A Comparison of Relative Value Units in Primary Versus Revision Total Knee Arthroplasty

Trends in reimbursement for primary and revision total elbow arthroplasty

BACKGROUND

Relative value units (RVUs) are an essential component of reimbursement calculations from the Centers for Medicare & Medicaid Services. RVUs are calculated based on physician work, practice expense, and professional liability insurance. Procedures that are more complex, such as revision arthroplasty, require greater levels of physician work and should therefore be assigned a greater RVU. The purpose of this study is to compare RVUs assigned for primary and revision total elbow arthroplasty (TEA).

METHODS

The National Surgical Quality Improvement Program database was used to collect all primary and revision total elbow arthroplasties performed between January 2015 and December 2017. Variables collected included age at time of surgery, RVUs assigned for the procedure, and operative time.

RESULTS

A total of 359 cases (282 primary TEA, 77 revision TEA) were included in this study. Mean RVUs for primary TEA was 21.4 (2.0 standard deviation [SD]) vs. 24.4 (1.7 SD) for revision arthroplasty (P < .001). Mean operative time for primary TEA was 137.9 minutes (24.4 SD) vs. 185.5 minutes (99.7 SD) for revision TEA (P < .001). The RVU per minute for primary TEA was 0.16 and revision TEA was 0.13 (P < .001). This amounts to a yearly reimbursement difference of $71,024 in favor of primary TEA over revision TEA.

CONCLUSION

The current reimbursement model does not adequately account for increased operative time, technical demand, and pre- and postoperative care associated with revision elbow arthroplasty compared with primary TEA. This leads to a financial advantage on performing primary TEA.

Reimbursement for Hip Fractures: The Impact of Varied Current Procedural Terminology Coding Using Relative Value Units

BACKGROUND

Many orthopedic practices routinely code hip fracture hemiarthroplasty as Current Procedural Terminology (CPT) 27125 even though 27236 is the correct CPT code. Our objective is to determine the financial impact this simple mistake has on surgeon reimbursement.

METHODS

Our data comprised cases assigned International Classification of Diseases, Tenth Revision code S72.001A through S72.035A and CPT code 27125 or 27236 within the American College of Surgeons National Surgical Quality Improvement Program 2016-2017 database. Relative value units (RVUs) per CPT code and the Centers for Medicare and Medicaid Services reported that RVU conversion factor of $36.0896 per 1 RVU was used to calculate reimbursement per case. The dollar difference and percent difference per case was then calculated between cases assigned CPT code 27125 and those assigned 27236.

RESULTS

Our total sample consisted of 12,287 National Surgical Quality Improvement Program cases. Of those, 4185 (34%) were cases of a hip fracture treated with hemiarthroplasty that were incorrectly coded as CPT code 27125. That error in coding results in a decrease in reimbursement of $35.01 per case, a 5.51% difference.

CONCLUSION

Since the current healthcare reimbursement model relies solely on CPT codes to determine RVUs, it is imperative that orthopedic surgeons understand the financial impact of incorrect coding. Although correct coding of hemiarthroplasty procedures for hip fractures is an easy task to fix in the future, we hope that through this study a greater emphasis is placed on coding in orthopedic surgery.

Laparoscopic Inguinal Hernia Repair: Undervalued by the Relative Value Unit System

Work relative value units (wRVUs) serve as a proxy of surgeon's effort, technical skill, and time to determine reimbursement. The aim of this study is to determine how accurately wRVUs reflect the work effort of surgeons performing laparoscopic inguinal hernia repair (LIHR) as compared to open repair (OIHR). Within the National Surgical Quality Improvement Program database, 40 099 patients who underwent LIHR and 99 176 patients who underwent OIHR between 2012 and 2017 were identified. Mean wRVUs, wRVUs per minute, and operative times were compared between 8 groups based on clinical factors (unilateral vs. bilateral; obstructed vs. non-obstructed; primary vs. recurrent; 2 × 2 × 2 = 8). In both aggregate and matched cohorts, wRVUs for LIHR were significantly lower than OIHR in all 8 categories (P < .001). On regression analysis, the mean difference in assigned vs. calculated relative value units (RVUs) was most divergent among unilateral, recurrent, obstructed IHR (3.12 mean RVUs, P < .001). Despite the rising utilization of LIHR, current wRVUs significantly undervalue this technique across all categories and consequently the work of surgeons who perform laparoscopic procedures. This RVU discrepancy in an increasing minimally invasive, value-driven surgical environment calls for more objective criteria to assign RVUs, whereby the value is measured by operative complexity-patient clinical factors and severity of the hernia itself-not solely operative technique.

