Anterior Cervical Surgery for the Treatment of Hirayama Disease

OBJECTIVE: To provide a quantitative assessment of clinical outcomes of anterior cervical surgery for patients with Hirayama disease. METHODS: Nineteen patients undergoing anterior cervical surgery were retrospectively collected, and preoperative and postoperative clinical and radiographic data were compared. RESULTS: All patients had a mean follow-up time of 72.5 +/- 30.6 months. Tremor in 6 of 14 patients and cold paralysis in 8 patients were resolved after operation. Grip strength of upper extremities was significantly improved (preoperative 15.67 +/- 2.74 kg vs. postoperative 19.82 +/- 2.89 kg, P < 0.001). Postoperative cervical lordosis was significantly increased to 6.41 +/- 4.39 mm from 2.70 +/- 4.61 mm (P < 0.001). The overall range of cervical flexed motion was significantly decreased (preoperative 33.10 degrees +/- 10.60 degrees vs. postoperative 13.55 degrees +/- 6.69 degrees, P < 0.001), with segmental range of C5-6 (preoperative 12.52 degrees +/- 7.13 degrees vs. postoperative 7.04 degrees +/- 3.75 degrees, P = 0.002) and C6-7 (preoperative 9.01 degrees +/- 5.01 degrees vs. postoperative 5.73 degrees +/- 2.74 degrees, P = 0.014) contributing significantly to the improvement. Postoperative angle mobility of C3-4 to C6-7 was significantly decreased (P < 0.001). Postoperative neutral magnetic resonance imaging showed the transverse area of spinal cord of C6 (P = 0.016) and C7 (P = 0.021) was significantly increased. CONCLUSIONS: Anterior cervical surgery can provide clinical efficacy and imaging improvement, including reduced range of cervical flexed motion and angle mobility of lower cervical spine and increased cervical lordosis and spinal cord area.