Does Preoperative Pharmacogenomic Testing of Patients Undergoing TKA Improve Postoperative Pain? A Randomized Trial.

BACKGROUND: Pharmacogenomics is an emerging and affordable tool that may improve postoperative pain control. One challenge to successful pain control is the large interindividual variability among analgesics in their efficacy and adverse drug events. Whether preoperative pharmacogenomic testing is worthwhile for patients undergoing TKA is unclear. QUESTIONS/PURPOSES: (1) Are the results of preoperative pharmacogenetic testing associated with lower postoperative pain scores as measured by the Overall Benefit of Analgesic Score (OBAS)? (2) Do the results of preoperative pharmacogenomic testing lead to less total opioids given? (3) Do the results of preoperative pharmacogenomic testing lead to changes in opioid prescribing patterns? METHODS: Participants of this randomized trial were enrolled from September 2018 through December 2021 if they were aged 18 to 80 years and were undergoing primary TKA under general anesthesia. Patients were excluded if they had chronic kidney disease, a history of chronic pain or narcotic use before surgery, or if they were undergoing robotic surgery. Preoperatively, patients completed pharmacogenomic testing (RightMed, OneOME) and a questionnaire and were randomly assigned to the experimental group or control group. Of 99 patients screened, 23 were excluded, one before randomization; 11 allocated patients in each group did not receive their allocated interventions for reasons such as surgery canceled, patients ultimately undergoing spinal anesthesia, and change in surgery plan. Another four patients in each group were excluded from the analysis because they were missing an OBAS report. This left 30 patients for analysis in the control group and 38 patients in the experimental group. The control and experimental groups were similar in age, gender, and race. Pharmacogenomic test results for patients in the experimental group were reviewed before surgery by a pharmacist, who recommended perioperative medications to the clinical team. A pharmacist also assessed for clinically relevant drug-gene interactions and recommended drug and dose selection according to guidelines from the Clinical Pharmacogenomics Implementation Consortium for each patient enrolled in the study. Patients were unaware of their pharmacogenomic results. Pharmacogenomic test results for patients in the control group were not reviewed before surgery; instead, standard perioperative medications were administered in adherence to our institutional care pathways. The OBAS (maximum 28 points) was the primary outcome measure, recorded 24 hours postoperatively. A two-sample t-test was used to compare the mean OBAS between groups. Secondary measures were the mean 24-hour pain score, total morphine milligram equivalent, and frequency of opioid use. Postoperatively, patients were assessed for pain with a VAS (range 0 to 10). Opioid use was recorded preoperatively, intraoperatively, in the postanesthesia care unit, and 24 hours after discharge from the postanesthesia care unit. Changes in perioperative opioid use based on pharmacogenomic testing were recorded, as were changes in prescription patterns for postoperative pain control. Preoperative characteristics were also compared between patients with and without various phenotypes ascertained from pharmacogenomic test results. RESULTS: The mean OBAS did not differ between groups (mean ± SD 4.7 ± 3.7 in the control group versus 4.2 ± 2.8 in the experimental group, mean difference 0.5 [95% CI -1.1 to 2.1]; p = 0.55). Total opioids given did not differ between groups or at any single perioperative timepoint (preoperative, intraoperative, or postoperative). We found no difference in opioid prescribing pattern. After adjusting for multiple comparisons, no difference was observed between the treatment and control groups in tramadol use (41% versus 71%, proportion difference 0.29 [95% CI 0.05 to 0.53]; nominal p = 0.02; adjusted p > 0.99). CONCLUSION: Routine use of pharmacogenomic testing for patients undergoing TKA did not lead to better pain control or decreased opioid consumption. Future studies might focus on at-risk populations, such as patients with chronic pain or those undergoing complex, painful surgical procedures, to test whether pharmacogenomic results might be beneficial in certain circumstances. LEVEL OF EVIDENCE: Level I, therapeutic study.

Differences in Reimbursements, Procedural Volumes, and Patient Characteristics Based on Surgeon Gender in Total Hip Arthroplasty.

BACKGROUND: Prior studies have suggested there may be differences in reimbursement and practice patterns by gender. The purpose of this study was to comprehensively evaluate differences in reimbursement, procedural volume, and patient characteristics in total hip arthroplasty (THA) between men and women surgeons from 2013 to 2021. METHODS: The Medicare Physician and Other Practitioners database from 2013 to 2021 was queried. Inflation-adjusted reimbursement, procedural volume, surgeon information, and patient demographics were extracted for surgeons performing over 10 primary THAs each year. Wilcoxon, t-tests, and multivariate linear regressions were utilized to compare men and women surgeons. RESULTS: Only 1.4% of THAs billed to Medicare between 2013 and 2021 were billed by women surgeons. Men surgeons earned significantly greater reimbursement nationally in 2021 compared to women surgeons per THA ($1,018.56 versus $954.17, P = .03), but no difference was found when assessing each region separately. Reimbursement declined at similar rates for both men and women surgeons (-18.3 versus -19.8%, P = .38). An increase in the proportion of women surgeons performing THA between 2013 and 2021 was seen in all regions except the South. In 2021, the proportion of all THAs performed by women surgeons was highest in the West (3.5%) and lowest in the South (1.0%). Women surgeons had comparable patient populations in terms of age, race, comorbidity status, and Medicaid eligibility to their men counterparts, but performed significantly fewer services per beneficiary (5.6 versus 8.1, P < .001) and fewer unique services (51.1 versus 69.6, P < .001). CONCLUSIONS: Average reimbursement per THA has declined at a similar rate for men and women physicians between 2013 and 2021. Women's representation in THA surgery nationwide has nearly doubled between 2013 and 2021, with the greatest increase in the West. However, there are notable differences in billing practices between genders.

