Role of femoral head material on readmission and mortality rates following elective primary total hip arthroplasty in Medicare patients.

INTRODUCTION: The role of different femoral head materials for total hip arthroplasty (THA) has been widely studied in the context of wear properties and corrosion. Cobalt chrome (CoCr) femoral heads are commonly used as a standard of comparison to other materials such as ceramic and oxidized zirconium (OxZi). This study aims to evaluate the impact of femoral head material on clinical outcomes in elective primary THA patients. METHODS: Retrospective analysis of THA patients within the Medicare claims database between October 2017 and September 2020 using diagnosis-related group codes was conducted. Information collected included sex, age, Charlson Comorbidity Index, and femoral head type. Patients with CoCr femoral heads were compared against patients with either OxZi or ceramic femoral heads using 1:1 propensity score matching. Z-testing and Chi-square analysis were used to determine between-group significance. RESULTS: In total, 112,960 elective THA patients were included, with 56,480 in OxZi or ceramic and 56,480 in CoCr. Readmission rates were lower in patients that received OxZi or ceramic femoral heads at 30-day (p < 0.0001), 60-day (p < 0.0001), and 90-day postoperatively (p < 0.0001) compared to CoCr. Mortality rates were also lower in patients that received OxZi or ceramic femoral heads at 30-day (p = 0.004), 60-day (p = 0.018), and 90-day postoperatively (p = 0.009) compared to CoCr. CONCLUSION: CoCr femoral heads had higher rates of readmissions and mortality compared to OxZi or ceramic. Further analysis of bearing surface combinations and sub-group analyses to determine significance between-group differences is needed. LEVEL III EVIDENCE: Retrospective analysis.

Indications, Clinical Outcomes, and Re-Revisions Following Revision Total Hip Arthroplasty - Does Age Matter?

BACKGROUND: Younger age is associated with increased revision incidence following primary total hip arthroplasty, though the association between age and repeat revision following revision total hip arthroplasty (rTHA) has not been described. This study aimed to describe the incidences and indications for subsequent revision (re-revision) following rTHA based on age. METHODS: Patients undergoing aseptic rTHA from 2011 to 2021 with minimum 1-year follow-up were retrospectively reviewed. Patients were stratified into 3 groups based on age at the time of index rTHA (ie, <55 years, 55 to 74 years, and >74 years). Perioperative characteristics, complications, and re-revisions were compared between groups. RESULTS: Of 694 included rTHAs, those in the >74 age group were more likely to undergo rTHA for periprosthetic fracture (P < .001) while those in the <55 age group were more likely to undergo rTHA for metallosis/taper corrosion (P = .028). Readmissions (P = .759) and emergency department visits (P = .498) within 90 days were comparable across ages. Rates of re-revision were comparable at 90 days (P = .495), 1 year (P = .443), and 2 years (P = .204). Kaplan-Meier analysis of all-cause re-revision at latest follow-up showed a nonstatistically significant trend toward increasing re-revisions in the <55 and 55 to 74 age groups. Using logistic regressions, smoking and index rTHA for instability were independently associated with re-revision, while age at index surgery was not. CONCLUSIONS: While indications for rTHA differ across age groups, rates of 2-year re-revision are statistically comparable between groups. Further studies are warranted to understand the association between age, activity, and re-revision rates after 5 years postoperatively.

The Effect of Surgeon and Hospital Volume on Total Knee Arthroplasty Patient-reported Outcome Measures: An American Joint Replacement Registry Study.

BACKGROUND: The lower morbidity and mortality rate associated with increased surgeon and hospital volume may also correlate with improved patient-reported outcome measures. The goal of this study was to determine the relationship between surgeon and hospital volume and patient-reported outcome measures after total knee arthroplasty (TKA) using American Joint Replacement Registry data. METHODS: Using American Joint Replacement Registry data from 2012 to 2020, 8,193 primary, elective TKAs with both preoperative and 1-year postoperative The Knee Injury and Osteoarthritis Outcome Score, Joint Replacement (KOOS-JR) scores were analyzed. This study was powered to detect the minimally clinical important difference (MCID). The main exposure variables were median annual surgeon and hospital volume. Tertiles were formed based on the median annual number of TKAs performed: low-volume surgeons (1 to 52), medium-volume (53 to 114), and high-volume (≥115); low-volume hospitals (1 to 283), medium-volume (284 to 602), and high-volume (≥603). The mean preoperative and 1-year postoperative KOOS-JR were compared. Multivariable logistic regression models were used to determine the effect of surgeon and hospital volume and demographics on achieving the MCID for KOOS-JR. RESULTS: The mean preoperative and 1-year postoperative KOOS-JR score for low-volume surgeons was 47.78 ± 13.50 and 77.75 ± 16.65, respectively, and 47.32 ± 13.73 and 76.86 ± 16.38 for low-volume hospitals. The mean preoperative and 1-year postoperative KOOS-JR score for medium-volume surgeons was 47.20 ± 13.46 and 76.70 ± 16.98, and 48.93 ± 12.50 and 77.15 ± 16.36 for medium-volume hospitals. The mean preoperative and 1-year postoperative KOOS-JR scores for high-volume surgeons were 49.08 ± 13.04 and 78.23 ± 16.72, and 48.11 ± 13.47 and 78.23 ± 17.22 for high-volume hospitals. No notable difference was observed in reaching MCID for KOOS-JR after adjustment for potential confounders. CONCLUSION: An increased number of TKA cases performed by a given surgeon or at a given hospital did not have an effect on achieving MCID for KOOS-JR outcomes.

