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.

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.

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.

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.

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.