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.

Early Prosthetic Hip Dislocation: Does the Timing of the Dislocation Matter?

INTRODUCTION: Early dislocation following total hip arthroplasty (THA) is a common reason for revision. The purpose of this study was to determine if the acuity of the dislocation episode affects the risk of revision surgery. METHODS: A retrospective review of a national, all-payer administrative database comprised of claims from 2010 to 2020 was used to identify patients who had a prosthetic hip dislocation at various post-operative time intervals (0 to 7, 7 to 30, 30 to 60, and 60 to 90 days). Of the 45,352 primary unilateral THA patients who had sufficient follow-up, there were 2,878 dislocations within 90 days. Dislocators were matched 1:1 based on age, sex, and a comorbidity index with a control group (no dislocation). Demographics, surgical indications, comorbidities, ten-year revision rates, and complications were compared among cohorts. Multivariable logistic regression analysis was performed to identify risk factors for revision THA following early dislocation. RESULTS: Among matched cohorts, dislocation at any time interval was associated with significantly increased odds of subsequent 10-year revision (OR [odds ratio] = 25.60 to 33.4, P < 0.001). Acute dislocators within 7 days did not have an increased risk of all cause revisions at 10 years relative to other early dislocators. Revision for indication of instability decreased with time to first dislocation (< 7 days: 85.7% versus 60 to 90 days: 53.9%). Primary diagnoses of post traumatic arthritis (OR = 2.53 [1.84 to 3.49], P < 0.001), hip fracture (OR = 3.8 [2.53 to 5.72], P < 0.001), and osteonecrosis (OR = 1.75 [1.12 to 2.73], P = 0.010) were most commonly associated with revision surgery after an early dislocation. CONCLUSION: Dislocation within 90 days of total hip arthroplasty is associated with increased odds of subsequent revision. Early dislocation within 7 days of surgery has similar all cause revision-free survivorship, but an increased risk of a subsequent revision for instability when compared to patients who dislocated within 7 to 90 days.

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.

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.

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.

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.

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.

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.

The Cost-Effectiveness of Tibial Metaphyseal Cones in Revision Total Knee Arthroplasty.

BACKGROUND: The purpose of this study is to evaluate the cost-effectiveness of tibial cones in revision total knee arthroplasty. METHODS: A Markov model was used for cost-effectiveness analysis. The average cone price was obtained from Orthopedic Network News. The average cone aseptic loosening rate was determined by literature review. Hospitalization costs and baseline re-revision rates were calculated using the PearlDiver Database. RESULTS: The maximum cost-effective cone price varied from $3514 at age 40 to $648 at age 90, compared to the current average selling price of $4201. Cones became cost-effective with baseline aseptic loosening rates of 0.89% annually at age 40 to 4.38% annually at age 90, compared to the current average baseline loosening rate of 0.76% annually. CONCLUSION: For the average patient, tibial cones are not cost-effective, but may become so at lower prices, in younger patients, or in patients at substantially increased risk of aseptic loosening.

COVID-19 Infection After Total Joint Arthroplasty Is Associated With Increased Complications.

BACKGROUND: The impact of a postoperative diagnosis of COVID-19 in patients undergoing total joint arthroplasty (TJA) remains unknown. The objective of this study is to characterize the effect of COVID-19 infection following TJA on perioperative complication rates. METHODS: The Mariner database was queried for patients undergoing total hip and total knee arthroplasty from January 2018 to April 2020. TJA patients who were diagnosed with COVID-19 within 90 days postoperatively were matched in a 1:3 fashion based on age, gender, iron deficiency anemia, payer status, and Charlson Comorbidity Index with patients who were not diagnosed with COVID-19. Preoperative comorbidity profiles and complications within 3 months of surgery were compared. Statistical analysis included chi-squared tests and multivariate logistic regression with outcomes considered significant at P < .05. RESULTS: Of the 239 COVID-19 positive patients, 132 (55.2%) underwent total hip arthroplasty. On multivariate analysis, COVID-19 diagnosis was associated with increased odds of deep vein thrombosis (odds ratio [OR] 4.86, 95% confidence interval [CI] 2.10-11.81, P < .001), pulmonary embolism (OR 6.27, 95% CI 2.57-16.71, P < .001), and all complications (OR 3.36, 95% CI 2.47-4.59, P < .001). Incidence of deep vein thrombosis/pulmonary embolism was greater the closer in time the COVID-19 diagnosis was to the surgical procedure (10.24 times at 1 month, 7.87 times at 2 months, and 1.42 times at 3 months; P < .001). A similar relationship was observed with all complications. CONCLUSION: Postoperative COVID-19 infection is associated with higher rates of cardiopulmonary complications, thromboembolic disease, renal injury, and urinary tract infections in patients undergoing hip and knee arthroplasty. COVID-19 infection earlier in the postoperative period is associated with a higher risk of complications.

