Prior Bariatric Surgery is Associated with Improved Total Hip Arthroplasty Outcomes in Patients Who Have Obesity: A National Cohort Study with 6 Years of Follow-Up.

BACKGROUND: Obesity is a risk factor for end-stage hip osteoarthritis (OA). While total hip arthroplasty (THA) is commonly performed to reduce pain and improve function associated with OA, obesity has been associated with an increased risk of complications after THA. Although bariatric surgery may also be utilized to reduce weight, the impact of bariatric surgery on THA outcomes remains inadequately understood. METHODS: This retrospective cohort analysis utilized multicenter electronic medical record data ranging from 2003 to 2023. Patients who have obesity who underwent THA were stratified based on prior bariatric surgery. The final bariatric cohort comprised 451 patients after propensity score matching. Complication rates and revision risks were compared between cohorts at six, 24, and 72 months. Additional analysis stratified patients by interval between bariatric surgery and THA. RESULTS: At six-month follow-up, the bariatric cohort had significantly lower risks of surgical site infection (SSI), wound dehiscence, and deep vein thrombosis (DVT). At 24 months, the bariatric cohort had a lower risk of DVT. At 72 month follow-up, the bariatric cohort had reduced rates of revision, mortality, cardiac morbidity, and Clavien-Dindo grade IV complications. CONCLUSION: Obese patients who underwent bariatric surgery prior to THA experienced reduced medical complications at all time points and reduced rates of revision at 72 months relative to a matched cohort who did not undergo bariatric surgery.

Identifying Aseptic Revision Total Knee Arthroplasty Diagnoses That Achieve Minimal Clinically Important Difference and Patient Acceptable Symptom State.

BACKGROUND: Minimal clinically important difference (MCID) defines a meaningful clinical change in patient-reported outcome measures. Patient acceptable symptom state (PASS) provides a patient-reported outcome measures threshold value to indicate a satisfactory clinical state. MCID and PASS for revision total knee arthroplasty (rTKA) are ill-defined. Moreover, it is unknown whether diagnosis influences the likelihood of achieving MCID or PASS. The purpose of this study was to calculate MCID for aseptic rTKA and compare the percentage of patients achieving MCID and PASS per diagnosis. METHODS: An institutional registry of rTKA was used. First-time aseptic rTKA were included. Demographics, revision diagnosis, preoperative Knee Injury and Osteoarthritis Outcome Score, Jr (KOOS Jr), and 1-year postoperative KOOS Jr were recorded. The 1-year postoperative KOOS Jr PASS score was available. MCID was calculated using distribution-based methods. Three hundred fifty eight first-time aseptic rTKAs were analyzed. The 3 most common diagnoses were aseptic loosening (n = 156), instability (n = 109), and stiffness (n = 37). RESULTS: The mean KOOS Jr 1-year postoperative MCID for rTKA was 10.3. Overall, 75.4% achieved MCID and 56.9% achieved PASS. The percentage of patients per diagnosis achieving MCID and PASS, respectively, were periprosthetic fracture (100, 44), aseptic loosening (94, 60), implant fracture (88, 63), stiffness (60, 38), instability (59, 61), polyethylene wear/osteolysis (57, 57), and metal allergy (44, 33). CONCLUSION: Aseptic rTKA MCID is 10.3 for KOOS Jr at 1 year postoperatively. rTKA outcomes vary depending on preoperative diagnosis. Even in diagnoses with a high proportion of MCID achieved, less than 2/3 of patients achieved PASS, suggesting rTKA provides noticeable improvement but may not return patients to a satisfactory state.

Fracture of Contemporary Femoral Stems: Common Trends in This Rare Occurrence.

BACKGROUND: Fracture of contemporary femoral stems is a rare occurrence in total hip arthroplasty. A knowledge gap remains regarding manufacturing, patient, and surgeon factors that may contribute to the increased risk of this complication. METHODS: We analyzed 13 contemporary fractured porous-coated femoral stems of various designs to determine cause and contributing factors of mechanical failure. Cases included 12 men and 1 woman who had an average age at index surgery of 53 years (range, 34 to 76 years). There were 10 of 13 patients who had a body mass index more than 30 (obese); 3 of the 10 had a body mass index more than 40. The mean time to fracture was 7.6 years (range, 7 months to 12 years). RESULTS: There were 4 titanium alloy stems that fractured an average of 3.6 years postrevision surgery for head/cup exchange and had associated iatrogenic mechanical and electrocautery damage to the femoral neck at fracture initiation sites. There were 6 modular stems that failed at the stem-sleeve or stem-neck interfaces with evidence of fretting corrosion. For 2 stem-neck fractures, mismatched head/stem combinations from different manufacturers resulted in untested mechanical offsets and loading. There were 2 proximal neck fractures and 1 mid-shaft fracture of coated cobalt-chromium alloy stems that occurred in 3 obese men. The neck fractures (10 to 12 years) were well-fixed stems. Lack of proximal fixation contributed to the mid-shaft fracture (7 months). CONCLUSION: While rare, femoral stem fractures pose catastrophic outcomes in primary and revision total hip arthroplasty. Manufacturing, patient, and surgical factors contributing to stem failures were identified, including patient obesity, heat-treatment reduction of mechanical properties, iatrogenic implant damage, and mixing of different vendor stems and heads.

