Time to Achieve the Minimal Clinically Important Difference in Primary Total Hip Arthroplasty: Comparison of Anterior and Posterior Surgical Approaches.

BACKGROUND: Controversy remains over outcomes between total hip arthroplasty approaches. This study aimed to compare the time to achieve the minimal clinically important difference (MCID) for the Hip Disability and Osteoarthritis Outcome Score-Physical Function Short Form (HOOS-PS) and the Patient-Reported Outcomes Measurement Information System (PROMIS) Global-Physical for patients who underwent anterior and posterior surgical approaches in primary total hip arthroplasty. METHODS: Patients from 2018 to 2021 with preoperative and postoperative HOOS-PS or PROMIS Global-Physical questionnaires were grouped by approach. Demographic and MCID achievement rates were compared, and survival curves with and without interval-censoring were used to assess the time to achieve the MCID by approach. Log-rank and weighted log-rank tests were used to compare groups, and Weibull regression analyses were performed to assess potential covariates. RESULTS: A total of 2,725 patients (1,054 anterior and 1,671 posterior) were analyzed. There were no significant differences in median MCID achievement times for either the HOOS-PS (anterior: 5.9 months, 95% confidence interval [CI]: 4.6 to 6.4; posterior: 4.4 months, 95% CI: 4.1 to 5.1, P = .65) or the PROMIS Global-Physical (anterior: 4.2 months, 95% CI: 3.5 to 5.3; posterior: 3.5 months, 95% CI: 3.4 to 3.8, P = .08) between approaches. Interval-censoring revealed earlier times of achieving the MCID for both the HOOS-PS (anterior: 1.509 to 1.511 months; posterior: 1.7 to 2.3 months, P = .87) and the PROMIS Global-Physical (anterior: 3.0 to 3.1 weeks; posterior: 2.7 to 3.3 weeks, P = .18) for both surgical approaches. CONCLUSIONS: The time to achieve the MCID did not differ by surgical approach. Most patients will achieve clinically meaningful improvements in physical function much earlier than previously believed. LEVEL OF EVIDENCE: Level III, Retrospective Comparative Study.

AAHKS Surgical Techniques & Technologies Award: Inferior Screw Fixation Decreases Acetabular Component Failure Following Revision Total Hip Arthroplasty.

BACKGROUND: Adjunctive screw fixation has been shown to be reliable in achieving acetabular component stability in revision total hip arthroplasty (THA). The purpose of this study was to assess the effect of inferior screw placement on acetabular component failure following revision THA. We hypothesized that inferior screw fixation would decrease acetabular failure rates. METHODS: We reviewed 250 patients who had Paprosky Type II or III defects who underwent acetabular revision between 2001 and 2021 across three institutions. Demographic factors, the number of screws, location of screw placement (superior versus inferior), use of augments and/or cup-cage constructs, Paprosky classification, and presence of discontinuity were documented. Multivariate regression was performed to identify the independent effect of inferior screw fixation on the primary outcome of aseptic rerevision of the acetabular component. RESULTS: At a mean follow-up of 53.4 months (range, 12 to 261), 16 patients (6.4%) required re-revision for acetabular loosening. There were 140 patients (56.0%) who had inferior screw fixation, all of whom did not have neurovascular complications during screw placement. Patients who had inferior screws had a lower rate of acetabular rerevision than those who only had superior screw fixation (2.1 versus 11.8%, P = .0030). Multivariate regression demonstrates that inferior screw fixation decreased the likelihood of rerevision for acetabular loosening when compared to superior screw fixation alone (odds ratio: 0.1, confidence interval: 0.03 to 0.5; P = .0071). No other risk factors were identified. CONCLUSIONS: Inferior screw fixation is a safe and reliable technique to reduce acetabular component failure following revision THA in cases of severe acetabular bone loss.

Diagnostic Test Performances for Identifying Periprosthetic Joint Infection in Hip Hemiarthroplasty.

