Interim Spacer Exchange for Treatment of Periprosthetic Joint Infection: Almost Half the Patients Subsequently Fail.

BACKGROUND: Interim spacer exchange may be performed in patients undergoing 2-stage exchange for periprosthetic joint infection. Several studies have demonstrated that interim spacer exchange is associated with poor outcomes. This study investigated the survivorship and risk factors for failure in patients with an interim spacer exchange. METHODS: Two institutional databases identified 182 patients who underwent spacer exchange from 2000 to 2017. Primary outcomes included progression to reimplantation, treatment success, and mortality. Bivariate analysis was performed to evaluate risk factors associated with failure. Kaplan-Meier curves using host and local grades were generated to evaluate for primary outcomes and differences in survivorship. RESULTS: The overall failure rate was 49% in patients with a spacer exchange. Most patients (60%) failed before 2 years. Higher comorbidity scores, elevated erythrocyte sedimentation rate, and non-White race were more prevalent in patients who failed. Negative cultures at the time of exchange were more prevalent in patients who did not fail. Failure rate was higher in immunocompromised conditions, and those who had revision prior to exchange. After considering clinically relevant variables, advanced host grade C was the single factor associated with treatment failure. Although survivorship curves were not significantly different between extremity local grades, higher host grades were associated with treatment failure. CONCLUSION: Almost 1 out of 2 patients with spacer exchange were found to fail the intended 2-stage revision arthroplasty. Benefits of delivering additional antibiotic load with a new spacer should be balanced against poor outcomes in patients with the aforementioned risk factors.

Psoriasis and Post-Surgical Infections in Primary Total Knee Arthroplasty: An Analysis of 10,727 Patients.

BACKGROUND: Psoriasis is a dermatologic condition characterized by erythematous plaques that may increase wound complications and deep infections following total knee arthroplasty (TKA). There is a paucity of evidence concerning the association of this disease and complications after TKA. This study aimed to determine if patients who have psoriasis vs non-psoriatic patients have differences in demographics and various comorbidities as well as post-operative infections, specifically the following: (1) wound complications; (2) cellulitic episodes; and (3) deep surgical site infections (SSIs). METHODS: We identified 10,727 patients undergoing primary TKA utilizing an institutional database between January 1, 2017 and April 1, 2019. A total of 133 patients who had psoriasis (1.2%) were identified using International Classification of Diseases, Tenth Revision codes and compared to non-psoriatic patients. The rate of wound complications, cellulitic episodes, and deep SSIs were determined. After controlling for age and various comorbidities, multivariate analyses were performed to identify the associated risks for post-operative infections. RESULTS: Psoriasis patients showed an increased associated risk of deep SSIs (3.8%) compared to non-psoriasis patients (1.2%, P = .023). Multivariate analyses demonstrated a significant associated risk of deep SSIs (odds ratio 7.04, 95% confidence interval 2.38-20.9, P < .001) and wound complications (odds ratio 4.44, 95% confidence interval 1.02-19.2, P = .047). CONCLUSION: Psoriasis is an inflammatory dermatologic condition that warrants increased pre-operative counseling, shared decision-making, and infectious precautions in the TKA population given the increased risk of wound complications and deep SSIs. Increased vigilance is required given the coexistence of certain comorbidities with this population, including depression, substance use disorder, smoking history, gastroesophageal reflux disease, and inflammatory bowel disease.

The Potential Effects of Imposing a Body Mass Index Threshold on Patient-Reported Outcomes After Total Knee Arthroplasty.

BACKGROUND: Operative eligibility thresholds based on body mass index (BMI) alone may risk restricting access to improved pain control, function, and quality of life. This study evaluated the use of BMI-cutoffs to offering TKA in avoiding: 1) 90-day readmission, 2) one-year mortality, and 3) failure to achieve clinically important one-year PROMS improvement (MCID). METHODS: A total of 4126 primary elective unilateral TKA patients from 2015 to 2018 were prospectively collected. For specific BMI(kg/m2) cutoffs: 30, 35, 40, 45, and 50, the positive predictive value (PPV) for 90-day readmission, one-year mortality, and failure to achieve one-year MCID were calculated. The number of patients denied complication-free postoperative courses per averted adverse outcome/failed improvement was estimated. RESULTS: Rates of 90-day readmission and one-year mortality were similar across BMI categories (P > .05, each). PPVs for preventing 90-day readmission and one-year mortality were low across all models of BMI cutoffs. The highest PPV for 90-day readmission and one-year mortality was detected at cutoffs of 45 (6.4%) and 40 (0.87%), respectively. BMI cutoff of 40 would deny 18 patients 90-day readmission-free, and 194 patients one-year mortality-free postoperative courses for each averted 90-day readmission/one-year mortality. Such cutoff would also deny 11 patients an MCID per avoided failure. Implementing BMI thresholds alone did not influence the rate of improvements in KOOS-PS, KRQOL, or VR-12. CONCLUSION: Utilizing BMI cutoffs as the sole determinants of TKA ineligibility may deny patients complication-free postoperative courses and clinically important improvements. Shared decision-making supported by predictive tools may aid in balancing the potential benefit TKA offers to obese patients with the potentially increased complication risk and cost of care provision.

