Examining racial disparities in utilization rate and perioperative outcomes following knee and hip arthroplasty.

BACKGROUND: Previous arthroplasty utilization research predominantly examined Black and White populations within the US. This is the first known study to examine utilization and complications in poorly studied minority racial groups such as Asians and Native Hawaiian/Pacific-Islanders (NHPI) as compared to Whites. RESULTS: Data from 3304 primary total hip and knee arthroplasty patients (2011 to 2019) were retrospectively collected, involving 1789 Asians (52.2%), 1164 Whites (34%) and 320 Native Hawaiians/Pacific Islanders (NHPI) (9.3%). The 2012 arthroplasty utilization rates for Asian, White, and NHPI increased by 32.5%, 11.2%, and 86.5%, respectively, by 2019. Compared to Asians, Whites more often underwent hip arthroplasty compared to knee arthroplasty (odds ratio (OR) 1.755; p < 0.001). Compared to Asians, Whites and NHPI more often received total knee compared to unicompartmental knee arthroplasty (White: OR 1.499; NHPI: OR 2.013; p < 0.001). White patients had longer hospitalizations (2.66 days) compared to Asians (2.19 days) (p = 0.005) following bilateral procedures. Medicare was the most common insurance for Asians (66.2%) and Whites (54.2%) while private insurance was most common for NHPI (49.4%). Compared to Asians, economic status was higher for Whites (White OR 0.695; p < 0.001) but lower for NHPI (OR 1.456; p < 0.001). After controlling for bilateral procedures, NHPI had a lower risk of transfusion compared to Asians (OR 0.478; p < 0.001) and Whites had increased risk of wound or systemic complications compared to Asians (OR 2.086; p = 0.045). CONCLUSIONS: Despite NHPI demonstrating a significantly poorer health profile and lower socioeconomic status, contrary to previous literature involving minority racial groups, no significant overall differences in arthroplasty utilization rates or perioperative complications could be demonstrated amongst the racial groups examined.

The influence of mental health on early outcomes following total hip arthroplasty.

BACKGROUND: Poor mental health is difficult to recognize and as a result, its association with recovery from total joint arthroplasty is difficult to assess. The purpose of this study was to investigate the relationship between overall mental health scores and outcomes in the early postoperative period following unilateral total hip arthroplasty (THA). METHODS: This is a retrospective review of prospectively collected data involving 142 patients who underwent primary unilateral THA. Independent variables included patient demographics and preoperative Patient-Reported Outcomes Measurement Information System (PROMIS), Global Physical Health (GPH) and Global Mental Health (GMH) and Hip Disability and Osteoarthritis Outcome Score, Joint Replacement (HOOS JR) scores as well as diagnoses of depression or anxiety. Dependent variables included length of stay (LOS), disposition at discharge, narcotic consumption until discharge, 6-week postoperative GPH, GMH and HOOS JR scores and magnitude of change compared to preoperative scores. Preoperative GMH and postoperative outcomes were compared using Pearson correlation coefficient, independent t-tests, Pearson's Chi-Square test, and univariate logistic regression. RESULTS: Patients with preoperative GMH scores below the 25% quartile were less likely to be discharged home and resulted in lower GPH, GMH and HOOS JR scores at 6-week follow-up compared to patients with preoperative GMH scores in the top 25% quartile. However, patients with low preoperative GMH scores demonstrated a greater magnitude of improvement in both the GPH and GMH scores compared to patients in the top 25% quartile. There was no difference in opioid consumption or LOS between either groups. When comparing patients with and without depression/anxiety, no difference was seen in any of the outcomes measured. CONCLUSION: Unilateral THA offers significant improvements in both physical and mental function to patients with hip osteoarthritis and poor mental health, though overall scores remain lower than in those with better mental health.

Severe patellofemoral arthritis does not compromise 6-month post-operative range of motion or function following unicondylar knee arthroplasty.

