Faculty Bibliography

As soon as it became clear that our economy was going to be paralyzed by the SARS-CoV-2 pandemic, the American Association of Hip and Knee Surgeons leadership acted swiftly to ensure that our members were going to be eligible for the anticipated federal economic stimulus. The cessation of elective surgery, enacted in mid-March and necessary to stop the spread of the SARS-CoV-2 virus, would surely challenge the solvency of many of our members' practices. Although our advocacy efforts discussed further have helped, clearly more relief is needed. Fortunately, our mitigation efforts have led to a "flattening of the curve" and discussions have begun on when, where, and how to safely start elective surgery again.

BACKGROUND:In November 2017, CMS finalized the 2018 Medicare Outpatient Prospective Payment System rule that removed TKA from the Medicare inpatient-only (IPO) list. This action had significant and unexpected consequences. METHODS:We looked at 3 levels of the IPO rule impact on TKA for Medicare beneficiaries: a national comparison of FFS inpatient and outpatient classification for 2017 vs 2018; a survey of AAHKS surgeons completed in April 2019; and an in-depth analysis of a large academic medical center experience. An analysis of change in admission classification of patients with TKA over time, number of QIO audits, compliance solutions for the new rule, and cost implications of those compliance solutions were evaluated. RESULTS:Hospital reimbursement averages $10,122 in an outpatient facility but does not include the physician payment. Average hospital reimbursement in the inpatient setting is $11,760. The difference in hospital reimbursement varies widely (90th percentile decrease, $6725 vs 10th percentile $2048). Physician payments are the same in both settings (avg $1403). Patients with TKA not designated for inpatient admissions are not eligible for bundle payment programs. Patients designated as outpatients are subjected to higher out-of-pocket expenses. Patients may have an annual Medicare Part B Deductible ($185) and a 20% copay as well as prescription and durable medical equipment costs. An AAHKS survey demonstrated that 45.08% were with inpatient designation only, 17.62% were with outpatient designation only, 25.39% were designated as necessary, and 10.1% were designated by the hospital. This survey showed that 66 of 374 (17.65%) patients had undergone a QIO audit as a result of issues with the IPO rule. An evaluation of an AMC demonstrated that since January 1, 2018, 470 of 690 (68.1%) of CMS patients with TKA left in less than 2 midnights. The institution was subjected to 2 QIO audits. CONCLUSIONS:There are many unintended consequences to the IPO rule application to TKA.

BACKGROUND:The Centers for Medicare and Medicaid Services removed total knee arthroplasties (TKAs) from the inpatient-only (IPO) list on January 1, 2018, which meant that TKAs could be performed on a hospital outpatient basis. We examined the following: (1) the national rate of adoption of outpatient TKAs over time, (2) how adoption varied across hospitals, and (3) whether adoption of outpatient TKAs has positively or negatively impacted 90-day TKA readmission rates. METHODS:We used national patient-level Medicare Fee-for-Service Part A claims data (100% sample) from January 2017 through June 2019 to look at the quarterly trend in percent of TKAs performed as outpatient, and the distribution in this percentage across hospitals in the country. We ran a case-level regression to understand whether inpatient vs outpatient coding status relates to 90-day readmission rates. RESULTS:In 2017 prior to the removal of TKAs from the IPO list, 0.2% were performed as outpatient. In the first quarter (Q1 2018) after the rule change, 24.9% were performed as outpatient, and by the second quarter of 2019, 36.4% were performed as outpatient. These rates varied widely across hospitals from 0% (10th and 25th percentiles) to 78% (90th percentile) from January 2018 through March 2019. There was no difference in readmission rates for same-day discharges, but outpatient cases discharged after one or more nights in the hospital had statistically lower readmissions than inpatient cases. CONCLUSION/CONCLUSIONS:There was a rapid increase in the adoption of hospital outpatient TKAs following their removal from the Medicare IPO, which has resulted in lower readmission rates, and so adoption is likely to continue.

BACKGROUND:Centers for Medicare and Medicaid Services removed total knee arthroplasties (TKAs) from the Inpatient-Only list on January 1, 2018, which meant TKAs could be performed on a hospital outpatient basis. We sought to understand (1) what the financial implications have been for hospitals, (2) to what extent financial incentives have influenced the adoption of outpatient TKAs across hospitals, (3) whether adoption of outpatient TKAs has impacted the success of hospitals with managing post-acute care (PAC) spend, and (4) the financial implications to Medicare of the adoption of outpatient TKAs. METHODS:We used national patient-level Medicare fee-for-service Part A claims data (100% sample) from January 2018 through June 2019 to calculate the inpatient and outpatient TKA payment rate for each hospital, and the distribution in these payments across the country. We then ran case-level regressions to understand the factors associated with adoption of outpatient TKAs, and the drivers of PAC spend. Finally, we quantified the savings to Medicare. RESULTS:Hospitals on average received $3682 (30%) lower payment from Medicare for outpatient TKA cases, but this varied widely across hospitals. The difference in payment rates across hospitals was not statistically significantly related to their adoption rate of outpatient TKAs. PAC spend was higher for same-day discharges, but lower for cases that stayed at least 1 night. Based on the adoption rate of outpatient TKAs in Q2 2019, Medicare saved $355M on a run rate basis. CONCLUSION/CONCLUSIONS:Hospitals have adopted outpatient TKAs independent of the financial impact. Medicare has benefited from lower PAC spend and lower payments to hospitals.