What is the Likelihood of Subsequent Arthroplasties after Primary TKA or THA? Data from the Osteoarthritis Initiative.

BACKGROUND: Osteoarthritis is common and debilitating, in part because it often affects more than one large weightbearing joint. The likelihood of undergoing more than one total joint arthroplasty has not been studied in a heterogeneous, multicenter population in the United States. QUESTIONS/PURPOSES: We used prospectively collected data of patients with osteoarthritis from the multicenter Osteoarthritis Initiative (OAI) project to ask (1) What is the likelihood of a subsequent THA or TKA after primary TKA or THA? (2) What risk factors are associated with undergoing contralateral TKA after primary TKA? METHODS: Longitudinally maintained data from the OAI were used to identify 332 patients who underwent primary TKA and 132 patients who underwent primary THA for osteoarthritis who did not have a previous TKA or THA in this retrospective study. OAI was a longitudinal cohort study of knee osteoarthritis conducted at five centers in the United States (Columbus, OH, USA; Pittsburgh, PA, USA; Baltimore, MD, USA; Pawtucket, RI, USA; and San Francisco, CA, USA). In this study, the mean follow-up time was 4.0 ± 2.3 years, with 24% (112 of 464) followed for less than 2 years. The primary outcome was the cumulative incidence of subsequent arthroplasty calculated using the Kaplan-Meier method. Age, BMI, gender, and contralateral Kellgren-Lawrence grade, medial joint space width, and hip-knee-ankle angles were modeled as risk factors of contralateral TKA using Cox proportional hazards. RESULTS: Using the Kaplan-Meier method, at 8 years the cumulative incidence of contralateral TKA after the index TKA was 40% (95% CI 31 to 49) and the cumulative incidence of any THA after index TKA was 13% (95% CI 5 to 21). The cumulative incidence of contralateral THA after the index THA was 8% (95% CI 2 to 14), and the cumulative incidence of any TKA after index THA was 32% (95% CI 15 to 48). Risk factors for undergoing contralateral TKA were younger age (HR 0.95 for each year of increasing age [95% CI 0.92 to 0.98]; p = 0.001) and loss of medial joint space width with a varus deformity (HR 1.26 for each 1 mm loss of joint space width at 1.6 varus [1.06 to 1.51]; p = 0.005). CONCLUSION: Patients who underwent TKA or THA for osteoarthritis had a high rate of subsequent joint arthroplasties in this study conducted at multiple centers in the United States. The rate of subsequent joint arthroplasty determined in this study can be used to counsel patients in similar settings and institutions, and may serve as a benchmark to assess future osteoarthritis disease-modifying interventions. LEVEL OF EVIDENCE: Level III, therapeutic study.

Opioid Use Disorder Is Associated with an Increased Risk of Infection after Total Joint Arthroplasty: A Large Database Study.

BACKGROUND: Recent studies have shown that patients with opioid use disorder have impaired immunity. However, few studies with large patient populations have evaluated the risks of surgical site infection (SSI) and prosthetic joint infection (PJI) with opioid use disorder after total joint arthroplasty (TJA), and there is a lack of evidence for revision TJA in particular. QUESTIONS/PURPOSES: Are patients with opioid use disorder who undergo (1) primary THA, (2) primary TKA, (3) revision THA, or (4) revision TKA at a higher risk of experiencing SSIs 90 days after surgery or PJIs 2 years after surgery than those who do not have opioid use disorder? METHODS: All primary and revision TJAs performed between 2005 and 2014 were identified from the Medicare Analytical Files of the PearlDiver Supercomputer using ICD-9 codes. This database is one of the largest nationwide databases; it comprehensively and longitudinally tracks patients based on all insurance claims rather than particular hospital visits, and has a low error rate (estimated at 1.3%). Boolean command operators were used to form a study group of patients with a history of opioid use disorder before surgery. ICD-9 diagnosis codes 304.00 to 304.02 and 305.50 to 305.52 were used to identify patients with opioid use disorder. Study group patients were matched 1:1 to control participants without opioid use disorder undergoing TJA, according to age, sex, and comorbidity burden (Elixhauser comorbidity index [ECI]). The ECI is comprised of 31 different comorbidities and can be used for large administrative databases. The query yielded a study population of 54,332 patients: 14,944 undergoing primary THA (opioid use disorder: n = 7472), 23,680 undergoing primary TKA (opioid use disorder: n = 11,840), 8116 undergoing revision THA (opioid use disorder: n = 4058), and 7592 undergoing revision TKA (opioid use disorder: n = 3796). The primary outcomes analyzed were SSI at 90 days and PJI at 2 years postoperatively, which were identified with ICD-9 codes. Logistic regression analyses were performed to calculate the risk that an infection would develop in a patient with opioid use disorder compared with the matched control patients without opioid use disorder. RESULTS: Patients with opioid use disorder undergoing primary THA had an increased risk of SSI at 90 days (OR 1.85 [95% CI 1.51 to 2.25]; p < 0.001) and PJI at 2 years (OR 1.66 [95% CI 1.42 to 1.93]; p < 0.001). Compared with matched controls, opioid use disorder patients undergoing primary TKA had an increased risk of SSI at 90 days (OR 1.72 [95% CI 1.46 to 2.02]; p < 0.001) and PJI at 2 years (OR 1.31 [95% CI 1.16 to 1.47]; p < 0.001). Similarly, for revision THAs, there was an increase in 90-day SSIs (OR 1.89 [95% CI 1.53 to 2.32]; p < 0.001) and 2-year PJIs (OR 4.24 [95% CI 3.67 to 4.89]; p < 0.001). The same held for revision TKAs for 90-day SSIs (OR 1.88 [95% CI 1.53 to 2.29]; p < 0.001) and 2-year PJIs (OR 4.94 [95% CI 4.24 to 5.76]; p < 0.001). CONCLUSIONS: After accounting for age, sex, and comorbidity burden, these results revealed that patients with opioid use disorder undergoing TJA were at increased risk of having SSIs and PJIs. Based on these findings, healthcare systems and/or administrators should recognize the increased associated PJI and SSI risks in patients with opioid use disorder and enact clinical policies that reflect these associated risks. Additionally, these findings should encourage surgeons to pursue multidisciplinary approaches to help patients reduce their opioid consumption before their arthroplasty procedure. LEVEL OF EVIDENCE: Level III, therapeutic study.