Mean 16-Year Results of Total Hip Arthroplasty With Alumina Ceramic Femoral Heads on Highly Cross-Linked Polyethylene in Patients 50 Years or Less.

BACKGROUND: Highly cross-linked polyethylene (HXLPE) is a widely used bearing surface in total hip arthroplasty (THA); long-term results in young patients are limited. We previously demonstrated excellent results in HXPLE on cobalt-chrome femoral heads at 15-year mean follow-up. The purpose of the present study was to investigate polyethylene wear rates, implant survivorships, wear-related revisions, and patient-reported outcomes (PROs) in a young patient cohort who had alumina ceramic on HXPLE coupling at an average 16-year follow-up. METHODS: This was a retrospective study of 128 hips that underwent THA with HXLPE on alumina ceramic bearings between March 1, 2004, and April 15, 2007. The patient's mean age was 38 years (range, 13 to 50). All THAs utilized HXPLE liners with alumina ceramic heads. The University of California, Los Angeles activity score and modified Harris hip scores were collected preoperatively and at each follow-up. Martell hip analysis suite was used for wear calculations. RESULTS: At average 16 years (range, 13 to 18), aseptic revision survivorship was 93.3% and osteolysis/wear survivorship was 99.2%. The mean linear wear rate was 0.0191 mm/year and mean volumetric wear rate was 19.43 mm3/y, both of which were clinically undetectable. We observed excellent PROs with a significant increase in mean modified Harris hip scores (43.6 to 87.4, P < .0001) and the University of California, Los Angeles activity scores (4.0 to 6.0, P < .0001). There were no statistically significant differences in PROs or wear rates between ceramic and cobalt-chrome groups. CONCLUSION: At a mean 16-year follow-up, young patients who had HXLPE on ceramic coupling had excellent wear properties, PROs, and acceptable survivorships.

Preoperative ferritin and hemoglobin levels are lower in patients with a history of COVID-19 but blood loss and transfusion requirements are not increased.

INTRODUCTION: A history of COVID-19 (Coronavirus Disease 2019), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may have an impact on hemoglobin and ferritin levels predisposing patients to increased blood transfusion requirements following total joint arthroplasty (TJA). The current study compares ferritin levels, hemoglobin levels, and transfusion rates between SARS-CoV-2 IgG positive and SARS-CoV-2 IgG negative TJA patients. MATERIALS AND METHODS: Preoperative ferritin levels, pre- and postoperative hemoglobin levels, postoperative change in hemoglobin, and transfusion rates of 385 consecutive SARS-CoV-2 IgG positive patients undergoing TJA were compared to those of 5156 consecutive SARS-CoV-2 IgG negative patients undergoing TJA. RESULTS: Preoperative hemoglobin levels were significantly lower in SARS-CoV-2 IgG positive patients [13.3 g/dL (range 8.9-17.7 g/dL)] compared to 13.5 g/dl (7.3-18.3 g/dL; p value 0.03). Ferritin levels were significantly lower in SARS-CoV-2 IgG positive patients (mean of 106.1 ng/ml (2.1-871.3.3 ng/ml) vs. 123.7 ng/ml (1.4-1985 ng/ml) (p value 0.02)). Hemoglobin on postoperative day (POD) one, after four-six weeks, and transfusion rates did not differ between the two groups. CONCLUSION: Although preoperative hemoglobin and ferritin levels are lower in SARS-CoV2 IgG positive patients, there was no difference in hemoglobin on POD one, recovery of hemoglobin levels at four-six weeks postoperatively, and transfusion rates after surgery. Routine ferritin testing prior to TJA is not recommended in SARS-CoV-2 IgG positive patients.

History of COVID-19 infection is not associated with increased D-dimer levels and risk of deep-vein thrombosis in total joint arthroplasty.

