Case 13: Hypothenar hammer syndrome after minor injury to the hand
Keywords: Hypothenar hammer syndrome, vascular reconstruction, ulnar artery, vein graft, malperfusion syndrome hand
Authors: Frederik Kloss (MD), Vincent März (MD), Frederik Schlottmann (MD) and Peter M. Vogt (MD, Professor). MH Hannover, Germany
A 17 year old, male patient presented six weeks after a work-related, minor trauma to the left hand with an exertion related malperfusion syndrome of the fourth and fifth finger. Contemplating the clinical symptoms and initiated medical imaging the initial blunt crush injury with a drilling machine battery resulted in an aneurysmatic occlusion of the ulnary artery.
Before and after
Patient examination
17 year old, right handed male patient in good physical condition and professional training for a roofer. Symmetric configuration of the soft tissue with a centimeter long scar in the hypothenar region of the left hand. No muscular atophy. Fist closure, finger extension and spreading of the long fingers is powerful on both sides. The Phalen-Test is negative and there is no Hofmann-Tinel sign over the carpal canal or ulnar nerve sulcus. Isolated examination of the flexor- and extensor-tendons and a regular 2-point discrimination of 6 mm on all long fingers reveal no evidence of a sensomotoric deficit. The peripheral blood flow shows an ungual recapillarization time of
Pre-Operative Considerations
We treat a young patient with the need of utmost functionality regarding his age, physical fitness, personal aspirations and occupational requirements as a roofer. Hence, there is a need of evaluating the actual patency of the ulnar artery and considering conservative, as well as minimally invasive and open surgical methods. Providing the most accuracy we initiated an angiography also providing the therapeutic option of performing a simultaneous angioplasty, according to the extent and level of stenosis.
- Angiography: Reviewing the angiography the ulnary artery presents with a highgrade stenosis of the ulnary. Solely after warm-up of the left handy there was a minimal residual patency of the ulnar artery. While there was no prescence of the superficial palmar arch the profund palmar arch had a strong contrast filling. The arteries of the digitus IV and V on the other hand also presented with a reduced patency suggesting associated occlusions.
- Plan: Open Surgery remains the only possibility for a sufficient restoration of arterial flow to the ulnary fingers and patient consent was obtained for an open exploration of the vascularity of the hand and possible reconstruction of the ulnar artery with a vein graft.
- Patient Consent: The patient was given the information that the procedure may lead to an aggravation of symptoms and potential acral necrosis due to embolisms or ultimately the loss of fingers in case of a total and permanent occlusion.
Step 1: Pathological Allen Test (1)
Preoperative Allen Test demonstrates a malperfusion of the fingers.
- The bloodflow via the radial artery is manually suppressed
- The fingertips especially acral regions remain pale
Step 2: Pathological Allen Test (2)
The pressure on the radial artery is released and the perfusion of the fingers restored.
- The acral regions immediately assume a reddish tone.
Step 3: Preoperative markings
The y-shaped Millesi approach is chosen to gain optimal exposure of the palm with the possibility of extending the preparation to the fingers. Furthermore it may be combined with the classical ulnary approach to the loge de guyon.
- Ending in the commissure of the digitus IV/V, one may individually address either finger without risking skin perfusion.
- Shifting the classical Millesi approach slightly ulnary gives one the possibility to easily access the loge de guyon.
- Curved incisions along the palmar creases and over the rascetta provide a more natural scar appearance and reduce the risks of evolving contractures.
Step 4: Exploration of the ulnar artery
The ulnar artery is identified after a cutting through the fascia at the distal forearm. The flexor carpi ulnaris muscle provides as anatomic landmark as the ulnar artery is situated right medial to it. The preparation is extended to the palm and the palmar aponeurosis as well as the short palmar muscles are opened to gain access to the superficial palmar arch.
Step 5: Examine the patency of the ulnar artery
Restore the blood flow and check for the patency of the ulnar artery.
- The ulnar artery presents stiff and thrombosed along a distance of 3 cm. Proper visualization of the actual extent of vascular damage may only be achieved under sufficient perfusion.
- Use patency tests such as the double occlusion or milking test to check for minor blood flow in the ulnar artery.
Step 6: Excise the aneurismatic segment of the ulnar artery
Place vascular clips before and after the excision margins and use microscissors to obtain straight and smooth edges when excising the vessel.
- Measure the vascular segment in vivo as it shrinks after excision.
Step 7: Reconstruction of the ulnar artery
Obtain a vein graft from the distal forearm and use standard microsurgery techniques to place the vein in a reversed direction as an interposition graft.
- Suture sizes of 8-0 to 10-0 have proven to be appropriate depending on the respective blood vessels.
- Check for patency and bleeding.
Step 8: Sonographic examination 3 month postoperative
Perform sonographic examinations of the patient in regular follow-up consultations and check for patency of the vascular reconstruction in addition to clincal examinations and the reported subjective symptoms.
- Only initiate an angiography if a patent blood flow remains elusive with non-invasive imaging (e.g. ultrasound, MRI, CT).
- Start the procedure under blood arrest to optimize visualization. Hereby, one may obtain stasis in a first step to check for the course of superficial veins and wrap the upper extremity in a separate second step to minimize bleeding.
- Remember and paint anatomic landmarks (Arteries, hamate, FCU) before surgery.
- Always restore the blood flow and check for patency before starting a vascular reconstruction.
- Depending on the extent of the vascular damage, reconstruction may be limited if the superficial or deep palmar arch or its branches are involved.
References
- Schröttle A, Czihal M, Lottspeich C, Kuhlencordt P, Nowak D, Hoffmann U. Hypothenar hammer syndrome. Vasa. 2015 May;44(3):179-85. doi: 10.1024/0301-1526/a000427. PMID: 26098321.
- Elhadhri S, Chaouch N, Boughanmi K, Zlitni M, Hentgen B, Fallouh A. Hypothenar hammer syndrome associated with rapidly evolving ulnar false aneurysm. J Med Vasc. 2022 Jul-Aug;47(3):153-156. doi: 10.1016/j.jdmv.2022.07.001. Epub 2022 Jul 28. PMID: 36055686.
- Piessat C, De Almeida YK, Athlani L. Hypothenar hammer syndrome: outcomes after ulnar artery reconstruction with autologous vein graft. Hand Surg Rehabil. 2023 Jun;42(3):203-207. doi: 10.1016/j.hansur.2023.02.008. Epub 2023 Mar 7. PMID: 36893887.