Background: Immunosuppressed patients are at an increased risk for developing odontogenic and orofacial infections, which can present with atypical processes and features that may mimic rare but life-threatening infections such as Ludwig’s angina. Differentiating cellulitis from a deep neck space infection is often challenging in this population in acute settings due to a broad differential diagnosis and blunted inflammatory responses. This diagnostic uncertainty complicates acute risk stratification and may delay recognition of conditions requiring early airway evaluation and intervention. Case Presentation: We present the case of a 28-year-old male with chronic myelogenous leukemia on immunosuppression with dasatinib who developed unilateral facial swelling and severe odontogenic pain that was refractory to empiric antibiotic therapy. The patient’s presentation with rapid clinical progression, early trismus, submandibular involvement, and floor-of-mouth tenderness raised significant concern for evolving Ludwig’s angina. Laboratory evaluation demonstrated elevated inflammatory markers, including erythrocyte sedimentation rate and C-reactive protein, further complicating early assessment. Imaging was promptly obtained to determine the nature of the infection, and the patient was admitted for intravenous antibiotic therapy and airway monitoring. Clinical improvement ensued. Conclusions: This case highlights the diagnostic overlap between facial cellulitis and Ludwig’s angina and underscores the importance of prompt imaging, airway monitoring, and clinical vigilance for risk stratification of immunocompromised patients in the acute setting to prevent life-threatening complications.

Aims: Revision total knee arthroplasty (rTKA) is a treatment option for failed primary TKA but is associated with higher complication rates and technical challenges. Robotic-assisted rTKA (rarTKA) is an emerging technique that may improve component alignment and surgical precision. However, its effect on early postoperative outcomes in rTKA for instability remains unclear. Methods: A total of 133 consecutive rTKAs for instability (82 manual and 51 robotic) performed by two fellowship-trained arthroplasty surgeons at a single institution were retrospectively analyzed. All rarTKAs used the MAKO robotic-arm system. Operating time, length of stay (LOS), joint line change, posterior condylar offset (PCO) change, and all-cause 30-/90-day complications were compared using univariable analyses. Revision implant constructs were also compared. The Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS-JR) and range of motion (ROM) were assessed at three months and one year, respectively. Kaplan-Meier analysis assessed one-year reoperation-free survival. Results: RarTKA achieved a greater mean increase in PCO (3.4 mm vs 1.5 mm; p = 0.014), but required a longer operating time (186 minutes vs 173 minutes; p = 0.037). Joint line change, LOS, three-month KOOS-JR, and ROM did not differ significantly. The 30-day (4.9% vs 7.8%) and 90-day (7.3% vs 11.8%) complication rates and one-year reoperation-free survival (91.5% vs 94.1%; p = 0.900) were comparable. Although offset couplers were not used, rarTKA constructs incorporated augments more frequently. Conclusion: RarTKA demonstrated early postoperative outcomes and complication rates comparable to those of conventional manual rTKA, while achieving improved PCO restoration despite longer operating times. LOS, functional outcomes, and one-year survivorship were similar between groups. Overall, rarTKA appears to be safe and effective; however, further investigation is required to determine the long-term benefits and clinical significance. Cite this article: Bone Jt Open 2026;7(8):1007–1014.

Autoimmune encephalitis (AE) represents a potentially reversible cause of subacute cognitive and psychiatric decline. When no autoantibodies are detected, seronegative AE remains diagnostically challenging, particularly among older adults presenting with new‐onset neuropsychiatric symptoms. This report describes an older adult with recurrent episodes of confusion, aphasia, and psychosis whose diagnostic studies—including magnetic resonance imaging (MRI) and cerebrospinal fluid (CSF) analysis—were unremarkable. The individual had previously demonstrated substantial improvement after corticosteroid therapy and was again treated empirically with immunotherapy following psychiatric consultation. This case highlights the importance of maintaining a high index of suspicion for AE when standard serologic markers are absent and underscores the collaborative role of psychiatry and neurology in evaluating rapidly progressive cognitive and behavioral syndromes, which may present initially as primary psychiatric illness. Early consideration of autoimmune etiologies and prompt initiation of immunotherapy can significantly improve outcomes in patients with otherwise unexplained, rapidly progressive cognitive or behavioral syndromes.

