Functional Acetabular Component Positioning During Direct Anterior Approach Hip Arthroplasty Using a Novel Three-Dimensional Virtual Mesh Imaging System With Fluoroscopy.

BACKGROUND: Optimal position of total hip arthroplasty (THA) components is critical for joint mechanics and stability. Acetabular component positioning during supine surgery in direct anterior approach (DAA) THA may be different in the standing position postoperatively, which traditional fluoroscopy is unable to predict. A novel 3-dimensional (3D) image analysis technology (IAT) that uses artificial intelligence to measure the tilt and rotation of the pelvis has enabled prediction of component positioning from supine to standing. The purpose of this study was to compare intraoperative fluoroscopy, non-3D-IAT, and 3D-IAT with postoperative standing radiographs to assess the accuracy of component positioning. METHODS: From 2022 to 2023, 30 consecutive patients (86.6% women, mean age 59 [range, 55 to 67]) undergoing primary DAA THA with the use of the 3D-IAT were identified. A separate cohort of 148 patients from 2020 to 2021 (85% women, mean age 65 [range, 55 to 69]) who underwent DAA THA with non-3D-IAT was used for comparison. Leg length discrepancy (LLD), cup anteversion, and inclination were manually measured on intraoperative fluoroscopic images and digitally measured using IAT. Follow-up evaluation occurred at 1 month with standing pelvis radiographs measured using Ein Bild Röntgen Analyze-Cup software. Measurements were compared via Wilcoxon signed rank tests where P ≤ .05 indicates significantly different measurements. RESULTS: Median LLD, inclination, and anteversion measurements via non-3D-IAT and fluoroscopy were significantly different compared to postoperative standing radiographs (P < .001). The 3D-IAT more accurately predicted LLD, abduction, and anteversion, with values not significantly different from postoperative standing measurements (P = .23, P = .93, and P = .36, respectively). CONCLUSIONS: The use of the 3D-IAT during DAA THA allowed for the more accurate prediction of acetabular component position in the standing position postoperatively.

Novel Use of an Accelerometer to Assess Load Asymmetry Over Time After Hip Resurfacing Arthroplasty.

BACKGROUND: There is limited knowledge regarding usage of wearable technology to guide return to sport after hip resurfacing arthroplasty (HRA). This study evaluated the use of accelerometers to identify when symmetry is restored between operative and nonoperative limbs. METHODS: A total of 26 primary HRA patients performed 5 validated physical tests before, 3 and 6 months after HRA: broad jump, double-leg vertical jump (DLVJ), hop test, lateral single-leg jump (LSLJ), and vertical single-leg jump. Impact load and average intensity data (g-force units) were collected using accelerometers. Strength data (pounds [lbs.]) for internal and external rotation were collected with a dynamometer. Univariate and correlation analyses analyzed interlimb asymmetries. RESULTS: At preoperation, there were significant impact load asymmetries for DLVJ (P = .008), hop test (P = .021), and LSLJ (P = .003) and intensity asymmetry for DLVJ (P = .010) and LSLJ (P = .003). At 3 months, there was impact load asymmetry for DLVJ (P = .005) and LSLJ (P = .005) and intensity asymmetry for broad jump (P = .020), hop test (P = .042), and LSLJ (P = .005). There were significant strength asymmetries at preoperation and 3 months postoperation for internal (P = .013) and external rotation (P = .037). All significant asymmetries indicated the nonoperative leg had greater output. No significant asymmetries were found for any exercises at 6 months postoperation. An increase in Harris Hip Score was significantly associated with a decrease in impact asymmetry (rs = -0.269, P = .006). CONCLUSION: Impact loads and strength reach interlimb symmetry at 6 months post-HRA. Wearable accelerometers provide useful metrics to distinguish limb asymmetries for recovery monitoring.

Preoperative ferritin and hemoglobin levels are lower in patients with a history of COVID-19 but blood loss and transfusion requirements are not increased.

