Case Report: The Development of Delusional Jealousy Following Metal-on-metal Bilateral Hip Implant with Chronic Cobalt Toxicity

Abstract

<h3>Introduction</h3> More than 1 million arthroplasties are conducted annually worldwide, with 65% of patients aged 65 years and older. Complications include infection, dislocation, hypersensitivity reactions to metal implants, often requiring surgical re-intervention causing significant distress. Neuropsychiatric symptoms including dementia and depression secondary to chromium and cobalt toxicity with metal-on-metal implants have also been reported. These symptoms may persist even after removal of defective metal prostheses. Here we present a 51-year-old woman with delusional jealousy. She underwent bilateral hip arthroplasty following avascular necrosis X-12 years ago, with nine follow-up surgeries for complications. After getting lost in the orthopedist's office, and reporting memory lapses ultimately leading to a car accident in year X-2, she was diagnosed with neurocognitive disorder secondary to cobalt toxicity and depression by her orthopedist. Documented perioperative cobalt levels ranged from 5.6 to 14.9 µg/L (>1.0). She was treated with bilateral removal of the metal-on-metal implants. Ten months post-intervention, she attempted suicide by overdose on a lethal amount of pentazocine and naloxone. She claimed the overdose was secondary to stress caused by her husband's multiple romantic affairs. In the past 1-2 years, the patient had installed cameras in the house, accused her husband of hiding a girl under the table while washing dishes, repeatedly filed for divorce, and destroyed a motorcycle based on this claim. The patient was admitted to the psychiatric ward after medical clearance. <h3>Methods</h3> Case report. <h3>Results</h3> No significant focal deficits on her neurological examination. No major findings on her brain imaging. Her Montreal Cognitive Assessment was positive for mild neurocognitive deficits. Patient was started on lurasidone 20mg by mouth at bedtime. She refused any psychotropic medication treatment at discharge. <h3>Conclusions</h3> The final DSM-5 diagnosis was Delusional Disorder, Jealous type. Patient had metal-on-metal implant for 10 years with multiple complications prior to onset of neuropsychiatric symptoms. She had no prior psychiatric history other than mentioned above. The pathophysiology of delusional disorder may be associated to both organic and psychological stressors. Most commonly linked neurologic diseases are those affecting the basal ganglia and limbic systems. PET imaging studies in arthroprosthetic cobaltism have shown significant brain hypometabolism in these areas. Chronic, static damage by metallosis and multiple complications may have contributed to the delusional disorder. The dangerousness of delusional jealousy is also noteworthy. More research is necessary to understand the link between arthroplasty complications and delusional disorder. <h3>Funding</h3> None.