Mental Robustness May Be Associated With Improved Physical Function in Bilateral Total Knee Arthroplasty Patients.

BACKGROUND: In accordance with the high incidence of bilateral knee osteoarthritis, many patients have undergone bilateral total knee arthroplasty (BTKA). Whether patients undergo bilateral procedures in a staged or simultaneous fashion, the physical and mental burden of undergoing 2 major orthopedic procedures is considerable. The aims of this study were to (1) investigate differences between minimal clinically important difference (MCID) achievement between staged versus simultaneous BTKA, and (2) identify the patient variables, specifically mental scores, that were associated with MCID achievement in patients undergoing BTKA. METHODS: Simultaneous and staged BTKA patients within a single health care network from 2016 to 2021 were retrospectively reviewed. Patient demographics, surgery details, and Patient-Reported Outcome Measurement Information System Physical Function Short Forms 10a (PROMIS PF10a), PROMIS Mental scores, and Knee Disability Osteoarthritis Outcome Scores (KOOS) were reviewed. Preoperative and postoperative patient-reported outcome measures were collected before the first total knee arthroplasty (TKA) and after the second TKA, respectively, in staged BTKA patients. The final cohort consisted of 249 patients, with an average age of 66 years (range, 21 to 87), 63% women, and an average body mass index of 32 (range, 20 to 52), at a mean follow-up of 1.1 years (range, 0.5 to 2.4). Multivariate regressions were performed on MCID PF10a and KOOS achievement, as well as whether the BTKA was performed simultaneously versus staged. RESULTS: A preoperative PROMIS Mental score in the upper 2 quartiles was associated with MCID PF10a achievement in BTKA. Men and surgeries performed at an Academic Medical Center were negatively associated with the achievement of MCID KOOS. Interestingly, those who underwent simultaneous BTKA were less likely to achieve MCID KOOS than those who underwent a staged BTKA. CONCLUSIONS: Preoperative mental robustness may be positively associated with improved physical function outcome in BTKA patients.

Which Factors Are Considered by Patients When Considering Total Joint Arthroplasty? A Discrete-choice Experiment.

BACKGROUND: TKA and THA are major surgical procedures, and they are associated with the potential for serious, even life-threatening complications. Patients must weigh the risks of these complications against the benefits of surgery. However, little is known about the relative importance patients place on the potential complications of surgery compared with any potential benefit the procedures may achieve. Furthermore, patient preferences may often be discordant with surgeon preferences regarding the treatment decision-making process. A discrete-choice experiment (DCE) is a quantitative survey technique designed to elicit patient preferences by presenting patients with two or more hypothetical scenarios. Each scenario is composed of several attributes or factors, and the relative extent to which respondents prioritize these attributes can be quantified to assess preferences when making a decision, such as whether to pursue lower extremity arthroplasty. QUESTIONS/PURPOSES: In this DCE, we asked: (1) Which patient-related factors (such as pain and functional level) and surgery-related factors (such as the risk of infection, revision, or death) are influential in patients' decisions about whether to undergo lower extremity arthroplasty? (2) Which of these factors do patients emphasize the most when making this decision? METHODS: A DCE was designed with the following attributes: pain; physical function; return to work; and infection risks, reoperation, implant failure leading to premature revision, deep vein thrombosis, and mortality. From October 2021 to March 2022, we recruited all new patients to two arthroplasty surgeons' clinics who were older than 18 years and scheduled for a consultation for knee- or hip-related complaints who had no previous history of a primary TKA or THA. A total of 56% (292 of 517) of new patients met the inclusion criteria and were approached with the opportunity to complete the DCE. Among the cohort, 51% (150 of 292) of patients completed the DCE. Patients were administered the DCE, which consisted of 10 hypothetical scenarios that had the patient decide between a surgical and nonsurgical outcome, each consisting of varying levels of eight attributes (such as infection, reoperation, and ability to return to work). A subsequent demographic questionnaire followed this assessment. To answer our first research question about the patient-related and surgery-related factors that most influence patients' decisions to undergo lower extremity arthroplasty, we used a conditional logit regression to control for potentially confounding attributes from within the DCE and determine which variables shifted a patient's determination to pursue surgery. To answer our second question, about which of these factors received the greatest priority by patients, we compared the relevant importance of each factor, as determined by each factor's beta coefficient, against each other influential factor. A larger absolute value of beta coefficient reflects a relatively higher degree of importance placed on a variable compared with other variables within our study. Of the respondents, 57% (85 of 150) were women, and the mean age at the time of participation was 64 ± 10 years. Most respondents (95% [143 of 150]) were White. Regarding surgery, 38% (57 of 150) were considering THA, 59% (88 of 150) were considering TKA, and 3% (5 of 150) were considering both. Among the cohort, 49% (74 of 150) of patients reported their average pain level as severe, or 7 to 10 on a scale from 0 to 10, and 47% (71 of 150) reported having 50% of full physical function. RESULTS: Variables that were influential to respondents when deciding on lower extremity total joint arthroplasty were improvement from severe pain to minimal pain (ß coefficient: -0.59 [95% CI -0.72 to -0.46]; p < 0.01), improvement in physical function level from 50% to 100% (ß: -0.80 [95% CI -0.9 to -0.7]; p < 0.01), ability to return to work versus inability to return (ß: -0.38 [95% CI -0.48 to -0.28]; p < 0.01), and the surgery-related factor of risk of infection (ß: -0.22 [95% CI -0.30 to -0.14]; p < 0.01). Improvement in physical function from 50% to 100% was the most important for patients making this decision because it had the largest absolute coefficient value of -0.80. To improve physical function from 50% to 100% and reduce pain from severe to minimal because of total joint arthroplasty, patients were willing to accept a hypothetical absolute (and not merely an incrementally increased) 37% and 27% risk of infection, respectively. When we stratified our analysis by respondents' preoperative pain levels, we identified that only patients with severe pain at the time of their appointment found the risk of infection influential in their decision-making process (ß: -0.27 [95% CI -0.37 to -0.17]; p = 0.01) and were willing to accept a 24% risk of infection to improve their physical functioning from 50% to 100%. CONCLUSION: Our study revealed that patients consider pain alleviation, physical function improvement, and infection risk to be the most important attributes when considering total joint arthroplasty. Patients with severe baseline pain demonstrated a willingness to take on a hypothetically high infection risk as a tradeoff for improved physical function or pain relief. Because patients seemed to prioritize postoperative physical function so highly in our study, it is especially important that surgeons customize their presentations about the likelihood an individual patient will achieve a substantial functional improvement as part of any office visit where arthroplasty is discussed. Future studies should focus on quantitatively assessing patients' understanding of surgical risks after a surgical consultation, especially in patients who may be the most risk tolerant. CLINICAL RELEVANCE: Surgeons should be aware that patients with the most limited physical function and the highest baseline pain levels are more willing to accept the more potentially life-threatening and devastating risks that accompany total joint arthroplasty, specifically infection. The degree to which patients seemed to undervalue the harms of infection (based on our knowledge and perception of those harms) suggests that surgeons need to take particular care in explaining the degree to which a prosthetic joint infection can harm or kill patients who develop one.

