Hospital Volume and Postoperative Infections in Total Knee Arthroplasty

Low-Volume Surgeons Operating at High-Volume Hospitals Have Low Rates of Periprosthetic Joint Infection After Hip and Knee Arthroplasty

BACKGROUND

The relationship between surgeon and hospital case volumes and postoperative risk following total hip arthroplasty and total knee arthroplasty (THA and TKA) has been described independently. This study aimed to assess the risk of periprosthetic joint infection (PJI) following primary TKA and THA to determine if lower volume surgeons operating at higher volume centers would have lower rates of complications compared to lower volume surgeons operating at lower volume hospitals.

METHODS

A health care database was used to retrospectively identify all primary and elective total joint arthroplasties from October 2015 to December 2021. Using restricted cubic splines, high-volume hospitals were defined using Markov chain Monte Carlo simulation, which identified a volume beyond which PJI rates no longer decreased significantly with increasing hospital volume. A similar methodology was used to identify low-volume surgeons operating in high- and low-volume hospitals. There were 605,254 patients who underwent total joint arthroplasty (THA: 37.71%; TKA: 62.29%) by low-volume surgeons (< 57 THAs and < 68 TKAs) identified and divided into high- and low-volume hospital cohorts. High-volume hospitals were defined as > 508 THA and > 812 TKAs per year, and low-volume hospitals were defined as < 145 THAs and < 243 TKAs per year. Multivariable models accounting for potential confounding covariates were created to determine the odds of PJI between cohorts.

RESULTS

After taking confounding variables into account, low-volume surgeons at high-volume hospitals had lower rates of PJI relative to their counterparts at low-volume hospitals (THA 0.67 versus 0.80%, adjusted odds ratio = 0.69 [95% confidence interval = 0.54 to 0.88], P = 0.002; TKA 0.51 versus 0.69%, adjusted odds ratio = 0.73, [95% confidence interval = 0.61 to 0.87], P = 0.007).

CONCLUSIONS

Increasing institutional case volume may mitigate the increased risk of PJI associated with low annual surgeon case volume.

Trends in Complications Following Pediatric Anterior Cruciate Ligament Reconstruction as Reported to the American Board of Orthopaedic Surgery Part II Oral Examination Database

Background

Pediatric anterior cruciate ligament reconstructions (ACLR) have increased dramatically in recent years. However, a comprehensive list of short-term complications related to this procedure has yet to be reported. This study aimed to report complication rates in pediatric ACLR using submissions to the American Board of Orthopaedic Surgery (ABOS) Part II Oral Examination. A secondary goal was to assess the relationship of complications with patient sex, geographic region of surgery, surgical volume, and surgeon fellowship training.

Methods

A query was submitted to the ABOS Part II Oral Examination Case List Database for all ACLR performed in patients younger than 19 years between 2000 and 2021. Surgeon fellowship training, geographic region of surgery, and patient demographics were included, along with medical, surgical, and anesthetic complications, reoperation, and readmission. Statistic comparisons used chi-square tests for categorical variables with significance set at P < 0.05.

Results

Surgical complications were the most common type of complication, present in 10.1% of pediatric ACLR. Stiffness (3.6%) and infection (1.5%) were the most prevalent surgical complications. Females had higher rates of overall complications than males (11.9% vs. 10.4%, P = 0.010). Females also had higher rates of surgical complications (10.7%-9.5%, P = 0.019) -- specifically stiffness (5.0%-2.2%, P < 0.001). However, males had higher rates of infection (1.8% vs. 1.3%, P = 0.047). Geographic analyses showed higher infection rates in Hawaii and Alaska and lower surgical complication rates in the Northwest region. Procedures completed by surgeons with a fellowship training other than Sports Medicine and/or Pediatric Orthopaedics had lower rates of overall complications (8.9%, P < 0.001) and surgical complications (8.3%, P < 0.001).

Conclusion

This study establishes that female pediatric and adolescent patients are at an increased risk for complications following ACLR. Arthrofibrosis was more than twice as common in females than in males. Geographic region and fellowship training may be associated with complications in this population.

Study design

Cross-Sectional Study.

