Projected Prevalence of Obesity in Aseptic Revision Total Hip and Knee Arthroplasty

Background

The purpose of this study was to develop projections of the prevalence of obesity in aseptic revision THA and TKA patients through the year 2029.

Methods

The National Surgical Quality Improvement Project (NSQIP) was queried for years 2011-2019. Current procedural terminology (CPT) codes 27134, 27137, and 27138 were used to identify revision THA and CPT codes 27486 and 27487 were used to identify revision TKA. Revision THA/TKA for infectious, traumatic, or oncologic indications were excluded. Participant data were grouped according to body mass index (BMI) categories: underweight/normal weight, <25 kg/m2; overweight, 25-29.9 kg/m2; class I obesity, 30.034.9 kg/m2; class II obesity, 35.0-39.9 kg/m2; morbid obesity ≥ 40 kg/m2. Prevalence of each BMI category was estimated from year 2020 to year 2029 through multinomial regression analyses.

Results

38,325 cases were included (16,153 revision THA and 22,172 revision TKA). From 2011 to 2029, prevalence of class I obesity (24% to 25%), class II obesity (11% to 15%), and morbid obesity (7% to 9%) increased amongst aseptic revision THA patients. Similarly, prevalence of class I obesity (28% to 30%), class II obesity (17% to 29%), and morbid obesity (16% to 18%) increased in aseptic revision TKA patients.

Conclusion

Prevalence of class II obesity and morbid obesity demonstrated the largest increases in revision TKA and THA patients. By 2029, we estimate that approximately 49% of aseptic revision THA and 77% of aseptic revision TKA will have obesity and/or morbid obesity. Resources aimed at mitigating complications in this patient population are needed. Level of Evidence: III.

Outcomes Vary Significantly Using a Tiered Approach To Define Success After Total Hip Arthroplasty

Background

Clinical outcomes following primary total hip arthroplasty (THA) are commonly assessed through patient-reported outcome measures (PROM). The purpose of this study was to use progressively more stringent definitions of success to evaluate clinical outcomes of primary THA at 1-year postoperatively and to determine if demographic variables were associated with achievement of clinical success.

Methods

The American Joint Replacement Registry (AJRR) was queried from 2012-2020 for primary THA. Patients that completed the following PROMs preoperatively and 1-year postoperatively were included: Western Ontario and McMaster Universities Arthritis Index (WOMAC), Hip Injury and Osteoarthritis Outcome Score (HOOS) and HOOS for Joint Replacement (HOOS, JR). Mean PROM scores were determined for each visit and between-visit changes were evaluated using paired t-tests. Rates of achievement of minimal clinically important difference (MCID) by distribution-based and anchor-based criteria, patient acceptable symptom state (PASS), and substantial clinical benefit (SCB) were calculated. Logistic regression was used to evaluate associations between demographic variables and odds of success.

Results

7,001 THAs were included. Mean improvement in PROM scores were: HOOS, JR, 37; WOMAC-Pain, 39; WOMAC-Function, 41 (p<0.0001 for all). Rates of achievement of each metric were: distribution-based MCID, 88-93%; anchor-based MCID, 68-90%; PASS, 47-84%; SCB, 68-84%. Age and sex were the most influential demographic factors on achievement of clinical success.

Conclusion

There is significant variability in clinical outcomes at 1 year after primary THA when using a tiered approach to define success from the patient's perspective. Tiered approaches to interpretation of PROMs should be considered for future research and clinical assessment. Level of Evidence: III.

The Rise of Medicare Advantage: Effects on Total Joint Arthroplasty Patient Care and Research

BACKGROUND

Medicare Advantage (MA) plans are popular among Medicare-eligible patients, but little is known about MA in lower-extremity total joint arthroplasty (TJA). The purpose of this study was to describe trends in MA utilization and analyze differences in patient characteristics and postoperative outcomes between patients undergoing primary TJA using traditional Medicare (TM) or MA plans.

METHODS

Patients ≥65 years of age who underwent primary total knee or total hip arthroplasty were identified using the Premier Healthcare Database. Patients were categorized into TM and MA cohorts. Data from 2004 to 2020 were used to describe trends in insurance coverage. Data from 2015 to 2020 were used to identify differences in patient characteristics and postoperative complications using ICD-10 codes. Multivariate analyses were performed using 2015 to 2020 data to account for potential confounders.

RESULTS

From 2004 to 2020, the proportion of patients with MA increased from 7.9% to 34.4%, while those with TM decreased from 83.7% to 54.0%. Of the 697,317 patients who underwent primary elective TJA from 2015 to 2020, 471,439 (67.6%) had TM coverage and 225,878 (32.4%) had MA coverage. The cohorts were similar in terms of age and sex. However, a higher proportion of Black patients (8.29% compared with 4.62%; p < 0.001) and a lower proportion of White patients (84.0% compared with 89.2%; p < 0.001) were enrolled in MA compared with TM. After controlling for confounders, patients with MA had higher odds of surgical site infection (adjusted odds ratio [aOR]: 1.15; 95% confidence interval [CI]: 1.04 to 1.47; p = 0.031), periprosthetic joint infection (aOR: 1.10; 95% CI: 1.03 to 1.18; p = 0.006), stroke (aOR: 1.15; 95% CI: 1.02 to 1.31; p = 0.026), and acute kidney injury (aOR: 1.08; 95% CI: 1.04 to 1.11; p < 0.001), but lower odds of urinary tract infection (aOR: 0.94; 95% CI: 0.90 to 0.98; p = 0.003).

