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Background and purpose Fatigue and cognitive difficulties are reported as the most frequently persistent symptoms in patients after mild SARS‐CoV‐2 infection. An extensive neurophysiological and neuropsychological assessment of such patients was performed focusing on motor cortex physiology and executive cognitive functions. Methods Sixty‐seven patients complaining of fatigue and/or cognitive difficulties after resolution of mild SARS‐CoV‐2 infection were enrolled together with 22 healthy controls (HCs). Persistent clinical symptoms were investigated by means of a 16‐item questionnaire. Fatigue, exertion, cognitive difficulties, mood and ‘well‐being’ were evaluated through self‐administered tools. Utilizing transcranial magnetic stimulation of the primary motor cortex (M1) resting motor threshold, motor evoked potential amplitude, cortical silent period duration, short‐interval intracortical inhibition, intracortical facilitation, long‐interval intracortical inhibition and short‐latency afferent inhibition were evaluated. Global cognition and executive functions were assessed with screening tests. Attention was measured with computerized tasks. Results Post COVID‐19 patients reported a mean of 4.9 persistent symptoms, high levels of fatigue, exertion, cognitive difficulties, low levels of well‐being and reduced mental well‐being. Compared to HCs, patients presented higher resting motor thresholds, lower motor evoked potential amplitudes and longer cortical silent periods, concurring with reduced M1 excitability. Long‐interval intracortical inhibition and short‐latency afferent inhibition were also impaired, indicating altered GABAB‐ergic and cholinergic neurotransmission. Short‐interval intracortical inhibition and intracortical facilitation were not affected. Patients also showed poorer global cognition and executive functions compared to HCs and a clear impairment in sustained and executive attention. Conclusions Patients with fatigue and cognitive difficulties following mild COVID‐19 present altered excitability and neurotransmission within M1 and deficits in executive functions and attention.

Background In total knee arthroplasty, the normal kinematics of the knee may not be restored solely based on preoperative gait, fluoroscopic-based, and dynamic radiostereometric analyses. Surgical technique case presentation This note introduced a 69-year-old male patient who sustained post-traumatic osteoarthritis of his right knee. He underwent robot-assisted total knee arthroplasty based on anatomical reproduction of knee stability during the swing phase of gait. The kinematic alignment was simply achieved within an easy-to-identified range after preoperative radiographic assessment, intraoperative landmarking and pre-validated osteotomy, and intraoperative range of motion testing. Conclusions This novel technique allows personalized and imageless total knee arthroplasty. It provides a preliminary path in reproducing the anatomy alignment, natural collateral ligament laxity, and accurate component placement within safe-to-identified alignment boundaries.