Postoperative cognitive changes after total knee arthroplasty under regional anesthesia

Area of Science:

• Anesthesiology
• Neuroscience
• Orthopedic Surgery

Background:

• Postoperative cognitive dysfunction following spinal anesthesia remains poorly understood.
• Total knee arthroplasty (TKA) provides an opportunity to investigate cognitive changes.
• Cerebrospinal fluid (CSF) biomarkers may offer insights into neurological effects.

Purpose of the Study:

• To identify the specific type of cognitive decline after TKA under spinal anesthesia.
• To evaluate changes in CSF biomarkers (amyloid peptide, tau, S100B) post-surgery.
• To assess the potential for neuronal damage associated with regional anesthesia.

Main Methods:

• Fifteen patients undergoing bilateral TKA at a 1-week interval under spinal anesthesia were enrolled.
• Neuropsychological tests assessing memory, executive function, and language were administered before each surgery.
• CSF levels of amyloid-beta 1-42, total tau, phosphorylated tau, and S100B were measured.

Main Results:

• Patients demonstrated significant decline in frontal-executive functions, including digit span and fluency, between assessments.
• A significant decrease in CSF S100B concentration was observed 1 week post-TKA.
• Trends towards decreased amyloid-beta, total tau, and phosphorylated tau were noted but not statistically significant.

Conclusions:

• Frontal-executive function impairment is a key characteristic of cognitive decline 1 week after TKA under spinal anesthesia.
• CSF biomarker data suggest that TKA performed under regional anesthesia does not appear to induce neuronal injury.