Geographical Differences in Surgeon Reimbursement, Volume, and Patient Characteristics in Primary Total Hip Arthroplasty.

BACKGROUND: The purpose of this study was to evaluate changes in regional and national variations in reimbursement to arthroplasty surgeons, procedural volumes, and patient populations for total hip arthroplasty (THA) from 2013 to 2021. METHODS: The Medicare Physician and Other Practitioners database was queried for all billing episodes of primary THA for each year between 2013 and 2021. Inflation-adjusted surgeon reimbursement, procedural volume, physician address, and patient characteristics were extracted for each year. Data were stratified geographically based on the United States Census regions and rural-urban commuting codes. Kruskal-Wallis and multivariable regressions were utilized. RESULTS: Between 2013 and 2021, the overall THA volume and THAs per surgeon increased at the highest rate in the West (+48.2%, +20.2%). A decline in surgeon reimbursement was seen in all regions, most notably in the Midwest (-20.3%). Between 2013 and 2021, the average number of Medicare beneficiaries per surgeon declined by 12.6%, while the average number of services performed per beneficiary increased by 18.2%. In 2021, average surgeon reimbursement was the highest in the Northeast ($1,081.15) and the lowest in the Midwest ($988.03) (P < .001). Metropolitan and rural areas had greater reimbursement than micropolitan and small towns (P < .001). Patient age, race, sex, Medicaid eligibility, and comorbidity profiles differ between regions. Increased patient comorbidities, when controlling for patient characteristics, were associated with lower reimbursement in the Northeast and West (P < .01). CONCLUSIONS: Total hip arthroplasty (THA) volume and reimbursement differ between US regions, with the Midwest exhibiting the lowest increase in volume and greatest decline in reimbursement throughout the study period. Alternatively, the West had the greatest increase in THAs per surgeon. Patient comorbidity profiles differ between regions, and increased patient comorbidity is associated with decreased reimbursement in the Northeast and the West. This information is important for surgeons and policymakers as payment models regarding reimbursement for arthroplasty continue to evolve.

Risk Versus Reward: Hospitals Incentivized More Than Surgeons to Care for Riskier Arthroplasty Patients.

BACKGROUND: The purpose of this study was to assess the relationship between risk and reimbursement for both surgeons and hospitals among Medicare patients undergoing primary total joint arthroplasty (TJA). METHODS: The "2021 Medicare Physician and Other Provider" and "2021 Medicare Inpatient Hospitals" files were used. Patient comorbidity profiles were collected, including the mean patient hierarchal condition category (HCC) risk score. Surgeon data included all primary TJA procedures (inpatient and outpatient) billed to Medicare in 2021, while hospital data included all such inpatient episodes. Surgeon and hospital reimbursements were collected. All episodes were split into a "sicker cohort" with an HCC risk score of 1.5 or more and a "healthier cohort" with HCC risk scores less than 1.5. Variables were compared across cohorts. RESULTS: In 2021, 386,355 primary total hip and knee arthroplasty procedures were billed to Medicare and were included. The mean surgeon reimbursement among the sicker cohort was $1,021.91, which was less than for the healthier cohort of $1,060.13 (P < .001). Meanwhile, for the hospital analysis, 112,012 Medicare TJA patients were admitted as inpatients and included. The mean reimbursement to hospitals was significantly greater for the sicker cohort at $13,950.66, compared to the healthier cohort of $8,430.46. For both analyses, the sicker patient cohorts had a significantly higher rate of all comorbidities assessed (P < .001). CONCLUSIONS: This study demonstrates that mean surgeon reimbursement was lower for primary TJA among sicker patients in comparison to their healthier counterparts, while hospital reimbursement was higher for sicker patients. This represents a discrepancy in the incentivization of care for complex patients, as hospitals receive increased remuneration for taking on extra risk, while surgeons get paid less on average for performing TJA on sicker patients. Such data should inform future policy to assure continued access to arthroplasty care among complex patients.

Rheumatoid Arthritis Is Not a Contraindication to Unicompartmental Knee Arthroplasty.

BACKGROUND: Rheumatoid arthritis (RA) has historically been considered a contraindication for unicompartmental knee arthroplasty (UKA). However, the widespread use of disease-modifying antirheumatic drugs has substantially improved the management of RA and prevented disease progression. The objective of this study was to ascertain whether RA impacts UKA revision-free survivorship. METHODS: Patients undergoing UKA from 2010 to 2021 were identified in an administrative claims database (n = 105,937) using Current Procedural Terminology code 27446. All patients who underwent UKA who had a diagnosis of RA with a minimum of 2-year follow-up (n = 1,422) were propensity score matched based on age, sex, and Elixhauser Comorbidity Index to those who did not have RA (n = 1,422). Laterality was identified using the 10th Revision of International Classification of Diseases codes. The primary outcome was ipsilateral revision to total knee arthroplasty (TKA) within 2 years, and the secondary outcome was ipsilateral revision at any time. RESULTS: Among the 1,422 patients who had a UKA and a diagnosis of RA, 37 patients (2.6%) underwent conversion to TKA within 2 years, and 48 patients (3.4%) underwent conversion to TKA at any point. In comparison, 28 patients (2.0%) in the propensity-matched control group underwent conversion to TKA within 2 years, and 40 patients (2.8%) underwent conversion to TKA at any point. Statistical analysis revealed no significant difference in conversion to TKA between patients who had and did not have RA, either within 2 years (P = .31) or anytime (P = .45). CONCLUSIONS: Patients who had RA and underwent UKA did not have an increased risk of revision to TKA compared to those who did not have RA. This may indicate that modern management of RA could allow for expanded UKA indications for RA patients.

