Aims. The aims of this study were to characterize the frequency of missing data in the National Surgical Quality Improvement Program (NSQIP) database and to determine how missing data can influence the results of studies dealing with elderly patients with a fracture of the hip. Patients and Methods. Patients who underwent surgery for a fracture of the hip between 2005 and 2013 were identified from the NSQIP database and the percentage of missing data was noted for demographics, comorbidities and laboratory values. These variables were tested for association with ‘any adverse event’ using multivariate regressions based on common ways of handling missing data. Results. A total of 26 066 patients were identified. The rate of missing data was up to 77.9% for many variables. Multivariate regressions comparing three methods of handling missing data found different risk factors for postoperative adverse events. Only seven of 35 identified risk factors (20%) were common to all three analyses. Conclusion. Missing data is an important issue in national database studies that researchers must consider when evaluating such investigations. Cite this article: Bone Joint J 2018;100-B:226–32

Aims

This study aimed to investigate the risk of postoperative complications in COVID-19-positive patients undergoing common orthopaedic procedures.

Aims

The aim of this study was to compare the rate of perioperative complications following aseptic revision total hip arthroplasty (THA) in patients aged ≥ 80 years with that in those aged < 80 years, and to identify risk factors for the incidence of serious adverse events in those aged ≥ 80 years using a large validated national database.

Aims

The aim of this study was to determine the impact of the severity of anaemia on postoperative complications following total hip arthroplasty (THA) and total knee arthroplasty (TKA).

Use of large databases for orthopaedic research has increased exponentially. Each database represents unique patient populations and vary in methodology of data acquisition. The purpose of this study was to evaluate differences in reported demographics, comorbidities and complications following total hip arthroplasty (THA) amongst four commonly used databases. Patients who underwent primary THA during 2010–2012 were identified within National Surgical Quality Improvement Programs (NSQIP), Nationwide Inpatient Sample (NIS), Medicare Standard Analytic Files (MED) and Humana Claims Database (HAC). NSQIP definitions for comorbidities and surgical complications were queried in NIS, MED, and HAC using coding algorithms. Age, sex, comorbidities, inpatient and 30-day postoperative complications were compared (NIS has inpatient data only). Primary THAs from each database were 22,644 (HAC), 371,715 (MED), 188,779 (NIS) and 27,818 (NSQIP). Age and gender distribution were similar between databases. There was variability in the prevalence of comorbidities and complications depending upon the database and duration of post-operative follow-up. HAC and MED had twice the prevalence of COPD, coagulopathy and diabetes than NSQIP. NSQIP had more than twice the obesity than NIS. HAC had more than twice the rates of 30-day complications at all endpoints compared to NSQIP and more than twice the DVTs, strokes and deep infection as MED at 30-days post-op. Comparison of inpatient and 30-day complications rates demonstrated more than twice the amount of infections and DVTs are captured when analysis is extended from inpatient stay to 30-days post-op. Amongst databases commonly used in orthopaedic research, there is considerable variation in complication rates following THA depending upon the database. It will be important to consider these differences when critically evaluating database research. Additionally, with the advent of bundled payments, these differences must be considered in risk adjustment models

