Minimum 10-Year Follow-Up of Vitamin-E Diffused Highly Crosslinked Polyethylene Liners in Total Hip Arthroplasty: Comparative Evaluation from a Prospective, International, Multicenter Cohort Study.

BACKGROUND: Total hip arthroplasty (THA) is a proven, effective treatment for end-stage osteoarthritis. The success of THA is due in part to highly crosslinked (XL) polyethylene implants. In 2007, a new generation of polyethylene liners entered clinical use. The new liners infused polyethylene with vitamin E (EP). The EP liner was hypothesized to prevent the loss of mechanical properties caused by oxidation, extending the lifetime of the implant. This international prospective study aimed to quantify the clinical outcomes of a 977-patient cohort receiving EP and XL liners 10 years after surgery. METHODS: The prospective cohort study began in 2007, including eight countries and seventeen centers. The final cohort included 977 patients (EP liner: n = 520; XL liner: n = 457). Patients were followed preoperatively, postoperatively, and at 1, 3, 5, 7, and 10 years. Each follow-up visit involved clinical evaluation, radiography, and survey collection. Demographics and revisions were also recorded. Mann-Whitney U tests were used to evaluate statistical differences. RESULTS: At ten years following surgery, 534 patients were eligible for follow-up. Of those eligible, 352 patients returned for clinical evaluation (65.9% eligible; 36.0% overall). No statistical differences were found (P > 0.05) in the demographics of the followed-up cohort. The linear wear rates were 0.00338 mm/year for XL liners and 0.0236 mm/year for EP liners using individual regression (P < 0.0001). No significant difference was observed in wear rates using cohort regression. Similarly, surveys suggested no significant outcomes between the EP and XL liner cohorts. The overall incidence of revision was 2.3% for EP and 2.0% for XL liners. CONCLUSION: The EP liner demonstrated significantly lower wear than its XL counterparts at 10-years after implantation. Results are promising, as vitamin E polyethylene may improve the lifetime performance of THA implants and ensure arthroplasty innovations reflect the changing patient population.

Patient-reported outcomes in total hip arthroplasty for patients with anatomically contoured femoral heads.

INTRODUCTION: Iliopsoas tendinitis after total hip arthroplasty (THA) has become more prevalent with the increased use of large-diameter femoral heads impinging on native surrounding tissues. Anatomically contoured heads (ACH) are soft-tissue-friendly femoral heads created to minimise this issue. This retrospective study assesses iliopsoas tendinitis prevalence and re-operations in primary THAs with ACH, while determining the minimal clinically important difference (MCID) achievement and improvement with 5 patient-reported outcome measures (PROMs). METHODS: We conducted a retrospective analysis of 53 ACHs from January 2020 to July 2023. Patients who completed Hip Injury and Osteoarthritis Outcome Score-Physical Function Short Form (HOOS-PS), Patient-Reported Outcomes Measurement Information System (PROMIS) Physical Function Short Form 10a (PF SF-10a), PROMIS Global Health (GH)-Mental, or PROMIS GH-Physical, and pain score questionnaires were identified. PROM scores were collected preoperatively and at 3-month and 1-year postoperative intervals. Comparisons using chi-square and ANOVA tests were applied. RESULTS: The rates of achieving MCID and improvement within the first year were (69.2 vs. 76.9%) for PROMIS GH-Physical, (38.5 vs. 46.2%) for PROMIS GH-Mental, (71.4 vs. 92.9%) for HOOS-PS, (80.0 vs. 80.0%) for PROMIS PF SF-10a, and (74.0 vs. 91.7%) for pain scores. PROM scores at 3 months and 1 year significantly varied across all categories, except for PROMIS GH-Mental. No patients had iliopsoas tendinitis, dislocations, or re-operations. DISCUSSION: ACH implants may alleviate anterior hip pain, while maintaining comparable strength and bio-compatibility to conventional femoral heads. This study underscores the early safety and potential of ACH implants in reducing iliopsoas tendinitis and impingement.

Revision Total Knee Arthroplasty Achieves Minimal Clinically Important Difference Faster than Primary Total Knee Arthroplasty.