What Are Risk Factors for Infection after Primary or Revision Total Joint Arthroplasty in Patients Older Than 80 Years?

BACKGROUND: Patients older than 80 years of age form an increasing proportion of the patient population undergoing total joint arthroplasty (TJA). With increasing life expectancy and the success of TJA, orthopaedic surgeons are more likely to operate on patients older than 80 years than ever before. Given that most other studies focus on younger populations, only evaluate primary TJA, or limit patient populations to institutional or regional data, we felt a large-database, nationwide analysis of this demographic cohort was warranted, and we wished to consider both primary and revision TJA. QUESTIONS/PURPOSES: In this study, we sought to investigate the risk factors for surgical site infections (SSIs) at 90 days and periprosthetic joint infections (PJIs) at 2 years after surgery in patients aged 80 years and older undergoing (1) primary and (2) revision lower extremity TJA. METHODS: All patients aged 80 years or older who underwent primary or revision TJA between 2005 and 2014 were identified using the Medicare Analytical Files of the PearlDiver Supercomputer using ICD-9 codes. This database is unique in that it is one of the largest nationwide databases, and so it provides a large enough sample size of patients 80 years or older. Additionally, this database provides comprehensive and longitudinal patient data tracking, and a low error rate. Our final cohort consisted of 503,241 patients (TKA: n = 275,717; THA: n = 162,489; revision TKA: n = 28,779; revision THA: n = 36,256). Multivariate logistic regression models were constructed to evaluate the association of risk factors on the incidences of 90-day SSI and 2-year PJI. Variables such as sex, diabetes, BMI, and congestive heart failure, were included in the multivariate regression models. Several high-risk comorbidities as identified by the Charlson and Elixhauser comorbidity indices were selected to construct the models. We performed a Bonferroni-adjusted correction to account for the fact that multiple statistical comparisons were made, with a p value < 0.002 being considered statistically significant. RESULTS: For primary TKA patients, an increased risk of 90-day SSIs was associated with male sex (OR 1.28 [95% CI 1.25 to 1.52]; p < 0.001), BMI greater than 25 k/m (p < 0.001), and other comorbidities. For primary THA patients, an increased risk of 90-day SSIs was associated with patients with obesity (BMI 30-39 kg/m; OR 1.91 [95% CI 1.60 to 2.26]; p < 0.001) and those with morbid obesity (BMI 40-70 kg/m; OR 2.58 [95% CI 1.95 to 3.36]; p < 0.001). For revision TKA patients, an increased risk of SSI was associated with iron-deficiency anemia (OR 1.82 [95% CI 1.37 to 2.28]; p < 0.001). For revision THA patients, electrolyte imbalance (OR 1.48 [95% CI 1.23 to 1.79]; p < 0.001) and iron-deficiency anemia (OR 1.63 [95% CI 1.35 to 1.99]; p < 0.001) were associated with an increased risk of 90-day SSI. Similar associations were noted for PJI in each cohort. CONCLUSIONS: These findings show that in this population, male sex, obesity, hypertension, iron-deficiency anemia, among other high-risk comorbidities are associated with a higher risk of SSIs and PJIs. Based on these findings, orthopaedic surgeons should actively engage in comanagement strategies with internists and other specialists to address modifiable risk factors through practices such as weight management programs, blood pressure reduction, and electrolyte balancing. Furthermore, this data should encourage healthcare systems and policy makers to recognize that this patient demographic is at increased risks for PJI or SSI, and these risks must be considered when negotiating payment bundles. LEVEL OF EVIDENCE: Level III, therapeutic study.

