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.

An Updated Review on Layered Closure Techniques for Total Hip Arthroplasty.

INTRODUCTION: One of the main concerns with total hip arthroplasty is the development of periprosthetic joint infections (PJIs). Appropriate wound closure can contribute to the prevention of PJIs with a watertight closure effectively sealing the implant from the outside. It is important to continuously investigate which materials as well as techniques are potentially the most efficacious and cost effective for wound closure. Therefore, the purpose of this review article was to critically appraise the current total hip arthroplasty wound closure materials and techniques as reported in the literature. Specifically, we evaluated: 1) fascial approximations; 2) subdermal closures; 3) subcuticular and skin closures; 4) wound dressings; as well as 5) capsular and short external rotator repairs. MATERIALS AND METHODS: A literature search was performed using the PubMed database from inception to February 2022. The query consisted of terms including "hip, arthroplasty, wound, closure, capsular closure, fascial closure, subcutaneous closure, and skin closure." References from selected texts were also reviewed for inclusion. Only manuscripts written in the English language were included for final analysis. A systematic review was performed for the five topics: 1) fascial approximations; 2) subdermal closures; 3) subcuticular and skin closures; 4) wound dressings; as well as 5) capsular and short external rotator repairs. Additionally, a meta-analysis was performed on the closing time of fascial approximations. RESULTS: The current literature supports performing a layered closure of the wound by approximating the fascial layers, which can help close any empty spaces. The techniques for closure at this layer seem to be equal regarding wound complications between running knotless barbed sutures versus interrupted throws; however, knotless sutures have the potential of a quicker closure time. A total of three out of four reports and the meta-analyses demonstrated that wound closure time can be reduced with barbed sutures, along with decreased number of sutures required as also shown by three out of four reports. The most superficial layers, subcuticular and skin, can be closed with either sutures, staples, or skin adhesives, all of which appear to have adequate outcomes. A report found that patients who had skin closure with barbed suture had faster time to a dry postoperative wound and lower rates of delayed discharge. For the overlying dressing, an occlusive and absorbent dressing can both protect the wound as well as collect any residual wound drainage. Two reports found increased dryness, decreased wound drainage, and decreased rates of delayed wound healing with use of 2-octyl cyanoacrylate topical adhesive with flexible self-adhesive polyester mesh dressings. If the capsule and short external rotators are taken down during the approach, repairing these can potentially help increase postoperative hip stability as well as decrease dislocation rates. CONCLUSION: The variety of materials and techniques available to close a THA wound allows surgeons to tailor closure to be patient specific. In general, the authors recommend performing layered closures from the capsule and short external rotators (if taken down during the approach), fascial layer closure with either a running knotless suture, subcutaneous closure either with the same knotless suture as the fascial layer brought more superficially, or with simple interrupted sutures to tack down any empty space, as well as finally subcuticular and skin sutures with a skin adhesive glue overtop. The skin adhesive can help provide an extra layer, particularly in active patients.

Management of Refractory Pain After Total Joint Replacement.

PURPOSE OF REVIEW: Chronic pain after total joint replacement (TJA), specifically total knee replacement (TKA), is becoming more of a burden on patients, physicians, and the healthcare system as the number of joint replacements performed increases year after year. The management of this type of pain is critical, and therefore, understanding the various modalities physicians can use to help patients with refractory pain after TJA is essential. RECENT FINDINGS: The modalities by which chronic pain can be successfully managed include genicular nerve radioablation therapy (GN-RFA), neuromuscular electrical stimulation (NMES), transcutaneous electrical nerve stimulation (TENS), and peripheral subcutaneous field stimulation (PSFS). Meta-analyses and case reports have demonstrated the effectiveness of these treatment options in improving pain and functional outcomes in patients with chronic pain after TKA. The purpose of this paper is to review and synthesize the current literature investigating the different ways that refractory pain is managed after TJA, with the goal being to provide treatment recommendations for providers treating these patients.

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.

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.

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.

The Effect of Bladder Catheterization Technique on Postoperative Urinary Tract Infections After Primary Total Hip Arthroplasty.

