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.

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.

INTRODUCTION: 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- 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- and non-fellowship-trained surgeons had propensity scores matched based on age, sex, comorbidity index, and diagnosis. The five-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 non-aspirin anticoagulants (21.4 versus 32.0%, P < 0.001). Fellowship-training was associated with lower dislocation rates (9.9 versus 14.2%, P = 0.011), fewer postoperative infections, and fewer periprosthetic fractures and re-revisions (15.2 versus 21.3%, P < 0.001). Head-liner exchange for infection performed by fellowship-trained surgeons was associated with lower odds of failure (31.2 versus 45.7%, odds ratio (OR) 0.76, 95% confidence interval (CI) 0.62 to 0.91, P < 0.001). CONCLUSIONS: Revision THA 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.

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.

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.

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.

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.

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.

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.

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.

Hot Topics and Current Controversies in Total Knee Arthroplasty.

Total knee arthroplasty continues to evolve. It is important to review some of the current controversies and hot topics in arthroplasty. Optimal knee alignment strategy is now just a matter of debate. Mechanical, kinematic, and functional alignment and the role of robotics in achieving optimum alignment are important topics, along with fixation and outpatient knee arthroplasty.

Intra-articular corticosteroid injections are associated with a dose-dependent risk of total knee arthroplasty at 5 years.

PURPOSE: Intra-articular corticosteroid injections (CSI) are used commonly for the non-operative management of patients with knee pain. Recent literature has raised concern for chondrotoxicity of CSI. The purpose of the present study is to evaluate for any dose-dependent association between CSI in non-osteoarthritic knees and subsequent total knee arthroplasty (TKA). METHODS: The Pearl Diver database identified patients with a diagnosis of knee pain without concomitant osteoarthritis who were administered CSI over a 2-year period. Patients were compared to matched and unmatched cohorts. The primary endpoint was the incidence of TKA at 5 years. Multivariable regression analysis was used to assess CSI quantity as an independent risk factor. RESULTS: 49,443 of 986,162 (5.0%) Patients diagnosed with knee pain without concomitant knee osteoarthritis who received at least one CSI were identified. At 5 years, there was a higher incidence of TKA in the matched injection cohort relative to the non-injection matched cohort (0.26 vs 0.13%; p < 0.001) and unmatched cohort (0.26 vs. 0.10%, p < 0.001). The quantity of CSI corresponded with an increased probability of TKA at 5 years; one injection: 0.22% (OR 1.23, 95% CI [0.87-1.74], p = 0.236); two injections: 0.39% (OR 1.98 CI [1.06-3.67], p = 0.03, three or more injections: 0.49% (OR 3.22 CI [1.60-6.48], p = 0.001). The average time to TKA after one CSI was 3.03 ± 2.29 years. This time was nearly halved with three CSI (1.78 ± 0.80 years, p < 0.001). CONCLUSIONS: Intra-articular corticosteroid injections in patients without knee osteoarthritis at the time of injection are associated with a dose-dependent risk of TKA at 5 years. CSI may not be as benign of a treatment modality as previously thought.

Elective Joint Arthroplasty Should be Delayed by One Month After COVID-19 Infection to Prevent Postoperative Complications.

BACKGROUND: It remains unclear whether a history of recent COVID-19 infection affects the outcomes and risks of complications of total joint arthroplasty (TJA). The purpose of this study was to compare the outcomes of TJA in patients who have and have not had a recent COVID-19 infection. METHODS: A large national database was queried for patients undergoing total hip and total knee arthroplasty. Patients who had a diagnosis of COVID-19 within 90-days preoperatively were matched to patients who did not have a history of COVID-19 based on age, sex, Charlson Comorbidity Index, and procedure. A total of 31,453 patients undergoing TJA were identified, of which 616 (2.0%) had a preoperative diagnosis of COVID-19. Of these, 281 COVID-19 positive patients were matched with 281 patients who did not have COVID-19. The 90-day complications were compared between patients who did and did not have a diagnosis of COVID-19 at 1, 2, and 3 months preoperatively. Multivariate analyses were used to further control for potential confounders. RESULTS: Multivariate analysis of the matched cohorts showed that COVID-19 infection within 1 month prior to TJA was associated with an increased rate of postoperative deep vein thrombosis (odds ratio [OR]: 6.50, 95% confidence interval: 1.48-28.45, P = .010) and venous thromboembolic events (odds ratio: 8.32, confidence interval: 2.12-34.84, P = .002). COVID-19 infection within 2 and 3 months prior to TJA did not significantly affect outcomes. CONCLUSION: COVID-19 infection within 1 month prior to TJA significantly increases the risk of postoperative thromboembolic events; however, complication rates returned to baseline after that time point. Surgeons should consider delaying elective total hip arthroplasty and total knee arthroplasty until 1 month after a COVID-19 infection.