General Versus Neuraxial Anesthesia in Revision Surgery for Periprosthetic Joint Infection.

BACKGROUND: The purpose of this study was to compare neuraxial and general anesthesia in revision surgery for periprosthetic joint infection (PJI). METHODS: Patients undergoing revision arthroplasty for PJI were identified in the 2005-2019 American College of Surgeons National Surgical Quality Improvement Program databases. Thirty-day outcomes were compared between general and neuraxial anesthesia. Propensity-score matching and multivariate analysis were used to control patient and procedural variables. RESULTS: Neuraxial anesthesia was used in 1511 (16.8%) cases and general anesthesia in 7468 (83.2%) cases. Neuraxial anesthesia had a lower risk of any adverse event (odds ratio [OR] 0.70, P < .001), serious adverse events (OR 0.77, P < .001), and minor adverse events (OR 0.66, P < .001). Among 875 reoperations and 1351 readmissions, two had a diagnosis of intraspinal abscess, both occurring after general anesthesia. CONCLUSIONS: Neuraxial anesthesia was associated with a lower risk of adverse events when compared to general anesthesia in revision surgery for PJI.

Treatment modalities and outcomes following acetabular fractures in the elderly: a systematic review.

PURPOSE: The treatment of geriatric acetabular fractures remains controversial. Treatment options include nonoperative management, open reduction and internal fixation (ORIF), total hip arthroplasty (THA) with or without internal fixation, and closed reduction with percutaneous pinning (CRPP). There is currently no consensus on the optimal treatment strategy for geriatric patients with acetabular fractures. The purpose of this study is to compare adverse event rates, functional and radiographic outcomes, and intraoperative results between the various treatment modalities in order to help guide surgical decision making. METHODS: We performed a systematic review (registration number CRD42019124624) of observational and comparative studies including patients aged ≥ 55 with acetabular fractures. RESULTS: Thirty-eight studies including 3,928 patients with a mean age of 72.6 years (range 55-99 years) and a mean follow-up duration of 29.4 months met our eligibility criteria. The pooled mortality rate of all patients was 21.6% (95% confidence interval [CI] 20.9-22.4%) with a mean time to mortality of 12.6 months, and the pooled non-fatal complication rate was 24.7% (95% CI 23.9-25.5%). Patients treated with ORIF had a significantly higher non-fatal complication rate than those treated with ORIF + THA, THA alone, CRPP, or nonoperative management (odds ratios [ORs] 1.87, 2.24, 2.15, and 4.48, respectively; p < 0.01). Patients that underwent ORIF were significantly less likely to undergo subsequent THA than these treated with CRPP (OR 0.49, 95% CI 0.32-0.77) but were more likely to require THA than patients treated nonoperatively (OR 6.81, 95% CI 4.63-10.02). CONCLUSION: Elderly patients with acetabular fractures tend to have favorable functional outcomes but suffer from high rates of mortality and complications. In patients treated with internal or percutaneous fixation, there was a high rate of conversion to THA. When determining surgical treatment in this population, THA alone or concurrent with ORIF should be considered given the significantly lower rate of non-fatal complications and similar mortality rate. Nonoperative management remains a viable option and was associated with the lowest non-fatal complication rate. LEVEL OF EVIDENCE: This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

National Trends in Post-Acute Care Costs Following Total Knee Arthroplasty From 2007 to 2016.

BACKGROUND: Post-acute care continues to represent a target for cost savings with increasing popularity of value-based payment models in total knee arthroplasty (TKA). Rapid recovery and accelerated rehabilitation protocols have been successful in reducing costs at the institutional level, but national trends are less clear. This study aimed to determine if advancements in perioperative care led to a reduction in post-acute care costs and resource utilization following TKA. METHODS: We reviewed a consecutive series of 79,843 primary TKA patients from the Humana claims dataset from 2007 to 2016. Post-acute care costs included any claims within 90 days of surgery for subacute or inpatient rehabilitation, home health, outpatient or emergency visits, prescription medications, physical therapy, and readmissions. Demographics, episode-of-care and post-acute care costs, readmissions, and discharge disposition were compared. Controlling for demographics and comorbidities, multivariate regression analyses were performed to compare trends in discharge disposition and post-acute care costs. RESULTS: From 2007 to 2016, the average episode-of-care costs ($46,754 vs $31,856) and post-acute care costs per patient decreased ($20,224 vs $13,498). Rates of discharge to skilled nursing facilities (25.0% vs 22.5%) and inpatient rehabilitation also declined (12.4% vs 2.1%). Readmissions also decreased (8.1% vs 7.1%) saving an average of $324 per patient. When compared to 2007-2012, total costs declined most rapidly after 2013 primarily due to a $3516 (21%) decrease in post-acute spending. CONCLUSION: There has been a substantial decline in post-acute care costs and resource utilization following TKA, with the largest decrease occurring following the introduction of Medicare bundled payment models in 2013.

