Characterization of neurological morbidity associated with thyroid antibodies: Hashimoto's encephalopathy and beyond.

BACKGROUND: Hashimoto's Encephalopathy (HE) manifests with various neurologic symptoms associated with elevated thyroglobulin (TG) and/or thyroperoxidase (TPO) antibodies. Some patients with thyroid antibodies exhibit neurological presentations not consistent with HE. This study aims to characterize the spectrum of neurological morbidity in patients with thyroid antibodies. METHODS: We reviewed all patients tested for TG or TPO antibodies from 2010 to 2019. Patients tested for thyroid antibodies as part of a neurological workup for new symptoms were classified into the following categories: patients meeting full criteria for HE, patients with other neuroimmunological disorders, patients with unexplained neurological symptoms not fully meeting HE criteria, and patients with incidental non neuroimmunological disorders. RESULTS: There were 2717 patients with positive thyroid antibodies in the dataset including 227 patients (78% female, age 54 ± 19 years) who met inclusion criteria. Twelve patients (5%) met HE criteria, 30 (13%) had other neuroimmunological disorders, 32 (14%) had unexplained neurological symptoms, and 153 (67.4%) had incidental disorders. In addition to cognitive dysfunction, seizures, movement disorders, motor weakness, and psychosis, HE patients were also more likely to have cerebellar dysfunction, language impairment, and sensory deficits. They were more likely to carry a Hashimoto's thyroiditis diagnosis and had higher titers of thyroid antibodies. They all had a robust response to steroids. CONCLUSION: The neurological spectrum of HE may be wider than previously reported, including frequent cerebellar, sensory, and language dysfunction. A subgroup of thyroid antibody positive patients with unexplained neurological symptoms may represent further expansion of thyroid antibody-related neurological disorders.

To Stage or Not to Stage? Comparison of Patient-Reported Outcomes, Complications, and Discharge Disposition After Staged and Simultaneous Bilateral Posterior Total Hip Arthroplasty.

BACKGROUND: Patients who have bilateral hip arthritis can be treated with bilateral total hip arthroplasty (bTHA) in either a staged or simultaneous fashion. The goal of this study was to determine whether staged and simultaneous posterior bTHA patients differ in regard to (1) patient-reported outcome measures, (2) 90-day complication rates, and (3) discharge dispositions and cumulative lengths of stay. METHODS: Patients who (1) underwent simultaneous bTHA or staged bTHA (within 12 months) using the posterior approach, and (2) completed preoperative and 1-year postoperative Hip dysfunction and Osteoarthritis Outcome Score for Joint Replacement surveys were included in the study. A total of 266 patients (87 simultaneous bTHA and 179 staged bTHA) were included. Chart review was performed to collect patient-level variables, postoperative complications, discharge dispositions, and lengths of stay. RESULTS: Staged bTHA patients had higher Hip dysfunction and Osteoarthritis Outcome Score for Joint Replacement, Lower Extremity Activity Scale, and Veterans RAND 12-Item Health Survey physical component scores compared to simultaneous bTHA patients at 6 weeks after surgery (P = .019, .006, and .008, respectively), but these differences did not meet the minimal clinically important difference threshold for any questionnaire. Simultaneous bTHA was associated with higher rate of periprosthetic fractures (P = .034) and discharge to a location other than home (P < .001). CONCLUSIONS: There were statistically significant, but likely not clinically meaningful differences in patient-reported outcomes for staged and simultaneous bTHA patients at 6 weeks after surgery. Surgeons should be aware of the higher periprosthetic fracture risk and greater likelihood of discharge to a rehabilitation facility associated with simultaneous bTHA. Further research should aim to understand which patients may benefit most from simultaneous bTHA.

Survivorship and Clinical Outcomes of Primary Total Knee Arthroplasty Performed in Patients 35 Years of Age and Younger.

