cruciate-retaining implants comprised 44% of the SA HXLPEs and 14% of the Gamma Inerts. Patient factors and revision reasons were collected from revision operating notes. A semi-quantitative scoring method was used to assess surface damage mechanisms. Oxidation was measured using Fourier transform infrared microscopy according to American Society for Testing and Materials (ASTM) 2102. Differences between cohorts were assessed with Mann-Whitney U-Tests. RESULTS: Loosening (Gamma Inert: 17 of 28, SA HXLPE: 15 of 46) and instability (Gamma Inert: 6 of 28, SA HXLPE: 15 of 46) were the most common revision reasons for both cohorts. The most prevalent surface damage mechanisms were burnishing, pitting, and scratching, with burnishing of the condyles being higher in Gamma Inert components (P = 0.022). Mean oxidation was higher in the SA HXLPE inserts at the articulating surface (P = 0.002) and anterior-posterior (AP) faces (P = 0.023). No difference was observed at the backside surface (P = 0.060). CONCLUSIONS: Revision reasons and surface damage mechanisms were comparable in the Gamma Inert and SA cohorts. Further studies are needed to continue to assess the in vivo damage and clinical relevance, if any, of oxidation in SA HXLPE over longer implantation times, particularly for implants implanted for more than 10 years.

Presence of Microscopic Hematuria Does Not Predict Clinically Important Intra-Abdominal Injury in Children.

OBJECTIVE: Screening for blunt intra-abdominal injury in children often includes directed laboratory evaluation that guides need for computed tomography. We sought to evaluate the use of urinalysis in identifying patients with clinically important intraabdominal injury (ci-IAI). METHODS: A retrospective chart review was performed for all patients less than 18 years who presented with blunt mechanisms at a level I trauma center between 2016 and 2019. Exclusion criteria included transfer from an outside facility, physical abuse, and death within thirty minutes of arrival. Demographics, physical exam findings, serum chemistries, urinalysis, and imaging were reviewed. Clinically important intraabdominal injury was defined as injury requiring ≥2 nights admission, blood transfusion, angiography with embolization, or therapeutic surgery. RESULTS: Two hundred forty patients were identified. One hundred sixty-five had a completed urinalysis. For all patients an abnormal chemistry panel and abnormal physical exam had a sensitivity of 88.9% and a negative predictive value of 99.3%. Nine patients had a ci-IAI. Patients with a ci-IAI were more likely to have abdominal pain, tenderness on exam, and elevated hepatic enzymes. When patients were stratified by the presence of an abnormal chemistry or physical exam with or without microscopic hematuria, urinalysis did not improve the ability to identify patients with a ci-IAI. In fact, presence of microscopic hematuria increased the rate of false positives by 12%. CONCLUSIONS: Microscopic hematuria was not a useful marker for ci-IAI and may lead to falsely assuming a more serious injury.

Racial and socioeconomic disparities in surgical care for post-prostate cancer treatment complications: A nationwide Medicare-based analysis.

Objectives: To investigate the racial and socioeconomic (income) differences in receipt of and time to surgical care for urinary incontinence (UI) and erectile dysfunction (ED) occurring post-radical prostatectomy (RP) and/or radiation therapy (RT). Materials and Methods: Utilizing the Medicare Standard Analytical Files (SAF), a retrospective cohort study was performed on data of patients diagnosed with prostate cancer (PCa) from 2015 to 2021. Patients who underwent RP and/or RT and who subsequently developed UI and/or ED were grouped into four cohorts: RP-ED, RP-UI, RT-ED and RT-UI. County-level median household income was cross-referenced with SAF county codes, classified into income quartiles, and used as a proxy for patient income status. The rate of surgical care was compared between groups using two-sample t-test and log-rank test. Cox proportional hazards modelling was used to determine covariate-adjusted impact of race on time to surgical care. Results: The rate of surgical care was 6.8, 3.61 3.07, and 1.54 per 100 person-years for the RP-UI, RT-UI, RP-ED, and RT-ED cohorts, respectively. Cox proportional 'time-to-surgical care' regression analysis revealed that Black men were statistically more likely to receive ED surgical care (RP-ED AHR:1.79, 95% CI:1.49-2.17; RT-ED AHR:1.50, 95% CI:1.11-2.01), but less likely to receive UI surgical care (RP-UI AHR:0.80, 95% CI:0.67-0.96) than White men, in all cohorts except RT-UI. Surgical care was highest among Q1 (lowest income quartile) patients in all cohorts except RT-UI. Conclusions: Surgical care for post-PCa treatment complications is low, and significantly impacted by racial and socioeconomic (income) differences. Prospective studies investigating the basis of these results would be insightful.

