Wound Complications Are Affected by Different Skin Closure Methods in Primary Hip and Knee Arthroplasty.

BACKGROUND: There is a lack of consensus on optimal skin closure and dressing strategies to reduce early wound complication rates after primary total hip arthroplasty (THA) and total knee arthroplasty (TKA). METHODS: All 13,271 patients at low risk for wound complications undergoing primary, unilateral THA (7,816), and TKA (5,455) for idiopathic osteoarthritis at our institution between August 2016 and July 2021 were identified. Skin closure, dressing type, and postoperative events related to wound complications were recorded during the first 30 postoperative days. RESULTS: The need for unscheduled office visits to address wound complications was more frequent after TKA than THA (2.74 versus 1.78%, P < .001), and after direct anterior versus posterior approach THA (2.94 versus 1.39%, P < .001). Patients who developed a wound complication, had a mean of 2.9 additional office visits. Compared to the use of topical adhesives, skin closure with staples had the highest risk of wound complications (odds ratio 1.8 [1.07-3.11], P = .028). Topical adhesives with polyester mesh had higher rates of allergic contact dermatitis than topical adhesives without mesh (1.4 versus 0.5%, P < .0001). CONCLUSION: Wound complications after primary THA and TKA were often self-limited but increased burden on the patient, surgeon, and care team. These data, which suggest different rates of certain complications with different skin closure strategies, can inform a surgeon on optimal closure methods in their practice. Adoption of the skin closure technique with the lowest risk of complications in our hospital would conservatively result in a reduction of 95 unscheduled office visits and save a projected $585,678 annually.

Variability of pre-operative functional pelvic tilt in total hip arthroplasty patients.

PURPOSE: Pelvic tilt (PT) is important to consider when planning total hip arthroplasty (THA) due to its dynamic impact on acetabular orientation. The degree of sagittal pelvic rotation varies during functional activities and can be difficult to measure without proper imaging. The purpose of this study was to evaluate PT variation in the supine, standing, and seated positions. METHODS: A multi-centre cross-sectional study was performed that included 358 THA patients who had preo-perative PT measured from supine CT scan and standing and upright seated lateral radiographs. Supine, standing, and seated PT and associated changes between functional positions were evaluated. Anterior PT was assigned a positive value. RESULTS: In the supine position, mean PT was 4° (range, -35° to 20°), where 23% had posterior PT and 69% anterior PT. In the standing position, mean PT was 1° (range, -23° to 29°), where 40% had posterior PT and 54% anterior PT. In the seated position, mean PT was -18° (range, -43° to 47°), where 95% had posterior PT and 4% anterior PT. From standing to seated, the pelvis rotated posteriorly in 97% of cases (maximum 60°) with 16% of cases considered stiff (change ≤ 10°) and 18% of cases considered hypermobile (change ≥ 30°). CONCLUSION: Patients undergoing THA have marked PT variation in the supine, standing, and seated positions. There was wide variability in PT change from standing to seated, with 16% of patients considered stiff and 18% considered hypermobile. Functional imaging should be performed on patients prior to THA to allow for more accurate planning.

Patients Who Undergo Early Aseptic Revision TKA Within 90 Days of Surgery Have a High Risk of Re-revision and Infection at 2 Years: A Large-database Study.

BACKGROUND: Early aseptic revision within 90 days after primary TKA is a devastating complication. The causes, complications, and rerevision risks of aseptic revision TKA performed during this period are poorly described. QUESTIONS/PURPOSES: (1) What is the likelihood of re-revision within 2 years after early aseptic TKA revision within 90 days compared with that of a control group of patients undergoing primary TKA? (2) What are the indications for early aseptic TKA revision within 90 days? (3) What are the differences in revision risk between different indications for early aseptic revision TKA? METHODS: Patients who underwent unilateral aseptic revision TKA within 90 days of the index procedure were identified in a national insurance claims database (PearlDiver Technologies) using administrative codes. The exclusion criteria comprised revision for infection, history of bilateral TKA, and age younger than 18 years. The PearlDiver database was selected for its large and geographically diverse patient base and the availability of outpatient follow-up data that are unavailable in other databases focused on inpatient care. A total of 481 patients met criteria for early aseptic revision TKA, with 14% (67) loss to follow-up at 2 years. This final cohort of 414 patients was compared with a control group of patients who underwent primary TKA without revision within 90 days. For the control group, 137,661 patients underwent primary TKA without early revision, with 13% (18,138) loss to follow-up at 2 years. Among these patients, 414 controls were matched using a one-to-one propensity score method; no differences in age, gender, and Charlson comorbidity index score were observed between the groups. Indications for initial revision and 2-year re-revision were recorded. The Kaplan-Meier method was used to assess survival between the early revision and control groups. RESULTS: Two-year survivorship free from additional revision surgery was lower in the early aseptic revision cohort compared with the control (78% [95% confidence interval 77% to 79%] versus 98% [95% CI 96% to 99%]; p < 0.001). Among early revisions, 10% (43 of 414) of the patients underwent re-revision for periprosthetic infection with an antibiotic spacer within 2 years. The reasons for early aseptic revision TKA were instability/dislocation (37% [153 of 414]), periprosthetic fracture (23% [96 of 414]), aseptic loosening (23% [95 of 414]), pain (11% [45 of 414]), and arthrofibrosis (6% [25 of 414]). Early revision for pain was associated with higher odds of re-revision than early revisions performed for other all other reasons (44% [20 of 45] versus 29% [100 of 344]; odds ratio 2.0 [95% CI 1.0 to 3.7]; p = 0.04). CONCLUSION: Acute early aseptic revision TKA carries a high risk of re-revision at 2 years and a high risk of subsequent periprosthetic joint infection. Patients who undergo an early revision should be carefully counseled regarding the very high risk of repeat revision and discouraged from having early revision unless the indications are absolutely clear and compelling. Early aseptic revision for pain alone carries an unacceptably high risk of repeat revision and should not be performed. Adjunctive measures for infection prophylaxis should be strongly considered. Specific interventions to reduce surgical complications in this subset of patients have not been adequately studied; additional investigation of strategies to minimize the risk of reoperation or infection is warranted. LEVEL OF EVIDENCE: Level III, therapeutic study.