Are Orthopaedic Trauma Surgeons Being Adequately Compensated for Treating Nonunions of the Femoral Shaft?: An Analysis of Relative Value Units

Introduction:

We evaluated differences in reimbursement rates between native femoral shaft fractures treated with an intramedullary nail versus those undergoing repair of nonunion of femoral shaft fractures.

Methods:

The 2016 to 2017 American College of Surgeons—National Surgical Quality Improvement Program database was queried using International Classification of Diseases 10th Edition diagnosis codes and Current Procedural Terminology codes to identify patients undergoing surgery for native femoral shaft fractures and/or repair of nonunion of femoral shaft fracture with/without grafts.

Results:

The mean total relative value unit (RVU) and surgical time for each group were as follows: (1) native (RVU = 19.70, surgical time = 97.4 minutes), (2) nonunion w/out graft (RVU = 17.23, surgical time = 135.8 minutes), (3) nonunion w/graft (RVU = 18.88, surgical time = 164.5 minutes). Reimbursement rates decreased notably as complexity of case grew (native = $8.74/min versus nonunion w/graft = $6.07/min versus nonunion w/graft = $5.27/min; P < 0.001). The average reimbursement/case was $707 for native femoral shaft fracture, $618 for repair of nonunion w/out graft, and $678 for repair of nonunion with bone graft.

Discussion:

The study highlights the need for a change in the RVUs assigned to nonunions of the femoral shaft to ensure that the value of physician intensity is retained in future RVU evaluations.

Developing a personalized outcome prediction tool for knee arthroplasty

AIMS

The purpose of this study was to develop a personalized outcome prediction tool, to be used with knee arthroplasty patients, that predicts outcomes (lengths of stay (LOS), 90 day readmission, and one-year patient-reported outcome measures (PROMs) on an individual basis and allows for dynamic modifiable risk factors.

METHODS

Data were prospectively collected on all patients who underwent total or unicompartmental knee arthroplasty at a between July 2015 and June 2018. Cohort 1 (n = 5,958) was utilized to develop models for LOS and 90 day readmission. Cohort 2 (n = 2,391, surgery date 2015 to 2017) was utilized to develop models for one-year improvements in Knee Injury and Osteoarthritis Outcome Score (KOOS) pain score, KOOS function score, and KOOS quality of life (QOL) score. Model accuracies within the imputed data set were assessed through cross-validation with root mean square errors (RMSEs) and mean absolute errors (MAEs) for the LOS and PROMs models, and the index of prediction accuracy (IPA), and area under the curve (AUC) for the readmission models. Model accuracies in new patient data sets were assessed with AUC.

RESULTS

Within the imputed datasets, the LOS (RMSE 1.161) and PROMs models (RMSE 15.775, 11.056, 21.680 for KOOS pain, function, and QOL, respectively) demonstrated good accuracy. For all models, the accuracy of predicting outcomes in a new set of patients were consistent with the cross-validation accuracy overall. Upon validation with a new patient dataset, the LOS and readmission models demonstrated high accuracy (71.5% and 65.0%, respectively). Similarly, the one-year PROMs improvement models demonstrated high accuracy in predicting ten-point improvements in KOOS pain (72.1%), function (72.9%), and QOL (70.8%) scores.

CONCLUSION

The data-driven models developed in this study offer scalable predictive tools that can accurately estimate the likelihood of improved pain, function, and quality of life one year after knee arthroplasty as well as LOS and 90 day readmission. Cite this article: Bone Joint J 2020;102-B(9):1183-1193.

Revision of total knee arthroplasty with the use of patient-specific instruments: an alternative surgical technique

INTRODUCTION

Accuracy in the placement of components in revision total knee arthroplasty (R-TKA) surgery is sometimes challenging. The applicability of patient‑specific instruments (PSI) in knee surgery has progressively expanded to types of surgery other than primary arthroplasty. Could this assistive technology be used to facilitate accurate R-TKA surgery? The aim of the current manuscript is to describe this new application of PSI for revision of TKA-to-TKA and to provide a step-by-step technical guideline for use.

AREAS COVERED

We will describe the application and a detailed description of PSI technology to TKA revision surgery, step-by-step, from CT images acquisition for preoperative planning and PSI blocks production to the surgery.

