Defining Patient-relevant Thresholds and Change Scores for the HOOS JR and KOOS JR Anchored on the Patient-acceptable Symptom State Question.

BACKGROUND: When evaluating the results of clinical research studies, readers need to know that patients perceive effect sizes, not p values. Knowing the minimum clinically important difference (MCID) and the patient-acceptable symptom state (PASS) threshold for patient-reported outcome measures helps us to ascertain whether our interventions result in improvements that are large enough for patients to care about, and whether our treatments alleviate patient symptoms sufficiently. Prior studies have developed the MCID and PASS threshold for the Hip Disability and Osteoarthritis Outcome Score for Joint Replacement (HOOS JR) and Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS JR) anchored on satisfaction with surgery, but to our knowledge, neither the MCID nor the PASS thresholds for these instruments anchored on a single-item PASS question have been described. QUESTIONS/PURPOSES: (1) What are the MCID (defined here as the HOOS/KOOS JR change score associated with achieving PASS) and PASS threshold for the HOOS JR and KOOS JR anchored on patient responses to the single-item PASS instrument? (2) How do patient demographic factors such as age, gender, and BMI correlate with MCID and PASS thresholds using the single-item PASS instrument? METHODS: Between July 2020 and September 2021, a total of 10,970 patients underwent one primary unilateral THA or TKA and completed at least one of the three surveys (preoperative HOOS or KOOS JR, 1-year postoperative HOOS or KOOS JR, and 1-year postoperative single-item anchor) at one large, academic medical center. Of those, only patients with data for all three surveys were eligible, leaving 13% (1465 total; 783 THAs and 682 TKAs) for analysis. Despite this low percentage, the overall sample size was large, and there was little difference between completers and noncompleters in terms of demographics or baseline patient-reported outcome measure scores. Patients undergoing bilateral total joint arthroplasty or revision total joint arthroplasty and those without all three surveys at 1 year of follow-up were excluded. A receiver operating characteristic curve analysis, leveraging a 1-year, single-item PASS (that is, "Do you consider that your current state is satisfactory?" with possible answers of "yes" or "no") as the anchor was then used to establish the MCID and PASS thresholds among the 783 included patients who underwent primary unilateral THA and 682 patients who underwent primary unilateral TKA. We also explored the associations of age at the time of surgery (younger than 65 years or 65 years and older), gender (men or women), BMI (< 30 or ≥ 30 kg/m 2 ), and baseline Patient-Reported Outcome Measure Information System-10 physical and mental component scores (< 50 or ≥ 50) for each of the MCID and PASS thresholds through stratified analyses. RESULTS: For the HOOS JR, the MCID associated with the PASS was 23 (95% CI 18 to 31), with an area under the receiver operating characteristic curve of 0.75, and the PASS threshold was 81 (95% CI 77 to 85), with an area under the receiver operating characteristic curve of 0.81. For the KOOS JR, the MCID was 16 (95% CI 14 to 18), with an area under the receiver operating characteristic curve of 0.75, and the PASS threshold was 71 (95% CI 66 to 73) with an area under the receiver operating characteristic curve of 0.84. Stratified analyses indicated higher change scores and PASS threshold for younger men undergoing THA and higher PASS thresholds for older women undergoing TKA. CONCLUSION: Here, we demonstrated the utility of a single patient-centered anchor question, raising the question as to whether simply collecting a postoperative PASS is an easier way to measure success than collecting preoperative and postoperative patient-reported outcome measures and then calculating MCIDs and the substantial clinical benefit. LEVEL OF EVIDENCE: Level III, therapeutic study.

High Prevalence of Work-related Musculoskeletal Disorders and Limited Evidence-based Ergonomics in Orthopaedic Surgery: A Systematic Review.

