Is the Rise of Medicare Advantage Impacting the Fidelity of Traditional Medicare Claims Data? Implications for Reporting of Long-Term Total Hip Arthroplasty Survivorship.

BACKGROUND: Arthroplasty registries often use traditional Medicare (TM) claims data to report long-term total hip arthroplasty (THA) survivorship. The purpose of this study was to determine whether the large number of patients leaving TM for Medicare Advantage (MA) has compromised the fidelity of TM data. METHODS: We identified 10,962 THAs in 9,333 Medicare-eligible patients who underwent primary THA from 2000 to 2020 at a single institution. Insurance type was analyzed, and 83% of patients had TM at the time of THA. Survivorship free from any revision or reoperation was calculated for patients who have TM. The same survivorship end points were recalculated with censoring performed when a patient transitioned to an MA plan after their primary THA to model the impact of losing patients from the TM dataset. Differences in survivorship were compared. The mean follow-up was 7 years. RESULTS: From 2000 to 2020, there was a decrease in TM insurance (93 to 73%) and a corresponding increase in MA insurance (0 to 19%) among THA patients. Following THA, 23% of TM patients switched to MA. For patients who had TM at the time of surgery, 15-year survivorship free from any reoperation or revision was 90% and 93%, respectively. When censoring patients upon transition from TM to MA, survivorship free from any reoperation became significantly higher (92 versus 90% at 15 years; hazard ratio = 1.16, P = .033), and there was a trend toward higher survivorship free from any revision (95 versus 93% at 15 years; hazard ratio = 1.16, P = .074). CONCLUSIONS: Approximately 1 in 4 patients left TM for MA after primary THA, effectively making them lost to follow-up within TM datasets. The mass exodus of patients out of TM appears to have led to a slight overestimation of survivorship free from any reoperation and trended toward overestimating survivorship free from any revision. If MA continues to grow, efforts to obtain MA data will become even more important.

The Rise of Medicare Advantage: Effects on Total Joint Arthroplasty Patient Care and Research.

BACKGROUND: Medicare Advantage (MA) plans are popular among Medicare-eligible patients, but little is known about MA in lower-extremity total joint arthroplasty (TJA). The purpose of this study was to describe trends in MA utilization and analyze differences in patient characteristics and postoperative outcomes between patients undergoing primary TJA using traditional Medicare (TM) or MA plans. METHODS: Patients ≥65 years of age who underwent primary total knee or total hip arthroplasty were identified using the Premier Healthcare Database. Patients were categorized into TM and MA cohorts. Data from 2004 to 2020 were used to describe trends in insurance coverage. Data from 2015 to 2020 were used to identify differences in patient characteristics and postoperative complications using ICD-10 codes. Multivariate analyses were performed using 2015 to 2020 data to account for potential confounders. RESULTS: From 2004 to 2020, the proportion of patients with MA increased from 7.9% to 34.4%, while those with TM decreased from 83.7% to 54.0%. Of the 697,317 patients who underwent primary elective TJA from 2015 to 2020, 471,439 (67.6%) had TM coverage and 225,878 (32.4%) had MA coverage. The cohorts were similar in terms of age and sex. However, a higher proportion of Black patients (8.29% compared with 4.62%; p < 0.001) and a lower proportion of White patients (84.0% compared with 89.2%; p < 0.001) were enrolled in MA compared with TM. After controlling for confounders, patients with MA had higher odds of surgical site infection (adjusted odds ratio [aOR]: 1.15; 95% confidence interval [CI]: 1.04 to 1.47; p = 0.031), periprosthetic joint infection (aOR: 1.10; 95% CI: 1.03 to 1.18; p = 0.006), stroke (aOR: 1.15; 95% CI: 1.02 to 1.31; p = 0.026), and acute kidney injury (aOR: 1.08; 95% CI: 1.04 to 1.11; p < 0.001), but lower odds of urinary tract infection (aOR: 0.94; 95% CI: 0.90 to 0.98; p = 0.003). CONCLUSIONS: From 2004 to 2020, the number of patients utilizing MA increased markedly such that 1 in 3 were covered by MA in 2020. From 2015 to 2020, patients who were non-White were more likely to have MA than TM, and the MA group had a higher rate of several postoperative complications compared with the TM group. As TM claims data inform health-care policy and clinical decisions, this change portends future challenges, including limitations in arthroplasty registry research, an increase in the administrative burden of surgeons, and a potential worsening of social disparities in health care.