Key Concepts

(1)Complications following ACL reconstruction may be associated with geographic region and fellowship training.(2)Females present with more short-term complications following ACL reconstruction.(3)There was a higher reported infection rate overall for surgeons in their board collection period than infection rates in the literature, with males having an overall higher infection rate than females.(4)Arthrofibrosis is more than twice as common in females than males following ACL reconstruction.

Level of Evidence

III.

Using the Stratum-Specific Likelihood Ratio Method to Derive Outcome-Based Hospital Volume Categories for Total Knee Replacement

BACKGROUND

Evidence of higher hospital volume being associated with improved outcomes for patients undergoing total knee replacement (TKR) is mostly based on arbitrary distribution-based thresholds.

OBJECTIVE

We aimed to define outcome-based volume thresholds using data from a national database.

METHODS

We used the MedPAR Limited Data Set inpatient data from 2010-2015 to identify patients who had undergone primary TKR. Surgical and TKR specific complications occurring within the index hospitalization and all-cause readmission within 90 days were considered adverse events. We derived an average annual TKR case volume for each hospital and applied the stratum-specific likelihood ratio method to determine volume categories indicative of a similar likelihood of 90-day post-operative complications. Hierarchical multivariable logistic regression with a random intercept for hospital nested within study year and adjusted for patient and hospital characteristics was performed to determine if these volume thresholds were still associated with the odds of 90-day readmission for complications after adjustment.

RESULTS

SSLR analysis yielded 4 hospital volume categories based on the likelihood of 90-day postoperative complications: 1-31 (low), 32-127 (medium), 128-248 (high), and 429+ (very high) TKRs performed per year. The results of the hierarchical multivariable logistic regression showed significantly increased odds of 90-day complications at lower volume categories. Sensitivity analyses confirmed our main findings.

CONCLUSIONS

This study is the first to provide national-level volume categories that are evidence-based. Publicizing these thresholds may enhance quality measures available to patients, providers, and payors.

Treating Hepatitis C Before Total Knee Arthroplasty is Cost-Effective: A Markov Analysis

BACKGROUND

Patients who have the hepatitis C virus (HCV) have increased mortality and complication rates following total knee arthroplasty (TKA). Recent advances in HCV therapy have enabled clinicians to eradicate the disease using direct-acting antivirals (DAAs); however, its cost-effectiveness before TKA remains to be demonstrated. The aim of this study was to perform a cost-effectiveness analysis comparing no therapy to DAAs before TKA.

METHODS

A Markov model using input values from the published literature was performed to evaluate the cost-effectiveness of DAA treatment before TKA. Input values included event probabilities, mortality, cost, and health state quality-adjusted life-year (QALY) values for patients who have and do not have HCV. Patients who have HCV were modeled to have an increased rate of periprosthetic joint infection (PJI) infection (9.9 to 0.7%). The incremental cost-effectiveness ratio (ICER) of no therapy versus DAA was compared to a willingness-to-pay threshold of $100,000/QALY. Sensitivity analyses were performed to investigate the effects of uncertainty associated with input variables.

RESULTS

Total knee arthroplasty in the setting of no therapy and DAA added 8.1 and 13.5 QALYs at a cost of $25,000 and $114,900. The ICER associated with DAA in comparison to no therapy was $16,800/QALY, below the willingness-to-pay threshold of $100,000/QALY. Sensitivity analyses demonstrated that the ICER was affected by patient age, inflation rate, DAA cost and effectiveness, HCV-associated mortality, and DAA-induced reduction in PJI rate.

CONCLUSION

Direct-acting antiviral treatment before TKA reduces risk of PJI and is cost-effective. Strong consideration should be given to treating patients who have HCV before elective TKA.

LEVEL OF EVIDENCE

Cost-effectiveness Analysis; Level III.

Black Patients are More Likely to Undergo Early Revision Total Knee Arthroplasty in a Matched Cohort Regardless of Surgeon Experience

BACKGROUND

Black patients are at an increased risk of aseptic revision total knee arthroplasty (TKA) when compared to White patients. The goal of this study was to determine whether racial disparities in revision TKA risk are related to surgeon characteristics.

