Recent Increases in Outpatient Total Hip Arthroplasty Have Not Increased Early Complications

Outpatient total hip arthroplasty: robotic assistance reduces 90-Day postoperative events and optimizes outpatient care

PURPOSE

The adoption of robotic-assisted total hip arthroplasty (THA) is increasingly widespread, yet its influence on outcomes in outpatient surgery remains uncertain. This study aimed to evaluate whether robotic assistance reduces the rate of 90-day postoperative events in patients undergoing outpatient THA, compared to those in inpatient procedures.

METHODS

This historical-prospective cohort study analyzed 706 primary THA cases performed between January 2017 and January 2023 by three senior surgeons. Patients were grouped into outpatient (n = 132) and inpatient (n = 576) cohorts. From December 2019, robotic-assisted THA using the MAKO™ system was implemented. Propensity score matching was used to minimize baseline differences between groups. The primary outcome was the occurrence of any event within 90 days post-surgery, including readmissions, reoperations, and other complications. Secondary outcomes included functional scores, length of hospital stay, and intraoperative factors such as blood loss and Operative Room (OR) time.

RESULTS

No significant differences were found between inpatient and outpatient groups in terms of gender, age, BMI, ASA score, or surgeon. The 90-day event rates were similar between the two groups (8.59% vs. 9.38%, p > 0.999). However, outpatient THA was associated with lower blood loss (p = 0.02) and shorter hospital stays (p < 0.001). Multivariate analysis identified prolonged OR time (> 2 h), BMI ≥ 25, and manual surgical techniques as significant risk factors for 90-day events. Robotic-assisted surgery, although not statistically significant (p = 0.105), showed a trend towards reducing complications in outpatient THA.

CONCLUSION

Outpatient THA is a safe alternative to inpatient surgery, with no significant difference in 90-day postoperative events. Robotic-assisted surgery appears to reduce complications, particularly in the outpatient setting, and may optimize outpatient care pathways. Further research is needed to confirm these findings and explore long-term outcomes.

LEVEL OF EVIDENCE

III.

Machine learning to predict periprosthetic joint infections following primary total hip arthroplasty using a national database

INTRODUCTION

Periprosthetic joint infection (PJI) following total hip arthroplasty (THA) remains a devastating complication for patients and surgeons. Given the implications of these infections and the current paucity of risk calculators utilizing machine learning (ML), this study aimed to develop an ML algorithm that could accurately identify risk factors for developing a PJI following primary THA using a national database.

MATERIALS AND METHODS

A total of 51,053 patients who underwent primary THA between 2013 and 2020 were identified using the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database. Demographic, preoperative, intraoperative, and immediate postoperative outcomes were collected. Five ML models were created. The receiver operating characteristic curves, the area under the curve (AUC), calibration plots, slopes, intercepts, and Brier scores were evaluated.

RESULTS

The histogram-based gradient boosting (HGB) model demonstrated good PJI discriminatory ability with an AUC of 0.88. The test-specific metrics supported the model's performance and validation in predicting PJI (calibration curve slope: 0.79; intercept: 0.32; Brier score: 0.007). The top five predictors of PJI were the length of stay (> 3 days), patient weight at the time of surgery (> 94.3 kg), an American Society of Anesthesiologists (ASA) class of 4 or higher, preoperative platelet count (< 249,890/mm3), and preoperative sodium (< 139.5 mEq/L).

CONCLUSION

This study developed a highly specific ML model that could predict patient-specific PJI development following primary THA. Considering the feature importance of the top predictors of infection, surgeons should counsel at-risk patients to optimize resource utilization and potentially improve surgical outcomes.

Discharge Disposition after Total Hip Arthroplasty: A 10-Year Analysis of Trends and Predictors of Nonhome Discharge (2011-2021)

BACKGROUND

Total hip arthroplasty (THA) practices are evolving under the influence of the current value-based healthcare system and bundled payment models. This study aimed to (1) evaluate national trends in discharge disposition and postoperative outcomes after THA, (2) compare discharge cohorts on episode-of-care parameters, and (3) determine predictors of nonhome discharge from 2011 to 2021.