Outcomes of medicaid patients undergoing TJA with previous positive urine toxicology screens.

INTRODUCTION: Previous studies have demonstrated that patients with positive preoperative urine toxicology (utox) screens prior to total joint arthroplasty (TJA) have higher readmission rates, greater complication rates, and longer hospital stays compared to patients with negative screens. The aim of this study was to investigate the effect of postponing surgery for patients with positive preoperative utox in the Medicaid population. METHODS: This retrospective, observational study reviewed the Medicaid ambulatory database at a large, academic orthopedic specialty hospital for patients with a utox screen prior to TJA from 2012 to 2020. Patients were categorized into three groups: (1) controls with negative preoperative utox or a utox consistent with prescription medications (Utox-) with TJA completed as scheduled; (2) positive preoperative utox with TJA rescheduled and surgery completed on a later date (R-utox+); (3) positive preoperative utox inconsistent with prescription medications with TJA completed as scheduled (S-utox+). Primary outcomes included mortality, 90-day readmission rate, complication rate, and length of stay. RESULTS: Of the 300 records reviewed, 185 did not meet inclusion criteria. The remaining 115 patients included 80 (69.6%) Utox-, 5 (6.3%) R-utox+, and 30 (37.5%) S-utox+. Mean follow-up time was 49.6 months. Hospital stays trended longer in the Utox- group (3.7 ± 2.0 days vs. 3.1 ± 1.6 S-utox+ vs.2.5 ± 0.4 R-utox+, p = 0.20). Compared to the R-utox+group, the S-utox+ group trended toward lower home discharge rates (p = 0.20), higher in-hospital complication rates (p = 0.85), and more all-cause 90-day emergency department visits (p = 0.57). There were no differences in postoperative opioid utilization between groups (p = 0.319). Duration of postoperative narcotic use trended toward being longer in the Utox- patients (820.7 ± 1073.8 days vs. 684.6 ± 1491.8 S-utox+ vs. 585.1 ± 948.3 R-utox+, p = 0.585). Surgical time (p = 0.045) and revision rates (p = 0.72) trended toward being higher in the S-utox+ group. CONCLUSIONS: Medicaid patients with positive preoperative utox who had surgeries postponed trended towards shorter hospital stays and greater home discharge rates. Larger studies should be conducted to analyze the implications of a positive preoperative utox on risk profiles and outcomes following TJA in the Medicaid population. Study design Retrospective cohort study.

Larger operating rooms have better air quality than smaller rooms in primary total knee arthroplasty.

INTRODUCTION: Operating room air quality can be affected by several factors including temperature, humidity, and airborne particle burden. Our study examines the role of operating room (OR) size on air quality and airborne particle (ABP) count in primary total knee arthroplasty (TKA). MATERIALS AND METHODS: We analyzed all primary, elective TKAs performed within two ORs measuring 278 sq ft. (small) and 501 sq ft. (large) at a single academic institution in the United States from April 2019 to June 2020. Intraoperative measurements of temperature, humidity, and ABP count were recorded. p values were calculated using t test for continuous variables and chi-square for categorical values. RESULTS: 91 primary TKA cases were included in the study, with 21 (23.1%) in the small OR and 70 (76.9%) in the large OR. Between-groups comparisons revealed significant differences in relative humidity (small OR 38.5% ± 7.24% vs. large OR 44.4% ± 8.01%, p = 0.002). Significant percent decreases in ABP rates for particles measuring 2.5 µm (- 43.9%, p = 0.007) and 5.0 µm (- 69.0%, p = 0.0024) were found in the large OR. Total time spent in the OR was not significantly different between the two groups (small OR 153.09 ± 22.3 vs. large OR 173 ± 44.6, p = 0.05). CONCLUSIONS: Although total time spent in the room did not differ between the large and small OR, there were significant differences in humidity and ABP rates for particles measuring 2.5 µm and 5.0 µm, suggesting the filtration system encounters less particle burden in larger rooms. Larger studies are required to determine the impact this may have on OR sterility and infection rates.