Utility of Diagnostic Markers in Late Periprosthetic Joint Infection Workup for Total Knee Arthroplasty Patients Who Received Antibiotics 48 Hours Before Aspiration.

BACKGROUND: Diagnosing periprosthetic joint infection (PJI) following total knee arthroplasty (TKA) remains challenging despite recent advancements in testing and evolving criteria over the last decade. Moreover, the effects of antibiotic use on diagnostic markers are not fully understood. Thus, this study sought to determine the influence of antibiotic use within 48 hours before knee aspiration on synovial and serum laboratory values for suspected late PJI. METHODS: Patients who underwent a TKA and subsequent knee arthrocentesis for PJI workup at least 6 weeks after their index arthroplasty were reviewed across a single healthcare system from 2013 to 2020. Median synovial white blood cell (WBC) count, synovial polymorphonuclear (PMN) percentage, serum erythrocyte sedimentation rate (ESR), serum C-reactive protein (CRP), and serum WBC count were compared between immediate antibiotic and nonantibiotic PJI groups. Receiver operating characteristic (ROC) curves and Youden's index were used to determine test performance and diagnostic cutoffs for the immediate antibiotics group. RESULTS: The immediate antibiotics group had significantly more culture-negative PJIs than the no antibiotics group (38.1 versus 16.2%, P = .0124). Synovial WBC count demonstrated excellent discriminatory ability for late PJI in the immediate antibiotics group (area under curve, AUC = 0.97), followed by synovial PMN percentage (AUC = 0.88), serum CRP (AUC = 0.86), and serum ESR (AUC = 0.82). CONCLUSION: Antibiotic use immediately preceding knee aspiration should not preclude the utility of synovial and serum lab values for the diagnosis of late PJI. Instead, these markers should be considered thoroughly during infection workup considering the high rate of culture-negative PJI in these patients. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Visceral Fat as a Risk Factor for Periprosthetic Joint Infection After Total Hip and Knee Arthroplasty.

