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

The Association Between Surgeon Volume and Dislocation After Total Hip Arthroplasty: A Nationwide Evaluation of 5,106 Orthopaedic Surgeons

INTRODUCTION

The relationship between surgeon volume and risk of dislocation after total hip arthroplasty (THA) is debated. This study sought to characterize this association and assess patient outcomes using a nationwide patient and surgeon registry.

METHODS

The Premier Healthcare Database was queried for adult primary elective THA patients from January 1, 2016, to December 31, 2019. Annual surgeon volume and 90-day risk of dislocation were modeled using multivariable logistic regression with restricted cubic splines. Bootstrap analysis identified a threshold annual case volume, corresponding to the maximum decrease in dislocation risk. Surgeons with an annual volume greater than the threshold were deemed high volume, and those with an annual volume less than the threshold were low volume. Each surgeon within a given year was treated as a unique entity (surgeon-year unit). 90-day complications of patients treated by high-volume and low-volume surgeons were compared.

RESULTS

From 2016 to 2019, 352,131 THAs were performed by 5,106 surgeons. The restricted cubic spline model demonstrated an inverse relationship between risk of dislocation and surgeon volume (threshold: 109 cases per year). A total of 9,967 (87.8%) low-volume surgeon-year units had individual dislocation rates lower than the average of the entire surgeon cohort. Patients treated by high-volume surgeons had decreased risk of dislocation (adjusted odds ratio [aOR], 0.60; 95% CI, 0.54 to 0.67), periprosthetic fracture (aOR, 0.87; 95% CI, 0.76 to 0.99), periprosthetic joint infection (aOR, 0.63; 95% CI, 0.56 to 0.69), readmission (aOR, 0.70; 95% CI, 0.67 to 0.73), and in-hospital death (aOR, 0.60; 95% CI, 0.46 to 0.80).

CONCLUSION

While most of the low-volume surgeons had dislocation rates lower than the cohort average, increasing annual surgeon case volume was associated with a reduction in risk of dislocation after primary elective THA.

THERAPEUTIC LEVEL OF EVIDENCE

Level IV.

Individualized Surgeon Reports in a Statewide Registry: A Pathway to Improved Outcomes

ABSTRACT

Despite progress with the development of joint replacement registries in the United States, surgeons may have limited opportunities to determine the cumulative outcome of their own patients or understand how those outcomes compare with their peers; this information is important for quality improvement. In order to provide surgeons with accurate data, it is first necessary to have a registry with complete coverage and patient matching. Some international registries have accomplished this. Building on a comprehensive statewide registry in the United States, a surgeon-specific report has been developed to provide surgeons with survivorship and complication data, which allows comparisons with other surgeons in the state. This article describes funnel plots, cumulative sum reports, complication-specific data, and patient-reported outcome measure data, which are provided to hip and knee arthroplasty surgeons with the goal of improving quality, decreasing variability in the delivery of care, and leading to improved value and outcomes for hip and knee arthroplasty in the state of Michigan.

Does the placement of acetabular cups differ between right and left sides for a right-handed surgeon operating through a direct lateral approach? A comparative study

PURPOSE

Although many factors were suggested to affect acetabular cup positioning during primary total hip arthroplasty, the effect of surgeon handedness was rarely evaluated. We aimed primarily to assess the difference in cup positioning (inclination and anteversion) between the right and left sides during primary THA. Secondly, to check the difference in the percentages of cups positioned in the safe zone for inclination and anteversion and if there will be a difference in cup positioning according to the type of cup fixation (cemented vs. cementless).

METHODS

Cup inclination and anteversion of 420 THAs were radiographically evaluated retrospectively. THAs were performed by a senior right-handed surgeon, who operated through a direct lateral approach in a lateral decubitus position using manual instruments and freehand technique for cup placement. Patients were assigned to two groups: Group A (right, or dominant side), and Group B (left, or non-dominant side), with equal cases of THAs (n = 210) in each group.

RESULTS

No difference was found in patients' basic characteristics, preoperative diagnosis, and cup fixation (54.3% cemented and 45.7% cementless) between the two groups. There was a significant difference in cup inclination between Groups A and Group B (40.1° ± 6.3° vs. 38.2° ± 6.1°) (P = 0.002). No significant difference was revealed in anteversion between the two groups (11.7° ± 4.4° vs. 11.8° ± 4.7°) (P = 0.95). The percentage of cups located within the safe zone in terms of both inclination and anteversion was 85.2% vs. 83.8% and 69% vs. 73.3% for Group A and Group B, according to Lewinnek and Callahan's safe zones, respectively. There existed a significant difference in the cemented cup inclination between Group A and Group B (40.8° ± 6.4° vs. 38.3° ± 6.3°) (P = 0.004).

CONCLUSION

Cup inclination is affected by the surgeon's handedness when operating through a direct lateral approach and using a freehand technique, while anteversion is less affected. Furthermore, the difference is greater with cemented cups.

Inpatient Hospital Costs, Emergency Department Visits, and Readmissions for Revision Hip and Knee Arthroplasty

BACKGROUND

Revision total hip arthroplasty (THA) and total knee arthroplasty (TKA) tremendously burden hospital resources. This study evaluated factors influencing perioperative costs, including emergency department (ED) visits, readmissions, and total costs-of-care within 90 days following revision surgery.

METHODS

A retrospective analysis of 772 revision TKAs and THAs performed on 630 subjects at a single center between January 2007 and December 2019 was conducted. Cost data were available from January 2015 to December 2019 for 277 patients. Factors examined included comorbidities, demographic information, preoperative Anesthesia Society of Anesthesiologists score, implant selection, and operative indication using mixed-effects linear regression models.