Proceedings of PRINCETON IV: PDE5 inhibitors and cardiac health symposium.

INTRODUCTION: Prior consensus meetings have addressed the relationship between phosphodiesterase type 5 (PDE5) inhibition and cardiac health. Given significant accumulation of new data in the past decade, a fourth consensus conference on this topic was convened in Pasadena, California, on March 10 and 11, 2023. OBJECTIVES: Our meeting aimed to update existing knowledge, assess current guidelines, and make recommendations for future research and practice in this area. METHODS: An expert panel reviewed existing research and clinical practice guidelines. RESULTS: Key findings and clinical recommendations are the following: First, erectile dysfunction (ED) is a risk marker and enhancer for cardiovascular (CV) disease. For men with ED and intermediate levels of CV risk, coronary artery calcium (CAC) computed tomography should be considered in addition to previous management algorithms. Second, sexual activity is generally safe for men with ED, although stress testing should still be considered for men with reduced exercise tolerance or ischemia. Third, the safety of PDE5 inhibitor use with concomitant medications was reviewed in depth, particularly concomitant use with nitrates or alpha-blockers. With rare exceptions, PDE5 inhibitors can be safely used in men being treated for hypertension, lower urinary tract symptoms and other common male disorders. Fourth, for men unresponsive to oral therapy or with absolute contraindications for PDE5 inhibitor administration, multiple treatment options can be selected. These were reviewed in depth with clinical recommendations. Fifth, evidence from retrospective studies points strongly toward cardioprotective effects of chronic PDE5-inhibitor use in men. Decreased rates of adverse cardiac outcomes in men taking PDE-5 inhibitors has been consistently reported from multiple studies. Sixth, recommendations were made regarding over-the-counter access and potential risks of dietary supplement adulteration. Seventh, although limited data exist in women, PDE5 inhibitors are generally safe and are being tested for use in multiple new indications. CONCLUSION: Studies support the overall cardiovascular safety of the PDE5 inhibitors. New indications and applications were reviewed in depth.

Effects of the level and source of dietary physically effective fiber on feed intake, nutrient utilization, heat energy, ruminal fermentation, and milk production by Alpine goats.

Thirty-two primiparous and 31 multiparous Alpine goats were used to determine influences of diets varying in level and source of forage on performance in early to mid-lactation for 16 wk. Diets consisted of 40%, 50%, 60%, and 70% forage (designated as 40F, 50F, 60F, and 70F, respectively) with 60F and 70F containing coarsely ground grass hay (primarily orchardgrass) and 40F and 50F containing cottonseed hulls, alfalfa pellets, and coarsely ground wheat hay. Diets contained 15.9% to 16.3% crude protein and 37.8%, 42.1%, 53.5%, and 55.4% neutral detergent fiber (NDF) with 10.0%, 15.8%, 50.1%, and 55.5% particle retention on a 19-mm sieve, and 26.1%, 29.6%, 38.3%, and 40.0% physically effective NDF (peNDF) for 40F, 50F, 60F, and 70F, respectively. Dry matter intake (2.71, 2.75, 1.96, and 1.95 kg/d) and milk yield (2.82, 2.71, 2.23, and 2.10 kg/d for 40F, 50F, 60F, and 70F, respectively) were lower (P < 0.05) for the two diets highest in forage. Digestion of organic matter was similar among diets (P > 0.05), but digestibility of NDF was greater (P < 0.05) for 60F and 70F (57.5%, 58.4%, 68.9%, and 72.2% for 40F, 50F, 60F, and 70F, respectively). Diet affected (P < 0.05) milk fat (3.16%, 3.37%, 2.93%, and 2.97%) and protein concentrations (2.62%, 2.69%, 2.58%, and 2.52% for 40F, 50F, 60F, and 70F, respectively). Milk energy yield was greater (P < 0.05) for the two diets lowest in forage (7.51, 7.45, 5.68, and 5.34 MJ/d), although yield relative to dry matter intake was not affected (P > 0.05) by diet and was lower (P < 0.05) for primiparous vs. multiparous goats (2.71 and 3.09 MJ/kg). Ruminal pH and acetate proportion were greater for 60F and 70F than for the other diets and the proportion of butyrate was lower for the two diets highest in fiber. The mean lengths of time spent ruminating, eating, standing, and lying were not affected (P > 0.05) by diet or parity, but many interactions involving diet, period, hour, and parity were significant (P < 0.05). In conclusion, lactational performance of Alpine goats in early to mid-lactation will be constrained with diets high in forage of moderate quality, peNDF content, and large particle size, which appeared related to limited feed intake.