INTRODUCTION: Periprosthetic joint infection (PJI) is a devastating complication of hip hemiarthroplasty (HHA) that is not well-represented in the literature. Therefore, this study aimed to evaluate diagnostic markers for identifying PJI in patients after HHA and compare them with the most recent 2018 International Consensus Meeting on Musculoskeletal Infection criteria. METHODS: A total of 98 patients (64 PJIs, 65.3%) were analyzed. Patients were identified by relevant Current Procedural Terminology and International Classification of Diseases-9/10 codes from 2000 to 2021 across a single healthcare system. Preoperative or intraoperative synovial fluid nucleated cell (NC) count, synovial polymorphonuclear (PMN) percentage, serum erythrocyte sedimentation rate (ESR), serum C-reactive protein (CRP), and serum white blood cell count were compared with Student t -test between aseptic and septic cohorts. Diagnostic utility and laboratory cutoff values were determined using receiver-operating characteristic curves and Youden index, respectively. RESULTS: Mean values were significantly higher in the septic cohort for synovial NC count (120,992.2 versus 1,498.0 cells/µL, P < 0.001), synovial PMN percentage (91.3% versus 56.2%, P < 0.001), serum ESR (75.6 versus 36.3 mm/hr, P < 0.001), serum CRP (20.2 versus 125.8 mg/L, P < 0.001), and serum white blood cell count (8.5 versus 11.5 cells/µL, P < 0.001). Synovial NC count, synovial PMN percentage, and serum CRP had excellent PJI discriminatory ability with an area under the curve of 0.99, 0.90, and 0.93, respectively. Optimal cutoffs were 2,700 cells/µL for synovial NC count (100% sensitivity and 94% specificity), 81.0% for synovial PMN percentage (96% sensitivity and 89% specificity), 52.0 mm/hr for serum ESR (75% sensitivity and 80% specificity), and 40.0 mg/L for serum CRP (85% sensitivity and 92% specificity). CONCLUSION: Our findings support the continued use of routine serum and synovial fluid tests for diagnosing PJI in HHA patients. Optimal cutoff values for both synovial fluid biomarkers were very close in alignment with the 2018 International Consensus Meeting criteria. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Mental Health Effects on the Minimal Clinically Important Difference in Total Joint Arthroplasty.

INTRODUCTION: The effect of mental health on patient-reported outcome measures is not fully understood in total joint arthroplasty (TJA). Thus, we investigated the relationship between mental health diagnoses (MHDs) and the Minimal Clinically Important Difference for Improvement (MCID-I) and Worsening (MCID-W) in primary TJA and revision TJA (rTJA). METHODS: Retrospective data were collected using relevant Current Procedural Terminology and MHDs International Classification of Diseases, 10th Revision, codes with completed Hip Disability and Osteoarthritis Outcome Score-Physical Function Short Form, Knee Injury and Osteoarthritis Outcome Score-Physical Function Short Form, Patient-reported Outcomes Measurement Information System (PROMIS)-Physical Function Short Form 10a, PROMIS Global-Mental, or PROMIS Global-Physical questionnaires. Logistic regressions and statistical analyses were used to determine the effect of a MHD on MCID-I/MCID-W rates. RESULTS: Data included 4,562 patients (4,190 primary TJAs/372 rTJAs). In primary total hip arthroplasty (pTHA), MHD-affected outcomes for Hip Disability and Osteoarthritis Outcome Score-Physical Function Short Form (MCID-I: 81% versus 86%, P = 0.007; MCID-W: 6.0% versus 3.2%, P = 0.008), Physical Function Short Form 10a (MCID-I: 68% versus 77%, P < 0.001), PROMIS Global-Mental (MCID-I: 38% versus 44%, P = 0.009), and PROMIS Global-Physical (MCID-I: 61% versus 73%, P < 0.001; MCID-W: 14% versus 7.9%, P < 0.001) versus pTHA patients without MHD. A MHD led to lower rates of MCID-I for PROMIS Global-Physical (MCID-I: 56% versus 63%, P = 0.003) in primary total knee arthroplasty patients. No effects from a MHD were observed in rTJA patients. DISCUSSION: The presence of a MHD had a prominent negative influence on pTHA patients. Patients who underwent rTJA had lower MCID-I rates, higher MCID-W rates, and lower patient-reported outcome measure scores despite less influence from a MHD. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

[ 11 C]-PBR28 positron emission tomography signal as an imaging marker of joint inflammation in knee osteoarthritis.