BACKGROUND: The presence of significant patellofemoral arthritis (PFA) is still considered a contraindication for unicondylar knee arthroplasty (UKA) by many surgeons. The purpose of this study was to determine if the presence of severe PFA at the time of UKA compromised early (< 6 months) post-operative knee range of motion or functional outcomes. METHODS: This retrospective review evaluated unilateral and bilateral UKA (323 patients; 418 knees) between 2015 and 2019. Procedures were grouped by degree of PFA present at the time of surgery, including mild PFA (Group 1; N = 266), moderate to severe PFA (Group 2; N = 101), and severe PFA with lateral compartment bone-on-bone contact (Group 3; N = 51). Knee range of motion and Knee Society Knee (KSS-K) and Function (KSS-F) scores were collected both before and at 6 months following surgery. Group differences were evaluated with Kruskal-Wallis and Chi-square tests for continuous and categorical variables, respectively. Univariate and multivariable logistic regressions were performed to determine influential variables associated with post-operative knee flexion being ≤ 120° and presented as odds ratios (OR) and 95% confidence intervals (CI). RESULTS: Pre-operative flexion was lowest in Group 3 (p = 0.010) with 17.6% of knees having flexion ≤ 120°. Post-operative flexion was lowest in Group 3 (119.1° ± 8.4°, p = 0.003) with 19.6% knees having flexion ≤ 120° compared to 9.8% and 8.9% in Groups 1 and 2, respectively. No significant difference in KSS-F following surgery was found; all three groups demonstrated similar clinical improvement. Increased age (OR 1.089, CI 1.036-1.144; p = 0.001) and body mass index (OR 1.082, CI 1.006-1.163; p = 0.034) were found to be associated with post-operative knee flexion ≤ 120°, while high pre-operative flexion (OR 0.949, CI 0.921-0.978; p = 0.001) was found to be inversely associated with poor knee flexion following surgery. CONCLUSION: Patients with severe PFA demonstrate similar clinical improvement following UKA at 6 months as patients with less severe PFA.

Higher intra-operative narcotic requirements and weakness with quadratus lumborum compared to paravertebral nerve block for total hip arthroplasty.

BACKGROUND: This was a prospective single-blinded study comparing the peri-operative opioid consumption and motor weakness for patients undergoing total hip arthroplasty (THA) with either a Quadratus Lumborum Type 3 Nerve Block (QLB) or a Paravertebral Nerve Block (PVB). METHODS: A consecutive cohort of patients undergoing elective anterior approach (AA) THA by a single high-volume surgeon were randomly assigned an anesthesiologist by the charge anesthesiologist. One anesthesiologist performed all QLBs, and the other six anesthesiologists performed the PVBs. Pertinent data include prospectively collected qualitative surveys from blinded medical personnel, floor nurses, and physical therapists as well as demographic information and post-operative complications. RESULTS: Overall, 160 patients were included in the study divided equally between the QLB and PVB groups. The QLB group had a statistically higher peri-operative narcotic use (p < 0.001), greater intra-operative peak systolic blood pressure (p < 0.001) and respiratory rate (p < 0.001), and higher incidence of post-operative lower extremity muscle weakness (p = 0.040). There were no statistical group differences for floor narcotic use, post-operative hemoglobin levels or hospital length of stay. CONCLUSION: The QLB required greater intraoperative narcotic use and resulted in greater post-operative weakness, however provided nearly equal post-operative pain management and did not adversely affect rapid discharge success. LEVEL OF EVIDENCE: III, Non-randomized controlled cohort/follow-up study.

Influence of obesity and intra-operative imaging guidance technology on acetabular cup positioning in total hip arthroplasty.