INTRODUCTION: A history of COVID-19 (Coronavirus Disease 2019), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may have an impact on hemoglobin and ferritin levels predisposing patients to increased blood transfusion requirements following total joint arthroplasty (TJA). The current study compares ferritin levels, hemoglobin levels, and transfusion rates between SARS-CoV-2 IgG positive and SARS-CoV-2 IgG negative TJA patients. MATERIALS AND METHODS: Preoperative ferritin levels, pre- and postoperative hemoglobin levels, postoperative change in hemoglobin, and transfusion rates of 385 consecutive SARS-CoV-2 IgG positive patients undergoing TJA were compared to those of 5156 consecutive SARS-CoV-2 IgG negative patients undergoing TJA. RESULTS: Preoperative hemoglobin levels were significantly lower in SARS-CoV-2 IgG positive patients [13.3 g/dL (range 8.9-17.7 g/dL)] compared to 13.5 g/dl (7.3-18.3 g/dL; p value 0.03). Ferritin levels were significantly lower in SARS-CoV-2 IgG positive patients (mean of 106.1 ng/ml (2.1-871.3.3 ng/ml) vs. 123.7 ng/ml (1.4-1985 ng/ml) (p value 0.02)). Hemoglobin on postoperative day (POD) one, after four-six weeks, and transfusion rates did not differ between the two groups. CONCLUSION: Although preoperative hemoglobin and ferritin levels are lower in SARS-CoV2 IgG positive patients, there was no difference in hemoglobin on POD one, recovery of hemoglobin levels at four-six weeks postoperatively, and transfusion rates after surgery. Routine ferritin testing prior to TJA is not recommended in SARS-CoV-2 IgG positive patients.

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.

Robotic Assistance for Posterior Approach Total Hip Arthroplasty Is Associated With Lower Risk of Revision for Dislocation When Compared to Manual Techniques.

BACKGROUND: Robotic-assistance total hip arthroplasty (RA-THA) and computer navigation THA (CN-THA) have been shown to improve accuracy of component positioning compared to manual techniques; however, controversy exists regarding clinical benefit. Moreover, these technologies may expose patients to risks. The purpose of this study is to compare rates of intraoperative fracture and complications requiring reoperation within 1 year for posterior approach RA-THA, CN-THA, and THA with no technology (Manual-THA). METHODS: In total, 13,802 primary, unilateral, elective, posterior approach THAs (1770 RA-THAs, 3155 CN-THAs, and 8877 Manual-THAs) were performed at a single institution between 2016 and 2020. Intraoperative fractures and reoperations within 1 year of the index procedure were identified. Cohorts were balanced using inverse probability of treatment weight based on age, gender, body mass index, femoral cementation, history of spine fusion, and Charlson Comorbidity Index. Logistic regression was performed to create odds ratios for complications. Additional regression analysis for dislocation was performed, adjusting for dual mobility and femoral head size. RESULTS: There were no differences in intraoperative fracture and postoperative complication rates between the groups (P = .521). RA-THA had a 0.3 odds ratio (95% confidence interval 0.1-0.9, P = .046) compared to Manual-THA for reoperation due to dislocation. CN-THA had an odds ratio of 3.0 for reoperation due to dislocation (95% confidence interval 0.8-11.3, P = .114) compared to RA-THA. The remaining complication odds ratios, including those for infection, loosening, dehiscence, and "other" were similar between the groups. CONCLUSION: RA-THA is associated with lower risk of revision for dislocation within 1 year of index surgery, when compared to Manual-THA performed through the posterior approach.

Favorable Radiographic and Early Postoperative Results with the Inguinal Crease Direct Anterior Total Hip Arthroplasty.

We report the results, scar appearance, and patient satisfaction of a direct anterior approach total hip arthroplasty performed through an oblique inguinal incision. Patients were separated into direct anterior THA (n = 29) or an oblique inguinal incision anterior approach (n = 41). Clinical and radiographic data was compared, scar appearance was assessed by the Vancouver Scar Scale (VSS), and satisfaction was assessed by a simple questionnaire. Harris Hip Scores significantly improved in each group (1.8×10-8) and improved similarly between groups (p ≥ 0.35). The VSS score was lower in the inguinal incision versus the standard incision group (0.68 [range 0-3] vs. 1.56 [range 0-4], p = 0.015). Scar satisfaction was higher in the inguinal incision group with 87% compared to only 32% in the standard approach. The inguinal incision approach was safe, offered similar postoperative results, and resulted in improved patient scar satisfaction compared to the standard anterior approach by using an incision that more closely resembled normal anatomy. (Journal of Surgical Orthopaedic Advances 31(1):056-060, 2022).

Reduction in hospital length of stay and increased utilization of telemedicine during the "return-to-normal" period of the COVID-19 pandemic does not adversely influence early clinical outcomes in patients undergoing total hip replacement: a case-control study.

