The Impact of Travel Distance on Patient-Reported Outcomes Following Primary Total Hip Arthroplasty.

INTRODUCTION: Total hip arthroplasties (THAs) are increasingly being performed at high-volume centers, causing some patients to travel further distances to receive care. Concerns remain that increased travel distance limits follow-up, which may impact outcomes and early return to the hospital. The purpose of this study is to evaluate the impact of travel distance on 90-day patient reported outcomes (PROs) and 90-day complication rates. METHODS: Patients undergoing inpatient primary THA at a single center by one of three surgeons between 2017 and 2021 were retrospectively reviewed. Patients whose local and distant medical records were available were included. Patients who lived > 40 miles from the location or follow-up were labeled as "travelers," and those < 40 miles were "locals." Primary outcomes included PROs as measured by Veterans Rand 12 Item Health Survey (VR-12), Hip Harris Score (HHS), and Hip Dysfunction and Osteoarthritis Outcome Score for Joint Replacement (HOOS JR). Secondary outcomes included rates of 90-day medical complications, emergency department (ED) visits, unplanned readmissions, and reoperations. RESULTS: A total of 413 patients were analyzed at a mean of 897.1 days (range, 92 to 2196) including 96 travelers. Travelers averaged 96.1 miles for follow-up (range, 40.1 to 678 miles), and locals averaged 14.1 miles for follow-up (range, 0.3 to 39.8 miles). There were no significant differences in the percentage of patients achieving minimal clinically important difference (MCID) in PROs. There was no difference in the rate of 90-day medical complications, 90-day readmissions, and reoperations. Local patients were significantly more likely to have unplanned post-operative ED visits (travelers = 0%, locals = 7.4%, P = 0.003). DISCUSSION: Travelers did not demonstrate any significant differences with respect to rates of achieving MCID in PROs or 90-day complication rates. These data suggest that increased travel distance to treatment centers does not impact outcomes following primary THA.

Fragility Index Analysis of the 2018 Clinical Practice Guidelines on Tranexamic Acid Use in Total Joint Arthroplasty.

BACKGROUND: The 2018 American Association of Hip and Knee Surgeons clinical practice guideline (CPG) 'tranexamic acid use in total joint arthroplasty' evaluated the efficacy and safety of tranexamic acid in primary total joint arthroplasty. The following review assessed the statistical fragility of the randomized controlled trial (RCT) outcomes on which the CPG recommendations were based using a fragility analysis. METHODS: All dichotomous outcomes from the RCTs used to guide the CPG from its associated network, and direct meta-analyses were analyzed. Fragility and reverse fragility indices (FI and rFI) and quotients were calculated for each outcome. The mean indices and quotients were calculated for each guideline question, outcome category, and comparison of tranexamic dose, formulation, and administration timing. RESULTS: This review evaluated 403 dichotomous outcomes on transfusion and complication rates associated with tranexamic acid (TXA) administration. The mean FI of significant outcomes of the CPG was 5.23, and the mean rFI of nonsignificant outcomes was 5.80. Outcomes assessing complication rates had a mean rFI of 6.48. Most outcomes on transfusion in categories comparing TXA to placebo administration had higher mean FIs than rFIs, and all outcomes comparing transfusion risk associated with different TXA formulations and doses had higher mean rFIs than FI or no associated significant outcomes. CONCLUSIONS: The rFI and FIs calculated for this CPG are comparable to or higher than mean values reported across orthopaedic literature, indicating the relative statistical stability of its included outcomes. As we learn more about fragility analyses and their potential applications, this type of statistical analysis shows promise as a useful tool to incorporate into future guidelines to assess the quality of RCTs and evaluate the strength of recommendations.

Multimodal Analgesia and Small Opioid Prescriptions are the New Standard in Total Joint Arthroplasty: A Survey of the American Association of Hip and Knee Surgeons Membership.