Over 300,000 total hip arthroplasties (THA) are performed annually in the USA. Surgical Site Infections (SSI) are one of the most common complications and are associated with increased morbidity, mortality and cost. Risk factors for SSI include obesity, diabetes and smoking, but few studies have reported on the predictive value of pre-operative blood markers for SSI. The purpose of this study was to create a clinical prediction model for acute SSI (classified as either superficial, deep and overall) within 30 days of THA based on commonly ordered pre-operative lab markers and using data from the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database. All adult patients undergoing an elective unilateral THA for osteoarthritis from 2011–2016 were identified from the NSQIP database using Current Procedural Terminology (CPT) codes. Patients with active or chronic, local or systemic infection/sepsis or disseminated cancer were excluded. Multivariate logistic regression was used to determine coefficients, with manual stepwise reduction. Receiver Operating Characteristic (ROC) curves were also graphed. The SSI prediction model included the following covariates: body mass index (BMI) and sex, comorbidities such as congestive heart failure (CHF), chronic obstructive pulmonary disease (COPD), smoking, current/previous steroid use, as well as pre-operative blood markers, albumin, alkaline phosphate, blood urea nitrogen (BUN), creatinine, hematocrit, international normalized ratio (INR), platelets, prothrombin time (PT), sodium and white blood cell (WBC) levels. Since the data met logistic assumption requirements, bootstrap estimation was used to measure internal validity. The area under the ROC curve for final derivations along with McFadden's R-squared were utilized to compare prediction models. A total of 130,619 patients were included with the median age of patients at time of THA was 67 years (mean=66.6+11.6 years) with 44.8% (n=58,757) being male. A total of 1,561 (1.20%) patients had a superficial or deep SSI (overall SSI). Of all SSI, 45.1% (n=704) had a deep SSI and 55.4% (n=865) had a superficial SSI. The incidence of SSI occurring annually decreased from 1.44% in 2011 to 1.16% in 2016. Area under the ROC curve for the SSI prediction model was 0.79 and 0.78 for deep and superficial SSI, respectively and 0.71 for overall SSI. CHF had the largest effect size (Odds Ratio(OR)=2.88, 95% Confidence Interval (95%CI): 1.56 – 5.32) for overall SSI risk. Albumin (OR=0.44, 95% CI: 0.37 – 0.52, OR=0.31, 95% CI: 0.25 – 0.39, OR=0.48, 95% CI: 0.41 – 0.58) and sodium (OR=0.95, 95% CI: 0.93 – 0.97, OR=0.94, 95% CI: 0.91 – 0.97, OR=0.95, 95% CI: 0.93 – 0.98) levels were consistently significant in all clinical prediction models for superficial, deep and overall SSI, respectively. In terms of pre-operative blood markers, hypoalbuminemia and hyponatremia are both significant risk factors for superficial, deep and overall SSI. In this large NSQIP database study, we were able to create an SSI prediction model and identify risk factors for predicting acute superficial, deep and overall SSI after THA. To our knowledge, this is the first clinical model whereby pre-operative hyponatremia (in addition to hypoalbuminemia) levels have been predictive of SSI after THA. Although the model remains without external validation, it is a vital starting point for developing a risk prediction model for SSI and can help physicians mitigate risk factors for acute SSI post THA

Total knee and hip arthroplasty (TKA and THA) are two of the highest volume and resource intensive surgical procedures. Key drivers of the cost of surgical care are duration of surgery (DOS) and postoperative inpatient length of stay (LOS). The ability to predict TKA and THA DOS and LOS has substantial implications for hospital finances, scheduling and resource allocation. The goal of this study was to predict DOS and LOS for elective unilateral TKAs and THAs using machine learning models (MLMs) constructed on preoperative patient factors using a large North American database. The American College of Surgeons (ACS) National Surgical and Quality Improvement (NSQIP) database was queried for elective unilateral TKA and THA procedures from 2014-2019. The dataset was split into training, validation and testing based on year. Multiple conventional and deep MLMs such as linear, tree-based and multilayer perceptrons (MLPs) were constructed. The models with best performance on the validation set were evaluated on the testing set. Models were evaluated according to 1) mean squared error (MSE), 2) buffer accuracy (the number of times the predicted target was within a predesignated buffer of the actual target), and 3) classification accuracy (the number of times the correct class was predicted by the models). To ensure useful predictions, the results of the models were compared to a mean regressor. A total of 499,432 patients (TKA 302,490; THA 196,942) were included. The MLP models had the best MSEs and accuracy across both TKA and THA patients. During testing, the TKA MSEs for DOS and LOS were 0.893 and 0.688 while the THA MSEs for DOS and LOS were 0.895 and 0.691. The TKA DOS 30-minute buffer accuracy and ≤120 min, >120 min classification accuracy were 78.8% and 88.3%, while the TKA LOS 1-day buffer accuracy and ≤2 days, >2 days classification accuracy were 75.2% and 76.1%. The THA DOS 30-minute buffer accuracy and ≤120 min, >120 min classification accuracy were 81.6% and 91.4%, while the THA LOS 1-day buffer accuracy and ≤2 days, >2 days classification accuracy were 78.3% and 80.4%. All models across both TKA and THA patients were more accurate than the mean regressors for both DOS and LOS predictions across both buffer and classification accuracies. Conventional and deep MLMs have been effectively implemented to predict the DOS and LOS of elective unilateral TKA and THA patients based on preoperative patient factors using a large North American database with a high level of accuracy. Future work should include using operational factors to further refine these models and improve predictive accuracy. Results of this work will allow institutions to optimize their resource allocation, reduce costs and improve surgical scheduling. Acknowledgements:. The American College of Surgeons National Surgical Quality Improvement Program and the hospitals participating in the ACS NSQIP are the source of the data used herein; they have not verified and are not responsible for the statistical validity of the data analysis or the conclusions derived by the authors