INTRODUCTION: Revision total knee arthroplasty (rTKA) remains underexplored regarding patient-reported outcome measures (PROMs), particularly in terms of time to reach Minimal Clinically Important Difference (MCID). This study addresses this gap by comparing the time to achieve MCID between primary TKA (pTKA) and rTKA patients, providing valuable insights into their recovery trajectories. METHODS: A total of 8,266 TKAs (7,618 pTKA and 648 rTKA) were retrospectively studied in a multi-institutional arthroplasty registry. Patients who completed the Patient-Reported Outcomes Measurement Information System (PROMIS) Global Physical, PROMIS Physical Function Short Form 10a (PF-10a), and Knee Injury and Osteoarthritis Outcome Score-Physical Function Short Form (KOOS-PS) questionnaires were identified by Current Procedural Terminology (CPT) codes. Survival curves with and without interval-censoring were utilized to evaluate the time to achieve MCID. RESULTS: Comparing the time to achieve MCID, rTKAs were significantly faster than pTKA for PROMIS Global Physical (3.5 versus 3.7 months, P = 0.004) and KOOS-PS (3.3 versus 4.2 months, P < 0.001), but similar for PROMIS PF-10a (4.4 versus 4.8 months, P = 0.057). Interval-censoring also showed similar trends with earlier times to achieve MCID for rTKAs for PROMIS Global Physical (0.6 to 0.61 versus 0.97 to 0.97 months, P = 0.009) and KOOS-PS (0.97 to 0.97 versus 1.47 to 1.47 months, P < 0.001), but not for PROMIS PF-10a (2.43 to 2.54 versus 1.90 to 1.91 months, P = 0.92). CONCLUSION: The present study revealed that the time to achieve MCID was faster in patients undergoing rTKA compared to those undergoing pTKA. These findings allow surgeons to reassure preoperative revision TKA patients that their recovery to a minimal clinically important difference postoperatively may be quicker than expected, especially when compared to their initial recovery after primary TKA.

Comparing Rates of Minimal Clinically Important Difference Between Manual and Robotic-Assisted Total Knee Arthroplasty.

BACKGROUND: Differences in patient-reported outcome measures (PROMs) between manual total knee arthroplasty (mTKA) and robotic-assisted TKA (rTKA) have not been adequately assessed. We compared the minimal clinically important difference for improvement (MCID-I) and Worsening (MCID-W) between mTKA and rTKA patients. METHODS: Patients who underwent primary TKA (874 mTKA, 439 rTKA) with complete pre-operative and one-year post-operative PROMs were retrospectively identified using a multi-hospital joint arthroplasty registry. Patient-Reported Outcomes Measurement Information System Physical Function Short Form 10a (PROMIS PF-10a), PROMIS Global - Physical, or Knee Injury and Osteoarthritis Outcome Score-Physical Function Short Form (KOOS-PS) were collected. The MCID-I, MCID-W, and "no significant change" rates were calculated using distribution-based methods. Propensity-score matching was performed to control for confounding. RESULTS: Similar 90-day pulmonary embolism (P = 0.26), deep venous thrombosis (P = 0.67), and emergency department visit (P = 0.35) rates were found. The 90-day readmission rate for mTKA was 1.7 and 3.4% for rTKA (P = 0.08), and overall revision rates were 2.2% for mTKA and 0.7% for rTKA (P = 0.07). Revision-free survival was 99% at one and two years for both groups (P = 0.65 and P = 0.43, respectively). There were no differences in the proportion of patients achieving MCID-I or MCID-W for PROMIS PF-10a, PROMIS Global - Physical, or KOOS-PS. The MCID-I for PROMIS PF-10a was achieved in 65.5 and 62.2% of patients who had mTKA and rTKA, respectively (P = 0.32). CONCLUSION: Our study demonstrated similar complication rates, and MCID-I and MCID-W attainment rates between mTKA and rTKA patients. Future studies should assess MCID attainment rates in the long term and in larger cohorts, comparing mTKA and rTKA.

Diffusion doping of analgesics into UHMWPE for prophylactic pain management.

Pain management after total joint arthroplasty is often addressed by systemic delivery of opioids. Local delivery of non-opioid analgesic drugs directly in the joint space from the UHMWPE component of the prosthesis would be highly beneficial to increase the efficacy of the drugs, decreasing the overall side effects and the risk of opioid addiction. It has been shown that effective concentrations of local analgesics can be achieved by eluting from analgesic-blended UHMWPE; however, this approach is limited by the decrease in mechanical properties resulting from the extent of phase separation of the blended drugs from the polymeric matrix. Here we hypothesized that mechanical properties could be maintained by incorporating analgesics into solid form UHMWPE by diffusion as an alternative method. Lidocaine or bupivacaine were diffused in solid form UHMWPE with or without radiation crosslinking. The loaded drug content, the spatial distribution of the drugs and their chemical stability after doping were characterized by FTIR and NMR spectroscopy, respectively. Drug release kinetics, tensile mechanical properties and wear rates were assessed. The results showed that diffusion doping could be used as a promising method to obtain a therapeutic implant material without compromising its mechanical and structural integrity.

MCID achievement in staged bilateral total knee arthroplasty: Are both joints created equal?