ABSTRACT: Although inflammation is known to play a role in knee osteoarthritis (KOA), inflammation-specific imaging is not routinely performed. In this article, we evaluate the role of joint inflammation, measured using [ 11 C]-PBR28, a radioligand for the inflammatory marker 18-kDa translocator protein (TSPO), in KOA. Twenty-one KOA patients and 11 healthy controls (HC) underwent positron emission tomography/magnetic resonance imaging (PET/MRI) knee imaging with the TSPO ligand [ 11 C]-PBR28. Standardized uptake values were extracted from regions-of-interest (ROIs) semiautomatically segmented from MRI data, and compared across groups (HC, KOA) and subgroups (unilateral/bilateral KOA symptoms), across knees (most vs least painful), and against clinical variables (eg, pain and Kellgren-Lawrence [KL] grades). Overall, KOA patients demonstrated elevated [ 11 C]-PBR28 binding across all knee ROIs, compared with HC (all P 's < 0.005). Specifically, PET signal was significantly elevated in both knees in patients with bilateral KOA symptoms (both P 's < 0.01), and in the symptomatic knee ( P < 0.05), but not the asymptomatic knee ( P = 0.95) of patients with unilateral KOA symptoms. Positron emission tomography signal was higher in the most vs least painful knee ( P < 0.001), and the difference in pain ratings across knees was proportional to the difference in PET signal ( r = 0.74, P < 0.001). Kellgren-Lawrence grades neither correlated with PET signal (left knee r = 0.32, P = 0.19; right knee r = 0.18, P = 0.45) nor pain ( r = 0.39, P = 0.07). The current results support further exploration of [ 11 C]-PBR28 PET signal as an imaging marker candidate for KOA and a link between joint inflammation and osteoarthritis-related pain severity.

Patients Consistently Report Worse Outcomes Following Revision Total Knee Arthroplasty Compared to Primary Total Knee Arthroplasty.

BACKGROUND: Differences in patient-reported outcome measures (PROMs) between primary TKA (pTKA) and revision TKA (rTKA) have not been well-studied. Therefore, we compared pTKA and rTKA patients by the rates of achieving the Minimal Clinically Important Difference for Improvement (MCID-I) and Worsening (MCID-W). METHODS: A total of 2,448 patients (2,239 pTKAs/209 rTKAs) were retrospectively studied. Patients who completed the Knee Injury and Osteoarthritis Outcome Score-Physical Function Short Form (KOOS-PS), Patient-Reported Outcomes Measurement Information System (PROMIS) Physical Function Short Form 10a (PF10a), PROMIS Global-Mental, or PROMIS Global-Physical questionnaires were identified by Current Procedural Terminology (CPT) codes. Patient-reported outcome measures and MCID-I/MCID-W rates were compared. Multivariate logistic regression models measured relationships between surgery type and postoperative outcomes. RESULTS: Patients who underwent rTKA (all causes) had lower rates of improvement and higher rates of worsening compared to pTKA patients for KOOS-PS (MCID-I: 54 versus 68%, P < .001; MCID-W: 18 versus 8.6%, P < .001), PF10a (MCID-I: 44 versus 65%, P < .001; MCID-W: 22 versus 11%, P < .001), PROMIS Global-Mental (MCID-I: 34 versus 45%, P = .005), and PROMIS Global-Physical (MCID-I: 51 versus 60%, P = .014; MCID-W: 29 versus 14%, P < .001). Undergoing revision was predictive of worsening postoperatively for KOOS-PS, PF10a, and PROMIS Global-Physical compared to pTKA. Postoperative scores were significantly higher for all 4 PROMs following pTKA. CONCLUSION: Patients reported significantly less improvement and higher rates of worsening following rTKA, particularly for PROMs that assessed physical function. Although pTKA patients did better overall, the improvement rates may be considered relatively low and should prompt discussions on improving outcomes following pTKA and rTKA. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

One-Year Postoperative Patient-Reported Outcome Measures Are Associated With Three-Year to Five-Year Postoperative Satisfaction in Total Knee Arthroplasty.

