Patients with pre-existing neurologic disorders present a unique set of challenges for shoulder arthroplasty (SA) surgeons due to the presence of concomitant contractures, muscle weakness, and spasticity, which may affect outcomes and complication rates after shoulder arthroplasty. The goal of this systematic review was to evaluate the clinical and functional outcomes after SA in patients pre-existing with neurologic disorders, focusing on complication and reoperation rates. This systematic review was performed in adherence to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines outlined by Cochrane Collaboration. A search of PubMed, the Medline Library, and EMBASE from inception until September 2023 was conducted to obtain studies reporting on outcomes after SA in patients with neurological disorders. Study demographics and information on outcomes including patient-reported outcomes and complication rates were collected. The methodological quality of included primary studies was appraised using the MINORS scoring system. Twenty articles published between 1997 and 2023 met inclusion criteria. In total, 13,126 patients with neurological conditions with 7 different neurological disorders (Parkinson's disease (PD), epilepsy and seizures, cerebral palsy (CP), poliomyelitis, Charcot neuropathy (CN), cerebrovascular disease (CVD) and multiple sclerosis (MS)) were included. The mean patient age was 64.3 years (range, 33.0 - 75.8 years), 51.4% of patients were male, and the mean postoperative follow-up time was 5.1 years (range, 1.4 - 9.9 years). PD was the most reported neurological disorder (9 studies, 8,033 patients), followed by epilepsy (4 studies, 3,783 patients), and MS (1 study, 1,077 patients). While these patients did experience improvements in outcomes following SA, high complication and revision rates were noted. Patients with neurologic disorders demonstrate improvements in pain and function after SA but have higher reported complication and revision rates when compared with patients without neurologic conditions. This systematic review offers valuable data for both the surgeon and patient regarding anticipated clinical results and possible complications from SA in patients with neurologic disorders that may aid in shared decision-making when considering SA.

Fisetin is a natural flavonoid that possesses antioxidant, anti-inflammatory, anti-senescence, and neuroprotective effects in preclinical studies. This double-blind randomized clinical trial investigated the effects of two fisetin dosing regimens on senescent gene expression in peripheral blood mononuclear cells (PBMCs) in elderly humans (> 55 years old). Participants were randomized to Daily dose (100mg/day, N = 41) or Bolus dose (20mg/kg for two consecutive days on and 28 days off, N = 40) for 60 days. Blood draw, PBMC isolation, RNA extraction and quantitative polymerase chain reaction (Q-PCR) for 5 target genes were performed at baseline, and days 15, 35, 45 and 60. At the primary endpoint, day 45, both fisetin dosing regimens significantly decreased galactosidase beta 1 (GLB1) and P16 ^INK4A (P16) gene expression. Bolus dose also significantly reduced macrophage migration inhibition factor (MIF) and alpha-L-fucosidase 1 (FUCA1) compared to baseline and decreased MIF compared to daily dose. Further, Bolus dose significantly decreased GLB1 and MIF at days 15, 35, 60, and P16 at days 15, 35 as well as FUCA1 at day 35 compared to baseline. Hence, Bolus dosing of fisetin is more effective than Daily dosing for reducing cellular senescent genes in PBMCs isolated from elderly human blood.