INTRODUCTION: In the acute phase of COVID-19, elevated D-dimer levels indicate a hypercoagulable state putting the patients at increased risk for venous thromboembolic disease (VTE). It is unclear, if prior COVID-19 disease increases the risk for VTE after total joint arthroplasty (TJA) and if D-dimer levels can be used to identify patients at risk. MATERIALS AND METHODS: D-Dimer levels of 313 consecutive SARS-CoV-2 IgG-positive and 2,053 -negative patients undergoing TJA between 05/20 and 12/20 were evaluated. D-Dimer levels were divided into three groups: < 200 ng/ml, 200-400 ng/ml, and > 400 ng/ml D-dimer units (DDU). 277 SARS-CoV-2 IgG-positive patients underwent a Doppler ultrasound to rule out deep-vein thrombosis (DVT) 4-6 weeks after TJA. RESULTS: D-Dimer levels did not differ significantly between SARS-CoV-2 IgG-positive and -negative patients (p value 0.53). Among SARS-CoV-2 IgG-negative patients, 1687 (82.17%) had D-dimer levels < 200 ng/ml, 256 (12.47%) between 200 and 400 ng/ml, and 110 (5.36%) > 400 ng/ml. Of the SARS-CoV-2 IgG-positive patients, 257 (83.71%) had D-dimer levels < 200 ng/ml, 34 (11.07%) between 200 and 400 ng/ml, and 16 (5.21%) > 400 ng/ml. A postoperative DVT was detected in nine patients (2.9%) in the SARS-CoV-2 IgG-positive group and a PE in one patient (0.3%). 7/229 patients with < 200 ng/ml (3.1%), 1/28 patients (3.6%) with 200-400 ng/ml and 1/9 patients (11.1%) with D-dimer levels > 400 ng/ml had a DVT or PE (p = 0.43). CONCLUSIONS: The findings of this investigation suggest there is no difference in D-dimer levels between SARS-CoV-2 IgG-positive and -negative patients undergoing TJA. Although there is a trend for increased VTE rates with increased D-dimer levels, routine D-dimer testing is not recommended based on the current data. SARS-CoV-2 IgG-positive patients have a low risk of VTE in the current study.

The Impact of Component Design and Fixation on Stress Shielding After Modern Total Knee Arthroplasty.

BACKGROUND: Total knee arthroplasty (TKA) tibial baseplate thickness, metallurgy, and implant fixation with cement may influence stress shielding. The purpose of the present study is to compare bone mineral density of 2 cemented and press-fit TKA designs with differing tibial baseplate thicknesses and metallurgy over a 2-year period to assess for changes in stress shielding. METHODS: One-hundred one TKAs were performed in this Institutional Review Board-approved, prospective study. There were 4 cohorts: DePuy Attune cemented and press-fit, and Stryker Triathlon cemented and press-fit. The Attune tibial baseplate was thicker; both cemented tibial and femoral components were cobalt-chromium. The DePuy Attune press-fit had a cobalt-chromium sintered bead porous coating while the Stryker Triathlon was 3-dimensional printed highly porous titanium alloy. All patients had quantitative dual-energy X-ray absorptiometry scans performed at baseline (4-6 weeks postoperatively) and at 1 and 2 years postoperatively. Stress shielding was evaluated by comparing percent change in bone mineral density in 11 radiographic zones over 2 years. RESULTS: Over a 2-year period, there were no differences in stress shielding on the tibial side in either cemented or press-fit between Stryker Triathlon and DePuy Attune; however, there were differences on the femoral side. The press-fit tibial components of the Stryker Triathlon and DePuy Attune had either similar or less stress shielding over a 2-year period compared to their cemented counterparts. CONCLUSION: This study comparing 2 TKA implants with differing tibial tray thickness did not find significant differences in tibial stress shielding between designs. There was a difference in stress shielding on the femoral side between designs, suggesting that longer term follow-up is warranted.

Same-Day Discharge Total Hip and Knee Arthroplasty: Trends, Complications, and Readmission Rates.