BACKGROUND: Over the past couple of decades, the definition of success after total knee arthroplasty (TKA) has shifted away from clinician-rated metrics and toward the patient's subjective experience. Therefore, understanding the aspects of patient recovery that drive 3-year to 5-year satisfaction after TKA is crucial. The aims of this study were to (1) determine the 1-year postoperative factors, specifically patient-reported outcome measures (PROMs) that were associated with 3-year and 5-year postoperative satisfaction and (2) understand the factors that drive those who are not satisfied at 1 year postoperatively to become satisfied later in the postoperative course. METHODS: This was a retrospective study of 402 TKA patients who were gathered prospectively and presented for their 1-year follow-up. Demographics were collected preoperatively and patient-reported outcomes were collected at 1, 3, and 5 years postoperatively. Logistic regressions were used to identify the factors at 1 year that were associated with 3-year and 5-year satisfaction. RESULTS: Associations between 1-year PROMs with 3-year satisfaction were observed. Longer term satisfaction at 5 years was more closely associated with EuroQol 5 Dimension Mobility, Activity Score, and Numerical Rating Scale Satisfaction. Of those who were not satisfied at 1 year, EuroQol 5 Dimension Mobility, Knee Disability Osteoarthritis Outcome Score Function in Sport and Recreation, and Satisfaction were associated with becoming satisfied at 3 years. CONCLUSION: The 1-year PROMs were found to be associated with satisfaction at 3 to 5 years after TKA. Importantly, many of the PROMs that were associated with 3-year to 5-year satisfaction, especially in those who were not originally satisfied at 1 year, were focused on mobility and activity level.

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.

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.

Investigation of Characteristic Motion Patterns of the Knee Joint During a Weightbearing Flexion.

This study aimed to develop and validate a novel flexion axis concept by calculating the points on femoral condyles that could maintain constant heights during knee flexion. Twenty-two knees of 22 healthy subjects were investigated when performing a weightbearing single leg lunge. The knee positions were captured using a validated dual fluoroscopic image system. The points on sagittal planes of the femoral condyles that had minimal changes in heights from the tibial plane along the flexion path were calculated. It was found that the points do formulate a medial-lateral flexion axis that was defined as the iso-height axis (IHA). The six degrees of freedom (6DOF) kinematics data calculated using the IHA were compared with those calculated using the conventional transepicondylar axis and geometrical center axis. The IHA measured minimal changes in proximal-distal translations and varus-valgus rotations along the flexion path, indicating that the IHA may have interesting clinical implications. Therefore, identifying the IHA could provide an alternative physiological reference for improvement of contemporary knee surgeries, such as ligament reconstruction and knee replacement surgeries that are aimed to reproduce normal knee kinematics and medial/lateral soft tissue tensions during knee flexion.

Patient-Reported Outcomes Following Revision Total Hip Arthroplasty Demonstrate Less Improvement and Significantly Higher Rates of Worsening Compared to Primaries.