EXPERT COMMENTARY

The system can facilitate the accomplishment of the bony cuts for optimal implant placement and that can be useful in minimally altering the femoral and the tibial joint line. It is obvious that technology alone will not replace surgical skill and that accuracy of the system will also depend on the quality of the CT images and the ability of the software to prevent metal artifacts. Despite that, our initial results are promising and prove that the concept of applying PSI technology to the R-TKA surgery is feasible.

Sex-Based Disparities in the Hourly Earnings of Surgeons in the Fee-for-Service System in Ontario, Canada

Importance

Sex-based income disparities are well documented in medicine and most pronounced in surgery. These disparities are commonly attributed to differences in hours worked. One proposed solution to close the earnings gap is a fee-for-service payment system, which is theoretically free of bias. However, it is unclear whether a sex-based earnings gap persists in a fee-for-service system when earnings are measured on the basis of hours worked.

Objective

To determine whether male and female surgeons have similar earnings for each hour spent operating in a fee-for-service system.

Design, Setting, and Participants

This cross-sectional, population-based study used administrative databases from a fee-for-service, single-payer health system in Ontario, Canada. Surgeons who submitted claims for surgical procedures performed between January 1, 2014, and December 31, 2016, were included. Data analysis took place from February 2018 to December 2018.

Exposures

Surgeon sex.

Main Outcomes and Measures

This study compared earnings per hour spent operating between male and female surgeons and earnings stratified by surgical specialty in a matched analysis. We explored factors potentially associated with earnings disparities, including differences in procedure duration and type between male and female surgeons and hourly earnings for procedures performed primarily on male vs female patients.

Results

We identified 1 508 471 surgical procedures claimed by 3275 surgeons. Female surgeons had practiced fewer years than male surgeons (median [interquartile range], 8.4 [2.9-16.6] vs 14.7 [5.9-25.7] years; P < .001), and the largest proportion of female surgeons practiced gynecology (400 of 819 female surgeons [48.8%]). Hourly earnings for female surgeons were 24% lower than for male surgeons (relative rate, 0.76 [95% CI, 0.74-0.79]; P < .001). This disparity persisted after adjusting for specialty and in matched analysis stratified by specialty, with the largest mean differences in cardiothoracic surgery (in US dollars: $59.64/hour) and orthopedic surgery ($55.45/hour). There were no differences in time taken by male and female surgeons to perform common procedures; however, female surgeons more commonly performed procedures with the lowest hourly earnings.

Conclusions and Relevance

Even within a fee-for-service system, male and female surgeons do not have equal earnings for equal hours spent working, suggesting that the opportunity to perform the most lucrative surgical procedures is greater for men than women. These findings call for a comprehensive analysis of drivers of sex-based earning disparities, including referral patterns, and highlight the need for systems-level solutions.

Barriers to Revision Total Hip Service Lines: A Surgeon's Perspective Through a Deterministic Financial Model

BACKGROUND

Revision THA represents approximately 5% to 10% of all THAs. Despite the complexity of these procedures, revision arthroplasty service lines are generally absent even at high-volume orthopaedic centers. We wanted to evaluate whether financial compensation is a barrier for the development of revision THA service lines as assessed by RVUs.

QUESTIONS/PURPOSES

Therefore, we asked: (1) Are physicians fairly compensated for revision THA on a per-minute basis compared with primary THA? (2) Are physicians fairly compensated for revision THA on a per-day basis compared with primary THA?

METHODS

Our deterministic financial model was derived from retrospective data of all patients undergoing primary or revision THA between January 2016 and June 2018 at an academic healthcare organization. Patients were divided into five cohorts based on their surgical procedure: primary THA, head and liner exchange, acetabular component revision THA, femoral component revision THA, and combined femoral and acetabular component revision THA. Mean surgical times were calculated for each cohort, and each cohort was assigned a relative value unit (RVU) derived from the 2018 Center for Medicaid and Medicare assigned RVU fee schedule. Using a combination of mean surgical time and RVUs rewarded for each procedure, three models were developed to assess the financial incentive to perform THA services for each cohort. These models included: (1) RVUs earned per the mean surgical time, (2) RVUs earned for a single operating room for a full day of THAs, and (3) RVUs earned for two operating rooms for a full day of primary THAs versus a single rooms for a full day of revision THAs. A sixth cohort was added in the latter two models to more accurately reflect the variety in a typical surgical day. This consisted of a blend of revision THAs: one acetabular, one femoral, and one full revision. The RVUs generated in each model were compared across the cohorts.

