The impact of operative approach and intraoperative imaging on leg length discrepancy and acetabular component angle in total hip arthroplasty: a retrospective cohort study.

PURPOSE: Operative approach in total hip arthroplasty (THA) has long been a topic of debate with each approach having unique benefits and disadvantages. One purported benefit of an anterior approach to THA is that it allows for intraoperative positioning using fluoroscopy rather than manual positioning. Proper positioning allows for improved outcomes including leg length discrepancy and acetabular component angle. This study aims to examine if operative approach and use of imaging in intraoperative positioning impact LLD and cup angle post-operatively. METHODS: A total of 300 hips were enrolled in the study with 100 hips per approach (anterior with fluoroscopy, lateral, and posterior). Retrospective chart review was conducted to assess patient demographics and radiographic analysis used to determine LLD and acetabular cup angle. RESULTS: Of the three groups, those receiving anterior approach THAs were on average older than those in the posterior group. Analysis comparing the LLD and acetabular angle across the three groups showed no statistically significant difference in LLD (p=0.091); this was also reflected when comparing hips that received fluoroscopy with those that did not (p=0.91). For acetabular angle, while no difference existed when comparing hips that received imaging versus those that did not, statistically significant differences were observed when comparing the three intraoperative approaches (p<0.0001). CONCLUSIONS: Neither intraoperative approach nor the use of intraoperative imaging in THA has a statistically significant effect on LLD post-operatively. However, approach did impact the acetabular cup angle across all three distinct approaches.

Impact of the coronavirus disease 2019 pandemic on equity of access to hip and knee replacements: a population-level study.

PURPOSE: The COVID-19 pandemic had innumerable impacts on healthcare delivery. In Canada, this included limitations on inpatient capacity, which resulted in an increased focus on outpatient surgery for non-emergent cases such as joint replacements. The objective of this study was to assess whether the pandemic and the shift towards outpatient surgery had an impact on access to joint replacement for marginalized patients. METHODS: Data from Ontario's administrative healthcare databases were obtained for all patients undergoing an elective hip or knee replacement between January 1, 2018 and August 31, 2021. All surgeries performed before March 15, 2020 were classified as "pre-COVID," while all procedures performed after that date were classified as "post-COVID." The Ontario Marginalization Index domains were used to analyze proportion of marginalized patients undergoing surgery pre- and post-COVID. RESULTS: A total of 102,743 patients were included-42,812 hip replacements and 59,931 knee replacements. There was a significant shift towards outpatient surgery during the post-COVID period (1.1% of all cases pre-COVID to 13.2% post-COVID, p < 0.001). In the post-COVID cohort, there were significantly fewer patients from some marginalized groups, as well as fewer patients with certain co-morbidities, such as congestive heart failure and chronic obstructive pulmonary disease. CONCLUSION: The most important finding of this population-level database study is that, compared to before the COVID-19 pandemic, there has been a change in the profile of patients undergoing hip and knee replacements in Ontario, specifically across a range of indicators. Fewer marginalized patients are undergoing joint replacement surgery since the COVID-19 pandemic. Further monitoring of access to joint replacement surgery is required in order to ensure that surgery is provided to those who are most in need.

Licensed and Liable. Insurance, Road Regulations, and Driving After Hip and Knee Arthroplasty Surgery.

BACKGROUND: There is a reliance on surgeons to provide advice to patients regarding safe return to driving following hip or knee arthroplasty. Concerns arise that misinformation may place the surgeon in a position of potential legal implication. The purpose of this article is to inform surgeons of their role in accordance with advice from insurance companies and transport regulatory bodies. METHODS: We sought the stipulations from 5 of the top 10 insurance companies in the United States, Canada, Australia, and the United Kingdom and the transport regulatory body of each country with regards to guidelines on driving after arthroplasty surgery. RESULTS: The transport regulatory bodies of the countries evaluated do not provide explicit recommendations regarding return to driving after hip or knee arthroplasty and place the responsibility of determining fitness to drive on the treating doctor. Insurance company policies do not contain specifics pertaining to driving after surgery and in most cases defer to the treating doctor to make this decision. Guidelines are available in Canada and America with suggested timeframes on return to driving following arthroplasty surgery. CONCLUSION: Advice regarding return to driving following hip or knee arthroplasty should be individualized for each patient; ultimately the patient must feel safe to drive knowing that they have a legal responsibility to remain in control of the vehicle at all times. It is recommended that surgeons document any discussion regarding return to driving and should not feel that they are contravening any prescriptive regulation by allowing driving when appropriate.

