OBJECTIVETo measure imaging data of occipitocervical angle in healthy people at different ages by X-ray.

METHODSOne hundred and fifty asymptomatic volunteers(75 males and 75 females) aged from 20 and 70 years old with an average of(44.83±13.88) years old were divided into 5 groups according to different ages(20 to 29 years old, 30 to 39 years old, 40 to 49 years old, 50 to 59 years old and 60 to 70 years old), and 30 people in each group. All people underwent lateral radiography of neck on neutral position. McGregor line (the lowest connection line between upper margin of hard palate and occipital scales of plating), occipitocervical angle(OCA) formed by edge of C2 vertebral body, takami's occipitocervical angle formed between connection line of posterior marginal of C2 vertebral body and parallel lines of hard palate were collected. The data were performed statistical analysis according to gender and different ages, and analyzed correlation between OCA and TOCA.

RESULTSOCA of 75 males at different ages were (14.71±3.09)° and(14.22±4.27)° in 75 females. TOCA of 75 males at different ages were (90.50±4.63)° and (90.57±6.67) ° in 75 females. There were no statistical difference in OCA and TOCA in people at different ages(<0.05). There were no significant meaning among 5 groups at different ages in OCA and TOCA(>0.05). The relation analysis results showed positive correlation between OCA and TOCA(=0.454, <0.01).

CONCLUSIONSThe paper provided normal values for occipitocervical angle in population of southwestern China between 20 and 70 years old, and results may be useful for posterior occipitocervical fixation and fusion.