BACKGROUND: Although total hip arthroplasty (THA) and total knee arthroplasty (TKA) are transitioning to surgery centers, there remain limited data on trends, comorbidities, and complications in patients discharged the same day of surgery. In addition, many studies are limited to the Medicare population, excluding a large proportion of outpatient surgery patients. METHODS: Primary, elective THA/TKA cases between 2010 and 2017 were retrospectively identified using the PearlDiver All-Payer Database and separated based on surgery as well as same-day discharge (SDD) or non-SDD. Data were collected on demographics, rates, comorbidities, and complications. Multivariable logistic regression determined adjusted odds ratios (ORs) for 90-day complications requiring readmission for each group. RESULTS: In total, 1,789,601 (68.8% TKA, 31.2% THA) patients were identified where 2.9% of TKAs and 2.2% of THAs were SDD. Annual SDD rates are increasing, with a 15.8% mean annual change for SDD-THA and 11.1% for SDD-TKA (P < .001). SDD patients were younger with fewer comorbidities (P < .001). Regression analysis showed an overall slightly higher OR of complications requiring readmission for SDD-TKA vs non-SDD-TKA (OR 1.14, 95% confidence interval [CI] 1.07-1.21, P < .001). There was no significant difference for SDD-THA vs non-SDD-THA (OR 1.03, 95% CI 0.94-1.13, P = .49). In univariate analysis, SDD-THA vs SDD-TKA had more mechanical complications (P < .001), but less pulmonary embolisms (P < .001). Regression analysis showed a slightly higher risk of complications for SDD-THA vs SDD-TKA (OR 1.19, 95% CI 0.99-1.44, P = .05). CONCLUSION: The prevalence of SDD is rising. SDD-THA is increasing more rapidly than SDD-TKA. SDD patients are generally younger with fewer comorbidities. SDD-TKA has slightly higher odds of complications requiring readmission than non-SDD-TKA. SDD-THA and SDD-TKA have different complication profiles.

Minimal Clinically Important Difference (MCID) at One Year Postoperatively in Aseptic Revision Total Hip Arthroplasty.

BACKGROUND: Outcomes after aseptic revision total hip arthroplasty (THA) are variable, and it is unknown whether the indication for aseptic revision THA influences postoperative clinical improvement. The minimal clinically important difference (MCID) assesses if changes in patient-reported outcome measure result in meaningful clinical benefit to patients. The purpose of this study was to quantify the 1-year postoperative MCID for aseptic revision THA and to assess the percentage of patients achieving the MCID for each revision diagnosis. METHODS: A prospective, single-institution registry of revision total joint arthroplasties was used. Retrospective review of 413 first-time aseptic revision THAs was performed. Demographics, revision diagnosis, preoperative Hip Disability and Osteoarthritis Outcome Score, Joint Replacement (HOOS Jr.), and 1-year postoperative HOOS Jr. were recorded. The MCID for the HOOS Jr. at one year postoperatively was calculated for each revision diagnosis using a distribution-based method. The percentage of patients exceeding the MCID with each diagnosis was determined. RESULTS: There were 9 aseptic revision diagnoses, all with n ≥ 5. The 3 most common revision diagnosis were aseptic loosening (n = 114), dislocation or instability (n = 103), and polyethylene wear or osteolysis (n = 73). The MCID for all the aseptic revision THAs was 10.9. Seven of the nine revision diagnoses achieved the MCID. The highest percentage of patients achieving the MCID was for aseptic loosening (84.2%) and implant fracture (81.3%), whereas lowest was for adverse local tissue reaction (35.3%) and implant recall (20.0%). CONCLUSION: The one-year revision THA MCID is 10.9 for the HOOS Jr. There is variability in the percentage of patients achieving the MCID based on diagnosis. Our data can be used to counsel patients undergoing revision THA for noninfectious etiologies.

Femoral Component Undersizing and Alignment are Risk Factors for Early Periprosthetic Femur Fracture.

BACKGROUND: Known risk factors for early periprosthetic femur fracture (PFF) following total hip arthroplasty (THA) include poor bone quality and the use of cementless implants. The association between femoral component size and alignment and the risk of early PFF is not well described. We evaluated radiographic parameters of femoral component sizing and alignment as risk factors for early PFF. METHODS: From 16,065 primary cementless THAs, we identified 66 cases (0.41%) of early PFFs (<90 days from index THA) at a single institution between 2016 and 2020. Sixty early PFFs were (1:2) matched to 120 controls based on the femoral component model, offset, surgical approach, age, body mass index (BMI), and gender. Radiographic assessment of preoperative bone morphology and postoperative femoral component orientation included stem alignment, metaphyseal fill, and implant congruence with medial cortical bone. A multivariable logistic regression was built to identify radiographic risk factors associated with early PFF. RESULTS: Markers of preoperative bone quality including canal calcar ratio (P = .003), canal flare index (P < .001), anteroposterior canal bone ratio (CBR) (P < .001), and lateral CBR (P < .001) were statistically associated with PFF. Distance between the medial cortical bone and implant was greater in cases of PFF (2.5 mm vs 1.4 mm) (P < .001). A multivariate analysis demonstrated that a larger lateral metaphyseal CBR (Odds Ratio [OR] 5), valgus implant alignment (OR 5), and medial implant-bone incongruity (OR 2) increased the risk of early PFF. CONCLUSION: A larger lateral metaphyseal CBR, valgus component alignment, and implant incongruity with medial cortical bone posed the greatest radiographic risk for early PFF following cementless THA.