BACKGROUND: The purpose of this survey study was to assess the current analgesia and anesthesia practices used by total joint arthroplasty surgeon members of the American Association of Hip and Knee Surgeons (AAHKS) as well as identify changes in practice made by AAHKS members over time. METHODS: A survey of 37 questions was created and approved by the AAHKS Research Committee. The survey was distributed to all 3,243 practicing adult reconstruction surgeon members of AAHKS in May 2023. Results were compared to a nearly identical survey sent out to all board-certified adult reconstruction surgeon members of AAHKS 5 years previously in November 2018. RESULTS: There were 527 responses (16%) to the survey. Since 2018, the mean number of opioid pills prescribed after total joint arthroplasty has declined significantly from 49 to 32 pills after total knee arthroplasty (TKA) and from 44 to 18 pills after total hip arthroplasty (THA). The use of multimodal analgesics in addition to opioids has also increased over the past 5 years from 74 to 93%. The most common medications utilized include nonsteroidal anti-inflammatories (98%), acetaminophen (80%), and gabapentinoids (32%). A majority of surgeons (78%) still use a spinal for TKA and THA. However, there has been an increase in the number of surgeons using peripheral nerve blocks for TKA from 69% in 2018 to 84% in 2023. The routine use of periarticular injection or local infiltration anesthesia in THA and TKA has also increased over the past 5 years from 80 to 86%. CONCLUSIONS: Since 2018, there has been increased adoption of multimodal analgesia and anesthesia, and improved consensus regarding the optimal regimen among surveyed arthroplasty surgeon members of AAHKS. The number of opioid pills prescribed after THA and TKA has declined significantly over the past 5 years.

Unicompartmental knee arthroplasty in octogenarians: An analysis of 1,466 patients with 2-year follow-up.

INTRODUCTION: Unicompartmental knee arthroplasty (UKA) has been shown to improve pain and function in appropriately selected patients. Limited data exists regarding outcomes and complication rates following UKA among octogenarians. METHODS: The PearlDiver Mariner database was queried for patients undergoing primary UKA between 2010-2022. Patients < 80 years old were matched 4:1 to the octogenarian cohort (≥80 years old) by sex, year, Elixhauser Comorbidity Index (ECI), tobacco use, obesity, and diabetes. A total of 1,334 octogenarians and 5,313 controls were included in our analysis. Multivariate logistic regression was utilized to compare medical complications at 90-days post-operatively and surgical complications at 1- and 2-years post-operatively. Our regression analysis controlled for sex, ECI, tobacco use, obesity, and diabetes. RESULTS: Octogenarians had an increased risk of acute kidney injury (OR: 2.306, 95% CI: 1.393-3.749; p < 0.001), pneumonia (OR: 2.367, 95% CI: 1.301-4.189; p = 0.003), UTI (OR: 1.846, 95% CI: 1.304-2.583; p < 0.001), ED visits (OR: 2.229, 95% CI: 1.586-3.105; p < 0.001), and any complication (OR: 1.575, 95% CI: 1.304-1.895; p < 0.001) at 90-days post-operatively. Octogenarians had lower odds of all-cause revision at 2-years (OR: 0.607, 95% CI: 0.382-0.923; p = 0.026). No differences were demonstrated between cohorts in rates of PJI (OR: 0.832, 95% CI: 0.334-1.796; p = 0.664), periprosthetic fracture (OR: 0.516, 95% CI: 0.120-1.520; p = 0.289), or aseptic loosening (OR: 0.285, 95% CI: 0.045-1.203; p = 0.088) at 2-years. DISCUSSION: These findings suggest that despite an increased risk of certain medical complications within the acute post-operative period, octogenarians undergoing UKA experienced similar rates of surgical complications to younger matched controls at 2-year follow-up.

Total Knee Arthroplasty in Patients with Cerebral Palsy: A Large Database Analysis.

Cerebral palsy (CP) is a neurodevelopmental condition that can result in altered gait biomechanics, joint dysfunction, and imbalance. The complications associated with total knee arthroplasty (TKA) in patients with CP have not yet been well described. Therefore, our analysis sought to compare the 90-day and 2-year complications following TKA in patients with and without CP. The PearlDiver Mariner database was utilized to identify patients with CP undergoing primary TKA between 2010 and 2020. This cohort was matched 1:4 to a control cohort without neurodegenerative disorders based on age, sex, Elixhauser Comorbidity Index (ECI), tobacco use, obesity, and diabetes. A total of 3,257 patients (657 CP patients 2,600 controls) were included in our final analysis. A multivariable logistic regression analysis was utilized to determine the risk of CP on medical and surgical complications at 90 days and all-cause revision rates at 2 years. Patients with CP had an increased risk of acute kidney injury (odds ratio [OR]: 1.66; 95% confidence interval [CI]: 1.07-2.5; p = 0.019), pneumonia (OR: 5.63; 95% CI: 3.69-8.67; p < 0.001), urinary tract infection (OR: 5.01; 95% CI: 3.85-6.52; p < 0.001), and transfusion (OR: 2.21; 95% CI: 1.50-3.23; p < 0.001). CP patients additionally had a higher incidence of emergency department (ED) visits (OR: 5.24; 95% CI: 3.76-7.32; p < 0.001) and readmissions (OR: 5.24; 95% CI: 2.57-4.96; p < 0.001). There were no differences in rates of periprosthetic joint infection (PJI; OR: 1.23; 95% CI: 0.69-2.10; p = 0.463), surgical site infection (SSI; OR: 0.51; 95% CI: 0.12-1.46; p = 0.463), and reoperation (OR: 1.35; 95% CI: 0.71-2.43; p = 0.339) at 90 days postoperatively. The all-cause revision rates at 2 years were comparable (OR: 1.02; 95% CI: 0.67-1.51; p = 0.927). In this database review, we found that CP patients have a higher risk of medical complications in the acute postoperative period following TKA. The 90-day surgical complication and 2-year revision rates in CP patients were comparable to matched controls.

