Multilevel anterior cervical discectomy and fusion with plate fixation for juvenile unilateral muscular atrophy of the distal upper extremity accompanied by cervical kyphosis.

STUDY DESIGN: A retrospective clinical study was conducted and related literatures were reviewed.

OBJECT: This study aimed to evaluate outcome of multilevel anterior cervical discectomy and fusion with plate fixation for juvenile unilateral muscular atrophy of the distal upper extremity accompanied by cervical kyphosis.

SUMMARY OF BACKGROUND DATA: Juvenile unilateral muscular atrophy of the distal upper extremity is a rare disease. Traditional treatment uses a neck collar to immobilize neck motion. However, if the disease is accompanied by cervical kyphosis, conservative treatment is difficult to correct cervical kyphosis and the prognosis is worsened. Therefore, it is important to initially apply surgical treatment for juvenile unilateral muscular atrophy accompanied with cervical kyphosis.

METHODS: From March 2008 to May 2010, 4 patients were transferred to our spine medical center because of a history of slowly progressive distal weakness and atrophy of their hands and forearms. Four patients were diagnosed with Hirayama disease accompanied with cervical kyphosis based on their clinical representations and radiologic findings. After conservative treatment failed, these patients underwent multilevel anterior cervical discectomy and fusion with plate fixation. The clinical outcomes were retrospectively evaluated with follow-up ranging from 1.5 to 3 years.

RESULTS: The clinical and radiologic follow-up indicated satisfactory clinical relief from symptoms, cervical sagittal alignment and cervical spinal canal volume, for all the patients. Within 6 months after surgery, the JOA score improved from a preoperative average of 14 to a postoperative average of 16.3; JOA recovery rates of all patients were more than good level. The muscle strengths of intrinsic muscles, wrist flexors and extensors, and biceps and triceps muscle improved on average by 1 grade. No complications occurred.

CONCLUSIONS: Hirayama disease is a rare disease, a proper diagnosis of which can be made based on significant clinical symptoms and neurological imaging (dynamic MRI). The primary results from this study showed the tendency that multilevel anterior cervical discectomy and fusion with plate fixation is a preferred treatment for patients showing anterior effacement and apparent cervical kyphosis.