CONCLUSIONS

From 2004 to 2020, the number of patients utilizing MA increased markedly such that 1 in 3 were covered by MA in 2020. From 2015 to 2020, patients who were non-White were more likely to have MA than TM, and the MA group had a higher rate of several postoperative complications compared with the TM group. As TM claims data inform health-care policy and clinical decisions, this change portends future challenges, including limitations in arthroplasty registry research, an increase in the administrative burden of surgeons, and a potential worsening of social disparities in health care.

Rates of Antimicrobial Resistance With Extended Oral Antibiotic Prophylaxis After Total Joint Arthroplasty

Background

There is increased interest and utilization of extended oral antibiotic prophylaxis (EOAP) following primary and revision total hip arthroplasties (THAs) and total knee arthroplasties (TKAs). The purpose of this study was to look for potential associations between EOAP and differential rates of antimicrobial resistance or epidemiology of organisms causing periprosthetic joint infection (PJI) following primary and aseptic revision THAs/TKAs.

Methods

Patients who developed PJI following a primary or aseptic revision TKA/THA at a single institution from 2009 to 2020 were retrospectively identified. Patients who received at least 7 days of EOAP following the surgery were noted. Rates of antimicrobial resistance were compared between standard antibiotic prophylaxis and EOAP cohorts using the Fisher's exact test.

Results

One hundred twenty-eight cultures were obtained from 119 patients with PJI. Fourty-four cases (37%) developed PJI after EOAP. Staphylococcus aureus was the most frequently isolated organism (30% of all cultures; 78% were methicillin-sensitive). Rates of antimicrobial resistance were similar between standard antibiotic prophylaxis and EOAP cohorts in all but 2 instances: Increased resistance to erythromycin and trimethoprim-sulfamethoxazole was observed in coagulase-negative Staphylococci isolates in the EOAP cohort (89% vs 21%, P < .01; 44% vs 0%, P = .02). An increased frequency of gram-negative organisms was observed in the EOAP group (22% vs 8%, P = .03).

Conclusions

Rates of antimicrobial resistance were not significantly different between EOAP and standard antibiotic prophylaxis cohorts except in coagulase-negative Staphylococci. The increased frequency of gram-negative infections was present in the EOAP cohort. Larger, multicenter studies are needed to better understand the impact of EOAP on antimicrobial resistance and PJI epidemiology.

Level of Evidence

Level III; retrospective cohort study.

Administrative Data Use in National Registry Efforts: Blessing or Curse?

"Big data" refers to a growing field of large database research. Administrative data, a subset of big data, includes information from insurance claims, electronic medical records, and registries that can be useful for investigating novel research questions. While its use provides salient advantages, potential researchers relying on big data would benefit from knowing about how these databases are coded, common errors they may encounter, and how to best use large data to address various research questions. In the first section of this paper, Dr. Nicholas A. Bedard addresses the four major pitfalls to avoid with diagnosis and procedure codes in administrative data. In the next section, Dr. Jeffrey N. Katz et al. focus on the strengths and limitations of administrative data, suggesting methods to mitigate these limitations. Lastly, Dr. Elena Losina et al. review the uses and misuses of large databases for cost-effectiveness research, detailing methods for careful economic evaluations.

Analysis of New Orthopaedic Technologies in Large Database Research

Improvements in orthopaedic surgery go hand in hand with technological advances. The present article outlines the historical and current uses of large databases and registries for the evaluation of new orthopaedic technologies, providing insights for future utilization, with robotic-assisted surgery as the example technology.

Making a Joint Decision Regarding the Timing of Surgery for Elective Arthroplasty Surgery After Being Infected With COVID-19: A Systematic Review

BACKGROUND

The Coronavirus Disease 2019 (COVID-19) pandemic has caused a substantial number of patients to have their elective arthroplasty surgeries rescheduled. While it is established that patients with COVID-19 who are undergoing surgery have a significantly higher risk of experiencing postoperative complications and mortality, it is not well-known at what time after testing positive the risk of postoperative complications or mortality returns to normal.

METHODS

PubMed (MEDLINE), Excerpta Medica dataBASE, and professional society websites were systematically reviewed on March 7, 2022 to identify studies and guidelines on the optimal timeframe to reschedule patients for elective surgery after preoperatively testing positive for COVID-19. Outcomes included postoperative complications such as mortality, pneumonia, acute respiratory distress syndrome, septic shock, and pulmonary embolism.