Is Hospital-Based Outpatient Revision Total Knee Arthroplasty Safe? An Analysis of 2,171 Outpatient Aseptic Revision Procedures.

BACKGROUND: Outpatient primary total knee arthroplasty (TKA) has been well-established as a safe and effective procedure; however, the safety of outpatient revision TKA remains unclear. Therefore, this study utilized a large database to compare outcomes between outpatient and inpatient revision TKA. METHODS: An all-payor database was queried to identify patients undergoing revision TKA from 2010 to 2022. Patients who had diagnosis codes related to periprosthetic joint infection (PJI) were excluded. Outpatient surgery was defined as a length of stay < 24 hours. Cohorts were matched by age, sex, Elixhauser Comorbidity Index, comorbidities (diabetes, obesity, tobacco use), components revised (1-versus 2-component), and revision etiology. Medical complications at 90 days and surgical complications at 1 and 2 years postoperatively were evaluated through multivariate logistic regression. A total of 4,342 aseptic revision TKAs were included. RESULTS: No differences in patient characteristics, procedure type, or revision etiologies were seen between groups. The outpatient cohort had a lower risk of PJI (odds ratio (OR): 0.547, 95% confidence interval (CI): 0.337 to 0.869; P = .012), wound dehiscence (OR: 0.393, 95% CI: 0.225 to 0.658; P < .001), transfusion (OR: 0.241, 95% CI: 0.055 to 0.750; P = .027), reoperation (OR: 0.508, 95% CI: 0.305 to 0.822; P = .007), and any complication (OR: 0.696, 95% CI: 0.584 to 0.829; P < .001) at 90 days postoperatively. At 1 year and 2 years postoperatively, outpatient revision TKA patients had a lower incidence of revision for PJI (OR: 0.332, 95% CI: 0.131 to 0.743; P = .011 and OR: 0.446, 95% CI; 0.217 to 0.859; P = .020, respectively) and all-cause revision (OR: 0.518, 95% CI: 0.377 to 0.706; P < .001 and OR: 0.548, 95% CI: 0.422 to 0.712; P < .001, respectively). CONCLUSIONS: Our findings suggest that revision TKA can be safely performed on an outpatient basis in appropriately selected patients who do not have an increased risk of adverse events relative to inpatient revision TKA. However, we could not ascertain case complexity in either cohort, and despite controlling for several potential confounders, other less tangible differences could exist between groups.

Revision Hip Arthroplasty Performed by Fellowship-Trained Versus Non-Fellowship-Trained Surgeons: A Comparison of Perioperative Management and Complications.

BACKGROUND: Successful revision hip arthroplasty (rTHA) requires major resource allocation and a surgical team adept at managing these complex cases. The purpose of this study was to compare the results of rTHA performed by fellowship-trained and non-fellowship-trained surgeons. METHODS: A national administrative database was utilized to identify 5,880 patients who underwent aseptic rTHA and 1,622 patients who underwent head-liner exchange for infection by fellowship-trained and non-fellowship-trained surgeons from 2010 to 2020 with a 5-year follow-up. Postoperative opioid and anticoagulant prescriptions were compared among surgeons. Patients treated by fellowship-trained and non-fellowship-trained surgeons had propensity scores matched based on age, sex, comorbidity index, and diagnosis. The 5-year surgical complications were compared using descriptive statistics. Multivariable analysis was performed to determine the odds of failure following head-liner exchange when performed by a fellowship-trained versus non-fellowship-trained surgeon. RESULTS: Aseptic rTHA patients treated by fellowship-trained surgeons received fewer opioids (132 versus 165 milligram morphine equivalents per patient) and nonaspirin anticoagulants (21.4 versus 32.0%, P < .001). Fellowship-training was associated with lower dislocation rates (9.9 versus 14.2%, P = .011), fewer postoperative infections, and fewer periprosthetic fractures and re-revisions (15.2 versus 21.3%, P < .001). Head-liner exchange for infection performed by fellowship-trained surgeons was associated with lower odds of failure (31.2 versus 45.7%, odds ratio 0.76, 95% confidence interval 0.62 to 0.91, P < .001). CONCLUSIONS: rTHA performed by adult reconstruction fellowship-trained surgeons results in fewer re-revisions in aseptic cases and head-liner exchanges. Variations in resources, volumes, and perioperative protocols may account for some of the differences.