BACKGROUND: Accuracy of acetabular cup positioning during total hip arthroplasty (THA) can be improved with intra-operative imaging but may be influenced by body mass index (BMI). This study assessed the influence of BMI (kg/m2) on cup accuracy when using intra-operative fluoroscopy (IF) alone or supplemented with a commercial product. METHODS: This retrospective review included four consecutive cohorts of patients having undergone anterior approach THA with IF alone (2011-2015), IF and Overlay (2015-2016) (Radlink Inc., Los Angeles, CA), IF and Grid (2017-2018) (HipGrid Drone™, OrthoGrid Systems Inc., Salt Lake City, UT) and IF and Digital (2018-2020) (OrthoGrid Phantom®, OrthoGrid Systems, Inc., Salt Lake City, UT). Component placement accuracy was measured on 6-week post-operative weight bearing radiographs and compared between four BMI patient groups (BMI ≤ 25, 25 < BMI ≤ 30, 30 < BMI ≤ 35, and 35 < BMI). Total fluoroscopy times were also recorded directly from the fluoroscopy unit. RESULTS: Abduction angle significantly increased as BMI increased (p = 0.003) with IF alone but no difference was present in groups with guidance technology. Anteversion was significantly different between BMI groups for IF alone (p = 0.028) and Grid (p = 0.027) but was not different in Overlay (p = 0.107) or Digital (p = 0.210). Fluoroscopy time was significantly different between BMI categories for IF alone (p = 0.005) and Grid (p = 0.018) but was not different in Overlay (p = 0.444) or Digital (p = 0.170). CONCLUSION: Morbid obesity (BMI > 35) increases risk for malpositioning of acetabular cups and increases surgical time with IF alone or the Grid. Additional IF guidance technology (Overlay or Digital) increased cup positioning accuracy without decreasing surgical efficiency.

Preoperative Educational Classes in Elderly Patients May Not be Necessary Prior to Elective Joint Arthroplasty.

Preoperative arthroplasty classes decrease complications and readmissions, however, in-person classes are inconvenient for elderly patients with mobility limitations. This retrospective review included 232 patients (305 joints) with in-person preoperative educational classes (IPC) and 155 patients (192 joints) with telephone preoperative educational classes (TC). Compared to IPC, TC patients had a shorter length of stay (P<.009), but a greater percentage made at least one postoperative clinic call (22.8% vs 40%; P<.001). No differences were noted in complications, but emergency room visits significantly decreased for total knee TC patients (P=.039). The increase in clinic calls may be addressed through focused changes to the preoperative telephone dialogue, providing a safe and efficient alternative to IPCs.

True "outpatient discharge" following single-stage bilateral unicompartmental knee arthroplasty may be unrealistic for most.

BACKGROUND: Single-stage bilateral unicompartmental knee arthroplasty (BUKA) has shown post-operative function and cost benefits over staged bilateral procedures, without increased complications. A rapid discharge protocol at the current study site has reported outpatient discharge for the unilateral procedure exceeding 97%. However, the feasibility of outpatient discharge following BUKA remains unclear. Therefore, the purpose of this study was to determine the success of achieving outpatient (< 24 h) discharge following BUKA, and identify patient variables associated with failure. METHODS: A retrospective chart review was completed for 104 BUKA patients. All patients with bilateral, symptomatic unicompartmental knee arthritis were offered the single-stage procedure. Data collection included patient demographics, discharge status, and disposition location. Independent t tests (continuous) and Chi-squared tests (categorical) determined differences between discharge (outpatient/inpatient) and disposition (home/other) groups. Variables associated with discharge status and location were assessed with multivariable regression. RESULTS: While 96 (92.3%) patients discharged within 24 h, only 63.5% were able to discharge directly home. Patients requiring a longer hospital stay (> 24 h) were more likely to require a pre-operative assistive device (62.5% and 25.0%, p = 0.037) and live alone (37.5 vs 8.3%, p = 0.033). For those discharged within 24 h, living alone significantly increased the risk (odds ratio: 5.800, p = 0.038) of requiring an acute inpatient facility prior to transition home. CONCLUSION: Achieving "true" outpatient discharge is only modestly successful for most BUKA patients, as many required an acute inpatient or short-term rehabilitation facility prior to returning home. BUKA should be differentiated from the unilateral procedure regarding outpatient discharge expectations. LEVEL OF EVIDENCE: III, Case-control study; Retrospective comparative study.

Prevalence of invalid ImPACT baseline test results among high school athletes with invalidity and sandbagging indices.

