Radiographic and anatomic variations on postoperative acromion fractures after inlay and lateralized reverse shoulder arthroplasty.

INTRODUCTION: Postoperative fracture of the acromion is a complication uniquely more common after reverse shoulder arthroplasty (RSA) than other forms of shoulder arthroplasty. There is limited knowledge regarding the etiology of these fractures or the anatomic risk factors. The purpose of this study is to identify associations of the acromioclavicular (AC) joint and relative humeral and glenoid positioning on the occurrence of acromial fractures after RSA. METHODS: A retrospective case-controlled study was performed on primary RSA patients treated by a single surgeon from September 2009 to September 2019. Patients with a postoperative acromion fracture were matched in a 3:1 ratio based on gender, indication, and age to those without a fracture and with a 2-year minimum follow-up. Preoperative and the immediate postoperative radiographs were reviewed by 2 investigators to measure critical shoulder angle, acromion-humeral interval, global lateralization, delta angle, preoperative glenoid height, and the level of inlay or onlay of the humeral stem. The morphology, width, and stigmata of osteoarthritis in the AC joint were assessed using computed tomography scans taken preoperatively. RESULTS: Of a total of 920 RSAs performed, 47 (5.1%) patients suffered a postoperative acromion fracture. These patients were compared with a control group of 141 patients, with a mean age of 76.4 years and similar distributions of gender and surgical indication. Patients in both groups had similar preoperative glenoid height (P = .953) and postoperative degree of inset or offset of humeral implant relative to the anatomic neck (P = .413). There were no differences in critical shoulder angle, acromion-humeral interval, global lateralization, and delta angle both preoperatively and postoperatively between the fracture and nonfracture groups. Computed tomography analysis also showed no differences in AC joint morphology (P = .760), joint space (P = .124), and stigma of osteoarthritis (P = .161). CONCLUSION: There was no relation between the features of the AC joint and the anatomic parameters of the humerus relative to the glenoid and acromion on postoperative acromion fractures after RSA.

Iron deficiency anemia is associated with increased medical and implant-related complications and length of stay for patients undergoing total shoulder arthroplasty.

BACKGROUND: Iron deficiency anemia (IDA) is associated with decreased bone mineral density and osteoporosis; however, studies investigating the effects of IDA in patients undergoing primary total shoulder arthroplasty (TSA) have not been well studied. The purpose of this study is to utilize a nationwide administrative claims database to investigate whether patients with diagnosed IDA undergoing primary TSA have higher rates of 1) in-hospital length of stay (LOS); 2) medical complications; and 3) implant-related complications. METHODS: A retrospective review from 2005 to 2014 was conducted using the Medicare Standard Analytical Files. Patients with IDA undergoing primary TSA were identified and matched to controls without IDA, in a 1:5 ratio by age, sex, and medical comorbidities. Outcomes analyzed included in-hospital LOS and 90-day medical and implant-related complications. Mann-Whitney U tests compared in-hospital LOS, and multivariate logistic regression was used to calculate odds ratios (ORs) on the effects of IDA on postoperative complications after adjusting for age, sex, and Elixhauser Comorbidity Index. RESULTS: A total of 17,689 patients with IDA and 88,445 without IDA participated in the matched-cohort analysis, with no differences in age, gender, and comorbidities (P = .99). IDA patients were found to have significantly longer in-hospital LOS (3-days vs. 2-days, P < .0001). IDA patients were also found to have significantly higher odds of 90-day implant-related complications (OR: 1.65, P < .0001), such as periprosthetic joint infections (OR: 1.80, P < .0001) and 90-day medical complications (OR: 2.87, P < .0001), including blood transfusions (OR: 10.37, P < .0001). CONCLUSION: Patients with IDA undergoing primary TSA have significantly longer in-hospital LOS, and medical and implant-related complications. Patients were 10 times more likely to undergo a blood transfusion and 2 times more likely to have a periprosthetic fracture.

Medial Varus Proximal Tibial Resection is Superior to Pie-Crusting of the Medial Collateral Ligament During Primary Total Knee Arthroplasty.

BACKGROUND: Medial varus proximal tibial (MPT) resection or soft tissue releases (STRs) of the medial collateral ligament (MCL) in the form of pie-crusting can be performed to achieve a balanced knee in a varus deformity. Studies comparing the 2 modalities have not been addressed within the literature. Therefore, the aims of this study were to assess the following: (1) compartmental changes between the 2 methods and (2) changes in patient-reported outcome measurements. METHODS: Using our institution's total joint arthroplasty registry, patients who underwent primary total knee arthroplasty from January 1, 2017, to December 31, 2019, were identified. The MPT resection and STR patients were 1:1 matched with baseline parameters yielding 196 patients. Outcomes of interest included: changes in compartmental pressures at 10, 45, and 90° degrees and change to the Short-Form 12, Western Ontario and McMaster Universities Osteoarthritis Index, and Forgotten Joint Scores (FJSs) at the 2-year follow-up period. A P value less than .05 was used as our threshold for statistical difference. RESULTS: The MPT resection led to significant reductions in compartmental pressures at 10° [43 versus 19 pounds (lbs.), P < .0001], 45° (43 versus 27 lbs., P < .0001), and 90° degrees (27 versus 16 lbs., P < .0001) compared to STR. MPT resection also had significantly improved Short-Form 12 (47 versus 38, P < .0001), Western Ontario and McMaster Universities Osteoarthritis Index (9 versus 21, P < .0001), and Forgotten Joint Score (79 versus 68, P = .005). CONCLUSION: Bone modification was superior to pie-crusting of the MCL in achieving consistent pressure balancing and improved outcomes. The investigation can guide surgeons on the preferred method to achieve a well-balanced knee.