Low Risk of Periprosthetic Joint Infection After Aseptic Revision Total Knee Arthroplasty With Intraosseous Vancomycin.

BACKGROUND: Aseptic revisions are the most common reason for revision total knee arthroplasty (rTKA). Previous literature reports early periprosthetic joint infection (PJI) rates after aseptic rTKA to range from 3 to 9.4%. Intraosseous (IO) regional administration of vancomycin has previously been shown to produce high local tissue concentrations in primary and rTKA. However, no data exist on the effect of prophylactic IO vancomycin on early PJI rates in the setting of aseptic rTKA. The aim of this study was to determine the following: (1) what is the rate of early PJI during the first year after surgery in aseptic rTKA performed with IO vancomycin; and (2) how does this compare to previously published PJI rates after rTKA. METHODS: A consecutive series of 117 cases were included in this study who underwent rTKA between January 2016 and March 2022 by 1 of 2 fellowship-trained adult reconstruction surgeons and received IO vancomycin at the time of surgery in addition to standard intravenous antibiotic prophylaxis. Rates of PJI at 3 months, 1 year, and the final follow-up were evaluated and compared to prior literature. RESULTS: Follow-up at 3 months was available for 116 of the 117 rTKAs, with 1 lost to follow-up. The rate of PJI was 0% at 3 months postoperatively. Follow-up at 1 year was obtained for 113 of the 117 rTKAs, and the PJI rate remained 0%. The rate of PJI at the final follow-up of ≥ 1 year was 0.88% (95% confidence interval: -0.84 to 2.61). Previous literature reports PJI rates in aseptic rTKA to range from 3 to 9.4%. CONCLUSIONS: Dual prophylactic antibiotics with IO vancomycin in conjunction with intravenous cephalosporins or clindamycin were associated with a substantial reduction in early PJI compared to prior published literature. These data supplement the early evidence about the potential clinical benefits of IO vancomycin for infection prevention in high-risk cases. LEVEL OF EVIDENCE: Level III, therapeutic study.

Clostridium difficile Infection Prior to Total Hip Arthroplasty Independently Increases the Risk of Periprosthetic Joint Infection.

BACKGROUND: Periprosthetic joint infection (PJI) following total hip arthroplasty (THA) is associated with major morbidity. There may be a link between the gut microbiome and an individual's overall immune system. A Clostridium difficile (C. difficile) infection portends poor gut microbiome health and has been previously associated with increased 90-day complication rates in total joint arthroplasty (TJA). The purpose of this study was to determine the effect of a previous history of C. difficile infection within 2 years of undergoing THA on PJI within 2 years postoperatively. METHODS: Patients undergoing THA from 2010 to 2021 were identified in a patient claims database (n = 770,075). Patients who had active records 2 years before and after THA as well as a history of C. difficile infection within 2 years prior to THA (n = 1,836) were included and propensity matched to a control group using age, sex, and Elixhauser comorbidity index. The primary outcome was the 2-year incidence of postoperative PJI. The exposed C. difficile infection cohort was stratified into 4 groups based on the time proximity of the C. difficile infection. Chi-square tests and logistic regressions were used to compare the groups. RESULTS: A C. difficile infection anytime within 2 years prior to total hip arthroplasty was independently associated with higher odds of PJI (OR [odds ratio]: 1.49 [95% CI (confidence interval) 1.09 to 2.02, P = .014]). Proximity of C. difficile infection to arthroplasty was associated with increased risk of PJI (infection 0 to 3 months before THA: OR 2.01 [95% CI 1.23 to 3.20], infection 3 to 6 months before THA: OR 1.84 [95% CI 1.06 to 3.04], infection 6 to 12 months before THA: OR 1.10 [95% CI 0.65 to 1.77], infection 1 to 2 years before THA: OR 1.40 [95% CI 0.94 to 2.06]). CONCLUSIONS: A C. difficile infection prior to THA is an independent risk factor for PJI. Proximity of C. difficile infection is associated with increased risk of PJI. Future investigations should evaluate how to adequately optimize patients prior to THA and pursue strategies to determine appropriate timing for proceeding with THA.

Discordance Abounds in Minimum Clinically Important Differences in THA: A Systematic Review.