Etiology and Complications of Early Aseptic Revision Total Hip Arthroplasty Within 90 Days.

BACKGROUND: The etiology, complications, and rerevision risks of early aseptic revision total hip arthroplasty (THA) within 90 days are insufficiently documented. METHODS: A national insurance claims database (PearlDiver Technologies, Fort Wayne, IN) was queried for patients who underwent unilateral aseptic revision THA within 90 days of the index procedure using administrative codes. Patients who underwent revision for infection, without minimum 2-year follow-up, and younger than 18 years were excluded. This cohort was matched based on gender, age, and Charlson Comorbidity Index to a control group of patients who underwent primary THA without revision within 90 days. Two-year rerevision and 90-day complication rates were recorded. Chi-square and Fisher exact tests were used as appropriate for statistical comparison. RESULTS: Four hundred two patients met the inclusion criteria for early aseptic revision within 90 days of the index procedure and were matched to the control group. The overall 2-year rerevision rate was higher in the early revision group compared with control group (14.9% vs 2.5%, P < .001). Complications within 90 days occurred more frequently in the early revision group, including blood transfusion (10.2% vs 3.2%, P < .001), deep vein thrombosis (9.0% vs 3.2%, P = .001), and pulmonary embolism (2.74% vs 0.75%, P = .031). The most common reasons for early aseptic revision were dislocation (41.5%), fracture (38.1%), and loosening (17.4%). CONCLUSION: Early aseptic revision THA is associated with significantly higher 90-day complication rates and 2-year rerevision rates compared with a control group of primary THA without revision. The most common reasons for acute early revision were dislocation, fracture, and mechanical loosening. LEVEL OF EVIDENCE: Level III.

What Are the Reasons and Risk Factors for 30-Day Readmission After Outpatient Total Hip Arthroplasty?

BACKGROUND: A higher volume of primary total hip arthroplasty (THA) is starting to be performed as an outpatient procedure. However, data on appropriate patient selection for this surgical protocol is scarce. METHODS: Patients who underwent primary THA were identified in the 2012-2018 National Surgical Quality Improvement Program database. Outpatient procedure was defined as having a hospital length of stay of 0 days. The primary outcome was a readmission within the 30-day postoperative period. Risk factors for and effect of overnight hospital stay on 30-day readmission after outpatient THA were identified through multivariable models. Reasons for and timing of readmission were also identified. RESULTS: A total of 5245 outpatient THA patients and 44,171 patients who stayed 1 night were identified. The incidence of 30-day readmission after outpatient THA was 1.60% (95% confidence interval [CI] 1.26-1.94). Risk factors for 30-day readmission after outpatient THA include the following: older age relative to 18-60 years old (most notably 71-75 years old, relative risk [RR] = 2.3, 95% CI = 1.15-4.62; 76-80 years old, RR = 6.6, 95% CI = 3.55-12.43; and >80 years old, RR = 5.6, 95% CI = 2.43-12.89, P < .001) and bleeding disorders (RR = 4.5, 95% CI = 1.45-14.31, P = .010). For patients who had some of these risk factors, their risk of medically related 30-day readmission was reduced if they had stayed 1 night at the hospital (P < .05). The majority of readmissions were surgically related (62%), including wound complications (27%) and periprosthetic fractures (25%). CONCLUSION: The rate of 30-day readmission after outpatient THA was low. Patients who are at high risk for 30-day readmission after outpatient THA include those with older age and bleeding disorders. Some of these patients may benefit from an inpatient hospital stay.

Perioperative Outcomes of Hemiarthroplasty Versus Total Hip Arthroplasty for Geriatric Hip Fracture: The Importance of Studying Matched Populations.

BACKGROUND: Geriatric femoral neck fracture is a common injury for which hemiarthroplasty (HA) or total hip arthroplasty (THA) may be considered in select patients. As prior database studies comparing these have not used propensity matching, which is a robust statistical method of controlling for potentially confounding variables, unmatched and matched methodologies are contrasted in the present study. METHODS: Patients aged ≥70 years who underwent HA or THA for hip fractures were identified from the 2012-2015 National Surgical Quality Improvement database. Propensity score 1:1 matching was performed. Differences in rates of 30-day postoperative adverse outcomes were compared using multivariate logistic regression for unmatched and matched cohorts. RESULTS: In total, 15,558 patients (14,403 HA and 1155 THA) were evaluated. Although multivariate outcomes for the unmatched populations were different for blood transfusion, mortality, minor adverse events, major adverse events, and reoperation, multivariate outcomes for matched populations only differed for blood transfusion (odds ratio 0.6 for HA vs THA, P < .001). Of note, although readmissions were similar for the two groups, patients undergoing THA had a 5.4% greater rate of perioperative readmission due to dislocation. CONCLUSION: Geriatric patients undergoing HA and THA for hip fracture were compared with and without propensity matching. Once matching was performed, the only differences in outcomes between the two groups were a lower transfusion rate among the HA group and a greater readmission rate due to dislocation among the THA group. This suggests that either procedure can be safely considered if found to be advantageous from a longer-term outcome perspective. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Preoperative laboratory testing for total hip arthroplasty: Unnecessary tests or a helpful prognosticator.