METHODS

The National Surgical Quality Improvement Program database was queried for THA data from 2011 to 2021. A total of 328,380 patients undergoing THA were identified between 2011 and 2021. Of these patients, 276,710 were discharged home and 51,670 were discharged to nonhome locations. Trends of annual discharge disposition, healthcare utilization parameters, and proxies for postoperative complications were reported. A multivariable logistic regression analysis was conducted to identify potential risk factors for nonhome discharge.

RESULTS

The percentage of patients who were discharged to home increased from 70.20% in 2011 to 92.42% in 2021. In those discharged to home, 30-day readmission rates, 30-day major complication rates, length of stay, any wound complications, and need for transfusion all decreased within the past decade. The percentage of patients who were discharged to nonhome locations decreased from 29.80% in 2011 to 7.58% in 2021. In this group, major complication rates within 30 days, length of stay, and need for mechanical ventilation increased from 2011 to 2021. Greater age, female sex, body mass index of <18.5, race, smoking, higher comorbidity burden, and functional status were associated with greater odds ratios of nonhome discharge.

CONCLUSION

Home discharge after THA has increased substantially over the past decade, with more than 90% of patients now being discharged home. However, a small subset of higher-risk patients still requires nonhome discharge and experience worse outcomes. Focused efforts based on known discharge risk factors may allow implementing perioperative optimization strategies to further improve outcomes in this population.

Risk Factors of Failure to Discharge Before "Two Midnights" in Outpatient-Designated Total Hip Arthroplasty

INTRODUCTION

The Centers for Medicare and Medicaid Services removed total hip arthroplasty (THA) from the inpatient-only list but continued to classify admissions as inpatient if they include two midnights, complicating care if an outpatient THA requires extended hospitalization. This study evaluates risk factors of patients undergoing outpatient-designated THA with a length of stay (LOS) ≥ 2 days.

METHODS

A total of 17,063 THA procedures designated as outpatient in the National Surgical Quality Improvement Program database between 2015 and 2020 were stratified by LOS < 2 days (n = 2,294, 13.4%) and LOS ≥ 2 days (n = 14,765, 86.6%). Demographics, comorbidities, and outcomes were compared by univariate analysis. Multivariable regression analysis identified predictors of LOS ≥ 2 days.

RESULTS

Outpatients with extended LOS were older (mean 65.3 vs. 63.5 years; P < 0.01); were more likely to have body mass index (BMI) > 35 (24.0 vs. 17.8%; P < 0.01); and had higher incidences of smoking (15.1% vs. 10.3%; P < 0.01), diabetes (15.4% vs. 9.9%; P < 0.01), chronic obstructive pulmonary disease (4.4% vs. 2.3%; P < 0.01), and hypertension (57.6% vs. 49.2%; P < 0.01). Patients with LOS ≥ 2 days had a higher incidence of surgical site infection ( P < 0.01), hospital readmission ( P < 0.01), and revision surgery ( P < 0.01) over 30 days. Multivariable analysis demonstrated advanced age, female sex, African American race, Hispanic ethnicity, diabetes, smoking, and hypertension were independent risk factors for LOS ≥ 2 days.

CONCLUSION

Despite removal from the inpatient-only list, a subset of outpatient THA remains at risk of an extended LOS. This study informs surgeons on the relevant risk factors of extended stay, enabling early inpatient preauthorization.

Ten Year Experience With Same Day Discharge Outpatient Total Hip Arthroplasty: Patient Demographics Changed, but Safe Outcomes Were Maintained

BACKGROUND

This study aimed to characterize changes in patient demographics and outcomes for same-day discharge total hip arthroplasty (THA) over a 10-year period at a single orthopaedic specialty hospital.