Joint Preservation Procedures for Osteonecrosis.

Osteonecrosis of the femoral head is characterized by reduced intraosseous blood flow to the subchondral bone. The management of early osteonecrosis usually involves joint preservation procedures to provide pain relief, prevent disease progression, and avoid joint replacement. A thorough clinical evaluation is crucial to identify at-risk patients and allow early intervention with joint preservation. The decision to use one joint preserving method over another is dependent on staging and patient characteristics. Surgeons should have a thorough understanding of the available joint preservation procedures to help determine the optimal treatment modality for their patients.

Thirty-Day Complications in Osteonecrosis Patients Following Total Hip Arthroplasty.

BACKGROUND: Thirty-day complications in osteonecrosis (ON) patients undergoing total hip arthroplasty (THA) are inconsistently reported. Therefore, the purpose of this study is to evaluate (1) the incidence of THA, (2) operative times, (2) length of stay, (3) reoperation rates, (4) readmission rates, and (5) complication rates, in the general vs ON THA populations. We also substratified and compared these cohorts based on ON-specific risk factors. METHODS: Using the National Surgical Quality Improvement Program database, Current Procedural Terminology code 27130, International Classification of Disease, Ninth Edition code 733.42, and a 1:1 propensity score match, a total of 8344 matched ON and non-ON THA patients were identified. ON patients were also substratified based on key risk factors. The above variables were compared between the matched ON and non-ON cohorts as well as for patients with each risk factor using Pearson's chi-square and Student t-tests. RESULTS: The proportion of THAs performed on ON patients decreased by 35% from 2008 to 2015. Mean operative times were constant between the ON and non-ON patients (102 minutes). ON patients had shorter mean length of stay (3.1 vs 3.4 days, P = .002). Of the 17 different 30-day complications evaluated, superficial surgical site infection (1.2% vs 0.6%, P = .004), pneumonia (0.8% vs 0.2%, P = .001), transfusion (15.6% vs 5.4%, P < .001), and readmission (5.1% vs 2.3%, P = .012) were higher among ON patients. ON patients with a history of corticosteroid use, higher American Society of Anesthesiologists score, and smoking were also found to have higher complication rates compared to non-ON patients with the same risk factors. CONCLUSION: This is one of the first studies to compare postoperative THA outcomes between matched ON vs non-ON patients, while also taking into consideration specific risk factors between the cohorts.

Is Iron Deficiency Anemia a Risk Factor for Poorer Outcomes in Primary Total Knee Arthroplasty?

BACKGROUND: Patients undergoing total knee arthroplasty (TKA) commonly have concomitant iron deficiency anemia (IDA). The purpose of this study is to investigate the effect of IDA on (1) total in-hospital lengths of stay (LOS); (2) 90-day readmissions; (3) costs of care; (4) medical complications; and (5) and implant-related complications in patients who underwent primary TKA. METHODS: Patients with and without IDA undergoing primary TKA were identified and matched through a nationwide administrative claims database that yielded 94,053 and 470,264 patients, respectively. Primary outcomes that were statistically analyzed included in-hospital LOS, readmission rates, costs of care, medical complications, and implant-related complications. RESULTS: Patients with IDA had longer in-hospital LOS (4 days vs 3 days; P < .0001), 90-day readmission rates (25.8% vs 16.3%; odds ratio [OR], 1.77; P < .0001), higher day of surgery ($13,079.42 vs $11,758.25; P < .0001), and total global 90-day episode of care costs ($17,635.13 vs $14,439.06; P < .0001) compared to patients who do not have IDA. Furthermore, IDA patients were found to have significantly higher incidence and odds of medical (3.53% vs 1.33%; OR, 2.71; P < .0001) and implant-related (3.80% vs 2.68%; OR, 1.43; P < .0001) complications following primary TKA. CONCLUSION: The effect of IDA on TKA outcomes may make a large impact on healthcare usage. We found that patients with IDA had poorer results in all the outcomes that were measured. Orthopedic surgeons can use this information to evaluate the need for IDA interventions before TKA which may contribute to lower rates of morbidity and mortality in TKA.

Have Venous Thromboembolism Rates Decreased in Total Hip and Knee Arthroplasty?