Mako™ Robotic-Arm Assisted Medial Unicompartmental Knee Arthroplasty: Surgical Technique from the Office to the Operating Room.

The utilization of robotic-arm assisted unicompartmental knee arthroplasty (UKA) or partial knee arthroplasty (PKA) for the treatment of medial unicompartmental osteoarthritis has continued to increase. This is in part due to the consistently reproducible accuracy and precision of implant planning, intra-operative ligament balancing software, tracking optimization software, robotic-arm assisted bone preparation, excellent survivorship rates, and improvements in many patient-reported outcomes compared to manual UKA, using the Stryker Mako™ Robotic Partial Knee System (Stryker, Mako Surgical Corp., Mahwah, New Jersey). Training in the utilization of robotic-arm assistance can be time-consuming and comes with an associated learning curve even after the in-person training and coursework is complete, like most procedures. Therefore, our aim was to describe the pre-operative planning and intra-operative surgical technique for using a robotic-arm assisted partial knee system for UKA/PKA in patients who have unicompartmental medial knee osteoarthritis. Specifically, we will discuss: 1) pre-operative planning; 2) operative setup; 3) intra-operative steps; 4) execution of the plan; and 5) trialing, implantation, and final assessments.

Robotic-Arm Assisted Lateral Unicompartmental Knee Arthroplasty: Case Series with Minimum Five-Year Follow-Up.

INTRODUCTION: Lateral unicompartmental knee arthroplasty has been shown to be a successful treatment modality for isolated lateral osteoarthritis (OA) of the knee. The reproduction of proper knee kinematics, limb alignment, as well as proper soft tissue balancing and component positioning have been shown to be of the utmost importance for a successful unicompartmental knee arthroplasty (UKA). Robotic assistance has shown to be a reliable tool in order to replicate these factors, as compared to manual instrumentation alone. Recent studies have shown the potential of robotic-assisted surgery in controlling these surgical factors for medial UKA; however, studies assessing outcomes of robotic-assisted lateral UKA (RAUKA) are lacking. Therefore, a retrospective single-center study was performed to assess outcomes of lateral RAUKA. MATERIALS AND METHODS: Patients who underwent lateral RAUKA from a single surgeon at a central institution between January 2008 and June 2017 were identified. All patients received a lateral UKA with a fixed-bearing metal backed onlay tibial component. Patients over the age of 18, with at least a five-year follow-up and a lateral UKA were contacted by phone and asked a series of questions to determine satisfaction and survivorship. Each patient was asked in a "yes" or "no" manner, if they have had their implant revised or reoperated for any reason, and a 5-point Likert scale was used to assess satisfaction. RESULTS: Data was collected from 50 patients (53 knees). Of the patients that responded: 32 (60%) were right knees; 32 (60%) were female, and average follow-up was 7.6 years (5-14 years). Of the 53 knees, one had a revision (98% survivorship). Excluding the revision, 51 (98%) of the included cases were either "very satisfied" or "satisfied" with their surgery. DISCUSSION/CONCLUSIONS: Robotic-arm assisted lateral UKA was found to have high survivorship and a satisfaction rate in patients that had at least a five-year follow-up. In the future, larger prospective comparison studies with longer follow-ups are necessary to adequately compare survivorship and satisfaction rates of robotic-assisted lateral UKA to conventional UKA.

Mid-Term Survivorship, Radiographic and Functional Outcomes of Robotic-Assisted Unicompartmental Knee Arthroplasty.

INTRODUCTION: The use of robotic-arm assistance for medial unicompartmental knee arthroplasty (RAUKA) has become an area of interest to overcome technical challenges, improve accuracy, and optimize patient outcomes. Due to the rise in osteoarthritis (OA) and robotic assistance, well-powered long-term studies are warranted. The aim of this study was to analyze midterm survivorship, radiographic changes, range of motion (ROM), and patient-reported outcome measurements (PROMs) of RAUKA. MATERIALS AND METHODS: Patients who underwent RAUKA for medial compartmental OA were identified from April 2009 to May 2014. The query yielded 162 knees with a mean follow up of 6.5 years. Primary endpoints were to compare survivorship, final mechanical axis alignment, radiographic changes, mean ROM, and changes to the following PROMs: Knee Society Score (KSS), International Knee Documentation Committee (IKDC), and Oxford Knee Score (OKS). Statistical analyses were primarily descriptive. A p-value less than 0.05 was considered statistically significant. RESULTS: There were no revisions of the primary implant, one case required exchange of polyethylene bearing and debridement for deep infection, and five cases required additional surgical intervention with implant retention. Overall survivorship was 100%. Radiographic assessment demonstrated no mechanical loosening or osteolysis surrounding the implant. Mean ROM was 3 to 121.9º. Patients demonstrated a mean functional KSS of 78.55, IKDC of 78.22, and OKS of 43.94. CONCLUSIONS: The study supports excellent mid-term outcomes in patients undergoing RAUKA for medial compartment OA. Longer term follow-up studies are necessary to determine the efficacy of this technology for patients undergoing RAUKA for medial compartment OA.