METHODS

This was an observational cohort study. We used inpatient administrative data to identify Black patients who underwent unilateral primary TKA in New York State. There were 21,948 Black patients who were matched 1:1 to White patients on age, sex, ethnicity, and insurance type. The primary outcome was aseptic revision TKA within 2 years of primary TKA. We calculated annual surgeon TKA volume and identified surgeon characteristics such as training in North America, board certification, and years of experience.

RESULTS

Black patients had a higher odds of aseptic revision TKA (odds ratio (OR) 1.32, 95% CI 1.12-1.54, P < .001) and were disproportionately cared for by low volume surgeons (≤12 TKA/year). The relationship between low volume surgeons and risk of aseptic revision was not statistically significant (OR 1.24, 95% CI 0.72-2.11, P = .436). The adjusted odds ratio (aOR) for aseptic revision TKA in Black versus White patients varied across surgeon/hospital TKA volume category pairs, with the greatest aOR when TKA were performed by the highest volume surgeons at the highest volume hospitals (aOR 2.8, 95% CI 0.98- 8.09, P = .055).

CONCLUSION

Black patients were more likely to undergo aseptic TKA revision than matched White patients. This disparity was not explained by surgeon characteristics.

Length of stay and inpatient charges of total knee arthroplasty in China: analysis of a national database

BACKGROUND

There are limited data on the resource utilization of total knee arthroplasty (TKA) in China. This study aimed to examine the length of stay (LOS) and inpatient charges of TKA in China, and to investigate their determinants.

METHODS

We included patients undergoing primary TKA in the Hospital Quality Monitoring System in China between 2013 and 2019. LOS and inpatient charges were obtained, and their associated factors were further assessed using multivariable linear regression.

RESULTS

A total of 184,363 TKAs were included. The LOS decreased from 10.8 days in 2013 to 9.3 days in 2019. The admission-to-surgery interval decreased from 4.6 to 4.2 days. The mean inpatient charges were 61,208.3 Chinese Yuan. Inpatient charges reached a peak in 2016, after which a gradual decrease was observed. Implant and material charges accounted for a dominating percentage, but they exhibited a downward trend, whereas labor-related charges gradually increased. Single marital status, non-osteoarthritis indication, and comorbidity were associated with longer LOS and higher inpatient charges. Female sex and younger age were associated with higher inpatient charges. There were apparent varieties of LOS and inpatient charges among provincial or non-provincial hospitals, hospitals with various TKA volume, or in different geographic regions.

CONCLUSIONS

The LOS following TKA in China appeared to be long, but it was shortened during the time period of 2013 to 2019. The inpatient charges dominated by implant and material charges exhibited a downward trend. However, there were apparent sociodemographic and hospital-related discrepancies of resource utilization. The observed statistics can lead to more efficient resource utilization of TKA in China.

Rural-urban differences in characteristics, postoperative outcomes, and costs for patients undergoing knee arthroplasty: a national retrospective propensity score matched cohort study

BACKGROUND

The rural-urban disparities in postoperative complications and costs among patients undergoing knee arthroplasty (KA) have not been thoroughly explored. This study aimed to determine whether such differences exist in this patient population.

MATERIAL AND METHODS

The study was conducted using data from the national Hospital Quality Monitoring System of China. Hospitalized patients undergoing KA from 2013 to 2019 were enrolled. Patient and hospital characteristics were compared between rural and urban patients, and differences in postoperative complications, readmissions, and hospitalization costs were analyzed using propensity score matching.

RESULTS

Of the 146 877 KA cases analyzed, 71.4% (104 920) were urban patients and 28.6% (41 957) were rural patients. Rural patients tended to be younger (64.4±7.7 years vs. 68.0±8.0 years; P <0.001) and had fewer comorbidities. In the matched cohort of 36 482 participants per group, rural patients were found to be more likely to experience deep vein thrombosis (OR: 1.31, 95% CI: 1.17-1.46; P <0.001) and require red blood cell (RBC) transfusion (OR: 1.38, 95% CI: 1.31-1.46; P <0.001). However, they had a lower incidence of readmission within 30 days (OR: 0.65, 95% CI: 0.59-0.72; P <0.001) and readmission within 90 days (OR: 0.61, 95% CI: 0.57-0.66; P <0.001) than their urban counterparts. In addition, rural patients incurred lower hospitalization costs than urban patients (57 396.2 Chinese Yuan vs. 60 844.3 Chinese Yuan; P <0.001).

