Faculty Bibliography

INTRODUCTION/BACKGROUND:Patellar resurfacing in primary total knee arthroplasty (TKA) has been debated for decades. This study aimed to evaluate cost-effectiveness and clinical outcomes of patellar resurfacing in modern TKA at a high-volume arthroplasty center. METHODS:A retrospective study was conducted on 4,534 patients who underwent unilateral, elective, primary TKA from 2021 to 2024 at an urban academic institute. Patients were stratified by patellar resurfacing: resurfaced (n=3,753) or not (n=781). Baseline characteristics, operative costs [implants, anesthesia, operating room time], and postoperative outcomes (revision incidence) were collected. The median follow up was 2.0 years (1.0- 4.8). The individual cost of patellar component was adjusted for implant manufacturer and cementation out of total implant cost. Multivariable regression analysis determined added operating room time (ORT) due to patellar resurfacing, controlling for body-mass index, usage of robotics, navigation and cementation. Relative costs of added ORT and the patellar component were compared to total implant and procedure costs of patellar-resurfacing operations. RESULTS:The patellar component accounted for an average of 7.9% of the total implant cost in patellar-resurfacing operations. Patellar-resurfacing operations had longer operative times (112.2 vs. 105.4 minutes, P<0.001), and multivariable regression determined patellar resurfacing is associated with an added 6.3 minutes of total ORT (P<0.001). The patellar component implant cost and the cost of added ORT due to resurfacing accounted for 4.5% of the total procedure cost in resurfaced group. Resurfaced group had an overall 5% higher total operative cost than the non-resurfaced group. No differences existed in length of stay (LOS), discharge disposition, or all-cause and patella-specific revision incidence. CONCLUSION/CONCLUSIONS:We found that patellar resurfacing was associated with longer operative times and greater implant and procedure costs, although there was no effect on LOS, discharge disposition, or all-cause and patella-specific revision incidence. Ultimately, the decision to resurface the patella in primary TKA should be based on patient-specific indications and clinical judgment. However, it is important to consider the additional cost associated with this procedure.

BACKGROUND/ INTRODUCTION/UNASSIGNED:Biologically inspired spiking neural networks can model adaptive behavior, but learning multiple goals is difficult because synaptic updates for different targets can interfere. We tested whether multi-timescale plasticity and context-specific credit assignment could improve continual multi-goal learning in a spiking navigation system inspired by entorhinal-hippocampal circuitry. METHODS/UNASSIGNED:We developed a closed-loop spiking model containing grid-like, place-like, target-related, association, and motor-output populations. An agent navigated in a two-dimensional environment with randomized starting locations and learned through reward-modulated spike-timing dependent plasticity (STDP/RL) and a novel evidence-gated plasticity (EGP) framework. EGP accumulates candidate synaptic modifications, evaluates them using reward evidence, and consolidates only changes that improve performance. A target-context variant maintained separate proposal stores and reward evaluation for each target. RESULTS/UNASSIGNED:STDP/RL learned and retained a single-target navigation policy, but multi-target training produced substantial interference, including attraction to incorrect targets after learning. Across 10 connectivity seeds, target-context EGP achieved higher late-stage reward than global EGP, improved weakest-target performance, and increased the fraction of targets achieving positive reward. In a longer continual-learning simulation, reward increased for all targets, TEST-phase performance increasingly exceeded TRAIN-phase performance, and proposal magnitudes grew over learning. Dwell-time confusion analyses showed that target-context EGP reduced wrong-target attraction and improved target selectivity relative to multi-target STDP/RL. CONCLUSIONS/UNASSIGNED:These results demonstrate that spiking navigation circuits can learn goal-directed behavior using local plasticity, but robust multi-goal learning benefits from context-specific evidence-based consolidation. Target-context EGP provides a biologically motivated mechanism for reducing interference during continual reinforcement learning in spiking neural networks.

Lupus nephritis (LN), a severe manifestation of systemic lupus erythematosus (SLE), is a heterogeneous disease driven by diverse immune and tissue cell types. We obtained 538,194 single-cell and 142,881 single-nuclear profiles from kidney biopsies of 155 patients with LN and 30 preimplantation transplant biopsy controls, along with 327,326 single-cell blood profiles. We characterized key stromal and immune cell types and cell states; moreover, we distinguished cell states that were tissue specific from those that were also present in the blood. We observed that LN pathological features were associated with particular cell states. For example, after controlling for the effects of chronic tissue damage, we observed that expansion of glomerular and scar-associated macrophage populations correlated with increasing inflammatory disease activity. Scar-associated macrophages appear to drive LN fibrosis and, in active disease, infiltrate the glomeruli more than other myeloid cells. These observations support that therapeutic targeting of myeloid populations may offer a strategy to prevent renal inflammation and ongoing kidney damage in LN.