Aims. While use of large national clinical databases for orthopaedic trauma research has increased dramatically, there has been little study of the differences in populations contained therein. In this study we aimed to compare populations of patients with femoral shaft fractures across three commonly used national databases, specifically with regard to age and comorbidities. Patients and Methods. Patients were identified in the Nationwide Inpatient Sample (NIS), National Surgical Quality Improvement Program (NSQIP) and National Trauma Data Bank (NTDB). . Results. The distributions of age and Charleston comorbidity index (CCI) reflected a predominantly older population with more comorbidities in NSQIP (mean age 71.5; . sd. 15.6), mean CCI 4.9; . sd. 1.9) than in the NTDB (mean age 45.2; . sd. 21.4), mean CCI = 2.1; . sd. 2.0). Bimodal distributions in the NIS population showed a more mixed population (mean age 56.9; . sd.  24.9), mean CCI 3.2; . sd. 2.3). Differences in age and CCI were all statistically significant (p <  0.001). . Conclusion. While these databases have been commonly used for orthopaedic trauma research, differences in the populations they represent are not always readily apparent. Care must be taken to understand fully these differences before performing or evaluating database research, as the outcomes they detail can only be analysed in context. Take home message: Researchers and those evaluating research should be aware that orthopaedic trauma populations contained in commonly studied national databases may differ substantially based on sampling methods and inclusion criteria. Cite this article: Bone Joint J 2016;98-B:425–32