CONCLUSION

Rural KA patients had different clinical characteristics compared with urban patients. While they had a higher likelihood of deep vein thrombosis and RBC transfusion following KA than urban patients, they had fewer readmissions and lower hospitalization costs. Targeted clinical management strategies are needed for rural patients.

Neuraxial versus general anesthesia for perioperative outcomes and resource utilization following knee arthroplasty: experience from a large national database

INTRODUCTION

Attentions have been paid to the optimal anesthesia for knee arthroplasty (KA). We sought to investigate whether neuraxial anesthesia (NA) is superior to general anesthesia (GA) in terms of perioperative outcomes and resource utilization following KA.

METHODS

Patients undergoing primary KA registered in the Hospital Quality Monitoring System (HQMS) in China during 2013-2019 were identified. By utilizing a time-stratified propensity score matching, every patient receiving NA was matched by propensity score to a patient receiving GA. Then, we conducted Poisson, logistic, and linear regression to compare NA with GA in terms of perioperative outcomes and resource utilization.

RESULTS

Of 109,132 included participants, 75,945 (69.59%) underwent KA with GA and 33,187 (30.41%) with NA. After propensity score matching (26,425 participants per group), NA was associated with lower incidence of blood transfusion (OR: 0.82, 95% CI 0.77-0.87; p < 0.0001), 30-day readmission (OR: 0.76, 95% CI 0.68-0.84; p < 0.0001), and 90-day readmission (OR: 0.83, 95% CI 0.77-0.90; p < 0.0001). No statistically significant difference in in-hospital mortality, incidence of pulmonary embolism, deep vein thrombosis, and surgical site infection was found. In addition, NA was associated with a 1% decrease in length of stay (95% CI 0-2%; p = 0.0070) and a 3% lower total hospital charge (95% CI 2-4%; p < 0.0001) when compared with GA.

CONCLUSION

Compared with GA, NA was associated with decreased incidence of blood transfusion, readmission, reduced length of stay, and total hospital charge following KA, suggesting the favorable role of NA for perioperative outcomes and resource utilization in KA.

Understanding the Influence of Hospital Volume on Inpatient Outcomes Following Hospitalization for Status Epilepticus

BACKGROUND

Prior studies show hospital admission volume to be associated with poor outcomes following elective procedures and inpatient medical hospitalizations. However, it is unknown whether hospital volume impacts Inpatient outcomes for status epilepticus (SE) hospitalizations. In this study, we aimed to assess the impact of hospital volume on the outcome of patients with SE and related inpatient medical complications.

METHODS

The 2005 to 2013 National Inpatient Sample database was queried using International Classification of Diseases 9th Edition diagnosis code 345.3 to identify patients undergoing acute hospitalization for SE. The National Inpatient Sample hospital identifier was used as a unique facility identifier to calculate the average volume of patients with SE seen in a year. The study cohort was divided into three groups: low volume (0-7 patients with SE per year), medium volume (8-22 patients with SE per year), and high volume (> 22 patients with SE per year). Multivariate logistic regression analyses were used to assess whether medium or high hospital volume had lower rates of inpatient medical complications compared with low-volume hospitals.

RESULTS

A total of 137,410 patients with SE were included in the analysis. Most patients (n = 50,939; 37%) were treated in a low-volume hospital, 31% (n = 42,724) were treated in a medium-volume facility, and 18% (n = 25,207) were treated in a high-volume hospital. Patients undergoing treatment at medium-volume hospitals (vs. low-volume hospitals) had higher odds of pulmonary complications (odds ratio [OR] 1.18 [95% confidence interval {CI} 1.12-1.25]; p < 0.001), sepsis (OR 1.24 [95% CI 1.08-1.43] p = 0.002), and length of stay (OR 1.13 [95% CI 1.0 -1.19] p < 0.001). High-volume hospitals had significantly higher odds of urinary tract infections (OR 1.21 [95% CI 1.11-1.33] p < 0.001), pulmonary complications (OR 1.19 [95% CI 1.10-1.28], p < 0.001), thrombosis (OR 2.13 [95% CI 1.44-3.14], p < 0.001), and renal complications (OR 1.21 [95% CI 1.07-1.37], p = 0.002). In addition, high-volume hospitals had lower odds of metabolic (OR 0.81 [95% CI 0.72-0.91], p < 0.001), neurological complications (OR 0.80 [95% CI 0.69-0.93], p = 0.004), and disposition to a facility (OR 0.89 [95% CI 0.82-0.96], p < 0.001) compared with lower-volume hospitals.