RESULTS

Among 772 revisions (425 THAs and 347 TKAs), 213 patients required an ED visit, and 90 required hospital readmission within 90 days. There were 22.6% of patients who underwent a second procedure after their initial revision. Liver disease was a significant predictor of ED readmission for THA patients (multivariable odds ratio [OR]: 3.473, P = .001), while aseptic loosening, osteolysis, or instability significantly reduced the odds of readmission for TKA patients (OR: 0.368, P = .014). In terms of ED visits, liver disease increased the odds for THA patients (OR: 1.845, P = .100), and aseptic loosening, osteolysis, or instability decreased the odds for TKA patients (OR: 0.223, P < .001). Increased age was associated with increased costs in both THA and TKA patients, with significant cost factors including congestive heart failure for TKA patients (OR: $7,308.17, P = .004) and kidney disease for THA patients. Revision surgeries took longer than primary ones, with TKA averaging 3.0 hours (1.6 times longer) and THA 2.8 hours (1.5 times longer).

CONCLUSIONS

Liver disease increases ED readmission risk in revision THA, while aseptic loosening, osteolysis, or instability decreases it in revision TKA. Increased age and congestive heart failure are associated with increased costs. These findings inform postoperative care and resource allocation in revision arthroplasty.

LEVEL OF EVIDENCE

Economic and Decision Analysis, Level IV.

Surgical stabilization of rib fractures: The impact of volume and the need for standardized indications

INTRODUCTION

We aimed to examine impact of trauma center (TC) surgical stabilization of rib fracture (SSRF) volume on outcomes of patients undergoing SSRF.

METHODS

Blunt rib fracture patients who underwent SSRF were included from ACS-TQIP2017-2021. TCs were stratified according to tertiles of SSRF volume:low (LV), middle, and high (HV). Outcomes were time to SSRF, respiratory complications, prolonged ventilator use, mortality.

RESULTS

16,872 patients were identified (LV:5470,HV:5836). Mean age was 56 years, 74% were male, median thorax-AIS was 3. HV centers had a lower proportion of patients with flail chest (HV41% vs LV50%), pulmonary contusion (HV44% vs LV52%) and had shorter time to SSRF(HV58 vs LV76 ​h), less respiratory complications (HV3.2% vs LV4.5%), prolonged ventilator use (HV15% vs LV26%), mortality (HV2% vs LV2.6%) (all p ​< ​0.05). On multivariable regression analysis, HV centers were independently associated with reduced time to SSRF(β ​= ​-18.77,95%CI ​= ​-21.30to-16.25), respiratory complications (OR ​= ​0.67,95%CI ​= ​0.49-0.94), prolonged ventilator use (OR ​= ​0.49,95%CI ​= ​0.41-0.59), but not mortality.

CONCLUSIONS

HV SSRF centers have improved outcomes, however, there are variations in threshold for SSRF and indications must be standardized.

LEVEL OF EVIDENCE

Level III.

STUDY TYPE

Therapeutic/Care Management.

Higher odds of meniscectomy compared with meniscus repair in a young patient population with increased neighbourhood disadvantage

OBJECTIVES

To investigate the impact of demographic and socioeconomic factors on the management of isolated meniscus tears in young patients and to identify trends in surgical management of meniscus tears based on surgeon volume.

METHODS

Data from a large healthcare system on patients aged 14-44 years who underwent isolated meniscus surgery between 2016 and 2022 were analysed. Patient demographics, socioeconomic factors and surgeon volume were recorded. Patient age was categorised as 14-29 years and 30-44 years old. Area Deprivation Index (ADI), a measure of neighbourhood disadvantage with increased ADI corresponding to more disadvantage, was grouped as <25th, 25-75th and >75th percentile. Multivariate comparisons were made between procedure groups while univariate comparisons were made between surgeon groups.

RESULTS

The study included 1552 patients treated by 84 orthopaedic surgeons. Older age and higher ADI were associated with higher odds of undergoing meniscectomy. Patients of older age and with non-private insurance were more likely to undergo treatment by a lower-volume knee surgeon. Apart from the year 2022, higher-volume knee surgeons performed significantly higher rates of meniscus repair compared with lower-volume knee surgeons. When controlling for surgeon volume, higher ADI remained a significant predictor of undergoing meniscectomy over meniscus repair.

CONCLUSION

Significant associations exist between patient factors and surgical choices for isolated meniscus tears in younger patients. Patients of older age and with increased neighbourhood disadvantage were more likely to undergo meniscectomy versus meniscus repair. While higher-volume knee surgeons favoured meniscus repair, a growing trend of meniscus repair rates was observed among lower-volume knee surgeons.

LEVEL OF EVIDENCE

Retrospective cohort study, level III.

Satisfactory 5-year functional outcomes following primary ACL reconstructions from the UK National Ligament Registry

PURPOSE

The aim of this study was to describe the 10-year findings from the UK National Ligament Registry (NLR).

METHODS

A retrospective review was performed for prospectively collected data on the NLR between January 2013 and December 2022. All patients who underwent primary ACL reconstruction (ACLR) on the registry were included. Surgical characteristics were analysed, including surgeon grade and case volume, concomitant knee procedures, venous thromboembolic prophylaxis, graft characteristics, femoral and tibial tunnel drilling, and fixation methods. Clinical outcomes were collected preoperatively and at 6 months, 1 year, 2 years and 5 years following the index procedure.