BACKGROUND: The last decade has seen increasing initiatives to improve health care delivery while decreasing financial expenditures, as particularly exemplified by the implementation of bundled payments for lower extremity arthroplasty, which hold the providers responsible for the both the quality and cost of these procedures. In this context, the utility of routine preoperative laboratory testing is unknown. The present study characterizes the associations, if any, between preoperative sodium, blood urea nitrogen (BUN), and creatinine values and the occurrence of general health adverse outcomes following total hip arthroplasty (THA). METHODS: Patients undergoing primary THA were identified in the 2011-2015 National Surgical Quality Improvement Program. Cases with traumatic, oncologic, or infectious indications were excluded. Preoperative levels of sodium, BUN, and creatinine were tested for associations with perioperative adverse events and adverse hospital metrics using multivariate regressions that adjusted for patient baseline characteristics. RESULTS: A total of 92,093 patients were included, of which 5.25% had an abnormal preoperative sodium level, 24.20% had an abnormal preoperative BUN level, and 11.95% had an abnormal preoperative creatinine level. Abnormal preoperative sodium levels (odds ratios: 1.23-1.50, p < 0.007) and creatinine levels (odds ratios: 1.27-1.55, p < 0.007) were associated with the occurrence of all studied adverse outcomes and abnormal preoperative BUN levels (odds ratios: 1.15-1.52, p < 0.007) were associated with the occurrence of all adverse outcomes except for hospital readmission. CONCLUSIONS: Abnormal preoperative laboratory testing is significantly associated with adverse outcomes following THA, supporting the added value of laboratory evaluation of patients before elective arthroplasty procedures. STUDY DESIGN: Clinical, Level III.

What Associations Exist Between Comorbidity Indices and Postoperative Adverse Events After Total Shoulder Arthroplasty?

BACKGROUND: Comorbidity indices like the modified Charlson Comorbidity Index (mCCI) and the modified Frailty Index (mFI) are commonly reported in large database outcomes research. It is unclear if they provide greater association and discriminative ability for postoperative adverse events after total shoulder arthroplasty (TSA) than simple variables. QUESTIONS/PURPOSES: Using a large research database to examine postoperative adverse events after anatomic and reverse TSA, we asked: (1) Which demographic/anthropometric variable among age, sex, and body mass index (BMI) has the best discriminative ability as measured by receiver operating characteristics (ROC)? (2) Which comorbidity index, among the American Society of Anesthesiologists (ASA) classification, the mCCI, or the mFI, has the best ROC? (3) Does a combination of a demographic/anthropometric variable and a comorbidity index provide better ROC than either variable alone? METHODS: Patients who underwent TSA from 2005 to 2015 were identified from the National Surgical Quality Improvement Program (NSQIP). This multicenter database with representative samples from more than 600 hospitals in the United States was chosen for its prospectively collected data and documented superiority over administrative databases. Of an initial 10,597 cases identified, 70 were excluded due to missing age, sex, height, weight, or being younger than 18 years of age, leaving a total of 10,527 patients in the study. Demographics, medical comorbidities, and ASA scores were collected, while BMI, mCCI and mFI were calculated for each patient. Though all required data variables were found in the NSQIP, the completeness of data elements was not determined in this study, and missing data were treated as being the null condition. Thirty-day outcomes included postoperative severe adverse events, any adverse events, extended length of stay (LOS, defined as > 3 days), and discharge to a higher level of care. ROC analysis was performed for each variable and outcome, by plotting its sensitivity against one minus the specificity. The area under the curve (AUC) was used as a measure of model discriminative ability, ranging from 0 to 1, where 1 represents a perfectly accurate test, and 0.5 indicates a test that is no better than chance. RESULTS: Among demographic/anthropometric variables, age had a higher AUC (0.587-0.727) than sex (0.520-0.628) and BMI (0.492-0.546) for all study outcomes (all p < 0.050), while ASA (0.580-0.630) and mFI (0.568-0.622) had higher AUCs than mCCI (0.532-0.570) among comorbidity indices (all p < 0.050). A combination of age and ASA had higher AUCs (0.608-0.752) than age or ASA alone for any adverse event, extended LOS, and discharge to higher level of care (all p < 0.05). Notably, for nearly all variables and outcomes, the AUCs showed fair or moderate discriminative ability at best. CONCLUSION: Despite the use of existing comorbidity indices adapted to large databases such as the NSQIP, they provide no greater association with adverse events after TSA than simple variables such as age and ASA status, which have only fair associations themselves. Based on database-specific coding patterns, the development of database- or NSQIP-specific indices may improve their ability to provide preoperative risk stratification. LEVEL OF EVIDENCE: Level III, diagnostic study.

Surgical Treatment of Septic Shoulders: A Comparison Between Arthrotomy and Arthroscopy.