The International Initiative to Measure Perceived Risk in Arthroplasty: The Results From a Multinational Survey.

BACKGROUND: There is an inherent moral imperative to avoid complications from arthroplasty. Doing so at ideal cost is also associated with surgeon reputation, and, increasingly in health care delivery systems that measure and competitively score outcomes, reimbursement to the surgeons and their hospitals. As a result, patients who are perceived to be in higher risk comorbidity groups, such as the obese and diabetics, as well as those challenged by socioeconomic factors may face barriers to access elective arthroplasty. METHODS: In this initiative, surveys were sent to surgeons in 8 different countries, each adapted for their own unique payment, remuneration, and punitive models. The questions in the surveys pertained to surgeons' perception of risk regarding medical and socioeconomic factors in patients indicated for total hip or knee arthroplasty. This paper primarily reports on the results from Canada, Ireland, and the United Kingdom. RESULTS: The health care systems varied between a universal/state funded health care system (Canada) to those that were almost exclusively private (India). Some health care systems have "bundled" payment with retention of fees for postoperative complications requiring readmission/reoperation and including some with public publication of outcome data (United States and the United Kingdom), whereas others had none (Canada). There were some major discrepancies across different countries regarding the perceived risk of diabetic patients, who have variable Hemoglobin A1c cut-offs, if any used. However, overall the perception of risk for age, body mass index, age, sex, socioeconomic, and social situations remained surprisingly consistent throughout the health care systems. Any limitations set were primarily driven by surgeon decision making and not external demands. CONCLUSION: Surgeons will understandably try and optimize the health status of patients who have reversible risks as shown by best available evidence. The evidence is of variable quality, and, especially for irreversible social risk factors, limited due to concerns over cost and quality outcomes that can be influenced by experience-driven perceptions of risk. The results show that perceptions of risk do have such influence on access across many health care delivery environments. The authors recommend better risk-adjustment models for medical and socioeconomic risk factors with possible stratification/exclusions regarding reimbursement adjustments and reporting to help reverse disparities of access to arthroplasty.

Risk of Total Hip Arthroplasty After Acetabular Fracture Fixation: The Importance of Age.

BACKGROUND: Geriatric patients are the most rapidly growing cohort of patients sustaining acetabular fractures (AFs). The purpose of this study was to examine the risk of a secondary total hip arthroplasty (THA) in older patients (>60 year old) with a prior AF open reduction internal fixation (ORIF) compared with younger patients (<60 year old) with an AF ORIF on a large population level. METHODS: Using administrative health care data from 1996 to 2010 inclusive of all 202 hospitals in Ontario, Canada, all adult patients with an AF ORIF and a minimum of two year follow-up were identified and included. The risk of THA was examined using a Cox proportional hazards model adjusting for patient risk factors. Secondary outcomes included surgical complications and all-cause mortality. RESULTS: A total of 1725 patients had an AF ORIF; 1452 (84.2%, mean age of 38.3 ± 12.1 years) aged <60 years ("younger") and 273 (15.8%, mean age of 69.9 ± 7.8 years) > 60 years ("older"). The mean (SD) follow-up time for all patients was 6.9 (4.2) years. In older patients, 19.4% (53 of 273) went on to receive a secondary THA with a median time to event of 3.9 years, compared with 12.9% (187 of 1452) in the younger patient cohort with a median time of 6.9 years (HR 1.7, 95% CI: 1.2-2.3). As expected, older patients had a higher 90-day mortality rate compared with younger patients (7.7% vs. 0.7%, respectively; HR 9.2, 95% CI: 4.3-19.9; P < .001). CONCLUSION: Older patients with an AF ORIF are at a significantly higher risk for a secondary THA than younger patients with an AF ORIF.

A Large-Scale Fifteen-Year Minimum Survivorship of a Cementless Triple Tapered Femoral Stem.