The Ideal Timing of Bilateral Total Knee Arthroplasty: Simultaneous Versus Staged.

Objectives: The ideal timing for patients undergoing bilateral total knee arthroplasty (TKA) remains unknown. The purpose of this study was to compare 90-day outcomes between unilateral, simultaneous bilateral, and staged bilateral TKA. Methods: The PearlDiver database was used to retrospectively identify 231,119 patients undergoing primary TKA during 2015-2020, of which 67,956 (29.4%) were bilateral. Bilateral TKA patients were divided into cohorts of simultaneous bilateral TKA and staged bilateral TKA at 1-14 days, 15-30 days, 31-90 days, and 91-365 days. Each bilateral TKA cohort underwent one-to-one matching with unilateral TKA patients based on age, gender, year, Elixhauser Comorbidity Index (ECI), and a history of obesity, diabetes, and tobacco use. Ninety-day outcomes were compared between matched groups via univariate and multivariate analysis. In staged bilateral TKA groups, outcomes were collected beginning after the second TKA. Results: Compared to unilateral TKA, simultaneous bilateral TKA was associated with higher rates of venous thromboembolism (VTE; odds ratio [OR] 1.28, 95% confidence interval [CI] 1.07-1.54, p=0.007), acute kidney injury (AKI; OR 1.47, CI 1.17-1.84, p=0.001), blood transfusion (OR 6.81, CI 5.43-8.65, p<0.001), and any complication (OR 1.63, CI 1.49-1.78, p<0.001). Staged bilateral TKA at any time interval studied was associated with a similar or decreased risk of individual complications, emergency department visits, readmissions, reoperations, and any complication relative to unilateral TKA. Conclusion: Simultaneous bilateral TKA is associated with an increased risk of adverse events compared to unilateral TKA. However, bilateral TKA staged at a short interval appears safe in appropriately selected patients.

Fretting and Tribocorrosion of Modular Dual Mobility Liners: Role of Design, Microstructure, and Malseating.

BACKGROUND: Modular dual mobility (DM) bearings have a junction between a cobalt chrome alloy (CoCrMo) liner and titanium shell, and the risk of tribocorrosion at this interface remains a concern. The purpose of this study was to determine whether liner malseating and liner designs are associated with taper tribocorrosion. METHODS: We evaluated 28 retrieved modular DM implants with a mean in situ duration of 14.6 months (range, 1 to 83). There were 2 manufacturers included (12 and 16 liners, respectively). Liners were considered malseated if a distinct divergence between the liner and shell was present on postoperative radiographs. Tribocorrosion was analyzed qualitatively with the modified Goldberg Score and quantitatively with an optical coordinate-measuring machine. An acetabular shell per manufacturer was sectioned for metallographic analysis. RESULTS: There were 6 implants (22%) that had severe grade 4 corrosion, 6 (22%) had moderate grade 3, 11 (41%) had mild grade 2, and 5 (18.5%) had grade 1 or no visible corrosion. The average volumetric material loss at the taper was 0.086 ± 0.19 mm3. There were 7 liners (25%) that had radiographic evidence of malseating, and all were of a single design (P = .01). The 2 liner designs were fundamentally different from one another with respect to the cobalt chrome alloy type, taper surface finish, and shape deviations. Malseating was an independent risk factor for increased volumetric material loss (P = .017). CONCLUSIONS: DM tribocorrosion with quantifiable material loss occurred more commonly in malseated liners. Specific design characteristics may make liners more prone to malseating, and the interplay between seating mechanics, liner characteristics, and patient factors likely contributes to the shell/liner tribocorrosion environment. LEVEL OF EVIDENCE: Level III.

Three Differing Methods of Treating Intraoperative Nondisplaced Calcar Fractures Demonstrate Similar Radiographic Stem Subsidence.