PURPOSE: To compare the efficacy, as measured through the rate of reoperation, and rates of other 30-day perioperative complications between arthrotomy and arthroscopy for the treatment of septic native shoulders in a national patient population. METHODS: Patients who were diagnosed with septic arthritis in a native shoulder and underwent irrigation and debridement through arthrotomy or arthroscopy were identified in the 2005-2016 National Surgical Quality Improvement Program database. Patient preoperative characteristics were characterized. Rate of reoperation, a proxy used to measure treatment efficacy, and other perioperative complications were compared between the 2 procedures. RESULTS: In total, 100 patients undergoing shoulder arthrotomy and 155 patients undergoing shoulder arthroscopy for septic shoulder were identified. On univariate analysis, there were no statistically significant differences in patient preoperative characteristics, operative time (60 vs. 48 minutes, P = .290), length of stay (7.5 vs. 6.6 days, P = .267), or time to reoperation (8.9 vs. 7.2 days, P = .594) between the 2 surgical groups. On multivariate analysis controlling for patient characteristics, there were no statistically significant differences in risk of reoperation (relative risk [RR] = 1.914, 99% confidence interval [CI] = 0.730-5.016, P = .083), any adverse events (RR = 1.254, 99% CI = 0.860-1.831, P = .122), minor adverse events (RR = 1.304, 99% CI = 0.558-3.047, P = .421), serious adverse events (RR = 1.306, 99% CI = 0.842-2.025, P = .118), or readmission (RR = 0.999, 99% CI = 0.441-2.261, P = .998) comparing arthrotomy with arthroscopy. CONCLUSIONS: By demonstrating similar rates of reoperation, other postoperative complications, and 30-day readmissions, the current study suggests that arthrotomy and arthroscopic surgery have similar efficacy in treating septic shoulders. However, owing to the small sample size, there is still the possibility of a type II error. LEVEL OF EVIDENCE: Level III, therapeutic retrospective comparative study.

Unlike Native Hip Fractures, Delay to Periprosthetic Hip Fracture Stabilization Does Not Significantly Affect Most Short-Term Perioperative Outcomes.

BACKGROUND: The incidence of periprosthetic hip fractures is increasing due to higher numbers of total hip arthroplasties being performed. Unlike native hip fractures, the effect of time to surgery of periprosthetic hip fractures is not well established. This study evaluates the effect of time to surgery on perioperative complications for patients with periprosthetic hip fractures. METHODS: Patients who underwent surgery for periprosthetic hip fracture were identified in the 2005-2016 National Surgical Quality Improvement Program database and stratified into 2 groups: <2 and ≥2 days from hospital admission to surgery. Multivariate regressions were used to compare risk for perioperative complications between the 2 groups. Independent risk factors for postoperative serious adverse events were characterized. RESULTS: In total, 409 (<2 days from admission to surgery) and 272 (≥2 days from admission to surgery) patients were identified. Multivariate analysis revealed only higher risk of extended postoperative stay for patients who had delays of ≥2 days to surgery compared to those who had <2 days from admission to surgery. Independent risk factors for serious adverse events included increasing age, dependent preoperative functional status, and preoperative congestive heart failure, but not time to surgery. CONCLUSION: Unlike for native hip fractures, time to surgery for periprosthetic hip fractures does not appear to affect most 30-day perioperative complications. However, it is worth noting that this study was unable to control for all potential confounders and therefore the results may not be generalizable to all types of periprosthetic hip fractures.

What Is the Adverse Event Profile After Prophylactic Treatment of Femoral Shaft or Distal Femur Metastases?

BACKGROUND: Prophylactic surgical treatment of the femur is commonly offered to patients with metastatic disease who have a high risk of impending pathologic fracture. Prophylactic fixation is associated with improved functional outcomes in appropriate patients selected based on established criteria, but the perioperative complication profile has received little attention. Given the substantial comorbidity in this population, it is important to characterize surgical risks for surgeons and patients to improve treatment decisions. QUESTIONS/PURPOSES: (1) What is the incidence of postoperative adverse events after prophylactic surgical stabilization of metastatic lesions of the femoral shaft or distal femur? (2) How does this complication profile compare with stabilization of pathologic fractures adjusted for differences in patient demographics and comorbidity? METHODS: We performed a retrospective study using the National Surgical Quality Improvement Program (NSQIP) database. We identified patients undergoing prophylactic treatment of the femoral shaft or distal femur by Current Procedural Terminology (CPT) codes. Patients undergoing treatment of a pathologic fracture were identified by CPT code for femur fracture fixation as well as an International Classification of Diseases code indicating neoplasm or pathologic fracture. We tracked adverse events, operative time, blood transfusion, hospital length of stay, and discharge to a facility within 30 days postoperatively. There were 332 patients included in the prophylactic treatment group and 288 patients in the pathologic fracture group. Patients in the prophylactic treatment group presented with greater body mass index (BMI), whereas the pathologic fracture group presented with a greater incidence of disseminated cancer. The odds of experiencing adverse events were initially compared between the two groups using bivariate logistic regression and then using multivariate regression controlling for age, sex, BMI, and American Society of Anesthesiologists (ASA) class and disseminated cancer causing marked physiological compromise per NSQIP guidelines. RESULTS: With multivariate analysis controlling for age, sex, BMI, and ASA class, patients with pathologic fracture were more likely to experience any adverse event (odds ratio [OR], 1.53; 95% confidence interval [CI], 1.03-2.29; p = 0.036), major adverse events (OR, 1.61; 95% CI, 1.01-2.55; p = 0.043), death (OR, 1.90; 95% CI, 1.07-3.38; p = 0.030), blood transfusion (OR, 1.57; 95% CI, 1.08-2.27; p = 0.017), and hospital stay ≥ 9 days (OR, 1.51; 95% CI, 1.05-2.19; p = 0.028) compared with patients undergoing prophylactic treatment. However, when additionally controlling for disseminated cancer, the only difference was that patients with pathologic fractures were more likely to receive a blood transfusion than were patients undergoing prophylactic fixation (OR, 1.61; 95% CI, 1.12-2.36; p = 0.011). CONCLUSIONS: After controlling for differences in patient characteristics, prophylactic treatment of femoral metastases was associated with a decreased likelihood of blood transfusion and no differences in terms of the frequency of other adverse events. In the context of prior studies supporting the mechanical and functional outcomes of prophylactic treatment, the findings of this cohort suggest that the current guidelines have achieved a reasonable balance of morbidity in patients with femoral lesions and further support the current role of prophylactic treatment of impending femur fractures in appropriately selected patients. LEVEL OF EVIDENCE: Level III, therapeutic study.