RESULTS

A total of 14 studies and professional society guidelines met the inclusion criteria for this systematic review. Patients with asymptomatic COVID-19 should be rescheduled 4-8 weeks after testing positive (as long as they do not develop symptoms in the interim), patients with mild/moderate COVID-19 should be rescheduled 6-8 weeks after testing positive (with complete resolution of symptoms), and patients with severe/critical COVID-19 should be rescheduled at a minimum of 12 weeks after hospital discharge (with complete resolution of symptoms).

CONCLUSIONS

Given the negative association between preoperative COVID-19 and postoperative complications, patients should have elective arthroplasty surgery rescheduled at differing timeframes based on their symptoms. In addition, a multidisciplinary and patient-centered approach to rescheduling patients is recommended. Further study is needed to examine the impact of novel COVID-19 variants and vaccination on timeframes for rescheduling surgery.

Not all Total Hip and Knee Arthroplasties Are the Same: What Are the Implications in Large Database Studies?

BACKGROUND

The use of claims databases for research after total hip and knee arthroplasty (THA, TKA) has increased exponentially. These studies rely on accurate coding, and inadvertent inclusion of patients with nonroutine indications may influence results. The purpose of this study was to evaluate the complexity of THA and TKA captured by CPT code and determine if complication rates vary based on the indication.

METHODS

The NSQIP database was queried using CPT codes 21730 and 27447 to identify patients undergoing THA and TKA from 2018 to 2019. The surgical indication was classified based on the ICD-10 diagnosis code as routine primary, complex primary, inflammatory, fracture, oncologic, revision, infection, or indeterminant. Patient factors and 30-day complications, readmission, reoperation, and wound complications were compared.

RESULTS

A total of 86,009 THA patients had 703 ICD-10 diagnosis codes and 91.4% were routine primary indications. Complication rates were: routine primary 7.4%, complex primary 11.3%, inflammatory 12.5%, fracture 23.9%, oncologic 32.4%, revision 26.9%, infection 38.7%, and indeterminant 10.3% (P < .0001). 137,500 TKA patients had 552 ICD-10 diagnosis codes and 96.1% were routine primary cases. Complication rates were: routine primary 5.9%, complex primary 8.0%, inflammatory 7.2%, fracture 38.9%, oncologic 32.7%, revision 13.3%, infection 37.7%, and indeterminant 9.6% (P < .0001). Routine primary arthroplasty had significantly lower rates of reoperation, readmission, and wound complications.

CONCLUSION

Using CPT code alone captures 10% of THA and 4% of TKA patients with procedures for nonroutine primary indications. It is essential to recognize identification of patients simply by CPT code has the potential to inadvertently introduce bias, and surgeons should critically assess methods used to define the study populations.

Perioperative Opioid Counseling Reduces Opioid Use Following Primary Total Joint Arthroplasty

BACKGROUND

Preoperative counseling may reduce postoperative opioid requirements; however, there is a paucity of randomized controlled trials (RCTs) demonstrating efficacy. The purpose of this study was to perform an interventional, telehealth-based RCT evaluating the effect of peri-operative counseling on quantity and duration of opioid consumption following primary total joint arthroplasty (TJA).

METHODS

Participants were randomized into three groups: 1. Control group, no perioperative counseling; 2. Intervention group, preoperative educational video; 3. Intervention group, preoperative educational video and postoperative acceptance and commitment therapy (ACT). Opioid consumption was evaluated daily for 14 days and at 6 weeks postoperatively. Best-case and worse-case intention to treat analyses were performed to account for non-responses. Bonferroni corrections were applied.

RESULTS

183 participants were analyzed (63 in Group 1, 55 in Group 2, and 65 in Group 3). At 2 weeks postoperatively, there was no difference in opioid consumption between Groups 1, 2, and 3 (p>0.05 for all). At 6 weeks postoperatively, Groups 2 and 3 had consumed significantly less opioids than Group 1 (p=0.04, p<0.001) (Table 1). Group 3 participants were less likely to obtain an opioid refill relative to Group 1 participants (p=0.04). Participants in groups 2 and 3 ceased opioid consumption a median of 6 days and 2 days sooner than Group 1, respectively (p<0.001, p=0.03) (Table 2).

CONCLUSION

Perioperative opioid counseling significantly decreases the quantity and duration of opioid consumption at 6 weeks following primary TJA. Level of Evidence: I.

Operative Time and Risk of Surgical Site Infection and Periprosthetic Joint Infection: A Systematic Review and Meta-Analysis

BACKGROUND

The purpose of this study was to perform a systematic review and meta-analysis on the association between operative time and peri-prosthetic joint infection (PJI) after primary total hip arthroplasty (THA) and total knee arthroplasty (TKA).

METHODS

PubMed, Embase, and Cochrane CENTRAL databases were searched for relevant articles dating 2000-2020. Relationship of operative time and PJI rate in primary total joint arthroplasty (TJA) was evaluated by pooled odds ratios (OR) and 95% confidence intervals.

