Robotic-assisted total knee arthroplasty is associated with the use of thinner polyethylene liners compared to navigation-guided and manual techniques.

PURPOSE: The purpose of this study was to examine the effects of intraoperative technology use on the rate of using polyethylene liners 15 mm or greater during primary total knee arthroplasty (TKA). METHODS: There were 103,295 implants from 16,386 primary unilateral TKAs performed on 14,253 patients at a single institution between 1 January 2018, and 30 June 2022, included in the current study. Robotic assistance and navigation guidance were used in 1274 (8%) and 8345 (51%) procedures, respectively. The remaining 6767 TKAs (41%) were performed manually. Polyethylene liners were manually identified and further subcategorised by implant thickness. Patients who underwent robotic-assisted TKA were younger (p < 0.001) and more likely to be male (p < 0.001) compared to patients who underwent navigation-guided or manual TKAs. RESULTS: Average polyethylene liner thickness was similar between groups (10.5 ± 1.5 mm for robotic-assisted TKAs, 10.9 ± 1.8 mm for navigation-guided TKAs and 10.8 ± 1.8 mm for manual TKAs). The proportions of polyethylene liners 15 mm or greater used were 4.9%, 3.8% and 1.9% for navigation-guided, manual and robotic-assisted procedures, respectively (p < 0.001). Multivariate regression analyses demonstrated that navigation-guided (odds ratio [OR]: 2.6, 95% confidence Interval [CI]: [1.75-4.07], p < 0.001) and manual (OR: 2.0, 95% CI: [1.34-3.20], p = 0.001) procedures were associated with an increased use of polyethylene liners 15 mm or greater. CONCLUSION: Robotic-assisted TKA was associated with a lower proportion of polyethylene liners 15 mm or greater used compared to navigation-guided and manual TKA. These findings suggest that robotic assistance can reduce human error via a more precise cutting system, limit over-resection of the tibia and flexion-extension gap mismatch and ultimately allow for more appropriately sized implants. LEVEL OF EVIDENCE: Level III, retrospective cohort study.

High degree of alignment precision associated with total knee arthroplasty performed using a surgical robot or handheld navigation.

PURPOSE: The purpose of this study was to compare the precision of bony resections during total knee arthroplasty (TKA) performed using different computer-assisted technologies. METHODS: Patients who underwent a primary TKA using an imageless accelerometer-based handheld navigation system (KneeAlign2®, OrthAlign Inc.) or computed tomography-based large-console surgical robot (Mako®, Stryker Corp.) from 2017 to 2020 were retrospectively reviewed. Templated alignment targets and demographic data were collected. Coronal plane alignment of the femoral and tibial components and tibial slope were measured on postoperative radiographs. Patients with excessive flexion or rotation preventing accurate measurement were excluded. RESULTS: A total of 240 patients who underwent TKA using either a handheld (n = 120) or robotic (n = 120) system were included. There were no statistically significant differences in age, sex, and BMI between groups. A small but statistically significant difference in the precision of the distal femoral resection was observed between the handheld and robotic cohorts (1.5° vs. 1.1° difference between templated and measured alignments, p = 0.024), though this is likely clinically insignificant. There were no significant differences in the precision of the tibial resection between the handheld and robotic groups (coronal plane 0.9° vs. 1.0°, n.s.; sagittal plane 1.2° vs. 1.1°, n.s.). There were no significant differences in the rate of overall precision between cohorts (n.s.). CONCLUSIONS: A high degree of component alignment precision was observed for both imageless handheld navigation and CT-based robotic cohorts. Surgeons considering options for computer-assisted TKA should take other important factors, including surgical principles, templating software, ligament balancing, intraoperative adjustability, equipment logistics, and cost, into account. LEVEL OF EVIDENCE: III.

Reasons and Risk Factors for Failed Same-Day Discharge After Primary Total Knee Arthroplasty.