BACKGROUND: Urinary bladder catheters are potential sources of infection after total hip arthroplasty (THA). Therefore, the goal of this study was to determine if intermittent catheterization provides a decreased risk of postoperative urinary tract infections (UTIs) compared with indwelling catheterization in THA patients. METHODS: Patients undergoing THA at 15 hospitals within a large health system were prospectively collected between 2017 and 2019 and then stratified based on catheterization technique: no-catheter; indwelling catheter-only; intermittent catheter-only; and both intermittent and indwelling catheter. Patient demographics, medical comorbidities, anesthesia types, and postoperative UTIs were assessed. Independent Student t-tests were used to perform univariate analyses for the catheterization groups. Multiple linear regression models were used to compare the different groups while controlling for confounding variables. RESULTS: There were a total of 7306 THA patients recorded with 5513 (75%) no-catheter, 1181 (16%) indwelling catheter-only, 285 (3.9%) intermittent catheter-only, and 327 (4.5%) indwelling and intermittent catheterization patients. A total of 580 patients experienced postoperative UTI. Urinary bladder catheterization increased the risk of postoperative UTIs (P < .001) in univariate analyses. Multiple linear regression models showed that indwelling catheter-only (OR: 2.178, P < .001), intermittent catheterization (OR: 1.975, P = .003), and both indwelling and intermittent (OR: 2.372, P = .002) were more likely to experience UTIs compared with no catheters. CONCLUSION: This study found that patients treated with indwelling catheterization, with or without preceding intermittent catheterization, were significantly more likely to experience UTIs. Therefore, in an effort to decrease the risk of UTIs, THA patients experiencing postoperative urinary retention should be treated with intermittent catheterization.

Have We Actually Reduced Our 30-Day Short-Term Surgical Site Infection Rates in Primary Total Hip Arthroplasty in the United States?

BACKGROUND: The purpose of this study is to track the 30-day postoperative annual rates and trends of (1) overall, (2) deep, and (3) superficial surgical site infections (SSIs) following total hip arthroplasty (THA) using a large nationwide database. METHODS: The National Surgical Quality Improvement Program database was queried for all THA cases performed between 2012 and 2016. After an overall 5-year correlation and trends analysis, univariate analysis was performed to compare the most recent year, 2016, with the preceding 4 years. Correlation coefficients and chi-squared tests were used to determine correlation and statistical significance. RESULTS: The lowest incidence of SSIs was in the most recent year, 2016 (0.81%), while the greatest incidence was in the earliest year, 2012 (1.12%), marking a 31% decrease (P < .01). The lowest rate was in the most recent year, 2016 (0.23%), marking a 26% decrease from 2012. The lowest superficial SSI incidence occurred in the most recent year, 2016 (0.58%), while greatest incidence was in 2012 (0.83%), marking a 31% decrease over time (P < .05). There was an inverse correlation among overall, deep, and superficial SSI rates with operative year. CONCLUSION: The findings from this study suggest a decreasing trend in SSIs within 30 days following THA. Furthermore, deep SSIs, which can pose substantial threats to implant survivorship, have also decreased throughout the years. These results highlight that potentially through improved medical and surgical techniques, we are winning the fight against short-term infections, but that more can still be done.

Operative Times Can Predict and Are Correlated With Lengths-of-Stay in Primary Total Knee Arthroplasty: A Nationwide Database Study.

BACKGROUND: The specific influence of operative times on lengths-of-stay (LOS) has not been well assessed and is therefore an important topic of evaluation for multiple reasons, including potential economic implication. The purpose of this study is to (1) identify predictors of longer operative times; (2) identify predictors of longer LOS; and (3) evaluate the effects of operative times on LOS in primary total knee arthroplasty (TKA). METHODS: The National Surgical Quality Improvement Program database was queried for primary TKAs performed between 2008 and 2016, yielding 225,344 cases. Multivariate analysis was performed to determine the effect of operative times on LOS after adjusting for patient factors. Univariate analyses were performed with 1-way analysis of variance (ANOVA), linear regression, and independent sample t-tests where appropriate. Multivariate analysis was performed with a multiple linear regression model adjusted for patient age, sex, and body mass index (BMI). RESULTS: The mean operative time was 93 ± 35 minutes and the mean LOS was 3 ± 3 days. Young age, male sex, and obesity were predictors of longer operative times (P < .001). Similarly, there were significant associations of age, sex, and BMI with LOS (P < .001). Increasing 30-minute operative time intervals were associated with increasing LOS (P < .001). Longer operative times had significant associations with longer LOS even after adjusting for patient factors (ß = 0.076, SE < 0.001, P value < .001). Out of all study covariates, operative times had the greatest effect on LOS. CONCLUSION: This study provides unique insight by directly correlating operative times to LOS in over 200,000 TKAs. The results from this study indicate that there is a strong correlation between operative times and LOS, so that operative time had a greater association than age, sex, and BMI with postoperative TKA LOS.