RESULTS

Six studies were identified for meta-analysis. TJA lasting greater than 120 minutes had greater odds of PJI (OR, 1.63 [1.00-2.66], p=0.048). Similarly, there were greater odds of PJI for TJA procedures lasting greater than 90 minutes (OR, 1.65 [1.27-2.14]; p<0.001). Separate analyses of TKA (OR, 2.01 [0.76-5.30]) and THA (OR, 1.06 [0.80-1.39]) demonstrated no difference in rates of PJI in cases of operative time ≥ 120 minutes versus cases < 120 minutes (p>0.05 for all). Using any surgical site infection (SSI) as an endpoint, both TJA (OR, 1.47 [1.181.83], p<0.001) and TKA (OR, 1.50 [1.08-2.08]; p=0.016) procedures lasting more versus less than 120 minutes demonstrated significantly higher odds of SSI.

CONCLUSION

Following TJA, rates of SSI and PJI are significantly greater in procedures ≥120 minutes in duration relative to those < 120 minutes. When analyzing TKA separately, higher rates of SSI were observed in procedures ≥ 120 minutes in duration relative to those <120 minutes. Rates of PJI in TKA or THA procedures alone were not significantly impacted by operative time. Level of Evidence: V.

Who Is Still Receiving Blood Transfusions After Primary and Revision Total Joint Arthroplasty?

BACKGROUND

Incidence of blood transfusions after primary and revision total hip and knee arthroplasty (primary total hip arthroplasty [pTHA], revision THA [rTHA], primary total knee arthroplasty [pTKA], and revision TKA [rTKA]) has been decreasing for a multitude of reasons. The purpose of this study was to assess whether transfusion rates have continued to decline and evaluate patient factors associated with transfusions.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program was queried to identify patients undergoing pTHA, pTKA, rTHA, and rTKA between 2011 and 2019. Patients undergoing bilateral procedures and arthroplasty for fracture, infection, or tumor were excluded. Trends in blood transfusions were assessed. Patient factor association with blood transfusions was evaluated using 2018 and 2019 data.

RESULTS

Transfusion rates decreased from 21.4% in 2011 to 2.5% in 2019 for pTHA (P < .0001). For pTKA, transfusion rates declined from 17.6% to 0.7% (P < .0001). In rTHA, the transfusion rate decreased from 33.5% to 12.0% from 2011 to 2019 (P < .0001). Transfusion rates declined from 19.4% to 2.6% for rTKA during the study period (P < .0001). Transfusions were more frequent in patients who were older, female, with more comorbidities, with lower hematocrit, receiving nonspinal anesthesia, and with longer operative time. Lower preoperative hematocrit, history of bleeding disorders, and preoperative transfusion were associated with greater odds for postoperative transfusion after multivariate analysis.

CONCLUSION

Transfusions after both primary and revision total joint arthroplasty have continued to decrease. Studies of arthroplasty complications should account for decreasing transfusions when assessing overall complication rates. Future studies should consider interventions to further reduce transfusions in revision arthroplasty.

Are Body Mass Index Cutoffs Creating Racial, Ethnic, and Gender Disparities in Eligibility for Primary Total Hip and Knee Arthroplasty?

BACKGROUND

Unabated increases in the prevalence of obesity among American adults have disproportionately affected women, Black persons, and Hispanic persons. The purpose of this study was to evaluate for disparity in rates of patient eligibility for primary total hip arthroplasty (THA) and total knee arthroplasty (TKA) based on race and ethnicity and gender by applying commonly used body mass index (BMI) eligibility criteria to two large national databases.

METHODS

We retrospectively reviewed data from the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database for the years 2015-2019 for primary THA and TKA and the National Health and Nutrition Examination Survey (NHANES) from 2011-2018. Designations of race and ethnicity were standardized between cohorts. BMI cutoffs of <50 kg/m², <45 kg/m², <40 kg/m², and <35 kg/m² were then applied. Rates of eligibility for surgery were examined for each respective BMI cutoff and stratified by age, race and ethnicity, and gender.

RESULTS

143,973 NSQIP THA patients, 242,518 NSQIP TKA patients, and 13,255 NHANES participants were analyzed. Female patients were more likely to be ineligible for surgery across all cohorts for all modeled BMI cutoffs (P < .001 for all). Black patients had relatively lower rates of eligibility across all cohorts for all modeled BMI cutoffs (P < .0001 for all). Hispanic patients had disproportionately lower rates of eligibility only at a BMI cutoff of <35 kg/m².

CONCLUSION

Using BMI cutoffs alone to determine the eligibility for primary THA and TKA may disproportionally exclude women, Black persons, and Hispanic persons. These data raise concerns regarding further disparity and restriction of arthroplasty care to vulnerable populations that are already marginalized.

LEVEL OF EVIDENCE

Retrospective Cohort Study, Level III.

Projected Prevalence of Obesity in Primary Total Hip Arthroplasty: How Big Will the Problem Get?

BACKGROUND

Obesity is associated with higher rates of adverse outcomes following primary total hip arthroplasty (THA). The purpose of this study is to utilize 3 national databases to develop projections of obesity within the general population and primary THA patients in the United States through 2029.

