Upper Extremity Surgery in Hirayama Disease: A Modification of the Current Algorithm

Area of Science:

• Neurology
• Orthopedic Surgery

Background:

• Hirayama disease (HD) is a rare, nonfamilial amyotrophy causing forearm and hand muscle atrophy and weakness.
• Current treatments for HD include conservative measures and spinal surgery, but upper extremity surgical options are not well-established.

Purpose of the Study:

• To present a case series of HD patients treated with nerve and tendon transfers and joint fusions.
• To conduct a literature review of upper extremity surgical interventions for HD.

Main Methods:

• Retrospective review of three HD patients (four limbs) treated with nerve and tendon transfers and fusion.
• Literature search on PubMed for studies on surgical treatment of HD using terms like "Hirayama disease" and "upper extremity surgery."

Main Results:

• Three HD patients (four limbs) with intrinsic muscle and thenar/hypothenar atrophy underwent surgical treatment.
• Procedures included anterior interosseous (AIN) to ulnar motor nerve transfer and thumb metacarpophalangeal joint fusion with Zancolli lasso.
• All patients showed subjective and objective functional improvements postoperatively.

Conclusions:

• Upper extremity surgery, including nerve transfers, offers a successful treatment option for Hirayama disease.
• This study represents the largest case series and first literature review of such interventions in HD.