Introduction: Distal forearm fractures in younger adults are rare injuries resulting from high energy trauma. Treatment options vary from cast fixation, external fixator, percutaneus pinning and open reduction and internal fixation.
Method: We retrospectively reviewed 13 patients aged 18-59 from 1996 to 2005 with a distal unstable forearm fracture. All were treated with open reduction and internal fixation of the radius. The ulna was stabilized either by an open reduction and internal fixation or by a closed reduction with or without pin fixation and cast fixation in all cases. At follow-up, we evaluated the radiologic results in terms of forearm fracture retention and functional outcome according to the wrist score by Krimmer.
Result: Radial inclination amounted to 24 degrees at the injured side when compared to 27 degrees at the non-injured side, palmar tilt was 3 degrees versus 7 degrees and ulna variance was -2 versus -1 mm. According to the modified wrist score by Krimmer, seven excellent, two good and four fair results were achieved. The range of motion of the injured wrist joint was 149 degrees of rotation, in the sagittal plane 106 degrees , frontal plane 61 degrees and on the non-injured side rotation was 171 degrees , and movement in the sagittal plane was 146 degrees and 79 degrees in the frontal plane. Decreased forearm rotation (107 degrees vs. 162 degrees ) and decreased range of motion in the sagittal plane (77 degrees vs. 114 degrees ) were measured in patient following open reduction and internal fixation of radius and ulna compared to the outcome in patients with open reduction and internal fixation of the radius and closed reduction of the ulna. Grip strength of the injured side averaged 350 N versus 440 N which is 76% of that of the opposite side. All patients stated no pain at rest and some experienced slight pain at work. Three patients had an excellent performance at daily activities, nine patients presented problems with certain activities, and one patient showed severe limitations.
Conclusions: Open reduction and internal fixation of the radius is the keystone in treating distal forearm fracture. In case of stable retention of the ulnar head after closed reduction, cast fixation with or without percutaneus pin fixation is a sufficient method to treat unstable distal forearm fractures. In patients with remaining instability of the distal ulna fracture, ORIF is indicated.