BACKGROUND: Venous thromboembolism (VTE) is a major cause of morbidity, mortality, and healthcare costs in arthroplasty patients. In an effort to reduce VTEs, numerous strategies and guidelines have been implemented, but their impact remains unclear. The purpose of this study is to compare annual trends in 30-day VTE, deep vein thrombosis (DVT), pulmonary embolism (PE), and all-cause mortality in (1) total hip arthroplasty (THA) and (2) total knee arthroplasty (TKA). METHODS: The American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database identified 363,530 patients who received a TKA or THA from 2008 to 2016. Bivariate analysis was performed to assess the association between the year in which surgery was performed and demographics and comorbidities. Bimodal multivariate logistic regression models for THA and TKA were developed for 2009-2016 using 2008 as a reference. RESULTS: Overall incidence of VTE, DVT, PE, and mortality for THA were 0.6%, 0.4%, 0.3%, and 0.2%, respectively. Based off of multivariate regression VTE, DVT, PE, and mortality rates have shown no significant (P > .05) change from 2008 to 2016 in THA patients. Overall incidence of VTE, DVT, PE, and mortality for TKA were 1.4%, 0.9%, 0.6%, and 0.1%, respectively. Multivariate regression revealed reductions when compared to 2008 for VTEs and DVTs from 2009 to 2016 (P < .05) for TKA patients. A significant reduction in PEs (P = .002) was discovered for 2016, while no significant change was observed in mortality (P > .05). CONCLUSION: Approximately 1 in 71 patient undergoing TKA, and 1 in 167 undergoing THA developed a VTE within 30 days after surgery. Our study demonstrated that VTE incidence rates have decreased in TKA, while remaining stable in THA over the past 8 years. Further research to determine the optimal prophylaxis algorithm that would allow for a personalized, efficacious, and safe thromboprophylaxis regimen is needed. LEVEL OF EVIDENCE: III.

Hospital Volume and Postoperative Infections in Total Knee Arthroplasty.

BACKGROUND: The purpose of this study was to evaluate the associations of hospital volume with revision surgery for infection and superficial incisional infections. METHODS: A review of 12,541 primary total knee arthroplasties (TKAs) at a large integrated health system from 2014 to 2017 was conducted. Sixteen hospitals were classified as low-volume, medium-volume, or high-volume hospitals according to the mean number of TKAs/year (<250, 250-500, and >500, respectively). Thresholds were guided by percentiles and the literature on volume-outcome relationships. Medical records were reviewed for revision surgery for infection and superficial incisional infections during a mean 2-year review period. Multivariate analyses, adjusted for clinical and patient characteristics, were performed to evaluate the association between hospital volume and infection. RESULTS: The overall rate of revision surgery for infection was 0.7% (n = 82), and the overall rate of superficial incisional infection was 2.6% (n = 324). After accounting for potential confounders, hospital volume was not found to have a significant association with revision surgery for infection when comparing high-volume and low-volume hospitals (odds ratio, 1.615; 95% confidence interval, 0.761-3.427; P = .212) as well as when comparing high-volume and medium-volume hospitals (odds ratio, 1.464; 95% confidence interval, 0.853-2.512; P = .166). Moreover, the risk of superficial incisional infection at high-volume hospitals was similar to that at low-volume (P = .107) and medium-volume (P = .491) hospitals. CONCLUSION: Infection outcomes are quality metrics that are frequently used to compare hospitals including those of varying volumes. Using contemporary thresholds, this study found that infection rates after TKA at high-volume hospitals are comparable to low-volume and medium-volume hospitals.

Effects of Estimated Glomerular Filtration Rate on 30-Day Mortality and Postoperative Complications After Total Hip Arthroplasty: A Risk Stratification Instrument.

BACKGROUND: Chronic kidney disease (CKD) is a relatively common comorbidity that has been shown to adversely affect outcomes in total hip arthroplasty (THA), as well as to increase the procedure's total costs. However, the effect of different stages of kidney disease and the association of estimated glomerular filtration rate (eGFR) with perioperative THA complications are less understood. Therefore, the aims of this study were to investigate the relationships between eGFR, both as a categorical and continuous variable and 30-day outcomes and complications. METHODS: The National Surgical Quality Improvement Program database was used to identify 101,925 primary THAs between January 1, 2008, and December 31, 2016. The following outcomes were assessed: 30-day mortality, 30-day major complications, 30-day minor complications, specific complications, and discharge disposition. To evaluate the effect of eGFR status on outcomes and complication, multivariate regression models were created to adjust for differences in patient demographics and comorbidities. In addition, multivariate spline regressions were developed to assess the nonlinear relationships between eGFR as a continuous variable and the outcomes of interest. RESULTS: Our study revealed that as eGFR decreases to <30 mL/min/1.73 m2, there is an increased risk for mortality and nonhome discharge (P < .05). There was an increased risk for any major complication and any minor complication as well as several specific medical complications such as transfusion and myocardial infarction (P < .05) for an eGFR of <60 mL/min/1.73 m2. Patients' eGFR had a nonlinear relationship with mortality (P = .0001), any major complication (P < .001), and any minor complication (P < .001), as well as a number of other specific medical complications. Once the eGFR, <60 mL/min/1.73 m2 the increase was exponential for mortality, major complications, and minor complications. For example, mortality increased of 900% for <15 mL/min/1.73 m2 or on dialysis, 600% for 15 to 30 mL/min/1.73 m2 and 50% for 30 to 60 mL/min/1.73 m2. Similarly, nonlinear relationships were discovered between eGFR and nonhome discharge (P < .001). CONCLUSION: Patients with lower eGFR, and in particular those with <30 mL/min/1.73 m2, are more likely to sustain medical complications and have 6 to 9 times higher mortality than patients with normal eGFR. THA patients with CKD should be appropriately counseled and advised on the risk of postoperative complications by using eGFR as a screening tool.