METHODS

A consecutive series of 1,654 patients between 2013 and 2022 who underwent unilateral THA and were discharged on the same calendar day were retrospectively reviewed. Patient demographics, including age, sex, body mass index (BMI), age-adjusted Charlson Comorbidity Index, and American Society of Anesthesiologists (ASA), were collected. Readmissions, complications, and unplanned visits were recorded for 90 days postoperatively. In order to compare the demographics of patients over time, patients were divided into 3 groups: Time Group A (2013 to 2016), Time Group B (2017 to 2019), and Time Group C (2020 to 2022).

RESULTS

The mean age, BMI, ASA score, and CCI increased significantly across each time group. Age increased from 57 years (range, 23 to 77) to 60 years (range, 20 to 87). The BMI increased from 28.1 (range, 18 to 41) to 29.4 (range, 18 to 47). The percentage of patients aged > 70 years almost doubled over time, as did the percentage of patients who had a BMI > 35. Overall complications increased from 3.44 to 6.82%, reflective of the changing health status of patients. Readmissions increased from 0.57 to 1.70% over time. Despite this, there were no readmissions for any patient within the first 24 hours of surgery.

CONCLUSIONS

Our study has 3 important findings. We identified a worsening patient demographic over time with an increasing percentage of patients of advanced age and higher BMI, ASA, and age-adjusted Charlson Comorbidity Index. Also, there was also an increase in readmissions, complications, and unplanned visits. In addition, despite this worsening patient demographic, there were no readmissions within 24 hours and a low rate of readmissions or unplanned visits within the first 48 hours across all time periods, suggesting that same-day discharge-THA continues to be safe in properly selected patients.

Outpatient Total Hip Arthroplasty Volume up Nearly 8-Fold After Regulatory Changes With Expanding Demographics and Unchanging Outcomes: A 10-Year Analysis

BACKGROUND

With the removal of total hip arthroplasty (THA) from the inpatient-only (IPO) lists, the orthopedic landscape across the United States has changed rapidly. Thus, this study aimed to: 1) characterize the change in THA volume for outpatient and inpatient surgeries; 2) elucidate demographical differences before and after removal from the IPO list; and 3) analyze 30-day complications, readmissions, and reoperations.

METHODS

The National Surgical Quality Improvement Program database was queried for primary THAs between January 2010 and December 2021. The primary outcome was the annual volume of outpatient and inpatient THAs. Secondary outcomes involved 30-day complications, readmissions, and reoperations. The variables between cohorts were analyzed using goodness-of-fit Chi-square tests with summary statistics.

RESULTS

Of the 332,423 THAs between 2010 and 2021, 88% were inpatient THAs (n = 292,974) and 12% were outpatient THAs (n = 39,449). From 2019 to 2021, the volume of inpatient THA decreased by 55% (42,779 to 19,075), while outpatient THA increased by 751% (2,518 to 21,424). Patients who had a THA after 2019 were older (P < .001), more commonly women (P < .001), white (P < .001), and more likely American Society of Anesthesiologists Class III (P < .001). The outpatient cohort had fewer 30-day complications, readmissions, and reoperations. The length of stay for both cohorts decreased until 2019, before increasing in 2020 and 2021 for inpatient THAs, while home discharge and operative time increased for both.

CONCLUSIONS

The volume of outpatient THA increased almost eightfold after its removal from the IPO lists in 2020. Despite expanding eligibility with older patients and more comorbidities, 30-day complications, readmissions, and reoperations remain low. These findings support the safe transition to outpatient THA with appropriate patient selection and optimization.

A Cautionary Tale: Malaligned Incentives in Total Hip and Knee Arthroplasty Payment Model Reforms Threaten Promising Innovation and Access to Care