BACKGROUND: The Centers for Disease Control defines work-related musculoskeletal disorders as disorders of the nerves, muscles, tendons, joints, spinal discs, and cartilage that are caused or exacerbated by the environment or nature of work. Previous meta-analyses have characterized work-related musculoskeletal disorders among interventionists, general surgeons, and other surgical subspecialties, but prevalence estimates, prognosis, and ergonomic considerations vary by study and surgical specialty. QUESTIONS/PURPOSES: (1) What is the career prevalence of work-related musculoskeletal disorders in orthopaedic surgeons? (2) What is the treatment prevalence associated with work-related musculoskeletal disorders in orthopaedic surgeons? (3) What is the disability burden of work-related musculoskeletal disorders in orthopaedic surgeons? (4) What is the scope of orthopaedic surgical ergonomic assessments and interventions? METHODS: A systematic review of English-language studies from PubMed, MEDLINE, Embase, and Scopus was performed in December 2022 and reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Studies that presented prevalence estimates of work-related musculoskeletal disorders or assessed surgical ergonomics in orthopaedic surgery were included. Reviews, case reports, gray literature (conference abstracts and preprints), and studies with mixed-surgeon (nonorthopaedic) populations were excluded. The search yielded 5603 abstracts; 24 survey-based studies with 4876 orthopaedic surgeons (mean age 48 years; 79% of surgeons were men) were included for an analysis of work-related musculoskeletal disorders, and 18 articles were included for a descriptive synthesis of ergonomic assessment. Quality assessment using the Joanna Briggs Institute Tool revealed that studies had a low to moderate risk of bias, largely because of self-reporting survey-based methodology. Because of considerable heterogeneity and risk of bias, prevalence outcomes were not pooled and instead are presented as ranges (mean I 2 = 91.3%). RESULTS: The career prevalence of work-related musculoskeletal disorders in orthopaedic surgeons ranged from 37% to 97%. By anatomic location, the prevalence of work-related musculoskeletal disorders in the head and neck ranged from 4% to 74%; back ranged from 9% to 77%; forearm, wrist, and hand ranged from 12% to 54%; elbow ranged from 3% to 28%; shoulder ranged from 3% to 34%; hip and thigh ranged from 1% to 10%; knee and lower leg ranged from 1% to 31%; and foot and ankle ranged from 4% to 25%. Of orthopaedic surgeons reporting work-related musculoskeletal disorders, 9% to 33% had a leave of absence, practice restriction or modification, or early retirement, and 27% to 83% received some form of treatment. Orthopaedic surgeons experienced biomechanical, cardiovascular, neuromuscular, and metabolic stress during procedures. Interventions to improve orthopaedic surgical ergonomics have been limited, but have included robotic assistance, proper visualization aids, appropriate use of power tools, and safely minimizing lead apron use. In hip and knee arthroplasty, robotic assistance was the most effective in improving posture and reducing caloric expenditure. In spine surgery, proper use of surgical loupes was the most effective in improving posture. CONCLUSION: Although the reported ranges of our main findings were wide, even on the low end of the reported ranges, work-related musculoskeletal disability among orthopaedic surgeons appears to be a substantial concern. We recommend that orthopaedic residency training programs incorporate surgical ergonomics or work injury lectures, workshops, and film review (alongside existing film review of surgical skills) into their curricula. We suggest hospitals engage in shared decision-making with surgeons through anonymous needs assessment surveys to implement wellness programs specific to surgeons' musculoskeletal needs. We urge institutions to assess surgeon ergonomics during routine quality assessment of novel surgical instruments and workflows. LEVEL OF EVIDENCE: Level III, prognostic study.

Should We Wait for Bone-on-Bone Arthritis? Equivalent Clinical Outcomes in Patients Requiring Advanced Imaging Before Primary Total Hip Arthroplasty.

BACKGROUND: Plain radiographs remain the standard for diagnosing osteoarthritis (OA). Total hip arthroplasty (THA) is generally offered only for advanced OA by plain radiographs. Advanced imaging is used as an adjunct to assess OA severity in cases of progressive symptoms with less advanced OA by plain radiographs. The objective of this study was to compare outcomes following THA in patients who have advanced OA visualized by plain radiographs to patients who have less severe OA visualized by plain radiographs. METHODS: From February 2016 to February 2020, 93 patients who had Kellgren-Lawrence (KL) grade 0 to 2 OA and underwent THA were identified. The median age was 65 years, and 55% were women. They were matched 1:3 to patients who underwent THA for KL 4 OA based on age, sex, body mass index, and Charlson Comorbidity Index. The primary outcome was achievement of the Hip Injury and Osteoarthritis Outcome Score for Joint Replacement (HOOS JR) minimum clinically important difference, substantial clinical benefit, and patient-acceptable symptom state at 1 year postoperatively. RESULTS: There was no difference between the KL 0 to 2 and KL 4 cohorts in the achievement of HOOS JR minimum clinically important difference (86 versus 85.6%, P = .922), substantial clinical benefit (81.7 versus 80.2%, P = .751), or patient-acceptable symptom state (89.2 versus 85.6%, P = .374). The KL 0 to 2 cohort had a similar improvement in their 2-year HOOS JR (42.5 versus 38.6, P = .019). CONCLUSIONS: In this series, there was no difference in outcomes following primary THA between patients who have severe OA on plain radiographs (KL 4) compared to those who have less severe OA (KL 0 to 2). In the setting of severe symptoms and the absence of advanced OA on radiographs, advanced imaging can be used to guide treatment and select patients who could benefit from THA.