RESULTS

During the study period, 17,492 unilateral ACLR procedures were recorded. Autograft was used in 98%, most commonly a combined semitendinosus and gracilis graft (77%) or patella tendon graft (31%). Allograft was used in only 1% of the patients. In 52% of cases, ACLR was associated with an additional procedure, with isolated medial meniscal surgery being the most common (21%). Femoral tunnel drilling was mostly performed through an anteromedial portal (73%) and tibial tunnel drilling using an outside-in technique (92%). The most common method of femoral graft fixation was with an Endobutton fixed loop suspensory device (77%), while interference screws predominated for tibial tunnel fixation (86%). Patients who underwent ACLR surgery showed significant improvement in their functional outcome scores at six months, 1 year, 2 years and 5 years postoperatively.

CONCLUSION

Data from the NLR shows a detailed description of the current trends and evolution of ACLR in the United Kingdom over the last 10 years. Satisfactory functional outcomes were observed 5 years postoperatively. This study provides useful information on the prevalence of ACL-associated injuries and current surgical techniques with the aim of improving the quality of clinical care and patients' outcomes. Moreover, it provides surgeons with a benchmark against which to compare current practices and functional outcomes following ACLR across the United Kingdom.

LEVEL OF EVIDENCE

Level III.

Tranexamic Acid and Tourniquet: Which Combination Reduces Blood Loss Most Effectively?

BACKGROUND

Blood loss during and after total knee arthroplasty (TKA) can lead to substantial morbidity and the need for blood transfusions. There are several methods to minimize blood loss and decrease transfusion rates in patients undergoing TKA. Tranexamic acid, an antifibrinolytic agent with known efficacy for achieving these goals, is combined with tourniquets to reduce bleeding in arthroplasty surgeries. Our study investigated the effects of various combinations of tranexamic acid and tourniquet use on bleeding in knee arthroplasty in 558 patients.

AIM

We aimed to determine the method that would provide the least blood loss and transfusion need in knee arthroplasty surgery.

METHODS

Between January 2018 and December 2022, 558 patients aged between 55 and 85 years underwent TKA surgery for grade 4 gonarthrosis in our clinic, and their decrease in hemoglobin value and whether they were transfused or not were analyzed. The patients were divided into four groups based on use of tranexamic acid and tourniquet. Demographic variables and patient data (body mass index, INR values, and preoperative hemoglobin values) were recorded.

RESULTS

There were 558 patients with a mean age of 68.19 (67 ± 6.949) years. In group 1, tranexamic acid was not used in 128 patients and tourniquet was used only during cementation; in group 2, in 132 patients, tranexamic acid was not used and tourniquet was used throughout the surgery; in group 3, in 158 patients, tranexamic acid was used and tourniquet was used throughout the surgery; in group 4, in 140 patients, tranexamic acid was used and tourniquet was used only during cementation. The decrease in hemoglobin value and transfusion rate was lowest in group 3 and highest in group 1. Besides, there was a greater decrease in hemoglobin value in group 2 than in group 4 and the transfusion rate was similar.

CONCLUSIONS

This clinical study showed that using tranexamic acid and a tourniquet throughout surgery significantly reduced the decrease in hemoglobin value and the need for transfusion.

Most Military Arthroplasty Surgeons Have a Low Volume Practice in the Military Health System

Background

The purpose of this study is to investigate hospital and surgeon joint arthroplasty volume in the Military Health System (MHS). A secondary aim is to look at interruption in physician practice during the study period.

Methods

Review of all patients undergoing hip or knee arthroplasty in the MHS over >5-year period to examine hospital and surgeon volume for total joint arthroplasty (TJA). We stratified hospital and surgeon volume into low, medium, and high volumes.

Results

Fifty surgeons performed at least 50 hip and/or knee arthroplasties during this period. These surgeons accounted for 75% of TJA in the MHS. When stratified by cases per year, the median primary total hip arthroplasty (THA) per year was 31.4 and primary total knee arthroplasty (TKA) was 47.3 per year. Regarding the volume threshold for primary and revision TJA, all hospitals were classified as having low volumes for both THA and unicompartmental knee arthroplasty/TKA. There were 0 high volume, 7 (21.9%) medium volume, and 25 (78.1%) low volume THA surgeons; there was 1 high volume TKA surgeon, 17 (34.7%) medium volume, and 31 (63.3%) low volume TKA surgeons. The average duration of clinical activity for fellowship-trained surgeons over the study period was 4.0 years, and the average duration of clinical inactivity was 263.7 days (17.9% of practice period).

Conclusions

The highest-volume military arthroplasty surgeons have low volume when compared to their civilian colleagues. There are also long periods of clinical practice interruption. These findings stress the need to establish civilian-DOD or DOD-VA working relationships so that MHS patients experience the best possible care by high-volume surgeons in high-volume surgical centers.

Medullary-Sparing Antibiotic Cement Articulating Spacer Reduces the Rate of Mechanical Complications in Advanced Septic Hip Arthritis: A Retrospective Cohort Study

Antibiotic cement articulating spacers eradicate infection during a two-stage revision for advanced septic hip arthritis (ASHA); however, mechanical complications have been reported. We hypothesized that the rate of mechanical complications would be lower in medullary-sparing (MS) than in non-medullary-sparing (n-MS) articulating spacers. A retrospective study of ASHA using n-MS or MS spacers was conducted between 1999 and 2019. The rate of mechanical complications and reoperation and risk factors for mechanical complications were analyzed. The cohort included 71 n-MS and 36 MS spacers. All patients were followed up for 2 years. The rate of spacer dislocation was lower in MS (0%) than in n-MS spacers (14.1%; p = 0.014). The reoperation rate for mechanical complications was lower in MS (0%) than in n-MS spacers (12.7%; p = 0.019). The rate of a diaphyseal stem during reimplantation was lower in MS (0%) than in n-MS spacers (19.4%; p = 0.002). The identified risk factors for n-MS spacer dislocation were postoperative under-restored femoral head diameter ≥3 mm, femoral offset ≥3 mm, and surgical volume (≤6 resection arthroplasties per year). Both spacers controlled infection. However, MS spacers had a lower spacer dislocation and reoperation rate and avoided the diaphyseal stem during reimplantation. We recommend using MS spacers to restore native femoral head diameter and femoral offset when ASHA is treated by surgeons with lower surgical volumes.

