Long-term follow-up of hypothenar hammer syndrome: a series of 47 patients

Hypothenar hammer syndrome (HHS) is an uncommon form of secondary Raynaud phenomenon, occurring mainly in subjects who use the hypothenar part of the hand as a hammer; the hook of the hamate strikes the superficial palmar branch of the ulnar artery in the Guyon space, leading to occlusion and/or aneurysm of the ulnar artery. In patients with HHS, such injuries of the palmar ulnar artery may lead to severe vascular insufficiency in the hand with occlusion of digital artery. To date, only a few series have analyzed the long-term outcome of patients with HHS. This prompted us to conduct the current retrospective study to 1) evaluate the prevalence of HHS in patients with Raynaud phenomenon and 2) assess the short-term and long-term outcome in patients with HHS. From 1990 to 2006, 4148 consecutive patients were referred to the Department of Internal Medicine at the University of Rouen medical center for evaluation of Raynaud phenomenon using nailfold capillaroscopy. HHS was diagnosed in 47 of these 4148 patients (1.13% of cases).Forty-three patients (91.5%) had occupational exposure to repetitive palmar trauma. The more common occupations were factory worker (21.3%), mason (12.8%), carpenter (10.6%), and metal worker (10.6%); the mean duration of occupational exposure to repetitive palmar trauma at HHS diagnosis was 21 years. One patient (2.1%) had recreational exposure (aikido training) to repetitive trauma of the palmar ulnar artery, and 3 other patients (6.4%) developed HHS related to a single direct injury to the hypothenar area. Clinical manifestations were more often unilateral (87.2%) involving the dominant hand (93%). HHS complications included digital ischemic symptoms (ischemia: n = 21, necrosis: n = 20) and irritation of the sensory branch of the ulnar nerve (n = 11). In HHS patients, angiography demonstrated occlusion of the ulnar artery in the area of the Guyon space (59.6%), aneurysm of the ulnar artery in the area of the Guyon space (40.4%), and embolic multiple occlusions of the digital arteries (57.4%). All patients were advised to change their occupational exposure. They were given vasodilators, including calcium channel blocker (n = 37) and buflomedil (n = 12); 36 patients (76.6%) also received oral platelet aggregation inhibitors. Twenty-one patients with digital ischemia/necrosis were further given hemodilution therapy to reduce the hematocrit level to 35%. In 3 patients with HHS-related digital necrosis who exhibited partial improvement with vasodilators, prostacyclin analog therapy (a 5-day regimen of intravenous prostacyclin analog) was instituted, resulting in complete healing of digital ulcer in these 3 patients. Other conservative treatment options included controlling risk factors (smoking cessation, low-lipid diet, therapy for arterial hypertension) and careful local wound care of fingers in the 20 patients with digital necrosis. Only 2 patients, exhibiting digital necrosis and multiple digital artery occlusions, with nonthrombotic ulnar artery aneurysm underwent reconstructive surgery, that is, resection of the aneurysm with end-to-end anastomosis of the ulnar artery. The median length of follow-up in patients with HHS was 15.9 months. Thirteen patients (27.7%) exhibited clinical recurrences of HHS; the median time of HHS recurrence onset was 11 months. Outcome of HHS relapse was favorable with conservative measures in all cases. Awareness of HHS is required to increase suspicion of the disorder so that further exposure to risk factors like repetitive hypothenar trauma can be avoided for these patients; this is of great importance for their overall prognosis. We found favorable outcomes in most patients after conservative measures were initiated; therefore we suggest that surgery may be undertaken in the subgroup of patients who exhibit partial improvement while receiving conservative therapy. Finally, because we observed recurrence of HHS in 27.7% of patients, we note that HHS patients require close follow-up, including both regular and systematic physical vascular examination.