Aspirin Thromboprophylaxis Following Primary Total Knee Arthroplasty Is Associated With a Lower Rate of Early Prosthetic Joint Infection Compared With Other Agents.

BACKGROUND: Patients undergoing total knee arthroplasty (TKA) are at increased risk of venous thromboembolism (VTE). Aspirin has been shown to be effective at reducing rates of VTE. In select patients, more potent thromboprophylaxis is indicated, which has been associated with increased rates of bleeding and wound complications. This study aimed to evaluate the effect of thromboprophylaxis choice on the rates of early prosthetic joint infection (PJI) following TKA. METHODS: A review of 11,547 primary TKA patients from 2013 to 2019 at a single academic orthopaedic hospital was conducted. The primary outcome measure was PJI within 90 days of surgery as measured by Musculoskeletal Infection Society criteria. There were 59 (0.5%) patients diagnosed with early PJI. Chi-square and Welch-2 sample t-tests were used to determine statistically significant relationships between thromboprophylaxis and demographic variables. Significance was set at P < .05. Multivariate logistic regression adjusted for age, body mass index, sex, and Charlson comorbidity index was performed to identify and control for independent risk factors for early PJI. RESULTS: There was a statistically significant difference in the rates of early PJI between the aspirin and non-aspirin group (0.3 versus 0.8%, P < .001). Multivariate logistic regressions revealed that patients given aspirin thromboprophylaxis had significantly lower odds of PJI (odds ratios = 0.51, 95% confidence interval = 0.29-0.89, P = .019) compared to non-aspirin patients. CONCLUSION: The use of aspirin thromboprophylaxis following primary TKA is independently associated with a lower rate of early PJIs. Arthroplasty surgeons should consider aspirin as the gold standard thromboprophylaxis in all patients in which it is deemed medically appropriate and should carefully weigh the morbidity of PJI in patients when non-aspirin thromboprophylaxis is considered. LEVEL OF EVIDENCE: Retrospective, Therapeutic Level III.

Role of Operating Room Size on Air Quality in Primary Total Hip Arthroplasty.

BACKGROUND: Airborne biologic particles (ABPs) can be measured intraoperatively to evaluate operating room (OR) sterility. Our study examines the role of OR size on air quality and ABP count in primary total hip arthroplasty (THA). METHODS: We analyzed primary THA procedures done within 2 ORs measuring 278 ft2 and 501 ft2 at a single academic institution from April 2019 to June 2020. Temperature, humidity, and ABP count per minute were recorded with a particle counter intraoperatively and cross-referenced with surgical data from the electronic health records using procedure start and end times. Descriptive statistics were used to evaluate differences in variables. P-values were calculated using t-test and chi-squared test. RESULTS: A total of 116 primary THA cases were included: 18 (15.5%) in the "small" OR and 98 (84.5%) in the "large" OR. Between-group comparisons revealed significant differences in temperature (small OR: 20.3 ± 1.23 C versus large OR: 19.1 ± 0.85 C, P < .0001) and relative humidity (small OR: 41.1 ± 7.24 versus large OR: 46.9 ± 7.56, P < .001). Significant percent decreases in ABP rates for particles measuring 2.5 um (-125.0%, P = .0032), 5.0 um (-245.0%, P = .00078), and 10.0 um (-413.9%, P = .0021) were found in the large OR. Average time spent in the OR was significantly longer in the large OR (174 ± 33 minutes) compared to the small OR (151 ± 14 minutes) (P = .00083). CONCLUSION: Temperature and humidity differences and significantly lower ABP counts were found in the large compared to the small OR despite longer average time spent in the large OR, suggesting the filtration system encounters less particle burden in larger rooms. Further research is needed to determine the impact this may have on infection rates.

A Validated Pre-operative Risk Prediction Tool for Extended Inpatient Length of Stay Following Primary Total Hip or Knee Arthroplasty.