Does Approach Matter in Robotic-Assisted Total Hip Arthroplasty? A Comparison of Early Reoperations Between Direct Anterior and Postero-Lateral Approach.

BACKGROUND: There is no consensus on whether direct anterior approach (DAA) or postero-lateral approach (PLA) total hip arthroplasty (THA) confers a lower risk of postoperative complications. Robotic assistance in THA results in a more consistently accurate component position compared to manual THA. The objective of this study was to compare rates of dislocation, reoperation, revision, and patient-reported outcome measures between patients undergoing DAA and PLA robotic-assisted primary THA. METHODS: We identified 2,040 consecutive robotic-assisted primary THAs performed for primary osteoarthritis, using DAA (n = 497) or PLA (n = 1,542) between 2017 and 2020. The mean follow-up was 18 months. Kaplan-Meier analysis estimated survivorship free of dislocation, reoperation, and revision. Achievement of patient acceptable symptom state and minimum clinically important difference were used to compare changes in the Hip Disability and Osteoarthritis Outcome Score, Joint Replacement (HOOS JR) and Visual Analog Scale. RESULTS: Dislocation was rare in this series (14 in 2,040, 0.7%), including 1 of 497 (0.2%) in the DAA cohort and 13 of 1,542 (0.8%) in the PLA cohort (P = .210). There was no difference in 2-year reoperation-free survivorship (97.8 versus 98.6%, P = .59) or revision-free survivorship (98.8 versus 99.0%, P = .87) at any time point. After controlling for age, sex, and body mass index, there was no difference in dislocation, reoperation, or revision. At 6-week follow-up, after controlling for age, sex, and body mass index, patients in the DAA cohort had higher odds of achieving HOOS JR minimum clinically important difference (odds ratio = 2.01, P = .012) and HOOS JR patient acceptable symptom state (odds ratio = 1.72, P = .028). There were no differences in patient-reported outcome measures by 3 months. CONCLUSIONS: For robotic-assisted primary THA, DAA may confer enhanced early (<6 weeks) functional recovery compared to the PLA, but there was no significant difference in postoperative dislocation, reoperation, or revision rates.

A Comparison of Clinical Outcomes After Total Knee Arthroplasty in Patients Who Have and Do Not Have Self-Reported Nickel Allergy: Matched and Unmatched Cohort Comparisons.

BACKGROUND: The impact of a preoperative self-reported nickel allergy in patients undergoing primary total knee arthroplasty (TKA) remains unclear. The aim of this study was to compare the revision rates and outcomes of patients who have a self-reported nickel allergy undergoing primary TKA to patients who do not have a self-reported nickel allergy. METHODS: Over 5 years, a total of 284 TKAs in patients who have and 17,735 in patients who do not have a self-reported nickel allergy were performed. Revision rates and differences in preoperative and postoperative patient-reported outcome measures, including Knee Osteoarthritis Outcome Score Joint Replacement (KOOS JR), Visual Analog Scale, Lower Extremity Activity Scale, and the Patient-Reported Outcomes Measurement Information System Mental and Physical Scores, were compared. RESULTS: Survivorship free of all-cause revision at 1 year was similar for patients who have and do not have a self-reported nickel allergy (99.5% [95% CI (confidence interval): 98.6 to 100.0] versus 99.3% [95% CI: 99.1 to 99.4]), P = .49). Patients who have a self-reported nickel allergy undergoing primary TKA had no difference in KOOS JR, Visual Analog Scale, or Lower Extremity Activity Scale scores at 6 weeks and 1 year and slightly worse Patient-Reported Outcomes Measurement Information System mental and physical scores at 6 weeks compared to patients who did not have an allergy. Matched analysis revealed no difference in 6-week or 1-year KOOS, JR scores between patients who did and did not have a self-reported nickel allergy when stratified by implant class (nickel-free versus standard cobalt-chromium) (P = .113 and P = .415, respectively). CONCLUSIONS: Patients who have a self-reported nickel allergy can be advised that, on average, their clinical outcome scores will improve similarly to patients who do not have a self-reported nickel allergy, and revision rates will be similar.