Analysis of New Orthopaedic Technologies in Large Database Research.

ABSTRACT: Improvements in orthopaedic surgery go hand in hand with technological advances. The present article outlines the historical and current uses of large databases and registries for the evaluation of new orthopaedic technologies, providing insights for future utilization, with robotic-assisted surgery as the example technology.

Who Is Still Receiving Blood Transfusions After Primary and Revision Total Joint Arthroplasty?

BACKGROUND: Incidence of blood transfusions after primary and revision total hip and knee arthroplasty (primary total hip arthroplasty [pTHA], revision THA [rTHA], primary total knee arthroplasty [pTKA], and revision TKA [rTKA]) has been decreasing for a multitude of reasons. The purpose of this study was to assess whether transfusion rates have continued to decline and evaluate patient factors associated with transfusions. METHODS: The American College of Surgeons National Surgical Quality Improvement Program was queried to identify patients undergoing pTHA, pTKA, rTHA, and rTKA between 2011 and 2019. Patients undergoing bilateral procedures and arthroplasty for fracture, infection, or tumor were excluded. Trends in blood transfusions were assessed. Patient factor association with blood transfusions was evaluated using 2018 and 2019 data. RESULTS: Transfusion rates decreased from 21.4% in 2011 to 2.5% in 2019 for pTHA (P < .0001). For pTKA, transfusion rates declined from 17.6% to 0.7% (P < .0001). In rTHA, the transfusion rate decreased from 33.5% to 12.0% from 2011 to 2019 (P < .0001). Transfusion rates declined from 19.4% to 2.6% for rTKA during the study period (P < .0001). Transfusions were more frequent in patients who were older, female, with more comorbidities, with lower hematocrit, receiving nonspinal anesthesia, and with longer operative time. Lower preoperative hematocrit, history of bleeding disorders, and preoperative transfusion were associated with greater odds for postoperative transfusion after multivariate analysis. CONCLUSION: Transfusions after both primary and revision total joint arthroplasty have continued to decrease. Studies of arthroplasty complications should account for decreasing transfusions when assessing overall complication rates. Future studies should consider interventions to further reduce transfusions in revision arthroplasty.

Longer Length of Stay Is Associated With More Early Complications After Total Knee Arthroplasty.

Background: Length of stay (LOS) following total knee arthroplasty (TKA) has decreased over recently years. In 2018, the Centers for Medicare and Medicaid Services removed TKA from Inpatient-Only List (IPO), incentivizing further expansion of outpatient TKA. However, many patients may still require postsurgical hospitalization. The purpose of this study was to assess early outcomes for TKA based on length of stay (LOS). Methods: We identified patients undergoing elective, primary TKA in the National Surgical Quality Improvement Program database using CPT code 27447 between 2015 and 2018. Patients were stratified by length of stay (LOS) 0 days, 1-2 days, and ≥3 days. Thirty-day rates of any complication, wound complications, readmission, and reoperation were assessed. Multivariate analysis was performed to adjust for confounding variables. Results: 5,655 (3%) patients underwent outpatient TKA, 130,543 (59%) had LOS 1-2 days, and 84,986 (38%) had LOS ≥3 days. Any complication was experienced in 4.1% of those with LOS 0 days, 4.3% for those with LOS of 1-2 days, and 10.5% for patients with LOS ≥3 days (p<0.0001). Readmission occurred in 2.2%, 2.6%, and 4.0% for the 3 groups, respectively (p<0.0001). After multivariate analysis, there was no significant difference in any outcome measure between patients with LOS 0 and 1-2 days, however those with LOS ≥3 days had higher odds of complications, reoperation, and readmission. Conclusion: A significant number of patients had LOS ≥3 days following TKA and had more comorbidities and complications. Outpatient TKA was not associated with increased early complication compared to those with LOS of 1-2 days. Despite expansion of outpatient surgery, postsurgical hospitalization remains an integral part of care following TKA. Level of Evidence: III.

Are surgeons still performing primary total knee arthroplasty in the morbidly obese?