To describe the longitudinal trends in patients with obesity and Metabolic Syndrome (MetS) undergoing TKA and the associated impact on complications and lengths of hospital stay. We identified patients who underwent primary TKA between 2006 – 2017 within the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database. We recorded patient demographics, length of stay (LOS), and 30-day major and minor complications. We labelled those with an obese Body Mass Index (BMI ≥ 30), hypertension, and diabetes as having MetS. We evaluated mean BMI, LOS, and 30-day complication rates in all patients, obese patients, and those with MetS from 2006-2017. We used multivariable regression to evaluate the trends in BMI, complications, and LOS over time in all patients and those with MetS, and the effect of BMI and MetS on complication rates and LOS, stratified by year. 270,846 patients underwent primary TKA at hospitals participating in the NSQIP database. 63.71% of patients were obese (n = 172,333), 15.21% were morbidly obese (n = 41,130), and 12.37% met criteria for MetS (n = 33,470). Mean BMI in TKA patients increased at a rate of 0.03 per year (0.02-0.05; p < 0 .0001). Despite this, the rate of adverse events in obese patients decreased: major complications by an odds ratio (OR) of 0.94 (0.93-0.96; p < 0 .0001) and minor complications by 0.94 (0.93-0.95; p < 0 .001). LOS also decreased over time at an average rate of −0.058 days per year (-0.059 to −0.057; p < 0 .0001). The proportion of patients with MetS did not increase, however similar improvements in major complications (OR 0.94 [0.91-0.97] p < 0 .0001), minor complications (OR 0.97 [0.94-1.00]; p < 0 .0330), and LOS (mean −0.055 [-0.056 to −0.054] p < 0 .0001) were found. In morbidly obese patients (BMI ≥ 40), there was a decreased proportion per year (OR 0.989 [0.98-0.994] p < 0 .0001). Factors specifically associated with major complications in obese patients included COPD (OR 1.75 [1.55-2.00] p < 0.0001) and diabetes (OR 1.10 [1.02-1.1] p = 0.017). Hypertension (OR 1.12 [1.03-1.21] p = 0.0079) was associated with minor complications. Similarly, in patients with MetS, major complications were associated with COPD (OR 1.72 [1.35-2.18] p < 0.0001). Neuraxial anesthesia was associated with a lower risk for major complications in the obese cohort (OR 0.87 [0.81-0.92] p < 0.0001). BMI ≥ 40 was associated with a greater risk for minor complications (OR 1.37 [1.26-1.50] p < 0.0001), major complications (1.11 [1.02-1.21] p = 0.015), and increased LOS (+0.08 days [0.07-0.09] p < 0.0001). Mean BMI in patients undergoing primary TKA increased from 2006 - 2017. MetS comorbidities such as diabetes and hypertension elevated the risk for complications in obese patients. COPD contributed to higher rates of major complications. The obesity-specific risk reduction with spinal anesthesia suggests an improved post-anesthetic clinical course in obese patients with pre-existing pulmonary pathology. Encouragingly, the overall rates of complications and LOS in patients with obesity and MetS exhibited a longitudinal decline. This finding may be related to the decreased proportion of patients with BMI ≥ 40 treated over the same period, possibly the result of quality improvement initiatives aimed at delaying high-risk surgery in morbidly obese patients until healthy weight loss is achieved. These findings may also reflect increased awareness and improved management of these patients and their elevated risk profiles

This study was designed to compare atypical hip fractures with a matched cohort of standard hip fractures to evaluate the difference in outcomes. Patients from the American College of Surgeons National Surgical Quality Improvement Program's (NSQIP) targeted hip fracture data file (containing a more comprehensive set of variables collected on 9,390 specially targeted hip fracture patients, including the differentiation of atypical from standard hip fractures) were merged with the standard 2016 NSQIP data file. Atypical hip fracture patients aged 18 years and older in 2016 were identified via the targeted hip fracture data file and matched to two standard hip fracture controls by age, sex, and fracture location. Patient demographics, length of hospital stay, 30-day mortality, major and minor complications, and other hip-specific variables were identified from the database. Binary outcomes were compared using the McNemar's test for paired groups, and continuous outcomes were compared using a paired t-test. Ninety-five atypical hip fractures were identified, and compared to 190 age, sex, and fracture location matched standard hip fracture controls. There was no statistical difference in body mass index (BMI), race, ASA score, smoking status, timing of fixation, or functional status between the two groups (P>0.05). Thirty-day mortality was significantly higher in the atypical hip fracture group (atypical 7.36%, standard 2.11% p. This is the first study, to our knowledge, that demonstrates an increase in the rate of mortality in atypical hip fractures. Comparing atypical hip fractures with a matched cohort of standard hip fractures revealed a significantly greater 30-day mortality rate with an odds ratio of 3.62 in atypical hip fractures (95% CI 1.03–12.68). Prospective, clinical studies are recommended to further investigate these findings

