Risk factors for elbow stiffness after surgery for AO / OTA type C distal humerus fractures.

OBJECTIVE

The aim of this study is to identify risk factors for elbow stiffness following surgery for AO/OTA type C distal humerus fractures with a follow-up investigation.

METHODS

Data were collected from patients who underwent treatment for AO/OTA type C distal humerus fractures between March 2015 and March 2022.The patients were divided into a stiffness group and a control group based on whether their elbow flexion-extension or rotation range of motion was less than 100°at the final follow-up. Univariate analysis and multivariate logistic regression analysis was performed to identify independent risk factors. A nomogram prediction model was then constructed based on the factors identified. Receiver operating characteristic (ROC), calibration curve and decision curve analysis (DCA) were used to evaluate its discriminant and calibration. The subjects were randomly divided into modeling set and validation set according to 7:3, and the model was internally validated by random split validation.

RESULTS

Of the 207 patients, 68 developed elbow stiffness after ORIF for AO/OTA type C distal humerus fracture. Multivariate logistic regression analysis identified age,AO/OTA fracture classification,time from injury to surgery,postoperative professional functional rehabilitation, transverse screw,and modified trochleocapitellar index (mTCI), as independent risk factors for postoperative elbow stiffness (all P < 0.05). The modeling set curve demonstrated an AUC value of 0.877, while the validation set curve showed an AUC of 0.869. The calibration curve of the nomogram closely approximated the diagonal line, and decision curve analysis (DCA) revealed that utilizing the nomogram for prediction yielded greater net benefits within the threshold probability range of 0.3-0.8.

CONCLUSION

Age, AO/OTA type C classification, transverse screw, postoperative professional functional rehabilitation, mTCI and time from injury to surgery were identified as risk factors for postoperative elbow stiffness.