BACKGROUND AND PURPOSE: Elective total hip replacement (THR) was halted in our institution during the COVID-19 surge in March 2020. Afterwards, elective THR volume increased with emphasis on fast-track protocols, early discharge, and post-discharge virtual care. We compare early outcomes during this "return-to-normal period" with those of a matched pre-pandemic cohort. PATIENTS AND METHODS: We identified 757 patients undergoing THR from June to August 2020, who were matched 1:1 with a control cohort from June to August 2019. Length of stay (LOS) for the study cohort was lower than the control cohort (31 vs. 45 hours; p < 0.001). The time to first postoperative physical therapy (PT) was shorter in the study cohort (370 vs. 425 minutes; p < 0.001). More patients were discharged home in the study cohort (99% vs. 94%; p < 0.001). Study patients utilized telehealth office and rehabilitation services 14 times more frequently (39% vs. 2.8%; p < 0.001). Outcomes included post-discharge 90-day unscheduled office visits, emergency room (ER) visits, complications, readmissions, and PROMs (HOOS JR, and VR-12 mental/physical). Mann-Whitney U and chi-square tests were used for group comparisons. RESULTS: Rates of 90-day unscheduled outpatient visits (5.0% vs. 7.3%), ER visits (5.0% vs. 4.8%), hospital readmissions (4.0% vs. 2.8%), complications (0.04% vs. 0.03%), and 3-month PROMs were similar between cohorts. There was no 90-day mortality. INTERPRETATION: A reduction in LOS and increased telehealth use for office and rehabilitation visits did not adversely influence 90-day clinical outcomes and PROMs. Our findings lend further support for the utilization of fast-track arthroplasty with augmentation of postoperative care delivery using telemedicine.

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.

Is There an Association Between Negative Patient-Experience Comments and Perioperative Outcomes After Primary Total Hip Arthroplasty?

BACKGROUND: Multiple stakeholders are interested in improving patient experience after primary total hip arthroplasty due to shifts toward patient-centered care. Patient free-text narratives are a potentially valuable but largely unexplored source of data. METHODS: The records of 383 patients who underwent primary total hip arthroplasty between August 2016 and August 2019 were combined with vendor-supplied patient satisfaction data, which included patient free-text comments and the Press Ganey satisfaction survey. A total of 1295 patient comments were analyzed for sentiment, and negative comments were categorized into nine themes. Postoperative outcomes, patient-reported outcome measures, and traditional measures of satisfaction were compared between patients who provided a negative comment vs those who did not. Multivariable regression was used to determine perioperative variables associated with providing a negative comment. RESULTS: Of the 1295 patient comments: 54% were positive, 24% were negative, 10% were mixed, and 12% were neutral. Top two themes of negative comments were room condition (25%) and inefficient communication (23%). There were no differences in studied outcomes (eg. peak pain intensity, length of stay, or improvements in hip injury and osteoarthritis outcome scores Jr. and pain visual analog scale scores at 6-week follow-up) between those who provided negative comments vs those who did not (P > .05). However, patients who made negative comments were less likely to recommend their hospital care to peers (P < .001). Finally, patients who had >2 allergies (P = .024) were more likely to provide negative comments. CONCLUSION: The present study demonstrates that patient satisfaction appears not to be a reliable sole proxy for traditional objective outcome measures of pain relief and functional improvement.

Modern Internet Search Analytics and Total Joint Arthroplasty: What Are Patients Asking and Reading Online?

BACKGROUND: Patients considering total joint arthroplasty often search for information online regarding surgery; however, little is known about the specific topics that patients search for and the nature of the information provided. Google compiles frequently asked questions associated with a search term using machine learning and natural language processing. Links to individual websites are provided to answer each question. Analysis of this data may help improve understanding of patient concerns and inform more effective counseling. METHODS: Search terms were entered into Google for total hip and total knee arthroplasty. Frequently asked questions and associated websites were extracted to a database using customized software. Questions were categorized by topic; websites were categorized by type. JAMA Benchmark Criteria were used to assess website quality. Pearson's chi-squared and Student's t-tests were performed as appropriate. RESULTS: A total of 620 questions (305 total knee arthroplasties, 315 total hip arthroplasties) were extracted with 602 associated websites. The most popular question topics were Specific Activities (23.5%), Indications/Management (15.6%), and Restrictions (13.4%). Questions related to Pain were more common in the TKA group (23.0% vs 2.5%, P < .001) compared to THA. The most common website types were Academic (31.1%), Commercial (29.2%), and Social Media (17.1%). JAMA scores (0-4) were highest for Government websites (mean 3.92, P = .005). CONCLUSION: The most frequently asked questions on Google related to total joint arthroplasty are related to arthritis management, rehabilitation, and ability to perform specific tasks. A sizable proportion of health information provided originate from non-academic, non-government sources (64.4%), with 17.1% from social media websites.