Delayed management of high energy femoral shaft fractures is associated with increased complication rates. It has been suggested that there is less urgency to stabilize lower energy femoral shaft fractures. The purpose of this study was to evaluate the effect of surgical delay on 30-day complications following fixation of lower energy femoral shaft fractures. Patients ≥ 18 years who underwent either plate or nail fixation of low energy (falls from standing or up to three steps' height) femoral shaft fractures from 2005 – 2016 were identified from the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) via procedural codes. Patients with pathologic fractures, fractures of the distal femur or femoral neck were excluded. Patients were categorized into early (< 2 4 hours) or delayed surgery (2–30 days) groups. Bivariate analyses were used to compare demographics and unadjusted rates of complications between groups. A multivariable logistic regression was used to compare the rate of major and minor complications between groups, while adjusting for relevant covariables. Head injury patients and polytrauma patients are not included in the NSQIP database. Of 2,716 lower energy femoral shaft fracture patients identified, 2,412 (89%) were treated within 1 day of hospital admission, while 304 (11.2%) were treated between 2 and 30 days post hospital admission. Patient age, American Society of Anesthesiologists (ASA) classification score, presence of diabetes, functional status, smoking status, and surgery type (nail vs. plate) were significantly different between groups (p After adjusting for all relevant covariables, delayed surgery significantly increased the odds of 30-day minor complications (p=0.02, OR = 1.48 95%CI 1.01–2.16), and 30-day mortality (p < 0 .001), OR = 1.31 (95%CI 1.03–2.14). The delay of surgical fixation of femoral shaft fractures appears to significantly increase patients' risk of minor adverse events as well as increase mortality. With only 89% of patients being treated in the 24 hour timeframe that constitutes best practice for treatment of femoral shaft fractures, there remains room for improvement. These results suggest that early treatment of all femoral shaft fractures, even those with a lower energy mechanism of injury, leads to improved outcomes

The brief answer is no….I do not believe that outpatient total joint arthroplasty is the emergent standard of care. However, for some patients and some surgeons I do believe that outpatient total joint arthroplasty can be performed safely and with greater comfort and convenience for the patient. Further, for the surgeon, it can provide greater control over the care environment if performed at an ambulatory surgery center. Patient selection is paramount in my opinion for safely performing outpatient total joint arthroplasty. While some have attempted to define specific criteria, our own criteria include patients with simple orthopaedic problems who are healthy, trustworthy and have a good support system of family or friends to assist them. As surgeons we must also be self-aware as the margin for error, particularly at a freestanding ambulatory surgery center, is narrow. Operative times should be reliably brief and blood loss should be minimal to allow for a safe discharge on the same day. Further the incidence of intraoperative complications such as fractures at the time of total hip arthroplasty or ligament injuries during total knee arthroplasty should be low. The surgeon should also be prepared with the equipment to address these common issues, if they do occur. In our review of the NSQIP data set we matched 1,236 outpatient TJA 1:1 with inpatients based on propensity scores. The risk of 30-day readmissions and complications was no different between groups, although inpatients had a higher rate of VTE and outpatients had a higher risk of re-operation. Risk factors for adverse events included patient age > 85 years old, diabetes and BMI > 35. Likewise in a review of results from my own practice, we have seen no difference in the risk of complications. As health care providers we must keep the safety of our patients paramount at all times. Further, we must be fiscally responsible to avoid costly complications, reoperations and readmissions. With conservative patient selection and careful surgical technique I believe that outpatient TJA offers an attractive alternative that is safe, cost effective and associated with high satisfaction for both patients and surgeons