Over the past several years, there have been notable changes and controversies involving Medicare reimbursement for total hip (THA) and total knee arthroplasty (TKA). We have seen the development and implementation of experimental bundled payment model pilot programs goals of improving quality and decreasing overall costs of care during the last decade. Many orthopaedic surgeons have embraced these programs and have demonstrated the ability to succeed in these new models by implementing strategies, such as preservice optimization, to shift care away from inpatient or postdischarge settings and reduce postoperative complications. However, these achievements have been met with continual reductions in surgeon reimbursement rates, lower bundle payment target pricings, modest increases in hospital reimbursement rates, and inappropriate valuations of THA and TKA Common Procedural Terminology (CPT) codes. These challenges have led to an organized advocacy movement and spurred research involving the methods by which improvements have been made throughout the entire episode of arthroplasty care. Collectively, these efforts have recently led to a novel application of CPT codes recognized by payers to potentially capture presurgical optimization work. In this paper, we present an overview of contemporary payment models, summarize notable events involved in the review of THA and TKA CPT codes, review recent changes to THA and TKA reimbursement, and discuss future challenges faced by arthroplasty surgeons that threaten access to high-quality THA and TKA care.

Inconsistent Classification of "Outpatient" Surgeries Leads to Different Outcomes Following Total Hip Arthroplasty in Medicare Beneficiaries: A Critical Analysis

BACKGROUND

With rising utilization of outpatient total hip arthroplasty (THA) in older patients including Medicare beneficiaries, the objective was to compare differences in definition including (1) patient demographics; (2) lengths of stay (LOS); and (3) outcomes of "outpatient" (stated status) versus "same-day discharge" (SDD) (actual LOS = 0 days) utilizing a nationwide database.

METHODS

A national database from 2015 to 2019 was queried for Medicare-aged patients undergoing outpatient THA. Total outpatient THAs (N = 6,072) were defined in one of 2 ways: either "outpatient" by the hospital (N = 2,003) or LOS = 0 days (N = 4,069). Demographics, LOS, discharge destinations, and complications were compared between groups. Logistic regression models computed odds ratios (ORs) for factors leading to complications, readmissions, and nonhome discharges. P values < .008 were significant.

RESULTS

Women (OR: 1.19, P = .002), diabetes mellitus (OR: 1.31, P = .003), general anesthesia (OR: 1.24, P = .001), and longer operative times (≥95 minutes) (OR: 1.82, P < .001) were associated with 'outpatient' designation versus SDD. Within the hospital-defined 'outpatient' cohort, 49.1% (983 of 2,003) were discharged the same day (LOS = 0 days), and 21.8% had LOS 2 or more days. The hospital-defined 'outpatient' cohort had greater odds of nonhome discharges (6.3 versus 2.8%; OR: 1.88, P < .001) compared to SDD surgeries. The incidence was higher for any complication among hospital-defined 'outpatient' designated patients compared to SDD (5.5 versus 3.9%, P = .007).

CONCLUSIONS

Outpatient surgeries may be misleading and often do not correlate with SDD, as over 20% remain in the hospital 2 or more days. Investigators should quantitatively define the "outpatient" status by actual LOS to allow standardization and results comparison.

LEVEL OF EVIDENCE

III.

A neck-sparing short stem shows significantly lower blood loss in total hip arthroplasty compared to a neck-resecting short stem

Short stems are associated with a significantly lower blood loss (BL) compared to straight stems in total hip arthroplasty (THA). Different types of stems differ in design, fixation and level of femoral neck osteotomy. Therefore, we sought to evaluate the difference regarding the perioperative BL between two short stems with different designs in direct anterior approach (DAA). A total of 187 THA performed by a single surgeon were analysed. 107 patients received a neck-resecting (Group A) and 80 patients a neck-sparing short stem (Group B). Blood counts of the day before surgery and of two days after surgery were evaluated. Total blood volume and BL were calculated. Additionally, duration of surgery was analysed. The perioperative BL was significantly lower in Group B (451.4 ± 188.4 ml) compared to Group A (546.6 ± 232.7 ml; p = 0.002). The postoperative haematocrit (31.6 ± 3.7% vs. 30.4 ± 4.4%; p = 0.049) and haemoglobin-level (11.0 ± 1.3 g/dL vs. 10.4 ± 1.5 g/dL; p = 0.002) were significantly higher in Group B. Duration of surgery was significantly shorter in Group B (62.0 ± 11.4 min vs. 72.6 ± 21.8 min; p < 0.001). The use of a neck-sparing short stem leads to a significantly decreased BL compared to a neck-resecting short stem in DAA THA. A less extensively conducted capsular release necessary for optimal femoral exposition might lead to a lower perioperative BL and shorter durations of surgery.