BACKGROUND: A notable portion of unilateral total knee arthroplasty (TKA) patients undergo arthroplasty of the contralateral knee. The aims of this study were to describe the Minimal Clinically Important Difference for Improvement (MCID-I) and Worsening (MCID-W) in staged bilateral TKAs (BTKAs) and identify factors associated with these outcomes. METHODS: Patients with staged BTKA were retrospectively reviewed. Demographics, surgery details, and Patient-Reported Outcome Measurement Information System Physical Function Short Form 10a (PROMIS PF10a) were collected. MCID-I and MCID-W were defined for PROMIS PF10a. Patients were stratified into nine groups based on the MCID achievement of the first and second TKA: (A) MCID-I, MCID- I, (B) MCID-I, Neutral, (C) MCID-I, MCID-W, (D) Neutral, MCID-I, (E) Neutral, Neutral, (F) Neutral, MCID-W, (G) MCID- W, MCID-I, (H) MCID-W, Neutral, (I) MCID-W, MCID-W. Neutral patients did not achieve either MCID-I or MCID-W. RESULTS: The final cohort consisted of 59 staged BTKA patients. In patients who achieved MCID-I in the first TKA, 39.1% achieved MCID-I again in the second TKA (A), 39.1% were neutral (B), and 21.7% achieved MCID-W (C) in the second TKA. However, 77.8% of those who achieved MCID-W in the first joint (n = 9) went on to achieve MCID-I (G) in the second TKA. Those who achieved MCID-I after both TKAs (A) had a longer staged interval than those who achieved first MCID-I, then MCID-W (C) (15 months vs 8 months, P = 0.0113). CONCLUSION: In staged BTKA, MCID achievement of the first TKA may not be associated with the outcome of the second TKA.

The Role of Risk Tolerance in a Patient's Decision to Undergo Total Knee and Hip Arthroplasty.

BACKGROUND: A patient's decision-making process to undergo surgery is crucial for surgeons to understand for patient-counseling purposes. Total knee and hip arthroplasty, like any other major surgery, is associated with serious, sometimes life-threatening, complications. Using the results of discrete choice experiments (DCEs), we aimed to understand the relationship between a patient's risk tolerance and choosing to undergo surgery in real life. METHODS: This is a retrospective study of prospectively collected DCE results for 142 potential knee or hip arthroplasty clinic patients from October 2021 to March 2022. The DCE presented the patient with 2 scenarios, each of which was made up of different combinations of attributes and levels. A hierarchal Bayesian model was used to obtain a risk score that reflected the risk attributes chosen by each patient. Logistic regressions were then used to evaluate the association between a patient's willingness to incur risk and their decision to undergo a total joint arthroplasty. RESULTS: Of the 142 patients enrolled in the DCE, 89 (62.3%) underwent a total joint arthroplasty. Risk score (odds ratio [OR] = 2.6, 95% confidence interval [CI] 1.1 to 6.6, P = 0.04), men (OR = 2.5, 95% CI 1.1 to 5.9, P = 0.028), and patients who have hip osteoarthritis (OR = 2.4, 95% CI 1.1 to 5.5, P = 0.036) increased the odds of undergoing arthroplasty, whereas physical function of at least 75% at the initial visit (OR = 0.3, 95% CI 0.1 to 0.7, P = 0.004) decreased these odds. CONCLUSIONS: We found that a patient's willingness to incur risk, lower baseline physical function, and men were all independently associated with undergoing total knee arthroplasty. We believe that these findings prompt much-needed future studies that focus solely on the relationship between patients' inherent risk behavior and surgical and patient-reported outcomes.

Comparison of Time and Rate of Achieving Minimal Clinically Important Difference: Robotic Versus Manual Unicompartmental Knee Arthroplasty.

BACKGROUND: Robotics in unicompartmental knee arthroplasty (UKA) continues to increase with the ever-growing demand to use technology in the surgical setting. However, no studies have used minimal clinically important difference (MCID) to compare patient-reported outcome measures (PROMs) between robotic UKA (rUKA) and manual UKA (mUKA). This study aimed to compare the rate of achieving MCID for improvement (MCID-I) and worsening (MCID-W) and the time to achieving MCID. METHODS: We conducted a retrospective analysis of robotic and manual UKAs performed between 2016 and 2022. Preoperative and postoperative Patient-Reported Outcomes Measurement Information System (PROMIS) Global Physical, PROMIS Physical Function Short-Form 10a (PF-10a), and Knee Injury and Osteoarthritis Outcome Score-Physical Function Short-Form (KOOS-PS) scores were collected. Patients were stratified on reaching MCID-I, MCID-W, or "no notable change" (score between MCID-W and MCID-I). Survival curves with and without interval censoring were used to assess the time to achieving the MCID. Log-rank and weighted log-rank tests were used to compare groups. RESULTS: A total of 256 UKAs (64 robotic and 192 manual) were analyzed. No differences were observed in the proportion of patients achieving MCID-I or MCID-W across all three PROMs. Similarly, median time to achieving MCID showed no significant differences between rUKA and mUKA for PROMIS Global Physical (3.3 versus 4.9 months, P = 0.44), PROMIS PF-10a (7.7 versus 8.3 months, P = 0.93), and KOOS-PS (3.0 versus 6.0 months, P = 0.055) scores, both with and without interval censoring. DISCUSSION: This study indicates that rUKA and mUKA exhibit comparable rates of achieving MCID-I and MCID-W, along with similar median time to reach MCID. These findings offer valuable patient-centric insights into the effectiveness of rUKA. Additional studies evaluating the long-term outcomes of rUKA are needed to determine its long-term advantages. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Weighing the Impact: The Influence of Body Mass Index on Facility Costs in Total Joint Arthroplasty.