RESULTS

Compared with primary THA by RVU per minute, in revision THA, head and liner exchange demonstrated a 4% per minute deficit, acetabular component revision demonstrated a 29% deficit, femoral component revision demonstrated a 32% deficit, and full revision demonstrated a 27% deficit. Compared with primary service lines with one room, revision surgeons with a variety of revision THA surgeries lost 26% potential relative value units per day. Compared with a two-room primary THA service, revision surgeons lost 55% potential relative value units per day.

CONCLUSIONS

In a comparison of relative value units of a typical two-room primary THA service line versus those of a dedicated revision THA service line, we found that revision specialists may lose between 28% and 55% of their RVU earnings. The current Centers for Medicare and Medicaid Services reimbursement model is not viable for the arthroplasty surgeon and limits patient access to revision THA specialists.

LEVEL OF EVIDENCE

Level III, economic and decision analysis.

Low Hospital Volume Increases Re-Revision Rate Following Aseptic Revision Total Knee Arthroplasty: An Analysis of 23,644 Cases

BACKGROUND

Along with rising numbers of primary total knee arthroplasty (TKA), the number of revision total knee arthroplasties (R-TKAs) has been increasing. R-TKA is a complex procedure requiring special instruments, implants, and surgical skills. Therefore it is likely that hospitals with more R-TKAs have more experience with this type of surgery and therefore fewer complications. The purpose of this study is to evaluate the relationship between hospital volume and re-revision rate following R-TKA.

METHODS

Using nationwide healthcare insurance data for inpatient hospital treatment, 23,644 aseptic R-TKAs in 21,573 patients treated between January 2013 and December 2017 were analyzed. Outcomes were 90-day mortality, 1-year re-revision rate, and in-house adverse events. The effect of hospital volumes on outcomes were analyzed by means of multivariate logistic regression. Adjusted odds ratios (OR) and 95% confidence intervals (CI) were calculated.

RESULTS

Hospital volume had a significant effect on 1-year re-revision rate (≤12 R-TKA/a: OR 1.44, CI 1.20-1.72; 13-24 R-TKA/a: OR 1.43, CI 1.20-1.71; 25-52 R-TKA/a: OR 1.13, CI 0.94-1.35; ≥53 R-TKA/a: reference). Ninety-day mortality and major in-house adverse events decreased with increasing volume per year, but after risk adjustment this was not statistically significant.

CONCLUSION

We found evidence of higher risk for re-revision surgery in hospitals with fewer than 25 R-TKA per year. It might contribute to improved patient care if complex elective procedures like R-TKA which require experience and a specific logistic background were performed in specialized centers.

Work Relative Value Units Do Not Adequately Support the Burden of Infection Management in Revision Knee Arthroplasty

BACKGROUND

Revision total knee arthroplasty for infection is challenging. Septic revisions, whether 1-stage or 2-stage, may require more time and effort than comparable aseptic revisions. However, the burden of infection may not be reflected by the relative value units (RVUs) assigned to septic revision compared with aseptic revision. The purposes of this study were to compare the RVUs of aseptic and septic revision total knee arthroplasties and to calculate the RVU per minute for work effort.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database was analyzed for the years 2006 to 2017. The Current Procedural Terminology (CPT) code 27487 and the International Classification of Diseases, Ninth Revision (ICD-9) code 996.XX, excluding 996.6X, were used to identify all aseptic revision total knee arthroplasties (n = 12,907). The CPT code 27487 and the ICD-9 code 996.6X were used to determine all 1-stage septic revision total knee arthroplasties (n = 891). The CPT codes 27488 and 11981 were used to identify the first stage of a 2-stage revision (n = 293). The CPT codes 27447 and 11982 were used to identify the second stage of a 2-stage revision (n = 279). After 4:1 propensity score matching, 274 cases were identified per septic cohort (aseptic single-stage: n = 1,096). The RVU-to-dollar conversion factor was provided by the U.S. Centers for Medicare & Medicaid Services (CMS), and RVU dollar valuations were calculated.

RESULTS

The septic second-stage revision was used as the control group for comparisons. The RVU per minute for the aseptic 2-component revision was 0.215, from a mean operative time of 148.95 minutes. The RVU per minute for the septic, 2-component, 1-stage revision was 0.199, from a mean operative time of 160.6 minutes. For septic, 2-stage revisions, the first-stage RVU per minute was 0.157, from a mean operative time of 138.1 minutes. The second-stage RVU per minute was 0.144, from a mean operative time of 170.0 minutes. Two-component aseptic revision total knee arthroplasty was valued the highest.