CONCLUSIONS

Our study demonstrates certain associations between hospital volume and outcomes for SE hospitalizations. Further studies using more granular data about the type, severity, and duration of SE and types of treatment are warranted to better understand how hospital volume may impact care and prognosis of patients.

Navigated intramedullary nailing for patients with intertrochanteric hip fractures is cost-effective at high-volume hospitals in mainland China: A markov decision analysis

Objective

Previous studies have reported that navigation systems can improve clinical outcomes of intramedullary nailing (IMN) for patients with intertrochanteric fractures. However, information is lacking regarding the relationship between the costs of navigated systems and clinical outcomes. The present research aimed to evaluate the cost-effectiveness of navigated IMN as compared with traditional freehand IMN for patients with intertrochanteric fractures.

Methods

A Markov decision model with a 5-year time horizon was constructed to investigate the costs, clinical outcomes and incremental cost-effectiveness ratio (ICER) of navigated IMN for a 70-year-old patient with an intertrochanteric fracture in mainland China. The costs [Chinese Yuan (¥)], health utilities (quality-adjusted life-years, QALYs) and transition probabilities were obtained from published studies. The willingness-to-pay threshold for ICER was set at ¥1,40,000/QALY following the Chinese gross domestic product in 2020. Three institutional surgical volumes were used to determine the average navigation-related costs per patient: low volume (100 cases), medium volume (200 cases) and high volume (300 cases).

Results

Institutes at which 300, 200 and 100 cases of navigated IMN were performed per year showed an ICER of ¥43,149/QALY, ¥76,132.5/QALY and ¥1,75,083/QALY, respectively. Navigated IMN would achieve cost-effectiveness at institutes with an annual volume of more than 125 cases.

Conclusions

Our analysis demonstrated that the navigated IMN could be cost-effective for patients with inter-trochanteric fracture as compared to traditional freehand IMN. However, the cost-effectiveness was more likely to be achieved at institutes with a higher surgical volume.

Socioeconomic factors affecting outcomes in total knee and hip arthroplasty: a systematic review on healthcare disparities

Background

Recent studies showed that healthcare disparities exist in use of and outcomes after total joint arthroplasty (TJA). This systematic review was designed to evaluate the currently available evidence regarding the effect socioeconomic factors, like income, insurance type, hospital volume, and geographic location, have on utilization of and outcomes after lower extremity arthroplasty.

Methods

A comprehensive search of the literature was performed by querying the MEDLINE database using keywords such as, but not limited to, “disparities”, “arthroplasty”, “income”, “insurance”, “outcomes”, and “hospital volume” in all possible combinations. Any study written in English and consisting of level of evidence I-IV published over the last 20 years was considered for inclusion. Quantitative and qualitative analyses were performed on the data.

Results

A total of 44 studies that met inclusion and quality criteria were included for analysis. Hospital volume is inversely correlated with complication rate after TJA. Insurance type may not be a surrogate for socioeconomic status and, instead, represent an independent prognosticator for outcomes after TJA. Patients in the lower-income brackets may have poorer access to TJA and higher readmission risk but have equivalent outcomes after TJA compared to patients in higher income brackets. Rural patients have higher utilization of TJA compared to urban patients.

Conclusion

This systematic review shows that insurance type, socioeconomic status, hospital volume, and geographic location can have significant impact on patients’ access to, utilization of, and outcomes after TJA.

Level of evidence

IV.

Supplementary Information

The online version contains supplementary material available at 10.1186/s42836-022-00137-4.

A nationwide comparison of staggered and simultaneous bilateral knee arthroplasty during a single hospitalization: Trends, risks and benefits

Background

We aimed to: (1) perform a nationwide trend analysis of staggered and simultaneous bilateral knee arthroplasty (KA); (2) investigate patient demographics and hospital characteristics in two groups; and (3) compare the outcomes of two groups with a focus on complications, length of stay (LOS) and hospitalization costs.