AIMS: The purpose of this study was to assess total knee arthroplasty (TKA) volume and rates of early complications in morbidly obese patients over the last decade, where the introduction of quality models influencing perioperative care pathways occurred. METHODS: Patients undergoing TKA between 2011 to 2018 were identified in the American College of Surgeons National Surgical Quality Improvement Program database. Patients were stratified by BMI < 40 kg/m2 and ≥ 40 kg/m2 and evaluated by the number of cases per year. The 30-day rates of any complication, wound complications, readmissions, and reoperation were assessed. Trends in these endpoints over the study period were compared between groups using odds ratios (ORs) and multivariate analyses. RESULTS: In total, 314,695 patients underwent TKA and 46,362 (15%) had BMI ≥ 40 kg/m2. The prevalence of morbid obesity among TKA patients did not change greatly, ranging between 14% and 16%. Reoperation rate decreased from 1.16% to 0.96% (odds ratio (OR) 0.81 (95% confidence interval (CI) 0.66 to 0.99)) for patients with BMI < 40 kg/m2, as did rates of readmission (4.46% to 2.87%; OR 0.61 (0.55 to 0.69)). Patients with BMI ≥ 40 kg/m2 also had fewer readmissions over the study period (4.87% to 3.34%; OR 0.64 (0.49 to 0.83)); however, the rate of reoperation did not change (1.37% to 1.41%; OR 0.99 (0.62 to 1.56)). Significant improvements were not observed for infective complications over time for either group; patients with BMI ≥ 40 kg/m2 had increased risk of both deep infection and wound complications compared to non-morbidly obese patients. Rate of any complication decreased for all patients. CONCLUSION: The proportion of TKAs in morbidly obese patients has not significantly changed over the past decade. Although readmission rates improved for all patients, reductions in reoperation in non-morbidly obese patients were not experienced by the morbidly obese, resulting in a widening of the complication gap between these cohorts. Care improvements have not lowered the differential risk of infective complications in the morbidly obese. Cite this article: Bone Joint J 2021;103-B(6 Supple A):38-44.

Has Removal From the Inpatient-Only List Increased Complications After Outpatient Total Knee Arthroplasty?

BACKGROUND: On 1/1/2018, the Centers for Medicare and Medicaid Services removed total knee arthroplasty (TKA) from the Inpatient-Only (IPO) list. This change allowed expansion of outpatient TKA, potentially to include older, more frail patients at greater risk for perioperative complications. The purpose of this study was to evaluate the impact of removing TKA from the IPO list on early complications. METHODS: Patients undergoing TKA in the National Surgical Quality Improvement Program database were identified using CPT code 27447. Only cases with length of stay of zero days were included. Rates of 30-day complications, readmissions, and reoperation were compared before and after TKA was removed from the IPO list (2015-2017 vs 2018). The analysis was performed both with and without propensity score matching. RESULTS: 212,313 patients underwent TKA during the study period. 2466 (1.5%) were outpatient TKA in 2015-2017 and 3189 (5.6%) in 2018. After propensity matching, there were 2458 patients in each cohort. Rates of total 30-day complications were significantly lower in 2018 (3.7%) than the years TKA remained on the IPO (4.5%, P = .04). Similarly, rates of any reoperation decreased from 1.2% during 2015-2017 to 0.6% in 2018 (P = .03). There were no significant changes in rates of readmission (2.5% vs 2.2%, P = .5) or wound complications (0.8% vs 0.8%, P = 1.0). CONCLUSION: Removal of TKA from the IPO list did not result in an increase in complications or readmissions. These data suggest, despite the regulatory change, surgeons have continued to exercise sound judgment as to what patients can safely undergo outpatient TKA.

TKR after posttraumatic and primary knee osteoarthritis: a comparative study.

BACKGROUND: A few literatures reported that the outcomes of total knee replacement (TKR) in posttraumatic osteoarthritis (PTOA) were lower compared to TKR in primary osteoarthritis (primary OA). The study's purpose was to compare the comorbidity and outcome of TKR among fracture PTOA, ligamentous PTOA, and primary OA. The secondary aim was to identify the effect of postoperatively lower limb mechanical axis on an 8-year survivorship after TKR between PTOA and primary OA. METHODS: Seven hundred sixteen patients with primary OA, 32 patients with PTOA (knee fracture subgroup), and 104 PTOA (knee ligamentous injury subgroup) were recruited. Demography, comorbidities, Charlson Comorbidity Index (CCI), operative parameters, mechanical axis, functional outcome assessed by WOMAC, and complications were compared among the three groups. RESULTS: PTOA group was significantly younger (p<0.0001) with a higher proportion of men (p=0.001) while the primary OA group had higher comorbidities than the PTOA group, including anticoagulant usage (p=0.0002), ASA class ≥3 (p<0.0001), number of diseases ≥ 4 (p<0.0001), and CCI (p<0.0001). Both the fracture PTOA group (p<0.0001) and ligamentous PTOA group (p = 0.009) had a significantly longer operative time than the primary OA group. The fracture PTOA group had significantly lower pain components and stiffness components than the primary OA group. There was no significant difference in the rate of an aligned group, outlier group, and an 8-year survivorship in both groups. CONCLUSION: The outcome following TKR in the fracture PTOA was poorer compared to primary knee OA in the midterm follow-up. However, no difference was detected between the ligamentous PTOA and primary knee OA. The mechanical axis alignment within the neutral axis did not affect the 8-year survivorship after TKR in both groups. LEVEL OF EVIDENCE: Level III; retrospective cohort study.