BACKGROUND: Visceral obesity, a strong indicator of chronic inflammation and impaired metabolic health, has been shown to be associated with poor postoperative outcomes and complications. This study aimed to evaluate the relationship between visceral fat area (VFA) and periprosthetic joint infection (PJI) in total joint arthroplasty (TJA) patients. METHODS: A retrospective study of 484 patients who had undergone a total hip or knee arthroplasty was performed. All patients had a computed tomography scan of the abdomen/pelvis within two years of their TJA. Body composition data (ie, VFA, subcutaneous fat area, and skeletal muscle area) were calculated at the Lumbar-3 vertebral level via two fully automated and externally validated machine learning algorithms. A multivariable logistic model was created to determine the relationship between VFA and PJI, while accounting for other PJI risk factors. Of the 484 patients, 31 (6.4%) had a PJI complication. RESULTS: The rate of PJI among patients with VFA in the top quartile (> 264.1 cm2) versus bottom quartile (< 82.6 cm2) was 5.6% versus 10.6% and 18.8% versus 2.7% in the total hip arthroplasty and total knee arthroplasty cohorts, respectively. In the multivariate model, total knee arthroplasty patients with a VFA in the top quartile had a 30.5 times greater risk of PJI than those in the bottom quartile of VFA (P = .0154). CONCLUSION: VFA may have a strong association with PJI in TJA patients. Using a standardized imaging modality like computed tomography scans to calculate VFA can be a valuable tool for surgeons when assessing risk of PJI.

Defining Failure in Primary Total Joint Arthroplasty: The Minimal Clinically Important Difference for Worsening Score.

BACKGROUND: We define the value of the Minimal Clinically Important Difference for Worsening (MCID-W) for Patient-Reported Outcomes Measurement Information System Physical Function short form 10-a (PROMIS-PF-10a) score for primary total joint arthroplasty (TJA) of the hip and knee and describe the risk factors for patients scoring worse than the MCID-W. METHODS: This retrospective study was performed using 3414 primary TJA patients. PROMIS-PF-10a scores were collected at the preoperatively and postoperatively, and patients were classified based on reaching Minimal Clinically Importance Difference for Improvement (MCID-I), MCID-W, or "no significant change" after TJA (scores betweex`n MCID-W and MCID-I). MCID-W and MCID-I values were determined by a distribution method. The association between numerous variables and scoring worse than the MCID-W of PROMIS-PF-10a was then evaluated through multiple logistic regression. A threshold for preoperative PROMIS-PF-10a score predicting decline past MCID-W was determined using the Youden index and receiver operating characteristic curve. RESULTS: The MCID-W for TJA was -1.89. Notably, increasing length of stay (odds ratio [OR] 1.073, 95% confidence interval [CI] 1.029-1.119, P < .001) and increasing preoperative PROMIS-PF-10a scores (OR 1.117, 95% CI 1.091-1.144, P < .001) were associated with increased likelihood of decline past the MCID-W of the PROMIS-PF-10a for TJA compared with patients who achieved the MCID-I. A community hospital with a dedicated joint replacement center was associated with a decreased risk for decline past the MCID-W (OR 0.601, 95% CI 0.402-0.899; P = .013). CONCLUSION: We described the MCID-W value (-1.89) for the PROMIS-PF-10a questionnaire for knee and hip TJA and associated patient- and hospital-level risk factors for failure after TJA. Healthcare funding initiatives should be directed toward modifiable factors associated with clinically significant worse outcomes after TJA.

Patient-Reported Mental Health Score Influences Physical Function After Primary Total Knee Arthroplasty.

BACKGROUND: Despite the effectiveness of total knee arthroplasty (TKA), patients often have lingering pain and dysfunction. Recent studies have raised concerns that preoperative mental health may negatively affect outcomes after TKA. The primary aim of this study investigates the relationship between patient-reported mental health and postoperative physical function following TKA. METHODS: A retrospective study of 1392 primary TKA patients was performed. Mental health and physical function scores were measured using the Patient-Reported Outcomes Measurement Information System (PROMIS) Global Health, and PROMIS Physical Function 10a and Knee injury and Osteoarthritis Outcome Score Physical Function (KOOS-PS) short forms. These assessments were completed preoperatively and up to 1-year postoperatively. Patients were stratified based on preoperative mental health scores into five distinct categories ranging from "Poor" to "Excellent." Locally estimated scatter plot smoothing curves (LOESS) were fit to the data examining physical function score trends over time. RESULTS: Patients with higher mental health scores before surgery demonstrated better preoperative and postoperative physical function scores. However, all patients experienced similar gains in physical function following surgery. Despite this early improvement, patients with the worst mental health scores experienced a sharp decline in physical function approximately a year after surgery and did not appear to recover. CONCLUSIONS: Poor mental health should not be a contraindication for performing TKA. For patients with the lowest mental health scores, physicians should account for the possibility that physical function scores may deteriorate a year after surgery. Tighter follow-up guidelines, more frequent physical therapy visits, or treatment for mental health issues may be considered to counter such deterioration.