Natural Language Processing of Patient-Experience Comments After Primary Total Knee Arthroplasty.

BACKGROUND: There is interest in improving patient experience after total knee arthroplasty (TKA) due to recent shifts toward value-based medicine. Patient narratives are a valuable but unexplored source of information. METHODS: Records of 319 patients who had undergone primary TKA between August 2016 and August 2019 were linked with vendor-supplied patient satisfaction data, which included patient comments and the Press Ganey satisfaction survey. Using machine-learning-based natural language processing, 1048 patient comments were analyzed for sentiment and classified into themes. Postoperative outcomes, patient-reported outcome measures, and traditional measures of satisfaction were compared between patients who provided a negative comment vs those who did not (positive, neutral, mixed grouped together). Multivariable regression was used to determine perioperative variables associated with providing a negative comment. RESULTS: Of the 1048 patient comments, 25% were negative, 58% were positive, 8% were mixed, and 9% were neutral. Top 2 themes of negative comments were room condition (25%) and inefficient communication (23%). There were no differences in most of the studied outcomes (eg, peak pain intensity, length of stay, or Knee Injury and Osteoarthritis Outcome Score Junior and pain scores at 6-week follow-up) between the 2 cohorts (P > .05). However, patients who made negative comments were less likely to highly recommend their hospital care to peers (P < .001). Finally, patients who had higher American Society of Anesthesiologists Score and those who received a scopolamine patch were more likely to provide negative comments (P < .05). CONCLUSION: Although the current study showed that patient satisfaction might not be a proxy for traditional objective perioperative outcomes, efforts to improve the nontechnical aspects of medicine are still crucial in providing patient-centered care.

Industry Payments and Their Association With Academic Influence in Total Joint Arthroplasty.

BACKGROUND: The relationship between industry payments and academic influence, as measured by the Hirsch index (h-index) and number of publications, among adult reconstruction surgeons is not well characterized. The aims of the present study are to determine the relationship between an adult reconstruction surgeons' academic influence and their relevant industry payments and National Institutes of Health (NIH) funding. METHODS: Adult reconstruction surgeons were identified through the websites for the orthopedic surgery residency programs in the United States during the 2019-2020 academic year. Academic influence was approximated by each physician's h-index and total number of publications. Industry payment data were obtained through the Open Payments Database, and NIH funding was determined through the NIH website. Mann-Whitney U testing and Spearman correlations were performed to examine relevant associations. RESULTS: Surgeons who received industry research payments had a higher mean h-index (16.1 vs 10.2, P < .001) and mean number of publications (79.1 vs 35.9, P < .001) than physicians who received no industry research payments. Surgeons receiving NIH funding had a higher mean h-index (48.1 vs 10.4, P < .001) and mean number of publications (294.5 vs 36.8, P < .001) than surgeons who did not receive NIH funding. There was no association between the average h-index (P = .668) and number of publications (P = .387) among adult reconstruction surgeons receiving industry nonresearch funding. CONCLUSION: h-index and total publications do not seem to be associated with industry nonresearch payments in the field of total joint arthroplasty. Altogether, these data suggest that industry bias may not play a strong role in total joint arthroplasty.

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.

COVID-19-Related Internet Search Patterns Among People in the United States: Exploratory Analysis.

BACKGROUND: The internet is a well-known source of information that patients use to better inform their opinions and to guide their conversations with physicians during clinic visits. The novelty of the recent COVID-19 outbreak has led patients to turn more frequently to the internet to gather more information and to alleviate their concerns about the virus. OBJECTIVE: The aims of the study were to (1) determine the most commonly searched phrases related to COVID-19 in the United States and (2) identify the sources of information for these web searches. METHODS: Search terms related to COVID-19 were entered into Google. Questions and websites from Google web search were extracted to a database using customized software. Each question was categorized into one of 6 topics: clinical signs and symptoms, treatment, transmission, cleaning methods, activity modification, and policy. Additionally, the websites were categorized according to source: World Health Organization (WHO), Centers for Disease Control and Prevention (CDC), non-CDC government, academic, news, and other media. RESULTS: In total, 200 questions and websites were extracted. The most common question topic was transmission (n=63, 31.5%), followed by clinical signs and symptoms (n=54, 27.0%) and activity modification (n=31, 15.5%). Notably, the clinical signs and symptoms category captured questions about myths associated with the disease, such as whether consuming alcohol stops the coronavirus. The most common websites provided were maintained by the CDC, the WHO, and academic medical organizations. Collectively, these three sources accounted for 84.0% (n=168) of the websites in our sample. CONCLUSIONS: In the United States, the most commonly searched topics related to COVID-19 were transmission, clinical signs and symptoms, and activity modification. Reassuringly, a sizable majority of internet sources provided were from major health organizations or from academic medical institutions.