CONCLUSIONS

Despite the increased complexity and worse postoperative outcomes associated with revision total knee arthroplasties for infection, the current physician reimbursement does not account for these challenges. This inadequate compensation may discourage providers from performing these operations and, in turn, make it more difficult for patients with periprosthetic joint infection to receive the necessary treatment. Therefore, the CPT code revaluation may be warranted for these procedures.

Does Patient Experience After a Total Knee Arthroplasty Predict Readmission?

BACKGROUND

To our knowledge, the relationship between patient Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS) scores and patient outcomes in total knee arthroplasty (TKA) has not yet been analyzed. Therefore, the purpose of this study is to determine whether readmissions within the 30 or 90 days postoperative window after TKA were predicted by patient satisfaction scores, as measured by the HCAHPS survey.

METHODS

We analyzed HCAHPS survey scores from all patients who underwent primary or revision TKA at our institution between January 1, 2016 and September 1, 2016. Demographic readmission information, preoperative baseline health status measures, validated patient-reported pain and joint function measures, and HCAHPS survey scores were collected. To determine whether 30-day or 90-day readmissions were independently associated with HCAHPS scores, statistical analyses were conducted using chi-squared and Student's t-tests for categorical and continuous variables. Multivariable regression analysis adjusted for patient-level risk factors.

RESULTS

Patients readmitted within 30 days were significantly less likely to choose the highest rating on survey questions in several dimensions of patient satisfaction when compared to patients who were not readmitted. These dimensions included physician communication (P = .045), discharge information (P = .016), and transition of care (P = .044). Similarly, patients who were readmitted within 90 days were less likely to choose the highest rating in survey questions that pertained to physician communication (P = .046), medication information (P = .040), and quietness of the hospital environment (P = .048).

CONCLUSION

Our results show that readmission is predicted by lower patient satisfaction scores in several dimensions of patient care including physician communication, hospital environment, medication information, discharge information, and transition of care.

One-Stage Periprosthetic Joint Infection Reimbursement-Is It Worth The Effort?

BACKGROUND

One-stage protocols for the management of periprosthetic infection take an extended period of time requiring two separate preps and sets of instruments to ensure optimal sterility. While intraoperative service time is one part of the reimbursement algorithm, reimbursement has lagged behind for single-stage treatment with respect to the time and resources necessary to perform these complex treatment regimens. If one-stage results are shown to be acceptable, but not reimbursed appropriately, surgeons will be discouraged from managing periprosthetic joint infection (PJI) in a one-stage fashion.

METHODS

The reimbursement and operative time for 50 PJI procedures were compared with 250 primary total hips and 250 primary total knees by the same 4 surgeons.

RESULTS

The average reimbursement for a one-stage knee procedure was $2,597.08, with an average intraoperative service time of 259 minutes ($601.60/h). The average reimbursement for a primary total knee was $2,435.00, with an average intraoperative service time of 100 minutes ($1,461/h). The average reimbursement for a one-stage hip procedure was $2,826.17, with an average intraoperative service time of 311 minutes ($545.24/h). The average reimbursement for a primary total hip was $2,754.71 with an average intraoperative service time of 104 minutes ($1,589.26/h).

CONCLUSION

One-stage procedures for PJI are reimbursed at approximately 1/3 the hourly rate of a primary procedure, which may discourage surgeons from selecting this treatment alternative even if recent studies confirm efficacy. Payers should be encouraged to reimburse physicians commensurate with the intraoperative service time needed to perform a one-stage procedure as adoption will decrease morbidity and save the healthcare system financially.

A dedicated revision total knee service: a surgeon’s perspective

AIMS

Revision total knee arthroplasty (rTKA) accounts for approximately 5% to 10% of all TKAs. Although the complexity of these procedures is well recognized, few investigators have evaluated the cost and value-added with the implementation of a dedicated revision arthroplasty service. The aim of the present study is to compare and contrast surgeon productivity in several differing models of activity.

MATERIALS AND METHODS

All patients that underwent primary or revision TKA from January 2016 to June 2018 were included as the primary source of data. All rTKA patients were categorized by the number of components revised (e.g. liner exchange, two or more components). Three models were used to assess the potential surgical productivity of a dedicated rTKA service : 1) work relative value unit (RVU) versus mean surgical time; 2) primary TKA with a single operating theatre (OT) versus rTKA with a single OT; and 3) primary TKA with two OTs versus rTKA with a single OT.

