Radiological risk factors for kienböck’s disease

Abstract

Hulten reported an association between Kienböck’s disease and ulnar minus variance in 1928. More recently the relevance of this finding in the etiology of Kienböck’s disease has been questioned. Several authors have found a change in the ulnar variance with age, sex, and position of the wrist as well as osteoarthritis secondary to Kienböck’s disease. It seems that the nature of the control group is crucial. Two meta-analyses recently conducted concluded that ulnar minus was not the origin of the Kienböck’s disease. A biomechanical study with finite element modelling demonstrated that ulnar minus variance was important for further progression of the collapse of the lunate. It is likely that ulnar minus variance is probably not the cause of Kienböck’s disease, but contributes to the further progression of the collapse of the lunate. Other factors that are associated with the pathogenesis or progression of Kienböck’s disease include a smaller lunate diameter and height, a more radially inclined lunate-tilting angle, and a flatter radial inclination. These anatomic factors may result in a greater load transmission across the lunate. Lunate morphology may also affect the severity of Kienböck’s disease at the time of initial presentation. The Viegas type 1 lunate wrists have significantly more advanced disease compared with those with type 2 lunates. If there is a type 1 lunate, then there is a greater chance that there will be a coronal fractures of the lunate; and in the absence of a coronal fracture, radioscaphoid angles are greater. Type II lunates appear to be protective against coronal fractures and scaphoid flexion deformities.