How does sleep apnea impact outcomes following primary total hip arthroplasty for femoral neck fractures: a matched-control analysis.

BACKGROUND: Cross-sectional studies have demonstrated that the prevalence of sleep apnea (SA) to be increasing within the United States. While studies have shown the association of SA and its association on complications following elective orthopedic procedures, well-powered studies investigating its impact in a traumatic setting are limited. The purpose of this study was to determine whether SA patients undergoing primary total hip arthroplasty (THA) for femoral neck fractures have higher rates of: (1) hospital lengths of stay (LOS); (2) readmissions; (3) complications; and (4) healthcare expenditures. METHODS: The 100% Medicare Standard Analytical Files was queried from 2005 to 2014 for patients who sustained femoral neck fractures and were treated with primary THA. The study group consisted of patients with concomitant diagnoses of SA, whereas patients without SA served as controls. Study group patients were matched to controls in a 1:5 ratio by age, sex, and various comorbid conditions. Demographics of the cohorts were compared using Pearson's chi-squared analyses, and multivariate logistic regression analyses were used to calculate the odds (OR) of the effects of SA on postoperative outcomes. A p value less than 0.006 was considered to be statistically significant. RESULTS: The final query yielded 24,936 patients within the study (n = 4166) and control (n = 20,770) cohorts. SA patients had significantly longer in-hospital LOS (6 vs. 5 days, p < 0.0001) but similar readmission rates (24.12 vs. 20.50%; OR: 1.03, p = 0.476). SA patients had significantly higher frequency and odds of developing medical complications (72.66 vs. 43.85%; OR: 1.57, p < 0.0001), and higher healthcare costs ($22,743.79 vs. $21,572.89, p < 0.0001). CONCLUSION: SA is associated with longer in-hospital LOS, higher rates of complications and healthcare expenditures. This study is vital as it can allow orthopaedists to educate patients with SA on the potential complications which may occur following their procedure. LEVEL OF EVIDENCE: III.

How Did Coronavirus-19 Impact the Expenses for Medical Students Applying to an Orthopaedic Surgery Residency in 2020 to 2021?

BACKGROUND: Orthopaedic surgery is one of the most competitive specialties for residency applicants. For the 2021 residency match, the coronavirus-19 pandemic introduced complexity for programs and applicants because away rotations were limited and in-person interviews were cancelled. This may have changed the landscape in terms of expenses for candidates in important ways, but this topic has been insufficiently studied. QUESTIONS/PURPOSES: Given that in 2021, students did not attend away rotations and all interviews were held virtually, we asked (1) What were the financial savings associated with this change? (2) Was medical school geographic region associated with differences in expenses when applying to residency? METHODS: A retrospective, cross-sectional analysis of the 2020 and 2021 Texas Seeking Transparency in Application to Residency Dashboard database was performed. The data were derived from an online survey of a nationwide pool of applicants from 87% (123 of 141) of US allopathic medical schools upon conclusion of the match. The response percentage was 29% (521 of 1794). We believe this nationwide dataset represents the largest and most current data for this applicant group. Responses from applicants applying to orthopaedic surgery residency in the year before the COVID-19 pandemic application changes (2020) and during COVID-19 (2021) were queried and compared. After the orthopaedic surgery match, the database was evaluated for individual (application costs, away rotation expenses, and interview expenses) and total expenses for medical school seniors applying to orthopaedic surgery residency. Applicant characteristics were compared between application cycles. The 2020 to 2021 Texas Seeking Transparency in Application to Residency Dashboard database had 521 responses (n = 263 in 2020 and n = 258 in 2021) from applicants applying to orthopaedic surgery residency. Demographic and applicant characteristics were comparable between application cycles. Median expenses are reported with percentile distributions and geographic comparisons. A Mann-Whitney U test or Kruskal-Wallis H test was used to determine whether there were statistically significant differences in expenses between years and between medical school regions at a p value threshold of < 0.05. RESULTS: For all applicants, the median total expenses (USD 7250 versus USD 2250), application costs (USD 2250 versus USD 1750), away rotation expenses (USD 2750 versus USD 250), and interview expenses (USD 2250 versus USD 75) declined in 2021 compared with 2020 (all p < 0.001). The median total savings in expenses for all applicants in 2021 compared with 2020 was USD 5000. In 2021, median total expenses were lower in all geographic regions with the greatest savings from applicants in the West (USD 6000); in addition, the difference in median total expenses between the geographic region with the highest total expenses and the lowest total expenses was lower in the pandemic year than it was in the year prior (USD 1000 versus USD 1500; p < 0.001). In 2021, there were differences in total expenses between the Northeast (USD 1750), West (USD 1750), and Central (USD 2750) regions (p < 0.001). From 2020 to 2021, only application fees from Northeast applicants differed (USD 2250 versus USD 1250; p < 0.001). In 2020, interview expenses were not different between all regions (USD 2250 Northeast and West versus USD 2750 Central and South; p = 0.19); similarly in 2021, interview expenses were similar between all regions (USD 75 versus USD 75; p = 0.82). Finally, in 2020, Northeast (USD 3250) and Western (USD 3250) applicants spent more for away rotations than Southern (USD 2750) and Central (USD 2250) applicants (p = 0.01). In 2021, applicants from schools in the South (USD 250) and Central (USD 250) regions spent more than their counterparts (USD 0; p = 0.028). CONCLUSION: In the COVID-19 application cycle, the median expenditures of orthopaedic residency candidates were USD 5000 lower than they were in the previous year; the difference can be attributed to the use of virtual interviews and the lack of away rotations. There are geographic implications, with applicants from Western United States medical schools potentially saving the most. Despite the financial savings during the 2021 match, further study related to the long-term success of the current application process (both for applicants and programs) is needed. The recommendation in May 2020 by the AOA Council of Orthopaedic Residency Directors (CORD) to limit the number of applications submitted by candidates with USMLE Step 1 scores greater than 235 did not result in any considerable decline in applications submitted or expenses. A better understanding of how differences in these expenses may influence our specialty's ability to attract socioeconomically diverse candidates would be important, and we need to explore perceived and actual financial obstacles to obtaining this diversity in the application process. Finally, avenues should be explored by program directors and chairpersons to reduce the expenses of the traditional application process while maintaining recruitment of top candidates. LEVEL OF EVIDENCE: Level IV, economic analysis.