BACKGROUND: Total knee arthroplasties (TKAs) for patients aged ≤35 years are rare but necessary for patients who have diseases such as juvenile idiopathic arthritis, osteonecrosis, osteoarthritis, and rheumatoid arthritis. Few studies have examined the 10-year and 20-year survivorship and clinical outcomes of TKAs for young patients. METHODS: A retrospective registry review identified 185 TKAs in 119 patients aged ≤ 35 years performed between 1985 and 2010 at a single institution. The primary outcome was implant survivorship free of revision. Patient-reported outcomes were assessed at 2 time points: 2011 to 2012 and 2018 to 2019. The average age was 26 years (range, 12 to 35). Mean follow-up was 17 years (range, 8 to 33). RESULTS: Survivorship decreased from 84% (95% confidence interval [CI]: 79 to 90) at 5 years to 70% (95% CI: 64 to 77) at 10 years and to 37% (95% CI: 29 to 45) at 20 years. The most common reasons for revision were aseptic loosening (6%) and infection (4%). Risk factors for revision included increasing age at time of surgery (Hazards Ratio [HR] 1.3, P = .01) and use of constrained (HR 1.7, P = .05) or hinged prostheses (HR 4.3, P = .02). There were 86% of patients reporting that their surgery resulted in "a great improvement" or better. CONCLUSION: Survivorship of TKAs in young patients is less favorable than expected. However, for the patients who responded to our surveys, TKA demonstrated substantial pain relief and improvement in function at 17-year follow-up. Revision risk increased with older age and higher levels of constraint.

Hemostatic Agents in Orthopedic Surgery.

Controlling blood loss is a crucial aspect of orthopedic surgery. Hemostatic agents can be used intraoperatively in combination with antifibrinolytics as part of an overall strategy to limit blood loss. Several new hemostatic agents have recently come to the market designed specifically for vascular surgery but have found uses in other surgical fields, including orthopedics. This article reviews the mechanisms of action and best uses of various mechanical hemostats, active hemostats, flowable hemostats, and fibrin sealants for achieving hemostasis in orthopedic surgery. Mechanical and active hemostats have been reported to successfully decrease blood loss from cancellous bone, capillaries, and venules. Flowable hemostats are generally favorable for use in small spaces where the swelling capabilities of mechanical and active hemostats can be detrimental to surrounding structures. Sealants are best used for closing defects in tissues.

Spine or Hip First? Outcomes in Patients Undergoing Sequential Lumbar Spine or Hip Surgery.

BACKGROUND: Lumbar spine pathology frequently coexists in patients who have hip arthrosis. There is controversy on whether lumbar or hip pathology should be first addressed. The purpose of this study was to evaluate the outcomes of sequential lumbar spine (LSP) or hip arthroplasty (THA). METHODS: Using a large national database from 2010 to 2020, we reviewed the records of 241,279 patients who had concurrent hip arthritis and lumbar spine disease defined as spinal stenosis, lumbar radiculopathy, or degenerative disc disease. During the study period, 6,458 (2.7%) patients with concurrent hip/spine disease underwent sequential operative treatment of either the hip joint or lumbar spine within 2 years. The rates of subsequent surgery in either the hip or the spine, opioid requirements, and rates of hip dislocation were determined and analyzed using compared Chi-squared analyses. RESULTS: Patients undergoing THA first had lower risk of subsequent spinal procedure compared to patients who had spinal procedures first (5.7 versus 23.7%, P < .001). This disparity was maintained up to 5 years (P < .001). Opioid requirements at 1 year were highest in patients who underwent spinal procedures only (836 pills/patient) compared to any other group THA only (566 pills/patient), LSP and then THA (564 pills/patient), THA and LSP (586 pills/patient). Also, THA following LSP was associated with significantly higher rates of dislocation compared to patients undergoing THA first (3.2 versus 1.9%, P < .001). CONCLUSION: Total hip arthroplasty first in patients who have concurrent spine disease was associated with lower risk of subsequent surgery, opioid requirement, and risk of postoperative instability compared to patients having lumbar procedure first.

Outcomes After Revision Total Knee Arthroplasty From a Specific, Now-Recalled Implant System.

BACKGROUND: A specific total knee arthroplasty (TKA) implant system was recently recalled for high incidence of early polymeric wear and osteolysis. We analyzed the early outcomes of aseptic revision with these implants. METHODS: We identified 202 aseptic revision TKAs of this implant system performed at a single institution between 2010 and 2020. Revision indications included aseptic loosening (n = 120), instability (n = 55), and polymeric wear/osteolysis (n = 27). Components were revised in 145 cases (72%) and isolated polyethylene insert exchange occurred in 57 cases (28%). Kaplan-Meier and Cox proportional hazards analyses were used to determine survivorship free from all-cause rerevision and rerevision risk factors. RESULTS: At 2 and 5 years, survivorship free from all-cause rerevision was 89 and 76% in the polyethylene exchange cohort versus 92 and 84% in the component revision cohort (P = .5). At 2 and 5 years, survivorship in revision with components from the same manufacturer was 89 and 80% compared to 95 and 86% in revision with components from a different manufacturer (P = .2). Among re-revisions (n = 30), cones (37%), sleeves (7%), hinge/distal femoral replacement implants were frequently used (13%). Men had increased risk for rerevision (hazard ratio = 2.3, P = .04). CONCLUSION: In this series of aseptic revision TKAs performed on a now-recalled implant system, survivorship free from rerevision was lower than expected when components from the same manufacturer were utilized, but comparable to contemporary reports when both the components were revised with an alternative implant system. Metaphyseal fixation with cones and sleeves as well as highly constrained implants was frequently utilized at time of rerevision TKA. LEVEL OF EVIDENCE: Level IV.