BACKGROUND: As ambulatory total knee arthroplasty (TKA) becomes increasingly common, unplanned admission after surgery presents a challenge for the health care system. Studies evaluating the reasons and risk factors for this occurrence are limited. We sought to evaluate the reasons for unplanned admission after surgery and identify risk factors associated with this occurrence. METHODS: Patients registered in an institutional ambulatory joint arthroplasty program who underwent a TKA from 2017-2020 were retrospectively reviewed. The criteria for enrollment include candidates for unilateral TKA between the ages of 18 and 70 years, with a body mass index (BMI) of less than 35, and appropriate social and material support at home. Patients who had certain comorbidities including coronary artery disease, valvular heart disease, and opioid dependence were not eligible. A total of 274 patients who underwent TKA with planned same-day discharge (SDD) were identified in the medical record and reviewed. In this cohort, 140 patients (51.1%) were discharged on the day of surgery and 134 patients (48.9%) required a minimum 1-night admission. Demographics, comorbidities, and perioperative data were collected. Factors associated with failed SDD were identified using multivariate logistic regression. RESULTS: The most common reasons for failed SDD were failure to meet ambulation goals (25%) and logistical issues related to a late-day case (19%). Risk factors for failed SDD include general anesthesia (odds ratio (OR) 12.60, P = .047), procedure start time after 11:00 am (OR 5.16, P < .001), highest postoperative pain score >8 (visual analogue scale, OR 5.78, P = .001). Willingness to accept a higher pain threshold before discharge (visual analogue scale 4 to 10) was associated with successful SDD (OR 3.0, P < .001). Age and American Society of Anesthesiologists (ASA) classification were not associated with failed SDD. CONCLUSIONS: The most common reasons for failed SDD were related to logistical issues and postoperative mobilization. Risk factors for failed SDD involve case timing and pain control. Modifiable perioperative factors may play an important role in successful SDD after TKA.

Genetic Risk Factors for End-Stage Hip Osteoarthritis Treated With Total Hip Arthroplasty: A Genome-wide Association Study.

BACKGROUND: Although a genetic component to hip osteoarthritis (OA) has been described, focused evaluation of the genetic components of end-stage disease is limited. We present a genomewide association study for patients undergoing total hip arthroplasty (THA) to characterize the genetic risk factors associated with end-stage hip osteoarthritis (ESHO), defined as utilization of the procedure. METHODS: Patients who underwent primary THA for hip OA were identified in a national patient data repository using administrative codes. Fifteen thousand three hundred and fifty-five patients with ESHO and 374,193 control patients were identified. Whole genome regression of genotypic data for patients who underwent primary THA for hip OA corrected for age, sex, and body mass index (BMI) was performed. Multivariate logistic regression models were used to evaluate the composite genetic risk from the identified genetic variants. RESULTS: There were 13 significant genes identified. Composite genetic factors resulted in an odds ratio 1.04 for ESHO (P < .001). The effect of genetics was lower than that of age (Odds Ratio (OR): 2.38; P < .001) and BMI (1.81; P < .001). CONCLUSION: Multiple genetic variants, including 5 novel loci, were associated with end-stage hip OA treated with primary THA. Age and BMI were associated with greater odds of developing end-stage disease when compared to genetic factors.

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.

Predicting Total Knee Arthroplasty Outpatient Discharge: Surgeons versus Insurance Companies.

BACKGROUND: Insurance companies are increasingly making unilateral determinations of admission status for primary total knee arthroplasty (TKA). These determinations may differ from those based on surgeon-derived criteria for outpatient knee replacement. The goal of this study is to determine if insurance company determinations of outpatient status are as reliable as surgeon-derived criteria in predicting outpatient discharge after TKA. METHODS: We retrospectively reviewed 709 patients who were preoperatively authorized for outpatient TKA. Patients were stratified into 2 groups: "outpatient per surgeon" (appropriate for outpatient surgery per institutional protocols) or "outpatient per insurance" (appropriate for inpatient surgery per institutional protocols but denied inpatient status by insurance). The primary endpoint of this study was the conversion rate of outpatient to inpatient stay. Univariate logistic regression was performed to compare the odds of conversion to inpatient stay between outpatient per surgeon and outpatient per insurance procedures and other covariates. RESULTS: The cohort included 434 outpatient per insurance (61.2%) and 275 outpatient per surgeon (38.8%) patients. Surgeons accurately predicted outpatients' discharge 92.0% of the time, while insurance companies did so 81.3% of time (P < .001). Outpatient per insurance procedures (odds ratio [OR] 2.20, P = .003) and body mass index >35 kg/m2 (OR 1.82, P = .026) had higher odds of being converted to inpatient. Males had higher odds (OR 1.52, P < .001) of being discharged as outpatient. CONCLUSION: Determining inpatient versus outpatient status is a complex decision involving both clinical and social factors. Surgeons accurately predicted outpatient discharge 92% of the time. Moreover, outpatient per insurance procedures were twice as likely to be converted to inpatient status. Therefore, insurance companies should leave deciding admission status up to both the patient and surgeon.

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.

Analysis of Hip and Knee Reconstruction Questions on the Orthopedic In-Training Examination.