BACKGROUND: Several management strategies have been described to treat intraoperative calcar fractures during total hip arthroplasty (THA), including retaining the primary implant and utilizing cerclage cables (CCs) or switching the implant to one that bypasses the fracture and achieves diaphyseal fixation. However, the radiographic and clinical outcomes of these differing strategies have never been described and compared. METHODS: We retrospectively identified 50 patients who sustained an intraoperative calcar fracture out of 9,129 primary total hip arthroplasties (0.55%) performed by one of three surgeons between 2008 and 2022. Each of the three surgeons consistently employed a distinct strategy for the management of these fractures: retention of the primary metaphyseal-engaging implant and placement of CCs; exchange to a modular, tapered-fluted stem (MTF); or exchange to a fully-coated, diaphyseal-engaging stem (FC). Stem subsidence was then evaluated on standing anteroposterior pelvis radiographs at three months and one year postoperatively. Postoperative medical and surgical complication rates were evaluated. RESULTS: A total of fifteen patients were treated with CC, 15 with MTF, and 20 with FC. At three-month follow-up, mean stem subsidence was 0.43 ± 0.08 mm, 1.47 ± 0.36 mm, and 0.68 ± 0.39 mm for CC, MTF, and FC cohorts, respectively (P = .323). At one-year, mean stem subsidence was 0.70 ± 0.08 mm, 1.74 ± 0.69 mm, and 1.88 ± 0.90 mm for the CC, MTF, and FC cohorts, respectively (P = .485). Medical complications included 2 venous thromboembolic events (4%) within 90 days of surgery. There were 6 reoperations (12%); 3 (6%) for acute periprosthetic joint infection (all within the FC cohort); 2 (4%) for postoperative periprosthetic fractures (one fracture distal to the stem in the FC cohort and one fracture at the level of the stem in the MTF cohort), and 1 (2%) closed reduction for instability (within the CC cohort). CONCLUSIONS: The three described methods of managing intraoperative nondisplaced calcar fractures demonstrated little radiographic stem subsidence; however, the risk of reoperation was much higher than expected.

Body Mass Index Does Not Drive the Risk for Early Postoperative Instability After Total Hip Arthroplasty: A Matched Cohort Analysis.

BACKGROUND: Instability remains the leading cause of revision following total hip arthroplasty (THA). The objective of the present investigation was to determine whether an elevated body mass index (BMI) is associated with an increased risk of instability after primary THA. METHODS: An administrative claims database was queried for patients undergoing elective, primary THA for osteoarthritis between 2010 and 2022. Patients who underwent THA for a femoral neck fracture were excluded. Patients who had an elevated BMI were grouped into the following cohorts: 25 to 29.9 (n = 2,313), 30 to 34.9 (n = 2,230), 35 to 39.9 (n = 1,852), 40 to 44.9 (n = 1,450), 45 to 49.9 (n = 752), and 50 to 59.9 (n = 334). Patients were matched 1:1 based on age, sex, and Elixhauser Comorbidity Index, as well as a history of spinal fusion, neurodegenerative disorders, and alcohol abuse, to controls with a normal BMI (20 to 24.9). A multivariate logistic regression controlling for age, sex, Elixhauser Comorbidity Index, and additional risk factors for dislocation was used to evaluate dislocation rates at 30 days, 90 days, 6 months, 1 year, and 2 years. Rates of revision for instability were similarly compared at 1 year and 2 years postoperatively. RESULTS: No significant differences in dislocation rate were observed between control patients and each of the evaluated BMI classes at all evaluated postoperative intervals (all P values > .05). Similarly, the risk of revision for instability was comparable between the normal weight cohort and each evaluated BMI class at 1 year and 2 years postoperatively (all P values > .05). CONCLUSIONS: Controlling for comorbidities and known risk factors for instability, the present analysis demonstrated no difference in rates of dislocation or revision for instability between normal-weight patients and those in higher BMI classes.

The Chitranjan S. Ranawat Award: Manipulation Under Anesthesia to Treat Postoperative Stiffness After Total Knee Arthroplasty: A Multicenter Randomized Clinical Trial.

BACKGROUND: Manipulation under anesthesia (MUA) occurs in 4% of patients after total knee arthroplasty (TKA). Anti-inflammatory medications may target arthrofibrosis pathogenesis, but the data are limited. This multicenter randomized clinical trial investigated the effect of adjuvant anti-inflammatory medications with MUA and physical therapy on range of motion (ROM) and outcomes. METHODS: There were 124 patients (124 TKAs) who developed stiffness after primary TKA for osteoarthritis enrolled across 15 institutions. All received MUA when ROM was < 90° at 4 to 12 weeks postoperatively. Randomization proceeded via a permuted block design. Controls received MUA and physical therapy, while the treatment group also received one dose of pre-MUA intravenous dexamethasone (8 mg) and 14 days of oral celecoxib (200 mg). The ROM and clinical outcomes were assessed at 6 weeks and 1 year. This trial was registered with ClinicalTrials.gov. RESULTS: The ROM significantly improved a mean of 46° from a pre-MUA ROM of 72 to 118° immediately after MUA (P < .001). The ROM was similar between the treatment and control groups at 6 weeks following MUA (101 versus 99°, respectively; P = .35) and at one year following MUA (108 versus 108°, respectively; P = .98). Clinical outcomes were similar at both end points. CONCLUSIONS: In this multicenter randomized clinical trial, the addition of intravenous dexamethasone and a short course of oral celecoxib after MUA did not improve ROM or outcomes. However, MUA provided a mean ROM improvement of 46° immediately, 28° at 6 weeks, and 37° at 1 year. Further investigation in regards to dosing, duration, and route of administration of anti-inflammatory medications remains warranted. LEVEL OF EVIDENCE: Level 1, RCT.