How Common-and How Serious- Is Clostridium difficile Colitis After Geriatric Hip Fracture? Findings from the NSQIP Dataset.

BACKGROUND: Patients with geriatric hip fractures may be at increased risk for postoperative Clostridium difficile colitis, which can cause severe morbidity and can influence hospital quality metrics. However, to our knowledge, no large database study has calculated the incidence of, factors associated with, and effect of C. difficile colitis on geriatric patients undergoing hip fracture surgery. QUESTIONS/PURPOSES: To use a large national database with in-hospital and postdischarge data (National Surgical Quality Improvement Program [NSQIP®]) to (1) determine the incidence and timing of C. difficile colitis in geriatric patients who underwent surgery for hip fracture, (2) identify preoperative and postoperative factors associated with the development of C. difficile colitis in these patients, and (3) test for an association between C. difficile colitis and postoperative length of stay, 30-day readmission, and 30-day mortality. PATIENTS AND METHODS: This is a retrospective study. Patients who were 65 years or older who underwent hip fracture surgery were identified in the 2015 NSQIP database. The primary outcome was a diagnosis of C. difficile colitis during the 30-day postoperative period. Preoperative and procedural factors were tested for association with the development of C. difficile colitis through a backward stepwise multivariate model. Perioperative antibiotic type and duration were not included in the model, as this information was not recorded in the NSQIP. The association between C. difficile colitis and postoperative length of stay, 30-day readmission, and 30-day mortality were tested through multivariate regressions, which adjusted for preoperative and procedural characteristics such as age, comorbidities, and surgical procedure. A total of 6928 patients who were 65 years or older and underwent hip fracture surgery were identified. RESULTS: The incidence of postoperative C. difficile colitis was 1.05% (95% CI, 0.81%-1.29%; 73 of 6928 patients). Of patients who had C. difficile colitis develop, 64% (47 of 73 patients) were diagnosed postdischarge and 79% (58 of 73 patients) did not have a preceding infectious diagnosis. Preoperative factors identifiable before surgery that were associated with the development of C. difficile colitis included admission from any type of chronic care facility (versus admitted from home; relative risk [RR] = 1.98; 95% CI, 1.11-3.55; p = 0.027), current smoker within 1 year (RR = 1.95; 95% CI, 1.03-3.69; p = 0.041), and preoperative anemia (RR = 1.76; 95% CI, 1.07-2.92; p = 0.027). Patients who had pneumonia (RR = 2.58; 95% CI, 1.20-5.53; p = 0.015), sepsis (RR = 4.20; 95% CI, 1.27-13.82; p = 0.018), or "any infection" (RR = 2.26; 95% CI, 1.26-4.03; p = 0.006) develop after hip fracture were more likely to have C. difficile colitis develop. Development of C. difficile colitis was associated with greater postoperative length of stay (22 versus 5 days; p < 0.001), 30-day readmission (RR = 3.41; 95% CI, 2.17-5.36; p < 0.001), and 30-day mortality (15% [11 of 73 patients] versus 6% [439 of 6855 patients]; RR = 2.16; 95% CI, 1.22-3.80; p = 0.008). CONCLUSIONS: C. difficile colitis is a serious infection after hip fracture surgery in geriatric patients that is associated with 15% mortality. Patients at high risk, such as those admitted from any type of chronic care facility, those who had preoperative anemia, and current smokers within 1 year, should be targeted with preventative measures. From previous studies, these measures include enforcing strict hand hygiene with soap and water (not alcohol sanitizers) if a provider is caring for patients at high risk and those who are C. difficile-positive. Further, other studies have shown that certain antibiotics, such as fluoroquinolones and cephalosporins, can predispose patients to C. difficile colitis. These medications perhaps should be avoided when prescribing prophylactic antibiotics or managing infections in patients at high risk. Future prospective studies should aim to determine the best prophylactic antibiotic regimens, probiotic formula, and discharge timing that minimize postoperative C. difficile colitis in patients with hip fractures. LEVEL OF EVIDENCE: Level III, therapeutic study.

The Rothman Index Is Associated With Postdischarge Adverse Events After Hip Fracture Surgery in Geriatric Patients.