Does Time Spent in the Post-Anesthesia Care Unit Affect Hospital Lengths of Stay following Primary Total Knee Arthroplasty?

Given the current healthcare economic environment, substantial efforts have been made to help streamline the in-hospital care for total knee arthroplasty (TKA) patients. While potential cost-reducing factors have been identified in the literature, analyses specifically considering post-anesthesia care unit (PACU) lengths of stay (LOS) are lacking. Therefore, the purpose of this study was to identify factors associated with (1) longer PACU LOS as well as (2) longer Hospital LOS. Prospectively collected TKA data from seven participating hospitals within a large health system were evaluated for patient demographics, body mass indices, Charlson Comorbidity Indices (CCI), surgeon volumes/training, admission types, anesthesia types, PACU LOS, and overall hospital LOS. Complete data was available for 1,690 patients (1,082 females, mean age: 67 years). Univariate and multivariate analytical models were constructed to identify which factors were predictive of longer PACU and overall hospital LOS. Same-day admissions, higher volume surgeons (≥ 100 cases per year), fellowship-trained arthroplasty surgeons, and longer operative times were associated with longer PACU LOS (p < 0.05). Multivariate analyses found age more than or equal to 65 years (ß= 0.124) and CCI more than or equal to 3 (ß= 0.088) to be associated with longer hospital LOS (p < 0.001). Operative times, PACU LOS, and procedure times (operative time plus PACU LOS) were not associated with longer hospital LOS (p > 0.05). These data identify associative factors for PACU LOS, as well as the influence of time spent in the PACU on overall hospital LOS. Interestingly, this analysis revealed that patients of arthroplasty fellowship-trained and higher-volume surgeons had longer PACU LOS; however, this could be explained by the observation that these particular surgeons tend to perform more complex deformity cases. Also of importance, increased PACU LOS, meaning the patient spent more time in a high-monitored setting immediately after surgery, did not necessarily confer a longer overall hospital LOS. Based on these data, it may be more beneficial to identify alternate sources than time spent in the operating room or PACU to potentially help reduce overall hospital LOS. LEVEL OF EVIDENCE: II, prospective cohort.

Annual Nationwide Infection Trends for Revision Total Knee Arthroplasty.

Several recent intraoperative and wound management techniques have been developed and implemented in the United States over the past decade; however, it is unclear what the effects of these newer modalities have on reducing surgical site infection (SSI) rates. Therefore, the purpose of this study was to track the annual rate and trends of (1) overall, (2) deep, and (3) superficial SSIs following revision total knee arthroplasty (TKA). The National Surgical Quality Improvement Program database was queried for all revision TKA cases performed between 2011 and 2016, which yielded 9,887 cases. Cases with superficial and/or deep SSIs were analyzed separately and then combined to evaluate overall SSI rates. After an overall 6-year correlation and trends analysis, univariate analysis was performed to compare the most recent year, 2016, with the preceding 5 years. Correlation coefficients and chi-square tests were used to determine correlation and statistical significance. No significant correlations between combined, deep, and/or superficial SSI rates and year were noted (p > 0.05). The lowest overall SSI incidence was in 2012 (1.16%), while the greatest incidence was in 2014 (1.76%). The deep SSI incidence over the 6 years was 0.67% (66 out of 9,887 cases). Deep SSI rate decreased by 10% in 2016 compared with 2011 (0.50 vs. 0.56%, p > 0.05). In this 6-year period, 94 cases out of 9,887 were complicated by a superficial SSI, an incidence of 0.95%. The lowest superficial SSI incidence occurred in 2015 (n = 17, 0.77%). Overall, the incidence of SSIs in revision TKA has remained fairly low with some annual variance, indicating room for improvement. These variations likely as revision surgeries can be more complex and have several associated confounding factors influencing outcomes, when compared with primary cases. Further research is needed to identify revision-specific strategies to reduce the risk of surgical site infections.

Can the Caprini score predict thromboembolism and guide pharmacologic prophylaxis after primary joint arthroplasty?