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.

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.

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.

Complications and costs of patellofemoral arthroplasty versus total knee arthroplasty.

BACKGROUND: Patellofemoral arthroplasty (PFA) is an alternative to total knee arthroplasty (TKA) for the treatment of patellofemoral arthritis. Although PFA may preserve native kinematics and accelerate recovery, it has been associated with higher revision rates. The purpose of this study is to compare complication rates and costs between PFA and TKA. METHODS: Using the PearlDiver database, 6,179 patients with isolated patellofemoral arthritis treated with PFA or TKA from 2010-2015 were retrospectively reviewed with 5-year follow up. PFA and TKA patients were matched by age, sex, and Elixhauser Comorbidity Index via a 1:1 stepwise algorithm. Five-year costs and complications were compared between matched cohorts. The lifetime costs of PFA and TKA were evaluated with Markov decision modeling. RESULTS: Compared to TKA, PFA was associated with fewer Emergency Department (ED) visits (6.1% vs 3.9%, p = 0.004) but a higher 5-year revision rate (9.9% vs 4.2%, p < 0.001). After multivariate regression, PFA was independently more likely to require revision (odds ratio 2.60, 95% confidence interval 1.32-4.71, p = 0.003). PFA was associated with lower total healthcare costs at every time point between 3 months ($18,014 vs $26,473, p < 0.001) and 5 years ($20,837 vs $27,942, p < 0.001). On average, the lifetime cost of PFA per patient was $5,235 less than for TKA ($26,343 vs $31,578). CONCLUSIONS: PFA is a less expensive alternative to TKA with a similar risk of medical complications but is associated with a significantly higher 5-year revision rate. Future studies should examine the reasons for PFA failure and methods to mitigate this risk.

National Trends in Post-Acute Care Costs Following Total Hip Arthroplasty from 2010 through 2018.

BACKGROUND: Post-acute care remains a target for episode-of-care cost reduction following total hip arthroplasty (THA). The introduction of bundled payment models in the United States in 2013 aligned incentives among providers to reduce post-acute care resource utilization. Institution-level studies have shown increased rates of home discharge with substantial cost savings after adoption of bundled payment models; however, national data have yet to be reported. The purpose of this study was to evaluate national trends in post-acute care utilization and costs following primary THA over the last decade. METHODS: We reviewed the cases of 189,847 patients undergoing primary THA during 2010 through 2018 from the PearlDiver database. Annual trends in patient demographics, discharge disposition, and post-acute care resource utilization were evaluated. Post-acute care reimbursements were standardized to 2020 dollars and included outpatient visits, prescriptions, physical therapy, home health, inpatient rehabilitation, skilled nursing facilities, and any rehospitalizations or emergency department (ED) visits within 90 days of surgery. RESULTS: From 2010 to 2018, the mean episode-of-care costs ($31,562 versus $24,188; p < 0.001) and overall post-acute care costs ($5,903 versus $3,485; p < 0.001) both declined. Post-acute care savings were primarily driven by reduced costs of skilled nursing facilities ($1,533 versus $627; p < 0.001), home health ($1,041 versus $763; p = 0.002), inpatient rehabilitation ($949 versus $552; p < 0.001), ED visits ($508 versus $102; p < 0.001), and rehospitalizations ($367 versus $179; p < 0.001). Post-acute care costs declined by $578 (p = 0.025) during 2010 to 2012, $768 (p = 0.038) during 2013 to 2015, and $884 (p = 0.020) during 2016 to 2018. CONCLUSIONS: Over the last decade, the rate of home discharge after THA increased while rehospitalization and ED visit rates declined, resulting in a substantial decrease in total and post-acute care costs. Post-acute care costs declined most rapidly after the introduction of the new Medicare bundled payment programs in 2013 and 2016.