RESULTS

In total, 4570 procedures were performed: 4128 primary TKAs, 51 TKA liner exchanges, and 391 full rTKAs. Surgical time was significantly different between the primary TKA, liner exchange, and rTKA cohorts (100.6, 97.1, and 141.7 minutes, respectively; p < 0.001). Primary TKA yielded a mean of 7.1% more RVU/min per procedure than rTKA. Our one-OT model demonstrated that primary TKA (n = 4) had a 1.9% RVU/day advantage over rTKA (n = 3). If two OTs are used for primary TKA (n = 6), the outcome strongly favours primary TKA by an added 34.6% RVUs/day.

CONCLUSION

Our results suggest that a dedicated rTKA service would lead to lower surgeon remuneration based on the current RVU paradigm. Revision arthroplasty specialists may need additional or alternative incentives to promote the development of a dedicated revision service. Through such an approach, healthcare organizations could enhance the quality of care provided, but surgeon productivity measures would need to be adjusted to reflect the burden of these cases. Cite this article: Bone Joint J 2019;101-B:675-681.

A comparison of peri-operative outcomes between elective and non-elective total hip arthroplasties

Background

Elective total hip arthroplasties (THAs) entail a more extensive pre-operative planning process compared to non-elective THAs and this may contribute to a disparity in outcomes. However, the differences in peri- and post-operative outcomes between elective and non-elective THAs remain unclear. Therefore, the purpose of this study was to: (I) determine nationwide trends in operative times and (II) evaluate the association between surgery type, elective or non-elective with respect to (I) operative times; (II) hospital lengths-of-stay (LOS); (III) discharge disposition; (IV) 30-day post-operative complications; (V) reoperations; and (VI) readmissions.

Methods

The NSQIP database was queried for all primary THAs (CPT code 27130) performed between 2011 and 2016. This yielded 130,261 cases, which were then stratified into elective (n=125,293) and non-elective (n=4,968) cases. One-way analysis of variance (ANOVA) were used to evaluate the associations between operative times and surgery year. Univariate analyses of surgery type with the following outcomes of interest were also performed: operative times, LOS, and discharge disposition as well as 30-day complication, reoperation, and readmission rates. A multiple linear regression model was used to evaluate the relationships of operative times and LOS with surgery types after adjusting for surgery year and patient factors [age, sex, body mass index (BMI), and American Society of Anesthesiologists (ASA) score]. A log-transformed dependent variable was used to calculate the percentage difference in mean operative times and LOS. Multivariate logistic regression models adjusted for patient factors and year of surgery were used to evaluate associations of surgery type with complication, reoperation, and readmission rates.

Results

Over the 6-year period, mean operative times (93 vs. 103 minutes, P<0.001) and LOS (3 vs. 6 days, P<0.001) were significantly shorter in elective cases compared to non-elective cases. The relationships between operative times or LOS and surgery type remained significant even after adjusting for age, sex, BMI, ASA, and year of surgery (P<0.001). Compared to the non-elective cohort, patients in the elective cohort were more likely to be discharged home (74% vs. 69%, P<0.001). Elective patients had lower rates of several 30-day complications including deep SSI (P<0.001), transfusions (P<0.001), sepsis (P<0.001), and readmission (P<0.005) compared to non-elective patients. These associations remained significant after accounting for potential confounders with multivariate logistic regression.

Conclusions

Findings from this study showed that elective THAs, in which there is more potential for pre-operative planning, were associated with shorter operative times and LOS, as well as fewer complication and readmission rates. These results likely reflect the development of more efficient surgical techniques and improved pre- and intra-operative planning guides.

A comparison of relative value units in revision hip versus revision knee arthroplasty

The purpose of this study was to compare the: 1) RVUs; 2) lengths-of-surgery; 3) RVU per minute between revision hip (THA) and knee (TKA) arthroplasties; and 4) perform an annualized surgeon cost analysis. Using the ACS-NSQIP from 2008 to 2015, 8081 revision TKAs, 7233 THAs were compared. Revision THA had greater mean RVUs (30.27 vs. 27.10 RVUs, p < 0.001), operative times (152 vs. 149 min, p < 0.001), and RVU/minute (0.3 vs. 0.2 RVUs per minute, p < 0.001). Cost analysis yielded and annual $89,922.73 difference. Revision THA, therefore, is reimbursed at a significantly higher "hourly rate," when compared to revision TKA.