Outcome of Tendon Transfer for Monomelic Amyotrophy (Hirayama Disease)

Hirayama Disease: Surgical Restoration of Hand Function

PURPOSE

Hirayama disease (HD) is a rare, nonfamilial, self-limiting, progressive lower cervical myelopathy, resulting in debilitating distal upper-extremity motor deficits, mimicking high ulnar neuropathy, lower trunk brachial plexopathy, or C8-T1 radiculopathy. Although most literature focuses on pathophysiology and prevention of disease progression, there remains limited discussion regarding treatment to improve upper-extremity function in patients with stable disease. The upper-extremity manifestations of HD are reviewed along with surgical options for restoring hand function.

METHODS

A retrospective review of patients with HD who underwent reconstruction to improve hand function was undertaken. Demographic data, preoperative electrodiagnostic and electromyographic, and physical examination findings were collected. Outcome data involved postoperative grip, pinch, and functional assessment documented on clinical visits. Qualitative descriptions of the surgical techniques are described.

RESULTS

Among six patients identified, four met the inclusion criteria and underwent tendon transfers and selected joint arthrodeses. All patients were diagnosed as teenagers, were right hand-dominant, and three were male. Unilateral symptoms were present in one patient and were bilateral in the rest. All patients were treated with tendon transfers for thumb opposition, grasp, anticlaw, and thumb interphalangeal joint arthrodesis. All patients had postoperative grip strength improvement. The average follow-up was 3.2 years.

CONCLUSIONS

Hirayama disease is a rare disease often managed by spine surgeons and neurologists who may be unaware of options for restoring hand function deficits. Technical strategies and outcomes of improving hand function in HD have not been adequately described. Surgical options to improve hand function are tailored to the deficits and include tendon transfers, select joint arthrodeses, and/or tenodeses. Risk of disease progression and expectations following hand reconstruction must be managed carefully.

TYPE OF STUDY LEVEL OF EVIDENCE

Therapeutic V.

Tendon Transfers to Improve Grip and Pinch in Patients with Sporadic Inclusion Body Myositis

Background

Sporadic inclusion body myositis (sIBM) is a rare and slowly progressive skeletal muscle disease that can cause hand dysfunction, which is a major source of disability. Tendon transfers have been reliably used to improve function in other neuromuscular settings. Given that sIBM patients often present with flexion impairments and mostly functioning extensors, we investigated the potential opportunity for tendon transfer surgery to improve hand dysfunction in sIBM patients.

Methods

We conducted a scoping review for studies of sIBM and tendon transfers, extracted descriptions of hand function and surgical technique, and recorded results in terms of hand function. We also conducted an institutional review board-approved survey with 470 participants to determine baseline patient-reported function and to determine participant perceptions and expectations for tendon transfer surgery to improve hand function in sIBM.

Results

We identified three published case reports on tendon transfers in sIBM patients with subjectively improved grip and pinch strength, but standardized measures of hand function or quality-of-life were not reported. Within the surveyed cohort, half of participants reported that they would consider surgery, yet only 8% had been referred to a hand surgeon. Fifty four percent of participants reported that they would consider surgery if there would be 1-2 years of benefit after surgery. All participants who would consider surgery also had significant upper extremity disability.

Discussion

Tendon transfer surgery has the potential to improve quality-of-life for sIBM patients, and there is significant patient interest in this approach. To objectively assess its efficacy, we propose conducting a surgical trial.

Do patients with Hirayama disease require surgical treatment? A review of the literature

The main clinic characteristic of Hirayama disease (HD) is atrophy of the distal muscles in the upper limbs. Recently, an increasing number of HD cases have been reported. Many HD patients have persistently progressive symptoms and conservative treatments failed. This article aims to review the current status of the field and summarizes the main surgical treatment options for patients with HD. A comprehensive search of the PubMed and the Web of Science databases was conducted from their inception to September 15th, 2022. Search terms included "juvenile muscular atrophy of upper extremity", "Hirayama disease" and "surgery". A total of 169 relevant publications were identified and 29 articles were finally reviewed. Current surgical treatments for HD are either anterior cervical surgery or posterior cervical surgery. The two approaches can effectively stop the disease. However, no studies have compared the advantages and limitations of the two surgical methods. The previous view that HD can be improved with conservative treatment has been challenged. In many studies, surgical treatment has been shown to improve the hand function in patients with HD. However, there is still controversy about the methods of anterior and posterior cervical surgery. Future research could focus on exploring the advantages and limitations of different surgeries.