Patients Who Have Cannabis Use Disorder Have Higher Rates of Venous Thromboemboli, Readmission Rates, and Costs Following Primary Total Knee Arthroplasty.

BACKGROUND: Studies have shown that cannabis can interfere with hematological parameters and platelet morphology. The purpose of this study is to investigate whether patients with cannabis use disorder undergoing primary total knee arthroplasty (TKA) have higher rates of (1) venous thromboemboli (VTEs); (2) readmissions; and (3) costs. METHODS: Study group patients undergoing primary TKA were identified from a large, nationwide database. Patients who had a history of VTEs, deep vein thromboses (DVTs), pulmonary emboli (PEs), and coagulopathies before their TKA were excluded. Study group patients were matched to controls in a 1:4 ratio by age, sex, a comorbidity index, and medical comorbidities. The query yielded 18,388 patients (cannabis = 3680; controls = 14,708). Outcomes analyzed included rates of 90-day VTEs, DVTs, and PEs, in addition to 90-day readmissions and costs. A P value less than .01 was considered statistically significant. RESULTS: Patients who have cannabis use disorder were found to have significantly higher incidence and odds (2.79% vs 1.78%; odds ratio [OR], 1.58; P < .0001) of VTEs, DVTs (2.41% vs 1.44%; OR, 1.68; P < .0001), and PEs (0.97% vs 0.62%; P = .01). Readmissions were significantly higher (27.03% vs 23.18%; OR, 1.22; P < .0001) in patients who have cannabis use disorder. Patients with cannabis use disorder have significantly higher day of surgery ($14,024.88 vs $12,127.49; P < .0001) and 90-day costs ($19,155.45 vs $16,315.00; P < .0001). CONCLUSION: This study found that patients who have a cannabis use disorder have higher rates of thromboembolic complications, readmission rates, and costs following primary TKA compared to a matched cohort.

The Effect of Bladder Catheterization on Ambulation and Venous Thromboembolism Following Total Knee Arthroplasty: An Institutional Analysis.

BACKGROUND: Although intermittent catheters are immediately removed, indwelling catheterization may lead to decreased ambulation and participation in physical therapy, critical components to post-total knee arthroplasty (TKA) management. Therefore, this study aimed to compare the effect of catheterization treatments on (1) postoperative ambulation distances, (2) deep vein thromboses (DVTs), and (3) pulmonary emboli (PEs) following TKA. METHODS: A total of 9123 prospectively collected primary TKA patients were assessed based on postoperative catheter status. Patient demographics, Charlson Comorbidity Indices, body mass indices, DVT prophylaxes, first ambulation distances, DVTs, and PEs were collected at approximately mean 12 months of follow-up. Univariate and multivariate analyses were performed with independent t-tests and multiple linear regression models in order to compare catheterization techniques. RESULTS: There were 1193 patients who had urinary retention and treated with either indwelling only (62%, n = 734), both indwelling and intermittent catheterizations (13%, n = 160), or intermittent only (25%, n = 299). Multivariate analyses found that indwelling catheter-only use had an 11% decrease in ambulation distance (P < .001). Additionally, the indwelling catheterization-only group was found to be at increased risk of DVTs (odds ratio 2.605, P < .001), even after controlling for DVT prophylaxes (odds ratio 2.807, P < .001). CONCLUSION: This study showed that the use of an indwelling catheter for treatment of urinary retention significantly decreased TKA patient ambulation distance and subsequently increased the risk for DVTs. This information is important as we would recommend the treatment with intermittent catheterization rather than indwelling catheters to decrease the risk of immobilization and postoperative DVTs.

The Effects of Opioid Use on Thromboembolic Complications, Readmission Rates, and 90-Day Episode of Care Costs After Total Hip Arthroplasty.

BACKGROUND: The purpose of this study was to investigate whether opioid use disorder (OUD) patients are at greater odds than non-opioid use disorder (NUD) patients in developing (1) thromboembolic complications; (2) readmission rates; and (3) costs of care. METHODS: All patients with a 90-day history of OUD before total hip arthroplasty (THA) were identified from a national database. Patients were matched 1:5 to controls by age, gender, Elixhauser Comorbidity Index scores, and high-risk medical comorbidities, yielding 38,821 patients with (n = 6398) and without (n = 31,883) OUD. Multivariate logistic regression analyses were performed to compare the risks of developing venous thromboembolism (deep vein thrombosis and/or pulmonary embolism) 90 days after the index procedure, 90-day readmission rates, and total global 90-day episode of care costs. RESULTS: Patients with a history of OUD were found to be at greater risk for 90-day venous thromboembolisms (2.38 vs. 1.07%; OR: 2.25, 95% CI: 1.86-2.73, P < .0001) compared with matched NUD patients. Specifically, OUD patients were at greater risk for both deep vein thromboses (2.13 vs. 0.87%; OR: 2.46, 95% CI: 2.00-3.03, P < .001) and pulmonary embolism (0.61 vs. 0.27%; OR: 2.24, 95% CI: 1.53-3.27, P < .0001). In addition, patients with OUD were at an increased risk for 90-day readmission (28.68 vs. 22.62%; OR: 1.37, 95% CI: 1.29-1.46, P < .0001) compared with controls. Primary THA patients with OUD incurred a 14.72% higher cost of care ($20,610.65 vs. $17,964.58) compared with NUD patients. CONCLUSION: These findings demonstrate that primary THA patients with a history of OUD are at greater risks for thromboembolic complications, readmissions, and higher costs of care in the 90-day postoperative period.