BACKGROUND: As value-based reimbursement models mature, understanding the potential trade-off between inpatient lengths of stay and complications or need for costly postacute care becomes more pressing. Understanding and predicting a patient's expected baseline length of stay may help providers understand how best to decide optimal discharge timing for high-risk total joint arthroplasty (TJA) patients. METHODS: A retrospective review was conducted of 37,406 primary total hip (17,134, 46%) and knee (20,272, 54%) arthroplasties performed at two high-volume, geographically diverse, tertiary health systems during the study period. Patients were stratified by 3 binary outcomes for extended inpatient length of stay: 72 + hours (29%), 4 + days (11%), or 5 + days (5%). The predictive ability of over 50 sociodemographic/comorbidity variables was tested. Multivariable logistic regression models were created using institution #1 (derivation), with accuracy tested using the cohort from institution #2 (validation). RESULTS: During the study period, patients underwent an extended length of stay with a decreasing frequency over time, with privately insured patients having a significantly shorter length of stay relative to those with Medicare (1.9 versus 2.3 days, P < .0001). Extended stay patients also had significantly higher 90-day readmission rates (P < .0001), even when excluding those discharged to postacute care (P < .01). Multivariable logistic regression models created from the training cohort demonstrated excellent accuracy (area under the curve (AUC): 0.755, 0.783, 0.810) and performed well under external validation (AUC: 0.719, 0.743, 0.763). Many important variables were common to all 3 models, including age, sex, American Society of Anesthesiologists (ASA) score, body mass index, marital status, bilateral case, insurance type, and 13 comorbidities. DISCUSSION: An online, freely available, preoperative clinical decision tool accurately predicts risk of extended inpatient length of stay after TJA. Many risk factors are potentially modifiable, and these validated tools may help guide clinicians in preoperative patient counseling, medical optimization, and understanding optimal discharge timing.

Outcomes After Arthroscopic Revision Bankart Repair: An Updated Systematic Review of Recent Literature.

PURPOSE: To provide an update of recent literature with a specialized focus on clinical outcomes following arthroscopic revision Bankart repair (ARBR) by performing a systematic review of all available literature published between 2013 and 2020. METHODS: A literature search reporting clinical outcomes after ARBR was performed. Criteria for inclusion consisted of original studies; Level of Evidence of I-IV; studies focusing on clinical outcomes after ARBR published between January 1, 2013, and January 4, 2021; studies reporting recurrent dislocation or instability rate after ARBR; reoperation/revision following ARBR, return to sport rates following ARBR; and patient-reported outcomes. The primary outcomes of interest were failure defined as recurrent instability or dislocation, return to sport rates, and patient-reported outcomes at follow-up. RESULTS: A large proportion of patients undergoing arthroscopic revision Bankart repair were male, ranging between 67.7% and 93.8%. Failure rate and return to sports rate ranged between 6.1% and 46.8% and 25.9% and 88.3%, respectively, when patients with significant or greater than 20% glenoid bone loss was excluded. Patient-reported outcome scores, which included American Shoulder and Elbow Surgeons, Simple Shoulder Test, and visual analog scale, saw significant improvement over mean follow-up of ranging 21.64 to 60 months. CONCLUSIONS: Both the failure rate and RTS rates after ARBR had a wide range, given the heterogeneity of the studies included, which varied in patient selection criteria pertaining to patients with greater than 20% glenoid bone. Although there have been advancements in arthroscopic techniques and a trend favoring arthroscopic stabilization procedures, there is a lack of consensus in recent literature for careful patient selection criteria that would minimize failure rates and maximize RTS rates after ARBR. LEVEL OF EVIDENCE: Level IV, a systematic review of Level III-IV studies.

Impact of preoperative opioid use on patient-reported outcomes following primary total knee arthroplasty.