Mid-term survivorship of primary total knee arthroplasty with a specific implant.

The purpose of this study was to assess mid-term survivorship following primary total knee arthroplasty (TKA) with Optetrak Logic components and identify the most common revision indications at a single institution. We identified a retrospective cohort of 7,941 Optetrak primary TKAs performed from January 2010 to December 2018. We reviewed the intraoperative findings of 369 TKAs that required revision TKA from January 2010 to December 2021 and the details of the revision implants used. Kaplan-Meier analysis was used to determine survivorship. Cox regression analysis was used to examine the impact of patient variables and year of implantation on survival time. The estimated survivorship free of all-cause revision was 98% (95% confidence interval (CI) 97% to 98%), 95% (95% CI 95% to 96%), and 86% (95% CI 83% to 88%) at two, five, and ten years, respectively. In 209/369 revisions there was a consistent constellation of findings with varying severity that included polyethylene wear and associated synovitis, osteolysis, and component loosening. This failure mode, which we refer to as aseptic mechanical failure, was the most common revision indication. The mean time from primary TKA to revision for aseptic mechanical failure was five years (5 months to 11 years). In this series of nearly 8,000 primary TKAs performed with a specific implant, we identified a lower-than-expected mid-term survivorship and a high number of revisions with a unique presentation. This study, along with the recent recall of the implant, confirms the need for frequent monitoring of patients with Optetrak TKAs given the incidence of polyethylene failure, osteolysis, and component loosening.

Tumors Constitute a Majority of Total Knee Arthroplasty in Patients <21 Years Old: A United States Nationwide Analysis.

BACKGROUND: Total knee arthroplasty (TKA) is rarely performed in patients under 21 years old, but the frequency of utilization of TKA in this population in the United States is not known. The purpose of this study was to evaluate trends in the use of TKA in patients <21 in the United States. Additionally, we aimed to determine the characteristics of these patients and the hospitals in which this procedure is performed. METHODS: We retrospectively reviewed the Kids' Inpatient Database, a national weighted sample of all inpatient hospital admissions in the United States in patients <21 years of age. We used International Classification of Diseases, Ninth Revision (ICD-9) and ICD-10 codes to identify patients undergoing TKA from 2000 to 2019 and determine a primary diagnosis. Descriptive statistics were calculated using the appropriate sample weights. RESULTS: The total weighted number of TKAs performed in patients <21 years from 2000 to 2019 was 1,535. There were 70.9% of TKAs performed for a primary diagnosis of tumor, and the use of TKA for malignant tumors has increased. In contrast, the use of TKA for inflammatory arthritis/juvenile idiopathic arthritis decreased significantly over the study period. The majority of TKAs were performed in urban teaching hospitals with a large bed size. CONCLUSION: Approximately 1,535 TKAs have been performed in patients <21 years from 2000 to 2019 in the United States. The majority of these procedures were performed for reconstruction after resection of a malignant tumor. The rate of TKA for inflammatory arthritis/juvenile idiopathic arthritis has decreased over the past two decades.

Factors Associated With Increasing Length of Stay for Rheumatoid Arthritis Patients Undergoing Total Hip Arthroplasty and Total Knee Arthroplasty.