Increased In-Hospital Lengths of Stay, Readmission Rates, Complications, and Costs in Patients Who Have Depressive Disorders Following Primary Total Hip Arthroplasty.

INTRODUCTION: Recent studies have shown the prevalence of depressive disorders has increased within the United States. Studies investigating the impact of depressive disorders following primary THA are limited. Therefore, the purpose of this study was to determine whether patients with depressive disorders have higher rates of: 1) in-hospital lengths of stay (LOS); 2) readmission rates; 3) medical complications; and 4) implant-related complications. MATERIALS AND METHODS: A retrospective query of the Humana claims database was performed. Patients undergoing primary THA with a history of depressive disorders were identified by International Classification of Disease, Ninth Revision (ICD-9), and Current Procedural Terminology (CPT) codes. Study group patients were matched to controls in a 1:5 ratio by age, sex, and comorbidities. The query yielded 67,245 patients with (n=11,255) and without (n=55,990) depressive disorders. Welch's t-tests were used to test for significance in LOS between the cohorts; whereas, logistics regression analyses were used for complications and readmissions. A p-value less than 0.003 was statistically significant. RESULTS: Patients with depressive disorders undergoing primary THA had significantly longer in-hospital LOS (6.59 days vs. 2.96 days, p <0.0001). Additionally, patients with depressive disorders had higher incidence and odds of readmission rates (46.02 vs. 35.43%; OR: 1.55, p <0.0001), medical complications (7.05 vs. 1.84%; OR: 4.04, p <0.0001), and implant-related complications (5.76 vs. 2.75%; OR: 2.16, p <0.0001) compared to patients without depressive disorders. CONCLUSION: After matching age, sex, and medical comorbidities, the results of the study demonstrate patients with depressive disorders have longer in-hospital LOS and increased rates of complications and readmission rates. The study is useful as it can allow orthopedic surgeons to properly counsel these patients of the potential complications which may arise following their procedure.

Comparison study of patient demographics and risk factors for infections following primary total hip arthroplasty for femoral neck fractures.

INTRODUCTION: While studies have shown favorable outcomes in the treatment of femoral neck fractures with the utilization of total hip arthroplasty (THA), adverse events, such as infections, can still occur. Therefore, the aims of this study were to 1) compare baseline demographics and 2) identify risk factors associated with developing either surgical site infections (SSIs) or peri-prosthetic joint infections (PJIs). MATERIALS AND METHODS: A retrospective analysis of patients who underwent primary THA for femoral neck fractures were queried from the Medicare database. The inclusion criteria consisted of patients developing SSIs within 90 days or PJIs within 3 years following the index procedure. The query yielded 2502 patients who developed infections in the form of either SSIs (n = 987) or PJIs (n = 1515) out of 57,191 patients treated for femoral neck fractures with primary THA. Primary endpoints were to compare baseline demographic profiles and determine risk factors associated with developing infections. Multivariate binomial logistic regression analyses were performed to determine the odds (OR) of developing infections. A p value less than 0.001 was considered to be statistically significant. RESULTS: Patients who developed either infections were found to be significantly different when compared to patients who did not develop infections. SSI (10 vs. 8, p < 0.0001) and PJI (9 vs. 5, p < 0.0001) patients both had significantly higher mean Elixhauser Comorbidity Index (ECI) scores compared to their counterparts. The regression model found the greatest risks for developing SSIs included hypertension (OR 1.63, p = 0.001), pathologic weight loss (OR 1.58, p < 0.0001), and iron deficiency anemia (IDA) (OR 1.48, p < 0.0001), whereas IDA (OR 2.14, p < 0.0001), pathologic weight loss (OR 1.75, p < 0.0001), and rheumatoid arthritis (OR 1.57, p < 0.0001) increased the odds for PJIs. CONCLUSION: This study can be utilized by orthopedic surgeons and other healthcare professionals to adequately educate these patients of the complications which may occur following their surgery.

A matched-control study on the effects of depressive disorders following open reduction and internal fixation for acetabular fractures.