PURPOSE: The previous literature suggests that 25-30% of patients who undergo total knee arthroplasty (TKA) are using opioids prior to their surgery. This study aims to investigate the effect of preoperative opioid use on clinical outcomes and patient-reported outcome measures (PROMs) following TKA. METHODS: We retrospectively reviewed 329 patients who underwent primary TKA from 2019 to 2020, answered the preoperative opioid survey, and had available PROMs. Patients were stratified into two groups based on whether they were taking opioids preoperatively or not: 26 patients with preoperative opioid use (8%) and 303 patients without preoperative opioid use (92%) were identified. Demographics, clinical data, and PROMs [Forgotten Joint Score (FJS-12), Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS, JR), and Veterans RAND-12 Physical and Mental components (VR-12 PCS and MCS)] were collected. Demographic differences were assessed with Chi-square and independent sample t-tests. Outcomes were compared using multilinear regression analysis, controlling for demographic differences. RESULTS: Preoperative opioid users had a significantly longer length-of-stay (2.74 vs. 2.10; p = 0.010), surgical time (124.65 vs. 105.69; p < 0.001), and were more likely to be African-American (38.5 vs. 14.2%; p = 0.010) compared to preoperative opioid-naive patients. Postoperative FJS-12 did not statistically differ between the two groups. While preoperative KOOS, JR scores were significantly lower for preoperative opioid users (41.10 vs. 46.63; p = 0.043), they did not significantly differ postoperatively. Preoperative VR-12 PCS did not statistically differ between the groups; however, both 3-month (33.87 vs. 38.41; p = 0.049) and 1-year (36.01 vs. 44.73; p = 0.043) scores were significantly lower for preoperative opioid users. Preoperative VR-12 MCS was significantly lower for preoperative opioid users (46.06 vs. 51.06; p = 0.049), though not statistically different postoperatively. CONCLUSION: At 8%, our study population had a lower percentage of opioid users than previously reported in the literature. Preoperative opioid users had longer operative times and length of stay compared to preoperatively opioid-naive patients. While both cohorts achieved similar clinical benefits following TKA, preoperative opioid users reported lower postoperative scores with respect to VR-12 PCS scores. LEVEL III EVIDENCE: Retrospective Cohort.

Indications for Conversion of Spinal into General Anesthesia During Total Joint Arthroplasty.

INTRODUCTION: Spinal anesthesia (SA) is the preferred method of anesthesia at many centers for total joint arthro- plasty (TJA). However, a small subset of patients fails SA, necessitating a conversion to general anesthesia (GA). This report assesses the patient characteristics associated with failed SA. METHODS: A retrospective study was conducted on patients who underwent SA during their primary TJA between Janu- ary 2015 and December 2016 at our institution. A subset of this group required a conversion from SA to GA. Anesthesia reports were reviewed for the number of attempts at SA and the documented reason for failure. The SA failure cohort was then subdivided into failure categories based on the reasons that had been provided. RESULTS: A total of 5,706 patients were included in this study, 78 of which experienced SA failure. The number of attempts was most strongly associated with SA failure, with three attempts resulting in a five times increased failure rate (OR = 4.73, p = 0.010) and four attempts resulting in 12 times increased failure rate compared to the no failure cohort (OR = 12.3, p < 0.001). Greater than two attempts occurred in 87.5% of the "technical failure" sub-group of the SA failure cohort (p < 0.001). No difference was demon- strated among the other patient characteristics, such as age, sex, body mass index, race, American Society of Anesthesia (ASA) score, and surgical time. CONCLUSIONS: The results suggest that the major predic- tor influencing spinal to general anesthesia conversion was the number of attempts at SA, especially among technical failure cases. Based on the results, it may be appropriate for anesthesiologists to convert to GA after two failed spi- nal attempts. Further studies are warranted to assess this relationship for firm clinical recommendations.

Bipolar Sealers and Tourniquet Use Have Similar Outcomes in Total Knee Arthroplasty.

Introduction: The use of tourniquets and bipolar sealers are effective methods of hemostasis during total knee arthroplasty (TKA). However, their effect on perioperative patient outcomes is unknown. The purpose of this study is to compare the efficacy of tourniquet-less, tourniquet-less with use of a bipolar sealer, and tourniquet use on postoperative pain and surgical outcomes following TKA. Methods: A retrospective study of prospectively collected data of 120 primary TKA cases was conducted at an urban academic hospital. Primary outcomes were visual analog scale (VAS) scores and opioid consumption (in morphine milligram equivalents). Demographics, length of stay (LOS), perioperative complications, and change in Knee Injury and Osteoarthritis Outcome Score (ΔKOOS) were also collected. Patients were divided into cohorts based on the use of tourniquet-less with bipolar sealer (TRLB) (n = 40), tourniquet (TR) (n = 40), or tourniquet-less (TRL) (n = 40). Results: There were no differences in demographic data between each cohort. TRLB, TR and TRL had similar LOS (2.68 ± 1.63 vs 2.29 ± 1.27 vs 2.36 ± 1.42 days; p = 0.472) and VAS pain score on postoperative day 1 (4.68 vs 3.74 vs 3.63; p = 0.209). There were also no differences in opioid consumption at 2 weeks (p = 0.903), 1 month (p = 0.973), 3 months (p = 0.983), or 5 months (p = 0.983) post-operatively. TRLB and TR had comparable improvement in ΔKOOS from baseline to 12 weeks post-operatively (Δ16.58 ± 8.47 vs Δ23.92 ± 14.60; p = 0.254). Compared to the ΔKOOS of TRL (Δ5.19 ± 2.59), TRLB and TR had clinically and statistically greater ΔKOOS improvements (p = 0.009; p = 0.001). The TRL cohort also had a higher readmission rate than TRLB and TR (15% vs 0% vs 5%, p = 0.025). Conclusion: Our findings demonstrate that both bipolar sealer and tourniquet use in TKA are associated with similar postoperative pain levels and LOS in comparison to tourniquet-less only TKA. However, bipolar sealer and tourniquet use may lead to better longer term improvement such as greater PRO score improvement and fewer readmissions.