BACKGROUND: Patient-reported outcome measures (PROMs) provide the patient's perspective following total hip arthroplasty (THA), although differences between primary THA (pTHA) and revision THA (rTHA) remain unclear. Thus, we compared the Minimal Clinically Important Difference for Improvement (MCID-I) and Worsening (MCID-W) in pTHA and rTHA patients. METHODS: Data from 2,159 patients (1,995 pTHAs/164 rTHAs) who had completed Hip Disability and Osteoarthritis Outcome Score-Physical Function Short Form (HOOS-PS), Patient-Reported Outcomes Measurement Information System (PROMIS) Physical Function Short Form 10a (PF10a), PROMIS Global-Mental, or PROMIS Global-Physical questionnaires were analyzed. The PROMs and MCID-I/MCID-W rates were compared using statistical tests and multivariate logistic regressions. RESULTS: Compared to the pTHA group, the rTHA group had lower rates of improvement and higher rates of worsening for almost all PROMs, including HOOS-PS (MCID-I: 54 versus 84%, P < .001; MCID-W: 24 versus 4.4%, P < .001), PF10a (MCID-I: 44 versus 73%, P < .001; MCID-W: 22 versus 5.9%, P < .001), PROMIS Global-Mental (MCID-W: 42 versus 28%, P < .001), and PROMIS Global-Physical (MCID-I: 41 versus 68%, P < .001; MCID-W: 26 versus 11%, P < .001). Odds ratios supported rates of worsening following revision for the HOOS-PS (Odds Ratio (OR): 8.25, 95% Confidence Interval (CI): 5.62 to 12.4, P < .001), PF10a (OR: 8.34, 95% CI: 5.63 to 12.6, P < .001), PROMIS Global-Mental (OR: 2.16, 95% CI: 1.41 to 3.34, P < .001), and PROMIS Global-Physical (OR: 3.69, 95% CI: 2.46 to 5.62, P < .001). CONCLUSION: Patients reported higher rates of worsening and lower rates of improvement following rTHA than pTHA, with significantly less score improvement and lower postoperative scores for all PROMs after revision. Most patients reported improvements following pTHA, with few worsening postoperatively. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Intersurgeon Variability of Minimal Clinically Important Difference for Worsening Achievement Rates After Total Joint Arthroplasty.

BACKGROUND: Using the Patient-Reported Outcome Measurement Information System, we sought to evaluate surgeon performance variability via minimal clinically important difference for worsening (MCID-W) achievement rates in primary and revision total knee and hip arthroplasty. METHODS: This retrospective study analyzed 3,496 primary total hip arthroplasty (THA), 4,622 primary total knee arthroplasty (TKA), 592 revision THA, and 569 revision TKA patients. Patient factors collected included demographics, comorbidities, and Patient-Reported Outcome Measurement Information System physical function short form 10a scores. Surgeon factors collected included caseload, years of experience, and fellowship training. The MCID-W rate was calculated as the percent of patients in each surgeon's cohort who achieved MCID-W. Distribution was presented via a histogram with associated average, standard deviation, range, and interquartile range (IQR). Linear regressions were performed to evaluate the potential correlation between surgeon- and patient-level factors with MCID-W rate. RESULTS: The average MCID-W rates of the surgeons represented in the primary THA and TKA cohorts were 12.7 ± 9.2% (range, 0 to 35.3%; IQR, 6.7 to 15.5%) and 18.0 ± 8.2% (range, 0 to 36%; IQR, 14.3 to 22.0%). The average MCID-W rates among the revision THA and TKA surgeons were 36.0 ± 22.2% (range, 9.1 to 90%; IQR, 25.0 to 41.4%) and 21.2 ± 7.7% (range, 8.1 to 37.0%; IQR, 16.6 to 25.4%). Strong correlations were not found between patient- or surgeon-level factors and MCID-W rate of the surgeon. CONCLUSION: We demonstrated variance in MCID-W achievement rates across surgeons in both primary and revision joint arthroplasty, independent of patient- or surgeon-level factors.

The Dome Technique for Managing Massive Anterosuperior Medial Acetabular Bone Loss in Revision Total Hip Arthroplasty: Short-Term Outcomes.

Purpose: The dome technique is a technique used in performance of revision total hip arthroplasty (THA) involving intraoperative joining of two porous metal acetabular augments to fill a massive anterosuperior medial acetabular bone defect. While excellent outcomes were achieved using this surgical technique in a series of three cases, short-term results have not been reported. We hypothesized that excellent short-term clinical and patient reported outcomes could be achieved with use of the dome technique. Materials and Methods: A multicenter case series was conducted for evaluation of patients who underwent revision THA using the dome technique for management of Paprosky 3B anterosuperior medial acetabular bone loss from 2013-2019 with a minimum clinical follow-up period of two years. Twelve cases in 12 patients were identified. Baseline demographics, intraoperative variables, surgical outcomes, and patient reported outcomes were acquired. Results: The implant survivorship was 91% with component failure requiring re-revision in only one patient at a mean follow-up period of 36.2 months (range, 24-72 months). Three patients (25.0%) experienced complications, including re-revision for component failure, inter-prosthetic dual-mobility dissociation, and periprosthetic joint infection. Of seven patients who completed the HOOS, JR (hip disability and osteoarthritis outcome score, joint replacement) survey, five patients showed improvement. Conclusion: Excellent outcomes can be achieved using the dome technique for management of massive anterosuperior medial acetabular defects in revision THA with survivorship of 91% at a mean follow-up period of three years. Conduct of future studies will be required in order to evaluate mid- to long-term outcomes for this technique.