METHODS

Data from the National Surgical Quality Improvement Program (NSQIP), the Behavior Risk Factor Surveillance System (BRFSS), and the National Health and Nutrition Examination Survey were queried for years 1999-2019. Current Procedural Terminology code 27130 was used to identify primary THA patients in NSQIP. Individuals were categorized according to body mass index (kg/m²) by year: normal weight (≤24.9); overweight (25.0-29.9); obese (30.0-39.9); and morbidly obese (≥40). Multinomial logistic regression was used to project categorical body mass index data for years 2020-2029.

RESULTS

A total of 8,222,013 individuals were included (7,986,414 BRFSS, 235,599 NSQIP THA). From 2011 to 2019, the prevalence of normal weight and overweight individuals declined in the general population (BRFSS) and in primary THA. Prevalence of obese/morbidly obese individuals increased in the general population from 31% to 36% and in primary THA from 42% to 49%. Projection models estimate that by 2029, 46% of the general population will be obese/morbidly obese and 55% of primary THA will be obese/morbidly obese.

CONCLUSION

By 2029, we estimate ≥55% of primary THA to be obese/morbidly obese. Increased resources dedicated to care pathways and research focused on improving outcomes in obese arthroplasty patients will be necessary as this population continues to grow.

LEVEL OF EVIDENCE

Level III, Retrospective Cohort Study.

Increased Risk of Short-Term Complications in Smokers Undergoing Primary Unicompartmental Knee Arthroplasty

The effects of smoking on unicompartmental knee arthroplasty (UKA) are unknown. The purpose of this study was to evaluate the effects of smoking on short-term outcomes following primary UKA. A query of the National Surgical Quality Improvement Project (NSQIP) database was used to identify cases of primary UKA performed during years 2006 to 2017. Patient demographics, operative times, and postoperative complications were compared between smoking and nonsmoking cohorts. Descriptive statistics, univariate analyses, and multivariate analyses were conducted to evaluate the effects of smoking on primary UKA. A total of 10,593 cases of UKA were identified; 1,046 of these patients were smokers. Univariate analysis demonstrated smokers to have higher rates of any complication (4.6 vs. 3.3%, p = 0.031), any wound complication (1.82 vs. 0.94%, p = 0.008), deep wound infection (0.57 vs. 0.13%, p = 0.006), and reoperation (1.34 vs. 0.68%, p = 0.018) relative to nonsmokers. Multivariate analysis demonstrated smokers to have higher rates of any wound complication (odds ratio [OR] = 1.79; 95% confidence interval [CI]: 1.06-2.95) and reoperation (OR = 2.11; 95% CI: 1.12-3.97). Smokers undergoing primary UKA are at higher risk for any wound complication and reoperation relative to nonsmokers in the first 30 days postoperatively. Further studies evaluating the long-term effects of smoking on outcome following UKA, as well as the impact of smoking cessation on outcomes following UKA, are needed.

What is the Impact of Body Mass Index Cutoffs on Total Knee Arthroplasty Complications?

BACKGROUND

Body mass index (BMI) cutoffs are commonly used to decide whether to offer obese patients elective total knee arthroplasty (TKA). However, weight loss goals may be unachievable for many patients who are consequentially denied complication-free surgery. The purpose of this study was to assess the impact of different BMI cutoffs on the rates of complication-free surgery after TKA.

METHODS

Patients undergoing elective, primary TKA from 2015 to 2018 were identified in the American College of Surgeons National Surgical Quality Improvement Program database using Common Procedural Terminology code 27447. The BMI and rates of any thirty-day complication were collected. BMI cutoffs of 30, 35, 40, 45, and 50 kg/m² were applied to model the incidence of complications if TKA would have been allowed or denied based on the BMI.

RESULTS

A total of 314,719 patients underwent TKA, and 46,386 (14.7%) had a BMI ≥40 kg/m². With a BMI cutoff of 40 kg/m², 268,333 (85.3%) patients would have undergone TKA. A total of 282,552 (94.8%) would experience complication-free surgery, and 17.3% of all complications would be prevented. TKA would proceed for 309,479 (98.3%) patients at a BMI cutoff of 50 kg/m². A total of 293,108 (94.7%) would not experience a complication, and 2.8% of complications would be prevented. A BMI cutoff of 35 kg/m² would prevent 36.6% of all complications while allowing 94.8% of complication-free surgeries to proceed.

CONCLUSION

Lower BMI cutoffs can reduce complications, but will limit access to complication-free TKA for many patients. These data do not indicate TKA should be performed without consideration of risks from obesity; however, a holistic assessment and shared decision-making may be more valuable when deciding on appropriate goal weight reduction.

Can Abnormal Spinopelvic Relationships be Identified by Anteroposterior Pelvic Radiographs?

BACKGROUND

Abnormal spinopelvic relationships may place patients at an increased risk for instability after primary total hip arthroplasty. The purpose of this study was to determine if radiographic markers on a standing anteroposterior (AP) pelvis radiograph could identify patients with sagittal spinopelvic imbalance or spinal stiffness.