The Impact of Transitioning From International Classification of Diseases, Ninth Revision to International Classification of Diseases, Tenth Revision on Reported Complication Rates Following Primary Total Knee Arthroplasty.

BACKGROUND: In 2015, the healthcare system transitioned from International Classification of Diseases, Ninth Revision (ICD-9) coding to the Tenth Revision (ICD-10). We sought to determine the effect of this change on the reported incidence of complications following total knee arthroplasty (TKA). METHODS: The Humana administrative claims database was queried from 2 years prior to October 1, 2015 (ICD-9 cohort) and for 1 year after this date (ICD-10 cohort) to identify all TKA procedures. Complications occurring within 6 months of surgery were captured using the respective coding systems. Incidence of each complication was compared between cohorts using risk ratios (RR) and 95% confidence intervals. RESULTS: There were 19,009 TKAs in the ICD-10 cohort and 38,172 TKAs in the ICD-9 cohort. The incidence of each complication analyzed was significantly higher in the ICD-9 cohort relative to the ICD-10 cohort. Periprosthetic joint infection occurred in 1.9% vs 1.3% (RR 1.5, 1.3-1.9), loosening in 0.3% vs 0.1% (RR 2.7, 1.8-4.9), periprosthetic fracture in 0.3% vs 0.1% (RR 3.0, 1.6-4.5), and other mechanical complications in 0.7% vs 0.4% (RR 2.0, 1.5-2.5) (P < .05 for all). CONCLUSION: The transition from ICD-9 to ICD-10 coding has altered the reported incidence of complications following TKA. These results are likely due to the added complexity of ICD-10 which is joint and laterality specific. It is important to understand the differences between coding systems as this data is used for quality initiatives, risk adjustment models, and clinical research. Thoughtful methodology will be necessary when ICD-9 and ICD-10 data are being analyzed simultaneously.

More Patients Are Being Discharged Home After Total Knee Arthroplasty, However Rates Vary Between Large Databases.

BACKGROUND: There have been significant advancements in perioperative care for total knee arthroplasty (TKA). It is essential to quantify the impact of efforts to better optimize patients and deliver care. The purpose of this study is to assess trends in discharge destination, length of stay (LOS), and complications. METHODS: Patients undergoing primary TKA were identified in the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) and Humana claims databases using procedural codes. Patients were classified as being discharged home or not home (skilled nursing facility, acute rehab, other non-home destinations). Changes in discharge destination, LOS, comorbidity burden, readmissions, and reoperation were assessed. RESULTS: In total, 254,195 ACS NSQIP patients underwent TKA, with an increase in home discharge from 67.2% in 2011 to 85.3% in 2017 (P < .0001). There were 178,071 TKA patients in the Humana database and home discharge increased from 62.1% in 2007 to 74.7% in 2016 (P < .0001). LOS decreased and proportion of patients with an American Society of Anesthesiologists score ≥3 or Charlson Comorbidity Index ≥2 increased significantly for both home and non-home going patients. Home going patients had a decrease in 30-day readmissions (ACS NSQIP: 2011: 3.6%, 2017: 2.7%, P = .001; Humana: 2007: 4.0%, 2016: 2.4%, P < .0001). CONCLUSION: Patients undergoing TKA were discharged home more often, had shorter LOS, and had significantly lower readmission rates, despite an increasingly comorbid patient population. It is likely that these improvements in postoperative care have resulted in significant cost savings, for both payers and hospitals. The efforts necessary to create and maintain such improvements, as well as the source of data, should be considered when changes to reimbursement are being evaluated. The metrics studied in this paper should provide a comparison for further improvement with continued transition to bundle payments and transition to outpatient surgery with removal of TKA from the inpatient-only list.