Metrics of Clinically Important Changes in Total Hip Arthroplasty: A Systematic Review.

BACKGROUND: Although patient-reported outcome measures (PROMs) have become a regularly used metric, there is little consensus on the methodology used to determine clinically relevant postoperative outcomes. We systematically reviewed the literature for studies that have identified metrics of clinical efficacy after total hip arthroplasty (THA) including minimal clinically important difference (MCID), patient acceptable symptom state (PASS), minimal detectable change (MDC), and substantial clinical benefit (SCB). METHODS: A systematic review examining quantitative metrics for assessing clinical improvement with PROMs following THA was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines using the MEDLINE database from 2008 to 2020. Inclusion criteria included full texts, English language, primary THA with minimum 1-year follow-up, use of metrics for assessing clinical outcomes with PROMs, and primary derivations of those metrics. Sixteen studies (24,487 THA patients) met inclusion criteria and 11 different PROMs were reported. RESULTS: MCIDs were calculated using distribution methods in 7 studies (44%), anchor methods in 2 studies (13%), and both methods in 2 studies (13%). MDC was calculated in 2 studies, PASS was reported in 1 study using anchor-based method, and SCB was calculated in 1 study using anchor-based method. CONCLUSION: There is a lack of consistency in the literature regarding the use and interpretation of PROMs to assess patient satisfaction. MCID was the most frequently reported measure, while MDC, SCB, and PASS were used relatively infrequently. Method of derivation varied based on the PROM used; distribution method was more frequently used for MCID.

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.

The Influence of Dorr Type and Femoral Fixation on Outcomes Following Total Hip Arthroplasty for Acute Femoral Neck Fractures: A Multicenter Study.

BACKGROUND: The American Academy of Orthopaedic Surgeons guidelines report moderate evidence for cementing femoral stems for hip fractures, mainly derived from hemiarthroplasty literature. This is the first large, nonregistry study examining the influence of femoral fixation, implant type, patient characteristics, and radiographic factors on outcomes after total hip arthroplasty (THA) for acute femoral neck fractures. METHODS: A multicenter retrospective study was performed of 709 THA cases (199 cemented, 510 cementless) for femoral neck fractures from 2006 to 2020 at three large academic institutions. Demographics, perioperative characteristics, and radiographs were reviewed. Kaplan-Meier survivorship curves were generated for multiple outcomes. Univariate and multivariate analyses were performed with P ≤ .05 denoting significance. RESULTS: Cementless stems had a higher all-cause aseptic femoral revision rate (5.1 versus 0.5%, P = .002) and periprosthetic femoral fracture rate (4.3 versus 0%, P = .001). Each successive Dorr type had a higher fracture rate with cementless implants: 2.3%, 3.7%, and 15.9% in Dorr A, B, and C, respectively (P < .001). Logistic regression analyses confirmed that cementless stems (P = .02) and Dorr C bone (P = .001) are associated with periprosthetic fractures; collared implants and prophylactic cables did not protect against fractures. There was no difference in rates of dislocation, septic revision, or mortality between groups. CONCLUSION: Cementless stems during THA for femoral neck fractures have a higher aseptic femoral revision rate, specifically for periprosthetic fractures. Dorr C bone was particularly prone with an alarmingly high fracture rate. All fractures occurred in cementless cases, suggesting that cemented stems may minimize this complication. LEVEL OF EVIDENCE: III.

A Comparison of Clinical Outcomes After Total Knee Arthroplasty in Patients With Preoperative Nickel Allergy Receiving Cobalt Chromium or Nickel-Free Implant.

BACKGROUND: The role of metal hypersensitivity reactions in total knee arthroplasty (TKA) failure is debated. There is no consensus on whether use of a more expensive nickel-free implant is indicated for patients who have preoperative nickel allergy. The purpose of this study was to examine the outcome of patients who have preoperative nickel allergy receiving nickel-free or cobalt chromium (CoCr) implants. METHODS: This was a retrospective review of 17,798 patients who underwent 20,324 unilateral primary TKAs between 2016 and 2020. Presence of preoperative nickel allergy was determined (n = 282). Patients were divided into 2 cohorts: those receiving (1) nickel-free or (2) CoCr implants. Clinical outcome scores and revision rates were assessed. RESULTS: 243 received a nickel-free implant and 39 received a CoCr implant. There was no significant difference in revision rate between the cohorts. Survivorship free of revision was 94% in the CoCr implant cohort and 98% in the nickel-free implant cohort (P = .9). When comparing clinical outcome scores between cohorts, there was no difference in preoperative, 6-week or 1-year Knee Osteoarthritis Outcome Score Joint Replacement, Visual Analog Scale (VAS), Lower Extremity Activity Scale, Patient-Reported Outcomes Measurement Information System (PROMIS), and Veterans RAND 12-item scores between cohorts. CONCLUSION: In this retrospective cohort study, there was no difference in revision rates or clinical outcomes in patients who had a nickel allergy undergoing primary TKA with CoCr or nickel-free implants. Further studies are needed to determine if nickel allergy is an independent risk factor for worse TKA outcomes in general.