Do the Revision Rates of Arthroplasty Surgeons Correlate With Postoperative Patient-reported Outcome Measure Scores? A Study From the Australian Orthopaedic Association National Joint Replacement Registry

BACKGROUND

Patient-reported outcome measures (PROMs) are a pragmatic and efficient means to evaluate the functional quality of arthroplasty beyond revision rates, which are used by most joint replacement registries to judge success. The relationship between these two measures of quality-revision rates and PROMs-is unknown, and not every procedure with a poor functional result is revised. It is logical-although still untested-that higher cumulative revision rates correlate inversely with PROMs for individual surgeons; more revisions are associated with lower PROM scores.

QUESTIONS/PURPOSES

We used data from a large national joint replacement registry to ask: (1) Does a surgeon's early THA cumulative percent revision (CPR) rate and (2) early TKA CPR rate correlate with the postoperative PROMs of patients undergoing primary THA and TKA, respectively, who have not undergone revision?

METHODS

Elective primary THA and TKA procedures in patients with a primary diagnosis of osteoarthritis that were performed between August 2018 and December 2020 and registered in the Australian Orthopaedic Association National Joint Replacement Registry PROMs program were eligible. THAs and TKAs were eligible for inclusion in the primary analysis if 6-month postoperative PROMs were available, the operating surgeon was clearly identified, and the surgeon had performed at least 50 primary THAs or TKAs. Based on the inclusion criteria, 17,668 THAs were performed at eligible sites. We excluded 8878 procedures that were not matched to the PROMs program, leaving 8790 procedures. A further 790 were excluded because they were performed by unknown or ineligible surgeons or were revised, leaving 8000 procedures performed by 235 eligible surgeons, including 4256 (53%; 3744 cases of missing data) patients who had postoperative Oxford Hip Scores and 4242 (53%; 3758 cases of missing data) patients who had a postoperative EQ-VAS score recorded. Complete covariate data were available for 3939 procedures for the Oxford Hip Score and for 3941 procedures for the EQ-VAS. A total of 26,624 TKAs were performed at eligible sites. We excluded 12,685 procedures that were not matched to the PROMs program, leaving 13,939 procedures. A further 920 were excluded because they were performed by unknown or ineligible surgeons, or because they were revisions, leaving 13,019 procedures performed by 276 eligible surgeons, including 6730 (52%; 6289 cases of missing data) patients who had had postoperative Oxford Knee Scores and 6728 (52%; 6291 cases of missing data) patients who had a postoperative EQ-VAS score recorded. Complete covariate data were available for 6228 procedures for the Oxford Knee Score and for 6241 procedures for the EQ-VAS. The Spearman correlation between the operating surgeon's 2-year CPR and 6-month postoperative EQ-VAS Health and Oxford Hip or Oxford Knee Score was evaluated for THA and TKA procedures where a revision had not been performed. Associations between postoperative Oxford and EQ-VAS scores and a surgeon's 2-year CPR were estimated based on multivariate Tobit regressions and a cumulative link model with a probit link, adjusting for patient age, gender, ASA score, BMI category, preoperative PROMs, as well as surgical approach for THA. Missing data were accounted for using multiple imputation, with models assuming they were missing at random and a worst-case scenario.

RESULTS

Of the eligible THA procedures, postoperative Oxford Hip Score and surgeon 2-year CPR were correlated so weakly as to be clinically irrelevant (Spearman correlation ρ = -0.09; p < 0.001), and the correlation with postoperative EQ-VAS was close to zero (ρ = -0.02; p = 0.25). Of the eligible TKA procedures, postoperative Oxford Knee Score and EQ-VAS and surgeon 2-year CPR were correlated so weakly as to be clinically irrelevant (ρ = -0.04; p = 0.004 and ρ = 0.03; p = 0.006, respectively). All models accounting for missing data found the same result.

CONCLUSION

A surgeon's 2-year CPR did not exhibit a clinically relevant correlation with PROMs after THA or TKA, and all surgeons had similar postoperative Oxford scores. PROMs, revision rates, or both may be inaccurate or imperfect indicators of successful arthroplasty. Missing data may limit the findings of this study, although the results were consistent under a variety of different missing data scenarios. Innumerable factors contribute to arthroplasty results, including patient-related variables, differences in implant design, and the technical quality of the procedure. PROMs and revision rates may be analyzing two different facets of function after arthroplasty. Although surgeon variables are associated with revision rates, patient factors may exert a stronger influence on functional outcomes. Future research should identify variables that correlate with functional outcome. Additionally, given the gross level of function that Oxford scores record, outcome measures that can identify clinically meaningful functional differences are required. The use of Oxford scores in national arthroplasty registries may rightfully be questioned.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Social Determinants of Health Disparities Increase the Rate of Complications After Total Knee Arthroplasty

BACKGROUND

Few studies have investigated whether social determinants of health disparities (SDHD), which include economic, social, education, health care, and environmental factors, identified through International Classification of Diseases (ICD) codes are associated with increased odds for poor health outcomes. We aimed to investigate the association between SDHD, identified through this novel methodology, as well as postoperative complications following total knee arthroplasty (TKA).

METHODS

Using a national insurance claims database, a retrospective cohort analysis was performed. Patients were selected using Current Procedural Terminology and ICD codes for primary TKA between 2010 and 2019. Patients were stratified into 2 groups using ICD codes, those who had SDHD and those who did not, and propensity matched 1:1 for age, sex, a comorbidity score, and other comorbidities. After matching, 207,844 patients were included, with 103,922 patients in each cohort. Odds ratios (ORs) for 90-day medical and 2-year surgical complications were obtained using multivariable logistical regressions.