METHODS

Patients undergoing primary total hip arthroplasty at a single institution from 2017 to 2020 with standing AP pelvis radiographs and sitting/standing lateral radiographs were identified. AP pelvis radiographs were assessed for the following: lumbosacral hardware, spine osteophytes, disc space narrowing, scoliosis>5°, pelvic obliquity>5°, and overlap of the sacrococcygeal junction/pubic symphysis. Patients with spinopelvic imbalance and/or spinopelvic stiffness were identified. Univariate and multivariate analyses were performed. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated.

RESULTS

Four hundred eighty-six patients were included. Prevalence of isolated sagittal spinopelvic imbalance and isolated spinopelvic stiffness was 12% and 21%, respectively; 11% of patients had sagittal imbalance and stiffness. Overlap of the sacrococcygeal junction/pubic symphysis (OR = 10.2, 95% CI = 5.3-19.8) and presence of lumbosacral hardware (OR = 4.4, 95% CI = 2.0-9.4) were markers of an increased risk of combined sagittal imbalance and stiffness. Seventy-nine percent of patients with overlap of the sacrococcygeal junction and pubic symphysis and 82% of patients with lumbosacral hardware had an abnormal spinopelvic relationship.

CONCLUSION

Isolated sagittal imbalance and stiffness were difficult to predict on standing AP pelvis radiographs. Overlap of the sacrococcygeal junction/pubic symphysis and presence of lumbosacral hardware associated with a higher risk of combined sagittal imbalance/stiffness and were present in ≥79% of patients with an abnormal spinopelvic relationship.

LEVEL OF EVIDENCE

IV; retrospective cohort study.

Are Morbidly Obese Patients Equally Benefitting From Care Improvements in Total Hip Arthroplasty?

BACKGROUND

Morbidly obese patients have increased rates of complications following primary total hip arthroplasty (THA) and it is not clear whether improvements in THA care pathways are equally benefitting these patients. The purpose of this study is to assess if reductions in complications have similarly improved for both morbidly obese and non-morbidly obese patients after THA.

METHODS

Patients undergoing primary THA between 2011 and 2019 were identified in the American College of Surgeons National Surgical Quality Improvement Program database. Patients were stratified by body mass index (BMI) <40 and ≥40 kg/m². Thirty-day rates of infectious complications, readmissions, reoperation, and any complication were assessed. Trends in complications were compared utilizing odds ratios and multivariate analyses.

RESULTS

In total, 234,334 patients underwent THA and 16,979 (7.8%) had BMI ≥40 kg/m². Patients with BMI ≥40 kg/m² were at significantly higher odds for readmission, reoperation, and infectious complications. Odds for any complication were lower for morbidly obese patients in 2011, not different from 2012 to 2014, and higher from 2015 to 2019 compared to lower BMI patients. Odds for any non-transfusion complication were higher for morbidly obese patients and there was no improvement for either group over the study period. There were improvements in rates of readmission and reoperation for patients with BMI <40 kg/m² and readmission for BMI >40 kg/m².

CONCLUSION

Odds for readmission and reoperation for non-morbidly obese patients and readmission for morbidly obese patients improved from 2011 to 2019. Reductions in transfusions are largely responsible for improvements in overall complication rates. Although morbidly obese patients remain at higher risk for complications, there does not appear to be a growing disparity in outcomes between morbidly obese and non-morbidly obese patients.

Use of Cementless Metaphyseal Fixation in Revision Total Knee Arthroplasty in the United States

BACKGROUND

Fixation options for revision total knee arthroplasty (rTKA) have expanded and now include cementless metaphyseal fixation. The utilization rates of these implants in the United States are not well known. The purpose of this study was to analyze trends in cementless metaphyseal fixation for rTKA within the American Joint Replacement Registry (AJRR).

METHODS

The AJRR was queried for the years 2015-2019 to identify all rTKA with implant data. Trends in the use of cementless sleeves, metaphyseal cones, and any cementless metaphyseal fixation (sleeves + cones) were examined over the study period using logistic regression analysis.

RESULTS

Twenty thousand two hundred and eighty rTKA were analyzed. Cementless metaphyseal fixation was used in 16% of rTKA and significantly increased over the study period (14% to 19%, P < .0001). Cementless metaphyseal fixation was more frequently utilized during revision for aseptic loosening than other diagnoses (OR 1.014, 95% CI 1.001-1.027). Cementless sleeve utilization decreased over time (11% to 9%, P = .004), driven by decreased use on the femur (4% to 2%, P < .0001). The use of cones increased significantly over time (3% to 9%, P < .0001), driven by increased use on the tibia (2% to 9%, P < .0001). Cones were 22 times more likely to be utilized on the tibia relative to the femur (P < .0001) and were more likely to be used in revisions for infection (OR 1.103, 95% CI 1.089-1.117) and aseptic loosening (OR 1.764, 95% CI 1.728-1.800).

CONCLUSION

Cementless metaphyseal fixation has grown in popularity yet, still comprised only 16% of rTKA over a 5-year period. Most of the increase was due to the utilization of tibial metaphyseal cones.