Advanced Concepts in Outpatient Joint Arthroplasty.

As the adoption and utilization of outpatient total joint arthroplasty continues to grow, key developments have enabled surgeons to safely and effectively perform these surgeries while increasing patient satisfaction and operating room efficiency. Here, the authors will discuss the evidence-based principles that have guided this paradigm shift in joint arthroplasty surgery, as well as practical methods for selecting appropriate candidates and optimizing perioperative care. There will be 5 core efficiency principles reviewed that can be used to improve organizational management, streamline workflow, and overcome barriers in the ambulatory surgery center. Finally, future directions in outpatient surgery at the ASC, including the merits of implementing robot assistance and computer navigation, as well as expanding indications for revision surgeries, will be debated.

Chat Generative Pretrained Transformer (ChatGPT) and Bard: Artificial Intelligence Does not yet Provide Clinically Supported Answers for Hip and Knee Osteoarthritis.

BACKGROUND: Advancements in artificial intelligence (AI) have led to the creation of large language models (LLMs), such as Chat Generative Pretrained Transformer (ChatGPT) and Bard, that analyze online resources to synthesize responses to user queries. Despite their popularity, the accuracy of LLM responses to medical questions remains unknown. This study aimed to compare the responses of ChatGPT and Bard regarding treatments for hip and knee osteoarthritis with the American Academy of Orthopaedic Surgeons (AAOS) Evidence-Based Clinical Practice Guidelines (CPGs) recommendations. METHODS: Both ChatGPT (Open AI) and Bard (Google) were queried regarding 20 treatments (10 for hip and 10 for knee osteoarthritis) from the AAOS CPGs. Responses were classified by 2 reviewers as being in "Concordance," "Discordance," or "No Concordance" with AAOS CPGs. A Cohen's Kappa coefficient was used to assess inter-rater reliability, and Chi-squared analyses were used to compare responses between LLMs. RESULTS: Overall, ChatGPT and Bard provided responses that were concordant with the AAOS CPGs for 16 (80%) and 12 (60%) treatments, respectively. Notably, ChatGPT and Bard encouraged the use of non-recommended treatments in 30% and 60% of queries, respectively. There were no differences in performance when evaluating by joint or by recommended versus non-recommended treatments. Studies were referenced in 6 (30%) of the Bard responses and none (0%) of the ChatGPT responses. Of the 6 Bard responses, studies could only be identified for 1 (16.7%). Of the remaining, 2 (33.3%) responses cited studies in journals that did not exist, 2 (33.3%) cited studies that could not be found with the information given, and 1 (16.7%) provided links to unrelated studies. CONCLUSIONS: Both ChatGPT and Bard do not consistently provide responses that align with the AAOS CPGs. Consequently, physicians and patients should temper expectations on the guidance AI platforms can currently provide.

Bisphosphonate Use May be Associated With an Increased Risk of Periprosthetic Hip Fracture.

BACKGROUND: Osteoporosis is common among patients undergoing primary total hip arthroplasty (THA). This study aimed to evaluate the effect of bisphosphonate treatment on osteoporotic patients undergoing primary THA. METHODS: Using a national database, 30,137 patients who had osteoporosis before primary elective THA were identified during 2010 to 2020. Patients undergoing nonelective THA and those using corticosteroids or other medications for osteoporosis were excluded. Bisphosphonate users and bisphosphonate naïve patients were matched 1:1 based on age, sex, Elixhauser comorbidity index, and a history of obesity, rheumatoid arthritis, tobacco use, and alcohol abuse. Kaplan-Meier and multivariate analyses were used to compare 2-year outcomes between groups. RESULTS: Among matched cohorts of 9,844 patients undergoing primary THA, bisphosphonate use was associated with a significantly higher 2-year rate of periprosthetic fracture (odds ratio 1.29, 95% confidence interval 1.04 to 1.61, P = .022). There was a trend toward increased risk of any revision with bisphosphonate use (odds ratio 1.19, confidence interval 1.00 to 1.41, P = .056). Rates of infection, aseptic loosening, dislocation, and mortality were not statistically different between bisphosphonate users and bisphosphonate-naïve patients. CONCLUSION: In osteoporotic patients, bisphosphonate use before primary THA is an independent risk factor for periprosthetic fracture. Additional longer-term data are needed to determine the underlying mechanism for this association and identify preventative measures.