Trends of obesity rates between primary total hip arthroplasty patients and the general population from 2013 to 2020.

BACKGROUND: The prevalence of obesity in total hip arthroplasty (THA) patients has been studied in the past. However, there has not been direct comparison against obesity in the general population. This study compared yearly trends in BMI and obesity rates between patients who had undergone primary THA and those from the general patient population. METHODS: We retrospectively reviewed all patients over the age of 18 who underwent primary, elective THA and those who had an annual routine physical exam between January 2013 and December 2020 at our academic tertiary medical center. Baseline demographics were controlled in our statistical models. Significance of yearly trends was determined through a linear regression analysis. Independent samples t-test and Chi-square test were used to compare means and proportions between the two groups, respectively. RESULTS: A total of 11,250 primary THA patients and 1,039,918 annual physical exam patients were included. Average BMI for the THA group was significantly higher (P < 0.001) each year compared to the annual physicals group (APG). Higher obesity rates were observed in all obesity subgroups (all classes, and class I-III individually) for THA patients each year compared to the APG. Interestingly, while we found a significantly increasing trend in obesity for the general population (P < 0.001), BMI and obesity rates remained stable in the THA population. CONCLUSION: While our general patient population showed significant increase in BMI and obesity over time, THA patients had higher, yet stable, BMI. Further investigation is required to determine the role of risk optimization in these findings. LEVEL III EVIDENCE: Retrospective Cohort Study.

Validation of a Predictive Tool for Discharge to Rehabilitation or a Skilled Nursing Facility After TJA.

BACKGROUND: Cost excess in bundled payment models for total joint arthroplasty (TJA) is driven by discharge to rehabilitation or a skilled nursing facility (SNF). A recently published preoperative risk prediction tool showed very good internal accuracy in stratifying patients on the basis of likelihood of discharge to an SNF or rehabilitation. The purpose of the present study was to test the accuracy of this predictive tool through external validation with use of a large cohort from an outside institution. METHODS: A total of 20,294 primary unilateral total hip (48%) and knee (52%) arthroplasty cases at a tertiary health system were extracted from the institutional electronic medical record. Discharge location and the 9 preoperative variables required by the predictive model were collected. All cases were run through the model to generate risk scores for those patients, which were compared with the actual discharge locations to evaluate the cutoff originally proposed in the derivation paper. The proportion of correct classifications at this threshold was evaluated, as well as the sensitivity, specificity, positive and negative predictive values, number needed to screen, and area under the receiver operating characteristic curve (AUC), in order to determine the predictive accuracy of the model. RESULTS: A total of 3,147 (15.5%) of the patients who underwent primary, unilateral total hip or knee arthroplasty were discharged to rehabilitation or an SNF. Despite considerable differences between the present and original model derivation cohorts, predicted scores demonstrated very good accuracy (AUC, 0.734; 95% confidence interval, 0.725 to 0.744). The threshold simultaneously maximizing sensitivity and specificity was 0.1745 (sensitivity, 0.672; specificity, 0.679), essentially identical to the proposed cutoff of the original paper (0.178). The proportion of correct classifications was 0.679. Positive and negative predictive values (0.277 and 0.919, respectively) were substantially better than those of random selection based only on event prevalence (0.155 and 0.845), and the number needed to screen was 3.6 (random selection, 6.4). CONCLUSIONS: A previously published online predictive tool for discharge to rehabilitation or an SNF performed well under external validation, demonstrating a positive predictive value 79% higher and number needed to screen 56% lower than simple random selection. This tool consists of exclusively preoperative parameters that are easily collected. Based on a successful external validation, this tool merits consideration for clinical implementation because of its value for patient counseling, preoperative optimization, and discharge planning. LEVEL OF EVIDENCE: Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence.

Intraoperative Technology Use Improves Accuracy of Functional Safe Zone Targeting in Total Hip Arthroplasty.