A Psycholgical Intervention Delivered by Automated Mobile Phone Messaging Stabilized Hip and Knee Function During the COVID-19 Pandemic: A Randomized Controlled Trial

BACKGROUND

We conducted a randomized controlled trial to evaluate the effectiveness of acceptance and commitment therapy (ACT) delivered via a mobile phone messaging robot to patients who had their total hip arthroplasty or total knee arthroplasty procedures postponed due to the COVID-19 pandemic.

METHODS

Ninety patients scheduled for total hip arthroplasty or total knee arthroplasty who experienced surgical delay due to the COVID-19 pandemic were randomized to the ACT group, receiving 14 days of twice daily automated mobile phone messages, or the control group, who received no messages. Minimal clinically important differences (MCIDs) in preintervention and postintervention patient-reported outcome measures were utilized to evaluate the intervention.

RESULTS

Thirty-eight percent of ACT group participants improved and achieved MCID on the Patient-Reported Outcome Measure Information System Physical Health compared to 17.5% in the control group (P = .038; number needed to treat [NNT] 5). For the joint-specific Hip Disability and Osteoarthritis Outcome Score Joint Replacement and Knee Disability and Osteoarthritis Outcome Score Joint Replacement (KOOS JR), 24% of the ACT group achieved MCID compared to 2.5% in the control group (P = .004; NNT 5). An improvement in the KOOS JR was found in 29% of the ACT group compared to 4.2% in the control group (P = .028; NNT 5). Fourteen percent of the ACT group participants experienced a clinical important decline in the KOOS JR compared to 41.7% in the control group (P = .027; NNT 4).

CONCLUSION

A psychological intervention delivered via a text messaging robot improved physical function and prevented decline in patient-reported outcome measures in patients who experienced an unexpected surgical delay during the COVID-19 pandemic.

LEVEL OF EVIDENCE

1.

Is There a Time-Dependent Contamination Risk to Open Surgical Trays During Total Hip and Knee Arthroplasty?

Background

Periprosthetic joint infection (PJI) after total hip and knee arthroplasty (TJA) is a devastating complication and intraoperative contamination can be a source for PJI. Currently, many measures are performed intraoperatively to reduce the risk of contamination. The primary purpose of this study was to determine if there is a time-dependent risk of contamination to open sterile surgical trays during TJA cases.

Methods

A prospective intraoperative culture swab study was performed. Standard sterile operating room trays without instruments were utilized as the experimental trays. These were opened simultaneously with all other surgical instrumentation needed for the procedure. These trays were left on an isolated Mayo stand next to the scrub tech's table and swabbed at 30-minute intervals. The first swab was performed immediately after opening all sets and the last swab performed on closure of the incision. A new section of the grid-lined tray was swabbed for each data point and the culture analysis was conducted by our institutions' microbiology lab for both quantitative and qualitative analysis. Operating suite room temperature and humidity data was also gathered.

Results

Twenty-three consecutive primary TJA cases in high air turnover rooms were included. 13 of the 23 (57%) cases demonstrated culture positive bacterial growth on at least one time point. Of the 109 independent swabs collected, 19 (17%) had bacterial growth. The most common bacterial species isolated was Staphylococcus epidermidis. There were no statistically significant associations between time (p= 0.35), operating room (OR) temperature (p = 0.99), and OR humidity (p = 0.07) and with bacterial growth.

Conclusion

In spite of isolating an organism in 57% of cases, we could not identify a time-dependent increase in bacterial contamination throughout our operative cases. We were unable to associate OR environmental temperature and humidity to bacterial growth. Level of Evidence: II.

Longer Length of Stay Is Associated With More Early Complications After Total Knee Arthroplasty

Background

Length of stay (LOS) following total knee arthroplasty (TKA) has decreased over recently years. In 2018, the Centers for Medicare and Medicaid Services removed TKA from Inpatient-Only List (IPO), incentivizing further expansion of outpatient TKA. However, many patients may still require postsurgical hospitalization. The purpose of this study was to assess early outcomes for TKA based on length of stay (LOS).

Methods

We identified patients undergoing elective, primary TKA in the National Surgical Quality Improvement Program database using CPT code 27447 between 2015 and 2018. Patients were stratified by length of stay (LOS) 0 days, 1-2 days, and ≥3 days. Thirty-day rates of any complication, wound complications, readmission, and reoperation were assessed. Multivariate analysis was performed to adjust for confounding variables.

Results

5,655 (3%) patients underwent outpatient TKA, 130,543 (59%) had LOS 1-2 days, and 84,986 (38%) had LOS ≥3 days. Any complication was experienced in 4.1% of those with LOS 0 days, 4.3% for those with LOS of 1-2 days, and 10.5% for patients with LOS ≥3 days (p<0.0001). Readmission occurred in 2.2%, 2.6%, and 4.0% for the 3 groups, respectively (p<0.0001). After multivariate analysis, there was no significant difference in any outcome measure between patients with LOS 0 and 1-2 days, however those with LOS ≥3 days had higher odds of complications, reoperation, and readmission.