Predictors for readmission following primary total hip and total knee arthroplasty.

BACKGROUND: Readmission following total joint arthroplasty has become a closely watched metric for many hospitals in the United States due to financial penalties imposed by Centers for Medicare and Medicaid Services. The purpose of this study was to identify both preoperative and postoperative reasons for readmission within 30 days following primary total hip and total knee arthroplasty (TKA). METHODS: Retrospective data were collected for patients who underwent elective primary total hip arthroplasty (THA; CPT code 27130) and TKA (27447) from 2008 to 2013 at our institution. The sample was separated into readmitted and nonreadmitted cohorts. Demography, comorbidities, Charlson comorbidity index (CCI), operative parameters, readmission rates, and causes of readmission were compared between the groups using univariate and multivariate regression analysis. RESULTS: There were 42 (3.4%) and 28 (2.2%) readmissions within 30 days for THA and TKA, respectively. The most common cause of readmission within 30 days following total joint arthroplasty was infection. Trauma was the second most common reason for readmission of a THA while wound dehiscence was the second most common cause for readmission following TKA. With univariate regression, there were multiple associated factors for readmission among THA and TKA patients, including body mass index, metabolic equivalent (MET), and CCI. Multivariate regression revealed that hospital length of stay was significantly associated with 30-day readmission after THA and TKA. CONCLUSION: Patient comorbidities and preoperative functional capacity significantly affect 30-day readmission rate following total joint arthroplasty. Adjustments for these parameters should be considered and we recommend the use of CCI and METs in risk adjustment models that use 30-day readmission as a marker for quality of patient care. LEVEL OF EVIDENCE: Level III/Retrospective cohort study.

Salvage of Distal Femoral Replacement Loosening with Massive Osteolysis Using Impaction Grafting: A Report of 2 Cases.

CASE: Salvage of 2 cases of distal femoral replacement loosening with massive osteolysis using impaction grafting are presented with 9- and 11-year follow-ups. CONCLUSION: Surgeons should keep impaction grafting in their armamentarium for cases of failed DFR with severe osteolysis. Doing so may allow for preservation of the native hip and deferment of more radical procedures (i.e. total femur replacement) that have high rates of complication and poor survivorship.

The Inaccuracy of ICD-10 Coding in Revision Total Hip Arthroplasty and Its Implication on Revision Data.

BACKGROUND: The International Statistical Classification of Diseases, 10th Revision (ICD-10), was adopted by the United States on October 1, 2015 and expanded coding from 3800 codes with the International Statistical Classification of Diseases, Ninth Revision, procedure code system (ICD-9-PCS) to 73,000. The increase in number of codes was designed to create more accurate representations of procedures like revision total hip arthroplasties (rTHAs). However, many worry that the increased complexity leads to more inaccurate coding. The purpose of this study is to determine the accuracy of ICD-10-PCS coding for rTHA and discuss the implications on registry data. METHODS: The rTHA databases at 2 large, academic medical centers were retrospectively reviewed for all rTHAs between October 1, 2015 and July 3, 2019. The laterality and specific revised components were recorded and compared with the ICD-10-PCS codes used for each procedure. The accuracy of ICD-10-PCS codes relative to the surgical record was determined using coding guidelines published by the American Joint Replacement Registry (AJRR). RESULTS: Overall, 895 cases were reviewed. Replacement coding was 22% accurate (195 of 895). For removal and replacement coding, accuracy dropped to 17% (152 of 895). All procedures had at least 1 rTHA trigger code that would signify correctly to AJRR that an rTHA occurred. CONCLUSION: In this study, the percent of correctly coded rTHA was low. All rTHA procedures had at least 1 AJRR trigger code; therefore, an rTHA would have been appropriately captured by AJRR. But these inaccuracies should make one pause when using ICD-10-PCS procedural data to try to evaluate specific rTHA details from administrative claims databases and ward against expanding ICD-10-PCS as a means to collect implant survival and registry data.

Two-Stage Exchange Arthroplasty for Periprosthetic Joint Infection Following Total Hip or Knee Arthroplasty Is Associated With High Attrition Rate and Mortality.

