. The following items were assessed before and/or a month postoperatively; six basic characteristics (Hattori's classification, symptom duration, comorbidity, Pavlof ratio, dynamic instability of cervical spine and cervical intramedullary high intensity change); one motor and one sensory function in the lower and upper extremities, respectively; two walking abilities; one manual dexterity. After division into the elderly group (>or =65 years) and non-elderly group (65 years>)