INTRODUCTION: The World Health Organization (WHO) postulates that depressive disorders (DD) will be the leading cause of morbidity and mortality by 2030. Studies evaluating the association of DD following open reduction and internal fixation (ORIF) for the treatment of acetabular fractures are limited. Therefore, the purpose of this matched-control study was to determine whether DD patients undergoing ORIF for acetabular fractures have higher rates of: (1) in-hospital lengths of stay (LOS); (2) readmissions; (3) medical complications; and (4) costs of care. MATERIALS AND METHODS: A retrospective query from the 100% Medicare Standard Analytical Files (SAF) was performed to identify patients who underwent ORIF for acetabular fractures. The study group consisted of those patients with DD, whereas patients without the condition served as controls. Primary endpoints of the study were to compare in-hospital LOS, readmission rates, ninety-day medical complications, and costs of care. A p-value less than 0.01 was considered statistically significant. RESULTS: The query yielded 7084 patients within the study (ORIF = 1187, control = 5897). DD patients were found to have significantly longer in-hospital LOS (11 days vs. 10 days, p < 0.0001); however, odds (OR) of readmission rates were similar (23.16 vs. 18.68%; OR: 0.91, p = 0.26). Multivariate regression demonstrated DD to be associated with significantly higher (67.69 vs. 25.54%; OR: 2.64, p < 0.0001) 90-day medical complications. DD patients had significantly higher day of surgery ($30,505.93 vs. $28,424.85, p < 0.0001) and total global 90-day costs ($41,721.98 vs. $37,330.16, p < 0.0001) of care. CONCLUSION: After adjusting for covariates, DD is associated with longer in-hospital, complications, and costs of care in patients undergoing ORIF for the treatment of acetabular fractures, whereas readmission rates are similar. The study is vital as it can be used by orthopaedists and healthcare professionals to adequately educate these patients of the potential outcomes following their surgical procedure.

Reasons and Risk Factors for Emergency Department Visits After Primary Total Knee Arthroplasty: An Analysis of 1.3 Million Patients.

BACKGROUND: Well-powered studies investigating the relationship of emergency department (ED) visits and total knee arthroplasty (TKA) are limited. Therefore, the specific aims of this study were to: 1) compare patient demographics of patients who did and did not have an ED visit; and for the visits, identified: 2) leading reasons; and 3) risk factors for ED visits (prearthroplasty/postarthroplasty). METHODS: Patients undergoing primary TKA who had an ED visit within 90 days after their index procedure were identified from a nationwide database. The query yielded 1,364,655 patients who did (n = 5689) and did not have (n = 1,358,966) an ED visit. Baseline demographics such as age, sex, and comorbidity prevalence between the two cohorts; reasons for ED visits; and prearthroplasty and postarthroplasty risk factors were analyzed. Odds ratios (ORs) of ED visits were assessed using multivariate binomial logistic regression analyses. A P-value less than 0.001 was considered statistically significant. RESULTS: Patients who did and did not have ED visits differed with respect to age (P < .0001) and mean Elixhauser Comorbidity Index scores (9 vs 6, P < .0001). Musculoskeletal etiologies were the most common reason for ED visits. Hypertension was the greatest contributor to ED visits prearthroplasty and postarthroplasty. Comorbid conditions associated with ED visits postarthroplasty included peripheral vascular disease (OR: 1.61, P < .0001), coagulopathy (OR: 1.58, P < .0001), and rheumatoid arthritis (OR: 1.56, P < .0001). CONCLUSION: By identifying demographic patterns of patients, reasons, and risk factors, the information found from this study can help identify targets for quality improvement to potentially reduce the incidence of ED visits after primary TKA.

Clinical and Administrative Databases Used in Lower Extremity Arthroplasty Research.

BACKGROUND: The use of national databases in lower extremity arthroplasty research has grown rapidly in recent years. We aimed to better characterize available databases by: (1) quantifying the number of these studies in the highest impact arthroplasty journals; (2) comparing respective sample sizes; and (3) contrasting their measured variables/outcomes. METHODS: An extensive literature search was conducted to identify all database studies in the top 12 highest impact factor journals that published arthroplasty research between January 1, 2018 and December 31, 2019. A total of 5070 publications were identified. These studies were sorted by both database utilized and journal published. Tables were constructed to compare/contrast databases by metrics and measured outcome parameters including coding, patient sample size, preoperative comorbidities, postoperative complications, and limitations/barriers to their use. RESULTS: Four hundred twenty-six database studies (8.4%, range 0.4%-29.7% per journal) were identified, of which 139 were from non-English-speaking arthroplasty databases. Among English-speaking arthroplasty databases, the 5 most common sources were National Surgical Quality Improvement Project (n = 72), Medicare (n = 62, 39 from Medicare Claims and 23 from PearlDiver), Nationwide Inpatient Sample (n = 35), PearlDiver non-Medicare private insurance (n = 18), and Statewide Planning and Research Cooperative System (n = 18). Metrics, outcome parameters, and features of commonly used registries were reviewed. CONCLUSION: Database studies constitute an important part of arthroplasty-specific orthopedic research. Their use will continue to grow in the future, and it would be beneficial for clinicians/researchers to be aware of and familiarize themselves with their features to understand which are most appropriate for their work.