Minimum 7-Year Follow-Up of Vitamin E-Diffused and Highly Cross-Linked Polyethylene Liners in Total Hip Arthroplasty: Findings From a Prospective, International, Multicenter Study of 977 Patients.

BACKGROUND: Vitamin E-diffused highly cross-linked polyethylene (VEPE) acetabular liners for total hip arthroplasty (THA) have shown favorable results in small cohort studies. However, larger studies are warranted to compare its performance to highly cross-linked polyethylene (XLPE) and demonstrate clinical significance in 10-year arthroplasty outcomes. This study compared acetabular liner wear and patient-reported outcome measures (PROMs) between patients treated with VEPE and XLPE liners in a prospective, international, multicenter study with minimum 7-year follow-up. METHODS: A total of 977 patients (17 centers; 8 countries) were enrolled from 2007 to 2012. The centers were randomly assigned to implants. At 1-year, 3-year, 5-year, and 7-year postoperative visits, radiographs, PROMs, and incidence of revision were collected. Acetabular liner wear was calculated using computer-assisted vector analysis of serial radiographs. General health, disease progression, and treatment satisfaction reported by patients were scored using 5 validated surveys and compared using Mann-Whitney U tests. At 7 years, 75.4% of eligible patients submitted data. RESULTS: The mean acetabular liner wear rate was -0.009 mm/y and 0.024 mm/y for the VEPE and XLPE group, respectively (P = .01). There were no statistically significant differences in PROMs. The overall revision incidence was 1.8% (n = 18). The revision incidence in VEPE and XLPE cohorts were 1.92% (n = 10) versus 1.75% (n = 8), respectively. CONCLUSION: We found that VEPE acetabular liners in total hip arthroplasty led to no significant clinical difference in 7-year outcomes as measured by acetabular liner wear rate, PROMs, and revision rate. While VEPE liners showed less wear, the wear rate for both the VEPE and XLPE liners was below the threshold for osteolysis. Therefore, the difference in liner wear may indicate comparative clinical performance at 7 years, as further indicated by the lack of difference in PROMs and the low revision incidence.

Postoperative Outcomes in Total Hip and Total Knee Arthroplasty for Patients Who Have Multiple Myeloma.

BACKGROUND: Advancements in oncologic care have increased the longevity of patients who have multiple myeloma, although outcomes beyond the early postoperative period following total hip arthroplasty (THA) and total knee arthroplasty (TKA) remain unknown. This study investigated the influence of preoperative factors on implant survivorship following THA and TKA after a minimum 1-year interval for multiple myeloma patients. METHODS: Using our institutional database, we identified 104 patients (78 THAs, 26 TKAs) from 2000 to 2021 diagnosed with multiple myeloma before their index arthroplasty by International Classification of Diseases, Ninth and Tenth Revisions (ICD-9 and ICD-10) codes 203.0× and C90.0× and corresponding Current Procedural Terminology (CPT) codes. Demographic data, oncologic treatments, and operative variables were collected. Multivariate logistic regressions assessed variables of interest, and Kaplan-Meier curves were used to estimate implant survival. RESULTS: There were 9 (11.5%) patients who underwent revision THA after an average time of 1,312 days (range, 14 to 5,763), with infection (33.3%), periprosthetic fracture (22.2%), and instability (22.2%) being the most common indications. Of these patients, 3 (33.3%) underwent multiple revision surgeries. There was 1 (3.8%) patient who underwent revision TKA at 74 days postoperatively for infection. Patients treated with radiotherapy were more likely to require revision THA (odds Rratio (OR): 6.551, 95% confidence interval (CI): 1.148-53.365, P = .045), but no predictors of failure were identified for TKA patients. CONCLUSION: Orthopaedic surgeons should know that multiple myeloma patients have a relatively high risk of revision, particularly following THA. Accordingly, patients who have risk factors for failure should be identified preoperatively to avoid poor outcomes. 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.