How Useful Is Magnetic Resonance Imaging in Evaluating Adverse Local Tissue Reaction?

Biologic failures of hip arthroplasty have emerged as an increasing threat to the longevity of the prosthesis. While wear of modern-day bearings has been greatly reduced with the advent of cross-linked polyethylene, local reaction to metal particles either from the bearing itself or to any of the modular tapers appears to be on the rise. Monitoring of these reactions by the use of plain radiographs or serum markers appears to be insufficient to gauge the gravity of the response. Over the past decade, the use of magnetic resonance imaging (MRI) techniques has emerged as the superior noninvasive instrument to assess the extent of soft tissue reaction around hip implants. The use of MRI around implants was initially challenging due to the presence of relatively high ferrous metals especially cobalt which causes local distortion of the magnetic fields. Novel changes in pulse sequencing have greatly improved the sensitivity and specificity of MRI so that at this time, MR is the most predictive diagnostic tool in evaluating the extent of tissue destruction. We feel strongly that modern MRI techniques are the most important tool in the workup of the patient suspected of having an adverse tissue reaction after hip arthroplasty.

Reasons and Risk Factors for 30-Day Readmission After Outpatient Total Knee Arthroplasty: A Review of 3015 Cases.

BACKGROUND: A higher volume of primary total knee arthroplasty (TKA) is starting to be performed in the outpatient setting. However, data on appropriate patient selection in the current literature are scarce. METHODS: Patients who underwent primary TKA were identified in the 2012-2017 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. Reasons for and timing of readmission were identified. Risk factors for and effect of overnight hospital stay on 30-day readmission were evaluated. RESULTS: A total of 3015 outpatient TKA patients were identified. The incidence of 30-day readmission was 2.59% (95% confidence interval [CI] 2.02-3.15). The majority of readmissions were nonsurgical site related (64%), which included thromboembolic and gastrointestinal complications. Risk factors for 30-day readmission include dependent functional status prior to surgery (relative risk [RR] 6.4, 95% CI 1.91-21.67, P = .003), hypertension (RR 2.5, 95% CI 1.47-4.25, P = .001), chronic obstructive pulmonary disease (RR 2.4, 95% CI 1.01-5.62, P = .047), and operative time ≥91 minutes (≥70th percentile) (RR 1.9, 95% CI 1.17-2.98, P = .008). For patients who had some of these risk factors, their rate of 30-day readmission was significantly reduced if they had stayed at least 1 night at the hospital. CONCLUSION: Overall, the rate of 30-day readmission after outpatient TKA was low. Patients who are at high risk for 30-day readmission after outpatient TKA include those with dependent functional status, hypertension, chronic obstructive pulmonary disease, and prolonged operative time. These patients had reduced readmissions after overnight admission and seem to benefit from an inpatient hospital stay.

Prospective Evaluation of the Posterior Tissue Envelope and Anterior Capsule After Anterior Total Hip Arthroplasty.

BACKGROUND: Femoral exposure for direct anterior approach (DAA) total hip arthroplasty (THA) invariably requires posterior soft tissue releases. Released posterior structures cannot be repaired. The purpose of this study is to describe the frequency and anatomic consequences of DAA THA posterior soft tissue releases and to compare the appearance of the anterior capsule between a group of patients who had capsulotomy and repair versus capsulectomy. METHODS: Thirty-two DAA THA patients underwent metal artifact reduction sequence magnetic resonance imaging at discharge and 1-year follow-up. Seventeen had underwent capsulotomy and repair and 15 capsulectomy. A radiologist blinded to intraoperative data scored each metal artifact reduction sequence magnetic resonance imaging. Anterior capsular integrity, status of the piriformis and conjoint tendons, and muscle atrophy were graded. Descriptive statistics were performed to analyze results. RESULTS: Immediately postoperatively, 75% of piriformis tendons were intact and 38% of conjoined tendons were intact. At 1 year, 97% had an intact piriformis and conjoined tendon, although many were in continuity through scar with the capsule. The posterior capsule directly contacted bone in all patients. At 1 year, none of the patients who underwent capsulotomy with repair had persistent anterior capsule defects, while 27% in the capsulectomy group had persistent defects. CONCLUSION: Posterior capsule and conjoined tendon releases were commonly performed during DAA THA, yet continuity with bone was frequently achieved at 1 year. In this study, capsulotomy with repair resulted in no anterior capsular defects when compared with capsulectomy. These results may support improved THA stability observed after DAA with capsular repair despite posterior soft tissue releases. LEVEL OF EVIDENCE: Level III, prospective cohort study.