Background. Standard preoperative protocols in total joint arthroplasty utilize the International Normalized Ratio (INR) to determine patient coagulation profiles. However, the relevance of preoperative INR values in joint arthroplasty remains controversial. Acceptable INR cutoff values for joint replacement are inconsistent, and are often based on studies of primary arthroplasty, or even non-orthopedic procedures. This analysis examined the relationship between preoperative INR values and post-operative outcomes in revision total hip arthroplasty (rTHA). Optimal cutoff INR values correlated with specific outcomes were subsequently determined. Methods. The American College of Surgeons National Surgical Quality Improvement Program (NSQIP) was retrospectively queried for revision total hip arthroplasty procedures performed between 2006 and 2017. Patients with a preoperative INR collected no later than 1 day prior to surgery were further stratified for analysis. INR values which correlated with specific outcomes were determined using receiver operating characteristics (ROC) curves for each outcome of interest. The optimal cutoff INR value for each outcome was then obtained using univariate and multivariate models which determined INR values that maximized both sensitivity and specificity. Results. There were a total of 11,393 patients who underwent a revision total hip arthroplasty from 2006–2017 recorded in NSQIP. Of the 2,012 patients who met inclusion and exclusion criteria, 858 had an INR < 1.0, 931 had an INR > 1.0 to 1.25, 175 had an INR > 1.25 to 1.5, and 48 patients had an INR > 1.5. Patients with progressively higher INR values had a significantly different risk of mortality within 30 days (p=0.005), bleeding requiring transfusion (p< 0.001), sepsis (p=0.002), stroke (p<0.001), failure to wean from ventilator within 48 hours (p=0.001), readmission (p=0.01), and hospital length of stay (p< 0.001). Similar results were obtained when utilizing optimal INR cutoff values. When correcting for other factors, the following poor outcomes were significantly associated with the respective INR cutoff values (Estimate, 95% CI, p value): LOS (1.67, 1.34–2.08, p <0.001), bleeding requiring transfusion (1.65, 1.30–2.09, p<0.001), sepsis (2.15, 1.11–4.17, p 0.02), and any infection (1.82, 1.01–3.29, p 0.04). Conclusions. INR values >1.65, >1.67, >1.82, and >2.15 were correlated with increased transfusion requirements, LOS, any infection, and sepsis respectively. Therefore, even subtherapeutic elevations in INR may predict poor outcomes following revision total joint replacement. Surgeons and perioperative medical specialists should consider more stringent INR goals when optimizing patients prior to revision arthroplasty. Level of Evidence. Prognostic Level IV. For any figures or tables, please contact authors directly

Total knee arthroplasty (TKA) is the most commonly performed elective orthopaedic procedure. With an increasingly aging population, the number of TKAs performed is expected to be ∼2,900 per 100,000 by 2050. Surgical Site Infections (SSI) after TKA can have significant morbidity and mortality. The purpose of this study was to construct a risk prediction model for acute SSI (classified as either superficial, deep and overall) within 30 days of a TKA based on commonly ordered pre-operative blood markers and using audited administrative data from the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database. All adult patients undergoing an elective unilateral TKA for osteoarthritis from 2011–2016 were identified from the NSQIP database using Current Procedural Terminology (CPT) codes. Patients with active or chronic, local or systemic infection/sepsis or disseminated cancer were excluded. Multivariate logistic regression was conducted to estimate coefficients, with manual stepwise reduction to construct models. Bootstrap estimation was administered to measure internal validity. The SSI prediction model included the following co-variates: body mass index (BMI) and sex, comorbidities such as congestive heart failure (CHF), chronic obstructive pulmonary disease (COPD), smoking, current/previous steroid use, as well as pre-operative blood markers, albumin, alkaline phosphatase, blood urea nitrogen (BUN), creatinine, hematocrit, international normalized ratio (INR), platelets, prothrombin time (PT), sodium and white blood cell (WBC) levels. To compare clinical models, areas under the receiver operating characteristic (ROC) curves and McFadden's R-squared values were reported. The total number of patients undergoing TKA were 210,524 with a median age of 67 years (mean age of 66.6 + 9.6 years) and the majority being females (61.9%, N=130,314). A total of 1,674 patients (0.8%) had a SSI within 30 days of the index TKA, of which N=546 patients (33.2%) had a deep SSI and N=1,128 patients (67.4%) had a superficial SSI. The annual incidence rate of overall SSI decreased from 1.60% in 2011 to 0.68% in 2016. The final risk prediction model for SSI contained, smoking (OR=1.69, 95% CI: 1.31 – 2.18), previous/current steroid use (OR=1.66, 95% CI: 1.23 – 2.23), as well as the pre-operative lab markers, albumin (OR=0.46, 95% CI: 0.37 – 0.56), blood urea nitrogen (BUN, OR=1.01, 95% CI: 1 – 1.02), international normalized ratio (INR, OR=1.22, 95% CI:1.05 – 1.41), and sodium levels (OR=0.94, 95% CI: 0.91 – 0.98;). Area under the ROC curve for the final model of overall SSI was 0.64. Models for deep and superficial SSI had ROC areas of 0.68 and 0.63, respectively. Albumin (OR=0.46, 95% CI: 0.37 – 0.56, OR=0.33, 95% CI: 0.27 – 0.40, OR=0.75, 95% CI: 0.59 – 0.95) and sodium levels (OR=0.94, 95% CI: 0.91 – 0.98, OR=0.96, 95% CI: 0.93 – 0.99, OR=0.97, 95% CI: 0.96 – 0.99) levels were consistently significant in all prediction models for superficial, deep and overall SSI, respectively. Overall, hypoalbuminemia and hyponatremia are both significant risk factors for superficial, deep and overall SSI. To our knowledge, this is the first prediction model for acute SSI post TKA whereby hyponatremia (and hypoalbuminemia) are predictive of SSI. This prediction model can help fill an important gap for predicting risk factors for SSI after TKA and can help physicians better optimize patients prior to TKA