Robotic Assistance for Posterior Approach Total Hip Arthroplasty Is Associated With Lower Risk of Revision for Dislocation When Compared to Manual Techniques.

BACKGROUND: Robotic-assistance total hip arthroplasty (RA-THA) and computer navigation THA (CN-THA) have been shown to improve accuracy of component positioning compared to manual techniques; however, controversy exists regarding clinical benefit. Moreover, these technologies may expose patients to risks. The purpose of this study is to compare rates of intraoperative fracture and complications requiring reoperation within 1 year for posterior approach RA-THA, CN-THA, and THA with no technology (Manual-THA). METHODS: In total, 13,802 primary, unilateral, elective, posterior approach THAs (1770 RA-THAs, 3155 CN-THAs, and 8877 Manual-THAs) were performed at a single institution between 2016 and 2020. Intraoperative fractures and reoperations within 1 year of the index procedure were identified. Cohorts were balanced using inverse probability of treatment weight based on age, gender, body mass index, femoral cementation, history of spine fusion, and Charlson Comorbidity Index. Logistic regression was performed to create odds ratios for complications. Additional regression analysis for dislocation was performed, adjusting for dual mobility and femoral head size. RESULTS: There were no differences in intraoperative fracture and postoperative complication rates between the groups (P = .521). RA-THA had a 0.3 odds ratio (95% confidence interval 0.1-0.9, P = .046) compared to Manual-THA for reoperation due to dislocation. CN-THA had an odds ratio of 3.0 for reoperation due to dislocation (95% confidence interval 0.8-11.3, P = .114) compared to RA-THA. The remaining complication odds ratios, including those for infection, loosening, dehiscence, and "other" were similar between the groups. CONCLUSION: RA-THA is associated with lower risk of revision for dislocation within 1 year of index surgery, when compared to Manual-THA performed through the posterior approach.

Intraoperative Complications and Early Return to the Operating Room in Total Hip Arthroplasty Performed Through the Direct Anterior and Posterior Approaches. An Institutional Experience of Surgeons After Their Learning Curve.

BACKGROUND: Proponents of the direct anterior approach (DAA) for total hip arthroplasty (THA) claim a faster recovery, whereas critics claim an increased risk of early femoral complications. This study analyzed intraoperative and postoperative complications requiring reoperation within one year after THA through the DAA and posterior approach (PA). METHODS: A total of 2348 elective, unilateral DAA THAs in patients with osteoarthritis performed between 2016 and 2019 were matched 1:1 for age (±5 years), gender, body mass index (±5), and femoral fixation with 2348 patients who underwent PA THA during the same period. Mixed-effects logistic regression was used. Odds ratios were reported for the occurrence of intraoperative femoral fracture, postoperative femoral fracture, infection, dislocation, and other etiologies requiring reoperation within one year. RESULTS: Intraoperative femoral fracture occurred in 12 DAA (0.5%) and 14 PA (0.6%) patients. Twenty-five patients (1.06%) in the DAA and 28 (1.19%) in the PA group underwent reoperation within the first year. Reoperations were due to periprosthetic fracture (40%), infection (28%), dislocation (23%), and other (9%). Regression analysis revealed no difference in intraoperative femoral fracture (odds ratio (OR): 0.86, 95% confidence interval (CI): 0.40-1.86, P = .69), postoperative femoral fracture (OR: 1.10, 95% CI: 0.47-2.60, P = .83), infection (OR: 1.50, 95% CI: 0.53-5.23, P = .44), or reoperation within one year for other reasons (OR: 1.50, 95% CI: 0.25-9.00, P = .65). DAA had fewer dislocations requiring reoperation (OR: 0.20, 95% CI: 0.04-0.91, P = .02). CONCLUSION: This comparative study did not find differences in intraoperative or postoperative fracture or infection between DAA and PA. DAA was associated with a lower likelihood of reoperation for dislocation within one year of surgery.

What Is the Appropriate Price for Platelet-Rich Plasma Injections for Knee Osteoarthritis? A Cost-Effectiveness Analysis Based on Evidence From Level I Randomized Controlled Trials.

