Comparative Analysis of Characteristics of Lower- and Mid-Cervical Spine Injuries in the Elderly.

Introduction: Elderly patients have a higher frequency of upper cervical fractures caused by minor trauma; nevertheless, the clinical differences between mid- and lower-cervical (C6-C7) injuries are unclear. The aim of this study was to compare the epidemiology of lower- and mid-cervical injuries in the elderly. Methods: This multicenter, retrospective study included 451 patients aged 65 years or older who had mid- or lower-cervical fractures/dislocations. Patients' demographic and treatment data were examined and compared based on mid- and lower-cervical injuries. Results: There were 139 patients (31%) with lower-cervical injuries and 312 (69%) with mid-cervical injuries. High-energy trauma (60% vs. 47%, p=0.025) and dislocation (55% vs. 45%, p=0.054) were significantly experienced more often by elderly patients with lower-cervical injuries than by patients with mid-cervical injuries. Although the incidence of key muscle weakness at the C5 to T1 levels were all significantly lower in patients with lower-cervical injuries than those with mid-cervical injuries, impairments at C5 occurred in 49% of them, and at C6, in 65%. No significant differences were found in the rates of death, pneumonia, or tracheostomy requirements, and no significant differences existed in ambulation or ASIA impairment scale grade for patients after 6 months of treatment. Conclusions: Elderly patients with lower-cervical fractures/dislocations were injured by high-energy trauma significantly more often than patients with mid-cervical injuries. Furthermore, half of the patients with lower-cervical injuries had mid-cervical level neurological deficits with a relatively high rate of respiratory complications.