RESULTS

In patients who have SDHD, multivariable analysis demonstrated higher odds of readmission (OR): 1.12; P = .013) and major and minor medical complications (OR: 2.09; P < .001) within 90-days as well as higher odds of revision surgery (OR: 1.77; P < .001) and periprosthetic joint infection (OR: 1.30; P < .001) within 2-years.

CONCLUSION

The SDHD are an independent risk factor for revision surgery and periprosthetic joint infection after TKA. In addition, SDHD is also an independent risk factor for all-cause hospital readmissions and both minor and major complications.

LEVEL OF EVIDENCE

III.

Increased 90-Day Readmissions and Complications Following Hip Arthroscopy in Centers With Low Surgical Volume in New York State

PURPOSE

To (1) classify surgical centers in New York State by volume of hip arthroscopies performed, (2) calculate rates of readmissions and complications by center volume, and (3) identify socioeconomic predictive factors for readmissions and complications following hip arthroscopy.

METHODS

Patients who underwent hip arthroscopy at New York State health care facilities from 2010 to 2020 were retrospectively identified using the New York Statewide Planning and Research Cooperative System (SPARCS) database. Hip arthroscopic procedures were identified using the following Current Procedural Terminology codes. Surgical center volumes were classified into 3 categories: low (<85th percentile), medium (85th-95th percentile), and high (>95th percentile). Incidence of readmissions and complications within 90 days was abstracted from SPARCS. Neighborhood socioeconomic status was quantified using the U.S. Area Deprivation Index. Multivariable logistic regression was used to determine whether center volume and other socioeconomic variables were independent predictors of outcomes.

RESULTS

In total, 50,252 patients who underwent hip arthroscopy were identified in SPARCS from 2010 to 2020. Of these patients, 13,861 (27.6%) underwent surgery at low-volume centers, 11,757 (23.4%) at medium-volume centers, and 24,634 (49.0%) at high-volume centers. Minorities, publicly insured patients, and patients from lower socioeconomic status neighborhoods made up a larger proportion of cases seen by low-volume centers versus high-volume centers (P < .001). Patients in the low-volume group experienced significantly greater 90-day rates of readmissions (P < .001) and all-cause complications (P < .001) than the other groups. Furthermore, high-volume centers were independently associated with lower odds of readmission (odds ratio 0.57, P < .001) and all-cause complications (odds ratio 0.73, P < .001) versus low-volume centers.

CONCLUSIONS

Low-volume surgical centers are associated with increased readmission and complication rates following hip arthroscopy, independent of other socioeconomic factors such as age, sex, race, insurance status, and neighborhood socioeconomic status.

LEVEL OF EVIDENCE

Level III, retrospective comparative prognostic trial.

Direct Anterior Versus Posterior Approach for Total Hip Arthroplasty Performed for Displaced Femoral Neck Fractures

OBJECTIVES

To compare perioperative, 90-day, and 1-year postoperative complications and outcomes between the direct anterior approach (DAA) and the posterior approach for total hip arthroplasty in geriatric patients with displaced femoral neck fractures (FNFs).

DESIGN

Retrospective cohort study.

SETTING

Multicenter Health care Consortium.

PATIENTS

Seven-hundred and nine patients 60 years or older with acute displaced FNFs between 2009 and 2021.

INTERVENTION

Total hip arthroplasty using either DAA or posterior approach.

MAIN OUTCOME MEASUREMENTS

Rates of postoperative complications including dislocations, reoperations, and mortality at 90 days and 1 year postoperatively. Secondary outcome measures included ambulation capacity at discharge, ambulation distance with inpatient physical therapy, discharge disposition, and narcotic prescription quantities (morphine milligram equivalents).

RESULTS

Through a multivariable regression analysis, DAA was associated with significantly shorter operative time ( B = -6.89 minutes; 95% confidence interval [CI] -12.84 to -0.93; P = 0.024), lower likelihood of blood transfusion during the index hospital stay (adjusted odds ratios = 0.54; 95% CI 0.27 to 0.96; P = 0.045), and decreased average narcotic prescription amounts at 90 days (B = -230.45 morphine milligram equivalents; 95% CI -440.24 to -78.66; P = 0.035) postoperatively. There were no significant differences in medical complications, dislocations, reoperations, and mortality at 90 days and 1 year postoperatively.

CONCLUSION

When comparing the DAA versus posterior approach for total hip arthroplasty performed for displaced FNF, DAA was associated with shorter operative time, lower likelihood of blood transfusion, and lower 90-day postoperative narcotic prescription amounts.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Postoperative Outcomes in Total Hip and Total Knee Arthroplasty for Patients Who Have Multiple Myeloma

BACKGROUND

Advancements in oncologic care have increased the longevity of patients who have multiple myeloma, although outcomes beyond the early postoperative period following total hip arthroplasty (THA) and total knee arthroplasty (TKA) remain unknown. This study investigated the influence of preoperative factors on implant survivorship following THA and TKA after a minimum 1-year interval for multiple myeloma patients.

METHODS

Using our institutional database, we identified 104 patients (78 THAs, 26 TKAs) from 2000 to 2021 diagnosed with multiple myeloma before their index arthroplasty by International Classification of Diseases, Ninth and Tenth Revisions (ICD-9 and ICD-10) codes 203.0× and C90.0× and corresponding Current Procedural Terminology (CPT) codes. Demographic data, oncologic treatments, and operative variables were collected. Multivariate logistic regressions assessed variables of interest, and Kaplan-Meier curves were used to estimate implant survival.