PURPOSE: To identify the price of treatment at which platelet-rich plasma (PRP) is cost-effective relative to hyaluronic acid (HA) and saline solution intra-articular injections. METHODS: A systemized review process of the PubMed, Embase, and MEDLINE databases was undertaken to identify randomized controlled trials comparing PRP with HA and saline solution with up to 1 year of follow-up. Level I trials that reported Western Ontario and McMaster Universities Arthritis Index Likert scores were included. These scores were converted into utility scores. Cost data were obtained from Centers for Medicare & Medicaid Services fee schedules. Total costs included the costs of the injectable, clinic appointments, and procedures. The change in utility scores from baseline to 6 months and 1 year for the PRP, HA, and saline solution groups was divided by total cost to determine utility gained per dollar and to identify the price needed for PRP to be cost-effective relative to these other injection options. RESULTS: Nine randomized controlled trials met the inclusion criteria. A total of 882 patients were included: 483 in the PRP group, 338 in the HA group, and 61 in the saline solution group. Baseline mean utility scores ranged from 0.55 to 0.57 for the PRP, HA, and saline solution groups. The 6-month gains in utility were 0.12, 0.02, and -0.06, respectively. The 12-month gains in utility from before injection were 0.14, 0.03, and 0.06, respectively. The lowest total costs for HA and saline solution were $681.93 and $516.29, respectively. For PRP to be cost-effective, the total treatment cost would have to be less than $3,703.03 and $1,192.08 for 6- and 12-month outcomes, respectively. CONCLUSIONS: For patients with symptomatic knee osteoarthritis, PRP is cost-effective, from the payer perspective, at a total price (inclusive of clinic visits, the procedure, and the injectable) of less than $1,192.08 over a 12-month period, relative to HA and saline solution. LEVEL OF EVIDENCE: Level I, systematic review.

Preoperative Treatment of Hepatitis C Is Associated With Lower Prosthetic Joint Infection Rates in US Veterans.

BACKGROUND: Hepatitis C virus (HCV) is associated with poorer outcomes in total joint arthroplasty (TJA). Recently, oral direct-acting antivirals (DAAs) have become available for HCV curative treatment. The goal of this study is to determine if HCV may be a modifiable risk factor in TJA by comparing postoperative complications among patients with and without preoperative treatment for HCV. METHODS: US Department of Veterans Affairs dataset of all consecutive primary TJAs performed between 2014 and 2018, when DAAs were available, was retrospectively reviewed. HCV-infected patients were identified using International Classification of Diseases, Ninth and Tenth Revision codes and laboratory values. HCV-infected patients treated prior to TJA with DAA were included in the "treated" group. HCV-infected patients untreated preoperatively were assigned to the "untreated" group. Medical and surgical complications up to 1 year postoperatively were identified using International Classification of Diseases, Ninth and Tenth Revision inpatient and outpatient codes. RESULTS: In total, 42,268 patients underwent TJA at Veterans Affairs Hospitals between 2014 and 2018. About 6.0% (n = 2557) of TJA patients had HCV, 17.3% of whom received HCV treatment preoperatively. When evaluating inpatient and outpatient codes, implant infection rates were statistically lower at 90 days and 1 year postoperatively among HCV-treated patients than among those untreated. Odds ratios (ORs) favor lower infection rates in HCV-treated patients (90-day OR: 3.30, P = .045; 1-year OR: 2.16, P = .07). CONCLUSION: Preoperative HCV treatment was associated with lower periprosthetic infection rates among US veterans undergoing TJA. Further investigation is necessary for definitive conclusions.

Machine Learning Algorithms Can Use Wearable Sensor Data to Accurately Predict Six-Week Patient-Reported Outcome Scores Following Joint Replacement in a Prospective Trial.

BACKGROUND: Tracking patient-generated health data (PGHD) following total joint arthroplasty (TJA) may enable data-driven early intervention to improve clinical results. We aim to demonstrate the feasibility of combining machine learning (ML) with PGHD in TJA to predict patient-reported outcome measures (PROMs). METHODS: Twenty-two TJA patients were recruited for this pilot study. Three activity trackers collected 35 features from 4 weeks before to 6 weeks following surgery. PROMs were collected at both endpoints (Hip and Knee Disability and Osteoarthritis Outcome Score, Knee Osteoarthritis Outcome Score, and Veterans RAND 12-Item Health Survey Physical Component Score). We used ML to identify features with the highest correlation with PROMs. The algorithm trained on a subset of patients and used 3 feature sets (A, B, and C) to group the rest into one of the 3 PROM clusters. RESULTS: Fifteen patients completed the study and collected 3 million data points. Three sets of features with the highest R2 values relative to PROMs were selected (A, B and C). Data collected through the 11th day had the highest predictive value. The ML algorithm grouped patients into 3 clusters predictive of 6-week PROM results, yielding total sum of squares values ranging from 3.86 (A) to 1.86 (C). CONCLUSION: This small but critical proof-of-concept study demonstrates that ML can be used in combination with PGHD to predict 6-week PROM data as early as 11 days following TJA surgery. Further study is needed to confirm these findings and their clinical value.