Cementless Total Knee Arthroplasty is Associated With Early Aseptic Loosening in a Large National Database.

BACKGROUND: Despite excellent longevity demonstrated in institutional studies, outcomes after cementless total knee arthroplasty (TKA) on a population level remain unknown. This study compares 2-year outcomes between cemented and cementless TKA using a large national database. METHODS: A large national database was used to identify 294,485 patients undergoing primary TKA from January 2015 to December 2018. Patients who had osteoporosis or inflammatory arthritis were excluded. Cementless and cemented TKA patients were matched one-to-one based on age, Elixhauser Comorbidity Index, sex, and year yielding matched cohorts of 10,580 patients. Outcomes at 90 days, 1 year, and 2 years postoperatively were compared between groups, and Kaplan-Meier analysis was used to evaluate implant survival rates. RESULTS: At 1 year postoperatively, cementless TKA was associated with an increased rate of any reoperation (odds ratio [OR] 1.47, 95% confidence interval [CI] 1.12-1.92, P = .005) compared to cemented TKA. At 2 years postoperatively, there was an increased risk of revision for aseptic loosening (OR 2.34, CI 1.47-3.85, P < .001) and any reoperation (OR 1.29, CI 1.04-1.59, P = .019) after cementless TKA. Two-year revision rates for infection, fracture, and patella resurfacing were similar between cohorts. CONCLUSION: In this large national database, cementless fixation is an independent risk factor for aseptic loosening requiring revision and any reoperation within 2 years after primary TKA.

Contralateral Total Hip Arthroplasty Staged Within Six Weeks Increases the Risk of Adverse Events Compared to Unilateral Surgery.

BACKGROUND: The ideal timing for bilateral total hip arthroplasty (THA) remains controversial. This study compared 90-day outcomes after simultaneous bilateral THA and contralateral surgery in staged bilateral THA to a matched cohort of unilateral procedures. METHODS: Patients undergoing primary, elective THA during 2015 to 2020 were reviewed in a national database. Of the 273,281 patients identified, 39,905 (14.6%) were bilateral. Patients were divided into cohorts of unilateral THA, simultaneous bilateral THA, and staged bilateral THA at 1 to 14 days, 15 to 42 days, 43 to 90 days, and 91 to 365 days. Bilateral THA cohorts were matched with unilateral THA patients based on demographics and comorbidities. Ninety-day outcomes after the second THA were compared between matched groups. RESULTS: Simultaneous bilateral THA resulted in higher rates of transfusion (odds ratio [OR] 4.43, 95% confidence interval 2.31-2.63, P < .001), readmission (OR 2.60, 2.01-3.39, P < .001), and any complication (OR 1.86, 1.55-2.24, P < .001) compared to unilateral THA. Contralateral THA staged at 1 to 14 days increased the risk of readmission (OR 1.83, 1.49-2.24, P < .001) and any complication (OR 1.45, 1.26-1.66, P < .001) relative to unilateral THA. Contralateral THA staged at 15 to 42 days increased the risk of periprosthetic joint infection (OR 3.15, 1.98-5.19, P < .001), readmission (OR 1.92, 1.55-2.39, P < .001), and any complication (OR 1.70, 1.46-1.97, P < .001). Contralateral THA staged beyond 42 days resulted in similar or decreased rates of adverse events relative to unilateral THA. CONCLUSIONS: Bilateral THA should be staged a minimum of 6 weeks apart in appropriately selected patients to avoid an increased risk of adverse events after the second THA compared to unilateral THA.

Vitamin D3 Supplementation Prior to Total Knee Arthroplasty: A Randomized Controlled Trial.