Herpes simplex virus type 1 (HSV‐1) encephalitis can mimic neurodegenerative or structural disorders, particularly in older adults presenting with cognitive or behavioral symptoms. We report the case of a 73‐year‐old woman with progressive gait instability, urinary incontinence, and cognitive decline, which was initially attributed to normal pressure hydrocephalus (NPH). Despite transient improvement after two lumbar punctures and neuroimaging suggestive of significant ventriculomegaly, the patient’s symptoms progressed with increasing paranoia, hallucinations, and agitation. Psychiatric consultation worked up the NPH diagnosis and identified various behavioral abnormalities—such as fluctuating delirium and psychosis—inconsistent with classic NPH. After 20 days of admission, restructuring of the differential and extensive infectious and metabolic testing led to the identification of HSV‐1 DNA in cerebrospinal fluid (CSF). The patient improved markedly with prompt acyclovir therapy. This case underscores the diagnostic overlap and mimicry between infectious and neurodegenerative processes and highlights the role of psychiatric input in reframing atypical neurocognitive presentations and expanding the differential of treatment‐resistant NPH in the presence of inconsistent symptomatic progression.

Traditional opiate immunoassays do not reliably detect fentanyl, and patterns of presumptive drug co-positivity in psychiatric emergency care remain poorly characterized. To describe class-specific urine drug screen positivity, quantify co-positivity among explicitly co-tested encounters, and assess the fentanyl testing gap among adult psychiatric emergency department encounters at two hospitals in West Virginia. We retrospectively analyzed 1,091 adult psychiatric emergency department encounters at two West Virginia hospitals from October 2020 through December 2024. Testing was clinician-directed. Class-specific estimates used only encounters tested for each class. Six-core-class co-positivity was assessed among 281 complete-panel encounters; complete and incomplete panels were compared. Multivariable logistic regression evaluated fentanyl and amphetamine/methamphetamine co-positivity among 350 co-tested encounters. Among tested encounters, tetrahydrocannabinol was positive in 214 of 513 (41.7%), amphetamine/methamphetamine in 203 of 509 (39.9%), and fentanyl in 146 of 519 (28.1%). Among complete-panel encounters, 128 of 281 (45.6%) were positive for at least two core classes. Substance-related chief complaints were more common among complete-panel encounters than among incomplete-panel encounters (73.3% versus 56.8%; p < .001). Among fentanyl-positive encounters co-tested for amphetamine/methamphetamine, 81 of 108 (75.0%) were also positive for amphetamine/methamphetamine. Amphetamine/methamphetamine positivity was associated with fentanyl positivity (adjusted odds ratio, 8.5; 95% confidence interval, 4.8-14.9). Among 118 fentanyl-positive encounters co-tested using the traditional opiate assay, 91 (77.1%) were opiate-screen-negative. Fentanyl and amphetamine/methamphetamine screens frequently overlapped in clinically selected subsets, and traditional opiate screening missed most fentanyl-positive screens. Psychiatric emergency services in fentanyl-affected regions should evaluate fentanyl-specific testing. Because immunoassays were presumptive and testing was nonprotocolized, findings represent screening yield, not confirmed exposure or population prevalence.

Fungal infective endocarditis is a rare but highly morbid condition commonly caused by Candida species. Candida parapsilosis is an uncommon cause of native valve endocarditis and is increasingly associated with healthcare exposure. We report a 50-year-old woman with persistent Candida parapsilosis candidemia complicated by large native aortic valve vegetations and acute limb ischemia from arterial embolization, requiring surgical valve replacement and prolonged antifungal therapy.