Regional Differences in Reimbursement, Volume, and Patient Characteristics Exist for Rotator Cuff Repairs: A Temporal Analysis from 2013 to 2021.

BACKGROUND: Prior studies have demonstrated declining reimbursement and changing procedural utilization across multiple orthopedic subspecialties, yet a comprehensive examination of this has not been performed for rotator cuff repair, particularly at a geographic level. The purpose of this study was to evaluate changes in reimbursement, utilization, and patient populations for open and arthroscopic rotator cuff repairs (RCR) from 2013 to 2021 at a national and regional level. METHODS: The Medicare Physician and Other Practitioners database from years 2013 to 2021 were queried to extract all episodes of open chronic RCR, open acute RCR, and arthroscopic RCR. Utilization was measured as procedural volume per 10,000 Medicare beneficiaries. Inflation-adjusted reimbursement, utilization, surgeon information, and patient characteristics were extracted for each procedure for each year. Data was stratified geographically based on US Census regions and rural-urban commuting codes. Kruskal-Wallis tests and linear regressions were performed to compare geographical areas. RESULTS: Between 2013 and 2021, arthroscopic RCR utilization increased by 9.4% (11.0/10,000 to 12.0/10,000), while open chronic RCR utilization decreased by 58.8% (2.0/10,000 to 0.8/10,000). During that time, average inflation-adjusted reimbursement declined by 10.0% and 11.3% for arthroscopic and open chronic RCR, respectively. The increase in utilization and decrease in reimbursement was greatest in the Midwest. In 2021, arthroscopic RCR utilization was 12.0/10,000, while average reimbursement for was $846.87, nationally. Utilization was highest in the South (14.5/10,000) and lowest in the Northeast (8.1/10,000) (p<0.001). Alternatively, reimbursement was highest in the Northeast ($904.60) and lowest in the South ($830.80) (p<0.001). The proportion of patients who were male, Medicaid eligible, or non-White was highest in the West (p<0.001). Patients in the West also had the fewest comorbidities. Increased patient comorbidities, when controlling patient demographics, was associated with lower reimbursement nationally and within the Northeast (p<0.001). CONCLUSION: Geographical discrepancies in rotator cuff repair utilization and reimbursement exist. The South consistently demonstrates the highest utilization of RCR, while also having the lowest reimbursement. Alternatively, the Northeast has the lowest utilization but the highest reimbursement. Increased patient population comorbidities were associated with reduced RCR reimbursement for surgeons in the Northeast, but not in other regions.

Low-Income, Poor Physical Health, Poor Mental Health, and Other Social Risk Factors Are Associated With Decreased Access to Care in Patients With Carpal Tunnel Syndrome.

BACKGROUND: Carpal Tunnel Syndrome (CTS) is associated with a significant personal and societal burden. Evaluating access to care can identify barriers, limitations, and disparities in the delivery of healthcare services in this population. The purpose of this study was to evaluate access to overall healthcare and healthcare utilization among patients with CTS. METHODS: This is a retrospective cohort study conducted with the All of Us database. Patients diagnosed with CTS that completed the access to care survey were included and matched to a control group. The primary outcomes were access to care across 4 domains: (1) delayed care, (2) could not afford care, (3) skipped medications, and (4) over 1 year since seeing provider. Secondary analysis was then performed to identify patient-specific factors associated with reduced access to care. RESULTS: In total, 7649 patients with CTS were included and control matched to 7649 patients without CTS. In the CTS group, 33.7% (n = 2577) had delayed care, 30.4% (n = 2323) could not afford care, 15.4% (n = 1180) skipped medications, and 1.6% (n = 123) had not seen a provider in more than 1 year. Within the CTS cohort, low-income, worse physical health, and worse mental health were associated with poor access to care. CONCLUSION: Patients experience notable challenges with delayed care, affordability of care, and medication adherence regardless of having a diagnosis of CTS. Targeted interventions on modifiable risk factors such as low income, poor mental health, and poor physical health are important opportunities to improve access to care in this population.

Access to Care and Health Care Utilization Among Patients With Nephrolithiasis.