Methods

Utilizing the Hospital Quality Monitoring System, we included patients who underwent bilateral KA during a single hospitalization between 2013 and 2019. Patient demographics and hospital characteristics were compared between two groups. Outcomes were compared between propensity-score matched groups using logistic and linear regression.

Results

During the study period, 6291 staggered bilateral KA and 6284 simultaneous bilateral KA were performed. From 2013 to 2019, the proportion of staggered bilateral KA increased from 32.74% to 59.08%. Patients who were older, were single, had more comorbidities and had a non-osteoarthritis indication for surgery tended to receive staggered bilateral KA. Compared with 3327 propensity-score matched patients undergoing simultaneous bilateral KA, patients undergoing staggered bilateral KA were associated with a significantly lower incidence of wound infection (odds ratio [OR] ​= ​0.22; 95% confidence interval [CI], 0.07–0.65), and readmission within 30 days (OR ​= ​0.73; 95%CI, 0.54–0.99) and 90 days (OR ​= ​0.70; 95%CI, 0.55–0.89). However, staggered bilateral KA had higher odds of blood transfusion (OR ​= ​1.20; 95%CI, 1.02–1.40) and deep venous thrombosis (DVT) (OR ​= ​2.62; 95%CI, 1.82–3.98). Moreover, staggered bilateral KA can lead to higher costs (108,316.21 Chinese yuan [CNY] vs 103,367.60 CNY) and longer LOS (17.29 days vs 12.18 days) than simultaneous bilateral KA.

Conclusion

Our study indicates that staggered bilateral KA has become more common than simultaneous bilateral KA in China. Compared to simultaneous bilateral KA, staggered bilateral KA was associated with a lower incidence of wound infection and readmission. Staggered bilateral KA may be an alternative for patients who can't tolerate simultaneous surgery.

The translational potential of this article: Our study indicates that staggered bilateral KA is a safe and economical option for elderly patients who require bilateral KA but are at high clinical risk. The rising proportion of staggered bilateral KA will be a new trend in bilateral KA.

Effects of Hospital and Surgeon Volume on Patient Outcomes After Total Joint Arthroplasty: Reported From the American Joint Replacement Registry

BACKGROUND

The purpose of this study was to evaluate outcomes and complications because it relates to surgeon and hospital volume for patients undergoing primary total hip arthroplasty (THA) and total knee arthroplasty (TKA) using the American Joint Replacement Registry from 2012 to 2017.

METHODS

A retrospective study was conducted on Medicare-eligible cases of primary elective THAs and TKAs reported to the American Joint Replacement Registry database and was linked with the available Centers of Medicaid and Medicare Services claims and the National Death Index data from 2012 to 2017. Surgeon and hospital volume were defined separately based on the median annual number of anatomic-specific total arthroplasty procedures performed on patients of any age per surgeon and per hospital. Values were aggregated into separate surgeon and hospital volume tertile groupings and combined to create pairwise comparison surgeon/hospital volume groupings for hip and knee.

RESULTS

Adjusted multivariable logistic regression analysis found low surgeon/low hospital volume to have the greatest association with all-cause revisions after THA (odds ratio [OR], 1.63, 95% confidence interval [CI], 1.41-1.89, P < 0.0001) and TKA (OR, 1.72, 95% CI, 1.44-2.06, P < 0.0001), early revisions because of periprosthetic joint infection after THA (OR, 2.50, 95% CI, 1.53-3.15, P < 0.0001) and TKA (OR, 2.18, 95% CI, 1.64-2.89, P < 0.0001), risk of early THA instability and dislocation (OR, 2.47, 95% CI, 1.77-3.46, P < 0.0001), and 90-day mortality after THA (OR, 1.72, 95% CI, 1.27-2.35, P = 0.0005) and TKA (OR, 1.47, 95% CI, 1.15-1.86, P = 0.002).