Paget's Disease in Primary Total Hip Arthroplasty Is Associated With Greater In-Hospital Lengths of Stay, Costs, and Complications.

BACKGROUND: There are few well-powered studies investigating the association of Paget's disease of bone on patients undergoing primary total hip arthroplasty (THA). This study utilized a nationwide database to determine whether Paget's patients undergoing primary THA are associated with higher rates of (1) lengths of stay (LOS); (2) costs; and (3) complications (medical/surgical and implant-related). METHODS: Using International Classification of Diseases, Ninth Revision and Current Procedural Terminology codes, Paget's patients undergoing primary THA were identified and matched to non-Paget's patients in a 1:5 ratio by age, sex, and comorbidities utilizing the PearlDiver database. This resulted in 21,714 patients in Paget's (n = 3619) and non-Paget's (n = 18,095) cohorts. Outcomes assessed included LOS, episode-of-care costs, medical/surgical complications, and implant-related complications. A P value less than .003 was considered statistically significant. RESULTS: Compared to the matched cohort, Paget's patients undergoing primary THA had significantly longer LOS (P < .0001), higher 90-day total global episode-of-care costs (P < .0001), higher 90-day medical and surgical complications (P < .0001), and higher implant-related complications (P < .0001). CONCLUSION: We found that Paget's was associated with higher rates of LOS, costs, and complications. Although there was an association found, the risk appears reasonably low compared to the matched cohort. The study can be utilized by orthopedic professionals to counsel and educate these patients of potential complications which may occur following their procedure.

Impact of Postoperative Zolpidem Use on Primary Total Knee Arthroplasty: A Retrospective Matched-Controlled Analysis of a Private Insurance Database.

INTRODUCTION: Zolpidem has gained popularity as a pharmaceutical therapy for insomnia, being the most prescribed hypnotic in the United States today. However, it is associated with increased mortality and morbidity. Literature regarding zolpidem use in the total knee arthroplasty (TKA) population is limited. The aim of the study was to analyze postoperative zolpidem use in the TKA population regarding medical and implant complications, falls, and readmission. METHODS: The study group was queried according to zolpidem use. Controls consisted of patients who underwent primary TKA without a history of hypnotic drug use. Study group patients were matched to controls in a 1:5 ratio by demographics and comorbidities. Results yielded 99,178 study participants and 495,795 controls. Primary endpoints included 90-day medical and implant complications, fall risk, and readmission. Chi-squared test was used to compare categorical variables. Multivariate logistic regression was used to calculate odds (OR) for complications, fall risk, and readmission. A P value less than 0.05 was considered statistically significant. RESULTS: Study group patients had increased odds of medical complications (OR: 1.76, 95% CI: 1.71-1.82, P < .0001) and implant complications (OR: 1.35, 95% CI: 1.23-1.47, P < .0001) compared to controls. Furthermore, patients in the study group were found to have an increased risk of 90- day falls (OR: 1.16, 95% CI: 1.11-1.21, P < .0001). Readmission was similar to controls (5.10% vs 4.84%, P = .12). CONCLUSION: Zolpidem use following primary TKA is associated with the risk of morbidity and falls. The findings are consistent with the literature regarding zolpidem. These findings may affect discussion between orthopedic surgeons and patients in the decision-making process prior to undergoing TKA.

Higher Patient Complexities are Associated with Increased Length of Stay, Complications, and Readmissions After Total Hip Arthroplasty.

INTRODUCTION: There is an increased incidence of complex patients undergoing total hip arthroplasty (THA), which demands a rigorous preoperative, intraoperative, and postoperative assessment. It is important how increases in patient complexity impact a variety of patient outcomes. Therefore, the purpose of our study is to determine if a higher Elixhauser Comorbidity Index (ECI), a measure of patient complexity, is correlated with: 1) longer hospital length of stay; 2) increased 90-day medical complications; 3) higher 90-day readmissions; and 4) greater two-year implant-related complications following primary THA. MATERIALS AND METHODS: Patients undergoing primary THA from January 1, 2004 to December 31, 2015 were queried from the Medicare Standard Analytical Files using the International Classification of Disease, ninth revision (ICD-9) procedure code 81.51. The queried patients (387,831) were filtered by ECI scores of 1 to 5. Patients who have ECI scores of 2 to 5 represented the study cohorts and were matched according to age and sex to patients who have the lowest ECI score (ECI of 1). All cohorts were longitudinally followed to assess and compare hospital length of stay, 90-day medical complications, 90-day readmissions, and two-year implant-related complications. We compared odds-ratios (OR), 95% confidence intervals (95% CI), and p-values using logistic regression analyses and Welch's t-tests. RESULTS: Patients who have ECI scores greater than 1 had higher hospital length of stay (p<0.001), 90-day medical complications (p<0.001), 90-day readmissions (p<0.001), and two-year implant-related complications (p<0.001). Patients who have an ECI score of 2 (1.26, 95% CI: 1.20-1.32), ECI of 3 (1.61, 95% CI: 1.53-1.69), ECI of 4 (2.05, 95% CI: 1.95-2.14), and ECI of 5 (2.32, 95% CI: 2.21-2.43) had an increasing trend for readmissions, with higher ECI scores correlating with greater odds of readmission following primary THA. Two-year implant-related complications also showed a similar increasing trend with greater patient complexity. Patients who had an ECI score of 5 (2.54, 95% CI: 2.39-2.69) had more implant-related complications compared to patients who had an ECI score of 2 (1.39, 95% CI:1.31-1.48). CONCLUSION: The results of this study illustrate that a higher Elixhauser-Comorbidity Index is an independent risk factor for longer hospital length of stay, higher 90-day medical complications, greater 90-day readmissions, and increased two-year implant-related complications following primary THA. This study is important as it further defines and heightens awareness of adverse events for complex patients undergoing this procedure. Future studies can examine if these events can potentially be mitigated through reductions in ECI scores prior to surgery and increased incentives for the healthcare team.