OBJECTIVE: To characterize the impact of nephrolithiasis diagnosis and treatment on health care utilization and identify predictors of barriers to care in the patient population. METHODS: We conducted a retrospective cohort study using the All of Us Database, a National Institutes of Health database targeting recruitment of underrepresented populations. Patients with a diagnosis of kidney stones were included and matched to a control group. Primary outcomes were patients' self-reported health care access and utilization. Univariable and multivariable regression analyses were performed. RESULTS: 9173 patients with a diagnosis of nephrolithiasis were included and matched to 9173 controls without a diagnosis of nephrolithiasis. Patients with kidney stones were less likely to have had >1 year since last provider visit (1.7% vs 3.8%, P <.001), but did not report increased delays obtaining care (31%), inability to afford care (11.4%), or higher likelihood of skipping medications (12.9%). Among patients with stones, 1208 (13.2%) had been treated surgically. On multivariable analysis, younger age, female sex, lower income, lower education, non-insured status, and lower physical and mental health were all associated with delays obtaining care, difficulty affording care, skipping medications, and/or prolonged time since seeing a provider. CONCLUSION: A diagnosis of nephrolithiasis and subsequent surgical intervention were not associated with an increase in patient-reported barriers to care. However, among patients with nephrolithiasis, younger, comorbid, female patients from lower socioeconomic status are at significant risk of being unable to access and utilize treatment.

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.

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.

Revision Arthroplasty Among Medicare Patients in the United States - Arthroplasty Surgeons are Doing More for Less.

BACKGROUND: Previously documented trends of major joint arthroplasty demonstrate increasing volume and decreasing reimbursement for primary total knee and total hip arthroplasty procedures. As such, the purpose of this study was to evaluate trends in revision knee and hip arthroplasty volume and true Medicare reimbursements to physicians. METHODS: The publicly accessible Centers for Medicare and Medicaid files were evaluated. Data were retrieved from the Part B National Summary Data File and queried for revision knee and hip arthroplasty billed to Medicare from 2000 to 2021. The total charge submitted to Medicare, Medicare reimbursement, number of revision arthroplasty surgeries performed, and average reimbursement per surgery were collected for each year. All monetary data were adjusted for inflation to 2021 dollars. RESULTS: There were 492,360 revision total knee arthroplasty surgeries and 424,163 revision hip arthroplasty procedures billed to Medicare from 2000 to 2021. Medicare was billed a total of $919,603,674.86 for revision knee and $862,979,761.57 for revision hip arthroplasty during that time. Medicare reimbursed physicians an average of $1,499.89 per knee revision and $1,603.32 per hip revision surgery. The total volume of revision knee arthroplasty increased by 9,380 (62%) and revision hip decreased by 1,743 (9%) from the year 2000 to 2021. However, there was a decrease of average reimbursement per procedure of more than 37% ($1,987.14 to 1,254) and 39% ($2,149.87 to 1,311.17), respectively. CONCLUSIONS: Despite a notable increase in the volume of revision total knee and stagnant revision hip arthroplasty, total billings to and reimbursements from Medicare for these procedures have not changed markedly per year. Importantly, this means that physicians are conducting more of these high-impact procedures yearly, while being reimbursed per procedure at a declining rate. This may indicate a need to re-assess billing and reimbursement rates for revision arthroplasty, in the context of the ever-increasing inflation rate.

Athletes Continue to Show Functional Performance Deficits at Return to Sport After Anterior Cruciate Ligament Reconstruction: A Systematic Review.