BACKGROUND: The Rothman Index is a comprehensive measure of overall patient status in the inpatient setting already in use at many medical centers. It ranges from 100 (best score) to -91 (worst score) and is calculated based on 26 variables encompassing vital signs, routine laboratory values, and organ system assessments from nursing rounds from the electronic medical record. Past research has shown an association of Rothman Index with complications, readmission, and death in certain populations, but it has not been evaluated in geriatric patients with hip fractures, a potentially vulnerable patient population. QUESTIONS/PURPOSES: (1) Is there an association between Rothman Index scores and postdischarge adverse events in a population aged 65 years and older with hip fractures? (2) What is the discriminative ability of Rothman Index scores in determining which patients will or will not experience these adverse events? (3) Are there Rothman Index thresholds associated with increased incidence of postdischarge adverse outcomes? METHODS: One thousand two hundred fourteen patients aged 65 years and older who underwent hip fracture surgery at an academic medical center between 2013 and 2016 were identified. Demographic and comorbidity characteristics were characterized, and 30-day postdischarge adverse events were calculated. The associations between a 10-unit change in Rothman Index scores and postdischarge adverse events, mortality, and readmission were determined. American Society of Anesthesiologists (ASA) class was used as a measure of comorbidity because prior research has shown its performance to be equivalent or superior to that of calculated comorbidity measures in this data set. We assessed the ability of Rothman Index scores to determine which patients experienced adverse events. Finally, Rothman Index thresholds were assessed for an association with increased incidence of postdischarge adverse outcomes. RESULTS: We found a strong association between Rothman Index scores and postdischarge adverse events (lowest score: odds ratio [OR] = 1.29 [1.18-1.41], p < 0.001; latest score: OR = 1.37 [1.24-1.52], p < 0.001) after controlling for age, sex, body mass index, ASA class, and surgical procedure performed. The discriminative ability of lowest and latest Rothman Index scores was better than those of age, sex, and ASA class for any adverse event (lowest value: area under the curve [AUC] = 0.641; 95% confidence interval [CI], 0.601-0.681; latest value: AUC = 0.640; 95% CI, 0.600-0.680); age (0.534; 95% CI, 0.493-0.575, p < 0.001 for both), male sex (0.552; 95% CI, 0.518-0.585, p = 0.001 for both), and ASA class (0.578; 95% CI, 0.542-0.614; p = 0.004 for lowest Rothman Index, p = 0.006 for latest Rothman Index). There was never a difference when comparing lowest Rothman Index value and latest Rothman Index value for any of the outcomes (Table 5). Patients experienced increased rates of postdischarge adverse events and mortality with a lowest Rothman Index of ≤ 35 (p < 0.05) or latest Rothman Index of ≤ 55 (p < 0.05). CONCLUSIONS: The Rothman Index provides an objective method of assessing perioperative risk in the setting of hip fracture surgery in patients older than age 65 years and is more accurate than demographic measures or ASA class. Furthermore, there are Rothman Index thresholds that can be used to identify patients at increased risk of complications. Physicians can use this tool to monitor the condition of patients with hip fracture, recognize patients at high risk of adverse events to consider changing their plan of care, and counsel patients and families. Further investigation is needed to determine whether interventions based on Rothman Index values contribute to improved outcomes or value of hip fracture care. LEVEL OF EVIDENCE: Level II, diagnostic study.

Similar 30-Day Complications for Septic Knee Arthritis Treated With Arthrotomy or Arthroscopy: An American College of Surgeons National Surgical Quality Improvement Program Analysis.

PURPOSE: The purpose of the current study was to use the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) to determine whether there were differences in 30-day perioperative complications between open arthrotomy and arthroscopy for the treatment of septic knees in a large national sample. METHODS: Patients who were diagnosed with a septic knee and underwent open arthrotomy or arthroscopy were identified in the 2005-2014 NSQIP data sets. Patient demographics and perioperative complications were characterized and compared between the 2 procedures. RESULTS: In total, 168 patients undergoing knee arthrotomy and 216 patients undergoing knee arthroscopy for septic knee were identified. There were no statistically significant differences in demographic variables between the 2 groups. On univariate analysis, the rate of minor adverse events (MAEs; 15.48% vs 8.80%, P = .043) was higher in the open arthrotomy treatment group, while the rate of serious adverse events (SAEs; 37.50% vs 26.19%, P = .019) was higher in the arthroscopic surgery treatment group. On multivariate analysis, which controlled for patient characteristics/comorbidities and used the Bonferroni correction for multiple comparisons, there were no statistically significant differences in risk of any adverse events (relative risk [RR] = 0.851; 99% confidence interval [CI], 0.598-1.211; P = .240), MAE (RR = 1.653; 99% CI, 0.818-3.341; P = .066), SAE (RR = 0.706; 99% CI, 0.471-1.058; P = .027), return to the operating room (RR = 0.810; 99% CI, 0.433-1.516; P = .387), or readmission (RR = 1.022; 99% CI, 0.456-2.294; P = .944) between open compared with arthroscopic surgery. CONCLUSIONS: Univariate analysis revealed a lower rate of MAE but a higher rate of SAE in the arthroscopic surgery treatment group. However, on multivariate analysis, similar perioperative complications, rate of return to the operating room, and rate of readmission were found after open and arthroscopic debridement for septic knees. Based on the lack of demonstrated superiority of either of these 2 treatment modalities for this given diagnosis, and the expectation that most differences in perioperative complications for this diagnosis would have declared themselves within the first 30 days, deciding between the studied treatment modalities may be based more on other factors not included in this study. LEVEL OF EVIDENCE: Retrospective comparative study, Level III.

Treatments of Missing Values in Large National Data Affect Conclusions: The Impact of Multiple Imputation on Arthroplasty Research.

BACKGROUND: Despite the advantages of large, national datasets, one continuing concern is missing data values. Complete case analysis, where only cases with complete data are analyzed, is commonly used rather than more statistically rigorous approaches such as multiple imputation. This study characterizes the potential selection bias introduced using complete case analysis and compares the results of common regressions using both techniques following unicompartmental knee arthroplasty. METHODS: Patients undergoing unicompartmental knee arthroplasty were extracted from the 2005 to 2015 National Surgical Quality Improvement Program. As examples, the demographics of patients with and without missing preoperative albumin and hematocrit values were compared. Missing data were then treated with both complete case analysis and multiple imputation (an approach that reproduces the variation and associations that would have been present in a full dataset) and the conclusions of common regressions for adverse outcomes were compared. RESULTS: A total of 6117 patients were included, of which 56.7% were missing at least one value. Younger, female, and healthier patients were more likely to have missing preoperative albumin and hematocrit values. The use of complete case analysis removed 3467 patients from the study in comparison with multiple imputation which included all 6117 patients. The 2 methods of handling missing values led to differing associations of low preoperative laboratory values with commonly studied adverse outcomes. CONCLUSION: The use of complete case analysis can introduce selection bias and may lead to different conclusions in comparison with the statistically rigorous multiple imputation approach. Joint surgeons should consider the methods of handling missing values when interpreting arthroplasty research.