RESULTS

There were 9 (11.5%) patients who underwent revision THA after an average time of 1,312 days (range, 14 to 5,763), with infection (33.3%), periprosthetic fracture (22.2%), and instability (22.2%) being the most common indications. Of these patients, 3 (33.3%) underwent multiple revision surgeries. There was 1 (3.8%) patient who underwent revision TKA at 74 days postoperatively for infection. Patients treated with radiotherapy were more likely to require revision THA (odds Rratio (OR): 6.551, 95% confidence interval (CI): 1.148-53.365, P = .045), but no predictors of failure were identified for TKA patients.

CONCLUSION

Orthopaedic surgeons should know that multiple myeloma patients have a relatively high risk of revision, particularly following THA. Accordingly, patients who have risk factors for failure should be identified preoperatively to avoid poor outcomes.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Are Patient Outcomes Affected by Surgeon Experience With Total Hip Arthroplasty in Morbidly Obese Patients?

Background

Surgeons with high volume (HV) of total hip arthroplasty (THA) have seen better outcomes than low volume (LV) surgeons. However, literature regarding surgeon volume and outcomes in morbidly obese THA patients is scarce. This study examines the association between surgeon volume with THA in morbidly obese patients (body mass index ≥40) and their clinical outcomes.

Methods

We retrospectively reviewed all morbidly obese patients who underwent primary THA at our institution between March 2012 and July 2020 with 2 years of follow-up. Clinical outcomes were compared between the HV (HVa, top quartile of surgeons with the highest overall yearly THA volume) and LV (LVa) surgeons. Similar analysis was run comparing HV of morbidly obese THA (HVo, top quartile of surgeons with the highest yearly morbidly obese THA volume) and LV of morbidly obese THA (LVo) surgeons.

Results

Six hundred and forty-three patients and 33 surgeons were included. HVa surgeons had significantly shorter length of stay and increased home discharge. HVa and HVo surgeons had significantly shorter operative times. There were no significant differences in overall 90-day major and minor complications or clinical differences in patient-reported outcomes. Revision rates and freedom from revisions did not differ between groups at 2-year follow-up.

Conclusions

HVa surgeons had significantly lower length of stay and operative times and increased discharge to home. There was no significant decrease in complications or revisions in either comparison model. Complications, revision rates, and patient satisfaction in morbidly obese patients who undergo THA may be independent of surgeon volume.

Racial and Socioeconomic Disparities in Risk and Reason for Revision in Total Joint Arthroplasty

INTRODUCTION

Data regarding racial/ethnic and socioeconomic differences in revision total hip arthroplasty (rTHA) and revision total knee arthroplasty (rTKA) have been inconsistent. This study examined racial/ethnic and socioeconomic disparities in comorbidity-adjusted risk and reason for rTHA and rTKA.

METHODS

Patients who underwent rTHA or rTKA between 2006 and 2014 in the National Inpatient Sample were identified. Multivariable logistic regression models adjusted for payer status, hospital geographic setting, and patient characteristics (age, sex, and Elixhauser Comorbidity Index) were used to examine the effect of race/ethnicity and socioeconomic status on trends in annual risk of rTHA/rTKA and causes of rTHA/rTKA.

RESULTS

Black patients were less likely to undergo rTHA and more likely to undergo rTKA while Hispanic patients were more likely to undergo rTHA and less likely to undergo rTKA ( P < 0.001 for all) compared with White patients. Patients residing in areas of lower income quartiles were more likely to undergo rTHA and rTKA compared with those in the highest quartile ( P < 0.001), and these disparities persisted and widened over time. Black, Hispanic, and Asian patients were less likely to undergo rTHA/rTKA because of dislocation compared with White patients ( P < 0.001 for all). Patients from areas of lower income quartiles were more likely to undergo rTHA because of septic complications and less likely to require both rTHA and rTKA because of mechanical complications ( P < 0.001 for all).

DISCUSSION

Racial/ethnic and socioeconomic disparities exist in risk and cause of rTHA and rTKA. Increasing awareness and a focus on minimizing variability in hospital quality may help mitigate these disparities.

Machine Learning on Medicare Claims Poorly Predicts the Individual Risk of 30-Day Unplanned Readmission After Total Joint Arthroplasty, Yet Uncovers Interesting Population-level Associations With Annual Procedure Volumes

BACKGROUND

Unplanned hospital readmissions after total joint arthroplasty (TJA) represent potentially serious adverse events and remain a critical measure of hospital quality. Predicting the risk of readmission after TJA may provide patients and clinicians with valuable information for preoperative decision-making.

QUESTIONS/PURPOSES

(1) Can nonlinear machine-learning models integrating preoperatively available patient, surgeon, hospital, and county-level information predict 30-day unplanned hospital readmissions in a large cohort of nationwide Medicare beneficiaries undergoing TJA? (2) Which predictors are the most important in predicting 30-day unplanned hospital readmissions? (3) What specific information regarding population-level associations can we obtain from interpreting partial dependency plots (plots describing, given our modeling choice, the potentially nonlinear shape of associations between predictors and readmissions) of the most important predictors of 30-day readmission?