The effect of reduced bone mineral density on elective total hip arthroplasty outcomes

INTRODUCTION

Reduced bone mineral density (BMD) and disruption of normal bony architecture are the characteristics of osteopenia and osteoporosis and in patients undergoing total hip arthroplasty (THA) may cause failure of trabecular ingrowth. The purpose of this study is to evaluate the impact of reduced BMD on outcomes following primary elective THA.

METHODS

A retrospective chart review of 650 elective THAs with a DEXA scan in their electronic health record (EHR) from 2011 to 2020 was conducted at an urban, academic center and a regional, health center. Patients were separated into three cohorts based on their t-score and the World Health Organizations definitions: normal (t-score ≥ - 1), osteopenia (t-score < - 1.0 and > - 2.5), and osteoporosis (t-score ≤ - 2.5). Demographic and outcome data were assessed. Subsidence was assessed for patients with non-cemented THAs. Regression models were used to account for demographic differences.

RESULTS

650 elective THAs, of which only 11 were cemented, were included in the study. Patients with osteopenia and osteoporosis were significantly older than those without (p = 0.002 and p < 0.0001, respectively) and had a lower BMI (p < 0.0001 and p < 0.0001, respectively). PFx was significantly greater in patients with osteoporosis when compared to those with normal BMD (6.5% vs. 1.0%; p = 0.04). No such difference was found between osteoporotic and osteopenic patients. The revision rate was significantly higher for osteoporotic patients than osteopenic patients (7.5% vs. 1.5%; p = 0.04). No such difference was found between the other comparison groups.

CONCLUSION

Patients with osteoporosis were older with reduced BMI and had increased PFx after non-cemented elective THA. Understanding this can help surgeons formulate an appropriate preoperative plan for the treatment of patients with osteoporotic bone undergoing elective THA.

An Increase in Same-day Discharge After Total Joint Arthroplasty During the COVID-19 Pandemic Does Not Influence Patient Outcomes: A Retrospective Cohort Analysis

Background

The coronavirus disease 2019 (COVID-19) pandemic caused major transitions in total joint arthroplasty (TJA), notably with the increased utilization of same-day discharge (SDD) pathways. This study assessed the effect of accelerated discharge pathways following the resumption of elective cases during the COVID-19 pandemic on SDD rates, adverse events, and characteristics associated with successful SDD following total hip and total knee arthroplasty.

Methods

This retrospective study split patients into cohorts: TJA prior to COVID-19 (pre-COVID, July 2019-December 2019) and TJA following the resumption of elective surgeries (post-COVID, July 2020-December 2020). Patient characteristics such as age, sex, body mass index, American Society of Anesthesiologists score, and pertinent comorbidities were analyzed, and length of stay, 30-day emergency department (ED) visit rates, readmissions, and reoperations were compared.

Results

A total of 1333 patients met inclusion criteria that were divided into pre-COVID (692) and post-COVID (641) cohorts. The pre-COVID group had a median age of 69 years (interquartile range 63-76), and the post-COVID group had a median age of 68 years (interquartile range 61-75) (P = .024). SDD increased from 0.1% to 28.9% (P < .001), and length of stay decreased from 1.3 days to 0.89 days (P < .001). There was no change in 30-day ED visits, readmissions, or reoperations (P = .817, P = .470, and P = .643, respectively). There was no difference in ED visits, readmissions, or reoperations in SDD patients. The odds of SDD were associated with age (P < .001, odds ratio [OR] = 0.94), body mass index (P = .006, OR = 0.95), male sex (P < .001, OR = 1.83), and history of tobacco use (P < .001, OR = 1.87).

Conclusions

At our institution, the COVID-19 pandemic accelerated the utilization of SDD pathways without increasing ED visits, readmissions, or reoperations.