BACKGROUND: This study reports the long-term outcomes of a metaphyseal fit-and-fill cementless femoral component in total hip arthroplasty (THA) with a follow-up of 15-19 years. METHODS: We conducted a retrospective review of 376 consecutive THAs (345 patients), using a triple tapered stem performed between 2000 and 2003 with a view to assessing survivorship and radiological and functional outcomes. Images were assessed for initial alignment, terminal osteolysis, or subsidence, while clinical outcomes were assessed using the St Michael's Hip Score. RESULTS: Forty-five (11.9%) hips were lost to follow-up, 20 (5.31%) had died before our 15-year cutoff follow-up, and 4 (1.06%) had declined follow-up early on, leaving 307 hips (81.64%, 276 patients) available for both clinical and radiological follow-up at a minimum of 15 years (range 15-19). The mean age at the time of operation was 49.6 years (range 19-71) and the cohort included 131 (42.67%) male and 145 (47.23%) female patients. Seven stems (2.28%) were revised: 4 due to periprosthetic fractures, 2 for periprosthetic joint infection, and 1 for adverse reaction to metal debris at the trunnion. The St Michael's Hip Score improved from 14.2 (range 9-23) preoperatively to 22.3 (range 13 to 25) at the last documented follow-up (P = .000). Kaplan-Meier survivorship with stem revision for any reason as the end point was 97.70%. Worst-case scenario Kaplan-Meier survivorship, where all lost to follow-up are considered as failures, was 85.3%. No stem was revised for aseptic loosening. CONCLUSION: This triple tapered stem in THA shows excellent survivorship beyond a minimum of 15 years.

Temporal Trends and Predictors of Thirty-Day Readmissions and Emergency Department Visits Following Total Knee Arthroplasty in Ontario Between 2003 and 2016.

BACKGROUND: Total knee arthroplasty (TKA) is the second most common surgery performed in Canada. Understanding and improving quality metrics associated with such high-volume procedures is of utmost importance to maximize value within the healthcare system, which is a balance between cost and quality. Although rates and predictors of hospital readmission and emergency department (ED) visits following TKA have previously been described in privatized healthcare settings, few studies have evaluated trends in length of stay (LOS), hospital readmissions, and ED visits following TKA in a universal single-payer system. METHODS: Using data from a provincially held and validated registry, the Institute for Clinical and Evaluative Sciences, we undertook a review of all 205,152 TKAs performed in the province of Ontario, Canada, between 2003 and 2016. We determined temporal trends in utilization, LOS, readmissions, and ED visits and evaluated patient and provider predictors of hospital readmissions and ED visits using multivariate logistic regression modeling. We also grouped and described the most common reasons for readmission and ED visits based on the available International Classification of Diseases, Ninth Revision and Tenth Revision coding information. RESULTS: LOS decreased significantly over the study period (P < .0001), from a median of 5 days (10th percentile 3 days, 90th percentile 8 days) in 2003 to a median of 3 days (10th percentile 2 days, 90th percentile 4 days) in 2016. All-cause 30-day readmissions did not change significantly over the study period, but the rate of ED visits increased significantly over time. Predictors of 30-day readmission following TKA included older age, male gender, lower income quartile, not having a postoperative visit with a primary care physician (PCP), increased comorbidities, longer LOS, urgent or revision surgery, admission to a teaching hospital, and discharge to an inpatient rehabilitation facility. Variables that predicted increased odds of an ED visit included older age, male gender, lower income quartile, not having a postop visit with a PCP, increasing comorbidities, year of surgery, longer LOS, and revision surgery. Admission to a teaching hospital and discharge to an inpatient rehabilitation facility showed a trend toward increased odds of an ED visit. CONCLUSIONS: We identified a significant increase in ED visits following TKA in Ontario between 2003 and 2016, with no corresponding increase in hospital readmissions despite a significant temporal trend toward shorter LOS. Predictors of ED visits and readmissions were similar, including male gender, lower income, higher comorbidities, and lacking a PCP visit postoperatively. Increased rates of ED visits following TKA in Ontario represent a quality problem, as they are associated with increased cost to the public healthcare system without any substantial benefit. Interventions aimed at redirecting patients from the ED for minor postoperative concerns should be investigated, as this is likely to improve care by reducing costs, improving efficiency, and enhancing patient experience.

Highly Porous Titanium Acetabular Components in Primary and Revision Total Hip Arthroplasty: A Systematic Review.