Effect of anterior approach compared to posterolateral approach on readiness for discharge and thrombogenic markers in patients undergoing unilateral total hip arthroplasty: a prospective cohort study.

INTRODUCTION: The direct anterior approach (DAA) for total hip arthroplasty (THA) is considered less invasive than the posterolateral approach (PLA), possibly leading to earlier mobilization, faster recovery, and lower levels of thrombogenic markers. The purpose of the current study was to prospectively compare readiness for discharge, rehabilitation milestones, markers of thrombosis and inflammation at 6 weeks postoperatively between DAA and PLA. METHODS: A total of 40 patients (20 anterior and 20 posterolateral) were prospectively enrolled. Readiness for discharge, length of stay (LOS), and related outcomes were additionally documented. Blood was drawn at baseline, wound closure, 5-h post-closure, and 24-h post-closure for assays of interleukin-6 (IL-6), PAP (plasmin anti-plasmin), a marker of fibrinolysis, and PF1.2 (Prothrombin fragment 1.2), a marker of thrombin generation. RESULTS: Compared to the PLA group, the DAA group was ready for discharge a mean 13 h earlier (p = 0.03), while rehabilitation milestones were met a mean 10 h earlier (p = 0.04), and LOS was 13 h shorter (p = 0.02) on average. Pain scores at all study timepoints and patient satisfaction at 6 weeks were similar (p > 0.05). At 24 h postoperatively, PAP levels were 537.53 ± 94.1 µg/L vs. 464.39 ± 114.6 µg/L (p = 0.05), and Il-6 levels were 40.94 ± 26.1 pg/mL vs. 60.51 ± 33.0 pg/mL (p = 0.03), in DAA vs. PLA, respectively. CONCLUSIONS: In the immediate postoperative period, DAA patients were ready for discharge before PLA patients. DAA patients had shorter LOS, a lower inflammatory response, and higher systemic markers of fibrinolysis. However, these differences may not be clinically significant. Future studies with larger study populations are warranted to confirm the validity and significance of these findings. LEVEL OF EVIDENCE: Level II, Therapeutic Study.

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.

Development and Validation of Crosswalks Between the Western Ontario & McMaster Universities Osteoarthritis Index and Hip Disability and Osteoarthritis Outcome Score Joint Replacement/Knee Injury and Osteoarthritis Outcome Score Joint Replacement.

BACKGROUND: The wide variety of patient-reported outcome measures used to assess outcomes following total joint arthroplasty can present a substantial methodological obstacle when attempting to compare information across studies or between institutions. A simple solution is to create crosswalks that reliably convert scores between patient-reported outcome measures. Our goal is to create and validate crosswalks between the commonly used Western Ontario & McMaster Universities Osteoarthritis Index (WOMAC) and short-form versions of the Hip Disability and Osteoarthritis Outcome Score Joint Replacement (HOOS JR)/Knee Injury and Osteoarthritis Outcome Score (KOOS JR.). METHODS: Patients in our joint replacement registry were included if they underwent primary total hip arthroplasty (n = 4649) or total knee arthroplasty (n = 3750) for osteoarthritis between May 2007 and February 2012. We used their preoperative and 2-year postoperative HOOS scores (n = 6351) or KOOS scores (n = 4688) to generate the patients' WOMAC and HOOS JR/KOOS JR scores. The equipercentile equating method was applied to create 10 crosswalks: HOOS JR/KOOS JR to WOMAC Total (WOMAC-T), and WOMAC-T, WOMAC Pain (WOMAC-P), WOMAC Stiffness (WOMAC-S), and WOMAC Function (WOMAC-F) to HOOS JR/KOOS JR. Crosswalk validity was assessed by comparing actual and derived scores using Spearman's rank correlation coefficients in a bootstrapped cohort. RESULTS: All 10 crosswalks showed strong positive correlations ranging from 0.846 (WOMAC-S to KOOS JR) to 0.981 (HOOS JR to WOMAC-T). CONCLUSION: We created and validated 10 crosswalks between WOMAC and HOOS JR/KOOS JR. We recommend using the crosswalks between WOMAC-T and HOOS JR/KOOS JR when possible, as they demonstrated the highest correlation. WOMAC-F or WOMAC-P should be used in favor of WOMAC-S if only subscores are available. The HOOS JR/KOOS JR should only be converted to a WOMAC-T. LEVEL OF EVIDENCE: Level III.

