To establish a prediction model for postoperative complications of intramedullary nail treatment for elderly intertrochanteric fractures and verify its effectiveness.

A retrospective analysis was conducted on the data of 451 patients with intertrochanteric fractures treated with intramedullary nails in our orthopedic department from January 2015 to December 2022. The average age was 81.97±7.91 years, including 129 males and 322 females, 135 patients with A1 type, 225 patients with A2 type, and 91 patients with A3 type. The patients were randomly assigned to a modeling group (338 cases) and a validation group (113 cases) in a 3:1 ratio. Using the modeling group data, logistic regression analysis was used to screen for independent risk factors for postoperative internal fixation complications, and a prediction model was constructed; Using validation group data, we analyzed its predictive performance using the subject work curve, and evaluate its fitting degree using Hosmer Lemeshow fitting toxicity test.

There were a total of 72 cases (15.9%) after surgery, including 16 cases (11 cases of INTERTAN, 5 cases of PFNA), 5 cases (1 case of INTERTAN, 4 cases of PFNA), 2 cases (1 case of INTERTAN, 1 case of PFNA), 17 cases (13 cases of INTERTAN, 4 cases of PFNA), and 32 cases (9 cases of INTERTAN, 24 cases of PFNA) of excessive withdrawal. Multivariate logistic analysis showed that unstable fractures, poor reduction quality, severe osteoporosis, PFNA, and weight-bearing time>4 weeks were independent risk factors for postoperative internal fixation complications (P<0.05). Based on the above indicators, a prediction model was constructed with a modeling group ROC curve area of 0.864, sensitivity and specificity of 0.882 and 0.7, respectively. The model fit was good (χ²=5.094, P=0.747). The area under the ROC curve of the validation group is 0.858, with sensitivity and specificity of 0.810 and 0.804, respectively. The Youden index is 0.614, and the model fits well (χ²=8.110, P=0.423).

Unstable fractures, poor reduction quality, severe osteoporosis, PFNA, and weight-bearing time>4 weeks are independent risk factors for postoperative internal fixation complications in the treatment of elderly intertrochanteric fractures with intramedullary nails. The predictive model established based on these indicators has good predictive performance.