Impact of Operative Time on Adverse Events Following Primary Total Joint Arthroplasty.

BACKGROUND: Little is known regarding the impact of operative time on adverse events following arthroplasty. The present study tests for associations between a 15-minute increase in operative time and the occurrence of adverse events following primary total joint arthroplasty. METHODS: Patients undergoing primary total hip or knee arthroplasty during 2006-2013 were identified in the American College of Surgeons National Surgical Quality Improvement Program. Operative time (as a continuous variable) was tested for association with perioperative outcomes using multivariate regression. All regressions were adjusted for differences in demographic, comorbidity, and procedural characteristics. RESULTS: A total of 165,474 patients met inclusion criteria. The mean (±standard deviation) operative time was 91.9 ± 32.5 minutes. Following adjustment for baseline characteristics, an increase in operative time by 15 minutes increased the risk of anemia requiring transfusion by 9% (95% confidence interval [CI] = 8%-10%, P < .001), wound dehiscence by 13% (95% CI = 8%-19%, P < .001), renal insufficiency by 9% (95% CI = 3%-14%, P < .001), sepsis by 10% (95% CI = 6%-14%, P < .001), surgical site infection by 9% (95% CI = 7%-12%, P < .001), and urinary tract infection by 4% (95% CI = 2%-6%, P < .001). Similarly, an increase in operative time by 15 minutes increased the risk of hospital readmission by 5% (95% CI = 4%-6%, P < .001) and of extended hospital length of stay (≥4 days) by 9% (95% CI = 8%-10%, P < .001). CONCLUSION: The present study suggests that greater operative time increases the risk for multiple postoperative complications following total joint arthroplasty. These data suggest that surgeons should consider steps to minimize operative time without compromising the technical components of the surgical procedure.

Discriminative Ability of Elixhauser's Comorbidity Measure is Superior to Other Comorbidity Scores for Inpatient Adverse Outcomes After Total Hip Arthroplasty.

BACKGROUND: Identifying patients at highest risk for a complex perioperative course following total hip arthroplasty (THA) is more important than ever in order to educate patients, optimize outcomes, and to minimize cost and length of stay. There are no known studies comparing the clinically relevant discriminative ability of 3 commonly used comorbidity indices for adverse outcomes following THA: Elixhauser Comorbidity Measure (ECM), the Charlson Comorbidity Index (CCI), and the modified Frailty Index (mFI). METHODS: Patients undergoing THA were extracted from the 2013 National Inpatient Sample. The discriminative ability of ECM, CCI, and mFI, as well as the demographic factors age, body mass index, and gender for the occurrence of index admission Centers for Medicare & Medicaid Services procedure-specific complication measures, extended length of hospital stay, and discharge to a facility were assessed using the area under the curve analysis from receiver operating characteristic curves. RESULTS: ECM outperformed CCI and mFI for the occurrence of all 5 adverse outcomes. Age outperformed gender and obesity for the occurrence of all 5 adverse outcomes. ECM (the best performing comorbidity index) outperformed age (the best performing demographic factor) in discriminative ability for the occurrence of 3 of 5 adverse outcomes. CONCLUSION: The less commonly used ECM outperformed the more often utilized CCI and newer mFI as well as demographic factors in correctly preoperatively identifying patients' probabilities of experiencing an adverse outcome suggesting that wider adoption of ECM should be considered in both identifying likelihoods of adverse patient outcomes and for research purposes in future studies.

Revision Total Knee Arthroplasty in Octogenarians: An Analysis of 957 Cases.

BACKGROUND: The number of octogenarians undergoing revision total knee arthroplasty (TKA) is increasing. However, there has been a lack of studies investigating the perioperative course and safety of revision TKA performed in this potentially vulnerable population in a large patient population. The purpose of this study is to compare complications following revision TKA between octogenarians and 2 younger patient populations (<70 and 70-79 year olds). METHODS: Patients who underwent revision TKA were identified in the 2005-2015 National Surgical Quality Improvement Program database and stratified into 3 age groups: <70, 70-79, and ≥80 years. Baseline preoperative and intraoperative characteristics were compared between the 3 groups. Propensity score matched comparisons were then performed for 30-day perioperative complications, length of hospital stay, and readmissions. RESULTS: This study included 6523 (<70 years), 2509 (70-79 years), and 957 octogenarian patients who underwent revision TKA. After propensity matching, statistical analysis revealed only higher rates of blood transfusion and slightly longer length of stay in octogenarians compared to <70 year olds. Similarly, octogenarians had only higher rates of blood transfusion and slightly longer length of stay compared to 70-79 year olds. Notably, there were no differences in mortality or readmission between octogenarians compared to younger populations. CONCLUSION: These data suggest that revision TKA can safely be considered for octogenarians with the observation of higher rates of blood transfusion and slightly longer length of stay compared to younger populations. Octogenarian patients need not be discouraged from revision TKA solely based on their advanced age.

What Is the Timing of General Health Adverse Events That Occur After Total Joint Arthroplasty?

