The "floating ulna" injury in adults: a case report, literature review and proposed injury classification.

Background: Ipsilateral Galeazzi fracture with elbow dislocation, namely the "floating ulna" injury, is a rare injury pattern. A few reports have described this type of injury and its treatment.

Case Presentation: A 33-year-old female at 38 weeks gestational age presented with Galeazzi fracture and posterolateral elbow dislocation of the left upper extremity. The patient was treated with closed reduction of the elbow, open reduction, and internal fixation of the radial shaft fracture with a dynamic compression plate and K-wire stabilization of the unstable distal radioulnar joint. At the 12-month follow-up, the patient had no pain or signs of instability. Range of motion was 0-135° at the elbow, 70° extension and 80° flexion at the wrist, and 80° supination and 80° pronation at the forearm.

Conclusion: The "floating ulna" injury is a rare and special injury pattern with ipsilateral Galeazzi fracture and elbow dislocation. This type of injury was likely caused by significant amount of deforming force and the unique position of upper limb when the patient fell from a height of 1-2 m in high-energy trauma.