Scaphoid malunion.

Forty-five patients with 46 scaphoid fractures were studied more than 6 months after union by clinical examination and trispiral tomography. Twenty had normal scaphoid alignment with lateral intrascaphoid angles less than 35 degrees; the rest had varying degrees of increased flexion angulation of the scaphoid, ranging from 36 degrees to 60 degrees. Increasing lateral scaphoid angulation, eventually resulting in a "humpback" deformity, was associated with progressively poor clinical and radiographic results. There were satisfactory clinical outcomes in 83% and posttraumatic arthritis in only 22% of those with normal scaphoid anatomy. Those with greater than 45 degrees of lateral intrascaphoid angulation present at the time of union had a satisfactory clinical outcome in 27% and posttraumatic arthritis in 54%. Union alone is an insufficient criterion for success in treating scaphoid fractures.