FURTHER INVESTIGATIONS OF THE INTRAOSSEOUS PRESSURE CHARACTERISTICS IN NECROTIC LUNATES (KIENBOCKS-DISEASE)

To confirm the hypothesis that venous congestion plays a role in idiop athic lunate necrosis (Kienbock's disease), intraosseous pressure in 1 2 normal and 12 necrotic lunates was measured. Intraosseous pressure i n the capitate of 12 healthy subjects served as reference measurement. The intraosseous pressure was recorded in neutral position and 60 deg rees extension of the wrist under normotensive conditions and during v enous stasis. In all groups, the mean intraosseous pressure rose signi ficantly with extension of the wrist, with the largest increase being 92.3 mmHg for necrotic lunates, followed by 40.3 mmHg for normal lunat es, 6.9 mmHg for normal capitates and during venous stasis, 26.6 mmHg for necrotic lunates, 26.1 mmHg for normal lunates, and 5.9 mmHg for n ormal capitates. In some necrotic lunates, the intraosseus pressure du ring extension exceeded the arterial blood pressure, which can be expl ained by mechanical deformation of the bone, In neutral position, no s ignificant differences in pressure were found between normal lunates a nd capitates. A significant difference was found for venous stasis and extension. The intraosseous pressure rise in the normal lunate in ext ension was slightly higher than the pressure found during venous stasi s. The intraosseous pressure differed significantly (by 56.9 mmHg) bet ween normal and necrotic lunates in extension. These data support the hypothesis that impairment of venous drainage plays a role in lunate n ecrosis and that the lunate can be considered as a venous bone at risk .