Patient and Surgeon Risk-Taking Regarding Total Joint Arthroplasty.

BACKGROUND: Decisions regarding care for osteoarthritis involve physicians helping patients understand likely benefits and harms of treatment. Little work has directly compared patient and surgeon risk-taking attitudes, which may help inform strategies for shared decision-making and improve patient satisfaction. METHODS: We surveyed patients contemplating total joint arthroplasty visiting a high-volume specialty hospital regarding general questions about risk-taking, as well as willingness to undergo surgery under hypothetical likelihoods of moderate improvement and complications. We compared responses from surgeons answering similar questions about willingness to recommend surgery. RESULTS: Altogether 82% (162/197) of patients responded, as did 65% (30/46) of joint replacement surgeons. Mean age among patients was 66.4 years; 58% were female. Surgeons averaged 399 surgeries in 2019. Responses were similar between groups for general, health, career, financial, and sports/leisure risk-taking (P > .20); surgeons were marginally more risk-taking in driving (P = .05). For willingness to have or recommend surgery, as the chance of benefit decreased, or the chance of harm increased, the percentage willing to have or recommend surgery decreased. Between a 70% and 95% chance of moderate improvement (for a 2% complication risk), as well as between a 90% and 95% chance of moderate improvement (for 4% and 6% complication risks), the percentage willing to have or recommend surgery was indistinguishable between patients and surgeons. However, for lower likelihoods of improvement, a higher percentage of patients were willing to undergo surgery than surgeons recommended. Patients were also more often indifferent between complication risks. CONCLUSION: Although patients and surgeons were often willing to have or recommend joint replacement surgery at similar rates, they diverged for lower-benefit higher-harm scenarios.

Nonconcentric and Irregular Dislocations of Total Hip Arthroplasties: Radiographic Analysis and Review of the Literature.

BACKGROUND: Total hip arthroplasty (THA) is one of the most successful operations in all of medicine in improving patient pain and restoring function. However, complications do arise after primary and revision THA. Dislocation of a THA, also known as instability, occurs in 1-2% of primary THAs and up to 30% of revision THAs. Most dislocations in the United States are initially managed with closed reduction under procedural sedation in emergency departments (EDs) by on-call orthopedists or emergency medicine specialists. OBJECTIVE: In this review the characteristics of the articulations that may require closed reduction in the ED are described, as well as their radiographic findings prior to reduction. Finally, we present subtle radiographic findings associated with failed closed reductions. DISCUSSION: Due to the different types of implants that have been introduced, closed reduction can be challenging in certain cases. Iatrogenic intraprosthetic dislocations are becoming more common with the increased use of dual-mobility liners. There are also dislocations after staged revision THA cases with the use of spacers. In spacers with semi-constrained articulation, there is the possibility of partial reduction of the spacer. CONCLUSIONS: Dislocation is one of the most common mechanical complications after primary and revision THA. In the majority of the cases, acute closed reduction can be achieved successfully in the ED setting. However, there are specific dislocation types that present unique challenges to acute reduction.

EOS Imaging is Accurate and Reproducible for Preoperative Total Hip Arthroplasty Templating.

