Hypothenar hammer syndrome: causes, sequelae and diagnostic aspects

Abstract

To investigate the reasons and disease course of Hypothenar Hammer Syndrome. Occlusion of the ulnar artery at the level of the hamate bone due to repetitive trauma to the hypothenar eminence is implicated as the cause of the rarely diagnosed hypothenar hammer syndrome (HHS). The thrombotic occlusion and the formation of an aneurysm of the ulnar artery and the superficial palmar arch with possible peripheral embolism of the digital arteries are a direct cause of the chronic damage to the vessel wall. Generally, HHS is diagnosed too late for recanalization to be a viable therapeutic option. From 1996 to 1998 the diagnosis of an HHS was made in 8 patients at our hospital. Etiology, clinical settings and disease course were assessed. Our analysis suggests that HHS may be caused by a single severe trauma in addition to repetitive injuries. The pathogenesis of the syndrome is dependent on the vascular anatomy of the individual hand. Interindividual variations in the arterial supply of the affected hand influences the clinical symptomatology with possible masking of arterial occlusions. An exact investigation concerning the pathogenesis of HHS is a precondition for treating the disease and may help to establish HHS as an occupational disease. MR-angiography may be a new approach for assessing HHS.