BACKGROUND: It is vital for orthopedic residents and residency programs to have a current understanding of the materials and resources utilized on the Orthopedic In-Training Examination (OITE) to tailor resident educational curricula accordingly. This study presents an updated analysis of the hip and knee section of the OITE. METHODS: All OITE questions related to hip and knee reconstruction over six examinations between 2014 and 2019 were analyzed for topic, subtopic, taxonomy, imaging modalities, resident performance, and references. RESULTS: There were 166 hip and knee reconstruction questions of 1600 OITE questions (10.4%) over a six-year period. The most commonly tested topics include mechanical properties of total knee and hip implants (10.8%), instability after THA (10.8%), periprosthetic fracture (10.2%), and prosthetic joint infection (10.2%). A total of 362 references were cited from 68 different sources. The most common sources were JOA, JBJS, JAAOS, and CORR, which were collectively responsible for 68% of all citations. There was an average publication lag of 7.1 years, with 75% of all citations falling within 10 years of the question date. Compared with a prior analysis from 2005 and 2009, there were significantly more complex multistep questions regarding treatment and fewer one-step knowledge recall questions (P = .003). Similarly, recent tests had significantly more questions involving interpretation of radiographs (55%, P < .001) and advanced imaging (9.6%, P < .001), compared with a decade ago. CONCLUSIONS: The OITE continues to evolve over time, incorporating recent literature and topics. The current analysis identifies high-yield topics and resources that can guide resident preparation for the OITE hip and knee section.

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.

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.

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.

Open Surgical Release of Posttraumatic Elbow Contracture in Children and Adolescents.

BACKGROUND: Posttraumatic elbow contractures in children and adolescents are challenging to manage, and studies investigating surgical treatment are limited by the rarity of this condition. Small case series have shown variable gains in immediate and long-term elbow arc of motion after open surgical release. We reviewed our experience with open surgical release of posttraumatic elbow contracture in patients <21 years old at 2 institutions. METHODS: A retrospective chart review identified patients who underwent posttraumatic open elbow contracture release by 2 surgeons at 2 institutions between 2006 and 2013. Nontraumatic contractures and arthroscopic releases were excluded. Twenty-six patients were included in this study. Mean age at the time of injury was 12 years (5 to 19 y) and at the time of surgery was 14 years (7 to 20 y). Capsulotomy, osteoplasty, removal of hardware, ulnar nerve release or transposition, and ligament reconstruction were performed through medial and lateral approaches as indicated by the pathology. Ten patients had ligament repair or stabilization, and 16 patients used a continuous passive motion (CPM) postoperatively. Outcomes included active range of motion and complications. RESULTS: Mean time from injury to surgical release was 29 months. Mean postoperative follow-up was 42 months. Elbow active flexion-extension and forearm rotation arcs both increased significantly by a mean of 49 and 70 degrees, respectively, at final follow-up. A mean 85% of intraoperative flexion-extension arc was maintained at final follow-up. Ligament repair or reconstruction and the use of a postoperative CPM did not significantly change these outcomes. Outcomes were not significantly different if our contracture release was performed within a year from injury. Patients who had surgery before our contracture release had decreased restoration of forearm rotation after release. Complications included 2 recurrent contractures (1 used a CPM and 1 did not), and 2 postoperative ulnar neuropathies (1 used a CPM and 1 did not). CONCLUSIONS: Open contracture release for posttraumatic elbow contracture in an adolescent population can significantly improve active range of motion. LEVEL OF EVIDENCE: Level 3-therapeutic.

Arthroscopic Diagnosis of the Triangular Fibrocartilage Complex Foveal Tear: A Cadaver Assessment.

PURPOSE: To determine whether the arthroscopic hook and trampoline tests are accurate and reliable diagnostic tests for foveal triangular fibrocartilage complex (TFCC) detachment. METHODS: Wrist arthroscopy was performed on 10 cadaveric upper extremities. Arthroscopic hook and trampoline tests were performed and videos recorded (baseline). The deep foveal TFCC insertion was then sharply detached. Arthroscopic hook and trampoline tests were repeated. Subsequently, the foveal detachment was repaired via an ulnar tunnel technique and the hook test was repeated for a third time. Videos were independently reviewed at 2 time points by 2 fellowship-trained hand surgeons and 1 hand surgery fellow in a randomized and blinded fashion. Hook and trampoline tests were graded as positive or negative. Proportions of categorical variables were compared via 2-tailed Fisher exact test. Inter- and intraobserver reliabilities were assessed via Cohen kappa coefficient. RESULTS: The sensitivity and specificity of the hook test for foveal detachment diagnosis were 90% and 90%, respectively. There was 90% agreement among all 3 observers for the baseline and foveal detachment hook tests. Cohen kappa coefficients for the inter- and intraobserver reliabilities of the hook test were 0.87 and 0.81, respectively. Seventeen percent of trampoline tests were positive at baseline versus 43% after foveal detachment. The trampoline test had 45% agreement between the 3 observers. Cohen kappa coefficients for the inter- and intraobserver reliabilities of the trampoline test were 0.16 and 0.63, respectively. Following ulnar tunnel repair, 20% of hook tests were positive. CONCLUSIONS: The hook test is highly sensitive, specific, and reliable for the diagnosis of isolated TFCC foveal detachment. The trampoline test has insufficient reliability to assess foveal detachment. A TFCC foveal repair using an ulnar tunnel technique returns the hook test to baseline. CLINICAL RELEVANCE: The hook test is a sensitive, specific, and reliable test for the diagnosis of isolated TFCC foveal detachment.