Optimal Sampling Frequency for Wearable Sensor Data in Arthroplasty Outcomes Research. A Prospective Observational Cohort Trial.

BACKGROUND: Wearable sensors can track patient activity after surgery. The optimal data sampling frequency to identify an association between patient-reported outcome measures (PROMs) and sensor data is unknown. Most commercial grade sensors report 24-hour average data. We hypothesize that increasing the frequency of data collection may improve the correlation with PROM data. METHODS: Twenty-two total joint arthroplasty (TJA) patients were prospectively recruited and provided wearable sensors. Second-by-second (Raw) and 24-hour average data (24Hr) were collected on 7 gait metrics on the 1st, 7th, 14th, 21st, and 42nd days postoperatively. The average for each metric as well as the slope of a linear regression for 24Hr data (24HrLR) was calculated. The R2 associations were calculated using machine learning algorithms against individual PROM results at 6 weeks. The resulting R2 values were defined having a mild, moderate, or strong fit (R2 ≥ 0.2, ≥0.3, and ≥0.6, respectively) with PROM results. The difference in frequency of fit was analyzed with the McNemar's test. RESULTS: The frequency of at least a mild fit (R2 ≥ 0.2) for any data point at any time frame relative to either of the PROMs measured was higher for Raw data (42%) than 24Hr data (32%; P = .041). There was no difference in frequency of fit for 24hrLR data (32%) and 24Hr data values (32%; P > .05). Longer data collection improved frequency of fit. CONCLUSION: In this prospective trial, increasing sampling frequency above the standard 24Hr average provided by consumer grade activity sensors improves the ability of machine learning algorithms to predict 6-week PROMs in our total joint arthroplasty cohort.

A Comparison of Radiographic Outcomes After Total Hip Arthroplasty Between the Posterior Approach and Direct Anterior Approach With Intraoperative Fluoroscopy.

BACKGROUND: Radiographic outcomes after total hip arthroplasty (THA) have been linked to clinical outcomes. The direct anterior approach (DAA) for THA has been criticized by some for providing limited exposure and compromised implant position but allows for routine use of intraoperative fluoroscopy. We sought to determine whether radiographic measurements differed by THA approach using prospective cohorts. METHODS: Two reviewers blinded to surgical approach examined 194 radiographs, obtained 4-6 weeks after primary THA, and obtained measurements for acetabular inclination angle, acetabular anteversion, radiographic limb length discrepancy (LLD), and femoral offset. All surgeries were performed at a tertiary academic medical center in rural New England by an experienced fellowship-trained arthroplasty surgeon. Measurements for inclination angle, anteversion, LLD, and offset were made into binary yes/no responses based on whether the mean measurement (between the 2 reviewers) was acceptable or not based on established criteria. Multivariate logistic regression analyses were performed using preoperative and intraoperative characteristics to identify predictors of acceptability for each measurement. RESULTS: The DAA group had higher rates of acceptable acetabular angle (96 vs 85%, P = .005) and was protective against an unacceptable angle in an adjusted predictive model (odds ratios 0.16, P = .005). There were no significant differences between approaches for acceptable anteversion, LLD, or offset. Body mass index of 30-34 was associated with higher odds of unacceptable inclination angle compared to the nonobese group (adjusted odds ratio, 6.82, P = .013). CONCLUSION: DAA for THA was associated with lower odds of unacceptable inclination angle compared to the posterior approach, with no differences in anteversion, LLD, or offset.

Higher Patient Expectations Predict Higher Patient-Reported Outcomes, But Not Satisfaction, in Total Knee Arthroplasty Patients: A Prospective Multicenter Study.

