Background
The BIOLOX® option system, consisting of a BIOLOX® delta ceramic femoral head with a titanium alloy adapter sleeve, is being increasingly utilized in revision hip arthroplasty. The sleeve ...protects the ceramic head from fracture and improper motion about the stem trunnion when a damaged trunnion is encountered at revision surgery. Corrosion and fretting due to metal-metal contact at the taper region of hip prosthesis create the potential of causing periprosthetic osteolysis and adverse local tissue reactions.
Questions/Purposes
The objective of this study was to identify the type and extent of damage to retrieved sleeves and ceramic heads to determine their in vivo performance.
Methods
Twenty-four ceramic heads with titanium alloy sleeves were examined. The articular and taper surfaces for each ceramic head were assessed for metal transfer using a subjective grading system. All surfaces of the 24 titanium sleeves and stem trunnions (only available for 7 of 24 cases) were assessed for corrosion and fretting using an established grading system. Scanning electron microscopy and energy dispersive X-ray analysis were conducted on representative sample of sleeves.
Results
Fretting and corrosion were higher at the inner surface of the taper sleeve than the outer sleeve. Mean fretting scores at the inner taper and outer taper sleeve surfaces were 1.8 and 1.2, respectively. The mean corrosion score at the inner taper surface was 1.8; no corrosion was observed on the outer surface of any taper sleeve. SEM and EDS analyses provided further indications of low levels of damage.
Conclusion
Fretting and corrosion were less severe than previously reported for conventional THA metal-metal taper connections, indicating that a ceramic head and titanium sleeve is a safe alternative in revision THA.
Socioeconomic factors such as poverty may mediate racial disparities in health outcomes after total hip arthroplasty (THA) and confound analyses of differences between blacks and whites.
Using a ...large institutional THA registry, we built models incorporating individual and census tract data and analyzed interactions between race and percent of population with Medicaid coverage and its association with 2-year patient-reported outcomes.
Black patients undergoing THA had worse baseline and 2-year pain and function scores compared with whites. We observed strong positive correlations between census tract Medicaid coverage and percent living below poverty (rho = 0.69; P < 0.001). Disparities in 2-year Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain and function were magnified in communities with high census tract Medicaid coverage. For blacks in these communities, 2-year WOMAC function scores were predicted to be -5.54 points lower (80.42 versus 85.96) compared with blacks in less deprived communities, a difference not observed among whites.
WOMAC pain and function 2 years after THA are similar among blacks and whites in communities with little deprivation (low percent census tract Medicaid coverage). WOMAC function at 2 years is worse among blacks in areas of higher deprivation but is not seen among whites.
Level II - Cohort Study.
To evaluate population-based systemic lupus erythematosus (SLE) arthroplasty rates and compare them with rates in patients with no inflammatory or autoimmune conditions.
Administrative hospital ...discharge databases from 10 American states were used to compare knee, hip, and shoulder arthroplasty rates from 1991 to 2005 in patients with SLE and in patients with no inflammatory or autoimmune conditions.
Arthroplasties were performed on patients with SLE (n = 4253) and patients with noninflammatory conditions (n = 2,762,660). Arthroplasty rates for patients with noninflammatory conditions almost doubled from 1991 to 2005 (124.5 cases/100,000 persons vs 247.5/100,000; p < 0.001). A similar trend was observed for SLE (0.17/100,000 vs 0.38/100,000; p < 0.001). The mean age at arthroplasty in patients with noninflammatory conditions decreased (71.5 ± 11.8 vs 69.0 ± 12.0; p < 0.001), whereas the mean age in patients with SLE increased (47.3 ± 17.0 vs 56.8 ± 16.0; p < 0.001). When stratified by age and sex, arthroplasty in cases of SLE increased in all groups except for women < 44 years old. In 1991, osteonecrosis accounted for 53% and osteoarthritis (OA) 23% of cases of SLE; by 2005 this relationship had reversed, with osteonecrosis accounting for 24% and OA 61% of cases of SLE.
From 1991 to 2005, arthroplasty rates increased in patients with SLE in similar proportions to overall joint replacement rates. The age of patients with SLE arthroplasty increased and fewer cases were due to osteonecrosis. These data suggest significant changes are occurring - patients with SLE are now living long enough to develop OA and are healthy enough to undergo elective surgery.
Our objective in this study was to examine whether stakeholders further endorse the core domain set proposed by the Outcome Measures in Rheumatology Trials (OMERACT) total joint replacement (TJR) ...working group.