Elevated Body Mass Index Is a Risk Factor for Failure to Achieve the Knee Disability and Osteoarthritis Outcome Score-Physical Function Short Form Minimal Clinically Important Difference Following Total Knee Arthroplasty.

BACKGROUND: The aims of this study are (1) to assess the association between body mass index (BMI) and failure to achieve the 1-year Knee Disability and Osteoarthritis Outcome Score-Physical Function Short Form (KOOS-PS) minimal clinically important difference (MCID) for total knee arthroplasty (TKA) patients and (2) to determine if there is a BMI threshold beyond which the risk of failing to achieve the MCID is significantly increased. METHODS: A regional arthroplasty registry was queried for TKA patients from 2016 to 2019 with completion of preoperative and 1-year postoperative KOOS-PS. The MCID threshold was derived using a distribution-based approach. Demographic and patient-reported outcome measure variables were collected. BMI was analyzed continuously and categorically using cutoffs defined by the Centers for Disease Control and Prevention. The association between failure to achieve 1-year MCID and BMI was analyzed using multiple logistic regression. A BMI threshold was determined using the Youden index and receiver operating characteristic curve. RESULTS: In total, 1059 TKAs were analyzed. BMI assessed continuously was significantly associated with failure to achieve the KOOS-PS MCID (odds ratio 1.03, 95% confidence interval 1.00-1.05, P = .025). Analysis of BMI categorically revealed that "overweight" (25-30 kg/m2), "obese class I" (30-35 kg/m2), "obese class II" (35-40 kg/m2), and "obese class III" (>40 kg/m2) patients faced 77%, 76%, 83%, and 106% greater risk, respectively, of failing to achieve the KOOS-PS MCID compared to "normal BMI" (<25 kg/m2) patients. CONCLUSION: Elevated BMI was associated with an increased risk of failure to achieve the 1-year KOOS-PS MCID following TKA.

Low Body Mass Index Is a Predictor for Mortality and Increased Length of Stay Following Total Joint Arthroplasty.

BACKGROUND: Malnutrition is a devastating condition which disproportionally affects the elderly population. Malnutrition furthers the pre-existing elevated risk for osteoarthritis in this population, thus exacerbating joint damage in patients and furthering the need for total joint arthroplasty (TJA). A marker for malnutrition is a low body mass index (BMI). The purpose of this study is to investigate whether low BMI status increased the risk for 2-year mortality or reoperation, 90-day readmission, or extended length of stay (LOS) following TJA. METHODS: A retrospective study was performed using the Partners Arthroplasty Registry which contains data from 2016 to 2019. The registry was queried for primary total hip and primary total knee arthroplasty (TKA) patients that had a minimum of 2-years follow-up data. Demographic, surgical, and clinical outcome variables were obtained from these patients. The association between underweight BMI and objective outcomes of reoperation, 90-day readmission, mortality, and LOS was evaluated by univariate analysis followed by multiple logistic and linear regression analyses. RESULTS: The final cohort used for analysis consisted of 4802 TJA cases. After accounting for potential confounders, underweight BMI was found to be independently associated with increased risk of mortality within 2 years following TJA (odds ratio 8.77) (95% confidence interval 2.14-32.0) and increased LOS of 0.44 days (95% confidence interval 0.02-0.86). CONCLUSION: Our findings demonstrate that TJA patients with an underweight BMI experience an 8 times increased risk of 2-year mortality and an increased LOS of 0.44 days. Orthopedic surgeons should consider nutritional consultation and medical optimization in these high-risk patients prior to surgery.

Obesity Increases Risk of Failure to Achieve the 1-Year PROMIS PF-10a Minimal Clinically Important Difference Following Total Joint Arthroplasty.

INTRODUCTION: The aims of this study were to determine if increasing body mass index (BMI) is a risk factor for failure to attain the 1-year Patient Reported Outcomes Measurement Information System Physical Function (PROMIS PF-10a) minimal clinically important difference (MCID) following total joint arthroplasty (TJA) and to determine a possible BMI threshold beyond which this risk increases significantly. METHODS: This retrospective study was performed using 3506 TJAs sourced from a regional-based registry. An anchor-based MCID threshold of 7.9 was chosen. PROMIS PF-10a scores were collected at the preoperative and 1-year postoperative timepoints, and the change was used to determine failure to achieve the 1-year MCID. Demographic and surgical variables were also collected. The association between BMI and failure to achieve 1-year PROMIS PF-10 MCID was then evaluated using logistic regression. A BMI threshold was determined using receiver operating characteristic (ROC) curve analysis. RESULTS: Increasing BMI assessed continuously was a significant risk factor for failure to achieve the MCID (P < .001). "Obese Class I" (30-35 kg/m2), "Obese Class II" (35-40 kg/m2), and "Obese Class III" (>40 kg/m2) subgroups compared to "Normal BMI" (<25 kg/m2) were significantly associated (P < .05) with this adverse outcome as well. CONCLUSION: Our study showed that increasing BMI is a risk factor for failure to achieve the 1-year PROMIS PF-10a MCID following TJA. Among our patients, an increase in 1 kg/m2 increased the risk of failure to achieve the MCID by 2%. With these findings, surgeons will be better equipped to preoperatively advise patients with elevated BMIs considering TJA.