BACKGROUND: Targets of acetabular inclination and anteversion have been suggested based on a patient's spinopelvic mobility. Current methods in total hip arthroplasty (THA) include manual instrumentation, computer-assisted navigation, and robotic-assisted surgery. This study aims to compare the accuracy of these 3 methods in targeting the functional safe zone. METHODS: This is a prospective multicenter study including a series of 251 consecutive primary posterior THA patients from April 2019 to January 2021. Preoperative lateral standing and sitting spinopelvic radiographs were obtained. Each patient was classified using the Hip-Spine Classification. A functional safe zone plan was determined. Surgeons used their preferred method (manual instrumentation, computer-assisted, or robotic-assisted). Postoperative anteversion and inclination was measured and compared to the preoperative plan. Mean differences between preoperative and postoperative values were calculated. Welch's t-test was used to assess significant between-group differences with P < .05 considered significant. RESULTS: Of the 249 patients, there were 63 manual instrumentation, 68 computer-assisted navigation, and 118 robotic-assisted surgery. Robotic-assisted surgery (rTHA) was significantly more accurate in targeting anteversion (1 ± 2) compared to manual instrumentation (mTHA; 7 ± 6, P < .001) and computer-assisted navigation (cTHA; 6 ± 6, P < .001). rTHA was also significantly more accurate in targeting inclination (1 ± 1) compared to mTHA (8 ± 7, P < .001) and cTHA (6 ± 7, P < .001). Although cTHA had greater accuracy in targeting both inclination and anteversion compared to mTHA, these differences were not statistically significant. CONCLUSION: Robotic-assisted surgery was more accurate than both computer-assisted navigation and manual instrumentation in targeting the functional safe zone in primary THA. Further research is needed to evaluate the effect of improved accuracy on dislocation rates.

The Impact of Patient Resilience on Discharge After Total Hip Arthroplasty.

BACKGROUND: Patients who undergo total hip arthroplasty (THA) require resilience to recover and resume daily functions. Increased resilience may be an important factor for achieving improved outcomes. The purpose of this study is to examine the impact of resilience on time to discharge and on early patient-reported outcomes following primary THA. METHODS: A retrospective review of patients who underwent primary THAs and completed the Brief Resilience Scale (BRS) was conducted from 2020 to 2021 at an urban, academic hospital. Patients were separated into 3 cohorts based on BRS score: low (1-2.99), normal (3-4.30), and high (4.31-5) resilience. Demographics, participation in same-day discharge (SDD) program, length of stay (LOS), and preoperative and 3-month postoperative scores on the Hip Disability and Osteoarthritis Outcome Score Joint Replacement (HOOS JR) were assessed. SDD patients were excluded from LOS analysis. RESULTS: A total of 393 patients were included. Compared to low resilience patients, odds of being enrolled in SDD program were 1.49 and 3.01 times higher (P = .01) and 3-month HOOS JR scores improved by 4.7% and 11.7% (P = .03) for normal and high resilience patients, respectively. As resilience increased from low to normal to high in non-SDD patients, LOS significantly decreased (53.27 ± 51.92 vs 38.70 ± 28.03 vs 25.64 ± 14.48 hours, respectively; P = .001). CONCLUSION: Increased resilience is positively associated with likelihood of SDD participation or decreased LOS. Increased resilience was associated with increased HOOS JR scores at 3 months, although this did not reach the minimal clinically important difference. The BRS may be a useful tool for predicting patients who can successfully participate in SDD or predicting LOS after primary THA.

Comparison of Operating Room Air Quality in Primary Versus Revision Total Knee Arthroplasty.

BACKGROUND: Airborne biologic particles (ABPs) can be measured intraoperatively to evaluate operating room (OR) sterility. Particulate matter (PM) up to 2.5 microns can contain microbial species which may increase infection risk. Our study examines the differences in air quality and ABP count in primary total knee arthroplasty (TKA) and revision TKA (rTKA). METHODS: We analyzed primary and rTKAs in a single OR at an academic institution from January 2020 to December 2020. Procedures from March 15, 2020, to May 4, 2020, were excluded to avoid COVID-related confounding. Temperature, humidity, and ABP count per minute were recorded with a particle counter intraoperatively and cross-referenced with surgical data from the electronic health records using procedure start and end times. Descriptive statistics were used to evaluate the differences in variables. P values were calculated using t-test and chi-square test. RESULTS: A total of 107 TKA cases were included: 79 (73.8%) primary TKAs and 28 (26.2%) rTKAs. Time spent in an OR was significantly higher for rTKAs (primary: 176 ± 46.7 minutes vs revision: 220 ± 47.1 minutes, P < .0001). Compared to primary TKAs, rTKAs had significant percent increases in ABP rates for particles measuring 0.3 µm (+70.4%, P < .001), 0.5 µm (+97.2%, P < .0001), 1.0 µm (+53.2%, P = .001), and 2.5 µm (+30.3%, P = .017) and for PM 2.5 (+108.3%, P < .001) and PM 5.0 (+105.6%, P < .001). CONCLUSION: rTKAs had significantly longer time spent in an OR and significant percent increases in ABP rates for particles measuring 0.3 µm, 0.5 µm, and 1.0 µm compared to primary TKAs. Measurements of PM 2.5 and 5.0 (which can contain large numbers of microbes) were also significantly greater in rTKAs. Further research is needed to determine whether the size and quantity of ABPs translate to higher infection rates after rTKA.