BACKGROUND: The minimum clinically important difference (MCID) is intended to detect a change in a patient-reported outcome measure (PROM) large enough for a patient to appreciate. Their growing use in orthopaedic research stems from the necessity to identify a metric, other than the p value, to better assess the effect size of an outcome. Yet, given that MCIDs are population-specific and that there are multiple calculation methods, there is concern about inconsistencies. Given the increasing use of MCIDs in total hip arthroplasty (THA) research, a systematic review of calculated MCID values and their respective ranges, as well as an assessment of their applications, is important to guide and encourage their use as a critical measure of effect size in THA outcomes research. QUESTIONS/PURPOSES: We systematically reviewed MCID calculations and reporting in current THA research to answer the following: (1) What are the most-reported PROM MCIDs in THA, and what is their range of values? (2) What proportion of studies report anchor-based versus distribution-based MCID values? (3) What are the most common methods by which anchor-based MCID values are derived? (4) What are the most common derivation methods for distribution-based MCID values? (5) How do the reported medians and corresponding ranges compare between calculation methods for each PROM? METHODS: The EMBASE, MEDLINE, and PubMed databases were systematically reviewed from inception through March 2022 for THA studies reporting an MCID value for any PROMs. Two independent authors reviewed articles for inclusion. All articles calculating new PROM MCID scores after primary THA were included for data extraction and analysis. MCID values for each PROM, MCID calculation method, number of patients, and study demographics were extracted from each article. In total, 30 articles were included. There were 45 unique PROMs for which 242 MCIDs were reported. These studies had a total of 1,000,874 patients with a median age of 64 years and median BMI of 28.7 kg/m 2 . Women made up 55% of patients in the total study population, and the median follow-up period was 12 months (range 0 to 77 months). The overall risk of bias was assessed as moderate using the modified Methodological Index for Nonrandomized Studies criteria for comparative studies (the mean score for comparative papers in this review was 18 of 24, with higher scores representing better study quality) and noncomparative studies (for these, the mean score was 10 of a possible 16 points, with higher scores representing higher study quality). Calculated values were classified as anchor-based, distribution-based, or not reported. MCID values for each PROM, MCID calculation method, number of patients, and study demographics were extracted from each study. Anchor-based and distribution-based MCIDs were compared for each unique PROM using a Wilcoxon rank sum test, given the non-normal distribution of values. RESULTS: The Oxford Hip Score (OHS) and the Hip Injury and Osteoarthritis Score (HOOS) Pain and Quality of Life subscore MCIDs were the most frequently reported, comprising 12% (29 of 242), 8% (20 of 242), and 8% (20 of 242), respectively. The EuroQol VAS (EQ-VAS) was the next-most frequently reported (7% [17 of 242]) followed by the EuroQol 5D (EQ-5D) (7% [16 of 242]). The median anchor-based value for the OHS was 9 (IQR 8 to 11), while the median distribution-based value was 6 (IQR 5 to 6). The median anchor-based MCID values for HOOS Pain and Quality of Life were 33 (IQR 28 to 35) and 25 (14 to 27), respectively; the median distribution-based values were 10 (IQR 9 to 10) and 13 (IQR 10 to 14), respectively. Thirty percent (nine of 30) of studies used an anchor-based method to calculate a new MCID, while 40% (12 of 30) used a distribution-based technique. Thirty percent of studies (nine of 30) calculated MCID values using both methods. For studies reporting an anchor-based calculation method, a question assessing pain relief, satisfaction, or quality of life on a five-point Likert scale was the most commonly used anchor (30% [eight of 27]), followed by a receiver operating characteristic curve estimation (22% [six of 27]). For studies using distribution-based calculations, the most common method was one-half the standard deviation of the difference between preoperative and postoperative PROM scores (46% [12 of 26]). Most reported median MCID values (nine of 14) did not differ by calculation method for each unique PROM (p > 0.05). The OHS, HOOS JR, and HOOS Function, Symptoms, and Activities of Daily Living subscores all varied by calculation method, because each anchor-based value was larger than its respective distribution-based value. CONCLUSION: We found that MCIDs do not vary very much by calculation method across most outcome measurement tools. Additionally, there are consistencies in MCID calculation methods, because most authors used an anchor question with a Likert scale for the anchor-based approach or used one-half the standard deviation of preoperative and postoperative PROM score differences for the distribution-based approach. For some of the most frequently reported MCIDs, however, anchor-based values tend to be larger than distribution-based values for their respective PROMs. CLINICAL RELEVANCE: We recommend using a 9-point increase as the MCID for the OHS, consistent with the median reported anchor-based value derived from several high-quality studies with large patient groups that used anchor-based approaches for MCID calculations, which we believe are most appropriate for most applications in clinical research. Likewise, we recommend using the anchor-based 33-point and 25-point MCIDs for the HOOS Pain and Quality of Life subscores, respectively. We encourage using anchor-based MCID values of WOMAC Pain, Function, and Stiffness subscores, which were 29, 26, and 30, respectively.

There are Considerable Inconsistencies Among Minimum Clinically Important Differences in TKA: A Systematic Review.