AIMS: Venous thromboembolism (VTE) has a 30-day mortality rate of between 10 and 30%. The Caprini score is a VTE risk assessment model, which assigns points to 20 past medical history and current health factors. We hypothesized that the Caprini score could predict VTE incidence and recommend prophylaxis following total joint arthroplasty. PATIENTS AND METHODS: We performed a retrospective review of prospectively collected institutional data identifying Caprini scores on 2155 primary hip (n = 840) and knee (n = 1315) arthroplasties. Surgeons were blinded to Caprini scores when prescribing VTE prophylaxis. Patients were separated into prophylaxis groups receiving Aspirin (81 mg BID or 325 mg BID) or other (Rivaroxaban, Warfarin, Enoxaparin, Apixaban, Dabigatran, Heparin). Univariate, multivariate, and Cohen's effect size analyses assessed the predictive power of the Caprini score on VTE incidence. RESULTS: The mean Caprini score was 9.49 (5-25). A majority, 83% (1792) of patients were in the Aspirin group, and 17% (363) in the other group. Other prophylaxis patients had statistically significantly higher Caprini scores (10 vs. 9, p < 0.0001). Twenty-five (1.2%) patients developed VTE. Controlling for prophylaxis, higher Caprini scores increased VTE risk, but this wasn't statistically significant (p = 0.16). Multivariate analysis showed a non-significant effect for patients with BMIs >40 or Caprini scores ≥11 to predict VTE incidence in the Aspirin or other prophylaxis groups (p = 0.52 and p = 0.15 respectively). Cohen's effect size was small, comparing Caprini scores in patients who had and had not had a VTE in both Aspirin and other prophylaxis groups (Cohen's d = 0.25 and d = 0.16 respectively). CONCLUSION: Surgeons rely on stronger pharmacologic prophylaxis for a select high risk group of their primary lower extremity total joint arthroplasty patients. When controlling for prophylaxis, the Caprini score had a small effect size and did not have the predictive power necessary to guide treatment.

Outcomes of Cementless-Backed Patellar Components.

Because of the early follow-up positive outcomes with cementless fixation, continued evaluations need to be performed to ensure longer-term efficacy. Additionally, although many studies report on the results of femoral and tibial component fixation, few studies report specifically on patellar outcomes. Therefore, the purpose of this study was to report on the: (1) implant survivorship; (2) complications; and (3) radiographic outcomes in a large cohort of patients who received cementless total knee arthroplasties (TKAs), with particular attention to the patellar component. A total of 261 patients who underwent cementless TKA by a single, high-volume academic surgeon were studied. Patients had a mean age of 66 years and were distributed between 192 women (74%) and 69 men. All patients received the same cementless tibial, femoral, and patellar components. Mean follow-up period was 4.5 years (range, 4-5 years). Primary outcomes evaluated included all postoperative complications, with particular emphasis on the patellar component. Only one patellar loosened leading to a patellar aseptic loosening rate of 0.3% (1 of 261). The one patellar loosening was the component being dislodged after a manipulation under anesthesia (MUA) at 6 weeks. This was revised to a cemented component and the patient is doing well 4 years later. A second patient experienced a patellar tendon rupture, later surgically repaired. Another patient sustained a patella fracture that was managed nonoperatively. The fracture healed by 1 year and the patient continued to have an otherwise successful outcome, now at 2 years follow-up. No progressive radiolucencies, subsidence, or changes in initial postoperative axial alignment were observed at final follow-up. The results from this study highlight a 98% success rate at mean 4.5 years follow-up in a large cohort of patients with a diverse spread of demographic details. Specific to the patella, only one patient experienced an adverse event, which was managed nonoperatively. Therefore, based on this data, patellar fixation in cementless TKA can be considered a safe technique.

The effect of operative time on in-hospital length of stay in revision total knee arthroplasty.