METHODS

National Medicare claims data (chosen because this database represents a large proportion of patients undergoing TJA annually) were analyzed for patients undergoing inpatient TJA between October 2016 and September 2018. A total of 679,041 TJAs (239,391 THAs [61.3% women, 91.9% White, 52.6% between 70 and 79 years old] and 439,650 TKAs [63.3% women, 90% White, 55.2% between 70 and 79 years old]) were included. Model features included demographics, county-level social determinants of health, prior-year (365-day) hospital and surgeon TJA procedure volumes, and clinical classification software-refined diagnosis and procedure categories summarizing each patient's Medicare claims 365 days before TJA. Machine-learning models, namely generalized additive models with pairwise interactions (prediction models consisting of both univariate predictions and pairwise interaction terms that allow for nonlinear effects), were trained and evaluated for predictive performance using area under the receiver operating characteristic (AUROC; 1.0 = perfect discrimination, 0.5 = no better than random chance) and precision-recall curves (AUPRC; equivalent to the average positive predictive value, which does not give credit for guessing "no readmission" when this is true most of the time, interpretable relative to the base rate of readmissions) on two holdout samples. All admissions (except the last 2 months' worth) were collected and split randomly 80%/20%. The training cohort was formed with the random 80% sample, which was downsampled (so it included all readmissions and a random, equal number of nonreadmissions). The random 20% sample served as the first test cohort ("random holdout"). The last 2 months of admissions (originally held aside) served as the second test cohort ("2-month holdout"). Finally, feature importances (the degree to which each variable contributed to the predictions) and partial dependency plots were investigated to answer the second and third research questions.

RESULTS

For the random holdout sample, model performance values in terms of AUROC and AUPRC were 0.65 and 0.087, respectively, for THA and 0.66 and 0.077, respectively, for TKA. For the 2-month holdout sample, these numbers were 0.66 and 0.087 and 0.65 and 0.075. Thus, our nonlinear models incorporating a wide variety of preoperative features from Medicare claims data could not well-predict the individual likelihood of readmissions (that is, the models performed poorly and are not appropriate for clinical use). The most predictive features (in terms of mean absolute scores) and their partial dependency graphs still confer information about population-level associations with increased risk of readmission, namely with older patient age, low prior 365-day surgeon and hospital TJA procedure volumes, being a man, patient history of cardiac diagnoses and lack of oncologic diagnoses, and higher county-level rates of hospitalizations for ambulatory-care sensitive conditions. Further inspection of partial dependency plots revealed nonlinear population-level associations specifically for surgeon and hospital procedure volumes. The readmission risk for THA and TKA decreased as surgeons performed more procedures in the prior 365 days, up to approximately 75 TJAs (odds ratio [OR] = 1.2 for TKA and 1.3 for THA), but no further risk reduction was observed for higher annual surgeon procedure volumes. For THA, the readmission risk decreased as hospitals performed more procedures, up to approximately 600 TJAs (OR = 1.2), but no further risk reduction was observed for higher annual hospital procedure volumes.

CONCLUSION

A large dataset of Medicare claims and machine learning were inadequate to provide a clinically useful individual prediction model for 30-day unplanned readmissions after TKA or THA, suggesting that other factors that are not routinely collected in claims databases are needed for predicting readmissions. Nonlinear population-level associations between low surgeon and hospital procedure volumes and increased readmission risk were identified, including specific volume thresholds above which the readmission risk no longer decreases, which may still be indirectly clinically useful in guiding policy as well as patient decision-making when selecting a hospital or surgeon for treatment.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Higher Surgeon Volume is Associated With a Lower Rate of Subsequent Revision Procedures After Total Shoulder Arthroplasty: A National Analysis

BACKGROUND

Studies assessing the relationship between surgeon volume and outcomes have shown mixed results, depending on the specific procedure analyzed. This volume relationship has not been well studied in patients undergoing total shoulder arthroplasty (TSA), but it should be, because this procedure is common, expensive, and potentially morbid.

QUESTIONS/PURPOSES

We performed this study to assess the association between increasing surgeon volume and decreasing rate of revision at 2 years for (1) anatomic TSA (aTSA) and (2) reverse TSA (rTSA) in the United States.

METHODS

In this retrospective study, we used Centers for Medicare and Medicaid Services (CMS) fee-for-service inpatient and outpatient data from 2015 to 2021 to study the association between annual surgeon aTSA and rTSA volume and 2-year revision shoulder procedures after the initial surgery. The CMS database was chosen for this study because it is a national sample and can be used to follow patients over time. We included patients with Diagnosis-related Group code 483 and Current Procedural Terminology code 23472 for TSA (these codes include both aTSA and rTSA). We used International Classification of Diseases, Tenth Revision, procedural codes. Patients who underwent shoulder arthroplasty for fracture (10% [17,524 of 173,242]) were excluded. We studied the variables associated with the subsequent procedure rate through a generalized linear model, controlling for confounders such as patient age, comorbidity risk score, surgeon and hospital volume, surgeon graduation year, hospital size and teaching status, assuming a binomial distribution with the dependent variable being whether an episode had at least one subsequent procedure within 2 years. The regression was fitted with standard errors clustered at the hospital level, combining all TSAs and within the aTSA and rTSA groups, respectively. Hospital and surgeon yearly volumes were calculated by including all TSAs, primary procedure and subsequent, during the study period. Other hospital-level and surgeon-level characteristics were obtained through public files from the CMS. The CMS Hierarchical Condition Category risk score was controlled because it is a measure reflecting the expected future health costs for each patient based on the patient's demographics and chronic illnesses. We then converted regression coefficients to the percentage change in the odds of having a subsequent procedure.

RESULTS

After controlling for confounding variables including patient age, comorbidity risk score, surgeon and hospital volume, surgeon graduation year, and hospital size and teaching status, we found that an annual surgeon volume of ≥ 10 aTSAs was associated with a 27% decreased odds of revision within 2 years (95% confidence interval 13% to 39%; p < 0.001), while surgeon volume of ≥ 29 aTSAs was associated with a 33% decreased odds of revision within 2 years (95% CI 18% to 45%; p < 0.001) compared with a volume of fewer than four aTSAs per year. Annual surgeon volume of ≥ 29 rTSAs was associated with a 26% decreased odds of revision within 2 years (95% CI 9% to 39%; p < 0.001).