BACKGROUND: Templating is a critical part of preoperative planning for total hip arthroplasty (THA). The accuracy of templating on images acquired with EOS is unknown. This study sought to compare the accuracy and reproducibility of templating for THA using EOS imaging to conventional digital radiographs. METHODS: Forty-three consecutive primary unilateral THAs were retrospectively templated, six months postoperatively, using preoperative 2D EOS imaging and conventional radiographs. Two blinded observers templated each case for acetabular and femoral component size and femoral offset. The retrospectively templated sizes were compared to the sizes selected during surgery. Interobserver agreement was calculated, and the influence of demographic variables was explored. RESULTS: EOS templating predicted the exact acetabular and femoral size in 71% and 66% of cases, respectively, and to within one size in 98% of cases. The acetabular and femoral component size was more likely to be templated to the exact size using EOS compared to conventional imaging (P < .05). The femoral component offset choice was accurately predicted in 83% of EOS cases compared to 80% of conventional templates (P = .341). Component size and offset were not influenced by patient age, gender, laterality, or BMI. Interobserver agreement was excellent for acetabular (Cronbach's alpha = 0.94) and femoral (Cronbach's alpha = 0.96) component size. CONCLUSIONS: Preoperative templating for THA using EOS imaging is accurate, with an excellent interobserver agreement. EOS exposes patients to less radiation than traditional radiographs, and its three-dimensional applications should be explored as they may further enhance preoperative plans.

Projected Economic Burden of Periprosthetic Joint Infection of the Hip and Knee in the United States.

BACKGROUND: In addition to the significant morbidity and mortality associated with periprosthetic joint infection (PJI), the cost of treating PJI is substantial. Prior high-quality national estimates of the economic burden of PJI utilize data up to 2009 to project PJI growth in the United States through 2020. Now in the year 2020, it is appropriate to evaluate these past projections and incorporate the latest available data to better understand the current scale and burden of PJI in the United States. METHODS: The Nationwide Inpatient Sample (2002-2017) was used to identify rates and associated inpatient costs for primary total knee arthroplasty (TKA) and total hip arthroplasty (THA) and PJI-related revision TKA and THA. Poisson regression was utilized to model past growth and project future rates and cost of PJI of the hip and knee. RESULTS: Using the most recent data, the combined annual hospital costs related to PJI of the hip and knee were estimated to be $1.85 billion by 2030. This includes $753.4 million for THA PJI and $1.1 billion for TKA PJI, in that year. Increases in PJI costs are mainly attributable to increases in volume. Although the growth in incidence of primary THA and TKA has slowed in recent years, the incidence of PJI and the cost per case of PJI remained relatively constant from 2002 to 2017. DISCUSSION: Understanding the current and potential future financial burden of PJI for surgeons, patients, and healthcare systems is essential. There is an urgent need for efficacious preventive strategies in reducing rates of PJI after THA and TKA.

Presenteeism and Absenteeism Before and After Total Hip and Knee Arthroplasty.

BACKGROUND: Absenteeism is costly, yet evidence suggests that presenteeism-illness-related reduced productivity at work-is costlier. We quantified employed patients' presenteeism and absenteeism before and after total joint arthroplasty (TJA). METHODS: We measured presenteeism (0-100 scale, 100 full performance) and absenteeism using the World Health Organization's Health and Work Performance Questionnaire before and after TJA among a convenience sample of employed patients. We captured detailed information about employment and job characteristics and evaluated how and among whom presenteeism and absenteeism improved. RESULTS: In total, 636 primary, unilateral TJA patients responded to an enrollment email, confirmed employment, and completed a preoperative survey (mean age: 62.1 years, 55.3% women). Full at-work performance was reported by 19.7%. Among 520 (81.8%) who responded to a 1-year follow-up, 473 (91.0%) were still employed, and 461 (88.7%) had resumed working. Among patients reporting at baseline and 1 year, average at-work performance improved from 80.7 to 89.4. A Wilcoxon signed-rank test indicated that postoperative performance was significantly higher than preoperative performance (P < .0001). The percentage of patients who reported full at-work performance increased from 20.9% to 36.8% (delta = 15.9%, 95% confidence interval = [10.0%, 21.9%], P < .0001). Presenteeism gains were concentrated among patients who reported declining work performance leading up to surgery. Average changes in absences were relatively small. Combined, the average monthly value lost by employers to presenteeism declined from 15.3% to 8.3% and to absenteeism from 16.9% to 15.5% (ie, mitigated loss of 8.4% of monthly value). CONCLUSION: Among employed patients before TJA, presenteeism and absenteeism were similarly costly. After, employed patients reported increased performance, concentrated among those with declining performance leading up to surgery.

The Short Form KOOS, JR Is Valid for Revision Knee Arthroplasty.

