thenar hammer syndromeJoe Segen2016-12-30T12:45:28+00:00
thenar hammer syndrome
OCCUPATIONAL MEDICINE, ORTHOPAEDICS
An über rare condition that mimics rheumatic diseases, caused by repeated hammering motions made by the hand, typically seen in mechanics and certain bench labourers.
The thenar hammer syndrome–THS is less common than the hypothenar hammer syndrome–HHS. Both present with numbness, paraesthesia, Raynaud phenomenon, pain and in severe cases, trophic changes including callus formation, ulceration and tissue necrosis, but involve different sides of the hand.
The THS is due to obstructive injury of the distal radial artery and deep palmar arch and typically affects the thumb and index finger. In contrast, the HHS is due to obstructive lesions of the distal ulnar artery and superficial palmar arch and affects the remaining medial digits.
Patients with underlying arterial defects or incomplete palmar arches are more susceptible to these traumatic types of arterial injuries. Symptom severity reflects collateral flow through interconnected deep and superficial palmar arches.
Differential diagnosis Carpal tunnel syndrome, Raynaud phenomenon, hand synovitis
Diagnosis Angiography; B mode sonography reveals large, rounded, heterogeneous areas of hypoechoic and echogenic zones
References Joint Bone Spine. 2011 Mar;78(2):212-4
Occup Med (Lond) (October 2006) 56 (7): 507-509.