Class III Obesity Increases Risk of Failure to Achieve the 1-Year Hip Disability and Osteoarthritis Outcome Score-Physical Function Short Form Minimal Clinically Important Difference Following Total Hip Arthroplasty.

BACKGROUND: The relationship between obesity and failure to achieve a minimal clinically important difference (MCID) following total hip arthroplasty (THA) has not been well defined. The aims of this study are to determine whether increasing body mass index (BMI) is associated with failure to achieve the 1-year Hip Disability and Osteoarthritis Outcome Score-Physical Function Short Form (HOOS-PS) MCID and to determine a threshold BMI beyond which this risk is significantly increased. METHODS: A multi-institutional arthroplasty registry was queried for THA patients from 2016 to 2018 with completion of preoperative and 1-year postoperative HOOS-PS. A previously defined anchor-based MCID threshold of 23 was used. Variables collected included demographics and patient-reported outcome measures. BMI was analyzed continuously and categorically. The association was analyzed via logistic regression. A BMI threshold was determined using the Youden index and receiver operating characteristic curve. RESULTS: A total of 1256 THAs were included. The average HOOS-PS improvement was 27.6 ± 18 points. The area under the receiver operating characteristic curve for BMI and risk of failure to achieve HOOS-PS MCID was 0.54 (95% confidence interval [CI], 0.50-0.57). Increasing BMI assessed continuously was a significant risk factor (odds ratio [OR], 1.03; 95% CI, 1.01-1.05; P value = .010). When BMI was analyzed categorically, this association was only observed for obese class III patients (>40 kg/m2) (OR, 2.5; 95% CI, 1.21-5.3; P value = .010). CONCLUSION: This study found an association between increasing BMI and failure to achieve the 1-year HOOS-PS MCID. Obese class III patients (>40 kg/m2) face a near 3-fold increased risk of suffering this adverse outcome.

Morbid Obesity Is a Risk Factor for Infection Recurrence Following Debridement, Antibiotics, and Implant Retention for Periprosthetic Joint Infection.

BACKGROUND: Although morbid obesity is an established risk factor for periprosthetic joint infection following total hip arthroplasty and total knee arthroplasty, little is known regarding the infection control rate of this cohort following debridement, antibiotics, and implant retention (DAIR). The purpose of this study is to investigate the infection control rate following DAIR in a morbidly obese patient cohort compared to a nonobese patient cohort and discern the relationship between time from diagnosis to treatment and risk of DAIR failure. METHODS: Results of all DAIR procedures were retrospectively reviewed across 4 institutions. Those with a body mass index of at least 40 kg/m2 were matched 2:1 on the basis of patient age, sex, date of surgery, and presence of staphylococcal species in culture to a cohort of patients with body mass index of <30 kg/m2. Demographic variables were collected for each patient. Kaplan-Meier survivorship curves were constructed and multivariable Cox regression was performed for analysis. RESULTS: The morbidly obese group experienced a higher treatment failure rate (57.9%) compared to the nonobese group (36.8%; P = .035). Morbid obesity and major depressive disorder/generalized anxiety disorder diagnosis significantly increased the risk of failure, with hazard ratios of 1.82 and 2.09, respectively. Morbidly obese patients who received DAIR within 48 hours of symptom presentation did not face an increased risk of reinfection compared to nonobese patients. CONCLUSION: Our findings suggest morbidly obese patients face an increased risk of DAIR failure; however, this risk can be mitigated if DAIR is received within 48 hours of symptom onset.

Do All Rigid and Unbalanced Spines Present the Same Risk of Dislocation After Total Hip Arthroplasty? A Comparison Study Between Patients With Ankylosing Spondylitis and History of Spinal Fusion.

