Abstract: BACKGROUND: Poor prognosis of hip arthroplasty in patients with osteoporosis seriously affects the patients’ quality of life. Accurately predicting the risk factors for poor prognosis of hip arthroplasty in patients with osteoporosis remains a major challenge for orthopedic surgeons.
OBJECTIVE: To explore risk factors for poor prognosis after hip arthroplasty in patients with osteoporosis and construct a Nomogram prediction model. 
METHODS: A total of 192 patients with osteoporosis who underwent hip arthroplasty in Nanyang Second People’s Hospital from July 2020 to June 2022 were selected as study subjects. Harris hip function scale was performed 6 months after operation. Patients with Harris score ≥ 80 were included in the good prognosis group (n=142), while patients with Harris score < 80 were included in the poor prognosis group (n=50). Clinical data of the two groups were collected and subjected to univariate analysis. Receiver operating characteristic curves were used to analyze the predictive value of the measures for poor prognosis after hip arthroplasty in patients with osteoporosis. Binary logistic regression was used to analyze the risk factors affecting poor prognosis after hip arthroplasty in patients with osteoporosis. The Nomogram prediction model for poor prognosis after hip arthroplasty in patients with osteoporosis was constructed. The calibration curve was internally validated and the concordance index was calculated, and the decision curve was evaluated for clinical predictive efficacy. 
RESULTS AND CONCLUSION: (1) The differences between the two groups were statistically significant in terms of age, body mass index, operative time, intraoperative bleeding, serum albumin, peripheral blood lymphocyte count, prognostic nutritional index, and complications (P < 0.05). (2) Area under the curve for age, body mass index, operative time, intraoperative bleeding, serum albumin, peripheral blood lymphocyte count, and prognostic nutritional index were 0.813, 0.780, 0.787, 0.764, 0.777, 0.785, and 0.818. (3) Age, body mass index, intraoperative bleeding, and complications were risk factors for poor prognosis after hip arthroplasty in patients with osteoporosis. (4) The corrected, raw curve of the nomogram prediction model was close to the ideal curve with a concordance index of 0.851 (0.815-0.886) and a good model fit, with a threshold of > 0.12 for the Nomogram prediction model to provide a net clinical benefit, and all net clinical benefits were higher than the independent predictors. (5) It is concluded that age, body mass index, intraoperative bleeding, and complications are risk factors affecting the poor prognosis of osteoporotic patients after hip arthroplasty. The Nomogram prediction model constructed based on this can help clinicians assess the prognosis of osteoporotic patients after hip arthroplasty, develop personalized interventions, improve prognosis, and enhance the quality of life.

Key words: osteoporosis, hip arthroplasty, prognosis, Nomogram prediction model, complication