Risk Factors of Flexor Tendon Rupture After ORIF of Distal Radius Fracture

Objectives: To analyze the risk factors associated with postoperative flexor tendon rupture, after a volar plate fixation of distal radius fractures. Design: Retrospective observational case–control study. Setting: Tertiary Care University Hospital in the Republic of Korea (2009–2020). Patients: Sixteen referred patients were treated for flexor tendon rupture, following previously performed volar plating of distal radius fractures at other institutions. 16 patients were randomly selected from our database as controls, and were matched based on the Soong grade of the case group. Intervention: Not applicable. Main Outcome Measurements: Radial tilt and radial height were measured on anteroposterior radiographs. The volar tilt, tear drop angle, carpal translation, and Soong grade were measured in a lateral view. Results: Quantitative measurements of the volar tilt, carpal translation, and tear drop angle were positively correlated with the flexor tendon rupture. The mean volar tilt and tear drop angle in the tendon rupture group were significantly smaller than those in the control group. The mean carpal translation in the tendon rupture group was significantly greater than that in the control group. Conclusions: This study demonstrated that volar tilt, carpal translation, and tear drop angle are significant risk factors for flexor tendon rupture, especially for plates placed at Soong grade 1 or 2. We suggest that the potential for tendon rupture because of incomplete reduction of the distal radius fracture along with implant prominence volar to the watershed line aggravates flexor tendon irritation at the distal edge of the plate because of distorted flexor tendon paths. Level of Evidence: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.