CONCLUSION

Surgeons should consider modalities such as virtual planning software, templating, or enhanced surgeon training to aid lower-volume surgeons who perform aTSA and rTSA. More research is needed to assess the value of these modalities and their relationship with the rates of subsequent revision.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Timing and Factors Associated with Revision for Infection after Primary Total Knee Arthroplasty Based on American Joint Replacement Registry Data

BACKGROUND

Infection following total knee arthroplasty (TKA) remains a challenging clinical problem. Using American Joint Replacement Registry (AJRR) data, this study examined factors related to the incidence and timing of infection.

METHODS

Primary TKAs performed from January 2012 through December 2018 among patients ≥65 years of age at surgery were queried from AJRR and merged with Medicare data to enhance capture of revisions for infection. Multivariate Cox regressions incorporating patient, surgical, and institutional factors were used to produce hazard ratios (HR) associated with revision for infection and mortality after revision for infection.

RESULTS

Among 525,887 TKAs, 2,821 (0.54%) were revised for infection. Men had an increased risk of revision for infection at all time intervals (≤90 days, HR=2.06, 95% confidence interval (CI): 1.75-2.43, P<0.0001; >90 days to 1 year, HR=1.90, 95% CI: 1.58-2.28, P<0.0001; >1 year, HR=1.57, 95% CI: 1.37-1.79, P<0.0001). TKAs performed for osteoarthritis had an increased risk of revision for infection at ≤90 days (HR=2.01, 95% CI: 1.45-2.78, P<0.0001), but not at later times. Mortality was more likely among patients who had a Charlson Comorbidity Index (CCI)≥5 compared to those who had a CCI≤2 (HR=3.21, 95% CI: 1.35-7.63, P=0.008). Mortality was also more likely among older patients (HR=1.61 for each decade, 95% CI: 1.04-2.49, P=0.03).

CONCLUSION

Based on primary TKAs performed in the United States, men were found to have a persistently higher risk of revision for infection, while a diagnosis of osteoarthritis was associated with a significantly higher risk only during the first 90 days after surgery.

What is the Value of a Balanced Total Knee Arthroplasty? Getting it Right the First Time

INTRODUCTION

Instability is a leading cause of early failure following total knee arthroplasty. Enabling technologies can improve accuracy, but their clinical value remains undetermined. The purpose of this study was to determine the value of achieving a balanced knee joint at the time of TKA.

METHODS

A Markov model was developed to determine the value from reduced revisions and improved outcomes associated with TKA joint balance. Patients were modelled for the first 5 years following TKA. The threshold to determine cost-effectiveness was set at an Incremental Cost Effectiveness Ratio (ICER) of $50,000/quality-adjusted life year (QALY). A sensitivity analysis was performed to evaluate the influence of QALY improvement (ΔQALY) and Revision Rate Reduction (ΔRevision) on additional value generated compared to a conventional TKA cohort. The impact of each variable was evaluated by iterating over a range of ΔQALY (0 to 0.046) and ΔRevision (0 to 30%) and calculating the value generated while satisfying the ICER threshold. Finally, the impact of surgeon volume on these outcomes were analyzed.

RESULTS

The total value of a balanced knee for the first 5 years was $8,750, $6,575, and $4,417 per case, for low, medium, and high-volume surgeons, respectively. Change in QALY accounted for greater than 90% of the value gain with a reduction in revisions making up the rest in all scenarios. The economic contribution of revision reduction was relatively constant regardless of surgeon volume ($500/case).

CONCLUSIONS

Achieving a balanced knee had the greatest impact on QALY improvement over early revision rate. These results can help assign value to enabling technologies with joint balancing capabilities.

The Effect of Surgeon and Hospital Volume on Total Hip Arthroplasty Patient-Reported Outcome Measures: An American Joint Replacement Registry Study

BACKGROUND

Some studies have shown lower morbidity and mortality rates with increased surgeon and hospital volumes after total hip arthroplasty (THA). This study sought to determine the relationship between surgeon and hospital volumes and patient-reported outcome measures after THA using American Joint Replacement Registry data.

METHODS

Using American Joint Replacement Registry data from 2012 to 2020, 4,447 primary, elective THAs with both preoperative and 1-year postoperative Hip Dysfunction and Osteoarthritis Outcome Score for Joint Replacement (HOOS-JR) scores were analyzed. This study was powered to detect the minimum clinically important difference (MCID). The main exposure variables were median annual surgeon and hospital volumes. Tertiles were formed based on the median annual number of THAs conducted: low-volume (1 to 42), medium-volume (42 to 96), and high-volume (≥96) surgeons and low-volume (1 to 201), medium-volume (201 to 392), and high-volume (≥392) hospitals. Mean preoperative and 1-year postoperative HOOS-JR scores were compared.

RESULTS

Preoperative HOOS-JR scores were significantly higher at high-volume hospitals than low-volume and medium-volume hospitals (49.66 ± 15.19 vs. 47.68 ± 15.09 and 48.34 ± 15.22, P < 0.001), although these differences were less than the MCID. At the 1-year follow-up, no difference was noted with no resultant MCID. Preoperative and 1-year HOOS-JR scores did not markedly vary with surgeon volume. In multivariate regression, low-volume and medium-volume surgeons and hospitals had similar odds of MCID achievement in HOOS-JR scores compared with high-volume surgeons and hospitals, respectively.

CONCLUSION

Using the HOOS-JR score as a validated patient-reported outcome measure, higher surgeon or hospital THA volume did not correlate with higher postoperative HOOS-JR scores or greater chances of MCID achievement in HOOS-JR scores compared with medium and lower volume surgeons and hospitals.