BACKGROUND: A number of papers have been published reporting on the clinical performance of highly porous coated titanium acetabular cups in primary and revision total hip arthroplasty (THA). However, no systematic review of the literature has been published to date. METHODS: The US National Library of Medicine (PubMed/MEDLINE), Embase, and the Cochrane Database of Systematic Reviews were queried for publications utilizing the following keywords: "tritanium" OR "highly-porous" AND "titanium" OR "acetabular" AND "trabecular" AND "titanium". RESULTS: Overall, 16 studies were included in this review (11,366 cases; 60% females, 2-7 years mean follow-up). The overall survival rate of highly porous titanium acetabular components in primary cases was 99.3% (10,811 of 10,886 cases), whereas the rate of aseptic loosening was 0.1%. The overall survival rate of the highly porous titanium acetabular components in revision THA cases was 93.5% (449 of 480 cases), whereas the rate of aseptic loosening was 2.1%. CONCLUSION: There was moderate quality evidence to show that the use of highly porous titanium acetabular components in primary and revision THA cases is associated with satisfactory clinical outcomes in the short- and medium-term, without showing any evidence of cup migration or radiolucency. Taking into consideration that there is no evidence yet regarding the long-term survivorship of these components, we feel that further research of higher quality is required to generate more evidence-based conclusions regarding the longevity of highly porous titanium acetabular implants compared with conventional titanium counterparts.

The early- to medium-term results of a hemispherical, porous coated acetabular shell with multiple different bearing combinations are excellent with the exception of metal-on-metal.

PURPOSE: This study prospectively reports survivorship and radiographic and clinical outcomes following primary elective total hip arthroplasty (THA) using a novel single hemispherical, porous-coated acetabular cup with five different bearing combinations and a minimum of five year follow-up. METHODS: Continuing post-market release monitoring of this cup, we prospectively enrolled 108 patients (121 THA) between 2009 and 2015. We followed this cohort by examining survivorship, in addition to clinical and radiological outcomes for metal-on-metal (MoM) compared with non-MoM bearing combinations (ceramic-on-ceramic, oxinium-on-polyethylene, ceramic-on-metal, and metal-on-polyethylene). RESULTS: All 108 (121 hips) patients were followed up. Average age at time of surgery was 45.1 years (range 19 to 71 years) of which 42.1% were males. A total of seven (5.8%) cups were revised, all of which were MoM. No osteolysis was observed in any of the patients at the latest visit with a mean follow-up of 9.1 ± 1.7 years (range 4.4-10.7 years). With MoM excluded, survivorship of the cup at five  years is 97.8%. Survivorship for MoM implants was 90.0%. Validated hip scores showed significant improvements for all bearing types and no significant difference between groups at latest follow-up (p = 0.614). There was no cup migration with any bearing surface. CONCLUSION: This cup showed excellent survivorship at five year follow-up, except for patients receiving a MoM articulation. While there were concerns over the early survivorship of this cup, our cohort and joint registry data confirm excellent outcomes.

Is Oxidized Zirconium Femoral Head Superior to Other Bearing Types in Total Hip Arthroplasty? A Systematic Review and Meta-Analysis.

BACKGROUND: Oxidized zirconium (OxZi) is a relatively new type of material that combines the strength of a metal with the surface/wears properties of a ceramic. Our aim was to investigate whether OxZi femoral heads lead to lower polyethylene wear, higher survival rate, and better clinical outcomes than the other bearing types in patients treated with total hip arthroplasty (THA). METHODS: Two reviewers independently conducted a systematic search according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses using the MEDLINE/PubMed database and the Cochrane Database of Systematic Reviews. These databases were queried with the terms: a. "oxidized" AND "zirconium" AND "total" AND "hip" AND "arthroplasty"; b. "oxinium" AND "total" AND "hip" AND "arthroplasty". The primary outcome measures were the survival rate of the bearing surfaces as well as the polyethylene wear. RESULTS: The vast majority (85.7%) of the studies, which reported the mean polyethylene wear rate, showed that there was not any significant difference between OxZi and cobalt-chrome (CoCr) femoral heads (rate ratio: 0.836; 95% confidence interval: 0.362-1.928; P = .674). All studies comparing the survival rate of OxZi and CoCr femoral heads illustrated almost excellent survivorship with both implants. CONCLUSION: OxZi femoral heads did not lead to lower polyethylene wear rate or higher survival rate, when compared with CoCr femoral heads in patients treated with THA. On the basis of these results and taking into account the higher cost of these implants, we would not recommend the routine use of OxZi femoral heads in primary THAs. LEVEL OF EVIDENCE: Systematic review and meta-analysis of therapeutic studies I-III.