BACKGROUND: We sought to determine the ultimate fate of patients undergoing resection arthroplasty as a first stage in the process of 2-stage exchange and evaluate risk factors for modes of failure. METHODS: A retrospective case study was performed including all patients with minimum 2-year follow-up who underwent first-stage resection of a hip or knee periprosthetic joint infection from 2008 to 2015. Patient demographics, laboratory, and health status variables were collected. The primary outcome analyzed was defined as failure to achieve an infection-free 2-stage revision. Univariate pairwise comparison followed by multivariate regression analysis was used to determine risk factors for failure outcomes. RESULTS: Eighty-nine patients underwent resection arthroplasty in a planned 2-stage exchange protocol (27 hips, 62 knees). Mean age was 64 years (range, 43-84), 56.2% were males, and mean follow-up was 56.3 months. Also, 68.5% (61/89) of patients underwent second-stage revision. Of the 61 patients who complete a 2-stage protocol, 14.8% (9/61) of patients failed with diagnosis of repeat or recurrent infection. Mortality rate was 23.6%. Multivariate analysis identified risk factors for failure to achieve an infection-free 2-stage revision as polymicrobial infection (P < .004; adjusted odds ratio [AOR], 7.8; 95% confidence interval [CI], 2.1-29.0), McPherson extremity grade 3 (P < .024; AOR, 4.1; 95% CI, 1.2-14.3), and history of prior resection (P < .013; AOR, 4.7; 95% CI, 1.4-16.4). CONCLUSION: Patients undergoing resection arthroplasty for periprosthetic joint infection are at high risk of death (24%) and failure to complete the 2-stage protocol (32%). Those who complete the 2-stage protocol have a 15% rate of reinfection at 4.5-year follow-up.

Total Joint Arthroplasty in the Morbidly Obese: How Body Mass Index ≥40 Influences Patient Retention, Treatment Decisions, and Treatment Outcomes.

BACKGROUND: The United States is in an obesity epidemic. Obesity has multiple common comorbid conditions, including lower extremity arthritis. We sought to examine the course of treatment for a population with body mass index (BMI) ≥40 kg/m2 and osteoarthritis (OA) of the hip or knee. We investigated decision criteria that influenced arthroplasty surgeons to recommend nonoperative management vs total joint arthroplasty (TJA). For those patients who ultimately received TJA, we compared outcomes in this population to those with BMI <40 kg/m2. METHODS: This study retrospectively reviewed 158 new patients with BMI ≥40 kg/m2 and moderate/severe OA of the hip or knee. Demographics, comorbidity profiles, and weight loss were compared between groups that underwent TJA and those that did not. The arthroplasty database was used to identify patients who underwent TJA during 2016-2018 (N = 1473). Comorbidities, readmissions, surgical site infections, and overall complications were compared between those with BMI ≥40 kg/m2 and BMI <40 kg/m2. RESULTS: About 51.3% of new patients with BMI ≥40 kg/m2 and moderate/severe OA did not return for a second clinic visit. Of those who did return, 42.9% eventually underwent surgery. BMI was higher in single visit patients vs those with multiple visits (49.5 vs 46.3 kg/m2, P < .001), no difference in those scheduled on an "as-needed" basis vs a specific return date (P = .18), and did not change significantly during the 2-year follow-up (P = .41). Patients who underwent TJA had a lower mean BMI at presentation than their nonoperative counterparts (44.5 vs 47.6 kg/m2, P < .01) and demonstrated significant weight loss prior to surgery (44.5 vs 42.6 kg/m2, P < .05). When comparing patients with BMI ≥40 kg/m2 vs BMI <40 kg/m2, overall complications were not higher in the BMI ≥40 kg/m2 group, although surgical site infections were higher in those undergoing total hip arthroplasty with BMI ≥40 kg/m2 (0.3% vs 3.1%, P < .05). CONCLUSION: A majority of patients with BMI ≥40 kg/m2 and moderate/advanced OA will be lost to orthopedic follow-up. A relatively lower BMI indicates a greater chance of retention in care, and ultimately surgery, but does not influence surgeons' recommendations to continue orthopedic management. Patients who persist in seeking treatment, lose significant weight, and exhaust nonoperative alternatives may be suitable for TJA despite a BMI ≥40 kg/m2, with an overall complication rate of 4.3%. However, only 9% of patients at 2-year follow-up achieved BMI <40 kg/m2 and only 20% of surgeries were performed on patients who had achieved this proposed cutoff.

Outcomes of Hip Arthroscopy in the Medicare Patient: A Growing Population.