BACKGROUND: Using time-driven activity-based costing (TDABC), a novel cost calculation method that more accurately reflects true resource utilization in health care, we sought to compare the total facility costs across different body mass index (BMI) groups following total joint arthroplasty (TJA). METHODS: The study consisted of 13,806 TJAs (7,340 total knee arthroplasties [TKAs] and 6,466 total hip arthroplasties [THAs]) performed between 2019 and 2023. The TDABC data from an analytics platform was employed to depict total facility costs, comprising personnel and supply costs. For the analysis, patients were stratified into four BMI categories: <30, 30 to <35, 35 to <40, and ≥40. Multivariable regression was used to determine the independent effect of BMI on facility costs. RESULTS: When indexed to patients who had BMI <30, elevated BMI categories (30 to <35, 35 to <40, and ≥40) were associated with higher total personnel costs (TKA 1.03x versus 1.07x versus 1.13x, P < .001; THA 1.00x versus 1.08x versus 1.08x, P < .001), and total supply costs (TKA 1.01x versus 1.04x versus 1.04x, P < .001; THA 1.01x versus 1.02x versus 1.03x, P = .007). Total facility costs in TJAs were significantly greater in higher BMI categories (TKA 1.02x versus 1.05x versus 1.08x, P < .001; THA 1.01x versus 1.05x versus 1.05x, P < .001). Notably, when incorporating adjustments for demographics and comorbidities, BMI values of 35, 40, and 45 relative to BMI of 25, exhibit a significant association with a 2, 3, and 5% increase in total facility cost for TKAs and a 3, 5, and 7% increase for THAs. CONCLUSIONS: Using TDABC methodology, this study found that overall facility costs of TJAs increase with BMI. The present study provides patient-level cost insights, indicating the potential need for reassessment of physician compensation models in this population. Further studies may facilitate the development of risk-adjusted procedural codes and compensation models for public and private payors. LEVEL OF EVIDENCE: Level IV, economic and decision analyses.

Tibiofemoral articulation and axial tibial rotation of the knee after a cruciate retaining total knee arthroplasty.

PURPOSE: Numerous research has reported that total knee arthroplasty (TKA) cannot reproduce axial tibial rotations of normal knees. The objective of this study was to measure the tibiofemoral articular contact motions and axial tibial rotations of TKA knees to investigate the mechanism causing the knee kinematics change of after TKAs. METHODS: Eleven patients with unilateral cruciate retaining (CR) TKA were tested for measurements of knee motion during a weight-bearing flexion from 0° to 105° using an imaging technique. The tibiofemoral contact kinematics were determined using the contact points on medial and lateral surfaces of the tibia and femoral condyles. Axial tibial rotations were calculated using the differences between the medial and lateral articulation distances on the femoral condyles and tibial surfaces at each flexion interval of 15°. RESULTS: On femoral condyles, articular contact distances are consistently longer on the medial than on the lateral sides (p < 0.05) up to 60° of flexion, corresponding to internal tibial rotations (e.g., 1.3° ± 1.0° at 15-30° interval). On tibial surfaces, the articular contact point on the medial side moved more posteriorly than on the lateral side at low flexion angles, corresponding to external tibial rotations (e.g., -1.4° ± 1.8° at 15-30° interval); and more anteriorly than on the lateral sides at mid-range flexion, corresponding to internal tibial rotations (e.g., 0.8° ± 1.7° at 45-60° interval). At higher flexion, articular motions on both femoral condyles and tibial surfaces caused minimal changes in tibial rotations. CONCLUSIONS: These results indicate that the axial tibial rotations of these TKA knees were mainly attributed to asymmetric articulations on the medial and lateral femoral condyles and tibial surfaces. The data can help understand the mechanisms causing axial tibial rotations of TKA knees and help improve implant designs for restoration of normal knee kinematics.

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.

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.

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.

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.

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.

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.

[ 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.