The study analyzed data from 157 patients undergoing knee surgery (TKA) to see how the type of anesthesia affects length of hospital stay. The researchers used an advanced machine learning method called Boruta's algorithm to identify the most important factors affecting hospital length of stay. They found that patients under general anesthesia (GA) stayed in the hospital for an average of 15.93 days, while patients under intrathecal anesthesia (IA) only 14 days. Borut's algorithm confirmed that the type of anesthesia is an important predictor of the length of stay together with the patient's age and pre-operative hospitalization. The analysis showed that general anesthesia was associated with longer anesthesia time, greater blood loss, and a higher need for transfusions, all factors associated with prolonged hospitalization. The authors conclude that the choice of intrathecal anesthesia for appropriate patients could potentially reduce the length of hospital stay and improve the efficiency of health care.