BACKGROUND: Patient-reported outcome measures (PROMs) are frequently used to assess the impact of total knee arthroplasty (TKA) on patients. However, mere statistical comparison of PROMs is not sufficient to assess the value of TKA to the patient, especially given the risk profile of arthroplasty. Evaluation of treatment effect sizes is important to support the use of an intervention; this is often quantified with the minimum clinically important difference (MCID). MCIDs are unique to specific PROMs, as they vary by calculation methodology and study population. Therefore, a systematic review of calculated MCID values, their respective ranges, and assessment of their applications is important to guide and encourage their use as a critical measure of effect size in TKA outcomes research. QUESTIONS/PURPOSES: In this systematic review of MCID calculations and reporting in primary TKA, we asked: (1) What are the most frequently reported PROM MCIDs and their reported ranges in TKA? (2) What proportion of studies report distribution- versus anchor-based MCID values? (3) What are the most common methods by which these MCID values are derived for anchor-based values? (4) What are the most common derivation methods for distribution-based values? (5) How do the reported medians and corresponding interquartile ranges (IQR) compare between calculation methods for each PROM? METHODS: Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, a systematic review was conducted using the PubMed, EMBASE, and MEDLINE databases from inception through March 2022 for TKA articles reporting an MCID value for any PROMs. Two independent reviewers screened articles for eligibility, including any article that calculated new MCID values for PROMs after primary TKA, and extracted these data for analysis. Overall, 576 articles were identified, 38 of which were included in the final analysis. These studies had a total of 710,128 patients with a median age of 67.7 years and median BMI of 30.9 kg/m 2 . Women made up more than 50% of patients in most studies, and the median follow-up period was 17 months (range 0.25 to 72 months). The overall risk of bias was assessed as moderate using the Jadad criteria for one randomized controlled trial (3 of 5 ideal global score) and the modified Methodological Index for Non-randomized Studies criteria for comparative studies (mean 17.2 ± 1.8) and noncomparative studies (mean 9.6 ± 1.3). There were 49 unique PROMs for which 233 MCIDs were reported. Calculated values were classified as anchor-based, distribution-based, or not reported. MCID values for each PROM, MCID calculation method, number of patients, and study demographics were extracted from each study. Anchor-based and distribution-based MCIDs were compared for each unique PROM using a Wilcoxon rank sum test given non-normal distribution of values. RESULTS: The WOMAC Function and Pain subscores were the most frequently reported MCID value, comprising 9% (22 of 233) and 9% (22 of 233), respectively. The composite Oxford Knee Score (OKS) was the next most frequently reported (9% [21 of 233]), followed by the WOMAC composite score (6% [13 of 233]). The median anchor-based values for WOMAC Function and Pain subscores were 23 (IQR 16 to 33) and 25 (IQR 14 to 31), while the median distribution-based values were 11 (IQR 10.8 to 11) and 22 (IQR 17 to 23), respectively. The median anchor-based MCID value for the OKS was 6 (IQR 4 to 7), while the distribution-based value was 7 (IQR 5 to 10). Thirty-nine percent (15 of 38) used an anchor-based method to calculate a new MCID, while 32% (12 of 38) used a distribution-based technique. Twenty-nine percent of studies (11 of 38) calculated MCID values using both methods. For studies reporting an anchor-based calculation method, a question assessing patient satisfaction, pain relief, or quality of life along a five-point Likert scale was the most commonly used anchor (40% [16 of 40]), followed by a receiver operating characteristic curve estimation (25% [10 of 40]). For studies using distribution-based calculations, all articles used a measure of study population variance in their derivation of the MCID, with the most common method reported as one-half the standard deviation of the difference between preoperative and postoperative PROM scores (45% [14 of 31]). Most reported median MCID values (15 of 19) did not differ by calculation method for each unique PROM (p > 0.05) apart from the WOMAC Function component score and the Knee Injury and Osteoarthritis Outcome Score Pain and Activities of Daily Living subscores. CONCLUSION: Despite variability of MCIDs for each PROM, there is consistency in the methodology by which MCID values have been derived in published studies. Additionally, there is a consensus about MCID values regardless of calculation method across most of the PROMs we evaluated. CLINICAL RELEVANCE: Given their importance to treatment selection and patient safety, authors and journals should report MCID values with greater consistency. We recommend using a 7-point increase as the MCID for the OKS, consistent with the median reported anchor-based value derived from several high-quality studies with large patient groups that used anchor-based approaches for MCID calculation, which we believe are most appropriate for most applications in clinical research. Likewise, we recommend using a 10-point to 15-point increase for the MCID of composite WOMAC, as the median value was 12 (IQR 10 to 17) with no difference between calculation methods. We recommend use of median reported values for WOMAC function and pain subscores: 21 (IQR 15 to 33) and 23 (IQR 13 to 29), respectively.

The Current Relationship Between Surgeon Reimbursement and Patient Complexity in Arthroplasty-A Risk-Payment Analysis of All Primary Joint Replacements Billed to Medicare in 2019.

BACKGROUND: The purpose of this study was to assess surgeon reimbursement among total joint arthroplasty (TJA) patients who had differing risk profiles within the Medicare population. METHODS: The "2019 Medicare Physician and Other Provider" file was utilized. In 2019, 441,584 primary total hip and knee arthroplasty procedures were billed to Medicare Part B. All episodes were included. Patient demographics and comorbidity profiles were collected for all patients. Additionally, mean patient hierarchal condition category (HCC) risk scores and physician reimbursements were collected. All procedure episodes were split into 2 cohorts; those with an HCC risk score of 1.5 or greater, and those with patient HCC risk scores less than 1.5. Variables were averaged for each cohort and compared. RESULTS: The mean reimbursement across all procedures was $1,068.03. For the sicker patient cohort with a mean HCC risk score of 1.5 or greater, there was a significantly higher rate of all comorbidities compared to the cohort with HCC risk score under 1.5. The mean payment across the sicker cohort was $1,059.21, while the mean payment among the cohort with HCC risk score under 1.5 was 1,073.32 (P = .032). CONCLUSION: This study demonstrates that for Medicare patients undergoing primary TJA in 2019, the mean surgeon reimbursement was lower for primary TJA among sick patients in comparison to their healthier counterparts, although it is difficult to ascertain the impact of this discrepancy. As alternative payment models continue to undergo evaluation and development, these data will be important for the potential advancement of more equitable reimbursement models in arthroplasty care, specifically regarding surgeon reimbursement and possible risk adjustment within such models.

A Randomized Controlled Trial of Kinematically and Mechanically Aligned Total Knee Arthroplasties: Long-Term Follow-Up.