BACKGROUND: Spines with ankylosis or with a history of lumbosacral fusions have been collectively classified as rigid and unbalanced, and associated with an increased rate of dislocation after total hip arthroplasty (THA). It remains unknown whether the cause of spinal arthrodesis influences the dislocation rate. METHODS: A retrospective study was conducted from January 2000 to December 2017, with an institutional review board's approval to identify 2 cohorts with a history of THA: one with ankylosing spondylitis (AS) involving the lumbosacral spine and another cohort with a history of lumbosacral spinal fusion (SF). A chart review was performed to collect demographic and surgical variables. Lumbar lordosis angle (LLA), acetabular anteversion, and inclination angle measurements were taken for each patient. Kaplan-Meier survivorship curves were constructed and multivariable Cox regression was performed for analysis. RESULTS: The AS and SF cohorts consisted of 142 and 135 patients, respectively. The SF group had a greater mean LLA (34.18°) than the AS group (21°). A total of 16 patients (11.85%) suffered from dislocation after primary elective THA in the SF group, whereas 4 patients (2.82%) in the AS group. After multivariable Cox regression analysis, increasing LLA and hips outside of the Lewinnek safe zone were found to be associated with a higher hazard of dislocation after THA. CONCLUSION: We found that the degree of lumbar spine curvature is more associated with dislocation after THA than the history of SF itself; specifically, an increase in lumbar lordosis angle of 1º increases the probability of dislocation by 13% among AS and SF patients.

Dual Surgical Setup May Improve Infection Control Rate of Debridement and Implant Retention Procedures for Periprosthetic Infections of the Hip and Knee.

BACKGROUND: Debridement, antibiotics, and implant retention (DAIR) is an appealing treatment option for periprosthetic joint infection (PJI) due to its low cost and low morbidity. There are many nonmodifiable risk factors for DAIR failure that have previously been established. A dual DAIR setup constitutes establishing a new, sterile field after the initial debridement. The purpose of this study is to determine whether the modifiable surgical technique of a dual setup improves the infection control rate following PJI. METHODS: A retrospective study was conducted from January 1, 2000 to December 31, 2017 to identify patients who underwent a DAIR procedure as initial surgical treatment for PJI of the hip or knee. Patients were divided between 2 groups, failed and successful DAIR procedures. Failure was defined as infection recurrence requiring surgical intervention. Demographic (age, gender, body mass index, smoking status, American Society of Anesthesiologists status), preoperative comorbidity (hypertension, cardiac disease, diabetes status, depression or anxiety diagnosis, pulmonary disease), operating surgeon, single vs dual setup, hospital, use of long-term antibiotics postoperatively (greater than 6 weeks of intravenous antibiotics), joint, and laterality data were compared between cohorts using multivariate regression analysis. RESULTS: Two hundred sixty-three patients were identified who underwent DAIR as the exclusive and initial treatment for PJI. Single vs dual setup, knee vs hip joint, cardiac or vascular disease diagnosis, major depressive disorder or generalized anxiety disorder diagnosis, and staphylococcal infections were found to be independent predictive variables for DAIR failure. CONCLUSION: In our series, the dual setup DAIR was a modifiable surgical technique that significantly decreased the risk of infection recurrence compared to single setup DAIR.

Staged vs Concurrent Hardware Removal During Conversion Total Knee Arthroplasty.

BACKGROUND: Conversion total knee arthroplasty (TKA) in the presence of periarticular hardware can be associated with increased resource utilization, complications, and revisions. However, little guidance exists on the optimal approach to hardware removal. The purpose of this study is to compare outcomes of conversion TKA with hardware removal performed in either a staged or concurrent manner. METHODS: This is a retrospective study of 155 TKA operations performed with staged (45) or concurrent (110) removal of hardware at the time of TKA. Differences in patient data, case data, complications, reoperations, and revisions were evaluated. Subgroup comparisons of cases involving major hardware (plates, nails, rods), minor hardware (screws, buttons, wires), and tibial plates were performed. RESULTS: There were no differences in age, sex, body mass index, or comorbidities between patients who underwent staged or concurrent hardware removal. Rates of complications, reoperations, and revisions did not differ at multiple time points (90 days, 1 year, 2 years, 4 years). Patients who underwent staged hardware removal were more likely to have had prior surgery for fracture reconstruction (68% vs 33%, P < .001), to have had major hardware removed (84% vs 59%, P = .03), and were less likely to have had hardware removal performed through a single incision with TKA (50% vs 92%, P < .001). Subgroup analysis of major and minor hardware cases demonstrated comparable outcomes. CONCLUSION: There remains no established benefit to either a staged or concurrent approach to hardware removal at the time of TKA. This is true regardless of hardware burden. At this time, a case-by-case approach should be taken to conversion TKA in the presence of periarticular hardware.

Short-Term Clinical Outcomes of a Conical Prosthesis Used in Revision Total Hip Arthroplasty.