Comparison study of patient demographics and risk factors for surgical site infections following open reduction and internal fixation for lateral malleolar ankle fractures within the medicare population.

BACKGROUND: The purpose of this study was to analyze a comprehensive database to 1) compare patient demographic profiles; and 2) identify patient-related risk factors for surgical site infections (SSIs) following open reduction and internal fixation (ORIF) for lateral malleolar ankle fractures. METHODS: Patients treated with ORIF for lateral malleolar ankle fractures that developed SSIs within 1-year following the procedure were identified. Study group demographics were compared to a control cohort and risks for developing SSI were calculated using multivariate logistic regression analysis. RESULTS: There were statistically significant differences between the control group and patients with SSIs. The study showed that morbidly obese patients, peripheral vascular disease, and electrolyte/fluid imbalance were the greatest risk factors for developing SSIs following ORIF for lateral malleolar fractures. CONCLUSION: The study is useful as it can allow orthopaedists to optimize these high-risk patients to potentially mitigate this adverse event.

Opioid Use Disorder Is Associated with an Increased Risk of Infection after Total Joint Arthroplasty: A Large Database Study.

BACKGROUND: Recent studies have shown that patients with opioid use disorder have impaired immunity. However, few studies with large patient populations have evaluated the risks of surgical site infection (SSI) and prosthetic joint infection (PJI) with opioid use disorder after total joint arthroplasty (TJA), and there is a lack of evidence for revision TJA in particular. QUESTIONS/PURPOSES: Are patients with opioid use disorder who undergo (1) primary THA, (2) primary TKA, (3) revision THA, or (4) revision TKA at a higher risk of experiencing SSIs 90 days after surgery or PJIs 2 years after surgery than those who do not have opioid use disorder? METHODS: All primary and revision TJAs performed between 2005 and 2014 were identified from the Medicare Analytical Files of the PearlDiver Supercomputer using ICD-9 codes. This database is one of the largest nationwide databases; it comprehensively and longitudinally tracks patients based on all insurance claims rather than particular hospital visits, and has a low error rate (estimated at 1.3%). Boolean command operators were used to form a study group of patients with a history of opioid use disorder before surgery. ICD-9 diagnosis codes 304.00 to 304.02 and 305.50 to 305.52 were used to identify patients with opioid use disorder. Study group patients were matched 1:1 to control participants without opioid use disorder undergoing TJA, according to age, sex, and comorbidity burden (Elixhauser comorbidity index [ECI]). The ECI is comprised of 31 different comorbidities and can be used for large administrative databases. The query yielded a study population of 54,332 patients: 14,944 undergoing primary THA (opioid use disorder: n = 7472), 23,680 undergoing primary TKA (opioid use disorder: n = 11,840), 8116 undergoing revision THA (opioid use disorder: n = 4058), and 7592 undergoing revision TKA (opioid use disorder: n = 3796). The primary outcomes analyzed were SSI at 90 days and PJI at 2 years postoperatively, which were identified with ICD-9 codes. Logistic regression analyses were performed to calculate the risk that an infection would develop in a patient with opioid use disorder compared with the matched control patients without opioid use disorder. RESULTS: Patients with opioid use disorder undergoing primary THA had an increased risk of SSI at 90 days (OR 1.85 [95% CI 1.51 to 2.25]; p < 0.001) and PJI at 2 years (OR 1.66 [95% CI 1.42 to 1.93]; p < 0.001). Compared with matched controls, opioid use disorder patients undergoing primary TKA had an increased risk of SSI at 90 days (OR 1.72 [95% CI 1.46 to 2.02]; p < 0.001) and PJI at 2 years (OR 1.31 [95% CI 1.16 to 1.47]; p < 0.001). Similarly, for revision THAs, there was an increase in 90-day SSIs (OR 1.89 [95% CI 1.53 to 2.32]; p < 0.001) and 2-year PJIs (OR 4.24 [95% CI 3.67 to 4.89]; p < 0.001). The same held for revision TKAs for 90-day SSIs (OR 1.88 [95% CI 1.53 to 2.29]; p < 0.001) and 2-year PJIs (OR 4.94 [95% CI 4.24 to 5.76]; p < 0.001). CONCLUSIONS: After accounting for age, sex, and comorbidity burden, these results revealed that patients with opioid use disorder undergoing TJA were at increased risk of having SSIs and PJIs. Based on these findings, healthcare systems and/or administrators should recognize the increased associated PJI and SSI risks in patients with opioid use disorder and enact clinical policies that reflect these associated risks. Additionally, these findings should encourage surgeons to pursue multidisciplinary approaches to help patients reduce their opioid consumption before their arthroplasty procedure. LEVEL OF EVIDENCE: Level III, therapeutic study.