BACKGROUND: The optimal alignment technique for total knee arthroplasty (TKA) remains controversial. We previously reported 6-month and 2-year results of a randomized controlled trial comparing kinematically versus mechanically aligned TKA. In the present study, we report the mean 13-year (range, 12.6-14.4) follow-up results from this trial. METHODS: The original cohort included 88 TKAs (44 kinematically aligned using patient-specific guides and 44 mechanically aligned using conventional instrumentation), performed from 2008 to 2009. After institutional review board approval, the health records of the original 88 patients were queried. Revisions, reoperations, and complications were recorded. There were 26 patients who died, leaving 62 patients for follow-up. Of these, 48 patients (77%) were successfully contacted via phone. Reoperations and complications were documented. Furthermore, a battery of patient-reported outcome measures (PROMs) (including Western Ontario and McMaster University Index, Oxford Knee Score, Knee Injury and Osteoarthritis Outcome Score Junior, Forgotten Joint Score, Modified-Single Assessment Numerical Evaluation, and patient satisfaction) were obtained. RESULTS: Of the original 88 patients in the study, 15 patients had at least one reoperation (17%) and 5 patients had undergone complete revision surgery (6%). There was no difference between the 2 alignment methods for major and minor reoperations (P = .66). The kinematically aligned total knees self-reported a nonstatistically significant (P = .16) improved satisfaction (96% versus 82%), but no difference in other PROMs compared to mechanically aligned TKAs. CONCLUSION: Kinematically aligned TKA demonstrates excellent mean 13-year results, comparable to mechanically aligned TKA with similar reoperations, complications, and PROMs.

Risk Factors in Patients Who Had Prior Renal or Liver Transplant Undergoing Primary Total Knee Arthroplasty.

BACKGROUND: More solid organ transplant (SOT) patients are undergoing total knee arthroplasty (TKA). This study identifies risk factors for complications, implant survivorship, and mortality in TKA patients who had prior SOT. METHODS: We identified 176 TKAs in patients who had prior SOT. Of these, 77 had a prior renal (RT), 77 had a prior liver (LT) transplant, and 22 had multiple prior transplants (MT). Median survival was estimated using Kaplan-Meier. Univariate analyses were assessed with mixed-effects logistic regressions for complications and Cox-regressions for mortality. Median follow-up was 63 months (range, 24 to 109). RESULTS: At least one acute medical complication occurred in 25, 13, and 27% of cases with prior RT, LT, and MT, respectively (P = .12). None of the variables were significantly associated with acute medical complications. At least one surgical complication occurred in 14, 13 and 14% of cases with prior RT, LT, and MT, respectively (P = 1). Vitamin D supplementation (Odds Ratio [OR] = 0.38, P < .03) was associated with lower risk of surgical complications. Reoperation and revision rates were 5 and 3%, respectively. Older age at time of transplantation and greater level of serum creatinine at time of TKA were associated with lower risk (OR = 0.96, P = .01), and higher risk of reoperation (OR = 4.9, P = .01), respectively. Coronary artery disease was associated with higher mortality (Hazard Ratio = 2.35, P = .01). CONCLUSIONS: Vitamin D was associated with lower surgical complications, whereas a younger age at time of transplantation increased the risk of reoperation. Additionally, SOT patients with coronary artery disease demonstrated higher mortality after TKA.

What Is the Duration of Irrigation? An In Vitro Study of the Minimum Exposure Time to Eradicate Bacteria With Irrigation Solutions.

BACKGROUND: Antiseptic irrigation solutions are commonly used by arthroplasty surgeons to reduce intraoperative bacterial colonization with the goal of reducing postoperative infections in the setting of primary total joint arthroplasty. Currently, the minimum irrigation time to eliminate common microbes implicated in periprosthetic joint infection is unknown. We sought to determine the minimum effective exposure time required to prevent growth of Staphylococcus aureus, Staphylococcus epidermidis, and Cutibacterium acnes with common antiseptic solutions. METHODS: S aureus, S epidermidis, and C acnes cultures were treated with povidone-iodine (0.35%), chlorhexidine (0.05%), sodium hypochlorite (0.5%), polyhexamethylene biguanide, and an acetic acid-based solution for 15, 30, 60, 90, and 120 seconds in triplicate. Bacterial growth was quantified using the drop plate method. Failure to eliminate all bacteria was considered "not effective" at that time point. RESULTS: Povidone-iodine 0.35% (Betadine), sodium hypochlorite 0.5% (HySept), and acetic acid (Bactisure) eradicated all bacterial growth after 90 seconds of treatment, and as low as 15 seconds in S aureus and C acnes (Betadine) or S epidermidis (Bactisure). Polyhexamethylene biguanide (Prontosan) required 90 seconds for elimination of S aureus and S epidermidis, and 120 seconds for C acnes. Chlorhexidine 0.05% (Irrisept) did eliminate S epidermidis at 120 seconds but did not effectively eradicate S aureus or C acnes. CONCLUSION: All tested antiseptic solutions demonstrated successful eradication of all bacterial growth in under 2 minutes of treatment time except chlorhexidine. Povidone-iodine may require the shortest duration of treatment time to successfully eradicate common bacteria.

Higher Tissue Concentrations of Vancomycin Achieved With Low-Dose Intraosseous Injection Versus Intravenous Despite Limited Tourniquet Duration in Primary Total Knee Arthroplasty: A Randomized Trial.