Are We Treating Similar Patients? Hospital Volume and the Difference in Patient Populations for Total Knee Arthroplasty.

BACKGROUND: Early findings of superior total knee arthroplasty (TKA) outcomes at high volume centers have been thought to have led to distinct referral patterns. However, the effect of these selective referral processes has not been well assessed. Therefore, this study compared the characteristics of primary TKA patients at high, intermediate, and low volume hospitals. METHODS: A total of 12,541 primary TKA patients were stratified into risk groups based on age (>65 years), body mass index (>40), and Charlson Comorbidity Index (≥4). Hospitals were classified as low, intermediate, or high volume based on mean annual TKA volumes (<250, 250-499, and >500). Multivariate logistic regression models evaluated the relationship between baseline patient characteristics and hospital volume. RESULTS: There was a greater percentage of high risk patients at high volume (19%, n = 853) compared to those at intermediate (16%, n = 899) or low volume (17%, n = 444) hospitals (P < .001). Patients with a body mass index >40 were more likely to be treated at high compared to intermediate (odds ratio [OR] 1.4, 95% confidence interval [CI] 1.2-1.6, P < .001) and low volume centers (OR 1.4, 95% CI 1.2-1.7, P < .001). Patients with Charlson Comorbidity Index scores ≥4 were also more likely be treated at high compared to intermediate (OR 1.5, 95% CI 1.3-1.6, P < .001) or low (OR 1.2, 95% CI 1.0-1.4, P = .002) volume centers. CONCLUSION: This study found that TKA patients at high volume centers have significantly different baseline characteristics compared to those at lower volume centers. This study highlights the importance of considering hospital volume status and the associated disparity in the preoperative risk of patients when comparing primary TKA outcomes between centers.

Does Intermittent Catheterization Compared to Indwelling Catheterization Decrease the Risk of Periprosthetic Joint Infection Following Total Knee Arthroplasty?

BACKGROUND: Catheterization for the prophylaxis against or treatment for urinary retention commonly occurs after total knee arthroplasty (TKA). Recent studies have questioned the use of the indwelling catheterization, especially in its potential role as a nidus for infection. We are still unsure of its downstream effects on periprosthetic joint infections (PJIs). Therefore, this study aimed to compare the risks of postoperative PJI following intermittent vs indwelling catheterization after TKA. METHODS: Between 2017 and 2019, 15 hospitals in a large health system collected data on patients undergoing TKA. Patient treatments with indwelling catheter only, intermittent straight catheter only, and both indwelling and intermittent straight catheterizations were recorded. Patient demographics, comorbidities, body mass indices, and PJIs were collected from time of surgery to time of data collection at mean 14 months of follow-up. Univariate and multivariate analyses were performed with independent t-tests and multiple linear regression models to compare catheterization treatment types. RESULTS: A total of 9123 TKAs were performed, with patients receiving indwelling catheter only (62%, n = 734), intermittent straight catheter only (25%, n = 299), or both indwelling and intermittent catheterizations (13%, n = 160). Univariate analyses showed that PJIs occurred in 1.1% of no-catheter patients and 2.3% of patients treated with bladder catheterization (P = .002). Using multivariate analyses, indwelling catheter use (odds ratio [OR] 2.647, P < .001), diabetes (OR 1.837, P = .005), and peripheral vascular disease (OR 2.372, P = .046) were found to have a statistically significant increased risk for PJIs. The use of intermittent straight catheterization (OR 1.249, P = .668) or both indwelling and intermittent (OR 1.171, P = .828) did not increase the risk for PJIs. CONCLUSION: Urinary bladder catheterization is commonly required for prophylaxis against or treatment for urinary retention following TKA. The use of a urinary catheter can provide a potential nidus for infection in these patients. This study found that indwelling catheterization, but not intermittent catheterization, was associated with an increased risk for PJI. Surgeons should therefore limit the duration of catheterization in an effort to decrease the risk for PJI.

The Cumulative Effect of Substance Abuse Disorders and Depression on Postoperative Complications After Primary Total Knee Arthroplasty.