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.

Sarcopenia is an independent risk factor for failure to achieve the 1-year MCID of the KOOS, JR and PROMIS PF-SF10a after TKA.

BACKGROUND: Sarcopenia, which is a progressive and multifactorial condition of decreased muscle strength, has been identified as an independent predictor for falls, revision, infection, and readmissions following total knee arthroplasty (TKA), but its association to patient reported outcomes (PROMs) is less studied. The aim of this study is to determine if sarcopenia and other measures of body composition are correlated with ability to achieve the 1-year minimal clinically important difference (MCID) of the KOOS JR and PROMIS-PF-SF10a following primary TKA. METHODS: A multicenter retrospective case-control study was performed. Inclusion criteria consisted of patients over the age of 18 undergoing primary TKA, body composition metrics determined by computed tomography (CT), and available pre- and post-operative PROM scores. Predictors of achievement of the 1-year MCID of the KOOS JR and PROMIS PF-SF-10a were determined through a multivariate linear regression. RESULTS: 140 primary TKAs met inclusion criteria. 74 (52.85%) patients achieved the 1-year KOOS, JR MCID and 108 (77.41%) patients achieved the 1-year MCID for the PROMIS PF-SF10a. Sarcopenia was independently associated with decreased odds of achieving the MCID of both the KOOS, JR (OR 0.31, 95%CI 0.10-0.97, p = 0.04) and the PROMIS-PF-SF10a (OR 0.32, 95%CI 0.12-0.85, p = 0.02) CONCLUSIONS: In our study, sarcopenia was independently associated with increased odds of failure to achieve the 1-year MCID of the KOOS, JR and PROMIS PF-SF10a after TKA. Early identification of sarcopenic patients may be beneficial for arthroplasty surgeons so that targeted nutritional counseling and exercises can be recommended prior to TKA.

A Matched Comparison of the Rates of Achieving the Minimal Clinically Important Difference Following Conversion and Primary Total Hip Arthroplasty.

BACKGROUND: Patient-reported outcome measures (PROMs) are often lower following conversion total hip arthroplasty (cTHA) compared to matched primary total hip arthroplasty (THA) controls. However, the minimal clinically important differences (MCIDs) for any PROMs are yet to be analyzed for cTHA. This study aimed to (1) determine if patients undergoing cTHA achieve primary THA-specific 1-year PROM MCIDs at comparable rates to matched controls undergoing primary THA and (2) establish 1-year MCID values for specific PROMs following cTHA. METHODS: A retrospective case-control study was conducted using 148 cases of cTHA which were matched 1:2 to 296 primary THA patients. Previously defined anchor values for 2 PROM measures in primary THA were used to compare cTHA to primary THA, while novel cTHA-specific MCID values for 2 PROMs were calculated through a distribution method. Predictors of achieving the MCID of PROMs were analyzed through multivariate logistic regressions. RESULTS: Conversion THA was associated with decreased odds of achieving the primary THA-specific 1-year Hip dysfunction and Osteoarthritis Outcome Score for Joint Replacement PROM (Odds Ratio: 0.319, 95% Confidence Interval: 0.182-0.560, P < .001) and Patient Reported Outcomes Measurement Information System Physical Function Short-Form-10a PROM (Odds Ratio: 0.531, 95% Confidence Interval: 0.313-0.900, P = .019) MCIDs in reference to matched primary THA patients. Less than 60% of cTHA patients achieved an MCID. The 1-year MCID of the Hip dysfunction and Osteoarthritis Outcome Score for Joint Replacement and Patient Reported Outcomes Measurement Information System Physical Function Short-Form-10a specific to cTHA were +10.71 and +4.68, respectively. CONCLUSION: While cTHA is within the same diagnosis-related group as primary THA, patients undergoing cTHA have decreased odds of achieving 1-year MCIDs of primary THA-specific PROMs. LEVEL OF EVIDENCE: Level III, retrospective comparative study.