Strikingly High Rates of Periprosthetic Joint Infection Following Revision Surgery for Periprosthetic Fractures Regardless of Surgery Timing.

BACKGROUND: Periprosthetic fractures following total hip arthroplasty (THA) often occur in the early postoperative period. Recent data has indicated that early revisions are associated with higher complication rates, particularly periprosthetic joint infection (PJI). The purpose of this study was to assess the effect of timing of periprosthetic fracture surgery on complication rates. We hypothesized that complication rates would be significantly higher in revision surgeries performed within 3 months of the index THA. METHODS: The Medicare Part A claims database was queried from 2010 to 2017 to identify patients who underwent surgery for a periprosthetic fracture following primary THA. Patients were divided based on time between index and revision surgeries: <1, 1 to 2, 2 to 3, 3 to 6, 6 to 9, 9 to 12, and >12 months. Complication rates were compared between groups using multivariate analyses to adjust for demographics, comorbidities, and types of revision surgery. RESULTS: Of 492,340 THAs identified, 4,368 (0.9%) had a subsequent periprosthetic fracture requiring surgery: 1,725 (39.4%) at <1 month, 693 (15.9%) at 1 to 2 months, 202 (4.6%) at 2 to 3 months, 250 (5.7%) at 3 to 6 months, 134 (3.1%) at 6 to 9 months, 85 (19.4%) at 9 to12 months, and 1,279 (29.3%) at >12 months. The risk of PJI was 11.0% in the <1 month group, 11.1% at 1 to 2 months, 7.9% at 2 to 3 months, 6.8% at 3 to 6 months, 8.2% at 6 to 9 months, 9.4% at 9 to 12 months, and 8.5% at >12 months (P = .12). Adjusting for confounding factors, risk of PJI following periprosthetic fracture surgery was similar regardless of timing (P > .05). Rates of subsequent dislocation and aseptic loosening were also similar regardless of timing. CONCLUSIONS: The risk of PJI following repeat surgery for a periprosthetic fracture was strikingly high regardless of timing (6.8 to 11.1%), underscoring the high-risk of complications.

Hypoalbuminemia Increases Mortality after Two-Stage Revision Total Joint Arthroplasty.

Objectives: This study aimed to evaluate the effect of hypoalbuminemia on failure rates and mortality after a two-stage revision for PJI. Methods: 199 Patients (130 knees and 69 hips) with a mean age of 64.7 ± 10.7 years who underwent a two-stage exchange were retrospectively reviewed at a mean of 51.2 ± 39.7 months. Failure of treatment was defined as any revision within the follow-up period, failure to undergo reimplantation, or death within one year of initiating treatment. Results: There were 71 failures (35.7%), including 38 septic failures (19.1%). We found no differences between successful revisions and failures regarding hypoalbuminemia (43% vs. 42% prior to stage 1, P=1 and 32% vs. 29% prior to stage 2, P=0.856). There were also no differences in hypoalbuminemia rates between septic failures and the rest of the cohort (42% vs. 43% prior to stage 1, P=1.0 and 34% vs. 30% prior to stage 2, P=0.674). Hypoalbuminemia prior to stage 2 was a significant predictor of mortality based on multivariate analysis (odds ratio 5.40, CI 1.19-24.54, P=0.029). Hypoalbuminemia was independently associated with a greater length of stay by 2.2 days after stage 1 (P=0.002) and by 1.0 days after the second stage reimplantation (P=0.004). Conclusion: Preoperative hypoalbuminemia is a significant predictor of mortality and increased length of stay following two-stage revision but is not a predictor of failure of PJI treatment. Further study is required to understand if hypoalbuminemia is a modifiable risk factor or a marker for poor outcomes.

The Microbiome of Osteoarthritic Hip and Knee Joints: A Prospective Multicenter Investigation.