Impact of Preoperative Anemia Severity on Primary Total Hip Arthroplasty Outcomes.

BACKGROUND: Preoperative anemia (POA) is a significant predictor for adverse outcomes in primary total hip arthroplasty (THA). Current literature has studied POA stratified by severity. This study aims to find a threshold preoperative hemoglobin (Hb) value for increased risk of adverse outcomes in THA. METHODS: This is a retrospective analysis of primary THA patients with preoperative Hb values from 2014 to 2021 from an academic orthopedic specialty hospital. Demographics, surgical data, and postoperative outcomes were collected. Patients without preoperative Hb values within the electronic health record system or values acquired >30 days preoperatively were excluded. Patients were grouped based on POA severity using World Health Organization criteria. Secondary analysis using discrete preoperative Hb values was performed. P-values were calculated using analysis of variance/Kruskal-Wallis and chi-squared/Fisher's exact testing with P < .05 considered significant. RESULTS: A total of 1347 patients were included: 771 (57.2%) patients with POA and 576 (42.8%) with normal preoperative Hb. In the POA group, 292 (37.9%) were mild, 445 (57.7%) moderate, and 34 (4.4%) severe. Increased length of stay was seen in moderate (3.9 ± 4.3 vs 2.4 ± 2.1, P < .001) and severe (5.0 ± 3.4 vs 2.4 ± 2.1, P < .0001) groups compared to control. The severe group had higher 90-day readmission and revision rates compared to control. Analysis by discrete Hb values showed increased length of stay in Hb values <11 g/dL and a greater proportion of patients with Hb values <12 g/dL were discharged to skilled nursing facilities. CONCLUSION: Patients with preoperative Hb <12 g/dL should be assessed for other risk factors that may predispose them to postoperative complications. Further investigation is warranted to develop more robust perioperative management strategies for POA patients undergoing THA. LEVEL III EVIDENCE: Retrospective Cohort Study.

Conversion total hip arthroplasty for early failure following unstable intertrochanteric hip fracture: what can patients expect?

PURPOSE: To report surgical outcomes in patients treated with conversion total hip arthroplasty (CTHA) for early failure of cephalomedullary nails (CMNs). METHODS: A retrospective review was conducted of CTHA for treatment of failed CMN within 1 year of initial surgery for intertrochanteric (IT) hip fractures. The cohort was matched 1:5 to patients who underwent elective primary THA (PTHA). Patient demographics, mechanism of CMN failure, surgical outcomes, and complication rates were assessed. RESULTS: 22 patients met criteria with a mean time to failure of 145 days. Modes of failure included: lag screw cut-out with superior migration (9, 40.9%), or medialization (8, 36.4%), and aseptic nonunion with implant failure (2, 9.0%) and without implant failure (3, 13.6%). Fourteen of the patients (63.6%) had acetabular-sided damage secondary to lag screw penetration, all in the screw cut-out groups. Patient demographics were similar between cohorts. Compared to PTHA, CTHA patients had increased operative time, blood loss, LOS, and readmission rates. After IMN failure, the operative leg was shorter than the contralateral leg in all cases. CTHA restored leg lengths to < = 10 mm in 15 (68.1%) of patients, with an average leg length discrepancy after CTHA of 6.7 mm. CTHA patients had increased rates of overall surgical complications and medical complications, specifically anemia (all p < 0.01). Tranexamic acid was used less often in the CTHA group (p < 0.01). Rate of periprosthetic joint infection (PJI), dislocation, and revision were all higher in the CTHA, though did not reach statistical significance. CONCLUSION: The majority (77.3%) of CMN implant failure for nonunion within 1 year was due to screw cut-out. CTHA is a salvage option for early failed IT hip fracture repair, but expected surgical outcomes are more similar to revision THA than primary THA, with increased risk of readmission, longer surgery and LOS, increased blood loss, and higher complication rates. LEVEL OF EVIDENCE: III, Retrospective comparative study.