CONCLUSION

Our findings demonstrate considerably greater THA and TKA complications when performed at low-volume hospitals by low-volume surgeons. Given the data from previous literature including this study, a continued push through healthcare policies and healthcare systems is warranted to direct THA and TKA procedures to high-volume centers by high-volume surgeons because of the evident decrease in complications and considerable costs associated with all-cause revisions, periprosthetic joint infection, instability, and 90-day mortality.

LEVEL OF EVIDENCE

III.

Surgeon and Facility Volume are Associated With Postoperative Complications After Total Knee Arthroplasty

Background

Surgeon and hospital volumes may affect outcomes of various orthopedic procedures. The purpose of this study is to characterize the volume dependence of both facilities and surgeons on morbidity and mortality after total knee arthroplasty.

Methods

Adults who underwent total knee arthroplasty for osteoarthritis from 2011 to 2015 were identified using International Classification of Diseases-9 Clinical Modification diagnostic and procedural codes in the New York Statewide Planning and Research Cooperative System database. Readmission, in-hospital mortality, and other adverse events were compared across surgeon and facility volumes using multivariable Cox proportional hazards regression, while controlling for patient demographic and clinical factors. Surgeon and facility volumes were compared between the lowest and highest 20%.

Results

Of 113,784 identified patients, 71,827 were treated at a high- or low-volume facility or by low- or high-volume surgeon. Low-volume facilities had higher 1-month, 3-month, and 12-month rates of readmission, urinary tract infection, cardiorespiratory arrest, surgical site infection, and wound complications; higher 3- and 12-month rates of pneumonia, cellulitis, and in-facility mortality; and higher 12-month rates of acute renal failure and revision. Low-volume surgeons had higher 1-, 3-, and 12-month rates of readmission, urinary tract infection, acute renal failure, pneumonia, surgical site infection, deep vein thrombosis, pulmonary embolism, cellulitis, and wound complications; higher 3- and 12-month rates of cardiorespiratory arrest; and higher 12-month rate of in-facility mortality.

Conclusions

These results suggest volume shifting toward higher volume facilities and/or surgeons could improve patient outcomes and have potential cost savings. Furthermore, these results can inform healthcare policy, for example, designating institutions as centers of excellence.

Hospital volume-outcome relationship in total knee arthroplasty: a systematic review and dose-response meta-analysis

PURPOSE

This systematic review and dose-response meta-analysis aimed to investigate the relationship between hospital volume and outcomes for total knee arthroplasty (TKA).

METHODS

MEDLINE, Embase, CENTRAL and CINAHL were searched up to February 2020 for randomised controlled trials and cohort studies that reported TKA performed in hospitals with at least two different volumes and any associated patient-relevant outcomes. The adjusted effect estimates (odds ratios, OR) were pooled using a random-effects, linear dose-response meta-analysis. Heterogeneity was quantified using the I²-statistic. ROBINS-I and the GRADE approach were used to assess the risk of bias and the confidence in the cumulative evidence, respectively.

RESULTS

A total of 68 cohort studies with data from 1985 to 2018 were included. The risk of bias for all outcomes ranged from moderate to critical. Higher hospital volume may be associated with a lower rate of early revision ≤ 12 months (narrative synthesis of k = 7 studies, n = 301,378 patients) and is likely associated with lower mortality ≤ 3 months (OR = 0.91 per additional 50 TKAs/year, 95% confidence interval [0.87-0.95], k = 9, n = 2,638,996, I² = 51%) and readmissions ≤ 3 months (OR = 0.98 [0.97-0.99], k = 3, n = 830,381, I² = 44%). Hospital volume may not be associated with the rates of deep infections within 1-4 years, late revision (1-10 years) or adverse events ≤ 3 months. The confidence in the cumulative evidence was moderate for mortality and readmission rates; low for early revision rates; and very low for deep infection, late revision and adverse event rates.

CONCLUSION

An inverse volume-outcome relationship probably exists for some TKA outcomes, including mortality and readmissions, and may exist for early revisions. Small reductions in unfavourable outcomes may be clinically relevant at the population level, supporting centralisation of TKA to high-volume hospitals.

LEVEL OF EVIDENCE

III.

REGISTRATION NUMBER

The study was registered in the International Prospective Register of Systematic Reviews (PROSPERO CRD42019131209 available at: https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=131209 ).