We emailed a survey to 3810 hip/knee arthroplasty patients and 49 arthroplasty surgeons at a high-volume arthroplasty center to rate the importance of each core domain (i.e., pain, function, patient satisfaction, revision surgery, adverse events, and death) and two additional domains (i.e., cost and participation). Ratings were on a 1-9 scale, with 1-3 indicating limited or no importance for patients, 4-6 being important but not critical, and 7-9 being critical. We calculated median (IQR) values and compared ratings by sex, age, and participant type using the Wilcoxon rank-sum test.
The questionnaire was completed by 1295 patients (34%) and 21 surgeons (43%). Patient nonresponders were similar to responders in age (≥55 years, 85.7% vs. 88.6%), sex (female, 57.5% vs. 57.3%), and joint procedure (total hip replacement, 56.9% vs. 63.2%). Overall, all core domains and one noncore domain (i.e., participation) were confirmed as "critical" by both stakeholder groups. Cost was rated as only "important" but not "critical" by surgeons. A completed consensus for all the core domains persisted even when we stratified by sex, age, arthritis type, and the affected joint (knee vs. hip). We received suggestions for additional critical domains from 217 patients and 5 surgeons, prompting the inclusion of 2 research agenda items.
Our study confirmed a consensus rating of the OMERACT TJR core domain set as critical for patients. This broad endorsement should encourage the identification of candidate outcome instruments to further develop a TJR core measurement set that can harmonize reporting in TJR clinical trials.
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.
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.
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.
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.
Diagnostic Level II. See Instructions for Authors for a complete description of levels of evidence.
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.
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.
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).
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 IV.
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.
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.
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.
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.
Objective
Patients with rheumatoid arthritis (RA) in clinical remission may have subclinical synovial inflammation. This study was undertaken to determine the proportion of patients with RA in ...remission or with low disease activity at the time of arthroplasty who had histologic or transcriptional evidence of synovitis, and to identify clinical features that distinguished patients as having subclinical synovitis.
Methods
We compared Disease Activity Score in 28 joints (DAS28) to synovial histologic features in 135 patients with RA undergoing arthroplasty. We also compared DAS28 scores to RNA‐Seq data in a subset of 35 patients.
Results
Fourteen percent of patients met DAS28 criteria for clinical remission (DAS28 <2.6), and another 15% met criteria for low disease activity (DAS28 <3.2). Histologic analysis of synovium revealed synovitis in 27% and 31% of samples from patients in remission and patients with low disease activity, respectively. Patients with low disease activity and synovitis also exhibited increased C‐reactive protein (CRP) (P = 0.0006) and increased anti–cyclic citrullinated peptide (anti‐CCP) antibody levels (P = 0.03) compared to patients without synovitis. Compared to patients with a “low inflammatory synovium” subtype, 183 genes were differentially expressed in the synovium of patients with subclinical synovitis. The majority of these genes (86%) were also differentially expressed in the synovium of patients with clinically active disease (DAS28 ≥3.2).
Conclusion
Thirty‐one percent of patients with low clinical disease activity exhibited histologic evidence of subclinical synovitis, which was associated with increased CRP and anti‐CCP levels. Our findings suggest that synovial gene expression signatures of clinical synovitis are present in patients with subclinical synovitis.
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.
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.
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.
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.
Benefits of simultaneous bilateral total knee replacement (TKR) include lower costs, decreased hospital stay, and shorter rehabilitation. This study evaluated complications associated with ...simultaneous versus staged bilateral TKR within 12 months. We hypothesized that after controlling for comorbidities, the simultaneous group would have the highest rate of complications.
This retrospective study analyzed the Humana subset of the PearlDiver Patient Records Database. CPT 27447 and associated modifiers were used to identify patients who underwent simultaneous or staged bilateral primary TKRs. Staged bilateral TKRs were performed within 12 months and were stratified by the time between procedures. Primary outcomes were the Centers for Medicare & Medicaid Services' publicly reported complications. Risks of complications were compared using multivariate logistic regression controlling for age, gender, and comorbidities.
Seven thousand seven hundred forty-seven patients underwent simultaneous or staged bilateral TKRs between January 2007 and April 2015. There were lower odds of transfusion and all-cause 90-day readmission but higher odds of mechanical complications and infection for all staged groups compared to the simultaneous. Patients whose staged surgeries were ≪3 months apart had significantly higher odds of undergoing manipulation under anesthesia (MUA).
Higher rates of blood transfusion and readmission were associated with simultaneous bilateral TKR, while higher rates of mechanical complications and infection were associated with staged bilateral TKR. MUA risk was highest in patients staged ≪3 months apart. While there are inherent risks to simultaneous bilateral TKR, surgeons and patients should also be aware of risks associated with staging the procedures.
III