Among the most critical factors to reducing the risk of infection include the use of pre-incisional antibiotics, appropriate skin preparation with clippers (as opposed to a razor for hair removal) and the use of an alcohol-based skin preparation. Host factors are also likewise critically important including obesity, diabetes, inflammatory arthritis, renal insufficiency, skin disorders and patients who are otherwise immune-compromised. If modifiable risk factors are identified, it would seem reasonable to delay elective surgery until these can be optimised. One other factor to consider is the nutritional status of the patient. In a study of 501 consecutive revisions, we found that serological markers suggestive of malnutrition (albumin, transferrin or total lymphocyte count) were extremely common. Specifically, 53% of patients who presented for treatment of a chronic infection had at least one marker for malnutrition, compared to 33% in the group of patients undergoing revision for an aseptic reason. Malnutrition was found to be an independent risk factor for septic failure (p < 0.001 and OR 2.1). Interestingly, malnutrition was most common among patients of normal weight but was also common among obese patients (so-called “paradoxical” malnutrition). What was more disturbing, however, was that of those patients undergoing an aseptic revision, serum markers of malnutrition were associated with a 6× risk of acute post-operative infection complicating the patient's aseptic revision. We have confirmed this association using the NSQIP database where hypoalbuminemia was associated with a higher risk of infection, pneumonia and readmission. At our center, we also have studied the use of dilute betadine at the end of the case, prior to wound closure, in an attempt to decrease the load of bacteria in the wound. In a retrospective review the prevalence of acute post-operative infection was reduced from just under 1% (18/1862) to 0.15% (1 of 688; p = 0.04). It is critical that the betadine utilised be STERILE and the dilution we use is 0.35% made by diluting 17.5cc of 10% povidone-iodine paint in 500cc of normal saline