BACKGROUND: The purpose of this randomized controlled trial was to determine if a one-time dose of vitamin D3 prior to total knee arthroplasty improves function and patient-reported outcomes, while decreasing complications. METHODS: One hundred seven patients undergoing primary total knee arthroplasty were randomized to receive 50,000 international units vitamin D3 (57 patients) or placebo (50 patients) on the morning of surgery. Power analysis determined 45 patients were required in each cohort to detect a minimal clinically important difference of 6 points in the functional component of the 2011 version of the Knee Society Score (KSS), assuming an alpha of 0.05 and power of 80%. KSS and a Timed Up and Go Test (TUGT) were measured preoperatively and at 3 and 6 weeks postoperatively. RESULTS: There was no difference in improvement of KSS at 3 weeks (+4.8 points vitamin D3 versus +3.0 points placebo; P = .6) or 6 weeks (+14.5 points vitamin D3 versus +12.4 points placebo; P = .5) from baseline. There was no difference in change in TUGT at 3 weeks (+1.2 seconds vitamin D3 versus +0.6 seconds placebo; P = .6) or 6 weeks (-0.3 seconds vitamin D3 versus -0.9 seconds placebo; P = .6) from baseline. There were 4 complications in the placebo cohort within the first 90 days postoperatively and 5 complications in the vitamin D3 cohort (P = 1.0). CONCLUSION: Supplementation with 50,000 international units vitamin D3 on the day of surgery failed to demonstrate statistical significant differences in functional KSS, TUGT times, or complications in the early postoperative period compared to placebo. LEVEL OF EVIDENCE: Level I, therapeutic study.

Ultrasound-Guided Iliopsoas Bursal Injections for Management of Iliopsoas Bursitis After Total Hip Arthroplasty.

BACKGROUND: Iliopsoas tendonitis can cause persistent pain after total hip arthroplasty (THA). Nonoperative management of iliopsoas tendonitis includes anti-inflammatory drugs and image-guided corticosteroid injections. This study evaluated the efficacy of ultrasound-guided corticosteroid injections (US-CSIs) for iliopsoas tendonitis following THA. METHODS: We retrospectively reviewed 42 patients who received an US-CSI for iliopsoas tendonitis after primary THA between 2009 and 2020 at a single institution. Outcomes including reoperation, groin pain at last follow-up, additional intrabursal injection, and Harris Hip Score (HHS) were evaluated at a minimum of 1 year. Cross-table lateral radiographs (36 patients) or computed tomography scans (6 patients) were reviewed to determine if anterior cup overhang was present, indicating a mechanical etiology of iliopsoas tendonitis. Descriptive statistics and univariate comparison of HHS preinjection and postinjection were performed, with alpha < 0.05. RESULTS: Among the 22 patients who did not have cup overhang, four (18.2%) had persistent groin pain at mean follow-up of 40 months (range, 14-94) after US-CSI. Three patients had a second injection; none had groin pain at most recent follow-up. No patients required acetabular revision. Mean HHS improved from 74 points (range, 52-94 points) to 91 points (range, 76-100 points; P < .001) at last follow-up. Among the 20 patients who had anterior cup overhang, five underwent acetabular revision after only temporary pain relief from injection. Groin pain was resolved in all revised patients at mean follow-up of 43 months (range, 12-60) after revision. Of the remaining 15 patients, five had persistent groin pain at mean follow-up of 35 months (range, 12-83). Mean HHS improved from 69 points (range, 50-96 points) preinjection to 81 (range, 56-98 points; P = .007) at last follow-up. CONCLUSION: Resolution of groin pain was demonstrated in 78.6% of patients in the cohort; however, those who did not have acetabular overhang had higher rates of success. The overall revision rate was 11.9%. US-CSI appears to be safe and effective in the diagnosis and treatment of iliopsoas tendonitis following primary THA. LEVEL OF EVIDENCE: Level IV, Therapeutic Study.

Over Half of All Medicare Total Knee Arthroplasty Patients Are Now Classified as an Outpatient-Three-Year Impact of the Removal From the Inpatient-Only List.