Background: Total hip arthroplasty (THA) and total knee arthroplasty (TKA) are cost-effective procedures that decrease pain and improve health-related quality of life for patients with advanced symptomatic arthritis, including rheumatoid arthritis (RA). Patients with RA have a longer length of stay (LOS) after THA or TKA than patients with osteoarthritis, yet the factors contributing to LOS have not been investigated. Purpose: We sought to identify the factors contributing to LOS for patients with RA undergoing THA and TKA at a single tertiary care orthopedic specialty hospital. Methods: We retrospectively reviewed data from a prospectively collected cohort of 252 RA patients undergoing either THA or TKA. Demographics, RA characteristics, medications, serologies, and disease activity were collected preoperatively. Linear regression was performed to explore the relationship between LOS (log-transformed) and possible predictors. A multivariate model was constructed through backward selection using significant predictors from a univariate analysis. Results: Of the 252 patients with RA, 83% were women; they had a median disease duration of 14 years and moderate disease activity at the time of arthroplasty. We had LOS data on 240 (95%) of the cases. The mean LOS was 3.4 ± 1.5 days. The multivariate analysis revealed a longer LOS for RA patients who underwent TKA versus THA, were women versus men, required a blood transfusion, and took preoperative opioids. Conclusion: Our retrospective study found that increased postoperative LOS in RA patients undergoing THA or TKA was associated with factors both non-modifiable (type of surgery, sex) and modifiable (postoperative blood transfusion, preoperative opioid use). These findings suggest that preoperative optimization of the patient with RA might focus on improving anemia and reducing opioid use in efforts to shorten LOS. More rigorous study is warranted.

Decreased Implant Survival is Associated With Younger Patients Undergoing Total Knee Arthroplasty.

Background: Younger patients are undergoing total knee arthroplasty (TKA) at increasing rates and may face multiple revisions during their lifetimes due to mechanical complications or infections. Questions/Purposes: We sought to compare the early complication rates and revision-free implant-survival rates across age groups of patients undergoing TKA, with particular focus on implant survival in younger patients. Methods: We conducted a retrospective analysis of data taken from a national insurance database on patients who underwent primary TKA from 2007 to 2015. Kaplan-Meier curve survival analysis and log rank test were performed to evaluate revision rates in 7 age groups (younger than 40, 40-49, 50-59, 60-69, 70-79, 80-89, and 90 or more years of age). Complication rates were compared to rates in the age 60 to 79 years age groups using multiple logistic regression, controlling for baseline demographics and comorbidities. Results: There were 114,698 patients included in the analysis. Patients in the younger than 40 years, 40 to 49 years, and 50 to 59 years age groups had increased rates of early mechanical complications; 90-day readmission rates were significantly higher in those age groups as well. Revision-free implant survival at 5 years was significantly worse in patients younger than 60 years of age, particularly those less than 40 years, who had a 77% revision-free implant-survival rate at 5 years. Conclusions: Younger patients had a higher risk of early revision after TKA, as well as an increased rate of mechanical complications and readmissions at 90 days. These outcomes suggest more study is needed to better understand these discrepancies and to better guide preoperative counseling for young patients considering TKA.

Satisfaction With the Process vs Outcome of Care in Total Hip and Knee Arthroplasty.

BACKGROUND: Patient satisfaction, with both process of care and outcome of care, is critical for measuring the quality and value of elective procedures such as arthroplasty. The purpose of this study is to evaluate the correlation between early postoperative satisfaction with the process of care and 2-year satisfaction with the outcome of care after total hip arthroplasty (THA) and total knee arthroplasty (TKA). METHODS: We retrospectively analyzed data from institutional arthroplasty registries. Satisfaction with the outcome of care was measured on a scale of 0-100 by a previously validated questionnaire administered 2 years postoperatively. Patient satisfaction with the process of care was measured by the Press Ganey (PG) inpatient survey, also scored 0-100. We examined the correlation between these 2 measures of satisfaction in patients who underwent primary THA or TKA. RESULTS: In total, 721 TKA patients and 760 THA patients underwent surgery and completed both the PG survey and 2-year satisfaction questionnaire. The mean age was 65.1 years with a mean body mass index of 28.8 and 56% were female. The mean PG survey score for the entire cohort was 95.6. The mean 2-year satisfaction score was 90.3. The Spearman correlation coefficient between the PG survey and the 2-year satisfaction survey was 0.23 for TKA patients (P < .001) and 0.13 for THA patients (P < .001). CONCLUSION: We found a weak correlation between the measurement of satisfaction with the process of care surrounding hip and knee arthroplasty using the PG survey and measurement of satisfaction with the outcome of care after arthroplasty using a validated 2-year satisfaction instrument.

Primary Care Provider Density and Elective Total Joint Replacement Outcomes.