Patient-Reported Outcome Measures of Total Knee Arthroplasties for Post-Traumatic Arthritis versus Osteoarthritis: A Short-Term (5- to 10-year) Retrospective Matched Cohort Study.

BACKGROUND: The objective of the study was to compare the patient-reported outcome measures (PROM) of patients with post-traumatic arthritis (PTA) versus patients with osteoarthritis (OA) undergoing total knee arthroplasty (TKA) and compare the rates of revision among these two groups. METHODS: Using a prospectively held institutional registry, we retrospectively reviewed patients ≥60 years of age who underwent unilateral TKA between May 2007 and February 2012. Patients with previous or concomitant diagnosis of inflammatory arthropathy or an initial open fracture were excluded. PTA patients were matched 1:5 with OA patients undergoing TKA. Validated PROMs were recorded at baseline before index TKA and the last follow-up. Reason and time to revision surgery was reported, and survivorship was compared using Kaplan-Meier curves. RESULTS: Seventy-five PTA patients were matched to 375 OA patients. There was no difference between these groups with respect to age (67.7 ± 5.6 vs 67.8 ± 5.5 years; P = .876), body mass index (28.6 ± 5.4 vs 28.7 ± 5.3 kg/m2; P = .948), sex (65.3% vs 65.3% females; P = .999), Charlson Comorbidity Index (21.3% vs 21.3% Index 1-2, P = .999), and time to follow-up (93.0 ± 13.4 vs 88.2 ± 13.7 months; P = .999). No statistically significant difference was found in PROMs at baseline and the last follow-up (P > .05), the rate or time to revision surgery between the two groups (P-value = .635; log-rank test). CONCLUSION: Unlike previous studies, TKA for PTA does not pose lower PROMs or higher revision rates when compared to TKA for OA. These results could help provide surgeons with a frame of reference in terms of expectations for patients with PTA undergoing TKA.

Equivalent analgesic effectiveness between perineural and intravenous dexamethasone as adjuvants for peripheral nerve blockade: a systematic review and meta-analysis.

PURPOSE: Dexamethasone is commonly used as an adjuvant to local anesthetics for peripheral nerve blockade; however, uncertainty persists regarding its optimal route of administration and safety. A systematic review and meta-analysis of randomized-controlled trials (RCTs) was conducted to compare the incremental benefits of intravenous (IV) vs perineural (PN) dexamethasone when used as adjuvants for peripheral nerve blockade to improve analgesia. SOURCES: A search strategy was developed to identify eligible articles from the Cochrane and National Library of Medicine databases from inception until June 2017. The National Center for Biotechnology Information Medical Subject Headings browser thesaurus was used to identify search terms and combinations of keywords. Any clinical trial that randomly allocated adult patients (≥ 18 yr old) to receive either IV or PN dexamethasone for peripheral nerve blockade was considered for inclusion. PRINCIPAL FINDINGS: After full-text screening of potentially eligible articles, 14 RCTs were included in this review. Overall, the use of PN dexamethasone did not provide a significant incremental benefit to the duration of analgesia [ratio of means (ROM), 1.23; Hartung-Knapp-Sidik-Jonkman (HKSJ) 95% confidence interval (CI), 0.85 to 1.85; P = 0.23] or to motor block duration (ROM, 1.14; HKSJ 95% CI, 0.98 to 1.31; P = 0.07). Also, at 24-hr follow-up, there was no significant difference between the two groups regarding pain scores (standardized mean difference, 0.36; HKSJ 95% CI, -0.08 to 0.80; I2 = 75%; P = 0.09) and cumulative opioid consumption (mean difference, 5.23 mg; HKSJ 95% CI, -4.60 to 15.06; P = 0.15). Lastly, no long-term nerve-related complications were observed with the use of PN dexamethasone. CONCLUSIONS: The results of our meta-analysis suggest that PN and IV dexamethasone provide equivalent analgesic benefits and have similar safety profiles, when used as adjuvants, for peripheral nerve blockade.