INTRODUCTION: Although primary total hip arthroplasty (THA) stem designs have evolved from conventional lengths to shorter lengths, revision stems have not undergone a similar change. Tapered, conical prostheses have performed well in primary THA, however their use in revision THA has not been thoroughly investigated. Our purpose was to report the short-term radiographic and clinical outcomes of the Wagner Cone Prosthesis® (Zimmer Biomet, Warsaw, Indiana) in revision THA. MATERIALS AND METHODS: An institutional review board approved retrospective study was performed to identify all revision THAs with minimum one-year clinical and radiographic follow up between January 1, 2007 and December 31, 2018, which used a short conical tapered stem to reconstruct the femur. Demographic, surgical, and radiographic variables were collected for each patient. RESULTS: Fifteen hips that fit inclusion criteria were identified. Implant survivorship was 93.3% with a mean follow up of 33.6 months. Radiographic analysis revealed mean subsidence of 2.57mm ± 4.31mm and a limb-length difference of 0.69mm ± 12.4mm longer than the contralateral side. Furthermore, pedestal sign was observed on preoperative radiographs of six patients, none of whom suffered periprosthetic fracture or femoral cortex perforation upon insertion of the conical prosthesis. CONCLUSION: Our findings suggest that the Wagner Cone Prosthesis® is as a useful implant for revision THA. In our sample, it had excellent survivorship, impressive postoperative radiographic measurements obtained from most recent follow up, minimal mean subsidence, and minimal complication rates. Further prospective studies with longer follow up are needed to determine the efficacy of this stem in revision THA.

Comparison of Clinical and Radiological Outcomes of Three Modern Stem Designs in Total Hip Arthroplasty with Minimum Two-Year Follow Up.

INTRODUCTION: Recent changes in stem design for total hip arthroplasty (THA) complicate the daunting task of the orthopaedic surgeon to choose the best stem for patients. The purpose of our study was to report the early- to mid-term clinical and radiological outcomes of three unique stem designs used for THA using primarily a posterolateral approach. MATERIALS AND METHODS: A retrospective study was performed at a single healthcare system between January 2007 and March 2018 to identify THA patients who received a stem belonging to the Taplerloc® Complete Hip System (Zimmer-Biomet, Warsaw, Indiana). Stems were then stratified into full-length, standard profile, full-length, reduced distal profile, and short-length, standard profile cohorts. Demographic, radiological, and clinical outcome variables were collected for each patient and compared between stem cohorts. RESULTS: 538 THAs (248 full-length, reduced distal; 202 full-length, standard profile; 88 short-length, standard profile) were analyzed. One patient in the full-length, reduced distal cohort suffered a perioperative fracture following implantation of the stem. There were a total of 29 postoperative complications at most recent follow up, nine (3.6%) in the full-length, reduced distal group, 12 (5.9%) in the full-length, standard profile group, and eight (9.1%) in the short-length, standard profile group, with no difference in rates of complication between groups (p=0.136). No difference in complication rates was observed when only posterolateral cases were considered (p=0.05). Survivorship of each stem group was 99.6%, 98.5%, and 96.6%, respectively. Limb length discrepancy and stem subsidence were found to be similar between groups based on measurements taken at most recent clinical follow up. CONCLUSION: Our findings suggest that shortened length and reduced distal profile features result in no added benefit regarding intraoperative and postoperative clinical or radiological outcomes.

Can Preoperative Factors Be Used to Determine Optimal Implant Design for Total Knee Arthroplasty?

INTRODUCTION: Although studies have demonstrated similar outcomes between ultracongruent (UC) and traditional bearings, debate exists regarding the optimum bearing surface. We sought to determine whether preoperative factors may predict use of a UC bearing when compared to a standard cruciate retaining (CR) group. MATERIALS AND METHODS: The study cohort consisted of 117 patients who underwent primary total knee arthroplasty (TKA). The implants utilized were either the CR or UC polyethylene components of the Zimmer Persona® Total Knee System. Patient demographics and comorbidities were documented. Intraoperative variables and postoperative outcomes were recorded. We calculated change in tibial slope and femoral condylar offset from pre- to post-surgery and computed the percentage of patients for whom an increase in tibial slope or femoral condylar offset was determined. All dependent variables were compared between patients who received the UC component and those with a CR component using either independent samples t-tests or chi-square test of independence. RESULTS: Thirty-nine patients received a UC insert and 78 patients received a CR insert. Mean length of stay (p=0.017), estimated blood loss (p=0.021), and tourniquet time (p=0.032) were greater for the UC group. Intraoperative implant variables were not different between the groups. However, the proportion of patients for whom tibial slope increased postoperatively was greater for the UC group compared to the CR group (p=0.018). CONCLUSION: Our results showed that no preoperative medical comorbidities or demographic factors predicted use of the UC bearing; however, postoperative tibial slope was increased for a greater number of patients who received the UC implant.

Dual Surgical Setup Associated with Reduced Infection Recurrence for Hip and Knee Arthroplasty After Two-Stage Exchange.

