CAN anterior cervical fusion procedures prevent the progression of the natural course of Hirayama disease? An ambispective cohort analysis.

OBJECTIVE: To clarify the effectiveness of anterior cervical fusion (ACF) in the treatment of Hirayama disease (HD).

METHODS: Sixty-nine HD patients who accepted ACF procedures underwent dynamic F-waves before and soon after operation, and 36 of the 69 patients underwent pre- and postoperative magnetic resonance imaging (MRI). Motor unit number estimation, handgrip strength (HGS) and disabilities of arm, shoulder and hand (DASH) were performed in these 36 HD patients and in the other 24 patients who accepted neither neck-collar support nor operation, and these tests were reassessed about one year after initial test.

RESULTS: Postoperatively, dynamic F-wave abnormalities were observed in fewer HD cases (2/69 vs. 25/69), and neck-flexion MRI abnormalities decreased significantly (P < 0.05). Compared with motor unit loss in patients who were untreated, follow-up analysis demonstrated no differences in motor unit, HGS or DASH in HD patients who underwent operation (P > 0.05), and mild recovery of motor units was observed in patients with preoperative abnormal dynamic F-waves (P < 0.05).

CONCLUSIONS: ACF procedures can immediately remove neck-flexion abnormalities and prevent or delay the progression of HD.

SIGNIFICANCE: ACF procedures may provide effective, reliable and alternative methods for the treatment of HD, especially in HD patients with functional evidence of neck-flexion abnormalities.