Addition of Infiltration Between the Popliteal Artery and the Capsule of the Posterior Knee and Adductor Canal Block to Periarticular Injection Enhances Postoperative Pain Control in Total Knee Arthroplasty: A Randomized Controlled Trial.

BACKGROUND: Periarticular injections (PAIs) are becoming a staple component of multimodal joint pathways. Motor-sparing peripheral nerve blocks, such as the infiltration between the popliteal artery and capsule of the posterior knee (IPACK) and the adductor canal block (ACB), may augment PAI in multimodal analgesic pathways for knee arthroplasty, but supporting literature remains rare. We hypothesized that the addition of ACB and IPACK to PAI would lower pain on ambulation on postoperative day (POD) 1 compared to PAI alone. METHODS: This triple-blinded randomized controlled trial included 86 patients undergoing unilateral total knee arthroplasty. Patients either received (1) a PAI (control group, n = 43) or (2) an IPACK with an ACB and modified PAI (intervention group, n = 43). The primary outcome was pain on ambulation on POD 1. Secondary outcomes included numeric rating scale (NRS) pain scores, patient satisfaction, and opioid consumption. RESULTS: The intervention group reported significantly lower NRS pain scores on ambulation than the control group on POD 1 (difference in means [95% confidence interval], -3.3 [-4.0 to -2.7]; P < .001). In addition, NRS pain scores on ambulation on POD 0 (-3.5 [-4.3 to -2.7]; P < .001) and POD 2 (-1.0 [-1.9 to -0.1]; P = .033) were significantly lower. Patients in the intervention group were more satisfied, had less opioid consumption (P = .005, postanesthesia care unit, P = .028, POD 0), less intravenous opioids (P < .001), and reduced need for intravenous patient-controlled analgesia (P = .037). CONCLUSIONS: The addition of IPACK and ACB to PAI significantly improves analgesia and reduces opioid consumption after total knee arthroplasty compared to PAI alone. This study strongly supports IPACK and ACB use within a multimodal analgesic pathway.

Conversion of Hip Resurfacing With Retention of Monoblock Acetabular Shell Using Dual-Mobility Components.

BACKGROUND: Retention of the acetabular component is an option during conversion from hip resurfacing arthroplasty (HRA) to total hip arthroplasty (THA). The purpose of this study was to compare clinical outcomes of conversion of the femoral resurfacing component with retained acetabular components (RAC) and use of dual-mobility femoral heads to outcomes of patients treated with both component (BC) revisions. METHODS: A retrospective review was performed of the clinical outcomes of HRA to THA conversions performed at a single institution between 2008 and 2017. RESULTS: Seventy-one conversions were included (27 RAC and 44 BC). Average age at time of conversion was 54.4 years (range, 30-68 years). Median time to conversion was 5.14 (2.77-7.41) years and median follow-up post-conversion was 1.7 (0.33-4.0) years. There were no significant differences in indications for conversion between the 2 groups with the majority performed for complications related to elevated metal ions and aseptic loosening. Harris Hip Scores improved from pre-conversion to post-conversion in both cohorts (P < .01). There were no significant differences in pre-conversion and post-conversion metal ion levels between the RAC and BC groups. Serum metal ion levels decreased significantly in both cohorts (P < .01). There were 6 additional revisions in the cohort (4 in BC, 2 in RAC) at a median 2.94 (1.99-3.85) years post-conversion. Two RAC patients had intraprosthetic dislocations with extensive polyethylene wear requiring acetabular revision at median 3.92 (3.85-3.98) years post-conversion. Overall, there were a higher number of complications in the BC group related to acetabular fracture, failure of osseointegration, and periprosthetic joint infection; however, this did not reach statistical significance (P = .27). CONCLUSION: Salvage of an appropriately positioned, well-fixed HRA acetabular component is a reasonable option in the setting of conversion to THA using dual-mobility components. This technique avoids the morbidity of acetabular revision and was associated with a decrease in metal ion levels and improvements in short-term functional outcomes comparable to a BC revision.

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.