BACKGROUND: The relationship between patient expectations, patient-reported outcomes (PROs), and satisfaction in total knee arthroplasty (TKA) patients is not well understood. METHODS: We prospectively evaluated patients who underwent primary TKA at 4 institutions. Demographics were collected. Preoperatively, patients completed the Hospital for Special Surgery Knee Replacement Expectations Survey (HSS-KRES), SF-12, UCLA activity, and Knee Disability and Osteoarthritis Score. At 6 months and 1 year postoperatively, patients completed the Hospital for Special Surgery Knee Replacement Fulfillment of Expectations Survey (HSS-KRFES), a satisfaction survey, and PROs. Step-wise multivariate regression models were created. RESULTS: Eighty-three patients were enrolled. At 6 months and 1 year postoperatively, the follow-up rate was 84.3% and 92.7%, respectively. No demographics or preoperative PROs were predictive of HSS-KRES. Preoperative HSS-KRES did not predict postoperative satisfaction, but higher HSS-KRES predicted higher HSS-KRFES at 1 year, greater improvement in UCLA activity at 6 months and 1 year, and SF-12 Physical Composite Scale and Knee Disability and Osteoarthritis Score at 6 months. Higher HSS-KRFES predicted higher satisfaction at 6 months and 1 year. CONCLUSION: In TKA patients, preoperative expectations are not influenced by patient demographics or preoperative function. Higher preoperative expectations predict greater postoperative improvement in PROs and fulfillment of expectations. These findings highlight the importance of preoperative patient expectations on postoperative outcome.

Do Patient Expectations Influence Patient-Reported Outcomes and Satisfaction in Total Hip Arthroplasty? A Prospective, Multicenter Study.

BACKGROUND: The relationship between patient expectations and patient-reported outcomes (PROs) in total hip arthroplasty (THA) patients is controversial. The purpose of this study was to examine the impact of preoperative patient expectations on postoperative PROs and patient satisfaction. METHODS: This was a prospective multicenter observational cohort study of primary THA patients. Preoperatively, patients completed Hospital for Special Surgery (HSS) Hip Replacement Expectations Survey (expectations), 12 item Short Form Survey (SF-12), University of California, Los Angeles (UCLA) activity score, and Hip Disability and Osteoarthritis Score (HOOS). Postoperatively at 6 months and 1 year, patients completed the Hospital for Special Surgery Hip Replacement Fulfillment of Expectations Survey (fulfillment of expectations), a satisfaction survey, and the same PROs as preoperatively. Stepwise multivariate regression models were created. RESULTS: A total of 207 patients were enrolled. Follow-up rate was 91% at 6 months and 92% at 1 year. Being employed and lower baseline HOOS predicted higher expectations (employment status: B = -7.5, P = .002; HOOS: B = -0.27, P = .002). Higher preoperative expectations predicted greater improvements in UCLA activity, SF-12 physical component score, and HOOS at 6 months (UCLA activity: B = 0.03, P = .001; SF-12 physical component score: B = 0.15, P = .001; HOOS: B = 0.20; P = .008) and UCLA activity at 1 year (B = 0.02, P = .004). Furthermore, higher expectations predicted higher postoperative satisfaction and fulfillment of expectations at 6 months (satisfaction: B = 0.21, P < .001; fulfillment of expectations: B = 0.30, P < .001) and higher fulfillment of expectations at 1 year (B = 0.17, P = .006). CONCLUSION: In patients undergoing THA, being employed and worse preoperative hip function predict of higher preoperative expectations of surgery. Higher expectations predict greater improvement in PROs, greater patient satisfaction, and the fulfillment of expectations. These findings can be used to guide patient counseling and shared decision making preoperatively.

Hepatitis C infection and complication rates after total shoulder arthroplasty in United States veterans.

BACKGROUND: Few studies have evaluated the effect of hepatitis C (HCV) on primary total shoulder arthroplasty (TSA). Our purpose was to determine if HCV infection is associated with increased complication rates after TSA in United States (US) veterans and, secondarily, to determine if preoperative HCV treatment with direct-acting antivirals (DAAs) affects postoperative complication rates. METHODS: US Department of Veterans Affairs (VA) data sets were used to retrospectively identify patients without HCV, patients with untreated HCV, and patients with HCV treated with DAAs who underwent TSA from 2014 to 2019. Medical and surgical complications were assessed using International Classification of Diseases codes. Complication rates between patients with HCV (treated and untreated) and patients without HCV and between HCV-treated patients and HCV-untreated patients were compared at 90 days and 1 year after surgery. RESULTS: We identified 5774 primary TSAs that were performed at VA hospitals between 2014 and 2019. A minority (9.5%) of TSA patients had HCV, 23.4% of whom were treated preoperatively with DAAs. On multivariate analysis, HCV patients had increased odds of 1-year medical complications (odds ratio, 1.39; 95% confidence interval, 1.06-1.81, P = .016), when compared with patients without HCV. No statistically significant difference in complication rates was observed between HCV-treated and HCV-untreated patients. DISCUSSION: US veterans with a history of HCV are at an increased risk of developing medical but not surgical complications within the first year after TSA. Larger studies are necessary to evaluate the effects of DAA treatment on complication rates.