Conclusion

A significant number of patients had LOS ≥3 days following TKA and had more comorbidities and complications. Outpatient TKA was not associated with increased early complication compared to those with LOS of 1-2 days. Despite expansion of outpatient surgery, postsurgical hospitalization remains an integral part of care following TKA. Level of Evidence: III.

What is the Level of Evidence Substantiating Commercial Payers' Coverage Policies for Total Joint Arthroplasty?

BACKGROUND

The prevalence of total joint arthroplasty (TJA) in the United States has drawn the attention of health care stakeholders. The payers have also used a variety of strategies to regulate the medical necessity of these procedures. The purpose of this study was to examine the level of evidence of the coverage policies being used by commercial payers in the United States.

METHODS

The references of the coverage policies of four commercial insurance companies were reviewed for type of document, level of evidence, applicability to a TJA population, and success of nonoperative treatment in patients with severe degenerative joint disease.

RESULTS

282 documents were reviewed. 45.8% were primary journal articles, 14.2% were level I or II, 41.2% were applicable to patients who were candidates for TJA, and 9.9% discussed the success of nonoperative treatment in patients who would be candidates for TJA.

CONCLUSION

Most of the references cited by commercial payers are of a lower level of scientific evidence and not applicable to patients considered to be candidates for TJA. This is relatively uniform across the reviewed payers. The dearth of high-quality literature cited by commercial payers reflects the lack of evidence and difficulty in conducting high level studies on the outcomes of nonoperative versus operative treatment for patients with severe, symptomatic osteoarthritis. Patients, surgeons, and payers would all benefit from such studies and we encourage professional societies to strive toward that end through multicenter collaboration.

Do Extended Oral Postoperative Antibiotics Prevent Early Periprosthetic Joint Infection in Morbidly Obese Patients Undergoing Primary Total Joint Arthroplasty?

BACKGROUND

Extended oral antibiotic prophylaxis after primary total knee arthroplasty (TKA) and total hip arthroplasty (THA) in patients with body mass index (BMI) ≥40 kg/m² may reduce the rate of early periprosthetic joint infection (PJI); however, existing data are limited. The purpose of this study was to examine rates of wound complications and PJI in patients with BMI ≥40 kg/m² treated with and without extended oral antibiotic prophylaxis after surgery.

METHODS

We retrospectively identified all primary THA and TKA performed since 2015 in patients with a BMI ≥40 kg/m² at a single institution. Extended oral antibiotic prophylaxis for 7-14 days after surgery was prescribed at the discretion of each surgeon. Wound complications and PJI were examined at 90 days postoperatively.

RESULTS

In total, 650 cases (205 THA and 445 TKA) were analyzed. Mean age was 58 years and 62% were women. Mean BMI was 44 kg/m². Extended oral antibiotic prophylaxis was prescribed in 177 cases (27%). At 90 days, there was no difference between prophylaxis and nonprophylaxis groups in rate of wound complications (11% vs 8%; P = .41) or PJI (1.7% vs 0.6%; P = .35). The univariate analysis demonstrated increased operative time (odds ratio (OR) 1.01; 95% confidence interval (95% CI) 1.01-1.02) and diabetes mellitus (OR 1.88; 95% CI 1.03-3.46) to be associated with increased risk of 90-day wound complications. No patient factors were associated with increased risk of PJI at 90 days postoperatively.

CONCLUSION

Extended oral antibiotic prophylaxis after primary THA and TKA did not reduce rates of wound complications or early PJI in a morbidly obese patient population.

Has Removal From the Inpatient-Only List Increased Complications After Outpatient Total Knee Arthroplasty?

BACKGROUND

On 1/1/2018, the Centers for Medicare and Medicaid Services removed total knee arthroplasty (TKA) from the Inpatient-Only (IPO) list. This change allowed expansion of outpatient TKA, potentially to include older, more frail patients at greater risk for perioperative complications. The purpose of this study was to evaluate the impact of removing TKA from the IPO list on early complications.

METHODS

Patients undergoing TKA in the National Surgical Quality Improvement Program database were identified using CPT code 27447. Only cases with length of stay of zero days were included. Rates of 30-day complications, readmissions, and reoperation were compared before and after TKA was removed from the IPO list (2015-2017 vs 2018). The analysis was performed both with and without propensity score matching.

RESULTS

212,313 patients underwent TKA during the study period. 2466 (1.5%) were outpatient TKA in 2015-2017 and 3189 (5.6%) in 2018. After propensity matching, there were 2458 patients in each cohort. Rates of total 30-day complications were significantly lower in 2018 (3.7%) than the years TKA remained on the IPO (4.5%, P = .04). Similarly, rates of any reoperation decreased from 1.2% during 2015-2017 to 0.6% in 2018 (P = .03). There were no significant changes in rates of readmission (2.5% vs 2.2%, P = .5) or wound complications (0.8% vs 0.8%, P = 1.0).

CONCLUSION

Removal of TKA from the IPO list did not result in an increase in complications or readmissions. These data suggest, despite the regulatory change, surgeons have continued to exercise sound judgment as to what patients can safely undergo outpatient TKA.