Cognitive impairment and postoperative outcomes in patients undergoing primary total hip arthroplasty: A systematic review.

STUDY OBJECTIVE

Total hip arthroplasty (THA) is a common surgical procedure in the elderly. Varying degrees of cognitive impairment (CI) are frequently seen in this patient population. To date, there has been no systematic review of the literature specifically examining the impact of CI on outcomes after elective THA. The aim of this systematic review was to identify studies that compare the postoperative outcomes of patients with and without CI after undergoing elective primary THA.

DESIGN

We conducted a systematic review of prospective and retrospective studies. A systematic literature review was conducted by searching MEDLINE, PubMed, and Embase from between January 1, 1997 and January 1, 2018. A total of 234 articles were reviewed and 22 studies were selected.

SETTING

Operating room and short-term and long-term postoperative recovery up to 2 years.

PATIENTS

Patients with CI who underwent an elective primary THA that required general anesthesia with a comparator group of patients who did not have dementia.

INTERVENTIONS

Patients who underwent elective primary total hip arthroplasty.

MEASUREMENTS

Outcomes included post-operative delirium (POD), mortality and other complications, discharge disposition, length of stay (LOS), mortality, short-term (30 days) and long-term (1 month-2 years) complications.

MAIN RESULTS

22 studies with 5,705,302 participants were included in the systematic review. Sample sizes varied greatly, ranging from 14 to 2,924,995 participants. There was an association between patients with CI and an increase in POD, in-hospital mortality, complications during hospitalization, non-routine disposition, LOS, mortality between 1 month to 2 years, and worse postoperative functional status.

CONCLUSIONS

We demonstrate that there are strong associations between patients with pre-existing CI undergoing THA and increased POD, hospital mortality, hospital complications, and hospital LOS. We report good quality evidence linking complications after THA to preexisting CI. Screening for CI can improve care and better predict the risk of developing postoperative complications such as delirium. Further investigations can address perioperative factors that can help reduce complications and show the utility of more widespread assessment of preoperative cognitive impairment.