11-Year Mean Follow-Up of Acetabular Impaction Grafting With a Mixture of Bone Graft and Hydroxyapatite Porous Synthetic Bone Substitute.

BACKGROUND: We report an 11-year mean follow-up of the effectiveness of bone impaction grafting with bone and hydroxyapatite (HA) for large, uncontained acetabular defects in primary and revision hip surgeries. METHODS: Over 5 years, 47 total hip arthroplasties with uncontained acetabular deficiencies were performed by augmentation using an impaction graft with 50:50 mixture of freeze-dried bone allograft and HA. Ten were primary total hip arthroplasties and 37 revision procedures. X-rays were taken postoperatively, 6 weeks, 3 months, and then annually to assess incorporation of the graft, radiolucent lines, resorption, or migration of components. Functional outcomes were assessed by annual pain and function parts of the Harris Hip Score. RESULTS: At a mean follow-up of 10 years, the survivorship was 100%. All patients were accounted for; 6 had died. The Harris Hip Score for pain improved from 9 and 17 (primaries and revisions, respectively) to 39 and 41. For function, there was an improvement from 20 and 19 to 32 (both groups). There were lucent lines in 8 cases, 3 cups had minor/stable migration, and one cup had significant migration (>15 mm). Graft incorporation had occurred in 20 hips. CONCLUSION: This is the longest survivorship of bone impaction grafting with morcellised bone and HA substitute. Although 11-year survivorship, function and pain are excellent, radiological findings of lysis in 8 and migration in 4 cases may be of concern for the immediate future and will need close monitoring. Even in these cases, revision may be easier because of restoration of bone stock.

The Ideal Total Hip Replacement Bearing Surface in the Young Patient: A Prospective Randomized Trial Comparing Alumina Ceramic-On-Ceramic With Ceramic-On-Conventional Polyethylene: 15-Year Follow-Up.

BACKGROUND: The optimum bearing surface for total hip arthroplasty remains debatable. We have previously published our outcome at 10 years and this represents the 15-year follow-up. METHODS: A total of 58 hips (in 57 patients with a mean age of 42 years) were randomized to receive either ceramic-on-ceramic (CoC) or ceramic-on-polyethylene (CoP) total hip arthroplasty. We prospectively followed for survivorship, functional outcomes (using the Harris Hip Score and the St Michael's Hip Score [SMH]), and radiological outcomes. RESULTS: At a minimum of 15 years, 3 patients had died, but not been revised. Seven were lost to follow-up. Five cases from the CoP group were revised (4 for polyethylene wear and osteolysis). Four from the CoC were revised; one each for head fracture, instability, infection, and trunnionosis. Both groups showed statistically significant improvements in Harris Hip Score scores and SMH functional scores, with no difference between the 2 bearings. For the CoP group, there was an improvement from 15.6 to 21.5 in the SMH and from 48.8 to 88.7 (P > .05); and for CoC, this improvement was 15.8 to 23.5 and 50.3 to 94.6 (P > .05), respectively. Mean wear rate of the polyethylene was 0.092 mm/y and for the CoC was 0.018 mm/y. Two patients in the CoC group had evidence of acetabular osteolysis vs 3 in the CoP. Six patients had femoral osteolysis in the CoC group and 12 in the CoP group. CONCLUSION: Survivorship and function of the 2 bearing groups remains comparable; while the polyethylene wear and osteolysis may represent issues in the future.

Does-dual mobility still offer improved stability in smaller cup sizes? A computer modelling comparison of stability with 22-mm versus 28-mm inner heads in dual-mobility versus single-bearing constructs.

