Published in:
01-05-2006 | Radiologic Anatomy
The hamate facet of the lunate: a radiographic study in an Arab population from Bahrain
Authors:
A. S. Dharap, H. Al-Hashimi, S. Kassab, M. F. Abu-Hijleh
Published in:
Surgical and Radiologic Anatomy
|
Issue 2/2006
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Abstract
Based on the presence of a facet for the hamate two types of lunate bone have been described in the wrist; type I is without a facet for the hamate while type II bears a facet on the medial surface for articulation with the proximal pole of the hamate. Compared to type I lunates, type II lunates have been shown to have different kinematics, are more prone to clinically relevant degenerative changes in the hamato-lunate joint and may cause ulnar-sided wrist pain. The incidence of type II lunates seems to vary in different populations. Postero-anterior (PA) view of plain radiographs of the hand was studied in Arab subjects from Bahrain (n=381; 307 males and 74 females) to determine the incidence of type I and type II lunates. The mean age of the subjects was 31.1 years, the range being 18–80 years. In the population studied, only 148 (38.8%) of the 381 wrists showed type II lunate; 121 (31.7%) were found in males and 27 (7.1%) in females. There was no significant difference in the mean age of subjects with type I or type II lunates (P=0.16). There was no correlation between side and gender with the presence or absence of a hamate facet on the lunate. The incidence of type II lunate was much lower than reports in the literature of populations from the Western world, which could be attributed to a genetic variation in the Arab population in Bahrain. These data indicate that osteoarthritis of the hamate or lunate is less likely to be a cause of ulnar-sided wrist pain in Bahraini Arabs.