Radiological Features Of Degenerative Cervical Kyphosis And Relationship Between Sagittal Parameters

Objective To investigate the radiological features of degenerative cervical kyphosis(DCK)and the relationship between cervical sagittal parameters.MethodsThe quality of life score and imaging data of 89 patients with DCK admitted to our hospital from February 2019 to February 2022 were retrospectively analyzed.There were 47 males and 42 females,with an average age of 48.43±13.35 years(range,25-81years).Quality of life scores included visual analogue scale(VAS)score and neck disability index(NDI).The imaging data included C0-C2 angle,C2-C7 angle,C3-C7 inclination of zygapophyseal joints,C7 slope(C7S),cervical sagittal vertical axis(c SVA),kyphosis range,and kyphosis focal.The patients were grouped by gender,and the differences of the above parameters between the two groups were compared.Pearson correlation was used to analyze the relationship between age,quality of life scores,and cervical sagittal parameters,and the relationship between cervical sagittal parameters.ResultsThe preoperative VAS score was 0-9(mean,4.3),NDI was 16%-44%(mean,30.0%).There was no significant difference in VAS score and NDI between male and female groups(P>0.05).The kyphosis range of cervical spines was C3-5 in 3 cases,C3-6in 41 cases,C3-7 in 30 cases,C4-6 in 4 cases,C4-7 in 10 cases,C5-7 in 1 case,and the kyphosis focal was mostly located between C4-C5(78/89,87.64%).The C3-C7 inclination of zygapophyseal joints were(60.25±5.56)°,(55.42±5.77)°,(53.03±6.33)°,(58.39±7.27)°,and(64.70±6.40)°,respectively.The C0-C2 angle,C2-C7 angle,C7 S,and c SVA were(–23.81±6.74)°,(10.15±2.94)°,(15.31±4.59)°,and(2.37±1.19)mm,respectively.The C7 S and c SVA of males were significantly larger than females(P<0.05),with no significant difference in other parameters between male and female groups(P>0.05).VAS score and NDI were negatively correlated with C0-C2 angle(P<0.05),and positively correlated with C2-C7 angle and c SVA(P<0.05);VAS score was negatively correlated with C7S(P<0.05).Except VAS,NDI and all cervical sagittal parameters were affected by age.Age was positively correlated with NDI,C7 S,and c SVA(P<0.05),and negatively correlated with C0-C2 angle and C2-C7 angle(P<0.05).The correlation analysis of cervical sagittal parameters showed that C0-C2 angle was negatively correlated with C2-C7 angle and c SVA(P<0.05).C7 S was negatively correlated with C2-C7 angle(P<0.05)and positively correlated with c SVA(P<0.05).There was no correlation among other parameters(P>0.05).ConclusionThe inclination of zygapophyseal joints of cervical spines of DCK patients is Ushaped in the kyphosis range,and the inclination at the kyphosis focal is the smallest.When cervical degenerative kyphosis occurs,in addition to the interaction of sagittal parameters,age,gender,neck pain,and dysfunction will also affect the cervical sagittal balance.Furthermore,cervical curvature and morphological changes are not purely local problems.