BACKGROUND: Recent advances in high-throughput DNA sequencing technologies have made it possible to characterize the microbial profile in anatomical sites previously assumed to be sterile. We used this approach to explore the microbial composition within joints of osteoarthritic patients. METHODS: This prospective multicenter study recruited 113 patients undergoing hip or knee arthroplasty between 2017 and 2019. Demographics and prior intra-articular injections were noted. Matched synovial fluid, tissue, and swab specimens were obtained and shipped to a centralized laboratory for testing. Following DNA extraction, microbial 16S-rRNA sequencing was performed. RESULTS: Comparisons of paired specimens indicated that each was a comparable measure for microbiological sampling of the joint. Swab specimens were modestly different in bacterial composition from synovial fluid and tissue. The 5 most abundant genera were Escherichia, Cutibacterium, Staphylococcus, Acinetobacter, and Pseudomonas. Although sample size varied, the hospital of origin explained a significant portion (18.5%) of the variance in the microbial composition of the joint, and corticosteroid injection within 6 months before arthroplasty was associated with elevated abundance of several lineages. CONCLUSIONS: The findings revealed that prior intra-articular injection and the operative hospital environment may influence the microbial composition of the joint. Furthermore, the most common species observed in this study were not among the most common in previous skin microbiome studies, suggesting that the microbial profiles detected are not likely explained solely by skin contamination. Further research is needed to determine the relationship between the hospital and a "closed" microbiome environment. These findings contribute to establishing the baseline microbial signal and identifying contributing variables in the osteoarthritic joint, which will be valuable as a comparator in the contexts of infection and long-term arthroplasty success. LEVEL OF EVIDENCE: Diagnostic Level II. See Instructions for Authors for a complete description of levels of evidence.

High rate of failure after revision extensor mechanism allograft reconstruction.

BACKGROUND: Patients who fail initial extensor mechanism allograft (EMA) reconstruction for extensor mechanism disruption after total knee arthroplasty (TKA) are left with few options. This study evaluated outcomes in patients that underwent revision EMA reconstruction following a failed EMA. METHOD: Ten patients that underwent revision EMA for failed index EMA with minimum 1-year follow-up were retrospectively reviewed. Patients receiving fresh-frozen EMA (quadriceps tendon, patella, patellar tendon, and tibial tubercle) at index and revision EMA were included. The primary outcome was EMA failure defined as revision surgery, extensor lag > 30°, or Knee Society Score (KSS) < 60 at last follow-up. Descriptive statistics were performed, with p < 0.05. RESULTS: Mean extensor lag improved from 55.6°±26.7° pre-revision to 32.8°±29.6° (p = 0.13) at mean follow-up of 43.8 months (range, 12-124 months). Mean KSS improved from 41.0 ±â€¯9.5 pre-revision to 73.4 ±â€¯14.5 at last follow-up (p < 0.001). All patients required assistive devices for ambulation at final follow-up: one (10.0%) required a wheelchair, five (50.0%) required a walker, and four (40.0%) required a cane. Seven (70.0%) patients experienced EMA failure at a mean of 33.6 months (range, 2-124) following revision EMA: three (30.0%) were revised for periprosthetic joint infection (one of which also had extensor lag > 30°), three (30.0%) additional patients had extensor lag > 30°, and one (10.0%) patient had KSS < 60 (this patient developed PJI and was treated nonoperatively with chronic antibiotic suppression). CONCLUSIONS: Revision EMA reconstruction fails at a high rate despite leading to improvements in KSS. Further research is needed to develop effective prevention and treatment strategies for failure after initial EMA reconstruction.

Invasive Gastrointestinal Endoscopy Following Total Joint Arthroplasty Increases the Risk for Periprosthetic Joint Infection.

BACKGROUND: The safety of postoperative colonoscopy and endoscopy following total joint arthroplasty (TJA) remains largely unknown. The objective of this study was to characterize the effect of gastrointestinal endoscopic procedures after TJA on the risk of postoperative periprosthetic joint infection (PJI). METHODS: Using a large national database, patients who underwent an endoscopic procedure (colonoscopy or esophagogastroduodenoscopy (EGD)) within 12 months after primary TJA were identified and matched in a 1:1 fashion based on procedure (primary total knee arthroplasty (TKA) versus total hip arthroplasty (THA)), age, sex, Charlson Comorbidity Index (CCI), and smoking status with patients who did not undergo endoscopy. A total of 142,055 patients who underwent endoscopy within 12 months following TJA (96,804 TKAs and 45,251 THAs) were identified and matched. The impact of timing of endoscopy relative to TJA on postoperative outcomes was assessed. Preoperative comorbidity profiles and 1-year complications were compared. Statistical analyses included Chi-squared tests and multivariate logistic regressions with outcomes considered significant at P < .05. RESULTS: Multivariate analyses revealed that endoscopy within 2 months following TKA and 1 month of THA was associated with a significantly increased odds of periprosthetic joint infection (odds ratio (OR): 1.29 [1.08-1.53]; P = .004; OR: 1.41 [1.01-1.90]; P = .033, respectively). Patients who underwent endoscopy greater than 2 months from the timing of their TKA and 1 month from THA were not at significantly greater risk of developing PJI. CONCLUSION: These data suggest that invasive endoscopic procedures should be delayed if possible by at least 2 months following TKA and 1 month following THA to minimize the risk of PJI.