PURPOSE: To systematically review the existing literature on the functional performance of athletes at the time of return-to-sport (RTS) clearance after anterior cruciate ligament reconstruction (ACLR). METHODS: A systematic literature search of the MEDLINE, EMBASE, Scopus, and Web of Science databases was performed. The inclusion criteria were original research reports with study populations of athletes who had undergone ACLR and had undergone objective functional testing immediately after clearance to RTS. Functional testing was stratified by hop tests, strength tests, kinetic assessment, and kinematic assessment, and data were extracted from each study using a standardized template. RESULTS: Of the 937 unique studies identified, 46 met the inclusion criteria. The average time between ACLR and functional testing was 7.9 months among the included studies. In 10 of 17 studies, patients were found to have an average quadriceps strength limb symmetry index of less than 90%. However, only 2 of 12 studies found the average hop test limb symmetry index to be less than 90%. Kinematics included reduced knee flexion angle and increased trunk flexion on landing in ACLR patients compared with matched controls. On evaluation of kinetics, ACLR patients showed reduced peak vertical ground reaction force, lower peak knee extension and knee flexion moments, and altered energy absorption contribution compared with matched controls. CONCLUSIONS: This systematic review suggests that athletes show functional deficits at the time of RTS at an average of 7.9 months after ACLR. Traditional functional tests, such as strength and hop tests, are not able to accurately identify patients who continue to show deficits. The most common biomechanical deficits that persist after RTS clearance include diminished peak knee extension moment, decreased knee flexion angle, increased trunk flexion angle, reduced vertical ground reaction force, and increased hamstring central activation ratio during various functional gait and landing tasks. LEVEL OF EVIDENCE: Level III, systematic review of Level I to III studies.

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.

Outpatient Motor Retraining for Functional Movement Disorder: Predictors of a Favorable Short-Term Response.

Background: Treating functional movement disorder (FMD) with motor retraining is effective but resource intensive. Objectives: Identify patient, disease, and program variables associated with favorable treatment outcomes. Methods: Retrospective review of the 1 week intensive outpatient FMD program at Mayo Clinic in Minnesota from February 2019 to August 2021. Outcomes included patient-reported measures (Canadian Occupational Performance Measure-Performance and Satisfaction subscales [COPM-P and COPM-S, range 0-10] and Global Rating of Change [GROC, -7 to +7]) and a retrospective investigator-rated scale (0-3, worse/not improved to significantly improved/resolved). Linear regression models identified variables predicting favorable outcomes. Results: Participants (n = 201, 74% female, mean age = 46) had median FMD duration of 24 months. The commonest FMD subtypes were gait disorder (65%), tremor (41%) and weakness (17%); 53% had ≥2 subtypes. Most patients (88%) completed a therapeutic screening process before program entry. Patient-reported outcomes at the end of the week improved substantially (COPM-P average change 3.8 ± 1.9; GROC post-program average 5.5 ± 1.7). Available investigator-rated outcomes from short-term follow-up were also positive (102/122 [84%] moderately to significantly improved/resolved). Factors predicting greater improvement in COPM-P were completing therapeutic screening, higher number of non-motor symptoms, shorter FMD duration, earlier program entry, lower baseline COPM scores, and (among screened patients) higher GROC between therapeutic screening and program start. Conclusion: Patients with diverse FMD subtypes improved substantially over a 1 week period. Utilization of therapeutic screening and greater improvement between therapeutic screening and program start were novel predictors of favorable outcomes. Non-motor symptoms did not preclude positive responses, although patients with predominant non-motor burden were excluded.

Biomechanics and situational patterns associated with anterior cruciate ligament injuries in the National Basketball Association (NBA).

OBJECTIVES: Perform a comprehensive video analysis of all anterior cruciate ligament (ACL) injuries in National Basketball Association (NBA) athletes from 2006 to 2022 to determine the associated biomechanics, injury mechanism and game situation. METHODS: NBA players diagnosed with an ACL tear from 2006 to 2022 were identified and videos of each injury evaluated by two reviewers. Visual evaluation included assessment of joint kinematics at three time points: initial contact of the injured leg with the ground (IC), 33 milliseconds later (IC+33) and 66 milliseconds later (IC+66). Game situation was assessed qualitatively. RESULTS: Videos of 38 out of 47 (80.9%) ACL tears were obtained. 9 injuries were non-contact, while 29 involved indirect contact. Between IC and IC+33, average knee valgus increased from 5.1° to 12.0° and knee flexion increased from 12.6° to 32.6°. At all time points, the majority of injuries involved trunk tilt and rotation towards the injured leg, hip abduction and neutral foot rotation. The most common game situations for injury included the first step when attacking the basket following picking up the ball (n=13), landing following contact in the air (n=11) and jump stop (n=5). CONCLUSION: Three major mechanisms predominate ACL tears in NBA players: the first step following picking up the ball when attacking, landing and jump stops. None of the injuries reviewed demonstrated direct contact to the knee, emphasising the importance of body kinematics in this injury pattern. The increase in knee valgus and knee flexion between IC and IC+33 should be noted as a possible precipitant to injury.

