Abstract: BACKGROUND: Total hip and knee arthroplasty is widely used in the elderly population, but there is a lack of accurate prediction methods for unplanned readmission and postoperative complications.
OBJECTIVE: To investigate the effect of the Rothman index on unplanned readmission and complications in elderly patients undergoing total hip and knee arthroplasty.
METHODS: A total of 153 patients who underwent elective total hip and knee arthroplasty from December 2020 to December 2022 in Ward Area One, Department of Orthopedics, The First People’s Hospital of Zunyi were selected as the study subjects. According to whether they were unplanned readmission within 90 days after discharge, they were divided into a readmission group (n=21) and a non-readmission group (n=132). The general data of all patients were collected through the electronic medical record system, including gender, age, body mass index, diabetes mellitus, hypertension, and surgical joint type. The Rothman index was evaluated according to the literature. Postoperative complications were counted.
RESULTS AND CONCLUSION: (1) There was no significant difference in gender, body mass index, surgical joint type, and length of hospital stay between the readmission group and the non-readmission group (P > 0.05). There were significant differences in the number of comorbidities, age, and Rothman score between the two groups (P < 0.05). (2) The results of multivariate Logistics regression analysis showed that the number of comorbidities, age, and Rothman score were independent influencing factors for readmission 90 days after total hip and knee arthroplasty in elderly patients with hip and knee diseases (P < 0.05). (3) The results of receiver operating characteristic curve analysis exhibited that the area under the curve of the Rothman index for predicting readmission 90 days after total hip and knee arthroplasty was 0.824; the sensitivity was 80.85%; the specificity was 78.85%; the maximum Youden index was 0.597, and the optimal cutoff value was 46 points. (4) The incidence of total complications in elderly patients with Rothman < 46 was higher than that in elderly patients with Rothman ≥46 (P < 0.05). (5) It is concluded that the Rothman index can accurately predict unplanned readmission after total hip and knee arthroplasty in elderly patients with hip and knee joint diseases. Simultaneously, patients with Rothman index of less than 46 points have a higher overall risk of complications and poor joint recovery, which can be used to improve postoperative management of patients in clinical practice.

Key words: Rothman index, old age, artificial total joint arthroplasty, unplanned readmission, complication