Hemoglobin level, degree of mobilization, and pneumonia are associated with the development of postoperative delirium in cemented hemiarthroplasty after femoral neck fracture.

Purpose: The aim of this retrospective study was to identify independent prognostic factors for developing a postoperative delirium (POD) in patients suffering from a proximal femoral neck fracture and treated by implantation of a hemiprosthesis.

Methods: A retrospective study, including patients with hip hemiarthroplasty due to a femoral neck fracture between 2011 and 2020 was performed. Demographic data, preexisting conditions, intra-/postoperative complications, mobilization and laboratory results were extracted from the patients' charts. The different parameters were analyzed comparing patients with and without POD.

Results: 412 patients, mean age of 81 ± 9.58 years were included, 66.5% (n = 274) were female, 18.2% (n = 75) of them developed a POD. Significantly higher incidence of POD was associated with older age (p < 0.001), lower level of haemoglobin (p < 0.001), higher post-surgery interleukin 6 (IL 6) level (p = 0.008), higher postoperative level of leukocytes (p = 0.01). Patients with POD received more units of packed red blood cells (PRBC) (p = 0.007). Patients with no mobility limitations pre-operatively developed POD less frequently (p = 0.01), whereas suffering from pneumonia (p = 0.03) or limited mobility postoperatively increased the risk of POD (p < 0.001).

Conclusion: This study could help to identify patients with a risk for developing POD after a hemiarthroplasty in femoral neck fractures. As a consequence, frequent controls of Hb, IL 6 and leucocytes levels to avoid anemia and infections, as well as the well surgical treatment to guarantee a good postoperative outcome.