BACKGROUND: Vancomycin use has been suggested in high risk patients undergoing total knee arthroplasty (TKA). Previous literature has shown that a lower dose (500 mg) of vancomycin given by intraosseous regional administration (IORA) achieves tissue concentrations 4-10 times higher than intravenous (IV) administration. There is increasing interest in performing TKA with limited tourniquet inflation time. The purpose of this study is to evaluate whether IORA of vancomycin can achieve effective tissue concentrations with limited tourniquet inflation time. METHODS: Based on prior power calculations, 24 patients undergoing primary TKA were randomized into 2 groups. Group IV-Systemic received weight-based (15 mg/kg) vancomycin with the tourniquet inflated for cementation only. Group IORA received 500 mg vancomycin via IORA after tourniquet inflation which remained inflated for 10 minutes, then reinflated for cementation only. Vancomycin concentrations from tissue, serum, and drain fluid were compared between the 2 groups. RESULTS: Median vancomycin concentrations in tissue were significantly higher (5-15 times) at all time points in the IORA group. Concentrations in fat at the time of wound closure, after the tourniquet had been deflated for most of the procedure, were 5.2 µg/g in Group IV-Systemic and 33.1 µg/g in Group IORA (P < .001). Median bone concentrations taken just prior to cementation were 7.9 µg/g in Group IV-Systemic and 21.8 µg/g in Group IORA (P = .006). There were no complications related to IORA. CONCLUSION: For surgeons who wish to limit tourniquet time and when indicated to use vancomycin, low-dose vancomycin IORA achieves tissue concentrations 5-15 times higher than those achieved by IV administration. LEVEL OF EVIDENCE: Level 1 therapeutic randomized trial.

The Efficacy and Safety of Periarticular Injection in Total Joint Arthroplasty: A Direct Meta-Analysis.

BACKGROUND: Periarticular injection (PAI) is administered intraoperatively to help reduce postoperative pain and opioid consumption after primary total joint arthroplasty (TJA). The purpose of this study was to evaluate the efficacy and safety of PAI in primary TJA to support the combined clinical practice guidelines of the American Association of Hip and Knee Surgeons, American Academy of Orthopaedic Surgeons, Hip Society, Knee Society, and American Society of Regional Anesthesia and Pain Medicine. METHODS: The MEDLINE, Embase, and Cochrane Central Register of Controlled Trials databases were searched for studies published prior to March 2020 on PAI in TJA. All included studies underwent qualitative and quantitative homogeneity testing followed by a systematic review and direct comparison meta-analysis to assess the efficacy and safety of PAI. RESULTS: Three thousand six hundred and ninety nine publications were critically appraised to provide 60 studies regarded as the best available evidence for an analysis. The meta-analysis showed that intraoperative PAI reduces postoperative pain and opioid consumption. Adding ketorolac or a corticosteroid to a long-acting local anesthetic (eg, ropivacaine or bupivacaine) provides an additional benefit. There is no difference between liposomal bupivacaine and other nonliposomal long-acting local anesthetics. Morphine does not provide any additive benefit in postoperative pain and opioid consumption and may increase postoperative nausea and vomiting. There is insufficient evidence to draw conclusions on the use of epinephrine and clonidine. CONCLUSION: Strong evidence supports the use of a PAI with a long-acting local anesthetic to reduce postoperative pain and opioid consumption. Adding a corticosteroid and/or ketorolac to a long-acting local anesthetic further reduces postoperative pain and may reduce opioid consumption. Morphine has no additive effect and there is insufficient evidence on epinephrine and clonidine.

A Comprehensive Monetary Analysis of Inpatient Total Hip and Knee Arthroplasties Billed to Medicare by Hospitals: 2011-2017.

BACKGROUND: Total joint arthroplasty (TJA) has been a recent target of reimbursement reform. As such, the purpose of this study was to evaluate trends in Medicare reimbursement to hospitals for TJA patients from 2011 to 2017. METHODS: The Inpatient Utilization and Payment Public Use File was queried for all primary total hip and knee arthroplasty episodes. This file includes all services billed to Medicare via the Inpatient Prospective Payment System. Extracted data included hospital charges and amount paid by Medicare. All data were adjusted for inflation to 2017 US dollars. Multiple linear mixed-model regression analyses were conducted to assess change over time, and geo-modelling was used to represent reimbursement by location. RESULTS: A total of 3,368,924 primary TJA procedures were billed to Medicare by hospitals from 2011 to 2017 and included in the study. The mean inflation-adjusted Medicare payment to hospitals for DRG 469 decreased from $22,783.66 to $19,604.62 per procedure (-$3179.04; -14.0%; P < .001) and decreased from $13,290.79 to $11,771.54 for DRG 470 (-$1519.25; -11.4%, P = .011) from 2011 to 2017. Meanwhile, the mean charge submitted by hospitals increased by $6483.39 and $5115.60 for DRGs 469 and 470, respectively (+7.4% for 469, +9.3% for 470; P < .001). Medicare reimbursement to hospitals varied by state. CONCLUSION: During the study period, the mean Medicare reimbursement to hospitals decreased for TJA from 2011 to 2017. Meanwhile, the average charge submitted by hospitals increased. As alternative payment models continue to undergo evaluation and development, these data are important for the advancement of more agreeable reimbursement models in arthroplasty care.

Temporal Analysis of Medicare Physician Reimbursement and Procedural Volume for all Hip and Knee Arthroplasty Procedures Billed to Medicare Part B From 2000 to 2019.

BACKGROUND: The purpose of this study was to evaluate trends in annual arthroplasty volume among the Medicare population, as well as assess true Medicare reimbursement to physicians for all hip and knee arthroplasty procedures billed to Medicare since year 2000. METHODS: The publicly available Medicare Part B National Summary Data File from years 2000 to 2019 was utilized. Collected data included true physician reimbursements for all primary total hip and knee, unicompartmental knee, and revision hip/knee arthroplasty procedures from 2000 to 2019. Monetary data was adjusted for inflation to year 2019 dollars. Change was assessed and compared by procedure type. RESULTS: From 2000 to 2019, physicians billed Medicare Fee-for-service for 8,363,821 hip and knee arthroplasty procedures. During this time, the annual number of included arthroplasty procedures billed to Medicare increased by 100%. From 2000 to 2019 across all included procedures, the mean physician reimbursement after adjusting for inflation decreased by -$729.82 (-38.9%) per procedure. This varied by procedure type. Unicompartmental knee arthroplasty was the only procedure to experience an increased mean reimbursement when adjusting for inflation, increasing by $241.40 (+16.6%) per procedure from 2000 to 2019. CONCLUSION: This study demonstrates decreasing Medicare reimbursement to physicians within hip and knee arthroplasty from 2000 to 2019 when adjusting for inflation. This study is important for informing the potential development of more equitable payment models and maintaining access for arthroplasty care moving forward.