PURPOSE: Dislocation remains 1 of the leading causes of revision after primary total hip arthroplasty (THA) and there is clear evidence the dual-mobility (DM) is used more frequently to minimise this. But in smaller cups, whether the use of DM with smaller 22-mm heads imparts any increased stability compared to standard bearing is unknown; especially when those smaller cups now allow for large single-bearing (SB) heads. METHODS: 3 primary cup sizes (48 mm, 50 mm, 52 mm) were chosen a priori for modelling. Head sizes trialled for the standard bearing (SB) constructs group were 28-0 mm, 32-0 mm and 36-0 mm against neutral polyethylene liners. In the modular sub-hemispheric DM constructs the inner head sizes for the DM constructs were altered where appropriate (22-0 mm vs. 28-0 mm). Cup position, stem offset, and stem size were standardised. RESULTS: Both DM constructs outperformed all SB constructs because of a statistically significant jump distance increase (p < 0.001). However, there was no difference in range of motion (ROM) or jump distances between the 22-mm and 28-mm DM inner heads.The ROM angle before impingement between the DM (with 22-mm or 28-mm heads) and SB (with different head sizes where appropriate) showed no statistically significant difference. However, DM constructs presented significantly larger jump distances than SB constructs for both provocative dislocation tests across all 3 cup sizes.Of interest, for 50-mm and 52-mm cup sizes (for which this particular DM construct design can accommodate both 22-mm and 28-mm inner heads), there were no differences in ROM or jump distance between 22-mm versus 28-mm inner heads. CONCLUSIONS: In this computer-modelling study, DM constructs are advantageous over SB constructs for improving jump distances in clinically provocative positions, but not range of motion angles. Inner head diameter of DM has no effect on stability.

Insurance Type and Withdrawal of Life-Sustaining Therapy in Critically Injured Trauma Patients.

Importance: Withdrawal of life-sustaining therapy (WLST) decisions for critically injured trauma patients are complicated and multifactorial, with potential for patients' insurance status to affect decision-making. Objectives: To determine if patient insurance type (private insurance, Medicaid, and uninsured) is associated with time to WLST in critically injured adults cared for at US trauma centers. Design, Setting, and Participants: This retrospective registry-based cohort study included reported data from level I and level II trauma centers in the US that participated in the American College of Surgeons Trauma Quality Improvement Program (TQIP) registry. Participants included adult trauma patients who were injured between January 1, 2017, and December 31, 2020, and required an intensive care unit stay. Patients were excluded if they died on arrival or in the emergency department or had a preexisting do not resuscitate directive. Analyses were performed on December 12, 2023. Exposures: Insurance type (private insurance, Medicaid, uninsured). Main Outcomes and Measures: An adjusted time-to-event analysis for association between insurance status and time to WLST was performed, with analyses accounting for clustering by hospital. Results: This study included 307 731 patients, of whom 160 809 (52.3%) had private insurance, 88 233 (28.6%) had Medicaid, and 58 689 (19.1%) were uninsured. The mean (SD) age was 40.2 (14.1) years, 232 994 (75.7%) were male, 59 551 (19.4%) were African American or Black patients, and 201 012 (65.3%) were White patients. In total, 12 962 patients (4.2%) underwent WLST during their admission. Patients who are uninsured were significantly more likely to undergo earlier WLST compared with those with private insurance (HR, 1.54; 95% CI, 1.46-1.62) and Medicaid (HR, 1.47; 95% CI, 1.39-1.55). This finding was robust to sensitivity analysis excluding patients who died within 48 hours of presentation and after accounting for nonwithdrawal death as a competing risk. Conclusions and Relevance: In this cohort study of US adult trauma patients who were critically injured, patients who were uninsured underwent earlier WLST compared with those with private or Medicaid insurance. Based on our findings, patient's ability to pay was may be associated with a shift in decision-making for WLST, suggesting the influence of socioeconomics on patient outcomes.

Local vancomycin administration in Orthopaedic Surgery - A systematic review of comparative studies.