Objective: The comparison of baseline neuropsychological test results with post-concussion neuropsychological test results is a common practice to assess the aftermath of a sport-related concussion. The effectiveness of this approach is compromised when invalid baseline test performances occur. The present study was designed to assess the prevalence of invalid baseline test results of high school athletes, using the Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT). Method: A large sample of 8938 high school athletes' baseline test data were examined, including the four ImPACT Composite scores and three sets of embedded invalid indices: five ImPACT Invalidity Indicators, four ImPACT sandbagging red flags, and two ImPACT sandbagging subtest flags. Results: There were 8394 (93.91%) Valid scorers, who failed no Invalidity Indicators; 544 (6.09%) Invalid scorers, who failed at least one Invalidity Indicator, 2718 (30.41%) Red Flag scorers, who had at least one Red Flag score; and 4154 (46.47%) Subtest Flag scorers, who had at least one Subtest Flag score. Of the entire sample, 4485 (54.65%) failed at least one of the invalid indices. Conclusions: As in prior studies of high school athletes, the Invalidity Indicators identified a low portion (6.09%) of the athletes with invalid baseline test results, while other invalidity measures found 30.41% to 46.48% of the athletes producing questionable test results. The high rate of invalid test findings suggested in this research calls for greater efforts to improve the accuracy of baseline test results.

Impact of intraoperative fluoroscopic beam positioning relative to the hip and pelvis on perceived acetabular component position.

Background: Parallax is poorly understood and can mislead surgeons using intraoperative fluoroscopy (IF) to guide cup placement during anterior approach (AA) total hip arthroplasty. The purpose of this study was to examine how changes in fluoroscopic beam positioning in relation to the hip and pelvis affects the projected acetabular image. Methods: An acetabular component was positioned in an anatomic pelvis model in 45° and 20° of abduction and anteversion, respectively using a computer assisted cup targeting system. Fluoroscopic images were taken at various caudal and cranially directed angles with the fluoroscopic beam centered over the hip then pelvis. In each position, four independent observers measured the abduction and anteversion angles of the projected cup image using the same computer targeting system. Results: Cup abduction and anteversion measured 43.5° and 19.5° when IF was centered over the hip and 40.5 and 27.5° when centered over the pelvis in the neutral position. Increasing the caudal direction of the beam 20° increased the projected abduction/anteversion angles by approximately 7°/12° and 9°/16° when centered over the hip and pelvis respectively. Increasing the cranial direction of the beam 20° decreased the measured abduction/anteversion angles by roughly 4°/20° and 4°/24° when centered over the hip and pelvis, respectively. Conclusion: The projected image of the acetabular component can change dramatically depending on fluoroscopic beam position relative to the hip and pelvis. Recognizing the approximate direction and magnitude of change with differing fluoroscopy positions may help surgeons avoid cup malpositioning.

Rapid Analysis of ADP-Ribosylation Dynamics and Site-Specificity Using TLC-MALDI.

Poly(ADP-ribose) polymerases, PARPs, transfer ADP-ribose onto target proteins from nicotinamide adenine dinucleotide (NAD+). Current mass spectrometric analytical methods require proteolysis of target proteins, limiting the study of dynamic ADP-ribosylation on contiguous proteins. Herein, we present a matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) method that facilitates multisite analysis of ADP-ribosylation. We observe divergent ADP-ribosylation dynamics for the catalytic domains of PARPs 14 and 15, with PARP15 modifying more sites on itself (+3-4 ADP-ribose) than the closely related PARP14 protein (+1-2 ADP-ribose)─despite similar numbers of potential modification sites. We identify, for the first time, a minimal peptide fragment (18 amino-acids) that is preferentially modified by PARP14. Finally, we demonstrate through mutagenesis and chemical treatment with hydroxylamine that PARPs 14/15 prefer acidic residues. Our results highlight the utility of MALDI-TOF in the analysis of PARP target modifications and in elucidating the biochemical mechanism governing PARP target selection.