BACKGROUND:The Association Research Circulation Osseous (ARCO) presents the 2019 revised staging system of osteonecrosis of the femoral head (ONFH) based on the 1994 ARCO classification. METHODS:In October 2018, ARCO established a task force to revise the staging system of ONFH. The task force involved 29 experts who used a web-based survey for international collaboration. Content validity ratios for each answer were calculated to identify the levels of agreement. For the rating queries, a consensus was defined when more than 70% of the panel members scored a 4 or 5 rating on a 5-point scale. RESULTS:Response rates were 93.1%-100%, and through the 4-round Delphi study, the 1994 ARCO classification for ONFH was successfully revised. The final consensus resulted in the following 4-staged system: stage I-X-ray is normal, but either magnetic resonance imaging or bone scan is positive; stage II-X-ray is abnormal (subtle signs of osteosclerosis, focal osteoporosis, or cystic change in the femoral head) but without any evidence of subchondral fracture, fracture in the necrotic portion, or flattening of the femoral head; stage III-fracture in the subchondral or necrotic zone as seen on X-ray or computed tomography scans. This stage is further divided into stage IIIA (early, femoral head depression ≤2 mm) and stage IIIB (late, femoral head depression >2 mm); and stage IV-X-ray evidence of osteoarthritis with accompanying joint space narrowing, acetabular changes, and/or joint destruction. This revised staging system does not incorporate the previous subclassification or quantitation parameters, but the panels agreed on the future development of a separate grading system for predicting disease progression. CONCLUSION/CONCLUSIONS:A staging system has been developed to revise the 1994 ARCO classification for ONFH by an expert panel-based Delphi survey. ARCO approved and recommends this revised system as a universal staging of ONFH.

BACKGROUND:Perioperative pain management for patients undergoing total knee arthroplasty (TKA) improves patient outcomes and facilitates recovery. In this study, we compared the effects of preoperative oral acetaminophen vs intravenous (IV) acetaminophen administered once intraoperatively and once postoperatively. METHODS:Two standardized, multimodal analgesia protocols were compared in patients undergoing primary, unilateral TKA. The oral acetaminophen cohort (OA) received doses of oral acetaminophen preoperatively and an as-needed basis postoperatively (n = 698). The IV acetaminophen cohort (IA) received 2 doses of IV acetaminophen, one intraoperative and one 6 hours postoperatively, with no oral acetaminophen given (n = 318). No other variables were significantly changed during the study period. RESULTS:The IV acetaminophen group demonstrated less narcotic usage on postoperative day 0 (OA: 13.3 mme [morphine mg equivalents], IA: 6.2 mme, P < .001) and overall usage (OA: 66.1 mme, IA: 48.5 mme, P < .001). Pain scores were statistically and clinically significantly decreased in the immediate postoperative (the first 8 hours) for the IA group (OA: patient-reported pain scores of 4.0; IA: patient-reported pain scores of 2.0, P < .001). Both groups progressed and completed their physical therapy similarly for each postoperative day. Length of stay and percent discharge home were slightly improved in the IA group as well, however did not reach statistical difference. CONCLUSION/CONCLUSIONS:An iterative approach to multimodal pain management after TKA led to improvements in narcotic usage, pain scores, and several quality measures. IV acetaminophen is an integral and effective part of our opioid-sparing multimodal pain regimen in TKA.

Introduction/UNASSIGNED:The epidemiology of re-revision total hip arthroplasty (THA) is not yet well-understood. We aim to investigate the epidemiology and risk-factors that are associated with re-revision THA. Methods/UNASSIGNED:288 revision THA were analyzed between 1/2012 and 12/2013. Patients who underwent two or greater revision THA were included. Hips with first-revision due to periprosthetic joint infection (PJI) were excluded. Failure was defined as reoperation. Results/UNASSIGNED:51 re-revision patients were available. Mean age was 59.6 (±14.2 years), 32 (67%) females, average BMI of 28.8 (±5.4), and median ASA 2 (23; 55%). The most common re-revision indications were acetabular component loosening (15; 29%), PJI (13; 25%) and instability (9; 18%). The most common indications for first revision in the re-revision population were acetabular component loosening (11; 27%), polyethylene wear (8; 19%) and instability (8; 19%). There was an increased risk of re-revision failure if the re-revision involved exchanging only the head and polyethylene liner (RR = 1.792; p = 0.017), instability was the first-revision indication (RR = 3.000; p < 0.001), and instability was the re-revision indication (RR = 1.867; p = 0.038). If isolated femoral component revision was indicated during the re-revision, there was a decreased risk of failure (RR = 0.268, p = 0.046). 1-year re-revision survival was 54% (23/43). Discussion/UNASSIGNED:Acetabular component loosening, instability, and PJI were the most common indications for re-revision. Revision due to instability is a recurrent problem that leads to re-revision failure. There was a higher infection rate in the re-revision population compared to published revision PJI. A better understanding of the indications and patient factors that are associated with re-revision failures can help align surgeon and patient expectations in this challenging population.