BACKGROUND: Revision total knee arthroplasty (TKA) is associated with increased rates of infections, readmissions, longer operative times, and lengths-of-stay (LOS) compared to primary TKA. Additionally, increasing operative times and prolonged postoperative LOS are independent risk factors for these postoperative complications in lower extremity total joint arthroplasty (TJA). This has led to an increased effort to reduce these risk factors in order to improve patient outcomes and reduce cost. However, the relationship between operative time and LOS has not been well assessed in revision arthroplasty. Therefore, the purpose of this study was to: (I) identify predictors of longer operative times; (II) identify predictors of longer LOS; and (III) evaluate the effects of operative time, treated as both a categorical variable and a continuous variable, on LOS after revision TKA. METHODS: The NSQIP database was queried for all revision TKA cases (CPT code 27487) between 2008 and 2016 which yielded 10,604 cases. Mean operative times were compared between patient demographics including age groups, sex, and body mass indexes (BMIs). To determine predictors of LOS, mean LOS were also compared between patient demographics in the same groups. To assess the correlation of operative time on LOS, the mean LOS for 30-minute operative time intervals were compared. Univariate analysis was performed with one-way analysis of variance (ANOVA) and t-tests. A multivariate analysis with a multiple linear regression model was performed to evaluate the association of LOS with operative times after adjusting for patient age, sex, and BMI. RESULTS: The mean LOS for revision TKA was 4 (±3) days. Further analysis showed that young age is associated with increased LOS (P<0.01). An analysis of operative times showed positive correlations with young age, BMI greater than 30 and male sex (P<0.05). The mean LOS of revision TKA patients was found to increase with increasing operative time in 30-minute intervals (P<0.001). Multivariate analysis showed that longer operative times had significant associations with longer LOS even after adjusting for patient factors (ß=0.102, SE =0.001, P<0.001). These results also showed that out of all of the study covariates, operative times had the greatest effect on LOS after revision TKA. CONCLUSIONS: Revision TKA is a complex procedure, often requiring increased operative times compared to primary TKA. This study provides unique insight by correlating operative times to LOS in over 10,000 revision TKAs from a nationwide database. Our results demonstrate that out of all the study covariates (age, sex, and BMI), operative times had the greatest effect on LOS. The results from this study indicate that less time spent in the operating room can lead to shorter LOS for revision TKA patients. This relationship further underscores the need for improved preoperative planning and intra-operative efficiency in an effort to decrease LOS and improve patient outcomes.

Not all primary total hip arthroplasties are equal-so is there a difference in reimbursement?

BACKGROUND: Relative value units (RVUs) are a physician reimbursement model based on the effort required, or value, in providing a procedure or service for a patient. Procedures such as conversion total hip arthroplasties (THAs) can be compared to primary THAs, but many studies have revealed increased difficulties in conversion cases. Despite the increased time and effort for conversion THA, it is unknown if this is reflected in the RVU compensation model. Therefore, the purpose of this study was to compare the: (I) mean operative times; (II) mean RVUs; (III) RVU/minute for primary and conversion THAs; and (IV) perform an individualized idealized surgeon annual cost difference analysis. METHODS: A total of 103,702 primary THA patients were identified using CPT code 27130 and 2,986 conversion THA patients were identified using CPT code 27132 using the National Surgical Quality Improvement Program (NSQIP) database. The mean RVUs, operative times (minutes), and RVU/minute were calculated and compared. An annualize cost analysis of dollar amounts per case, day, and the year was also performed. RESULTS: The mean operative times for the primary and conversion THA cohorts were 94 vs. 146 minutes (P<0.001) and mean RVUs were 21.24 vs. 25.68 (P<0.001). Interestingly, the mean RVU per minute was higher for the primary THA compared to the conversion THA groups (0.26 vs. 0.21, P<0.001). Annualized cost analysis revealed a potential $173,529 difference from performing primary vs. conversion THAs. CONCLUSIONS: Even though conversion THA can be considered to a more complex and demanding procedure, based on RVUs per minute of surgery, orthopaedic surgeons are reimbursed better for primary THA cases. This data could be used by orthopaedic surgeons to administer their practices better to yield the highest return on time.

A 6-year trends analysis of infections after revision total hip arthroplasty.