BACKGROUND: Primary care physicians (PCPs) are often gatekeepers to specialist care. This study assessed the relationship between PCP density and total knee (TKA) and total hip arthroplasty (THA) outcomes. METHODS: We obtained patient-level data from an institutional registry on patients undergoing elective primary TKA and THA for osteoarthritis, including Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain and function scores at baseline and 2 years. Using geocoding, we identified the number of PCPs in the patient's census tract (communities). We used Augmented Inverse Probability Weighting and Cross-validated Targeted Minimum Loss-Based Estimation to compare provider density and outcomes adjusting for potential confounders. RESULTS: Our sample included 3606 TKA and 4295 THA cases. The median number of PCPs in each community was similar for both procedures: TKA 2 (interquartile range 1, 6) and for THA 2 (interquartile range 1, 7). Baseline and 2-year follow-up WOMAC pain, function, and stiffness scores were not statistically significantly different comparing communities with more than median number of PCPs to those with less than median number of PCPs. In sensitivity analyses, adding 1 PCP to a community with zero PCPs would not have statistically significantly improved baseline or 2-year follow-up WOMAC pain, function, and stiffness scores. CONCLUSIONS: In this sample of patients who underwent elective TKA or THA for osteoarthritis, we found no statistically significant association between PCP density and pain, function, or stiffness outcomes at baseline or 2 years. Further studies should examine what other provider factors affect access and outcomes in THA and TKA.

Use of Total Hip Arthroplasty in Patients Under 21 Years Old: A US Population Analysis.

BACKGROUND: The purpose of this study is to evaluate trends in the use of total hip arthroplasty (THA) in the United States in patients under 21 years of age. Specifically, we examined the frequency of THA in this patient population over the past 2 decades, the epidemiologic characteristics of patients under 21 who underwent THA, and the characteristics of the hospitals where these procedures were performed. METHODS: We retrospectively reviewed the Kids' Inpatient Database, an inpatient US national weighted sample of hospital admissions in patients under 21 from approximately 4200 hospitals in 46 states. We queried the database using Current Procedural Terminology codes for elective and non-elective primary THA for the years 2000-2016. We utilized the International Classification of Diseases, Ninth Revision and International Classification of Diseases, Tenth Revision codes to determine primary diagnoses. RESULTS: The weighted total number of THAs performed in patients under 21 in the Kids' Inpatient Database increased from 347 in 2000 to 551 in 2016. The most common diagnoses were osteonecrosis, osteoarthritis, and inflammatory arthritis. The frequency of THA for osteonecrosis increased from 24% in 2000 to 38% in 2016, while the frequency of THA for inflammatory arthritis decreased from 27% in 2000 to 4% in 2016. CONCLUSION: The number of THAs in patients under 21 in the United States has increased over the past 2 decades and these procedures are increasingly performed in urban teaching hospitals. The decrease in THA for inflammatory arthritis in this population likely reflects improvements in medical management during the study period.

Sequencing of Circulating Microbial Cell-Free DNA Can Identify Pathogens in Periprosthetic Joint Infections.

BACKGROUND: Over 1 million Americans undergo joint replacement each year, and approximately 1 in 75 will incur a periprosthetic joint infection. Effective treatment necessitates pathogen identification, yet standard-of-care cultures fail to detect organisms in 10% to 20% of cases and require invasive sampling. We hypothesized that cell-free DNA (cfDNA) fragments from microorganisms in a periprosthetic joint infection can be found in the bloodstream and utilized to accurately identify pathogens via next-generation sequencing. METHODS: In this prospective observational study performed at a musculoskeletal specialty hospital in the U.S., we enrolled 53 adults with validated hip or knee periprosthetic joint infections. Participants had peripheral blood drawn immediately prior to surgical treatment. Microbial cfDNA from plasma was sequenced and aligned to a genome database with >1,000 microbial species. Intraoperative tissue and synovial fluid cultures were performed per the standard of care. The primary outcome was accuracy in organism identification with use of blood cfDNA sequencing, as measured by agreement with tissue-culture results. RESULTS: Intraoperative and preoperative joint cultures identified an organism in 46 (87%) of 53 patients. Microbial cfDNA sequencing identified the joint pathogen in 35 cases, including 4 of 7 culture-negative cases (57%). Thus, as an adjunct to cultures, cfDNA sequencing increased pathogen detection from 87% to 94%. The median time to species identification for cases with genus-only culture results was 3 days less than standard-of-care methods. Circulating cfDNA sequencing in 14 cases detected additional microorganisms not grown in cultures. At postoperative encounters, cfDNA sequencing demonstrated no detection or reduced levels of the infectious pathogen. CONCLUSIONS: Microbial cfDNA from pathogens causing local periprosthetic joint infections can be detected in peripheral blood. These circulating biomarkers can be sequenced from noninvasive venipuncture, providing a novel source for joint pathogen identification. Further development as an adjunct to tissue cultures holds promise to increase the number of cases with accurate pathogen identification and improve time-to-speciation. This test may also offer a novel method to monitor infection clearance during the treatment period. LEVEL OF EVIDENCE: Diagnostic Level II. See Instructions for Authors for a complete description of levels of evidence.