Surgical Ergonomics and Musculoskeletal Pain in Arthroplasty Surgeons.

BACKGROUND: One occupational hazard inherent to total joint replacement surgeons is procedural-related musculoskeletal pain (MSP). The purpose of this study is to identify the prevalence of work-related MSP among arthroplasty surgeons and analyze associated behaviors, attitudes, and beliefs toward surgical ergonomics. METHODS: A survey was sent to members of the American Association of Hip and Knee Surgeons. The survey included 3 main sections: demographics, symptoms by body part, and attitudes/beliefs/behaviors regarding surgical ergonomics. Pain was reported using the Numeric Rating Scale (0 = no pain, 10 = maximum pain), and well-being was assessed using the Maslach Burnout Inventory. RESULTS: In total, 586 surgeons completed the survey: 96.1% male and 3.9% female. Most surgeons (96.5%) experience procedural-related MSP. Collectively, surgeons reported an average pain score of 3.7/10 (standard deviation ±1.95). Significant levels of MSP (≥5/10) were most common in the lower back (34.2%), hands (24.8%), and the neck (21.2%). There was a positive association among higher MSP and burnout (P < .001), callousness toward others (P = .005), and decreased overall happiness (P < .001). MSP was also found to have a significant impact on surgeon behavior including the degree of irritability (P < .001), alcohol intake (P < .001), and poor sleep patterns (P < .001). CONCLUSION: The prevalence of MSP among arthroplasty surgeons is extremely high. This study demonstrates that MSP has a significant impact on career attitudes, lifestyle, and overall surgeon well-being. This study may also contribute to future work to prevent cumulative chronic ailments, disability, and lost productivity of arthroplasty surgeons through promotion of improved ergonomics and risk-reduction strategies. LEVEL OF EVIDENCE: IV.

Can a Convolutional Neural Network Classify Knee Osteoarthritis on Plain Radiographs as Accurately as Fellowship-Trained Knee Arthroplasty Surgeons?

BACKGROUND: Osteoarthritis (OA) is the leading cause of disability among adults in the United States. As the diagnosis is based on the accurate interpretation of knee radiographs, use of a convolutional neural network (CNN) to grade OA severity has the potential to significantly reduce variability. METHODS: Knee radiographs from consecutive patients presenting to a large academic arthroplasty practice were obtained retrospectively. These images were rated by 4 fellowship-trained knee arthroplasty surgeons using the International Knee Documentation Committee (IKDC) scoring system. The intraclass correlation coefficient (ICC) for surgeons alone and surgeons with a CNN that was trained using 4755 separate images were compared. RESULTS: Two hundred eighty-eight posteroanterior flexion knee radiographs (576 knees) were reviewed; 131 knees were removed due to poor quality or prior TKA. Each remaining knee was rated by 4 blinded surgeons for a total of 1780 human knee ratings. The ICC among the 4 surgeons for all possible IKDC grades was 0.703 (95% confidence interval [CI] 0.667-0.737). The ICC for the 4 surgeons and the trained CNN was 0.685 (95% CI 0.65-0.719). For IKDC D vs any other rating, the ICC of the 4 surgeons was 0.713 (95% CI 0.678-0.746), and the ICC of 4 surgeons and CNN was 0.697 (95% CI 0.663-0.73). CONCLUSIONS: A CNN can identify and classify knee OA as accurately as a fellowship-trained arthroplasty surgeon. This technology has the potential to reduce variability in the diagnosis and treatment of knee OA.

Screening for Periprosthetic Joint Infections With ESR and CRP: The Ideal Cutoffs.

BACKGROUND: The purpose of this study was to (1) determine the sensitivity and specificity of erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) when screening for a periprosthetic joint infection (PJI) using the standard MSIS cutoff of 30 mm/h and 10 mg/L, respectively, and (2) determine the optimal ESR and CRP cutoff to achieve a sensitivity ≥95%. METHODS: We retrospectively analyzed 81 PJI patients and 83 noninfected arthroplasty patients. We calculated the sensitivity and specificity (and 95% confidence intervals) for ESR and CRP at thresholds of 30 mm/h and 10 mg/L, respectively. We determined the optimal cutoff for both ESR and CRP to yield a sensitivity greater than or equal to 95%. RESULTS: The ESR cutoff that resulted in a sensitivity ≥ to 95% (95% CI: 85.2-97.6%) was 10 mm/h, and the CRP cutoff that resulted in a sensitivity ≥ to 95% (95% CI: 87.1-98.4%) was 5 mg/L. The sensitivity and specificity with a combined ESR and CRP of 10 mm/h and 5 mg/L was 100% (95% CI: 94.1-100%) and 54.7% (95% CI: 46.4-62.3%). CONCLUSION: When using ESR and CRP as a screening tool with the accepted cutoffs of 30 mm/h and 10 mg/L, there is an unacceptably low sensitivity and a high number of false negatives. Therefore, further recommendation must be given to lowering these thresholds to avoid the devastating morbidity of a missed PJI. LEVEL OF EVIDENCE: III.