BACKGROUND: Despite extensive research regarding risk factors for adverse events after total joint arthroplasty (TJA), there are few publications describing the timing at which such adverse events occur. QUESTIONS/PURPOSES: (1) On which postoperative day do certain adverse events occur? (2) What adverse events occur earlier after TKA than after THA? (3) For each adverse event, what proportion occurred after hospital discharge? METHODS: We screened the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) to identify all patients undergoing primary THA and primary TKA between 2005 and 2013, resulting in a study population of 124,657 patients evaluated as part of this retrospective database analysis. For each of eight different adverse events, the median postoperative day of diagnosis, interquartile range for day of diagnosis, and middle 80% for day of diagnosis were determined. Multivariate Cox proportional hazards modeling was used to test whether there is a difference of timing for each adverse event as stratified by TKA or THA. The proportion of adverse events occurring after versus before discharge was also calculated. RESULTS: The median day of diagnosis (and interquartile range; middle 80%) for stroke was 2 (1-10; 1-19), myocardial infarction 3 (2-6; 1-15), pulmonary embolism 3 (2-7; 1-19), pneumonia 4 (2-9; 2-17), deep vein thrombosis 6 (3-14; 2-23), urinary tract infection 8 (3-16; 2-24), sepsis 10 (5-19; 2-24), and surgical site infection 17 (11-23; 6-28). For the later occurring adverse events (surgical site infection, sepsis), the rate of occurrence remained high at the end of the 30-day postoperative period. Timing was earlier in patients undergoing TKA for pulmonary embolism (day 3 [interquartile range 2-6] versus 5 [3-17], p < 0.001) and deep vein thrombosis (day 5 [2-11] versus 13 [6-22], p < 0.001). The proportion of events occurring after discharge for myocardial infarction was 97 of 283 (34%), stroke 42 of 118 (36%), pulmonary embolism 223 of 625 (36%), pneumonia 171 of 426 (40%), deep vein thrombosis 576 of 956 (60%), urinary tract infection 958 of 1406 (68%), sepsis 284 of 416 (68%), and surgical site infection 1147 of 1212 (95%). CONCLUSIONS: As lengths of hospital stay after TJA continue to decrease, our findings suggest that caution is in order because several acute and immediately life-threatening findings, including myocardial infarction and pulmonary embolism, might occur after discharge. Furthermore, the timing of surgical site infection and sepsis suggests that even the 30-day followup afforded by the ACS-NSQIP may not be sufficient to study the latest occurring adverse events. Additionally, both pulmonary embolism and deep vein thrombosis tend to occur earlier after TKA than THA, and this should guide clinical surveillance efforts in patients undergoing those procedures. These findings also indicate that inpatient-only databases (such as the Nationwide Inpatient Sample) may fail to capture a very large proportion of postoperative adverse events, weakening the conclusions of many published studies using those databases. LEVEL OF EVIDENCE: Level III, therapeutic study.

Definitional Differences of 'Outpatient' Versus 'Inpatient' THA and TKA Can Affect Study Outcomes.

BACKGROUND: There has been great interest in performing outpatient THA and TKA. Studies have compared such procedures done as outpatients versus inpatients. However, stated "outpatient" status as defined by large national databases such as the National Surgical Quality Improvement Program (NSQIP) may not be a consistent entity, and the actual lengths of stay of those patients categorized as outpatients in NSQIP have not been specifically ascertained and may in fact include some patients who are "observed" for one or more nights. Current regulations in the United States allow these "observed" patients to stay more than one night at the hospital under observation status despite being coded as outpatients. Determining the degree to which this is the case, and what, exactly, "outpatient" means in the NSQIP, may influence the way clinicians read studies from that source and the way hospital systems and policymakers use those data. QUESTIONS/PURPOSES: The purposes of this study were (1) to utilize the NSQIP database to characterize the differences in definition of "inpatient" and "outpatient" (stated status versus actual length of stay [LOS], measured in days) for THA and TKA; and (2) to study the effect of defining populations using different definitions. METHODS: Patients who underwent THA and TKA in the 2005 to 2014 NSQIP database were identified. Outpatient procedures were defined as either hospital LOS = 0 days in NSQIP or being termed "outpatient" by the hospital. The actual hospital LOS of "outpatients" was characterized. "Outpatients" were considered to have stayed overnight if they had a LOS of 1 day or longer. The effects of the different definitions on 30-day outcomes were evaluated using multivariate analysis while controlling for potential confounding factors. RESULTS: Of 72,651 patients undergoing THA, 529 were identified as "outpatients" but only 63 of these (12%) had a LOS = 0. Of 117,454 patients undergoing TKA, 890 were identified as "outpatients" but only 95 of these (11%) had a LOS = 0. After controlling for potential confounding factors such as gender, body mass index, functional status before surgery, comorbidities, and smoking status, we found "inpatient" THA to be associated with increased risk of any adverse event (relative risk, 2.643, p = 0.002), serious adverse event (relative risk, 2.455, p = 0.011), and readmission (relative risk, 2.775, p = 0.010) compared with "outpatient" THA. However, for the same procedure and controlling for the same factors, patients who had LOS > 0 were not associated with any increased risk compared with patients who had LOS = 0. A similar trend was also found in the TKA cohort. CONCLUSIONS: Future THA, TKA, or other investigations on this topic should consistently quantify the term "outpatient" because different definitions, stated status or actual LOS, may lead to different assignments of risk factors for postoperative complications. Accurate data regarding risk factors for complications after total joint arthroplasty are crucial for efforts to reduce length of hospital stay and minimize complications. LEVEL OF EVIDENCE: Level III, therapeutic study.