High Satisfaction and Activity Levels After Total Hip Arthroplasty in Patients Under Age 21.

BACKGROUND: With improved materials and bearing surfaces, the use of total hip arthroplasty (THA) in young patients is increasing. Functional outcomes and activity level are particularly relevant in this higher-demand patient population. There is a paucity of data on patient-reported outcomes and activity levels after THA in extremely young (<21 years old) patients. METHODS: We identified 196 patients (222 hips) who underwent THA at age <21 years at our institution from 1982 to 2018. After applying exclusion criteria, 113 of 160 (70.6%) patients (129 hips) were available for follow-up. Patient activity levels and functional outcomes were evaluated using the UCLA activity score, Forgotten Joint Score (FJS), Hip Disability and Osteoarthritis Outcome Score for Joint Replacement, and a validated 5-question satisfaction survey. Survivorship and reasons for revision were recorded. RESULTS: The mean age at surgery was 17.0 ± 2.8 years, and the mean follow-up was 13.2 years (range 2-38 years). The most common indications for THA were osteonecrosis (34%) and juvenile idiopathic arthritis (30%). The mean UCLA activity score was 5.9 ± 2.0, and 64% of patients reported a score ≥6. The mean FJS was 57.9 ± 31.0. The mean Hip Disability and Osteoarthritis Outcome Score for Joint Replacement score was 84.6 ± 16.6. Ninety percent of patients reported that they were very or somewhat satisfied with their surgery. At final follow-up, 27 of 129 (20.9%) hips had undergone revision surgery. CONCLUSION: THA performed in patients under 21 years of age with end-stage hip disease allows for high levels of activity and satisfaction postoperatively, with most patients being able to participate in moderate recreational activities. These data may be useful for surgeons in planning for and counseling extremely young patients indicated for THA.

Differences in time to return to work among patients undergoing simultaneous versus staged bilateral total knee arthroplasty.

AIMS: Many patients undergoing total knee arthroplasty (TKA) have severe osteoarthritis (OA) in both knees and may consider either simultaneous or staged bilateral TKA. The implications of simultaneous versus staged bilateral TKA for return to work are not well understood. We hypothesized that employed patients who underwent simultaneous bilateral TKA would have significantly fewer days missed from work compared with the sum of days missed from each operation for patients who underwent staged bilateral TKA. METHODS: The prospective arthroplasty registry at the Hospital for Special Surgery was used. Baseline characteristics and patient-reported outcome scores were evaluated. We used a linear regression model, adjusting for potential confounding variables including age, sex, preoperative BMI, and type of work (sedentary, moderate, high activity, or strenuous), to analyze time lost from work after simultaneous compared with staged bilateral TKA. RESULTS: We identified 152 employed patients who had undergone simultaneous bilateral TKA and 61 who had undergone staged bilateral TKA, and had completed the registry's return to work questionnaire. The simultaneous group missed a mean of 46.2 days (SD 29.1) compared with the staged group who missed a mean total of 68.0 days of work (SD 46.1) when combining both operations. This difference was statistically significant (p < 0.001). In multivariate mixed regression analysis adjusted for age, sex, BMI, American Society of Anesthesiologists status, and type of work, the simultaneous group missed a mean of 16.9 (SD 5.7) fewer days of work compared with the staged group (95% confidence interval 5.8 to 28.1; p = 0.003). CONCLUSION: Employed patients undergoing simultaneous bilateral TKA missed a mean of 17 fewer days of work as a result of their surgical treatment and rehabilitation compared with those undergoing staged bilateral TKA. This information may be useful to surgeons counselling employed patients with bilateral OA of the knee who are considering surgical treatment. Cite this article: Bone Joint J 2021;103-B(6 Supple A):108-112.

