Evaluation of instability factors in distal radius fractures

Fractures of distal radius are one of the most common fractures seen by physicians and account for 20% of all fractures seen in the emergency room. Various factors contribute in secondary displacement of fracture fragments after anatomic or near anatomic close reduction and cast immobilization in distal radius fractures. This study was designed to examine the correlation between radiographic outcomes in the closed treatment of unstable distal radius fractures and different risk factors.

One hundred and fifty-seven patients were included in this prospective study. There were 107 women and 50 men; with a mean age of 51 ± 16.7 years (range: 20-86 years). During the follow-up in all radiographs, the following variables were analyzed as instability factors: (1) Age, (2) gender, (3) radial shortening, (4) dorsal comminution, (5) articular step-off, (6) radial inclination, (7) associated ulna fracture, and (8) dorsal angulation.

Based on the radiographic criteria for an acceptable reduction, 92 patients (58.6%) failed to maintain an acceptable reduction and classified as group I, while in 65 patients (41.4%), the postoperative radiographs were within an acceptable range and classified as group II. The mean age of patients in group I was higher than group II (P < 0.001). Radial shortening of more than 6.5 mm, loss of radial inclination of more than 6.5 degrees, and age above 52 at presentation were the most important predictive factors for instability.

Among the variables, the most important predictors of redisplacement after an acceptable closed reduction were loss of radial height, loss of radial inclination, and age.