[Apparent pseudarthrosis of the thumb].

Pseudarthrosis in the hand are defined as a non-union of a fracture after 6 month. Reasons might be biological disorders, mechanical instability or infection after fracture treatment. Pseudoarthrotic bone demands stable osteosynthesis and often bone grafting. The presented case is about a dislocated osseous fragment attached to the Aponeurosis dorsalis mimicking clinical and radiological a Pseudarthrosis of the proximal phalanx of the thumb. We would like to draw attention that osseous fragments may present very similarly to a pseudoarthrosis of a phalanx.