BACKGROUND: Substance abuse disorder (SUD), alcohol abuse disorder (AUD), and depression have been identified as independent risk factors for complications after total knee arthroplasty (TKA). However, these mental health disorders are highly co-associated, and their cumulative effect on postoperative complications have not been investigated. Therefore, this study aimed to determine if patients who have more than one mental health disorder (SUD, AUD, or depression) were at an increased risk for postoperative complications following TKA. METHODS: A total of 11,403 TKA patients were identified from a prospectively collected institutional database between January 1, 2017 and April 1, 2019. Patients who had depression, SUD, and AUD were separated into 7 mental health subgroups including each of these diagnoses alone and their combined permeations. Patient demographics, body mass indices, medical comorbidities, and 15 postoperative complications were collected. Univariate analyses were performed using independent Student's t-tests. Multivariate analyses were then performed to identify odds ratios (ORs) for mental health disorders subgroups associated with complications. RESULTS: We found a total of 2073 (18%) patients diagnosed with either SUD (4%), AUD (0.6%), or depression (12%). Univariate analyses showed that depression was associated with mechanical failures (P < .001). SUD was associated with periprosthetic joint infection (PJI) (P < .001), wound complications (P = .022), and aseptic loosening (P = .007). AUD was associated with PJI (P < .001) and deep vein thromboses (P = .003). Multivariate analyses found that AUD (OR: 19.419, P < .001) and SUD (OR:3.693, P = .010) were independent risk factors for PJI. Compared with SUD alone, patients with depression plus SUD were found to have a 4-fold (OR: 13.639, P < .001) and 2-fold (OR:4.401, P = .021) increased risk for PJI and cellulitis, respectively. CONCLUSIONS: Patients who had depression, SUD, or AUD were at increased risk for postoperative complications following primary TKA. When patients have more than one mental health diagnosis, their risk for complications was amplified. The results of this study can help identify those patients who are at greater risk of postoperative complications to enable improved preoperative optimization and patient education.

Perioperative Outcomes and Complications After Primary Total Hip Arthroplasty in Patients With Disproportionately Short Stature: A Matched Cohort Analysis.

BACKGROUND: This study compared (1) perioperative outcomes, (2) postoperative complications, and (3) reoperation rates after primary total hip arthroplasty (THA) between short stature patients and matched control patients. METHODS: A review of primary THA patients from 2012 to 2017 using an institutional database was conducted. This yielded 12,850 patients of which 108 were shorter than 148 cm. These patients were matched 1:1 by age (P = .527), gender (P = .664), and body mass index (P = .240) to controls. The final study population with minimum 1-year follow-up that was included for analysis comprised 47 patients in the short stature cohort and 57 patients in the control cohort. The following outcomes/complications were compared: operative times, lengths of stay (LOSs), intraoperative fractures, minor complications, 90-day readmissions, and revisions. RESULTS: Operative times were significantly longer in the short stature cohort than in the matched control cohort (133 ± 65 minutes vs 104 ± 30 minutes, P = .005). In addition, hospital LOS was slightly longer in the short stature group than in the matched control groups (3.2 ± 1.5 days vs 2.6 ± 1.0, P = .017). Rates of intraoperative fractures (P = 1.000), minor complications P = .406), 90-day readmissions (P = .5000), and revision (P = .202) were similar between the short stature and control cohorts. CONCLUSION: Patients with disproportionately short stature had longer operative times and slight longer LOS. However, complication and readmission rates were similar. Future studies with larger sample sizes are warranted to confirm these findings and further evaluate implant survivorship in this unique THA patient population.

Estimated Glomerular Filtration Rate as a Risk Stratification Tool for Early Complications in Revision Total Hip and Knee Arthroplasty.

BACKGROUND: Establishing an association between postoperative outcomes and the spectrum of renal function would allow for more informed decisions to manage surgical risks and improved patient-specific care. Estimated glomerular filtration rate (eGFR) can be calculated from standard prescreening measurements to gauge renal function. This work investigates the effect of eGFR, as a continuous and categorical variable, on mortality and major and minor complications in patients undergoing revision total knee and hip arthroplasty. METHODS: 25,056 patients having undergone revision total hip and knee arthroplasty from 2013 to 2016 were identified using the National Quality Improvement Program database. The investigated outcomes included 30-day mortality, major complications, and minor complications. Multivariate regression models were created to evaluate the effect of eGFR on the outcomes of interest. Multivariate spline regressions were generated to assess for nonlinear relationships between eGFR as a continuous variable and the outcomes. RESULTS: Our study revealed that as eGFR decreased <60 mL/min/1.73 m2, mortality (P = .0001), any major complication (P < .001), and any minor complication (P < .001) increased. Patients with eGFR 15-30 mL/min/1.73 m2 had increased risk for mortality (P = .033). There was an increased risk for any major complication at an eGFR 30-60 and <15 mL/min/1.73 m2, (P < .05). There was an increased risk of minor complications for those with hyperfiltration and <60 mL/min/1.73 m2. CONCLUSION: Patients with lower preoperative eGFR generally display an increased risk for complications after revision total hip and knee arthroplasty. Proper consideration should be given to this patient population before surgical intervention to allow for preventative measures to be taken to improve patient outcomes.