INTRODUCTION: Two-stage exchange (TSE) is the gold standard for the treatment of chronic periprosthetic joint infection (PJI) after total joint arthroplasty of the hip and knee in the United States. Failure of treatment can have devastating consequences for the patient, including poor functional outcomes, multiple further surgeries, and increased mortality. Several factors associated with infection recurrence have previously been identified in the literature. The purpose of this study was to evaluate whether the use of a dual surgical setup was associated with reduced risk of recurrence after TSE for PJI. METHODS: A retrospective study was conducted between January 2000 and December 2021 to isolate patients who underwent TSE after total joint arthroplasty of the hip and knee. Failure was defined as infection recurrence requiring surgical intervention. Demographic factors (age, sex, body mass index, smoking status, American Society of Anesthesiologists status), preoperative comorbidities (hypertension, cardiac disease, diabetes status, depression diagnosis, pulmonary disease), operating surgeon, single versus dual setup, hospital setting, use of long-term antibiotics postoperatively after TSE, aspiration data, and infecting organism were compared between cohorts using multivariate regression analysis. RESULTS: A total of 134 patients were identified who underwent TSE after diagnosis of PJI. The mean follow-up was 67.84 (range, 13 to 236) months. Dual setup (odds ratio, 0.13; confidence interval, 0.02 to 0.52; P = 0.0122) was found to be an independent predictive variable associated with a lower risk of infection recurrence. CONCLUSION: Utilization of a dual surgical setup is a low-cost modifiable risk factor associated with a lower risk of recurrence of after TSE of the hip and knee for PJI.

Peri-Prosthetic Joint Infection in Patients Prescribed Suppressive Antibiotic Therapy Undergoing Primary Total Joint Arthroplasty: A 1:4 Case Control Matched Study.

Background: Oral suppressive antibiotic therapy (SAT) has emerged as a potential means to increase rates of infection-free survival in many complex peri-prosthetic joint infection (PJI) cases after total joint arthroplasty (TJA). The purpose of the present study is to evaluate the risk of PJI of a new primary TJA in patients on oral SAT. Patients and Methods: A retrospective matched cohort study from five hospitals in a 20-year period within a large hospital network was performed. Inclusion criteria consisted of patients over age 18 undergoing primary TJA, with any order for oral long-term (>6 months duration) SAT, and minimum of one-year clinical follow-up. Patients were matched 1:4 on age, gender, body mass index (BMI), hip or knee surgery, diabetes mellitus, smoking status, and indication for primary TJA. Student t-test, Fisher exact, and χ2 tests were utilized for group comparisons. Our study was powered to detect a 10.5% increase in PJI incidence compared with a 1% baseline rate of PJI. Results: We identified 45 TJA in 33 patients receiving SAT, which were matched to 180 control cases. There was no difference in the rate of development of PJI at any time point within follow-up between the SAT cohort and control group (2.22% vs. 1.11%; p = 0.561). Conclusions: We found a 2.22% rate of PJI in a cohort of patients receiving SAT identified over a 20-year period. As the clinical scenario of primary TJA while on SAT is rare but likely to become more prevalent, future large-scale studies can be performed to better clarify rates and risk of PJI in this population.

Development of machine learning algorithms to predict achievement of minimal clinically important difference for the KOOS-PS following total knee arthroplasty.

As cost-effective measures become increasingly implemented in the US healthcare system, changes in patient-reported outcome measure (PROM) scores can be utilized to indicate patient satisfaction following procedures including total knee arthroplasty (TKA). The primary aim of this study was to develop and evaluate machine learning algorithms to predict achievement of the minimal clinically important difference (MCID) for the Knee Injury and Osteoarthritis Outcome Score-Physical Function Short Form (KOOS-PS) at 1-year following TKA. A retrospective review of primary TKA patients between 2016 and 2018 was performed. Variables considered for prediction included demographics and preoperative PROMs. The KOOS-PS MCID was calculated via a distribution-based method. Five machine learning algorithms were developed and tested by discrimination, calibration, Brier score, and decision curve analysis. Among the 744 patients who met the inclusion criteria, 385 (72.8%) patients achieved the MCID. The elastic-net penalized logistic regression model was selected as the best performing model (c-statistic 0.77, calibration intercept -0.02, calibration slope 1.15, and Brier score 0.14). The most important variables for MCID achievement were preoperative KOOS-PS score, preoperative VAS Pain, preoperative opioid use, preoperative PROMIS global mental health score, age, and sex. Algorithms were incorporated into an open-access digital application available at https://sorg-apps.shinyapps.io/tka_koos_mcid/. This study is the first to predict the probability of achieving the KOOS-PS MCID following TKA using a machine learning-based approach. The results were used to develop a clinical decision aid based on commonly collected predictive variables to preoperatively predict an individual patient's likelihood of attaining an acceptable outcome following TKA.