Evaluation of a non-dispersive infrared spectrometer for quantifying organic and elemental carbon in diesel particulate matter.

Diesel particulate matter (DPM) is a common and well-known health hazard in the mining environment. The regulatory method for monitoring both the organic and elemental carbon (OC, EC) portions of DPM is a laboratory-based thermal-optical method with a typical turnaround time of one week. In order to evaluate exposure levels and take corrective action prior to overexposure, a portable real-time device capable of quantifying both OC and EC is needed. To that end, researchers from the National Institute for Occupational Safety and Health (NIOSH) designed and tested the feasibility of a device based on bandpass optical filters that target key infrared wavelengths associated with DPM and its spectroscopic baseline. The resulting device, referred to here as a non-dispersive infrared (NDIR) spectrometer could serve as the basis of a cost-effective, field-portable alternative to the laboratory thermal-optical method. The limits of quantification (LOD) indicate that the NDIR spectrometer can quantify EC, OC, and TC provided they are present at 20, 37, and 46 µg/m3 or more, respectively. In the event that the NDIR spectrometer is integrated with a sampler and filter tape the LOD is estimated to be reduced to 13, 7, and 10 µg/m3 for EC, OC, and TC, respectively. These LOD estimates assume a face velocity of 59 cm/s and a sampling time of 30 min.

Socioeconomic and Racial/Ethnic Inequalities in Infertility Prevalence, Help-Seeking, and Help Received Since 1995.

BACKGROUND: In the United States, infertility and treatment for infertility are marked by racial/ethnic and socioeconomic inequalities. Simultaneously, biomedical advances and increased public health attention toward preventing and addressing infertility have grown. It is not known, however, whether the racial/ethnic and socioeconomic inequalities observed in infertility prevalence, help-seeking, or help received have changed over time. METHODS: Using National Survey of Family Growth data (1995 through 2017-2019 cycles), this study applied multivariable logistic regression with interaction terms to investigate whether and how racial/ethnic and socioeconomic inequalities in 1) the prevalence of infertility, 2) ever seeking help to become pregnant, and 3) use of common types of medical help (advice, testing, medication for ovulation, surgery for blocked tubes, and artificial insemination) have changed over time. RESULTS: The results showed persisting, rather than narrowing or increasing, inequalities in the prevalence of infertility and help-seeking overall. The results showed persisting racial/ethnic inequalities in testing, ovulation medication use, and surgery for blocked tubes. By contrast, the results showed widening socioeconomic inequalities in testing and narrowing inequalities in the use of ovulation medications. CONCLUSIONS: There is little evidence to suggest policy interventions, biomedical advances, or increased public health awareness has narrowed inequalities in infertility prevalence, treatment seeking, or use of specific treatments.

Femoral Head Penetration Rates and Oxidation of Highly Cross-Linked Polyethylene Hip Liners Implanted More Than 10 Years.

BACKGROUND: Highly cross-linked polyethylene (HXLPE) was introduced to improve wear in total hip arthroplasty, with manufacturers implementing different thermal treatments to reduce oxidation. It is important to understand how long-term time in vivo affects the wear of these materials. The purpose of this study was to investigate the wear and oxidative performance of first-generation HXLPE hip inserts implanted for greater than 10 years and compare annealed and remelted HXLPE formulations. METHODS: There were 49 total hip arthroplasty liners retrieved during routine revision surgery as part of an institutional review board-approved implant retrieval program. Penetration rates for the liners were calculated as the difference between the thickness of the unloaded and loaded regions divided by implantation time. Oxidation indices for the rim, locking mechanism, articulating surface, and backside regions were measured using Fourier-transform infrared spectroscopy according to American Society for Testing and Materials 2102. Mann-Whitney U tests were used to determine the statistical difference between annealed and remelted components. RESULTS: The cohort had an average implantation time of 13.1 ± 2.6 years for annealed and 12.1 ± 1.7 years for remelted components. The components were revised most often for polyethylene wear, instability, and loosening. The penetration rate averaged 0.0177 ± 0.014 mm/year for annealed components and 0.015 ± 0.022 mm/year for remelted components. Penetration rates did not differ between the remelted and annealed cohorts (P = .28). Oxidation indices were found to be significantly higher in the annealed cohort for all regions of interest (P < .001). CONCLUSIONS: Oxidation was found to be higher in the annealed HXLPE; however, this does not seem to be associated with greater wear as we found the average penetration rates for the cohorts were low, and the penetration rates were similar between the annealed and remelted cohorts.