Early Recovery Outcomes in Patients Undergoing Total Hip Arthroplasty Through a Posterior Approach With Modified Postoperative Precautions.

BACKGROUND: Recent data suggest that a modified, more lenient set of precautions after total hip arthroplasty (THA) performed through the posterolateral approach may safely allow more patient movement and exercise in the immediate postoperative period. We hypothesize that 1) patients undergoing THA given modified precautions will demonstrate a fast-track return to functional activity and 2) wrist-based activity trackers will provide valuable information on postoperative activity levels. METHODS: We prospectively enrolled patients undergoing THA. Patients were given a wrist-based, commercially available activity tracker to wear 1 week preoperatively and 6 weeks postoperatively. Postoperative hip precautions included only the avoidance of the "leg-shaving" position of combined hip flexion, adduction, and internal rotation. Linear mixed models were used to analyze the change in steps and Hip Disability and Osteoarthritis Outcome Score-Junior (HOOS)-JR data. Pearson correlation coefficients were used to describe the relationship between average steps and HOOS-JR scores over time. RESULTS: Eighty-two patients were enrolled. Seventy-four percent returned to work by week 4. Seventy-six percent of left THA patients returned to driving by week 4. At 6 weeks, 23% of survey respondents were taking pain medication and 26% were using assistive devices. Average daily steps were 1098 at week 1, 2491 at week 2, 4130 at week 3, 4850 at week 4, 5712 at week 5, and 6069 at week 6. A significant correlation (R: -0.981) was found between increased weekly steps and improved HOOS-JR scores after THA (P < .001). CONCLUSION: Defining expected recovery timelines for patients undergoing THA helps surgeons counsel their patients preoperatively. Our study demonstrates an expected pathway for recovery after THA by using modified precautions that will be more clearly outlined with ongoing clinical data analysis.

Clinical Use of Improved Diagnostic Testing for Detection of Prion Disease.

Prion diseases are difficult to recognize as many symptoms are shared among other neurologic pathologies and the full spectra of symptoms usually do not appear until late in the disease course. Additionally, many commonly used laboratory markers are non-specific to prion disease. The recent introduction of second-generation real time quaking induced conversion (RT-QuIC) has revolutionized pre-mortem diagnosis of prion disease due to its extremely high sensitivity and specificity. However, RT-QuIC does not provide prognostic data and has decreased diagnostic accuracy in some rarer, atypical prion diseases. The objective of this review is to provide an overview of the current clinical utility of fluid-based biomarkers, neurodiagnostic testing, and brain imaging in the diagnosis of prion disease and to suggest guidelines for their clinical use, with a focus on rarer prion diseases with atypical features. Recent advancements in laboratory-based testing and imaging criteria have shown improved diagnostic accuracy and prognostic potential in prion disease, but because these diagnostic tests are not sensitive in some prion disease subtypes and diagnostic test sensitivities are unknown in the event that CWD transmits to humans, it is important to continue investigations into the clinical utility of various testing modalities.

When Has a Knee or Hip Replacement Failed? A Patient Perspective.

OBJECTIVE: To define the patient perspective of what constitutes a failure of total joint replacement (TJR) in a qualitative study. METHODS: We used the nominal group technique (NGT) with participants who had undergone elective total hip replacements (THR) and/or total knee replacements (TKR) to answer the question, "When would you consider a knee or hip replacement to be a failure?" RESULTS: We performed 8 nominal groups with 42 participants, all of whom had undergone THR and/or TKR between 2016 and 2018. Of these, 48% were male, 17% were Black, 79% had college education or above, and 76% had had osteoarthritis as the underlying diagnosis. The nominated responses/themes that were ranked the highest by the participants were as follows: (1) refractory index joint pain (80 votes); (2) occurrence of postoperative adverse events (54 votes); (3) unable to resume normal activities or go back to work (38 votes); (4) little or no improvement in quality of life (35 votes); (5) early revision surgery (35 votes); (6) death (7 votes); and (7) other, including nurse or physician negligence (2 votes) and expectation-outcome mismatch (1 vote). CONCLUSION: Lack of relief of pain or restoration of function or quality of life, or the occurrence of surgical complications after TJR were defined as TJR failure by participants. Functional TJR failure seems as important or more important than surgical failure. This patient perspective emphasizing pain, function, satisfaction, adverse events, and revision as critical domain components of TJR failure independently validated their inclusion in the TJR core domain set for clinical trials in people undergoing knee or hip TJR.