Prenatal Detection of Upper Limb Differences With Obstetric Ultrasound.

PURPOSE: To determine the sensitivity, specificity, and predictive values of prenatal ultrasound detection of fetal upper extremity anomalies at a single tertiary care center in a large patient cohort. Our secondary purpose was to assess factors affecting prenatal detection including the presence of associated anomalies. METHODS: We performed a retrospective review of prenatal ultrasound and postnatal clinical records from each pregnancy evaluated with a prenatal ultrasound at the Washington University Department of Obstetrics and Gynecology over a 20-year period. We searched for upper extremity anomaly diagnosis codes pre- and postnatally and correlated with clinical postnatal follow-up to determine prevalence, sensitivity, specificity, predictive values, and associated conditions. RESULTS: A total of 100,856 pregnancies were evaluated by prenatal ultrasound, which included 843 fetuses diagnosed with a musculoskeletal anomaly (prevalence, 1 of 120) and 642 with an upper extremity anomaly (prevalence, 1 of 157). The postnatally confirmed sensitivity for prenatal ultrasound detection of an upper extremity anomaly was 42%. Sensitivity was lower in cases isolated to the upper extremity (25% vs 55%). Sensitivity was highest for conditions affecting the entire upper extremity (70%-100%) and lowest for those affecting the digits alone (4%-19%). Fetuses with limb reduction defects, radial longitudinal deficiency, phocomelia, arthrogryposis, abnormal hand positioning, and cleft hand had a higher likelihood of having an associated anomaly. CONCLUSIONS: At our tertiary referral center, there was a notable prevalence of upper extremity anomalies; however, the overall sensitivity for detecting them with prenatal ultrasound was low. This was disappointing given the value of prenatal identification of anomalies for parental counseling. Prenatal diagnosis of anomalies affecting the entire upper limb was more reliable than diagnosis of more distal anomalies. TYPE OF STUDY/LEVEL OF EVIDENCE: Diagnostic III.

Frequency and Timing of Postoperative Complications After Outpatient Total Hip Arthroplasty.

Background: Although there have been several studies describing risk factors for complications after outpatient total hip arthroplasty (THA), data describing the timing of such complications is lacking. Methods: Patients who underwent outpatient or inpatient primary THA were identified in the 2012-2019 National Surgical Quality Improvement Program database. For 9 different 30-day complications, the median postoperative day of diagnosis was determined. Multivariable regressions were used to compare the risk of each complication between outpatient vs inpatient groups. Multivariable Cox proportional hazards modeling was used to evaluate the differences in the timing of each adverse event between the groups. Results: After outpatient THA, the median day of diagnosis for readmission was 12.5 (interquartile range 5-22), surgical site infection 15 (2-21), urinary tract infection 13.5 (6-19.5), deep vein thrombosis 13 (8-21), myocardial infarction 4.5 (1-7), pulmonary embolism 15 (8-25), sepsis 16 (9-26), stroke 2 (0-7), and pneumonia 6.5 (3-10). On multivariable regressions, outpatients had a lower relative risk (RR) of readmission (RR = 0.73), surgical site infection (RR = 0.72), and pneumonia (RR = 0.1), all P < .05. On multivariable cox proportional hazards modeling, there were no statistically significant differences in the timing of each complication between outpatient vs inpatient procedures (P > .05). Conclusions: The timing of complications after outpatient THA was similar to inpatient procedures. Consideration should be given to lowering thresholds for diagnostic testing after outpatient THA for each complication during the at-risk time periods identified here. Although extremely rare, this is especially important for catastrophic adverse events, which tend to occur early after discharge.