Online Crowdsourcing Survey of United States Population Preferences and Perceptions Regarding Outpatient Hip and Knee Arthroplasty

BACKGROUND

Outpatient total joint arthroplasty (TJA) has been shown to be both safe and cost-effective in appropriately selected patients and continues to expand substantially across the United States. Using online crowdsourcing, we aimed to assess population perceptions regarding outpatient TJA and to determine factors associated with preference for outpatient versus inpatient arthroplasty.

METHODS

A closed-ended survey consisting of 39 questions was administered to members of a public platform. Study participants responded to questions regarding demographic factors and outpatient TJA. Validated assessments to capture health literacy and engagement were also used. To determine factors associated with preference for outpatient TJA, multivariable logistic regression analyses were performed.

RESULTS

In total, 900 participants completed the survey. After exclusion of surveys with incomplete data, 725 responses remained for analysis (80.6%). Over half (59.9%) of the survey participants would feel comfortable going home the same day of surgery following TJA. However, two-thirds (64.6%) would prefer to stay in the hospital following TJA. The majority (68.0%) of respondents perceive a hospital setting as the safest location for TJA. The 3 major concerns regarding outpatient TJA were cost, post-operative pain control, and post-operative complication. Among the 111 respondents (15.3%) who would prefer outpatient TJA, 45% would pay more out-of-pocket, 63.1% travel further, and 55.9% would be willing to wait longer to have their surgery performed as an outpatient. On multivariable regressions, those living in a suburban setting (adjusted odds ratios, 95% confidence intervals: 4.2 [1.3-2.7], P = .02) and >60 year old adjusted odds ratios (95% confidence intervals: 8 [2-33.1], P = .004) were more likely to prefer outpatient TJA.

CONCLUSION

Despite the rise in outpatient TJA, the majority of the public appears to prefer inpatient TJA and the minority would expect to be discharged home the same day. Our data can be used to address specific patient concerns regarding outpatient TJA and set realistic expectations for hospital systems and ambulatory facilities.

Early Postoperative Complications in Total Hip and Knee Arthroplasty Before and During the COVID-19 Pandemic: A Retrospective Analysis of 38,234 Patients

Background

The outcomes of total joint arthroplasty during the coronavirus disease 2019 (COVID-19) pandemic are unknown. We sought to compare early postoperative complications in total hip arthroplasty (THA) and total knee arthroplasty (TKA) prior to and during the COVID-19 pandemic.

Methods

Patients in the American College of Surgeons National Surgical Quality Improvement Program database who had THA or TKA in the latter halves (July to December) of 2019 and 2020 were identified. Patients were divided into pre-COVID-19 (2019) and during-COVID-19 (2020) cohorts. Propensity score matching and logistic regression were used to detect correlations between operative period and outcomes. Statistical significance was set at α = 0.05.

Results

A total of 38,234 THA and 61,956 TKA patients were included. There was a significantly higher rate of outpatient procedures in 2020 than that in 2019 for both THA (41.68% vs 6.59%, P < .001) and TKA (41.68% vs 7.56%, P < .001). On matched analysis, surgery in 2020 had lower odds of hospital stay for >1 day (THA: odds ratio [OR] 0.889; P < .001) (TKA: OR 0.644; P < .001) and nonhome discharge (THA: 0.655; P < .001) (TKA: 0.497; P < .001). There was also increased odds of superficial surgical site infection in THA (OR 1.272; P = .040) and myocardial infarction in TKA patients (OR 1.488; P = .042) in 2020 compared to those in 2019. There was no difference in the 15 other outcomes assessed.

Conclusions

Total joint arthroplasty surgery remains safe despite the COVID-19 pandemic. A statistically significant increase was detected in superficial surgical site infection and myocardial infarction risk during 2020 compared to 2019; however, the clinical significance of this is questionable. A shift away from inpatient stay was also present, possibly reflecting efforts to minimize nosocomial exposure to COVID-19.