Background: Although the results of hip arthroscopy in the elderly have been inferior to the results in younger patients, there have recently been some encouraging reports in carefully selected series of older patients. The purpose of this study was to identify the utilization of hip arthroscopy in the Medicare population and to determine the rate and timing of revision arthroscopy and/or total hip arthroplasty (THA) with the goal of identifying risk factors for secondary procedures based on patient demographics, comorbidities and the diagnosis at the time of arthroscopy. Methods: The Medicare Standard Analytic Files were reviewed from 2005-2014 for all patients undergoing hip arthroscopy allowing for minimum 2 year follow-up (100% sample). Patients were tracked through the dataset for the occurrence of an ipsilateral THA or revision hip arthroscopy. Rates and timing of the subsequent procedures were then determined within 6 month intervals. Patients less than 65 years old were excluded. Multivariate logistic regression analysis was performed to determine the impact of patient age, sex, obesity or a diagnosis of hip osteoarthritis on need for revision procedures. Results: 3,320 Medicare patients had a hip arthroscopy during 2005-2014 (0.3% compared to THA). 73 patients (2.2%) underwent reoperation during the follow-up period. Two-thirds (n = 46) of all revision procedures occurred within one year of primary hip arthroscopy. A pre-operative diagnosis of hip osteoarthritis significantly increased the odds of reoperation (OR = 5.3). (Conclusion: Relatively few numbers of Medicare patients underwent hip arthroscopy during the time interval evaluated (0.3% when compared to THA utilization). 2.2% underwent a subsequent revision arthroscopy or THA with many occurring soon after the procedure and for the diagnosis of hip OA demonstrating the need to better define indications in this population. This study should provide baseline utilization and outcome trends for future studies.Level of Evidence: IV.

Rates and Risk Factors for Revision Hip Arthroscopy.

Background: Revision hip arthroscopy often serves as a measure for a failed primary hip arthroscopy procedure. The purpose of this study was to examine the rate, timing, and risk factors for revision hip arthroscopy using a large national database. Methods: The Humana administrative claims dataset was reviewed from 2007 through the second quarter of 2015 to identify patients undergoing hip arthroscopy using Current Procedural Terminology (CPT) codes and laterality modifiers. Patients with subsequent ipsilateral revision hip arthroscopy were identified and the rate and timing of these revisions determined. Subgroup analysis was performed to determine effects of gender, age, body mass index (BMI), osteoarthritis diagnosis, and specific hip arthroscopy procedure on revision rates. Results: There were 1807 hip arthroscopy procedures identified with a revision rate of 4% (total of 72 procedures). Of the revision procedures, 43% occurred within 6 months after the index procedure, and 86% occurred within 18 months. Age < 50 years was the only significant predictor of revision hip arthroscopy (OR 2.03, CI 1.173.53) with an even distribution across younger age groups. An osteoarthritis diagnosis, gender, and BMI did not represent significant risk factors for revision (OR 0.87, 0.98, 0.9 and CI 0.5-1.51, CI 0.6-1.59, CI 0.37-2.12, respectively). Chondroplasty was the most common procedure leading to revision (46%) followed by labral repair (37%). The most common revision procedures were chondroplasty (44%) followed by femoroplasty (38%). Conclusions: Overall, 4% of hip arthroscopy procedures underwent revision arthroscopy over the 8-year period. Revision was associated with age < 50, and revisions were most frequently performed for femoroacetabular impingement. The majority of revisions occurred within 18 months after the index procedure.Level of Evidence: IV.

Artificial Intelligence and Machine Learning in Lower Extremity Arthroplasty: A Review.

BACKGROUND: Driven by the rapid development of big data and processing power, artificial intelligence and machine learning (ML) applications are poised to expand orthopedic surgery frontiers. Lower extremity arthroplasty is uniquely positioned to most dramatically benefit from ML applications given its central role in alternative payment models and the value equation. METHODS: In this report, we discuss the origins and model specifics behind machine learning, consider its progression into healthcare, and present some of its most recent advances and applications in arthroplasty. RESULTS: A narrative review of artificial intelligence and ML developments is summarized with specific applications to lower extremity arthroplasty, with specific lessons learned from osteoarthritis gait models, joint-specific imaging analysis, and value-based payment models. CONCLUSION: The advancement and employment of ML provides an opportunity to provide data-driven, high performance medicine that can rapidly improve the science, economics, and delivery of lower extremity arthroplasty.