Background: There is still controversy surrounding the routine use of vancomycin locally in primary orthopaedic surgery procedures. Therefore, the aim of this review is to assess how local vancomycin impacts the rates and microbiology of surgical site infections. Methods: A systematic electronic search of MEDLINE, EMBASE, and Web of Science was carried out for all comparative studies comparing locally applied vancomycin to control for primary orthopaedic surgery procedures published before August 14, 2022. Results: A total of 61 studies with 65,671 patients were included for analysis. Forty-six studies used vancomycin powder, 12 studies with grafts soaked in vancomycin, two studies used vancomycin irrigation, and one study administered vancomycin interosseously. There were 15 studies (of 26) in spine surgery, five (of 14) in arthroplasty, ten (of 11) in sports medicine, and two (of five) in trauma surgery that found statistically significant decreases in overall infection rates when applying local vancomycin. Only one study (in spine surgery) found significant increases in infection rates with local vancomycin application. For spine surgery, local vancomycin application had the greatest proportion of gram-negative bacteria (40.7%) isolated compared to S. aureus (42.4%) in controls. In arthroplasty and trauma surgery, there were increases in the proportions of gram-negative bacteria when vancomycin was added. There were no reported systemic adverse reactions associated with local vancomycin use in any of the studies. Conclusion: Applying local vancomycin during primary orthopaedic surgery procedures may reduce the rates of infections in multiple different orthopaedic specialties, particularly in spine surgery and sports medicine. However, careful consideration should be applied when administering local vancomycin during specific orthopaedic procedures given the heterogeneity of included studies and breadth of surgeries included in this review. Level of evidence: Level III. A systematic review of level I - III studies.

A Geometric Analysis of Polyethylene Liners Exposed to Acrylic-based Bone Cement.

Background: Acrylic-based bone cement (polymethyl methacrylate [PMMA]) is a material commonly used in orthopaedic surgeries; however, during PMMA polymerization, a highly exothermic reaction occurs. The heat released in polymerization can damage nearby materials including poorly heat-resistant cross-linked polyethylene (XLPE). Both PMMA and XLPE are used in total hip arthroplasty and could interact during femoral stem fixation. We sought to determine if the exothermic polymerization of PMMA could alter the surface characteristics of XLPE acetabular liners. Methods: Six XLPE liners were assigned to one of 4 experimental categories with varying volumes of PMMA applied in a manner that mimicked how the 2 materials would come into contact intraoperatively. Measurements were taken both pre- and post-intervention using a coordinate measuring machine for geometric and gravimetric analysis. Light microscopy was conducted postintervention to examine the surface for damage. Results: Coordinate measuring machine measurements showed minimal gross deformation in all 6 liners, but there were isolated surface deposits in 4 of 6 liners. The average maximal surface deviations, when compared to the control, for liners exposed to 1 cc of cement, 2 cc of cement, or 1 cc of cement with a femoral head implant attached were 26.6 µm, 77.2 µm, and 26.4 µm, respectively. All but one liner showed an increase in volume following intervention when compared to the control. Subtle scratches were identified using light microscopy on all 6 liners. Conclusions: XLPE shows areas of isolated surface deformation in a dose-dependent manner but with minimal gross deformation after interacting with highly exothermic PMMA.

Association of age, sex and race with prescription of anti-osteoporosis medications following low-energy hip fracture in a retrospective registry cohort.

BACKGROUND: Initiation of anti-osteoporosis medications after hip fracture lowers the risk of subsequent fragility fractures. Historical biases of targeting secondary fracture prevention towards certain groups may result in treatment disparities. We examined associations of patient age, sex and race with anti-osteoporosis medication prescription following hip fracture. METHODS: A cohort of patients with a hip fracture between 2016-2018 was assembled from the American College of Surgeons National Surgical Quality Improvement Program registry. Patients on anti-osteoporosis medications prior to admission were excluded. Multivariable logistic regression was used to determine adjusted associations between patient age, sex and race and their interactions with prescription of anti-osteoporosis medications within 30 days of surgery. RESULTS: In total, 12,249 patients with a hip fracture were identified with a median age of 82 years (IQR: 73-87), and 67% were female (n = 8,218). Thirty days postoperatively, 26% (n = 3146) of patients had been prescribed anti-osteoporosis medication. A significant interaction between age and sex with medication prescription was observed (p = 0.04). Male patients in their 50s (OR:0.75, 95%CI:0.60-0.92), 60s (OR:0.81, 95%CI:0.70-0.94) and 70s (OR:0.89, 95%CI:0.81-0.97) were less likely to be prescribed anti-osteoporosis medication compared to female patients of the same age. Patients who belonged to minority racial groups were not less likely to receive anti-osteoporosis medications than patients of white race. INTERPRETATION: Only 26% of patients were prescribed anti-osteoporosis medications following hip fracture, despite consensus guidelines urging early initiation of secondary prevention treatments. Given that prescription varied by age and sex, strategies to prevent disparities in secondary fracture prevention are warranted.