BACKGROUND: The Knee Injury Osteoarthritis Outcome Survey, Joint Replacement (KOOS, JR) is a reliable, responsive, and validated patient-reported outcome measure (PROM) of knee health in patients with knee osteoarthritis undergoing unilateral primary total knee arthroplasty (TKA). The validity of the KOOS, JR for revision TKA remains unknown. METHODS: We identified 314 patients who underwent revision TKA and had completed preoperative and 2-year postoperative PROMs. Validation included assessment of local dependence, unidimensionality, internal consistency, external construct validity, responsiveness, and floor effects preoperatively and ceiling effects at 2 years postoperatively. RESULTS: Among patients undergoing revision TKA, the KOOS, JR demonstrated an absence of residual item correlation, adequate unidimensionality, high internal consistency (Person Separation Index: 0.897), and high external construct validity with existing validated PROMs, including KOOS Pain (Spearman's correlation coefficient 0.89) and KOOS activities of daily living (0.90) domains. The KOOS, JR was more responsive (standardized response means: 1.14) to revision TKA than other common knee PROMs. Three percent of revision TKA patients were at the floor (lowest score) preoperatively and 9% reached the ceiling (highest possible score) postoperatively. CONCLUSIONS: KOOS, JR performs well in revision TKA patients with regard to internal consistency, external validity, responsiveness, and floor and ceiling effects. Our results support extending its use to revision TKA in both clinical and research settings.

Primary Total Knee Arthroplasty Performed Using High-Viscosity Cement is Associated With Higher Odds of Revision for Aseptic Loosening.

BACKGROUND: Aseptic loosening (AL) is the most common reason for revision total knee arthroplasty (TKA). An association between high-viscosity cement (HVC) and AL has been suggested by small, uncontrolled, case series. This study sought to determine whether HVC use during primary TKA is independently associated with AL requiring revision. METHODS: We retrospectively analyzed a prospectively collected institutional knee registry to identify all primary TKAs from January 2007 to December 2016. Patients with less than 2 years of follow-up were excluded. Cement type was divided into 2 groups: HVC and low-viscosity cement. Potential confounders including age, body mass index, preoperative diagnosis, antibiotics in the cement, and implant type were recorded. Multivariable logistic regression analysis was used to determine whether HVC is independently associated with revision for AL. RESULTS: In total, 10,014 patients were included. Revision for AL was significantly higher in the HVC cohort (91/4790; 1.9%) vs the low-viscosity cement cohort (48/5224; 0.92%) (P < .001). Logistic regression demonstrated HVC to be independently associated with higher odds of revision for AL (odds ratio 2.26, 95% confidence interval 1.58-3.22, P < .001). Younger age was also associated with higher odds of revision for AL (odds ratio 0.96, 95% confidence interval 0.94-0.98, P < .001). Body mass index, gender, laterality, preoperative diagnosis, and antibiotics in the cement were not associated with revision for AL. Implant manufacturer, implant design, and cement brand all impacted the odds of undergoing revision for AL. CONCLUSION: Although HVC is an attractive option for use in primary TKA, this appropriately controlled study demonstrates higher odds of revision for AL when using HVC with multiple different implant types.

Bariatric Surgery Prior to Total Hip Arthroplasty Is Cost-Effective in Morbidly Obese Patients.

BACKGROUND: The cost-effectiveness of bariatric surgery to achieve weight loss prior to total hip arthroplasty (THA), and decrease the complications and costs associated with THA in the morbidly obese, is unknown. This study evaluated the cost-effectiveness of bariatric surgery prior to THA for morbidly obese patients with end-stage hip osteoarthritis (OA). METHODS: A state-transition Markov model was constructed to compare the cost-utility of 2 treatment protocols for patients with morbid obesity and end-stage hip OA: (1) immediate THA and (2) bariatric surgery 2 years prior to THA (combined protocol). The analysis was performed from both a payer and a societal perspective using direct and indirect costs over a 40-year time horizon. Utilities, associated costs, and probabilities for health state transitions were derived from the literature. One-way, 2-way and probabilistic sensitivity analyses were performed to validate the robustness of the base case results, using the standard willingness-to-pay threshold of $100,000/quality-adjusted life years. RESULTS: From the societal perspective, the combined protocol was more effective (13.16 vs 12.26) with less cost ($91,717 vs $92,684) and thus was the dominant strategy over immediate THA. These results were stable across broad ranges for independent model variables. Monte Carlo simulation with 100,000 samples demonstrated that bariatric surgery prior to THA was the preferred cost-effective strategy over 95% of the time from both a societal and payer perspective. CONCLUSION: In the morbidly obese patient with end-stage hip OA, bariatric surgery prior to THA is a cost-effective strategy for improving quality of life and decreasing societal and payer costs. LEVEL OF EVIDENCE: II.