Bibliometric Analysis of the Top 50 Most Influential Studies on Patellar Tendon Injury.

Background: There is a wide range of literature on patellar tendon injury, making it increasingly difficult to stay informed on the most influential studies in this field. It is essential to be familiar with the foundational articles of patellar tendon injury research to understand the current state of the literature and deliver high quality care. Purpose: To objectively identify the 50 most influential articles relating to patellar tendon injury and conduct a bibliometric analysis to identify key features of these articles. Study Design: Cross-sectional study. Methods: The Clarivate Analytics Web of Knowledge database was utilized to gather metrics on the 50 most cited articles on patellar tendon injury on June 27, 2022. The information extracted from each article included publication year, number of citations, author information, article type, level of evidence, country of origin, journal name, study focus, and industry influence. Results: The top 50 studies were cited a total of 8543 times and published between 1977 and 2015. The majority of articles were published after 2003, and the majority of citations were accrued after 2011. The most prevalent article types were cohort studies (n = 23), and the majority of studies were of evidence level 2 (n = 14) or 4 (n = 13). Australia and the United States (US) each published the most studies (n = 11). Only 4 (8%) studies focused on patellar tendon rupture, and 12 (24%) of the top 50 studies were associated with industry. Conclusion: The majority of the top 50 most influential articles in patellar tendon injury were published and accumulated citations in the past 10 to 20 years. Non-US countries, institutions, and journals published many of the top 50 studies, reflecting a global interest and commitment to research in this field. Patellar tendon rupture and surgical repair represents a minority of research in the top 50 studies and could be a point of growth in the future.

A Bibliometric Analysis of the Top 100 Most Influential Studies on Robotic Arthroplasty.

Background: The use of robotics in arthroplasty surgery has increased substantially in recent years. The purpose of this study was to objectively identify the 100 most influential studies in the robotic arthroplasty literature and to conduct a bibliometric analysis of these studies to describe their key characteristics. Methods: The Clarivate Analytics Web of Knowledge database was used to gather data and metrics for robotic arthroplasty research using Boolean queries. The search list was sorted in descending order by the number of citations, and articles were included or excluded based on clinical relevance to robotic arthroplasty. Results: The top 100 studies were cited a total of 5770 times from 1997 to 2021, with rapid growth in both citation generation and the number of articles published occurring in the past 5 years. The top 100 robotic arthroplasty articles originated from 12 countries, with the United States being responsible for almost half of the top 100. The most common study types were comparative studies (36) followed by case series (20), and the most common levels of evidence were III (23) and IV (33). Conclusions: Research on robotic arthroplasty is rapidly growing and originates from a wide variety of countries, academic institutions, and with significant industry influence. This article serves as a reference to direct orthopaedic practitioners to the 100 most influential studies in robotic arthroplasty. We hope that these 100 studies and the analysis we provide aid healthcare professionals in efficiently assessing consensus, trends, and needs within the field.

Neural dynamics underlying associative learning in the dorsal and ventral hippocampus.

Animals associate cues with outcomes and update these associations as new information is presented. This requires the hippocampus, yet how hippocampal neurons track changes in cue-outcome associations remains unclear. Using two-photon calcium imaging, we tracked the same dCA1 and vCA1 neurons across days to determine how responses evolve across phases of odor-outcome learning. Initially, odors elicited robust responses in dCA1, whereas, in vCA1, odor responses primarily emerged after learning and embedded information about the paired outcome. Population activity in both regions rapidly reorganized with learning and then stabilized, storing learned odor representations for days, even after extinction or pairing with a different outcome. Additionally, we found stable, robust signals across CA1 when mice anticipated outcomes under behavioral control but not when mice anticipated an inescapable aversive outcome. These results show how the hippocampus encodes, stores and updates learned associations and illuminates the unique contributions of dorsal and ventral hippocampus.