What Are Risk Factors for Infection after Primary or Revision Total Joint Arthroplasty in Patients Older Than 80 Years?

BACKGROUND: Patients older than 80 years of age form an increasing proportion of the patient population undergoing total joint arthroplasty (TJA). With increasing life expectancy and the success of TJA, orthopaedic surgeons are more likely to operate on patients older than 80 years than ever before. Given that most other studies focus on younger populations, only evaluate primary TJA, or limit patient populations to institutional or regional data, we felt a large-database, nationwide analysis of this demographic cohort was warranted, and we wished to consider both primary and revision TJA. QUESTIONS/PURPOSES: In this study, we sought to investigate the risk factors for surgical site infections (SSIs) at 90 days and periprosthetic joint infections (PJIs) at 2 years after surgery in patients aged 80 years and older undergoing (1) primary and (2) revision lower extremity TJA. METHODS: All patients aged 80 years or older who underwent primary or revision TJA between 2005 and 2014 were identified using the Medicare Analytical Files of the PearlDiver Supercomputer using ICD-9 codes. This database is unique in that it is one of the largest nationwide databases, and so it provides a large enough sample size of patients 80 years or older. Additionally, this database provides comprehensive and longitudinal patient data tracking, and a low error rate. Our final cohort consisted of 503,241 patients (TKA: n = 275,717; THA: n = 162,489; revision TKA: n = 28,779; revision THA: n = 36,256). Multivariate logistic regression models were constructed to evaluate the association of risk factors on the incidences of 90-day SSI and 2-year PJI. Variables such as sex, diabetes, BMI, and congestive heart failure, were included in the multivariate regression models. Several high-risk comorbidities as identified by the Charlson and Elixhauser comorbidity indices were selected to construct the models. We performed a Bonferroni-adjusted correction to account for the fact that multiple statistical comparisons were made, with a p value < 0.002 being considered statistically significant. RESULTS: For primary TKA patients, an increased risk of 90-day SSIs was associated with male sex (OR 1.28 [95% CI 1.25 to 1.52]; p < 0.001), BMI greater than 25 k/m (p < 0.001), and other comorbidities. For primary THA patients, an increased risk of 90-day SSIs was associated with patients with obesity (BMI 30-39 kg/m; OR 1.91 [95% CI 1.60 to 2.26]; p < 0.001) and those with morbid obesity (BMI 40-70 kg/m; OR 2.58 [95% CI 1.95 to 3.36]; p < 0.001). For revision TKA patients, an increased risk of SSI was associated with iron-deficiency anemia (OR 1.82 [95% CI 1.37 to 2.28]; p < 0.001). For revision THA patients, electrolyte imbalance (OR 1.48 [95% CI 1.23 to 1.79]; p < 0.001) and iron-deficiency anemia (OR 1.63 [95% CI 1.35 to 1.99]; p < 0.001) were associated with an increased risk of 90-day SSI. Similar associations were noted for PJI in each cohort. CONCLUSIONS: These findings show that in this population, male sex, obesity, hypertension, iron-deficiency anemia, among other high-risk comorbidities are associated with a higher risk of SSIs and PJIs. Based on these findings, orthopaedic surgeons should actively engage in comanagement strategies with internists and other specialists to address modifiable risk factors through practices such as weight management programs, blood pressure reduction, and electrolyte balancing. Furthermore, this data should encourage healthcare systems and policy makers to recognize that this patient demographic is at increased risks for PJI or SSI, and these risks must be considered when negotiating payment bundles. LEVEL OF EVIDENCE: Level III, therapeutic study.

Comparison Study of Patient Demographics, Risk Factors, and Lengths of Stay for Postoperative Ileus After Primary Total Knee Arthroplasty.

BACKGROUND: Postoperative ileus is a potential complication after orthopedic surgery, which has not been well studied after total knee arthroplasty (TKA). The aims of this study were to analyze rates of postoperative ileus; patient demographic profiles; in-hospital lengths of stay (LOS); and patient-related risk factors for postoperative ileus after primary TKA. METHODS: A query was performed from January 1, 2005 to March 31, 2014 using the Medicare Standard Analytical Files. Patients who underwent primary TKA and developed postoperative ileus within 3 days after their index procedure were identified. Patients who did not develop ileus represented controls. Primary outcomes analyzed and compared included patient demographics, risk factors, and in-hospital LOS. A P value less than .05 was considered statistically significant. RESULTS: Ileus patients were older, more likely to be male, and had higher Elixhauser-Comorbidity Index scores (8 vs 6; P < .0001) compared with controls. Male patients (odds ratio [OR], 2.12; P < .0001), patients with preoperative electrolyte/fluid imbalance (OR, 3.40; P < .001), patients older than 70 years (OR, 1.62-2.33; P < .015), and body mass indices greater than 30 kg/m2 (OR, 1.79-2.00; P < .001) were at the greatest risk of developing ileus. In addition, ileus patients had significantly longer in-hospital LOS (5.42 vs 3.22 days; P < .001). CONCLUSION: The study demonstrated differences in patient demographics, patient-related risk factors, and an increased in-hospital LOS for ileus patients after primary TKA. The study is important as it can allow orthopedists to properly identify and optimize patients with certain risk factors to potentially mitigate this adverse event from occurring.