BACKGROUND: In 2018, Centers for Medicare & Medicaid Services removed total knee arthroplasty (TKA) from its inpatient-only list, triggering many unintended consequences. The purpose of this study was to determine how the impact of TKA removal affected the number of outpatient TKA patients, which patients were being labeled outpatient, and how outpatient classification affected discharge location and readmission rates. METHODS: Using a large administrative claims database, we reviewed a consecutive series of 216,365 primary TKA Medicare patients from 2015 to 2020. Patients who had an inpatient status (n = 63,356) were compared to patients who had an outpatient status (n = 38,510) from 2018 to 2020 based on demographics, comorbidities, discharge dispositions, and readmissions. RESULTS: In 2015, only 1.8% of TKA patients were designated as outpatients, but by 2020, 57.2% of Medicare TKA patients were classified as outpatients. A majority of patients (72%) who had an outpatient designation remained in the hospital for >24 hours (average length of stay was 2.7 days). Patients who had an outpatient status were discharged to skilled nursing facilities more frequently than patients who had an inpatient status (3.1 versus 2.0%, P < .001) with increased emergency visits (5.1 versus 3.9%, P < .001) and 90-day readmissions (2.2 versus 0.9%, P < .001). CONCLUSION: Over half of all Medicare TKA patients are being classified as outpatients 3 years following the policy to remove TKA from the inpatient-only list. Patients designated as outpatients had higher readmissions than those designated as inpatients. This policy should be re-evaluated in the context of failure to demonstrate safer discharge of Medicare patients who undergo TKA.

Outpatient Total Knee Arthroplasty Shows Decreasing Complication Burden From 2010 to 2020.

BACKGROUND: The number of total knee arthroplasties (TKAs) performed on an outpatient basis continues to increase. The purpose of this study was to compare complication rates over the last decade to evaluate trends in the safety of outpatient TKA. METHODS: Patients who underwent TKA from 2010 to 2020 from a large administrative claims database were retrospectively identified and stratified based on the year of surgery. Propensity-score matching was performed to match patients who were discharged within 24 hours of surgery to inpatients based on age, sex, comorbidity index, and year of surgery. Linear regression analyses were used to compare trends from 2010 to 2020. The 90-day adverse events in the early cohort (2010-2012) were compared to those in the late cohort (2018-2020) using multivariable regression analyses. Of the 547,137 patients in the sample, 28,951 outpatients (5.3%) were propensity matched to inpatients. RESULTS: The incidence of outpatient TKA increased from 2010 to 2018 (1.9 versus 13.8%, P < .001). Despite a similar complication rate early (24.1 versus 22.6%, P = .164), outpatient TKA had fewer complications at the end of the study period (13.7 versus 16.7%, P < .001). Multivariate analyses demonstrated that the risk of any complication after outpatient TKA was lower than inpatient from 2018 to 2020 (odds ratio, 0.78; 95% confidence interval, 0.71-0.84). CONCLUSIONS: Complications in both cohorts declined dramatically suggesting improvements in quality of care over time, with the greatest decline in patients undergoing outpatient surgery. These results suggest that outpatient TKA today is not higher risk for the patient than inpatient TKA. LEVEL OF EVIDENCE: Level III.

Dual-Mobility versus Large Femoral Heads in Revision Total Hip Arthroplasty: Interim Analysis of a Randomized Controlled Trial.

BACKGROUND: This multicenter randomized controlled trial evaluated if dual-mobility bearings (DM) lower the risk of dislocation compared to large femoral heads (≥36 mm) for patients undergoing revision total hip arthroplasty (THA) via a posterior approach. METHODS: A total of 146 patients were randomized to a DM (n = 76; 46 mm median effective head size, range 36 to 59 mm) or a large femoral head (n = 70; twenty-five 36 mm heads [35.7%], forty-one 40 mm heads [58.6%], and four 44 mm heads [5.7%]). There were 71 single-component revisions (48.6%), 39 both-component revisions (26.7%), 24 reimplantations of THA after 2-stage revision (16.4%), seven isolated head and liner exchanges (4.8%), four conversions of hemiarthroplasty (2.7%), and 1 revision of a hip resurfacing (0.7%). Power analysis determined that 161 patients were required in each group to lower the dislocation rate from 8.4 to 2.2% (power = 0.8, alpha = 0.05). RESULTS: At a mean of 18.2 months (range, 1.4 to 48.2), there were three dislocations in the large femoral head group compared to two in the DM cohort (4.3 versus 2.6%; P = .67). One patient in the large head group and none in the DM group were successfully treated with closed reduction without subsequent revision. CONCLUSION: Interim analysis of this randomized controlled trial found no difference in the risk of dislocation between DM and large femoral heads in revision THA, although the rate of dislocation was lower than anticipated and continued follow-up is needed.