An outpatient total hip arthroplasty (THA) will be defined as a THA performed at an ambulatory care facility where the patient is discharged the same day as the procedure. Such procedures are being done in the United States and the hypothesis is that a “same day” THA will lead to reduced costs and improved outcomes. However, there are no appropriately powered randomised controlled trials evaluating outcomes in this group of patients to support this hypothesis. It appears that a “same day” THA is here to stay. Therefore, the selection criteria for patients that undergo the procedure needs to be carefully defined. The safety of this regimen needs to be confirmed. In an evaluation of the NSQIP database, Otero et al. compared outcomes in patients discharged on POD 0 and POD 1 and noted that THA patients in the POD 0 group had increased rates of complications. Risk factors for complications included age >70, smoking, COPD, CAD and hematocrit less than 36. In addition, the patients discharged on POD 0 had higher rates of diabetes, steroid use and lower hematocrit. Clearly, the selection criteria for this procedure needs to be defined. In two separate studies, Goyal et al. and Dorr et al. noted that approximately 25% of patients were unable to leave the hospital on POD 0 usually because of nausea and/or hypertension. Issues to consider before developing a same day discharge program include: 1) Is the patient healthy enough to go home the same day as the surgery?; 2) Does the patient live close enough to the hospital to be discharged the same day?; 3) Can the family provide the appropriate care for the patient at home?; 4) Is it really better for the patient or just better for the surgeon?. If a surgeon embarks on a same day discharge program, rigorous selection criteria must be instituted and followed. In addition, the patient must have free choice with respect to a same day discharge versus a 24-hour stay

Aims

In the last decade, perioperative advancements have expanded the use of outpatient primary total knee arthroplasty (TKA). Despite this, there remains limited data on expedited discharge after revision TKA. This study compared 30-day readmissions and reoperations in patients undergoing revision TKA with a hospital stay greater or less than 24 hours. The authors hypothesized that expedited discharge in select patients would not be associated with increased 30-day readmissions and reoperations.

Utilising the (ACS-NSQIP) database, we aimed to evaluate the impact of resident level of training on surgical outcome following (TKA) and to compare the US and Canadian health care training system in regards to 30 days postoperative complications and readmission rates. Using the (CPT) codes we selected from the 2011 and 2012 NSQIP database elective primary TKA with the resident surgeon involved. Of these, all cases with a primary diagnosis code of infection, fracture, mechanical complication, or malignancy and all cases with incomplete or incongruous demographic information were excluded. We also eliminated all the cases with the Attending not present. A total of 2513 cases were included in the study. The cases were stratified into three groups according to the postgraduate level of training {PGY 1 to 3 (junior resident), PGY 4 to 5 (senior resident), and fellow}. Univariate analysis of all patient demographics, comorbidities, intra and postoperative variables, length of surgery, hospital stay and 30 days readmission rates were conducted in order to identify differences between the groups. A standard student's t test was used for continuous variables while the ChiSquared was used for categorical variables. Multivariable logistic regression models were created to assess the independent effect of the resident level of training on the 30 days major complication and re-admission rates while controlling for all other variables. We identified, 854 (34%) TKAs with junior residents, 1013 (40%) TKAs with senior residents and 646 (26%) TKAs with fellows' participation. Junior residents had a significant (p<0.0001) longer operative time (107±36 minutes) compared with senior residents and fellows. Length of hospital stay was longer in the fellow group probably because of their involvement in more complicated cases. Additionally, an increased number of blood transfusion was observed for the cases performed with involvement of senior residents when compared with the other two groups. However, no significant difference in complications was observed across training levels. When comparing US (2074 TKAs) versus Canada (423 TKAs) cases, we found that fellow contribution to TKA surgeries is higher in Canada. The occurrence of pulmonary embolism and pneumonia was three times higher in Canada cases, while blood transfusion was more frequent in US. Increased operative time, ASA class, age, diabetes, percutaneous cardiac intervention, and steroid use were all independent risk factors for complications following primary TKA. However, no significant difference was observed between the two groups with regards to major complications suggesting no difference between Canadian and American training system in regards to post operative complication. Our results support previous study study indicating that involvement of residents did not affect the surgical outcome within 30 days when compared to cases with no resident involvement. Our study suggests that resident level does not independently increase the risk of short term complications and support continuing involvement of junior trainees in TKA

Aims

To identify variables independently associated with same-day discharge (SDD) of patients following revision total knee arthroplasty (rTKA) and to develop machine learning algorithms to predict suitable candidates for outpatient rTKA.