Longitudinal causal inference is concerned with defining, identifying, and estimating the effect of a time-varying intervention on a time-varying outcome that is indexed by a follow-up time. In an observational study, Robins's generalized g-formula can identify causal effects induced by a broad class of time-varying interventions. Various methods for estimating the generalized g-formula have been posed for different outcome types, such as a failure event indicator by a specified time (e.g. mortality by 5 year follow-up), as well as continuous or dichotomous/multi-valued outcomes measures at a specified time (e.g. blood pressure in mmHg or an indicator of high blood pressure at 5-year follow-up). Multiply-robust, data-adaptive estimators leverage flexible nonparametric estimation algorithms while allowing for statistical inference. However, extant methods do not accommodate pooling estimation across time points when multiple outcomes are measured over time, which can lead to substantial loss of precision. We propose a novel multiply-robust estimator of the generalized g-formula that accommodates pooled estimation over numerous available outcome measures, which we refer to as time-smoothing. Our approach accommodates any intervention that can be described as a Longitudinal Modified Treatment Policy, a flexible class suitable for binary, multi-valued, and continuous longitudinal treatments. Our method produces an estimate of the effect curve: the causal effect of the intervention on the outcome at each measurement time, taking into account censoring and non-monotonic outcome missingness patterns. In simulations we find that the proposed algorithm outperforms extant multiply-robust approaches for effect curve estimation in scenarios with high degrees of outcome missingness and when there is low covariate overlap. We apply the method to study longitudinal effects of union membership on wages. The proposed estimator is available in the LMTP package at https://github.com/lmtp/tree/curve .

As demonstrated by Chuchvara et al. and a recent clinical case, amelanotic melanoma (AM) presents a diagnostic challenge for both clinicians and pathologists. AM is frequently clinically misdiagnosed due to its lack of pigmentation and clinical overlap with keratinocytic tumors and may mimic these neoplasms despite evaluation with advanced imaging techniques. These cases emphasize the importance of clinicopathologic correlation in lesions that are clinically amelanotic but histologically confirmed as melanoma.

Transradial access (TRA) has been increasingly utilized for cardiac catheterization. Pursuit of faster patient throughput has generated a need for more rapid hemostasis protocols that are safe, effective and affordable. Patients undergoing diagnostic cardiac catheterization using TRA at two tertiary-care centers were randomized to receive the standard of care procedure utilizing 5/6 French hydrophilic introducer sheath, with 50 units/kg of heparin during the procedure and a 2-hour hemostatic compression using a single-balloon device (Group 1), or 25 units/kg of heparin, with 1-hour hemostatic compression using a dual-balloon device capable of simultaneous ipsilateral ulnar artery compression (UC) (Group 2). The primary study endpoint was a composite of radial artery occlusion (RAO), rebound bleeding or hematoma formation. 451 patients were randomized: 224 in Group 1 and 227 in Group 2. A significant reduction in the primary endpoint was observed in Group 2 as compared with Group 1 (4% vs 10.3%, P = 0.01). Patent hemostasis was achieved in 97% of patients in Group 2, compared with 81% in Group 1 P = 0.001), with fewer nursing visits in Group 2 (5.3 ± 0.8 vs 3.1 ± 0.3, P = 0.001). Group 2 patients also achieved successful hemostasis with a significant reduction in duration of compression (mean reduction = 62 minutes, P = 0.001). In conclusion, a strategy of using a lower dose of heparin with UC achieves shorter duration hemostasis after TRA with significantly less rebound bleeding and RAO, as compared with the conventional strategy.

BACKGROUND AND OBJECTIVES/OBJECTIVE:Alzheimer's disease affects mostly women over 65, who make up nearly two-thirds of cases. Subjective cognitive complaints (SCC) can precede Alzheimer's disease by years. While physical activity supports healthy aging, the long-term impact of midlife physical activity (PA) on late-life SCCs in women is limited. RESEARCH DESIGN AND METHODS/METHODS:Using data from 4,397 participants (mean age=46.2 years at baseline; 78.7 years at SCC assessment) in the New York University Women's Health Study (NYUWHS), a prospective cohort of 14,274 women enrolled in 1985-1991, we examined the association between midlife PA and SCC reported nearly 30 years later. PA was assessed at baseline using self-reported weekly hours of mild, moderate, and vigorous activity, converted to metabolic equivalent hours per week (MET-hours/week). Odds ratios and 95% CIs were estimated using unconditional logistic regression, adjusting for demographics and midlife and late-life health conditions. Multiple imputation and inverse probability weighting addressed missing data and potential selection bias. RESULTS:Women in the highest tertile of total midlife PA had 20% lower odds of reporting ≥2 SCCs compared with those in the lowest tertile (OR = 0.80; 95% CI = 0.68-0.95). The inverse association was stronger among never smokers (OR = 0.68; p for interaction=0.029). The inverse association was consistent for moderate and vigorous, but not mild PA. Findings were consistent across sensitivity analyses using alternative SCC definitions, exclusion criteria, and inverse probably weights. DISCUSSION AND IMPLICATIONS/CONCLUSIONS:Higher level of midlife PA was associated with fewer late-life SCCs, suggesting that midlife PA may be an important behavioral correlate of later-life cognitive health in women.