BACKGROUND: Substantial efforts have been made to reduce the risk of infection after total hip arthroplasty (THA), including pre-operative patient optimization, skin preparation with alcohol-based solutions, perioperative antibiotics, and minimizing wound drainage with novel sutures and dressings. While these approaches have been effective in primary THA, their effects on revision THA to improve surgical site infection (SSI) rates are less clear. Therefore, the purpose of this study was to identify the annual rates and trends of: (I) overall; (II) deep; and (III) superficial SSIs following revision THA using the most recent results (2011 to 2016) from a large, nationwide database. METHODS: The National Surgical Quality Improvement Program (NSQIP) database was queried for all revision THA cases (CPT code 27134) between 2011 and 2016, yielding 8,562 cases. A steady increase in the total number of revision THA cases was observed from 2011 to 2016 (750 vs. 1,951, 260%). Cases with reported superficial and/or deep SSI were analyzed separately and then combined to evaluate overall SSI rates. The infection incidence for each year was calculated. After an overall 6-year correlation and trends analysis, univariate analysis was performed to compare the most recent year, 2016, with each of the preceding 5 years. Additionally, percent differences between 2016 and each previous year were calculated to evaluate rate changes. Pearson correlation coefficients and chi-squared tests were used to determine correlation and statistical significance which was maintained at a P value less than 0.05. RESULTS: There were 217 cases out of 8,562 (2.53% of all cases) complicated by any SSI. Overall, there was an inverse correlation between combined SSI rate and year, however, this was not statistically significant (P>0.05). The lowest incidence was in 2016 (n=41, 2.10%), while the highest incidence was in 2014 (n=45, 2.86%). The combined SSI rate in 2016 decreased by 22% when compared to 2015 (2.10% vs. 2.69%, P>0.05). A larger, 27% decrease in rate was found between 2016 and 2014 (2.10% vs. 2.86%, P>0.05). For deep SSI, there was an inverse correlation between rate and year of surgery, however, this was not statistically significant (P>0.05). The deep SSI incidence over the 5 years was 1.38% (118 out of 8,562 cases). There was a 35% decrease in deep SSI rate from 2016 to 2015 (0.92% vs. 1.43%, P>0.05). A larger, 53% decrease, was seen between 2016 and 2014 (0.92% vs. 1.04%, P<0.01). For superficial SSI, there was an inverse correlation between rate and year, however, this was not statistically significant (P>0.05). In this 6-year period, 99 cases out of 8,562 were complicated by a superficial SSI; an incidence of 1.16%. The lowest incidence occurred in 2014 (n=14, 0.89%), while 2012 had the highest incidence (n=17, 1.61%). The rate in 2016 decreased by 6% when compared to 2015 (1.18% vs. 1.07%, P>0.05). A larger, 27% decrease in rate was observed between 2016 and 2012 (1.18% vs. 1.61%, P>0.05). CONCLUSIONS: Revision total hip arthroplasties exhibited a trend towards decreasing overall SSI nationwide between 2011 and 2016. Deep SSI rates had marked improvements, specifically between 2014 and 2016. This trend indicates some benefit from pre- and post-operative infection preventative strategies, but importantly, indicates continued room for improvement. Due to the potentially devastating complications associated with infection in revision THAs, further research is required to identify revision-specific strategies to lower the rates of SSIs.

A comparison of peri-operative outcomes between elective and non-elective total hip arthroplasties.

BACKGROUND: Elective total hip arthroplasties (THAs) entail a more extensive pre-operative planning process compared to non-elective THAs and this may contribute to a disparity in outcomes. However, the differences in peri- and post-operative outcomes between elective and non-elective THAs remain unclear. Therefore, the purpose of this study was to: (I) determine nationwide trends in operative times and (II) evaluate the association between surgery type, elective or non-elective with respect to (I) operative times; (II) hospital lengths-of-stay (LOS); (III) discharge disposition; (IV) 30-day post-operative complications; (V) reoperations; and (VI) readmissions. METHODS: The NSQIP database was queried for all primary THAs (CPT code 27130) performed between 2011 and 2016. This yielded 130,261 cases, which were then stratified into elective (n=125,293) and non-elective (n=4,968) cases. One-way analysis of variance (ANOVA) were used to evaluate the associations between operative times and surgery year. Univariate analyses of surgery type with the following outcomes of interest were also performed: operative times, LOS, and discharge disposition as well as 30-day complication, reoperation, and readmission rates. A multiple linear regression model was used to evaluate the relationships of operative times and LOS with surgery types after adjusting for surgery year and patient factors [age, sex, body mass index (BMI), and American Society of Anesthesiologists (ASA) score]. A log-transformed dependent variable was used to calculate the percentage difference in mean operative times and LOS. Multivariate logistic regression models adjusted for patient factors and year of surgery were used to evaluate associations of surgery type with complication, reoperation, and readmission rates. RESULTS: Over the 6-year period, mean operative times (93 vs. 103 minutes, P<0.001) and LOS (3 vs. 6 days, P<0.001) were significantly shorter in elective cases compared to non-elective cases. The relationships between operative times or LOS and surgery type remained significant even after adjusting for age, sex, BMI, ASA, and year of surgery (P<0.001). Compared to the non-elective cohort, patients in the elective cohort were more likely to be discharged home (74% vs. 69%, P<0.001). Elective patients had lower rates of several 30-day complications including deep SSI (P<0.001), transfusions (P<0.001), sepsis (P<0.001), and readmission (P<0.005) compared to non-elective patients. These associations remained significant after accounting for potential confounders with multivariate logistic regression. CONCLUSIONS: Findings from this study showed that elective THAs, in which there is more potential for pre-operative planning, were associated with shorter operative times and LOS, as well as fewer complication and readmission rates. These results likely reflect the development of more efficient surgical techniques and improved pre- and intra-operative planning guides.