PURPOSE/OBJECTIVE:Large language model-based artificial intelligence (AI) platforms have attracted substantial interest as potential clinical adjuncts within surgical specialties, particularly as patients have begun using AI for clinical advice. This study compared the management concordance of four commercially available AI platforms to practicing fellowship-trained hand surgeons using a series of clinical case vignettes within the field of hand surgery. METHODS:Nine hand surgery clinical vignettes with multiple-choice answer options were developed, including representative radiographs and clinical images. Four cases were classified as straightforward ("easy") and five as clinically complex ("hard"). The cases were then distributed anonymously to fellowship-trained hand surgeons from three institutions using an online survey. Four AI platforms were queried using a standardized prompt: ChatGPT-4 (OpenAI), Claude Opus 4.6 (Anthropic), Gemini (Google DeepMind), and Open Evidence. All AI platforms were accessed in March 2026. Each platform was queried once per case without regeneration to reflect real-world single-query usage. The primary outcome was concordance between each AI platform and the surgeon plurality response for each case. RESULTS:Fifteen fellowship-trained hand surgeons completed the survey. Surgeon consensus was high on easy cases (73% to 100% plurality agreement). All four AI platforms achieved concordance with the surgeon plurality on all four easy cases (100%). Performance diverged on complex cases: Claude Opus 4.6 and Gemini each achieved concordance on 3 of 5 complex cases (60%), whereas ChatGPT-4 and Open Evidence each achieved concordance on 1 of 5 (20%). Overall concordance was 7 of 9 (78%) for Claude Opus 4.6 and Gemini and 5 of 9 (56%) for ChatGPT-4 and Open Evidence. CONCLUSIONS:AI platforms were in agreement with surgeon responses in the majority of low-complexity cases, but had reduced agreement in clinically complex cases.

UNLABELLED:Pelvic fractures result in prolonged pain and immobility. In a randomized controlled trial of patients with pelvic fracture, whether abaloparatide (ABL) vs. placebo (PBO) improves healing at 3 months was evaluated. There was no significant difference in CT radiologic healing, physical performance, or change in pain in ABL vs. placebo. PURPOSE/OBJECTIVE:To determine if abaloparatide (ABL) vs. placebo (PBO) improves radiologic healing, pain, and functional outcome at 3 months in patients with pelvic fracture. METHODS:Postmenopausal women and men ≥ 50 years old, enrolled within 4 weeks of pelvic fracture (n = 48), were randomized to blinded ABL vs. PBO. The primary endpoint, fracture healing at 3 months, was assessed by two radiologists using a 5-point scale for cortical bridging from CT images comparing groups by Jonckheere-Terpstra test. The odds of healing (3 or 4 cortices bridged) were analyzed with Mantel-Haenszel relative risks (RR). Pain was assessed monthly by Numeric Rating Scale (NRS). The Short Physical Performance Battery (SPPB; walk speed, chair stands, and balance) evaluated functional mobility. RESULTS:Groups were balanced with a mean age = 82, 93% were female, 98% had multiple rami fractures, 67% had sacral fracture, and 36% had ≥ 1 displaced fracture. CT images at 3 months showed no significant difference in bridging score distribution (indicator of healing) in patients with ABL vs. PBO (p = 0.15) after adjusting for age, sacral fracture, displacement, or compliance. When evaluating individual fractures (n = 81), similar bridging scores were seen with ABL and PBO (p = 0.13). When patients were stratified as healed or not healed, 39% were healed with ABL and 64% healed with PBO (RR 0.61; 95% CI 0.33, 1.12). When looking at the 81 individual fractures, 47% were healed with ABL and 53% healed with PBO (RR = 0.88; 95% CI 0.55, 1.40). Using least square means controlling for age, sacral, and displaced fracture, NRS pain score was higher in the placebo than the ABL group at baseline (p < 0.05), but there were no further group differences in change in pain score SPPB and TUG scores improved over time in both groups without group differences. CONCLUSION/CONCLUSIONS:In this small study, there was no significant difference in CT radiologic healing, physical performance, or change in pain with ABL vs. placebo in patients with acute pelvic fracture. TRIAL REGISTRATION/BACKGROUND:ClinicalTrials.gov identifier: NCT04249232 registered January 27, 2020.